diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index bdeda20e..7d542ed8 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -38,31 +38,28 @@ jobs:
     name: Test and Collect Coverage
     runs-on: ubuntu-latest
     needs: lint
+    env:
+      RUST_TOOLCHAIN: 1.88.0
     steps:
       - uses: actions/checkout@v4
         with:
           fetch-depth: 0
 
-      - name: Cache dependencies
-        uses: actions/cache@v4
+      - name: Install Rust toolchain
+        uses: dtolnay/rust-toolchain@master
         with:
-          path: |
-            ~/.cargo/registry
-            ~/.cargo/git
-            target
-          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}
-          restore-keys: |
-            ${{ runner.os }}-cargo-
+          toolchain: ${{ env.RUST_TOOLCHAIN }}
+          components: llvm-tools-preview
+
+      - name: Cache using Swatinem/rust-cache
+        uses: Swatinem/rust-cache@v2
 
       - name: Install Protobuf compiler
         run: sudo apt-get install -y protobuf-compiler
 
-      - name: Install cargo-llvm-cov
+      - name: Install cargo tools
         run: |
           cargo install cargo-llvm-cov --locked
-
-      - name: Install cargo-nextest
-        run: |
           cargo install cargo-nextest --locked
 
       - name: Run tests with nextest and generate coverage
diff --git a/Cargo.lock b/Cargo.lock
index d50550f0..e4a3a97c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2,15 +2,6 @@
 # It is not intended for manual editing.
 version = 4
 
-[[package]]
-name = "addr2line"
-version = "0.24.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dfbe277e56a376000877090da837660b4427aad530e3028d44e0bffe4f89a1c1"
-dependencies = [
- "gimli",
-]
-
 [[package]]
 name = "adler2"
 version = "2.0.1"
@@ -31,9 +22,9 @@ dependencies = [
 
 [[package]]
 name = "aho-corasick"
-version = "1.1.3"
+version = "1.1.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8e60d3430d3a69478ad0993f19238d2df97c507009a52b3c10addcd7f6bcb916"
+checksum = "ddd31a130427c27518df266943a5308ed92d4b226cc639f5a8f1002816174301"
 dependencies = [
  "memchr",
 ]
@@ -46,15 +37,15 @@ checksum = "683d7910e743518b0e34f1186f92494becacb047c7b6bf616c96772180fef923"
 
 [[package]]
 name = "anstyle"
-version = "1.0.11"
+version = "1.0.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "862ed96ca487e809f1c8e5a8447f6ee2cf102f846893800b20cebdf541fc6bbd"
+checksum = "5192cca8006f1fd4f7237516f40fa183bb07f8fbdfedaa0036de5ea9b0b45e78"
 
 [[package]]
 name = "anyhow"
-version = "1.0.99"
+version = "1.0.100"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b0674a1ddeecb70197781e945de4b3b8ffb61fa939a5597bcf48503737663100"
+checksum = "a23eb6b1614318a8071c9b2521f36b424b2c83db5eb3a0fead4a6c0809af6e61"
 
 [[package]]
 name = "arc-swap"
@@ -64,15 +55,13 @@ checksum = "69f7f8c3906b62b754cd5326047894316021dcfe5a194c8ea52bdd94934a3457"
 
 [[package]]
 name = "async-compression"
-version = "0.4.29"
+version = "0.4.32"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5bee399cc3a623ec5a2db2c5b90ee0190a2260241fbe0c023ac8f7bab426aaf8"
+checksum = "5a89bce6054c720275ac2432fbba080a66a2106a44a1b804553930ca6909f4e0"
 dependencies = [
  "compression-codecs",
  "compression-core",
- "flate2",
  "futures-core",
- "memchr",
  "pin-project-lite",
  "tokio",
 ]
@@ -169,21 +158,6 @@ dependencies = [
  "tower-service",
 ]
 
-[[package]]
-name = "backtrace"
-version = "0.3.75"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6806a6321ec58106fea15becdad98371e28d92ccbc7c8f1b3b6dd724fe8f1002"
-dependencies = [
- "addr2line",
- "cfg-if",
- "libc",
- "miniz_oxide",
- "object",
- "rustc-demangle",
- "windows-targets 0.52.6",
-]
-
 [[package]]
 name = "base64"
 version = "0.22.1"
@@ -201,11 +175,11 @@ dependencies = [
 
 [[package]]
 name = "bindgen"
-version = "0.72.0"
+version = "0.72.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4f72209734318d0b619a5e0f5129918b848c416e122a3c4ce054e03cb87b726f"
+checksum = "993776b509cfb49c750f11b8f07a46fa23e0a1386ffc01fb1e7d343efc387895"
 dependencies = [
- "bitflags 2.9.3",
+ "bitflags 2.10.0",
  "cexpr",
  "clang-sys",
  "itertools 0.13.0",
@@ -225,9 +199,9 @@ checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"
 
 [[package]]
 name = "bitflags"
-version = "2.9.3"
+version = "2.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "34efbcccd345379ca2868b2b2c9d3782e9cc58ba87bc7d79d5b53d9c9ae6f25d"
+checksum = "812e12b5285cc515a9c72a5c1d3b6d46a19dac5acfef5265968c166106e31dd3"
 
 [[package]]
 name = "block-buffer"
@@ -265,10 +239,11 @@ dependencies = [
 
 [[package]]
 name = "cc"
-version = "1.2.34"
+version = "1.2.44"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "42bc4aea80032b7bf409b0bc7ccad88853858911b7713a8062fdc0623867bedc"
+checksum = "37521ac7aabe3d13122dc382493e20c9416f299d2ccd5b3a5340a2570cdeb0f3"
 dependencies = [
+ "find-msvc-tools",
  "jobserver",
  "libc",
  "shlex",
@@ -285,9 +260,9 @@ dependencies = [
 
 [[package]]
 name = "cfg-if"
-version = "1.0.3"
+version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2fd1289c04a9ea8cb22300a459a72a385d7c73d3259e2ed7dcb2af674838cfa9"
+checksum = "9330f8b2ff13f34540b44e946ef35111825727b38d33286ef986142615121801"
 
 [[package]]
 name = "cfg_aliases"
@@ -308,15 +283,13 @@ dependencies = [
 
 [[package]]
 name = "compression-codecs"
-version = "0.4.29"
+version = "0.4.31"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c7eea68f0e02c2b0aa8856e9a9478444206d4b6828728e7b0697c0f8cca265cb"
+checksum = "ef8a506ec4b81c460798f572caead636d57d3d7e940f998160f52bd254bf2d23"
 dependencies = [
  "compression-core",
  "flate2",
- "futures-core",
  "memchr",
- "pin-project-lite",
 ]
 
 [[package]]
@@ -433,9 +406,35 @@ dependencies = [
 
 [[package]]
 name = "d-engine"
-version = "0.1.4"
+version = "0.2.0"
+dependencies = [
+ "d-engine-client",
+ "d-engine-server",
+]
+
+[[package]]
+name = "d-engine-client"
+version = "0.2.0"
 dependencies = [
  "arc-swap",
+ "bytes",
+ "d-engine-proto",
+ "futures",
+ "mockall",
+ "rand",
+ "serde",
+ "tokio",
+ "tokio-stream",
+ "tonic",
+ "tonic-health",
+ "tracing",
+ "tracing-test",
+]
+
+[[package]]
+name = "d-engine-core"
+version = "0.1.0"
+dependencies = [
  "async-compression",
  "async-stream",
  "bincode",
@@ -444,25 +443,20 @@ dependencies = [
  "crc32fast",
  "crossbeam",
  "crossbeam-skiplist",
+ "d-engine-proto",
  "dashmap",
- "flate2",
  "futures",
  "http-body",
  "http-body-util",
- "hyper",
  "lru",
  "memmap2",
  "metrics",
  "mockall",
  "nanoid",
  "nix",
- "once_cell",
  "parking_lot",
  "prost",
  "rand",
- "rcgen",
- "ring",
- "rocksdb",
  "serde",
  "serial_test",
  "sha2",
@@ -472,17 +466,76 @@ dependencies = [
  "tokio",
  "tokio-stream",
  "tokio-tar",
- "tokio-util",
  "tonic",
- "tonic-build",
  "tonic-health",
  "tracing",
- "tracing-subscriber",
  "tracing-test",
  "uuid",
+]
+
+[[package]]
+name = "d-engine-docs"
+version = "0.2.0"
+dependencies = [
+ "d-engine-server",
+ "tokio",
+ "tracing",
+]
+
+[[package]]
+name = "d-engine-proto"
+version = "0.2.0"
+dependencies = [
+ "bytes",
+ "prost",
+ "serde",
+ "tonic",
+ "tonic-build",
+ "tracing",
  "vergen",
 ]
 
+[[package]]
+name = "d-engine-server"
+version = "0.2.0"
+dependencies = [
+ "arc-swap",
+ "async-compression",
+ "bincode",
+ "bytes",
+ "config",
+ "crc32fast",
+ "crossbeam",
+ "crossbeam-skiplist",
+ "d-engine-core",
+ "d-engine-proto",
+ "d-engine-server",
+ "dashmap",
+ "futures",
+ "http-body",
+ "http-body-util",
+ "metrics",
+ "mockall",
+ "nanoid",
+ "parking_lot",
+ "prost",
+ "rcgen",
+ "rocksdb",
+ "serde",
+ "serial_test",
+ "temp-env",
+ "tempfile",
+ "tokio",
+ "tokio-stream",
+ "tokio-tar",
+ "tokio-util",
+ "tonic",
+ "tonic-health",
+ "tracing",
+ "tracing-test",
+ "uuid",
+]
+
 [[package]]
 name = "dashmap"
 version = "5.5.3"
@@ -498,9 +551,9 @@ dependencies = [
 
 [[package]]
 name = "deranged"
-version = "0.4.0"
+version = "0.5.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9c9e6a11ca8224451684bc0d7d5a7adbf8f2fd6887261a1cfc3c0432f9d4068e"
+checksum = "ececcb659e7ba858fb4f10388c250a7252eb0a27373f1a72b8748afdd248e587"
 dependencies = [
  "powerfmt",
 ]
@@ -535,12 +588,12 @@ checksum = "877a4ace8713b0bcf2a4e7eec82529c029f1d0619886d18145fea96c3ffe5c0f"
 
 [[package]]
 name = "errno"
-version = "0.3.13"
+version = "0.3.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "778e2ac28f6c47af28e4907f13ffd1e1ddbd400980a9abd7c8df189bf578a5ad"
+checksum = "39cab71617ae0d63f51a36d69f866391735b51691dbda63cf6f96d042b63efeb"
 dependencies = [
  "libc",
- "windows-sys 0.60.2",
+ "windows-sys 0.61.2",
 ]
 
 [[package]]
@@ -561,6 +614,12 @@ dependencies = [
  "windows-sys 0.60.2",
 ]
 
+[[package]]
+name = "find-msvc-tools"
+version = "0.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "52051878f80a721bb68ebfbc930e07b65ba72f2da88968ea5c06fd6ca3d3a127"
+
 [[package]]
 name = "fixedbitset"
 version = "0.5.7"
@@ -569,12 +628,11 @@ checksum = "1d674e81391d1e1ab681a28d99df07927c6d4aa5b027d7da16ba32d1d21ecd99"
 
 [[package]]
 name = "flate2"
-version = "1.1.2"
+version = "1.1.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4a3d7db9596fecd151c5f638c0ee5d5bd487b6e0ea232e5dc96d5250f6f94b1d"
+checksum = "bfe33edd8e85a12a67454e37f8c75e730830d83e313556ab9ebf9ee7fbeb3bfb"
 dependencies = [
  "crc32fast",
- "libz-sys",
  "miniz_oxide",
 ]
 
@@ -687,9 +745,9 @@ dependencies = [
 
 [[package]]
 name = "generic-array"
-version = "0.14.7"
+version = "0.14.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "85649ca51fd72272d7821adaf274ad91c288277713d9c18820d8499a7ff69e9a"
+checksum = "4bb6743198531e02858aeaea5398fcc883e71851fcbcb5a2f773e2fb6cb1edf2"
 dependencies = [
  "typenum",
  "version_check",
@@ -703,27 +761,21 @@ checksum = "335ff9f135e4384c8150d6f27c6daed433577f86b4750418338c01a1a2528592"
 dependencies = [
  "cfg-if",
  "libc",
- "wasi 0.11.1+wasi-snapshot-preview1",
+ "wasi",
 ]
 
 [[package]]
 name = "getrandom"
-version = "0.3.3"
+version = "0.3.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "26145e563e54f2cadc477553f1ec5ee650b00862f0a58bcd12cbdc5f0ea2d2f4"
+checksum = "899def5c37c4fd7b2664648c28120ecec138e4d395b459e5ca34f9cce2dd77fd"
 dependencies = [
  "cfg-if",
  "libc",
  "r-efi",
- "wasi 0.14.3+wasi-0.2.4",
+ "wasip2",
 ]
 
-[[package]]
-name = "gimli"
-version = "0.31.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "07e28edb80900c19c28f1072f2e8aeca7fa06b23cd4169cefe1af5aa3260783f"
-
 [[package]]
 name = "glob"
 version = "0.3.3"
@@ -742,7 +794,7 @@ dependencies = [
  "futures-core",
  "futures-sink",
  "http",
- "indexmap 2.11.0",
+ "indexmap 2.12.0",
  "slab",
  "tokio",
  "tokio-util",
@@ -772,6 +824,12 @@ dependencies = [
  "foldhash",
 ]
 
+[[package]]
+name = "hashbrown"
+version = "0.16.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5419bdc4f6a9207fbeba6d11b604d481addf78ecd10c11ad51e76c2f6482748d"
+
 [[package]]
 name = "heck"
 version = "0.5.0"
@@ -862,9 +920,9 @@ dependencies = [
 
 [[package]]
 name = "hyper-util"
-version = "0.1.16"
+version = "0.1.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8d9b05277c7e8da2c93a568989bb6207bef0112e8d17df7a6eda4a3cf143bc5e"
+checksum = "3c6995591a8f1380fcb4ba966a252a4b29188d51d2b89e3a252f5305be65aea8"
 dependencies = [
  "bytes",
  "futures-channel",
@@ -875,7 +933,7 @@ dependencies = [
  "hyper",
  "libc",
  "pin-project-lite",
- "socket2 0.6.0",
+ "socket2 0.6.1",
  "tokio",
  "tower-service",
  "tracing",
@@ -893,23 +951,12 @@ dependencies = [
 
 [[package]]
 name = "indexmap"
-version = "2.11.0"
+version = "2.12.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f2481980430f9f78649238835720ddccc57e52df14ffce1c6f37391d61b563e9"
+checksum = "6717a8d2a5a929a1a2eb43a12812498ed141a0bcfb7e8f7844fbdbe4303bba9f"
 dependencies = [
  "equivalent",
- "hashbrown 0.15.5",
-]
-
-[[package]]
-name = "io-uring"
-version = "0.7.10"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "046fa2d4d00aea763528b4950358d0ead425372445dc8ff86312b3c69ff7727b"
-dependencies = [
- "bitflags 2.9.3",
- "cfg-if",
- "libc",
+ "hashbrown 0.16.0",
 ]
 
 [[package]]
@@ -942,15 +989,15 @@ version = "0.1.34"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9afb3de4395d6b3e67a780b6de64b51c978ecf11cb9a462c66be7d4ca9039d33"
 dependencies = [
- "getrandom 0.3.3",
+ "getrandom 0.3.4",
  "libc",
 ]
 
 [[package]]
 name = "js-sys"
-version = "0.3.77"
+version = "0.3.82"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1cfaf33c695fc6e08064efbc1f72ec937429614f25eef83af942d0e227c3a28f"
+checksum = "b011eec8cc36da2aab2d5cff675ec18454fad408585853910a202391cf9f8e65"
 dependencies = [
  "once_cell",
  "wasm-bindgen",
@@ -964,29 +1011,29 @@ checksum = "bbd2bcb4c963f2ddae06a2efc7e9f3591312473c50c6685e1f298068316e66fe"
 
 [[package]]
 name = "libc"
-version = "0.2.175"
+version = "0.2.177"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6a82ae493e598baaea5209805c49bbf2ea7de956d50d7da0da1164f9c6d28543"
+checksum = "2874a2af47a2325c2001a6e6fad9b16a53b802102b528163885171cf92b15976"
 
 [[package]]
 name = "libloading"
-version = "0.8.8"
+version = "0.8.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "07033963ba89ebaf1584d767badaa2e8fcec21aedea6b8c0346d487d49c28667"
+checksum = "d7c4b02199fee7c5d21a5ae7d8cfa79a6ef5bb2fc834d6e9058e89c825efdc55"
 dependencies = [
  "cfg-if",
- "windows-targets 0.53.3",
+ "windows-link",
 ]
 
 [[package]]
 name = "libredox"
-version = "0.1.9"
+version = "0.1.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "391290121bad3d37fbddad76d8f5d1c1c314cfc646d143d7e07a3086ddff0ce3"
+checksum = "416f7e718bdb06000964960ffa43b4335ad4012ae8b99060261aa4a8088d5ccb"
 dependencies = [
- "bitflags 2.9.3",
+ "bitflags 2.10.0",
  "libc",
- "redox_syscall 0.5.17",
+ "redox_syscall 0.5.18",
 ]
 
 [[package]]
@@ -1017,25 +1064,24 @@ dependencies = [
 
 [[package]]
 name = "linux-raw-sys"
-version = "0.9.4"
+version = "0.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cd945864f07fe9f5371a27ad7b52a172b4b499999f1d97574c9fa68373937e12"
+checksum = "df1d3c3b53da64cf5760482273a98e575c651a67eec7f77df96b5b642de8f039"
 
 [[package]]
 name = "lock_api"
-version = "0.4.13"
+version = "0.4.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "96936507f153605bddfcda068dd804796c84324ed2510809e5b2a624c81da765"
+checksum = "224399e74b87b5f3557511d98dff8b14089b3dadafcab6bb93eab67d3aace965"
 dependencies = [
- "autocfg",
  "scopeguard",
 ]
 
 [[package]]
 name = "log"
-version = "0.4.27"
+version = "0.4.28"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "13dc2df351e3202783a1fe0d44375f7295ffb4049267b0f3018346dc122a1d94"
+checksum = "34080505efa8e45a4b816c349525ebe327ceaa8559756f0356cba97ef3bf7432"
 
 [[package]]
 name = "lru"
@@ -1073,15 +1119,15 @@ checksum = "0e7465ac9959cc2b1404e8e2367b43684a6d13790fe23056cc8c6c5a6b7bcb94"
 
 [[package]]
 name = "memchr"
-version = "2.7.5"
+version = "2.7.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "32a282da65faaf38286cf3be983213fcf1d2e2a58700e808f83f4ea9a4804bc0"
+checksum = "f52b00d39961fc5b2736ea853c9cc86238e165017a493d1d5c8eac6bdc4cc273"
 
 [[package]]
 name = "memmap2"
-version = "0.9.8"
+version = "0.9.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "843a98750cd611cc2965a8213b53b43e715f13c37a9e096c6408e69990961db7"
+checksum = "744133e4a0e0a658e1374cf3bf8e415c4052a15a111acd372764c55b4177d490"
 dependencies = [
  "libc",
 ]
@@ -1115,17 +1161,18 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1fa76a2c86f704bdb222d66965fb3d63269ce38518b83cb0575fca855ebb6316"
 dependencies = [
  "adler2",
+ "simd-adler32",
 ]
 
 [[package]]
 name = "mio"
-version = "1.0.4"
+version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "78bed444cc8a2160f01cbcf811ef18cac863ad68ae8ca62092e8db51d51c761c"
+checksum = "69d83b0086dc8ecf3ce9ae2874b2d1290252e2a30720bea58a5c6639b0092873"
 dependencies = [
  "libc",
- "wasi 0.11.1+wasi-snapshot-preview1",
- "windows-sys 0.59.0",
+ "wasi",
+ "windows-sys 0.61.2",
 ]
 
 [[package]]
@@ -1176,7 +1223,7 @@ version = "0.30.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "74523f3a35e05aba87a1d978330aef40f67b0304ac79c1c00b294c9830543db6"
 dependencies = [
- "bitflags 2.9.3",
+ "bitflags 2.10.0",
  "cfg-if",
  "cfg_aliases",
  "libc",
@@ -1194,11 +1241,11 @@ dependencies = [
 
 [[package]]
 name = "nu-ansi-term"
-version = "0.50.1"
+version = "0.50.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d4a28e057d01f97e61255210fcff094d74ed0466038633e95017f5beb68e4399"
+checksum = "7957b9740744892f114936ab4a57b3f487491bbeafaf8083688b16841a4240e5"
 dependencies = [
- "windows-sys 0.52.0",
+ "windows-sys 0.61.2",
 ]
 
 [[package]]
@@ -1216,15 +1263,6 @@ dependencies = [
  "libc",
 ]
 
-[[package]]
-name = "object"
-version = "0.36.7"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "62948e14d923ea95ea2c7c86c71013138b66525b86bdc08d2dcc262bdb497b87"
-dependencies = [
- "memchr",
-]
-
 [[package]]
 name = "once_cell"
 version = "1.21.3"
@@ -1233,9 +1271,9 @@ checksum = "42f5e15c9953c5e4ccceeb2e7382a716482c34515315f7b03532b8b4e8393d2d"
 
 [[package]]
 name = "parking_lot"
-version = "0.12.4"
+version = "0.12.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "70d58bf43669b5795d1576d0641cfb6fbb2057bf629506267a92807158584a13"
+checksum = "93857453250e3077bd71ff98b6a65ea6621a19bb0f559a85248955ac12c45a1a"
 dependencies = [
  "lock_api",
  "parking_lot_core",
@@ -1243,15 +1281,15 @@ dependencies = [
 
 [[package]]
 name = "parking_lot_core"
-version = "0.9.11"
+version = "0.9.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bc838d2a56b5b1a6c25f55575dfc605fabb63bb2365f6c2353ef9159aa69e4a5"
+checksum = "2621685985a2ebf1c516881c026032ac7deafcda1a2c9b7850dc81e3dfcb64c1"
 dependencies = [
  "cfg-if",
  "libc",
- "redox_syscall 0.5.17",
+ "redox_syscall 0.5.18",
  "smallvec",
- "windows-targets 0.52.6",
+ "windows-link",
 ]
 
 [[package]]
@@ -1262,12 +1300,12 @@ checksum = "df94ce210e5bc13cb6651479fa48d14f601d9858cfe0467f43ae157023b938d3"
 
 [[package]]
 name = "pem"
-version = "3.0.5"
+version = "3.0.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "38af38e8470ac9dee3ce1bae1af9c1671fffc44ddfd8bd1d0a3445bf349a8ef3"
+checksum = "1d30c53c26bc5b31a98cd02d20f25a7c8567146caf63ed593a9d87b2775291be"
 dependencies = [
  "base64",
- "serde",
+ "serde_core",
 ]
 
 [[package]]
@@ -1283,7 +1321,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3672b37090dbd86368a4145bc067582552b29c27377cad4e0a306c97f9bd7772"
 dependencies = [
  "fixedbitset",
- "indexmap 2.11.0",
+ "indexmap 2.12.0",
 ]
 
 [[package]]
@@ -1383,9 +1421,9 @@ dependencies = [
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.101"
+version = "1.0.103"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "89ae43fd86e4158d6db51ad8e2b80f313af9cc74f5c0e03ccb87de09998732de"
+checksum = "5ee95bc4ef87b8d5ba32e8b7714ccc834865276eab0aed5c9958d00ec45f49e8"
 dependencies = [
  "unicode-ident",
 ]
@@ -1444,9 +1482,9 @@ dependencies = [
 
 [[package]]
 name = "quote"
-version = "1.0.40"
+version = "1.0.41"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1885c039570dc00dcb4ff087a89e185fd56bae234ddc7f056a945bf36467248d"
+checksum = "ce25767e7b499d1b604768e7cde645d14cc8584231ea6b295e9c9eb22c02e1d1"
 dependencies = [
  "proc-macro2",
 ]
@@ -1511,18 +1549,18 @@ dependencies = [
 
 [[package]]
 name = "redox_syscall"
-version = "0.5.17"
+version = "0.5.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5407465600fb0548f1442edf71dd20683c6ed326200ace4b1ef0763521bb3b77"
+checksum = "ed2bf2547551a7053d6fdfafda3f938979645c44812fbfcda098faae3f1a362d"
 dependencies = [
- "bitflags 2.9.3",
+ "bitflags 2.10.0",
 ]
 
 [[package]]
 name = "regex"
-version = "1.11.2"
+version = "1.12.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "23d7fd106d8c02486a8d64e778353d1cffe08ce79ac2e82f540c86d0facf6912"
+checksum = "843bc0191f75f3e22651ae5f1e72939ab2f72a4bc30fa80a066bd66edefc24d4"
 dependencies = [
  "aho-corasick",
  "memchr",
@@ -1532,9 +1570,9 @@ dependencies = [
 
 [[package]]
 name = "regex-automata"
-version = "0.4.10"
+version = "0.4.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6b9458fa0bfeeac22b5ca447c63aaf45f28439a709ccd244698632f9aa6394d6"
+checksum = "5276caf25ac86c8d810222b3dbb938e512c55c6831a10f3e6ed1c93b84041f1c"
 dependencies = [
  "aho-corasick",
  "memchr",
@@ -1543,9 +1581,9 @@ dependencies = [
 
 [[package]]
 name = "regex-syntax"
-version = "0.8.6"
+version = "0.8.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "caf4aa5b0f434c91fe5c7f1ecb6a5ece2130b02ad2a590589dda5146df959001"
+checksum = "7a2d987857b319362043e95f5353c0535c1f58eec5336fdfcf626430af7def58"
 
 [[package]]
 name = "ring"
@@ -1571,12 +1609,6 @@ dependencies = [
  "librocksdb-sys",
 ]
 
-[[package]]
-name = "rustc-demangle"
-version = "0.1.26"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "56f7d92ca342cea22a06f2121d944b4fd82af56988c270852495420f961d4ace"
-
 [[package]]
 name = "rustc-hash"
 version = "2.1.1"
@@ -1585,22 +1617,22 @@ checksum = "357703d41365b4b27c590e3ed91eabb1b663f07c4c084095e60cbed4362dff0d"
 
 [[package]]
 name = "rustix"
-version = "1.0.8"
+version = "1.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "11181fbabf243db407ef8df94a6ce0b2f9a733bd8be4ad02b4eda9602296cac8"
+checksum = "cd15f8a2c5551a84d56efdc1cd049089e409ac19a3072d5037a17fd70719ff3e"
 dependencies = [
- "bitflags 2.9.3",
+ "bitflags 2.10.0",
  "errno",
  "libc",
  "linux-raw-sys",
- "windows-sys 0.60.2",
+ "windows-sys 0.61.2",
 ]
 
 [[package]]
 name = "rustls"
-version = "0.23.31"
+version = "0.23.34"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c0ebcbd2f03de0fc1122ad9bb24b127a5a6cd51d72604a3f3c50ac459762b6cc"
+checksum = "6a9586e9ee2b4f8fab52a0048ca7334d7024eef48e2cb9407e3497bb7cab7fa7"
 dependencies = [
  "log",
  "once_cell",
@@ -1622,18 +1654,18 @@ dependencies = [
 
 [[package]]
 name = "rustls-pki-types"
-version = "1.12.0"
+version = "1.13.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "229a4a4c221013e7e1f1a043678c5cc39fe5171437c88fb47151a21e6f5b5c79"
+checksum = "94182ad936a0c91c324cd46c6511b9510ed16af436d7b5bab34beab0afd55f7a"
 dependencies = [
  "zeroize",
 ]
 
 [[package]]
 name = "rustls-webpki"
-version = "0.103.4"
+version = "0.103.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0a17884ae0c1b773f1ccd2bd4a8c72f16da897310a98b0e84bf349ad5ead92fc"
+checksum = "2ffdfa2f5286e2247234e03f680868ac2815974dc39e00ea15adc445d0aafe52"
 dependencies = [
  "ring",
  "rustls-pki-types",
@@ -1669,18 +1701,28 @@ checksum = "490dcfcbfef26be6800d11870ff2df8774fa6e86d047e3e8c8a76b25655e41ca"
 
 [[package]]
 name = "serde"
-version = "1.0.219"
+version = "1.0.228"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5f0e2c6ed6606019b4e29e69dbaba95b11854410e5347d525002456dbbb786b6"
+checksum = "9a8e94ea7f378bd32cbbd37198a4a91436180c5bb472411e48b5ec2e2124ae9e"
+dependencies = [
+ "serde_core",
+ "serde_derive",
+]
+
+[[package]]
+name = "serde_core"
+version = "1.0.228"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "41d385c7d4ca58e59fc732af25c3983b67ac852c1a25000afe1175de458b67ad"
 dependencies = [
  "serde_derive",
 ]
 
 [[package]]
 name = "serde_derive"
-version = "1.0.219"
+version = "1.0.228"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5b0276cf7f2c73365f7157c8123c21cd9a50fbbd844757af28ca1f5925fc2a00"
+checksum = "d540f220d3187173da220f885ab66608367b6574e925011a9353e4badda91d79"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -1756,6 +1798,12 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "simd-adler32"
+version = "0.3.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d66dc143e6b11c1eddc06d5c423cfc97062865baf299914ab64caa38182078fe"
+
 [[package]]
 name = "slab"
 version = "0.4.11"
@@ -1780,12 +1828,12 @@ dependencies = [
 
 [[package]]
 name = "socket2"
-version = "0.6.0"
+version = "0.6.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "233504af464074f9d066d7b5416c5f9b894a5862a6506e306f7b816cdd6f1807"
+checksum = "17129e116933cf371d018bb80ae557e889637989d8638274fb25622827b03881"
 dependencies = [
  "libc",
- "windows-sys 0.59.0",
+ "windows-sys 0.60.2",
 ]
 
 [[package]]
@@ -1796,9 +1844,9 @@ checksum = "13c2bddecc57b384dee18652358fb23172facb8a2c51ccc10d74c157bdea3292"
 
 [[package]]
 name = "syn"
-version = "2.0.106"
+version = "2.0.108"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ede7c438028d4436d71104916910f5bb611972c5cfd7f89b8300a8186e6fada6"
+checksum = "da58917d35242480a05c2897064da0a80589a2a0476c9a3f2fdc83b53502e917"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -1822,15 +1870,15 @@ dependencies = [
 
 [[package]]
 name = "tempfile"
-version = "3.21.0"
+version = "3.23.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "15b61f8f20e3a6f7e0649d825294eaf317edce30f82cf6026e7e4cb9222a7d1e"
+checksum = "2d31c77bdf42a745371d260a26ca7163f1e0924b64afa0b688e61b5a9fa02f16"
 dependencies = [
  "fastrand",
- "getrandom 0.3.3",
+ "getrandom 0.3.4",
  "once_cell",
  "rustix",
- "windows-sys 0.60.2",
+ "windows-sys 0.61.2",
 ]
 
 [[package]]
@@ -1870,9 +1918,9 @@ dependencies = [
 
 [[package]]
 name = "time"
-version = "0.3.41"
+version = "0.3.44"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8a7619e19bc266e0f9c5e6686659d394bc57973859340060a69221e57dbc0c40"
+checksum = "91e7d9e3bb61134e77bde20dd4825b97c010155709965fedf0f49bb138e52a9d"
 dependencies = [
  "deranged",
  "itoa",
@@ -1887,15 +1935,15 @@ dependencies = [
 
 [[package]]
 name = "time-core"
-version = "0.1.4"
+version = "0.1.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c9e9a38711f559d9e3ce1cdb06dd7c5b8ea546bc90052da6d06bb76da74bb07c"
+checksum = "40868e7c1d2f0b8d73e4a8c7f0ff63af4f6d19be117e90bd73eb1d62cf831c6b"
 
 [[package]]
 name = "time-macros"
-version = "0.2.22"
+version = "0.2.24"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3526739392ec93fd8b359c8e98514cb3e8e021beb4e5f597b00a0221f8ed8a49"
+checksum = "30cfb0125f12d9c277f35663a0a33f8c30190f4e4574868a330595412d34ebf3"
 dependencies = [
  "num-conv",
  "time-core",
@@ -1903,28 +1951,25 @@ dependencies = [
 
 [[package]]
 name = "tokio"
-version = "1.47.1"
+version = "1.48.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "89e49afdadebb872d3145a5638b59eb0691ea23e46ca484037cfab3b76b95038"
+checksum = "ff360e02eab121e0bc37a2d3b4d4dc622e6eda3a8e5253d5435ecf5bd4c68408"
 dependencies = [
- "backtrace",
  "bytes",
- "io-uring",
  "libc",
  "mio",
  "pin-project-lite",
  "signal-hook-registry",
- "slab",
- "socket2 0.6.0",
+ "socket2 0.6.1",
  "tokio-macros",
- "windows-sys 0.59.0",
+ "windows-sys 0.61.2",
 ]
 
 [[package]]
 name = "tokio-macros"
-version = "2.5.0"
+version = "2.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6e06d43f1345a3bcd39f6a56dbb7dcab2ba47e68e8ac134855e7e2bdbaf8cab8"
+checksum = "af407857209536a95c8e56f8231ef2c2e2aff839b22e07a1ffcbc617e9db9fa5"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -1933,9 +1978,9 @@ dependencies = [
 
 [[package]]
 name = "tokio-rustls"
-version = "0.26.2"
+version = "0.26.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8e727b36a1a0e8b74c376ac2211e40c2c8af09fb4013c60d910495810f008e9b"
+checksum = "1729aa945f29d91ba541258c8df89027d5792d85a8841fb65e8bf0f4ede4ef61"
 dependencies = [
  "rustls",
  "tokio",
@@ -2007,7 +2052,7 @@ version = "0.22.27"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "41fe8c660ae4257887cf66394862d21dbca4a6ddd26f04a3560410406a2f819a"
 dependencies = [
- "indexmap 2.11.0",
+ "indexmap 2.12.0",
  "serde",
  "serde_spanned",
  "toml_datetime",
@@ -2217,15 +2262,15 @@ checksum = "e421abadd41a4225275504ea4d6566923418b7f05506fbc9c0fe86ba7396114b"
 
 [[package]]
 name = "typenum"
-version = "1.18.0"
+version = "1.19.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1dccffe3ce07af9386bfd29e80c0ab1a8205a2fc34e4bcd40364df902cfa8f3f"
+checksum = "562d481066bde0658276a35467c4af00bdc6ee726305698a55b86e61d7ad82bb"
 
 [[package]]
 name = "unicode-ident"
-version = "1.0.18"
+version = "1.0.22"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5a5f39404a5da50712a4c1eecf25e90dd62b613502b7e925fd4e4d19b5c96512"
+checksum = "9312f7c4f6ff9069b165498234ce8be658059c6728633667c526e27dc2cf1df5"
 
 [[package]]
 name = "untrusted"
@@ -2235,11 +2280,11 @@ checksum = "8ecb6da28b8a351d773b68d5825ac39017e680750f980f3a1a85cd8dd28a47c1"
 
 [[package]]
 name = "uuid"
-version = "1.18.0"
+version = "1.18.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f33196643e165781c20a5ead5582283a7dacbb87855d867fbc2df3f81eddc1be"
+checksum = "2f87b8aa10b915a06587d0dec516c282ff295b475d94abf425d62b57710070a2"
 dependencies = [
- "getrandom 0.3.3",
+ "getrandom 0.3.4",
  "js-sys",
  "wasm-bindgen",
 ]
@@ -2290,45 +2335,32 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ccf3ec651a847eb01de73ccad15eb7d99f80485de043efb2f370cd654f4ea44b"
 
 [[package]]
-name = "wasi"
-version = "0.14.3+wasi-0.2.4"
+name = "wasip2"
+version = "1.0.1+wasi-0.2.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6a51ae83037bdd272a9e28ce236db8c07016dd0d50c27038b3f407533c030c95"
+checksum = "0562428422c63773dad2c345a1882263bbf4d65cf3f42e90921f787ef5ad58e7"
 dependencies = [
  "wit-bindgen",
 ]
 
 [[package]]
 name = "wasm-bindgen"
-version = "0.2.100"
+version = "0.2.105"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1edc8929d7499fc4e8f0be2262a241556cfc54a0bea223790e71446f2aab1ef5"
+checksum = "da95793dfc411fbbd93f5be7715b0578ec61fe87cb1a42b12eb625caa5c5ea60"
 dependencies = [
  "cfg-if",
  "once_cell",
  "rustversion",
  "wasm-bindgen-macro",
-]
-
-[[package]]
-name = "wasm-bindgen-backend"
-version = "0.2.100"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2f0a0651a5c2bc21487bde11ee802ccaf4c51935d0d3d42a6101f98161700bc6"
-dependencies = [
- "bumpalo",
- "log",
- "proc-macro2",
- "quote",
- "syn",
  "wasm-bindgen-shared",
 ]
 
 [[package]]
 name = "wasm-bindgen-macro"
-version = "0.2.100"
+version = "0.2.105"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7fe63fc6d09ed3792bd0897b314f53de8e16568c2b3f7982f468c0bf9bd0b407"
+checksum = "04264334509e04a7bf8690f2384ef5265f05143a4bff3889ab7a3269adab59c2"
 dependencies = [
  "quote",
  "wasm-bindgen-macro-support",
@@ -2336,31 +2368,31 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-macro-support"
-version = "0.2.100"
+version = "0.2.105"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8ae87ea40c9f689fc23f209965b6fb8a99ad69aeeb0231408be24920604395de"
+checksum = "420bc339d9f322e562942d52e115d57e950d12d88983a14c79b86859ee6c7ebc"
 dependencies = [
+ "bumpalo",
  "proc-macro2",
  "quote",
  "syn",
- "wasm-bindgen-backend",
  "wasm-bindgen-shared",
 ]
 
 [[package]]
 name = "wasm-bindgen-shared"
-version = "0.2.100"
+version = "0.2.105"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1a05d73b933a847d6cccdda8f838a22ff101ad9bf93e33684f39c1f5f0eece3d"
+checksum = "76f218a38c84bcb33c25ec7059b07847d465ce0e0a76b995e134a45adcb6af76"
 dependencies = [
  "unicode-ident",
 ]
 
 [[package]]
 name = "windows-link"
-version = "0.1.3"
+version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5e6ad25900d524eaabdbbb96d20b4311e1e7ae1699af4fb28c17ae66c80d798a"
+checksum = "f0805222e57f7521d6a62e36fa9163bc891acd422f971defe97d64e70d0a4fe5"
 
 [[package]]
 name = "windows-sys"
@@ -2373,20 +2405,20 @@ dependencies = [
 
 [[package]]
 name = "windows-sys"
-version = "0.59.0"
+version = "0.60.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1e38bc4d79ed67fd075bcc251a1c39b32a1776bbe92e5bef1f0bf1f8c531853b"
+checksum = "f2f500e4d28234f72040990ec9d39e3a6b950f9f22d3dba18416c35882612bcb"
 dependencies = [
- "windows-targets 0.52.6",
+ "windows-targets 0.53.5",
 ]
 
 [[package]]
 name = "windows-sys"
-version = "0.60.2"
+version = "0.61.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f2f500e4d28234f72040990ec9d39e3a6b950f9f22d3dba18416c35882612bcb"
+checksum = "ae137229bcbd6cdf0f7b80a31df61766145077ddf49416a728b02cb3921ff3fc"
 dependencies = [
- "windows-targets 0.53.3",
+ "windows-link",
 ]
 
 [[package]]
@@ -2407,19 +2439,19 @@ dependencies = [
 
 [[package]]
 name = "windows-targets"
-version = "0.53.3"
+version = "0.53.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d5fe6031c4041849d7c496a8ded650796e7b6ecc19df1a431c1a363342e5dc91"
+checksum = "4945f9f551b88e0d65f3db0bc25c33b8acea4d9e41163edf90dcd0b19f9069f3"
 dependencies = [
  "windows-link",
- "windows_aarch64_gnullvm 0.53.0",
- "windows_aarch64_msvc 0.53.0",
- "windows_i686_gnu 0.53.0",
- "windows_i686_gnullvm 0.53.0",
- "windows_i686_msvc 0.53.0",
- "windows_x86_64_gnu 0.53.0",
- "windows_x86_64_gnullvm 0.53.0",
- "windows_x86_64_msvc 0.53.0",
+ "windows_aarch64_gnullvm 0.53.1",
+ "windows_aarch64_msvc 0.53.1",
+ "windows_i686_gnu 0.53.1",
+ "windows_i686_gnullvm 0.53.1",
+ "windows_i686_msvc 0.53.1",
+ "windows_x86_64_gnu 0.53.1",
+ "windows_x86_64_gnullvm 0.53.1",
+ "windows_x86_64_msvc 0.53.1",
 ]
 
 [[package]]
@@ -2430,9 +2462,9 @@ checksum = "32a4622180e7a0ec044bb555404c800bc9fd9ec262ec147edd5989ccd0c02cd3"
 
 [[package]]
 name = "windows_aarch64_gnullvm"
-version = "0.53.0"
+version = "0.53.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "86b8d5f90ddd19cb4a147a5fa63ca848db3df085e25fee3cc10b39b6eebae764"
+checksum = "a9d8416fa8b42f5c947f8482c43e7d89e73a173cead56d044f6a56104a6d1b53"
 
 [[package]]
 name = "windows_aarch64_msvc"
@@ -2442,9 +2474,9 @@ checksum = "09ec2a7bb152e2252b53fa7803150007879548bc709c039df7627cabbd05d469"
 
 [[package]]
 name = "windows_aarch64_msvc"
-version = "0.53.0"
+version = "0.53.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c7651a1f62a11b8cbd5e0d42526e55f2c99886c77e007179efff86c2b137e66c"
+checksum = "b9d782e804c2f632e395708e99a94275910eb9100b2114651e04744e9b125006"
 
 [[package]]
 name = "windows_i686_gnu"
@@ -2454,9 +2486,9 @@ checksum = "8e9b5ad5ab802e97eb8e295ac6720e509ee4c243f69d781394014ebfe8bbfa0b"
 
 [[package]]
 name = "windows_i686_gnu"
-version = "0.53.0"
+version = "0.53.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c1dc67659d35f387f5f6c479dc4e28f1d4bb90ddd1a5d3da2e5d97b42d6272c3"
+checksum = "960e6da069d81e09becb0ca57a65220ddff016ff2d6af6a223cf372a506593a3"
 
 [[package]]
 name = "windows_i686_gnullvm"
@@ -2466,9 +2498,9 @@ checksum = "0eee52d38c090b3caa76c563b86c3a4bd71ef1a819287c19d586d7334ae8ed66"
 
 [[package]]
 name = "windows_i686_gnullvm"
-version = "0.53.0"
+version = "0.53.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9ce6ccbdedbf6d6354471319e781c0dfef054c81fbc7cf83f338a4296c0cae11"
+checksum = "fa7359d10048f68ab8b09fa71c3daccfb0e9b559aed648a8f95469c27057180c"
 
 [[package]]
 name = "windows_i686_msvc"
@@ -2478,9 +2510,9 @@ checksum = "240948bc05c5e7c6dabba28bf89d89ffce3e303022809e73deaefe4f6ec56c66"
 
 [[package]]
 name = "windows_i686_msvc"
-version = "0.53.0"
+version = "0.53.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "581fee95406bb13382d2f65cd4a908ca7b1e4c2f1917f143ba16efe98a589b5d"
+checksum = "1e7ac75179f18232fe9c285163565a57ef8d3c89254a30685b57d83a38d326c2"
 
 [[package]]
 name = "windows_x86_64_gnu"
@@ -2490,9 +2522,9 @@ checksum = "147a5c80aabfbf0c7d901cb5895d1de30ef2907eb21fbbab29ca94c5b08b1a78"
 
 [[package]]
 name = "windows_x86_64_gnu"
-version = "0.53.0"
+version = "0.53.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2e55b5ac9ea33f2fc1716d1742db15574fd6fc8dadc51caab1c16a3d3b4190ba"
+checksum = "9c3842cdd74a865a8066ab39c8a7a473c0778a3f29370b5fd6b4b9aa7df4a499"
 
 [[package]]
 name = "windows_x86_64_gnullvm"
@@ -2502,9 +2534,9 @@ checksum = "24d5b23dc417412679681396f2b49f3de8c1473deb516bd34410872eff51ed0d"
 
 [[package]]
 name = "windows_x86_64_gnullvm"
-version = "0.53.0"
+version = "0.53.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0a6e035dd0599267ce1ee132e51c27dd29437f63325753051e71dd9e42406c57"
+checksum = "0ffa179e2d07eee8ad8f57493436566c7cc30ac536a3379fdf008f47f6bb7ae1"
 
 [[package]]
 name = "windows_x86_64_msvc"
@@ -2514,9 +2546,9 @@ checksum = "589f6da84c646204747d1270a2a5661ea66ed1cced2631d546fdfb155959f9ec"
 
 [[package]]
 name = "windows_x86_64_msvc"
-version = "0.53.0"
+version = "0.53.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "271414315aff87387382ec3d271b52d7ae78726f5d44ac98b4f4030c91880486"
+checksum = "d6bbff5f0aada427a1e5a6da5f1f98158182f26556f345ac9e04d36d0ebed650"
 
 [[package]]
 name = "winnow"
@@ -2529,15 +2561,15 @@ dependencies = [
 
 [[package]]
 name = "wit-bindgen"
-version = "0.45.0"
+version = "0.46.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "052283831dbae3d879dc7f51f3d92703a316ca49f91540417d38591826127814"
+checksum = "f17a85883d4e6d00e8a97c586de764dabcc06133f7f1d55dce5cdc070ad7fe59"
 
 [[package]]
 name = "xattr"
-version = "1.5.1"
+version = "1.6.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "af3a19837351dc82ba89f8a125e22a3c475f05aba604acc023d62b2739ae2909"
+checksum = "32e45ad4206f6d2479085147f02bc2ef834ac85886624a23575ae137c8aa8156"
 dependencies = [
  "libc",
  "rustix",
@@ -2554,18 +2586,18 @@ dependencies = [
 
 [[package]]
 name = "zerocopy"
-version = "0.8.26"
+version = "0.8.27"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1039dd0d3c310cf05de012d8a39ff557cb0d23087fd44cad61df08fc31907a2f"
+checksum = "0894878a5fa3edfd6da3f88c4805f4c8558e2b996227a3d864f47fe11e38282c"
 dependencies = [
  "zerocopy-derive",
 ]
 
 [[package]]
 name = "zerocopy-derive"
-version = "0.8.26"
+version = "0.8.27"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9ecf5b4cc5364572d7f4c329661bcc82724222973f2cab6f050a4e5c22f75181"
+checksum = "88d2b8d9c68ad2b9e4340d7832716a4d21a22a1154777ad56ea55c51a9cf3831"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -2574,15 +2606,15 @@ dependencies = [
 
 [[package]]
 name = "zeroize"
-version = "1.8.1"
+version = "1.8.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ced3678a2879b30306d323f4542626697a464a97c0a07c9aebf7ebca65cd4dde"
+checksum = "b97154e67e32c85465826e8bcc1c59429aaaf107c1e4a9e53c8d8ccd5eff88d0"
 
 [[package]]
 name = "zstd-sys"
-version = "2.0.15+zstd.1.5.7"
+version = "2.0.16+zstd.1.5.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "eb81183ddd97d0c74cedf1d50d85c8d08c1b8b68ee863bdee9e706eedba1a237"
+checksum = "91e19ebc2adc8f83e43039e79776e3fda8ca919132d68a1fed6a5faca2683748"
 dependencies = [
  "cc",
  "pkg-config",
diff --git a/Cargo.toml b/Cargo.toml
index f0ec792b..f9f6ff27 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,39 +1,30 @@
-[package]
-name = "d-engine"
-version = "0.1.4"
-edition = "2021"
-resolver = "2" # Workspace-level unified configuration
-authors = ["Joshua Chi <joshokn@gmail.com>"]
-categories = ["concurrency", "asynchronous", "algorithms", "database"]
-keywords = [
-    "raft",
-    "consensus",
-    "distributed-systems",
-    "storage",
-    "fault-tolerance",
+
+[workspace]
+members = [
+  "d-engine",
+  "d-engine-proto",
+  "d-engine-core",
+  "d-engine-client",
+  "d-engine-docs",
+  "d-engine-server"
 ]
-description = "A lightweight and strongly consistent Raft consensus engine written in Rust. It is a base to build reliable and scalable distributed systems."
-homepage = "https://github.com/deventlab/d-engine"
-license = "MIT OR Apache-2.0"
-repository = "https://github.com/deventlab/d-engine"
-
-[features]
-default = [] # Optional: Include "rocks" in default if desired
-rocksdb = [
-    "dep:rocksdb",
-] # Enable rocksdb dependency when "rocks" feature is active
-
-[dependencies]
-serde = { version = "1.0", default-features = false, features = ["derive"] }
-prost = { version = "0.13", default-features = false }
-bincode = "1.3"
-tonic = { version = "0.12.3", features = ["gzip", "tls"] }
-tonic-health = "0.12.3"
-# certification
-rcgen = { version = "0.13", features = ["pem"] }
-# compress
-flate2 = { version = "1.0", default-features = false, features = ["zlib"] }
-# Async
+
+exclude = [
+  "examples/client_usage",
+  "examples/rocksdb-cluster",
+  "examples/sled-cluster",
+  "examples/three-nodes-cluster",
+  "benches/d-engine-bench",
+]
+
+resolver = "2"
+
+[workspace.dependencies]
+d-engine-proto = { path = "./d-engine-proto" }
+d-engine-core = { path = "./d-engine-core" }
+d-engine-client = { path = "./d-engine-client" }
+d-engine-server = { path = "./d-engine-server" }
+
 tokio = { version = "1.4", features = [
     "macros",
     "time",
@@ -41,63 +32,93 @@ tokio = { version = "1.4", features = [
     "fs",
     "sync",
 ] }
-tokio-stream = "0.1.16"
-# use tokio_util::sync::CancellationToken;
-tokio-util = "0.7.11"
-
-futures = "0.3.30"
-rocksdb = { version = "0.24.0", optional = true }
-
-# Monitoring
-metrics = { version = "0.24", features = [] }
-# log
+serde = { version = "1.0", default-features = false, features = ["derive"] }
+prost = { version = "0.13", default-features = false }
+bincode = "1.3"
+tonic = { version = "0.12.3", features = ["gzip", "tls"] }
+tonic-health = "0.12.3"
+bytes =  { version = "1.10", features = ["serde"] }
 tracing = { version = "0.1.41" }
-parking_lot = "0.12.3"
+futures = "0.3.30"
 rand = "0.8.5"
-thiserror = "1.0"
-config = { version = "0.14.0", default-features = false, features = ["toml"] }
-nanoid = "0.4.0"
-# using Dashset
-dashmap = "5.5.3"
-arc-swap = "1.7.1"
-bytes =  { version = "1.10", features = ["serde"] }
 tempfile = "3.19.1"
-crc32fast = "1.4.2"
-sha2 = "0.10.9"
-async-stream = "0.3.6"
 
-# Compress/decompress data stream
-async-compression = { version = "0.4", features = ["tokio", "gzip"] }
+# [package]
+# name = "d-engine"
+# version = "0.1.4"
+# edition = "2021"
+# resolver = "2" # Workspace-level unified configuration
+# authors = ["Joshua Chi <joshokn@gmail.com>"]
+# categories = ["concurrency", "asynchronous", "algorithms", "database"]
+# keywords = [
+#     "raft",
+#     "consensus",
+#     "distributed-systems",
+#     "storage",
+#     "fault-tolerance",
+# ]
+# description = "A lightweight and strongly consistent Raft consensus engine written in Rust. It is a base to build reliable and scalable distributed systems."
+# homepage = "https://github.com/deventlab/d-engine"
+# license = "MIT OR Apache-2.0"
+# repository = "https://github.com/deventlab/d-engine"
+
+# [features]
+# default = [] # Optional: Include "rocks" in default if desired
+# rocksdb = [
+#     "dep:rocksdb",
+# ] # Enable rocksdb dependency when "rocks" feature is active
+
+# [dependencies]
+
+# compress
+# flate2 = { version = "1.0", default-features = false, features = ["zlib"] }
+# # Async
+
+
+#
+
 
-# Packing/unpacking TAR archives
-tokio-tar = "0.3"
-http-body = "1.0"
-http-body-util = "0.1.3"
-memmap2 = "0.9.5"
-lru = "0.15.0"
+# # Monitoring
+# metrics = { version = "0.24", features = [] }
+# # log
+# parking_lot = "0.12.3"
+#
+# thiserror = "1.0"
+# config = { version = "0.14.0", default-features = false, features = ["toml"] }
+# nanoid = "0.4.0"
+# # using Dashset
+# dashmap = "5.5.3"
+#
+# crc32fast = "1.4.2"
+# sha2 = "0.10.9"
+# async-stream = "0.3.6"
 
-# Cargo build performance optimization
-ring = { version = "=0.17.14", features = ["std"] }
+# # Compress/decompress data stream
+# async-compression = { version = "0.4", features = ["tokio", "gzip"] }
+
+
+# memmap2 = "0.9.5"
+
+# # Cargo build performance optimization
+# ring = { version = "=0.17.14", features = ["std"] }
 
 # TODO: to replace dashmap
-crossbeam-skiplist = "0.1"
-crossbeam = "0.8"
-
-[dev-dependencies]
-mockall = "0.12.1"
-tracing-subscriber = "0.3.20"
-once_cell = "1.20.2"
-tokio = { version = "1", features = ["test-util", "process"] }
-serial_test = "3.2.0"
-hyper = "1.6.0"
-temp-env = "0.3.6"
-nix = { version = "0.30.1", features = ["fs"] }
-tracing-test = "0.2"
-uuid = { version = "1", features = ["v4"] }
-
-[build-dependencies]
-tonic-build = "0.12"
-vergen = { version = "8.1", features = ["git", "gitcl"] }
+
+# [dev-dependencies]
+# mockall = "0.12.1"
+# tracing-subscriber = "0.3.20"
+# once_cell = "1.20.2"
+# tokio = { version = "1", features = ["test-util", "process"] }
+# serial_test = "3.2.0"
+# hyper = "1.6.0"
+# temp-env = "0.3.6"
+# nix = { version = "0.30.1", features = ["fs"] }
+# tracing-test = "0.2"
+# uuid = { version = "1", features = ["v4"] }
+
+# [build-dependencies]
+# tonic-build = "0.12"
+# vergen = { version = "8.1", features = ["git", "gitcl"] }
 
 [profile.dev]
 opt-level = 1      # Main code is low-optimized to speed up compilation
diff --git a/Makefile b/Makefile
index e6a90e97..9d47aed0 100644
--- a/Makefile
+++ b/Makefile
@@ -1,71 +1,549 @@
-# Release Management Makefile
-.PHONY: all pre-release check-env install clean help
+# ============================================================================
+# Makefile for d-engine Rust Workspace
+# ============================================================================
+# This Makefile provides convenient commands for managing a multi-crate
+# Rust workspace including: formatting, linting, testing, and release tasks.
+#
+# Usage: make <target>
+# Examples:
+#   make help              # Show all available targets
+#   make check             # Run all quality checks (fmt, clippy, test)
+#   make fmt-fix           # Fix all formatting issues automatically
+#   make clippy-fix        # Apply clippy suggestions automatically
+#   make test              # Run all tests with logging
+#   make pre-release       # Comprehensive pre-release validation
+#
+# ============================================================================
 
-# Configuration
-SCRIPT_PATH := scripts/pre-release-checklist.sh
-CARGO_TOOLCHAIN := 1.84.0  # Update to your toolchain
-CRATE_NAME := d_engine          # Update to your crate name
-RUST_LOG_LEVEL := d_engine=info
+.PHONY: help all check fmt fmt-check clippy clippy-fix test test-unit \
+        test-integration test-doc bench clean doc build build-release \
+        pre-release install check-env audit deny troubleshoot \
+        test-crate test-examples test-detailed \
+        docs docs-all docs-check docs-check-all
 
-## Show this help
+# ============================================================================
+# CONFIGURATION SECTION
+# ============================================================================
+
+# Cargo executable
+CARGO ?= cargo
+
+# Rust logging level for tests
+RUST_LOG_LEVEL ?= d_engine=debug
+
+# Backtrace level for debugging
+RUST_BACKTRACE ?= 1
+
+# Workspace member crates
+WORKSPACE_MEMBERS := d-engine-proto d-engine-core d-engine-client d-engine-server d-engine-docs
+
+# Color codes for formatted output
+RED := \033[0;31m
+GREEN := \033[0;32m
+YELLOW := \033[1;33m
+BLUE := \033[0;34m
+MAGENTA := \033[0;35m
+CYAN := \033[0;36m
+NC := \033[0m # No Color
+
+# ============================================================================
+# HELP TARGET - Display all available commands
+# ============================================================================
+
+## help                 Display this help message with all available targets
 help:
-	@awk 'BEGIN {FS = ":.*?## "} /^[a-zA-Z_-]+:.*?## / {printf "\033[36m%-15s\033[0m %s\n", $$1, $$2}' $(MAKEFILE_LIST)
-
-all: pre-release
-
-## Run all pre-release checks
-pre-release: check-env install ## Run all pre-release checks
-	@echo "\n\033[1;33m=== Starting Release Preparation ===\033[0m"
-	@$(SCRIPT_PATH) || (echo "\033[0;31mPre-release checks failed!\033[0m" && exit 1)
-	@echo "\n\033[1;32m✓ All checks passed. Ready for release!\033[0m"
-
-## Verify environment prerequisites
-check-env: ## Verify environment
-	@command -v cargo >/dev/null 2>&1 || \
-		(echo "\033[0;31mError: cargo not found!\033[0m" && exit 1)
-	@rustup toolchain list | grep -q $(CARGO_TOOLCHAIN) || \
-		(echo "\033[0;31mError: Required toolchain $(CARGO_TOOLCHAIN) missing!\033[0m" && exit 1)
-
-## Install prerequisites
-install: ## Install prerequisites
-	@chmod +x $(SCRIPT_PATH)
-	@rustup component add \
-		clippy \
-		rustfmt \
-		rust-docs
-
-## Clean build artifacts
-clean: ## Clean build artifacts
-	@cargo clean
+	@echo "$(BLUE)╔════════════════════════════════════════════════════════╗$(NC)"
+	@echo "$(BLUE)║  d-engine Workspace Build System                      ║$(NC)"
+	@echo "$(BLUE)╚════════════════════════════════════════════════════════╝$(NC)"
+	@echo ""
+	@echo "$(CYAN)Available Targets:$(NC)"
+	@awk 'BEGIN {FS = ":.*?## "} /^[a-zA-Z_-]+:.*?## / {printf "  $(GREEN)%-20s$(NC) %s\n", $$1, $$2}' $(MAKEFILE_LIST)
+	@echo ""
+	@echo "$(CYAN)Common Workflows:$(NC)"
+	@echo "  $(YELLOW)Development:$(NC)"
+	@echo "    make check          # Run all quality checks before committing"
+	@echo "    make fmt-fix        # Auto-fix formatting issues"
+	@echo "    make clippy-fix     # Apply clippy suggestions"
+	@echo ""
+	@echo "  $(YELLOW)Documentation:$(NC)"
+	@echo "    make docs           # Build and open documentation in browser"
+	@echo "    make docs-check     # Verify docs compile without warnings"
+	@echo "    make docs-private   # Build docs with private items visible"
+	@echo "    make docs-crate CRATE=name  # Build docs for specific crate"
+	@echo ""
+	@echo "  $(YELLOW)Testing:$(NC)"
+	@echo "    make test           # Run unit + integration tests"
+	@echo "    make test-detailed  # Run tests with detailed failure output"
+	@echo "    make test-all       # Run all tests including benchmarks"
+	@echo "    make test-unit      # Run unit tests only"
+	@echo ""
+	@echo "  $(YELLOW)Release:$(NC)"
+	@echo "    make pre-release    # Full pre-release validation"
+	@echo "    make build-release  # Build release artifacts"
+	@echo ""
+	@echo "  $(YELLOW)Maintenance:$(NC)"
+	@echo "    make clean          # Remove all build artifacts"
+	@echo "    make docs-clean     # Remove generated documentation"
+	@echo "    make audit          # Check for security vulnerabilities"
+	@echo "    make troubleshoot   # Diagnostic information"
+	@echo ""
+
+# ============================================================================
+# ENVIRONMENT VERIFICATION
+# ============================================================================
+
+## check-env            Verify Rust environment prerequisites are installed
+check-env:
+	@echo "$(BLUE)Verifying Rust environment...$(NC)"
+	@command -v $(CARGO) >/dev/null 2>&1 || \
+		{ echo "$(RED)✗ Error: cargo not found in PATH$(NC)"; exit 1; }
+	@command -v rustc >/dev/null 2>&1 || \
+		{ echo "$(RED)✗ Error: rustc not found in PATH$(NC)"; exit 1; }
+	@command -v rustup >/dev/null 2>&1 || \
+		{ echo "$(RED)✗ Error: rustup not found in PATH$(NC)"; exit 1; }
+	@echo "$(GREEN)✓ Cargo found: $$($(CARGO) --version)$(NC)"
+	@echo "$(GREEN)✓ Rustc found: $$(rustc --version)$(NC)"
+
+## install-tools        Install required Rust components (rustfmt, clippy, etc.)
+install-tools: check-env
+	@echo "$(BLUE)Installing Rust development components...$(NC)"
+	@rustup component add rustfmt clippy rust-src rust-analyzer 2>/dev/null || true
+	@echo "$(GREEN)✓ Components installed$(NC)"
+	@echo "$(CYAN)Optional: cargo install cargo-nextest --locked$(NC)"
+
+## install              Alias for install-tools
+install: install-tools
+
+# ============================================================================
+# WORKSPACE VALIDATION
+# ============================================================================
+
+## check-workspace      Verify all workspace crates are properly configured
+check-workspace: check-env
+	@echo "$(BLUE)Validating workspace structure...$(NC)"
+	@for member in $(WORKSPACE_MEMBERS); do \
+		if [ ! -f "$$member/Cargo.toml" ]; then \
+			echo "$(RED)✗ Missing Cargo.toml in $$member$(NC)"; \
+			exit 1; \
+		fi; \
+		echo "$(GREEN)✓ $$member/Cargo.toml found$(NC)"; \
+	done
+	@echo "$(GREEN)✓ Workspace structure validated$(NC)"
+
+# ============================================================================
+# CODE QUALITY - FORMATTING
+# ============================================================================
+
+## fmt-check            Check code formatting without modifying files (dry-run)
+fmt-check: check-workspace
+	@echo "$(BLUE)Checking code formatting...$(NC)"
+	@$(CARGO) fmt --all -- --check || \
+		{ echo "$(RED)✗ Formatting issues found. Run 'make fmt-fix' to fix them.$(NC)"; exit 1; }
+	@echo "$(GREEN)✓ Code formatting check passed$(NC)"
+
+## fmt fmt-fix          Fix all code formatting issues automatically
+fmt fmt-fix: install-tools check-workspace
+	@echo "$(BLUE)Applying code formatting fixes...$(NC)"
+	@$(CARGO) fmt --all
+	@echo "$(GREEN)✓ Code formatting fixed in all crates$(NC)"
+
+# ============================================================================
+# CODE QUALITY - LINTING (CLIPPY)
+# ============================================================================
+
+## clippy               Run Clippy linter (fail on warnings with -D flag)
+clippy: check-workspace
+	@echo "$(BLUE)Running Clippy linter on all crates...$(NC)"
+	@$(CARGO) clippy --workspace --all-targets --all-features -- -D warnings || \
+		{ echo "$(RED)✗ Clippy warnings found. Run 'make clippy-fix' for suggestions.$(NC)"; exit 1; }
+	@echo "$(GREEN)✓ Clippy lint check passed$(NC)"
+
+## clippy-fix           Automatically apply Clippy suggestions (review changes!)
+clippy-fix: install-tools check-workspace
+	@echo "$(BLUE)Applying Clippy suggestions...$(NC)"
+	@$(CARGO) clippy --workspace --all-targets --all-features --fix \
+		--allow-no-vcs --allow-dirty --allow-staged
+	@echo "$(YELLOW)Re-checking for remaining issues...$(NC)"
+	@$(CARGO) clippy --workspace --all-targets --all-features -- -D warnings || \
+		{ echo "$(YELLOW)Note: Some warnings require manual review and fixes$(NC)"; }
+	@echo "$(GREEN)✓ Clippy fixes applied$(NC)"
+	@echo "$(MAGENTA)IMPORTANT: Review changes before committing!$(NC)"
+
+# ============================================================================
+# CODE QUALITY - COMPREHENSIVE CHECKS
+# ============================================================================
+
+## check                Run all quality checks (fmt, clippy, cargo check)
+check: fmt-check clippy
+	@echo ""
+	@echo "$(GREEN)╔════════════════════════════════════════╗$(NC)"
+	@echo "$(GREEN)║  ✓ All code quality checks passed!    ║$(NC)"
+	@echo "$(GREEN)╚════════════════════════════════════════╝$(NC)"
+
+## quick-check          Fast validation (cargo check + fmt-check only)
+quick-check: check-workspace
+	@echo "$(BLUE)Running quick validation...$(NC)"
+	@$(CARGO) check --workspace --all-targets --all-features
+	@$(CARGO) fmt --all -- --check || exit 1
+	@echo "$(GREEN)✓ Quick validation passed$(NC)"
+
+# ============================================================================
+# BUILD TARGETS
+# ============================================================================
+
+## build                Build all workspace crates in debug mode
+build: check-workspace
+	@echo "$(BLUE)Building workspace (debug mode)...$(NC)"
+	@$(CARGO) build --workspace --all-targets --all-features
+	@echo "$(GREEN)✓ Debug build completed$(NC)"
+
+## build-release        Build all workspace crates in release mode (optimized)
+build-release: check check-workspace
+	@echo "$(BLUE)Building workspace (release mode, optimized)...$(NC)"
+	@$(CARGO) build --workspace --all-features --release
+	@echo "$(GREEN)✓ Release build completed$(NC)"
+	@echo "$(CYAN)Release artifacts: target/release/$(NC)"
+
+# ============================================================================
+# TESTING
+# ============================================================================
+
+## test                 Run all tests (lib + bins + examples + integration)
+test: install-tools check-workspace
+	@echo "$(BLUE)Running tests on all targets...$(NC)"
+	@RUST_LOG=$(RUST_LOG_LEVEL) RUST_BACKTRACE=$(RUST_BACKTRACE) \
+		$(CARGO) test --workspace --all-targets --no-fail-fast -- --test-threads=1 --nocapture
+	@echo "$(GREEN)✓ All tests passed$(NC)"
+
+## test-detailed        Run tests with detailed failure output for each crate
+test-detailed: install-tools check-workspace
+	@echo "$(BLUE)Running tests with detailed output per crate...$(NC)"
+	@for member in $(WORKSPACE_MEMBERS); do \
+		echo "$(CYAN)Testing crate: $$member$(NC)"; \
+		RUST_LOG=$(RUST_LOG_LEVEL) RUST_BACKTRACE=$(RUST_BACKTRACE) \
+		$(CARGO) test -p $$member --all-targets --no-fail-fast -- --test-threads=1 --nocapture || \
+		{ echo "$(RED)✗ Tests failed in crate: $$member$(NC)"; exit 1; }; \
+		echo "$(GREEN)✓ Tests passed for crate: $$member$(NC)"; \
+		echo ""; \
+	done
+	@echo "$(BLUE)Running examples tests...$(NC)"
+	@RUST_LOG=$(RUST_LOG_LEVEL) RUST_BACKTRACE=$(RUST_BACKTRACE) \
+		$(CARGO) test --workspace --examples --no-fail-fast -- --test-threads=1 --nocapture || \
+		{ echo "$(RED)✗ Examples tests failed$(NC)"; exit 1; }
+	@echo "$(GREEN)✓ All examples tests passed$(NC)"
+	@echo "$(GREEN)✓ All tests passed with detailed output$(NC)"
+
+## test-unit            Run unit tests only (library code only)
+test-unit: install-tools check-workspace
+	@echo "$(BLUE)Running unit tests (lib only)...$(NC)"
+	@RUST_LOG=$(RUST_LOG_LEVEL) RUST_BACKTRACE=$(RUST_BACKTRACE) \
+		$(CARGO) test --workspace --lib --no-fail-fast -- --nocapture
+	@echo "$(GREEN)✓ Unit tests passed$(NC)"
+
+## test-integration     Run integration tests only (--test flag)
+test-integration: install-tools check-workspace
+	@echo "$(BLUE)Running integration tests...$(NC)"
+	@RUST_LOG=$(RUST_LOG_LEVEL) RUST_BACKTRACE=$(RUST_BACKTRACE) \
+		$(CARGO) test --workspace --tests --no-fail-fast -- --nocapture
+	@echo "$(GREEN)✓ Integration tests passed$(NC)"
+
+## test-doc             Run documentation tests only
+test-doc: install-tools check-workspace
+	@echo "$(BLUE)Running documentation tests...$(NC)"
+	@$(CARGO) test --doc --workspace
+	@echo "$(GREEN)✓ Documentation tests passed$(NC)"
+
+## test-examples        Run tests for examples only
+test-examples: install-tools check-workspace
+	@echo "$(BLUE)Running examples tests...$(NC)"
+	@RUST_LOG=$(RUST_LOG_LEVEL) RUST_BACKTRACE=$(RUST_BACKTRACE) \
+		$(CARGO) test --workspace --examples --no-fail-fast -- --test-threads=1 --nocapture
+	@echo "$(GREEN)✓ Examples tests passed$(NC)"
+
+## test-crate           Run tests for a specific crate (usage: make test-crate CRATE=d-engine)
+test-crate: install-tools check-workspace
+ifndef CRATE
+	@echo "$(RED)Error: CRATE variable not set. Usage: make test-crate CRATE=crate-name$(NC)"
+	@exit 1
+endif
+	@echo "$(BLUE)Running tests for crate: $(CRATE)$(NC)"
+	@RUST_LOG=$(RUST_LOG_LEVEL) RUST_BACKTRACE=$(RUST_BACKTRACE) \
+		$(CARGO) test -p $(CRATE) --all-targets --no-fail-fast -- --test-threads=1 --nocapture --show-output
+	@echo "$(GREEN)✓ All tests passed for crate: $(CRATE)$(NC)"
+
+## test-all             Run all tests: unit + integration + doc + benchmarks
+test-all: test-detailed test-doc bench
+	@echo "$(GREEN)✓ All test suites passed$(NC)"
+
+## test-verbose         Run tests with verbose output and single-threaded execution
+test-verbose: install-tools check-workspace
+	@echo "$(BLUE)Running tests (verbose, single-threaded)...$(NC)"
+	@RUST_LOG=$(RUST_LOG_LEVEL) RUST_BACKTRACE=$(RUST_BACKTRACE) \
+		$(CARGO) test --workspace --all-targets --no-fail-fast -- --nocapture --test-threads=1 --show-output
+	@echo "$(GREEN)✓ Verbose test run completed$(NC)"
+
+# ============================================================================
+# PERFORMANCE & BENCHMARKING
+# ============================================================================
+
+## bench                Run performance benchmarks (if configured)
+bench: check-workspace
+	@echo "$(BLUE)Running performance benchmarks...$(NC)"
+	@$(CARGO) bench --workspace --all-features --no-fail-fast -- --nocapture || \
+		{ echo "$(YELLOW)Note: No benchmarks configured or not supported in this workspace$(NC)"; }
+	@echo "$(GREEN)✓ Benchmark run completed$(NC)"
+
+# ============================================================================
+# DOCUMENTATION
+# ============================================================================
+
+## docs                Generate API documentation and open in browser (opens d-engine-docs hub)
+docs: check-workspace
+	@echo "$(BLUE)Generating API documentation for all workspace crates...$(NC)"
+	@$(CARGO) doc --workspace --no-deps
+	@echo "$(GREEN)✓ Documentation generated$(NC)"
+	@echo "$(CYAN)Opening documentation hub at: target/doc/d_engine_docs/index.html$(NC)"
+	@open "file://$$(pwd)/target/doc/d_engine_docs/index.html" 2>/dev/null || xdg-open "file://$$(pwd)/target/doc/d_engine_docs/index.html" 2>/dev/null || echo "Please open: target/doc/d_engine_docs/index.html"
+
+## docs-all             Generate documentation with all features enabled
+docs-all: check-workspace
+	@echo "$(BLUE)Generating API documentation (all features)...$(NC)"
+	@$(CARGO) doc --workspace --all-features --no-deps
+	@echo "$(GREEN)✓ Documentation generated$(NC)"
+	@echo "$(CYAN)Opening documentation hub at: target/doc/d_engine_docs/index.html$(NC)"
+	@open "file://$$(pwd)/target/doc/d_engine_docs/index.html" 2>/dev/null || xdg-open "file://$$(pwd)/target/doc/d_engine_docs/index.html" 2>/dev/null || echo "Please open: target/doc/d_engine_docs/index.html"
+
+## docs-check           Check documentation without opening browser (CI-safe)
+docs-check: check-workspace
+	@echo "$(BLUE)Checking documentation generation...$(NC)"
+	@RUSTDOCFLAGS="-D warnings" $(CARGO) doc --workspace --no-deps
+	@echo "$(GREEN)✓ Documentation compiled without warnings$(NC)"
+
+## docs-check-all       Check documentation with all features and strict warnings
+docs-check-all: check-workspace
+	@echo "$(BLUE)Checking documentation (all features, strict mode)...$(NC)"
+	@RUSTDOCFLAGS="-D warnings" $(CARGO) doc --workspace --all-features --no-deps
+	@echo "$(GREEN)✓ Documentation compiled without warnings$(NC)"
+
+## docs-private         Generate documentation including private items (architecture)
+docs-private: check-workspace
+	@echo "$(BLUE)Generating documentation with private items...$(NC)"
+	@$(CARGO) doc --workspace --no-deps --document-private-items
+	@echo "$(GREEN)✓ Documentation generated$(NC)"
+	@echo "$(CYAN)Opening documentation hub at: target/doc/d_engine_docs/index.html$(NC)"
+	@open "file://$$(pwd)/target/doc/d_engine_docs/index.html" 2>/dev/null || xdg-open "file://$$(pwd)/target/doc/d_engine_docs/index.html" 2>/dev/null || echo "Please open: target/doc/d_engine_docs/index.html"
+
+## docs-crate           Generate documentation for a single crate (usage: make docs-crate CRATE=d-engine-server)
+docs-crate: check-workspace
+ifndef CRATE
+	@echo "$(RED)Error: CRATE variable not set. Usage: make docs-crate CRATE=crate-name$(NC)"
+	@exit 1
+endif
+	@echo "$(BLUE)Generating documentation for crate: $(CRATE)...$(NC)"
+	@$(CARGO) doc -p $(CRATE) --no-deps
+	@echo "$(GREEN)✓ Documentation generated$(NC)"
+	@echo "$(CYAN)Opening crate documentation at: target/doc/$$(echo $(CRATE) | sed 's/-/_/g')/index.html$(NC)"
+	@open "file://$$(pwd)/target/doc/$$(echo $(CRATE) | sed 's/-/_/g')/index.html" 2>/dev/null || xdg-open "file://$$(pwd)/target/doc/$$(echo $(CRATE) | sed 's/-/_/g')/index.html" 2>/dev/null || echo "Please open: target/doc/$$(echo $(CRATE) | sed 's/-/_/g')/index.html"
+
+## docs-clean           Remove generated documentation artifacts
+docs-clean:
+	@echo "$(BLUE)Cleaning documentation artifacts...$(NC)"
+	@rm -rf target/doc
+	@echo "$(GREEN)✓ Documentation cleaned$(NC)"
+
+## doc                  (Deprecated alias) Use 'docs' instead
+doc: docs
+
+## doc-check            (Deprecated alias) Use 'docs-check' instead
+doc-check: docs-check
+
+# ============================================================================
+# SECURITY & DEPENDENCY AUDITING
+# ============================================================================
+
+## audit                Audit dependencies for known security vulnerabilities
+audit: check-env
+	@echo "$(BLUE)Auditing dependencies for vulnerabilities...$(NC)"
+	@if command -v cargo-audit >/dev/null 2>&1; then \
+		cargo audit; \
+	else \
+		echo "$(YELLOW)Note: cargo-audit not installed. Install with: cargo install cargo-audit$(NC)"; \
+	fi
+
+## deny                 Run cargo deny for supply chain security checks
+deny: check-env
+	@echo "$(BLUE)Running cargo deny checks...$(NC)"
+	@if command -v cargo-deny >/dev/null 2>&1; then \
+		cargo deny check; \
+	else \
+		echo "$(YELLOW)Note: cargo-deny not installed. Install with: cargo install cargo-deny$(NC)"; \
+	fi
+
+# ============================================================================
+# CLEANUP & MAINTENANCE
+# ============================================================================
+
+## clean                Remove all build artifacts and cache files
+clean:
+	@echo "$(BLUE)Cleaning build artifacts...$(NC)"
+	@$(CARGO) clean
 	@rm -rf target/ coverage/ *.log
+	@echo "$(GREEN)✓ Cleanup completed$(NC)"
+
+## clean-deps           Aggressive cleanup: remove artifacts, cache, and Cargo.lock
+clean-deps: clean
+	@echo "$(BLUE)Aggressive dependency cleanup...$(NC)"
+	@rm -f Cargo.lock
+	@echo "$(YELLOW)Updating Rust toolchain...$(NC)"
+	@rustup self update
+	@echo "$(GREEN)✓ Deep cleanup completed$(NC)"
+
+# ============================================================================
+# DIAGNOSTIC & TROUBLESHOOTING
+# ============================================================================
+
+## troubleshoot         Display diagnostic information for debugging build issues
+troubleshoot: check-env
+	@echo "$(MAGENTA)═══════════════════════════════════════════════════════$(NC)"
+	@echo "$(MAGENTA)  DIAGNOSTIC INFORMATION FOR TROUBLESHOOTING$(NC)"
+	@echo "$(MAGENTA)═══════════════════════════════════════════════════════$(NC)"
+	@echo ""
+	@echo "$(CYAN)1. Rust Environment:$(NC)"
+	@echo "   Rustc version:"
+	@rustc --version
+	@echo "   Cargo version:"
+	@$(CARGO) --version
+	@echo "   Toolchain info:"
+	@rustup show
+	@echo ""
+	@echo "$(CYAN)2. Workspace Metadata:$(NC)"
+	@$(CARGO) metadata --format-version=1 | grep -E '"name"|"version"' | head -20
+	@echo ""
+	@echo "$(CYAN)3. Workspace Members:$(NC)"
+	@for member in $(WORKSPACE_MEMBERS); do \
+		if [ -f "$$member/Cargo.toml" ]; then \
+			echo "   ✓ $$member"; \
+		else \
+			echo "   ✗ $$member (missing)"; \
+		fi; \
+	done
+	@echo ""
+	@echo "$(CYAN)4. Disk Usage:$(NC)"
+	@du -sh target/ 2>/dev/null || echo "   target/ not found"
+	@du -sh . | tail -1 || echo "   Unable to calculate"
+	@echo ""
+	@echo "$(CYAN)5. Common Issues & Fixes:$(NC)"
+	@echo "   • Compilation slow: Try 'make clean' and rebuild"
+	@echo "   • Tests timeout: Check 'make test-verbose' output"
+	@echo "   • Clippy errors: Run 'make clippy-fix' for automatic fixes"
+	@echo "   • Format issues: Run 'make fmt-fix' to auto-format"
+	@echo ""
+
+# ============================================================================
+# COMPOSITE WORKFLOWS
+# ============================================================================
+
+## pre-release          Full pre-release validation (comprehensive checks)
+pre-release: install-tools check-workspace check test-all audit build-release
+	@echo ""
+	@echo "$(GREEN)╔═══════════════════════════════════════════════════════╗$(NC)"
+	@echo "$(GREEN)║  ✓ ALL PRE-RELEASE CHECKS PASSED SUCCESSFULLY!       ║$(NC)"
+	@echo "$(GREEN)╚═══════════════════════════════════════════════════════╝$(NC)"
+	@echo ""
+	@echo "$(MAGENTA)Next Steps:$(NC)"
+	@echo "  1. Review CHANGELOG.md for accuracy"
+	@echo "  2. Update version numbers in all Cargo.toml files"
+	@echo "  3. Create annotated git tag: git tag -a v<VERSION>"
+	@echo "  4. Push to repository: git push && git push --tags"
+	@echo ""
+
+## fix                  Run automatic fixes (fmt-fix + clippy-fix)
+fix: fmt-fix clippy-fix
+	@echo ""
+	@echo "$(GREEN)✓ Automatic fixes completed$(NC)"
+	@echo "$(MAGENTA)IMPORTANT: Review and test your changes before committing!$(NC)"
+
+## all                  Default target: run full check suite
+all: check
+	@echo "$(GREEN)✓ Check suite completed$(NC)"
+
+# ============================================================================
+# EXAMPLES AND BENCHMARKS VALIDATION
+# ============================================================================
 
-# Benchmark Targets (Optional)
-bench: ## Run performance benchmarks
-	@cargo bench --features unstable
+## check-examples       Check all examples compile without errors
+check-examples:
+	@echo "$(CYAN)Checking all examples...$(NC)"
+	@for example in examples/*/; do \
+		if [ -f "$$example/Cargo.toml" ]; then \
+			example_name=$$(basename "$$example"); \
+			echo "$(YELLOW)→ Checking example: $$example_name$(NC)"; \
+			(cd "$$example" && $(CARGO) check 2>&1) || { \
+				echo "$(RED)✗ Example $$example_name failed$(NC)"; \
+				exit 1; \
+			}; \
+			echo "$(GREEN)✓ Example $$example_name OK$(NC)"; \
+		fi \
+	done
+	@echo "$(GREEN)✓ All examples checked successfully$(NC)"
 
-# Documentation Targets
-doc: ## Generate documentation
-	@cargo doc --all-features --no-deps --open
+## check-benches        Check all benchmarks compile without errors
+check-benches:
+	@echo "$(CYAN)Checking all benchmarks...$(NC)"
+	@for bench in benches/*/; do \
+		if [ -f "$$bench/Cargo.toml" ]; then \
+			bench_name=$$(basename "$$bench"); \
+			echo "$(YELLOW)→ Checking benchmark: $$bench_name$(NC)"; \
+			(cd "$$bench" && $(CARGO) check 2>&1) || { \
+				echo "$(RED)✗ Benchmark $$bench_name failed$(NC)"; \
+				exit 1; \
+			}; \
+			echo "$(GREEN)✓ Benchmark $$bench_name OK$(NC)"; \
+		fi \
+	done
+	@echo "$(GREEN)✓ All benchmarks checked successfully$(NC)"
 
-# Format Verification
-fmt-check: ## Check formatting
-	@cargo fmt --all -- --check
+## check-all-projects   Check workspace + examples + benchmarks
+check-all-projects: check check-examples check-benches
+	@echo ""
+	@echo "$(GREEN)════════════════════════════════════════$(NC)"
+	@echo "$(GREEN)✓ ALL PROJECTS VALIDATED SUCCESSFULLY$(NC)"
+	@echo "$(GREEN)════════════════════════════════════════$(NC)"
 
-# Format Verification
-fmt-fix: ## Check formatting
-	@cargo fmt --all
+## build-examples       Build all examples
+build-examples:
+	@echo "$(CYAN)Building all examples...$(NC)"
+	@for example in examples/*/; do \
+		if [ -f "$$example/Cargo.toml" ]; then \
+			example_name=$$(basename "$$example"); \
+			echo "$(YELLOW)→ Building example: $$example_name$(NC)"; \
+			(cd "$$example" && $(CARGO) build 2>&1) || { \
+				echo "$(RED)✗ Example $$example_name failed$(NC)"; \
+				exit 1; \
+			}; \
+			echo "$(GREEN)✓ Example $$example_name built$(NC)"; \
+		fi \
+	done
+	@echo "$(GREEN)✓ All examples built successfully$(NC)"
 
-# Run Clippy
-clippy: ## Run Clippy
-	@cargo clippy --all-targets --all-features -- -D warnings
+## test-examples        Run tests in all examples
+test-examples:
+	@echo "$(CYAN)Testing all examples...$(NC)"
+	@for example in examples/*/; do \
+		if [ -f "$$example/Cargo.toml" ]; then \
+			example_name=$$(basename "$$example"); \
+			echo "$(YELLOW)→ Testing example: $$example_name$(NC)"; \
+			(cd "$$example" && $(CARGO) test 2>&1) || { \
+				echo "$(RED)✗ Example $$example_name tests failed$(NC)"; \
+				exit 1; \
+			}; \
+			echo "$(GREEN)✓ Example $$example_name tests passed$(NC)"; \
+		fi \
+	done
+	@echo "$(GREEN)✓ All example tests passed$(NC)"
 
-# Run Clippy fix
-clippy-fix: ## Run Clippy fix
-	@cargo clippy --fix
+# ============================================================================
+# DEFAULT TARGET
+# ============================================================================
 
-# Test suite
-test: ## Run test suite
-	@RUST_LOG=$(RUST_LOG_LEVEL) cargo nextest run --no-fail-fast --tests --nocapture
-	@RUST_LOG=$(RUST_LOG_LEVEL) cargo nextest run --no-fail-fast --lib --nocapture
-	@RUST_LOG=$(RUST_LOG_LEVEL) cargo test --doc
-	@RUST_LOG=$(RUST_LOG_LEVEL) cargo bench -- --nocapture
+.DEFAULT_GOAL := help
diff --git a/README.md b/README.md
index 560c9f87..f99cea0d 100644
--- a/README.md
+++ b/README.md
@@ -41,7 +41,7 @@ d-engine = { version = "0.1.4", features = ["rocksdb"] }
 use d-engine::{RaftCore, MemoryStorage, Config};
 
 ```rust
-use d_engine::{NodeBuilder, FileStorageEngine, FileStateMachine};
+use d_engine_server::{NodeBuilder, FileStorageEngine, FileStateMachine};
 use tokio::sync::watch;
 use std::sync::Arc;
 use std::path::PathBuf;
diff --git a/benches/d-engine-bench/Cargo.lock b/benches/d-engine-bench/Cargo.lock
index 83c3d158..65c5b84d 100644
--- a/benches/d-engine-bench/Cargo.lock
+++ b/benches/d-engine-bench/Cargo.lock
@@ -2,48 +2,21 @@
 # It is not intended for manual editing.
 version = 4
 
-[[package]]
-name = "addr2line"
-version = "0.25.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1b5d307320b3181d6d7954e663bd7c774a838b8220fe0593c86d9fb09f498b4b"
-dependencies = [
- "gimli",
-]
-
 [[package]]
 name = "adler2"
 version = "2.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "320119579fcad9c21884f5c4861d16174d0e06250625266f50fe6898340abefa"
 
-[[package]]
-name = "ahash"
-version = "0.8.12"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5a15f179cd60c4584b8a8c596927aadc462e27f2ca70c04e0071964a73ba7a75"
-dependencies = [
- "cfg-if",
- "once_cell",
- "version_check",
- "zerocopy",
-]
-
 [[package]]
 name = "aho-corasick"
-version = "1.1.3"
+version = "1.1.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8e60d3430d3a69478ad0993f19238d2df97c507009a52b3c10addcd7f6bcb916"
+checksum = "ddd31a130427c27518df266943a5308ed92d4b226cc639f5a8f1002816174301"
 dependencies = [
  "memchr",
 ]
 
-[[package]]
-name = "allocator-api2"
-version = "0.2.21"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "683d7910e743518b0e34f1186f92494becacb047c7b6bf616c96772180fef923"
-
 [[package]]
 name = "anstream"
 version = "0.6.21"
@@ -106,19 +79,6 @@ version = "1.7.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "69f7f8c3906b62b754cd5326047894316021dcfe5a194c8ea52bdd94934a3457"
 
-[[package]]
-name = "async-compression"
-version = "0.4.32"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5a89bce6054c720275ac2432fbba080a66a2106a44a1b804553930ca6909f4e0"
-dependencies = [
- "compression-codecs",
- "compression-core",
- "futures-core",
- "pin-project-lite",
- "tokio",
-]
-
 [[package]]
 name = "async-stream"
 version = "0.3.6"
@@ -220,21 +180,6 @@ dependencies = [
  "tower-service",
 ]
 
-[[package]]
-name = "backtrace"
-version = "0.3.76"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bb531853791a215d7c62a30daf0dde835f381ab5de4589cfe7c649d2cbe92bd6"
-dependencies = [
- "addr2line",
- "cfg-if",
- "libc",
- "miniz_oxide",
- "object",
- "rustc-demangle",
- "windows-link",
-]
-
 [[package]]
 name = "base64"
 version = "0.21.7"
@@ -247,35 +192,11 @@ version = "0.22.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "72b3254f16251a8381aa12e40e3c4d2f0199f8c6508fbecb9d91f575e0fbb8c6"
 
-[[package]]
-name = "bincode"
-version = "1.3.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b1f45e9417d87227c7a56d22e471c6206462cba514c7590c09aff4cf6d1ddcad"
-dependencies = [
- "serde",
-]
-
 [[package]]
 name = "bitflags"
-version = "1.3.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"
-
-[[package]]
-name = "bitflags"
-version = "2.9.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2261d10cca569e4643e526d8dc2e62e433cc8aba21ab764233731f8d369bf394"
-
-[[package]]
-name = "block-buffer"
-version = "0.10.4"
+version = "2.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3078c7629b62d3f0439517fa394996acacc5cbc91c5a20d8c658e77abd503a71"
-dependencies = [
- "generic-array",
-]
+checksum = "812e12b5285cc515a9c72a5c1d3b6d46a19dac5acfef5265968c166106e31dd3"
 
 [[package]]
 name = "byteorder"
@@ -294,9 +215,9 @@ dependencies = [
 
 [[package]]
 name = "cc"
-version = "1.2.41"
+version = "1.2.44"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ac9fe6cdbb24b6ade63616c0a0688e45bb56732262c158df3c0c4bea4ca47cb7"
+checksum = "37521ac7aabe3d13122dc382493e20c9416f299d2ccd5b3a5340a2570cdeb0f3"
 dependencies = [
  "find-msvc-tools",
  "shlex",
@@ -304,15 +225,15 @@ dependencies = [
 
 [[package]]
 name = "cfg-if"
-version = "1.0.3"
+version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2fd1289c04a9ea8cb22300a459a72a385d7c73d3259e2ed7dcb2af674838cfa9"
+checksum = "9330f8b2ff13f34540b44e946ef35111825727b38d33286ef986142615121801"
 
 [[package]]
 name = "clap"
-version = "4.5.48"
+version = "4.5.51"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e2134bb3ea021b78629caa971416385309e0131b351b25e01dc16fb54e1b5fae"
+checksum = "4c26d721170e0295f191a69bd9a1f93efcdb0aff38684b61ab5750468972e5f5"
 dependencies = [
  "clap_builder",
  "clap_derive",
@@ -320,9 +241,9 @@ dependencies = [
 
 [[package]]
 name = "clap_builder"
-version = "4.5.48"
+version = "4.5.51"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c2ba64afa3c0a6df7fa517765e31314e983f51dda798ffba27b988194fb65dc9"
+checksum = "75835f0c7bf681bfd05abe44e965760fea999a5286c6eb2d59883634fd02011a"
 dependencies = [
  "anstream",
  "anstyle",
@@ -332,9 +253,9 @@ dependencies = [
 
 [[package]]
 name = "clap_derive"
-version = "4.5.47"
+version = "4.5.49"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bbfd7eae0b0f1a6e63d4b13c9c478de77c2eb546fba158ad50b4203dc24b9f9c"
+checksum = "2a0b5487afeab2deb2ff4e03a807ad1a03ac532ff5a2cee5d86884440c7f7671"
 dependencies = [
  "heck",
  "proc-macro2",
@@ -344,9 +265,9 @@ dependencies = [
 
 [[package]]
 name = "clap_lex"
-version = "0.7.5"
+version = "0.7.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b94f61472cee1439c0b966b47e3aca9ae07e45d070759512cd390ea2bebc6675"
+checksum = "a1d728cc89cf3aee9ff92b05e62b19ee65a02b5702cff7d5a377e32c6ae29d8d"
 
 [[package]]
 name = "colorchoice"
@@ -354,44 +275,6 @@ version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b05b61dc5112cbb17e4b6cd61790d9845d13888356391624cbe7e41efeac1e75"
 
-[[package]]
-name = "compression-codecs"
-version = "0.4.31"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ef8a506ec4b81c460798f572caead636d57d3d7e940f998160f52bd254bf2d23"
-dependencies = [
- "compression-core",
- "flate2",
- "memchr",
-]
-
-[[package]]
-name = "compression-core"
-version = "0.4.29"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e47641d3deaf41fb1538ac1f54735925e275eaf3bf4d55c81b137fba797e5cbb"
-
-[[package]]
-name = "config"
-version = "0.14.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "68578f196d2a33ff61b27fae256c3164f65e36382648e30666dde05b8cc9dfdf"
-dependencies = [
- "nom",
- "pathdiff",
- "serde",
- "toml",
-]
-
-[[package]]
-name = "cpufeatures"
-version = "0.2.17"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "59ed5838eebb26a2bb2e58f6d5b5316989ae9d08bab10e0e6d103e656d1b0280"
-dependencies = [
- "libc",
-]
-
 [[package]]
 name = "crc32fast"
 version = "1.5.0"
@@ -401,19 +284,6 @@ dependencies = [
  "cfg-if",
 ]
 
-[[package]]
-name = "crossbeam"
-version = "0.8.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1137cd7e7fc0fb5d3c5a8678be38ec56e819125d8d7907411fe24ccb943faca8"
-dependencies = [
- "crossbeam-channel",
- "crossbeam-deque",
- "crossbeam-epoch",
- "crossbeam-queue",
- "crossbeam-utils",
-]
-
 [[package]]
 name = "crossbeam-channel"
 version = "0.5.15"
@@ -423,105 +293,22 @@ dependencies = [
  "crossbeam-utils",
 ]
 
-[[package]]
-name = "crossbeam-deque"
-version = "0.8.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9dd111b7b7f7d55b72c0a6ae361660ee5853c9af73f70c3c2ef6858b950e2e51"
-dependencies = [
- "crossbeam-epoch",
- "crossbeam-utils",
-]
-
-[[package]]
-name = "crossbeam-epoch"
-version = "0.9.18"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5b82ac4a3c2ca9c3460964f020e1402edd5753411d7737aa39c3714ad1b5420e"
-dependencies = [
- "crossbeam-utils",
-]
-
-[[package]]
-name = "crossbeam-queue"
-version = "0.3.12"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0f58bbc28f91df819d0aa2a2c00cd19754769c2fad90579b3592b1c9ba7a3115"
-dependencies = [
- "crossbeam-utils",
-]
-
-[[package]]
-name = "crossbeam-skiplist"
-version = "0.1.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "df29de440c58ca2cc6e587ec3d22347551a32435fbde9d2bff64e78a9ffa151b"
-dependencies = [
- "crossbeam-epoch",
- "crossbeam-utils",
-]
-
 [[package]]
 name = "crossbeam-utils"
 version = "0.8.21"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d0a5c400df2834b80a4c3327b3aad3a4c4cd4de0629063962b03235697506a28"
 
-[[package]]
-name = "crypto-common"
-version = "0.1.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1bfb12502f3fc46cca1bb51ac28df9d618d813cdc3d2f25b9fe775a34af26bb3"
-dependencies = [
- "generic-array",
- "typenum",
-]
-
 [[package]]
 name = "d-engine"
-version = "0.1.3"
+version = "0.2.0"
 dependencies = [
- "arc-swap",
- "async-compression",
- "async-stream",
- "bincode",
- "bytes",
- "config",
- "crc32fast",
- "crossbeam",
- "crossbeam-skiplist",
- "dashmap",
- "flate2",
- "futures",
- "http-body",
- "http-body-util",
- "lru",
- "memmap2",
- "metrics",
- "nanoid",
- "parking_lot",
- "prost",
- "rand",
- "rcgen",
- "ring",
- "serde",
- "sha2",
- "tempfile",
- "thiserror",
- "tokio",
- "tokio-stream",
- "tokio-tar",
- "tokio-util",
- "tonic",
- "tonic-build",
- "tonic-health",
- "tracing",
- "vergen",
+ "d-engine-client",
 ]
 
 [[package]]
 name = "d-engine-bench"
-version = "0.1.4"
+version = "0.2.0"
 dependencies = [
  "atomic-shim",
  "bytes",
@@ -535,35 +322,42 @@ dependencies = [
 ]
 
 [[package]]
-name = "dashmap"
-version = "5.5.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "978747c1d849a7d2ee5e8adc0159961c48fb7e5db2f06af6723b80123bb53856"
+name = "d-engine-client"
+version = "0.2.0"
 dependencies = [
- "cfg-if",
- "hashbrown 0.14.5",
- "lock_api",
- "once_cell",
- "parking_lot_core",
+ "arc-swap",
+ "bytes",
+ "d-engine-proto",
+ "futures",
+ "rand",
+ "serde",
+ "tokio",
+ "tokio-stream",
+ "tonic",
+ "tonic-health",
+ "tracing",
 ]
 
 [[package]]
-name = "deranged"
-version = "0.5.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a41953f86f8a05768a6cda24def994fd2f424b04ec5c719cf89989779f199071"
+name = "d-engine-proto"
+version = "0.2.0"
 dependencies = [
- "powerfmt",
+ "bytes",
+ "prost",
+ "serde",
+ "tonic",
+ "tonic-build",
+ "tracing",
+ "vergen",
 ]
 
 [[package]]
-name = "digest"
-version = "0.10.7"
+name = "deranged"
+version = "0.5.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9ed9a281f7bc9b7576e61468ba615a66a5c8cfdff42420a70aa82701a3b1e292"
+checksum = "ececcb659e7ba858fb4f10388c250a7252eb0a27373f1a72b8748afdd248e587"
 dependencies = [
- "block-buffer",
- "crypto-common",
+ "powerfmt",
 ]
 
 [[package]]
@@ -594,18 +388,6 @@ version = "2.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "37909eebbb50d72f9059c3b6d82c0463f2ff062c9e95845c43a6c9c0355411be"
 
-[[package]]
-name = "filetime"
-version = "0.2.26"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bc0505cd1b6fa6580283f6bdf70a73fcf4aba1184038c90902b92b3dd0df63ed"
-dependencies = [
- "cfg-if",
- "libc",
- "libredox",
- "windows-sys 0.60.2",
-]
-
 [[package]]
 name = "find-msvc-tools"
 version = "0.1.4"
@@ -620,12 +402,11 @@ checksum = "1d674e81391d1e1ab681a28d99df07927c6d4aa5b027d7da16ba32d1d21ecd99"
 
 [[package]]
 name = "flate2"
-version = "1.1.4"
+version = "1.1.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dc5a4e564e38c699f2880d3fda590bedc2e69f3f84cd48b457bd892ce61d0aa9"
+checksum = "bfe33edd8e85a12a67454e37f8c75e730830d83e313556ab9ebf9ee7fbeb3bfb"
 dependencies = [
  "crc32fast",
- "libz-sys",
  "miniz_oxide",
 ]
 
@@ -635,12 +416,6 @@ version = "1.0.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3f9eec918d3f24069decb9af1554cad7c880e2da24a9afd88aca000531ab82c1"
 
-[[package]]
-name = "foldhash"
-version = "0.1.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d9c4f5dac5e15c24eb999c26181a6ca40b39fe946cbe4c263c7209467bc83af2"
-
 [[package]]
 name = "futures"
 version = "0.3.31"
@@ -730,16 +505,6 @@ dependencies = [
  "slab",
 ]
 
-[[package]]
-name = "generic-array"
-version = "0.14.8"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1dc8f7d2ded5f9209535e4b3fd4d39c002f30902ff5ce9f64e2c33d549576500"
-dependencies = [
- "typenum",
- "version_check",
-]
-
 [[package]]
 name = "getrandom"
 version = "0.2.16"
@@ -748,27 +513,21 @@ checksum = "335ff9f135e4384c8150d6f27c6daed433577f86b4750418338c01a1a2528592"
 dependencies = [
  "cfg-if",
  "libc",
- "wasi 0.11.1+wasi-snapshot-preview1",
+ "wasi",
 ]
 
 [[package]]
 name = "getrandom"
-version = "0.3.3"
+version = "0.3.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "26145e563e54f2cadc477553f1ec5ee650b00862f0a58bcd12cbdc5f0ea2d2f4"
+checksum = "899def5c37c4fd7b2664648c28120ecec138e4d395b459e5ca34f9cce2dd77fd"
 dependencies = [
  "cfg-if",
  "libc",
  "r-efi",
- "wasi 0.14.7+wasi-0.2.4",
+ "wasip2",
 ]
 
-[[package]]
-name = "gimli"
-version = "0.32.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e629b9b98ef3dd8afe6ca2bd0f89306cec16d43d907889945bc5d6687f2f13c7"
-
 [[package]]
 name = "h2"
 version = "0.4.12"
@@ -781,7 +540,7 @@ dependencies = [
  "futures-core",
  "futures-sink",
  "http",
- "indexmap 2.11.4",
+ "indexmap 2.12.0",
  "slab",
  "tokio",
  "tokio-util",
@@ -794,23 +553,6 @@ version = "0.12.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8a9ee70c43aaf417c914396645a0fa852624801b24ebb7ae78fe8272889ac888"
 
-[[package]]
-name = "hashbrown"
-version = "0.14.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e5274423e17b7c9fc20b6e7e208532f9b19825d82dfd615708b70edd83df41f1"
-
-[[package]]
-name = "hashbrown"
-version = "0.15.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9229cfe53dfd69f0609a49f65461bd93001ea1ef889cd5529dd176593f5338a1"
-dependencies = [
- "allocator-api2",
- "equivalent",
- "foldhash",
-]
-
 [[package]]
 name = "hashbrown"
 version = "0.16.0"
@@ -952,30 +694,19 @@ dependencies = [
 
 [[package]]
 name = "indexmap"
-version = "2.11.4"
+version = "2.12.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4b0f83760fb341a774ed326568e19f5a863af4a952def8c39f9ab92fd95b88e5"
+checksum = "6717a8d2a5a929a1a2eb43a12812498ed141a0bcfb7e8f7844fbdbe4303bba9f"
 dependencies = [
  "equivalent",
  "hashbrown 0.16.0",
 ]
 
-[[package]]
-name = "io-uring"
-version = "0.7.10"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "046fa2d4d00aea763528b4950358d0ead425372445dc8ff86312b3c69ff7727b"
-dependencies = [
- "bitflags 2.9.4",
- "cfg-if",
- "libc",
-]
-
 [[package]]
 name = "is_terminal_polyfill"
-version = "1.70.1"
+version = "1.70.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7943c866cc5cd64cbc25b2e01621d07fa8eb2a1a23160ee81ce38704e97b8ecf"
+checksum = "a6cb138bb79a146c1bd460005623e142ef0181e3d0219cb493e02f7d08a35695"
 
 [[package]]
 name = "itertools"
@@ -998,28 +729,6 @@ version = "0.2.177"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2874a2af47a2325c2001a6e6fad9b16a53b802102b528163885171cf92b15976"
 
-[[package]]
-name = "libredox"
-version = "0.1.10"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "416f7e718bdb06000964960ffa43b4335ad4012ae8b99060261aa4a8088d5ccb"
-dependencies = [
- "bitflags 2.9.4",
- "libc",
- "redox_syscall 0.5.18",
-]
-
-[[package]]
-name = "libz-sys"
-version = "1.1.22"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8b70e7a7df205e92a1a4cd9aaae7898dac0aa555503cc0a649494d0d60e7651d"
-dependencies = [
- "cc",
- "pkg-config",
- "vcpkg",
-]
-
 [[package]]
 name = "linux-raw-sys"
 version = "0.11.0"
@@ -1041,15 +750,6 @@ version = "0.4.28"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "34080505efa8e45a4b816c349525ebe327ceaa8559756f0356cba97ef3bf7432"
 
-[[package]]
-name = "lru"
-version = "0.15.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0281c2e25e62316a5c9d98f2d2e9e95a37841afdaf4383c177dbb5c1dfab0568"
-dependencies = [
- "hashbrown 0.15.5",
-]
-
 [[package]]
 name = "matchit"
 version = "0.7.3"
@@ -1062,25 +762,6 @@ version = "2.7.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f52b00d39961fc5b2736ea853c9cc86238e165017a493d1d5c8eac6bdc4cc273"
 
-[[package]]
-name = "memmap2"
-version = "0.9.8"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "843a98750cd611cc2965a8213b53b43e715f13c37a9e096c6408e69990961db7"
-dependencies = [
- "libc",
-]
-
-[[package]]
-name = "metrics"
-version = "0.24.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "25dea7ac8057892855ec285c440160265225438c3c45072613c25a4b26e98ef5"
-dependencies = [
- "ahash",
- "portable-atomic",
-]
-
 [[package]]
 name = "mime"
 version = "0.3.17"
@@ -1105,13 +786,13 @@ dependencies = [
 
 [[package]]
 name = "mio"
-version = "1.0.4"
+version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "78bed444cc8a2160f01cbcf811ef18cac863ad68ae8ca62092e8db51d51c761c"
+checksum = "69d83b0086dc8ecf3ce9ae2874b2d1290252e2a30720bea58a5c6639b0092873"
 dependencies = [
  "libc",
- "wasi 0.11.1+wasi-snapshot-preview1",
- "windows-sys 0.59.0",
+ "wasi",
+ "windows-sys 0.61.2",
 ]
 
 [[package]]
@@ -1120,15 +801,6 @@ version = "0.10.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1d87ecb2933e8aeadb3e3a02b828fed80a7528047e68b4f424523a0981a3a084"
 
-[[package]]
-name = "nanoid"
-version = "0.4.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3ffa00dec017b5b1a8b7cf5e2c008bfda1aa7e0697ac1508b491fdf2622fb4d8"
-dependencies = [
- "rand",
-]
-
 [[package]]
 name = "nom"
 version = "7.1.3"
@@ -1163,15 +835,6 @@ dependencies = [
  "libc",
 ]
 
-[[package]]
-name = "object"
-version = "0.37.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ff76201f031d8863c38aa7f905eca4f53abbfa15f609db4277d44cd8938f33fe"
-dependencies = [
- "memchr",
-]
-
 [[package]]
 name = "once_cell"
 version = "1.21.3"
@@ -1180,9 +843,9 @@ checksum = "42f5e15c9953c5e4ccceeb2e7382a716482c34515315f7b03532b8b4e8393d2d"
 
 [[package]]
 name = "once_cell_polyfill"
-version = "1.70.1"
+version = "1.70.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a4895175b425cb1f87721b59f0f286c2092bd4af812243672510e1ac53e2e0ad"
+checksum = "384b8ab6d37215f3c5301a95a4accb5d64aa607f1fcb26a11b5303878451b4fe"
 
 [[package]]
 name = "parking_lot"
@@ -1202,27 +865,11 @@ checksum = "2621685985a2ebf1c516881c026032ac7deafcda1a2c9b7850dc81e3dfcb64c1"
 dependencies = [
  "cfg-if",
  "libc",
- "redox_syscall 0.5.18",
+ "redox_syscall",
  "smallvec",
  "windows-link",
 ]
 
-[[package]]
-name = "pathdiff"
-version = "0.2.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "df94ce210e5bc13cb6651479fa48d14f601d9858cfe0467f43ae157023b938d3"
-
-[[package]]
-name = "pem"
-version = "3.0.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1d30c53c26bc5b31a98cd02d20f25a7c8567146caf63ed593a9d87b2775291be"
-dependencies = [
- "base64 0.22.1",
- "serde_core",
-]
-
 [[package]]
 name = "percent-encoding"
 version = "2.3.2"
@@ -1236,7 +883,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3672b37090dbd86368a4145bc067582552b29c27377cad4e0a306c97f9bd7772"
 dependencies = [
  "fixedbitset",
- "indexmap 2.11.4",
+ "indexmap 2.12.0",
 ]
 
 [[package]]
@@ -1271,18 +918,6 @@ version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8b870d8c151b6f2fb93e84a13146138f05d02ed11c7e7c54f8826aaaf7c9f184"
 
-[[package]]
-name = "pkg-config"
-version = "0.3.32"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7edddbd0b52d732b21ad9a5fab5c704c14cd949e5e9a1ec5929a24fded1b904c"
-
-[[package]]
-name = "portable-atomic"
-version = "1.11.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f84267b20a16ea918e43c6a88433c2d54fa145c92a811b5b047ccbe153674483"
-
 [[package]]
 name = "powerfmt"
 version = "0.2.0"
@@ -1310,9 +945,9 @@ dependencies = [
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.101"
+version = "1.0.103"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "89ae43fd86e4158d6db51ad8e2b80f313af9cc74f5c0e03ccb87de09998732de"
+checksum = "5ee95bc4ef87b8d5ba32e8b7714ccc834865276eab0aed5c9958d00ec45f49e8"
 dependencies = [
  "unicode-ident",
 ]
@@ -1414,42 +1049,20 @@ dependencies = [
  "getrandom 0.2.16",
 ]
 
-[[package]]
-name = "rcgen"
-version = "0.13.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "75e669e5202259b5314d1ea5397316ad400819437857b90861765f24c4cf80a2"
-dependencies = [
- "pem",
- "ring",
- "rustls-pki-types",
- "time",
- "yasna",
-]
-
-[[package]]
-name = "redox_syscall"
-version = "0.3.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "567664f262709473930a4bf9e51bf2ebf3348f2e748ccc50dea20646858f8f29"
-dependencies = [
- "bitflags 1.3.2",
-]
-
 [[package]]
 name = "redox_syscall"
 version = "0.5.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ed2bf2547551a7053d6fdfafda3f938979645c44812fbfcda098faae3f1a362d"
 dependencies = [
- "bitflags 2.9.4",
+ "bitflags",
 ]
 
 [[package]]
 name = "regex"
-version = "1.12.1"
+version = "1.12.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4a52d8d02cacdb176ef4678de6c052efb4b3da14b78e4db683a4252762be5433"
+checksum = "843bc0191f75f3e22651ae5f1e72939ab2f72a4bc30fa80a066bd66edefc24d4"
 dependencies = [
  "aho-corasick",
  "memchr",
@@ -1459,9 +1072,9 @@ dependencies = [
 
 [[package]]
 name = "regex-automata"
-version = "0.4.12"
+version = "0.4.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "722166aa0d7438abbaa4d5cc2c649dac844e8c56d82fb3d33e9c34b5cd268fc6"
+checksum = "5276caf25ac86c8d810222b3dbb938e512c55c6831a10f3e6ed1c93b84041f1c"
 dependencies = [
  "aho-corasick",
  "memchr",
@@ -1470,9 +1083,9 @@ dependencies = [
 
 [[package]]
 name = "regex-syntax"
-version = "0.8.7"
+version = "0.8.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c3160422bbd54dd5ecfdca71e5fd59b7b8fe2b1697ab2baf64f6d05dcc66d298"
+checksum = "7a2d987857b319362043e95f5353c0535c1f58eec5336fdfcf626430af7def58"
 
 [[package]]
 name = "ring"
@@ -1488,19 +1101,13 @@ dependencies = [
  "windows-sys 0.52.0",
 ]
 
-[[package]]
-name = "rustc-demangle"
-version = "0.1.26"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "56f7d92ca342cea22a06f2121d944b4fd82af56988c270852495420f961d4ace"
-
 [[package]]
 name = "rustix"
 version = "1.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cd15f8a2c5551a84d56efdc1cd049089e409ac19a3072d5037a17fd70719ff3e"
 dependencies = [
- "bitflags 2.9.4",
+ "bitflags",
  "errno",
  "libc",
  "linux-raw-sys",
@@ -1509,9 +1116,9 @@ dependencies = [
 
 [[package]]
 name = "rustls"
-version = "0.23.32"
+version = "0.23.34"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cd3c25631629d034ce7cd9940adc9d45762d46de2b0f57193c4443b92c6d4d40"
+checksum = "6a9586e9ee2b4f8fab52a0048ca7334d7024eef48e2cb9407e3497bb7cab7fa7"
 dependencies = [
  "log",
  "once_cell",
@@ -1533,18 +1140,18 @@ dependencies = [
 
 [[package]]
 name = "rustls-pki-types"
-version = "1.12.0"
+version = "1.13.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "229a4a4c221013e7e1f1a043678c5cc39fe5171437c88fb47151a21e6f5b5c79"
+checksum = "94182ad936a0c91c324cd46c6511b9510ed16af436d7b5bab34beab0afd55f7a"
 dependencies = [
  "zeroize",
 ]
 
 [[package]]
 name = "rustls-webpki"
-version = "0.103.7"
+version = "0.103.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e10b3f4191e8a80e6b43eebabfac91e5dcecebb27a71f04e820c47ec41d314bf"
+checksum = "2ffdfa2f5286e2247234e03f680868ac2815974dc39e00ea15adc445d0aafe52"
 dependencies = [
  "ring",
  "rustls-pki-types",
@@ -1593,26 +1200,6 @@ dependencies = [
  "syn",
 ]
 
-[[package]]
-name = "serde_spanned"
-version = "0.6.9"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bf41e0cfaf7226dca15e8197172c295a782857fcb97fad1808a166870dee75a3"
-dependencies = [
- "serde",
-]
-
-[[package]]
-name = "sha2"
-version = "0.10.9"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a7507d819769d01a365ab707794a4084392c824f54a7a6a7862f8c3d0892b283"
-dependencies = [
- "cfg-if",
- "cpufeatures",
- "digest",
-]
-
 [[package]]
 name = "shlex"
 version = "1.3.0"
@@ -1680,9 +1267,9 @@ checksum = "13c2bddecc57b384dee18652358fb23172facb8a2c51ccc10d74c157bdea3292"
 
 [[package]]
 name = "syn"
-version = "2.0.106"
+version = "2.0.108"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ede7c438028d4436d71104916910f5bb611972c5cfd7f89b8300a8186e6fada6"
+checksum = "da58917d35242480a05c2897064da0a80589a2a0476c9a3f2fdc83b53502e917"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -1702,7 +1289,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2d31c77bdf42a745371d260a26ca7163f1e0924b64afa0b688e61b5a9fa02f16"
 dependencies = [
  "fastrand",
- "getrandom 0.3.3",
+ "getrandom 0.3.4",
  "once_cell",
  "rustix",
  "windows-sys 0.61.2",
@@ -1763,29 +1350,26 @@ dependencies = [
 
 [[package]]
 name = "tokio"
-version = "1.47.1"
+version = "1.48.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "89e49afdadebb872d3145a5638b59eb0691ea23e46ca484037cfab3b76b95038"
+checksum = "ff360e02eab121e0bc37a2d3b4d4dc622e6eda3a8e5253d5435ecf5bd4c68408"
 dependencies = [
- "backtrace",
  "bytes",
- "io-uring",
  "libc",
  "mio",
  "parking_lot",
  "pin-project-lite",
  "signal-hook-registry",
- "slab",
  "socket2 0.6.1",
  "tokio-macros",
- "windows-sys 0.59.0",
+ "windows-sys 0.61.2",
 ]
 
 [[package]]
 name = "tokio-macros"
-version = "2.5.0"
+version = "2.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6e06d43f1345a3bcd39f6a56dbb7dcab2ba47e68e8ac134855e7e2bdbaf8cab8"
+checksum = "af407857209536a95c8e56f8231ef2c2e2aff839b22e07a1ffcbc617e9db9fa5"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -1813,21 +1397,6 @@ dependencies = [
  "tokio",
 ]
 
-[[package]]
-name = "tokio-tar"
-version = "0.3.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9d5714c010ca3e5c27114c1cdeb9d14641ace49874aa5626d7149e47aedace75"
-dependencies = [
- "filetime",
- "futures-core",
- "libc",
- "redox_syscall 0.3.5",
- "tokio",
- "tokio-stream",
- "xattr",
-]
-
 [[package]]
 name = "tokio-util"
 version = "0.7.16"
@@ -1841,47 +1410,6 @@ dependencies = [
  "tokio",
 ]
 
-[[package]]
-name = "toml"
-version = "0.8.23"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dc1beb996b9d83529a9e75c17a1686767d148d70663143c7854d8b4a09ced362"
-dependencies = [
- "serde",
- "serde_spanned",
- "toml_datetime",
- "toml_edit",
-]
-
-[[package]]
-name = "toml_datetime"
-version = "0.6.11"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "22cddaf88f4fbc13c51aebbf5f8eceb5c7c5a9da2ac40a13519eb5b0a0e8f11c"
-dependencies = [
- "serde",
-]
-
-[[package]]
-name = "toml_edit"
-version = "0.22.27"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "41fe8c660ae4257887cf66394862d21dbca4a6ddd26f04a3560410406a2f819a"
-dependencies = [
- "indexmap 2.11.4",
- "serde",
- "serde_spanned",
- "toml_datetime",
- "toml_write",
- "winnow",
-]
-
-[[package]]
-name = "toml_write"
-version = "0.1.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5d99f8c9a7727884afe522e9bd5edbfc91a3312b36a77b5fb8926e4c31a41801"
-
 [[package]]
 name = "tonic"
 version = "0.12.3"
@@ -2025,17 +1553,11 @@ version = "0.2.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e421abadd41a4225275504ea4d6566923418b7f05506fbc9c0fe86ba7396114b"
 
-[[package]]
-name = "typenum"
-version = "1.19.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "562d481066bde0658276a35467c4af00bdc6ee726305698a55b86e61d7ad82bb"
-
 [[package]]
 name = "unicode-ident"
-version = "1.0.19"
+version = "1.0.22"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f63a545481291138910575129486daeaf8ac54aee4387fe7906919f7830c7d9d"
+checksum = "9312f7c4f6ff9069b165498234ce8be658059c6728633667c526e27dc2cf1df5"
 
 [[package]]
 name = "untrusted"
@@ -2049,12 +1571,6 @@ version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "06abde3611657adf66d383f00b093d7faecc7fa57071cce2578660c9f1010821"
 
-[[package]]
-name = "vcpkg"
-version = "0.2.15"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "accd4ea62f7bb7a82fe23066fb0957d48ef677f6eeb8215f372f52e48bb32426"
-
 [[package]]
 name = "vergen"
 version = "8.3.2"
@@ -2067,12 +1583,6 @@ dependencies = [
  "time",
 ]
 
-[[package]]
-name = "version_check"
-version = "0.9.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0b928f33d975fc6ad9f86c8f283853ad26bdd5b10b7f1542aa2fa15e2289105a"
-
 [[package]]
 name = "want"
 version = "0.3.1"
@@ -2088,15 +1598,6 @@ version = "0.11.1+wasi-snapshot-preview1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ccf3ec651a847eb01de73ccad15eb7d99f80485de043efb2f370cd654f4ea44b"
 
-[[package]]
-name = "wasi"
-version = "0.14.7+wasi-0.2.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "883478de20367e224c0090af9cf5f9fa85bed63a95c1abf3afc5c083ebc06e8c"
-dependencies = [
- "wasip2",
-]
-
 [[package]]
 name = "wasip2"
 version = "1.0.1+wasi-0.2.4"
@@ -2121,15 +1622,6 @@ dependencies = [
  "windows-targets 0.52.6",
 ]
 
-[[package]]
-name = "windows-sys"
-version = "0.59.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1e38bc4d79ed67fd075bcc251a1c39b32a1776bbe92e5bef1f0bf1f8c531853b"
-dependencies = [
- "windows-targets 0.52.6",
-]
-
 [[package]]
 name = "windows-sys"
 version = "0.60.2"
@@ -2277,40 +1769,12 @@ version = "0.53.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d6bbff5f0aada427a1e5a6da5f1f98158182f26556f345ac9e04d36d0ebed650"
 
-[[package]]
-name = "winnow"
-version = "0.7.13"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "21a0236b59786fed61e2a80582dd500fe61f18b5dca67a4a067d0bc9039339cf"
-dependencies = [
- "memchr",
-]
-
 [[package]]
 name = "wit-bindgen"
 version = "0.46.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f17a85883d4e6d00e8a97c586de764dabcc06133f7f1d55dce5cdc070ad7fe59"
 
-[[package]]
-name = "xattr"
-version = "1.6.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "32e45ad4206f6d2479085147f02bc2ef834ac85886624a23575ae137c8aa8156"
-dependencies = [
- "libc",
- "rustix",
-]
-
-[[package]]
-name = "yasna"
-version = "0.5.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e17bb3549cc1321ae1296b9cdc2698e2b6cb1992adfa19a8c72e5b7a738f44cd"
-dependencies = [
- "time",
-]
-
 [[package]]
 name = "zerocopy"
 version = "0.8.27"
diff --git a/benches/d-engine-bench/Cargo.toml b/benches/d-engine-bench/Cargo.toml
index b547ff12..afddae6b 100644
--- a/benches/d-engine-bench/Cargo.toml
+++ b/benches/d-engine-bench/Cargo.toml
@@ -1,11 +1,11 @@
 [package]
 name = "d-engine-bench"
-version = "0.1.4"
-edition = "2021"
+version = "0.2.0"
+edition = "2024"
 
 [dependencies]
-d-engine = { path = "../../../d-engine" }
-# d-engine = { git = "https://github.com/deventlab/d-engine.git", branch = "feature/79-snapshot" }
+d-engine = { path = "../../d-engine", features = ["client"] }
+
 
 tokio = { version = "1.44", features = ["full"] }
 clap = { version = "4.5", features = ["derive"] }
diff --git a/benches/d-engine-bench/src/main.rs b/benches/d-engine-bench/src/main.rs
index b653c0f8..d413440f 100644
--- a/benches/d-engine-bench/src/main.rs
+++ b/benches/d-engine-bench/src/main.rs
@@ -1,18 +1,20 @@
-use std::sync::atomic::AtomicU64;
-use std::sync::atomic::Ordering;
 use std::sync::Arc;
 use std::sync::Mutex;
+use std::sync::atomic::AtomicU64;
+use std::sync::atomic::Ordering;
 use std::time::Duration;
 use std::time::Instant;
 
 use clap::Parser;
 use clap::Subcommand;
-use d_engine::proto::client::ReadConsistencyPolicy;
+use d_engine::Client;
+use d_engine::ClientApiError;
 use d_engine::ClientBuilder;
+use d_engine::protocol::ReadConsistencyPolicy;
 use hdrhistogram::Histogram;
-use rand::distributions::Alphanumeric;
 use rand::Rng;
 use rand::SeedableRng;
+use rand::distributions::Alphanumeric;
 use tokio::sync::Semaphore;
 
 #[derive(Parser, Debug, Clone)]
@@ -53,7 +55,7 @@ enum Commands {
 }
 
 struct ClientPool {
-    clients: Vec<Arc<d_engine::Client>>,
+    clients: Vec<Arc<Client>>,
     counter: AtomicU64,
 }
 
@@ -70,7 +72,7 @@ impl ClientPool {
     async fn new(
         endpoints: Vec<String>,
         pool_size: usize,
-    ) -> Result<Self, d_engine::ClientApiError> {
+    ) -> Result<Self, ClientApiError> {
         let mut clients = Vec::with_capacity(pool_size);
         for _ in 0..pool_size {
             let client = ClientBuilder::new(endpoints.clone())
@@ -87,7 +89,7 @@ impl ClientPool {
         })
     }
 
-    fn next(&self) -> Arc<d_engine::Client> {
+    fn next(&self) -> Arc<Client> {
         let idx = self.counter.fetch_add(1, Ordering::Relaxed);
         let len = self.clients.len() as u64;
         self.clients[(idx % len) as usize].clone()
@@ -281,10 +283,10 @@ mod tests {
     #[test]
     fn test_sequential_keys() {
         // Test the order keys from high to low
-        assert_eq!(generate_key(true, 6, 0), "999999");
-        assert_eq!(generate_key(true, 6, 1), "999998");
-        assert_eq!(generate_key(true, 3, 0), "999");
-        assert_eq!(generate_key(true, 3, 1), "998");
+        assert_eq!(generate_prefixed_key(true, 6, 0), "999999");
+        assert_eq!(generate_prefixed_key(true, 6, 1), "999998");
+        assert_eq!(generate_prefixed_key(true, 3, 0), "999");
+        assert_eq!(generate_prefixed_key(true, 3, 1), "998");
     }
 
     #[test]
@@ -298,17 +300,17 @@ mod tests {
     #[test]
     fn test_large_index() {
         // Test large index values ​​(will saturate to minimum value)
-        assert_eq!(generate_key(true, 3, 9999), "000"); // Saturate to minimum value
+        assert_eq!(generate_prefixed_key(true, 3, 9999), "000"); // Saturate to minimum value
     }
 
     #[test]
     fn test_random_keys() {
         // Test the determinism and randomness of the random key
-        let key1 = generate_key(false, 8, 42);
-        let key2 = generate_key(false, 8, 42);
+        let key1 = generate_prefixed_key(false, 8, 42);
+        let key2 = generate_prefixed_key(false, 8, 42);
         assert_eq!(key1, key2);
 
-        let key3 = generate_key(false, 8, 43);
+        let key3 = generate_prefixed_key(false, 8, 43);
         assert_ne!(key1, key3);
     }
 }
diff --git a/clippy.toml b/clippy.toml
new file mode 100644
index 00000000..cad9ec90
--- /dev/null
+++ b/clippy.toml
@@ -0,0 +1,200 @@
+# ============================================================================
+# Clippy Configuration for d-engine Workspace
+# ============================================================================
+# This file configures Clippy linting rules for the entire workspace.
+#
+# Documentation: https://rust-lang.github.io/rust-clippy/master/index.html
+# Configuration Reference: https://doc.rust-lang.org/clippy/configuration.html
+#
+# All workspace crates inherit these settings unless explicitly overridden
+# in crate-specific attributes (e.g., #[allow(clippy::foo)]).
+# ============================================================================
+
+# ============================================================================
+# Complexity and Performance Thresholds
+# ============================================================================
+
+# Maximum cognitive complexity threshold for functions
+# Default: 25
+# Functions exceeding this complexity will trigger cognitive_complexity warning
+cognitive-complexity-threshold = 30
+
+# Maximum number of function arguments before suggesting refactoring
+# Default: 7
+# Functions with more parameters than this will trigger too_many_arguments
+too-many-arguments-threshold = 8
+
+# Maximum number of lines in a function body
+# Default: 200
+# This helps identify functions that might be too large to understand easily
+too-many-lines-threshold = 250
+
+# Type complexity threshold
+# Default: 250
+# Complex generic types exceeding this threshold trigger type_complexity warning
+type-complexity-threshold = 300
+
+# ============================================================================
+# Code Style and Formatting Preferences
+# ============================================================================
+
+# Enforce explicit documentation on public API items
+# Set to true to require docs on all public items, modules, and functions
+# Default: false
+# For strict documentation standards, set to true
+missing-docs-in-crate-items = false
+
+# Enforce parentheses around complex expressions
+# Default: false
+# Set to true for more explicit parentheses
+enforce-iter-loop-reborrow = false
+
+
+# ============================================================================
+# Pattern-Specific Configuration
+# ============================================================================
+
+# Wildcard imports threshold
+# Default: None (allow all wildcard imports)
+# wildcard-imports-allowed-crates = ["log", "sqlx::prelude"]
+
+# Suppress warnings for specific lint patterns
+# This is useful for third-party code or when you know what you're doing
+# allowed-scripts = ["Latin"]
+
+# ============================================================================
+# Documentation and Comments
+# ============================================================================
+
+# Enforce documentation for public items in crates
+# Default: false
+# Set to true to require /// doc comments on public functions
+doc-valid-idents = [
+    # Standard Rust identifiers
+    "Raft",
+    "Tokio",
+    "RocksDB",
+    "TCP",
+    "UDP",
+    "HTTP",
+    "HTTPS",
+    "API",
+    "UUID",
+    "URL",
+    "UTF-8",
+    "CRC",
+    "SHA",
+    "LRU",
+    "LTO",
+    "LLVM",
+    "JIT",
+    "EOF",
+    "YAML",
+    "JSON",
+    "XML",
+    "ASCII",
+    "ANSI",
+    # Project-specific identifiers
+    "DEngine",
+    "d-engine",
+    "EventLab",
+    "Consensus",
+    "Replication",
+    "Quorum",
+    "Term",
+    "Index",
+]
+
+# Character name length thresholds
+single-char-binding-names-threshold = 4
+
+# ============================================================================
+# Safety and Correctness
+# ============================================================================
+
+# Restrict unsafe code to specific modules (optional)
+# When set, unsafe code outside specified modules triggers warnings
+# unsafe-derive-serialize = false
+
+# Check for potential panics
+# When true, warns about patterns that might panic
+# allow-panic = false
+
+# ============================================================================
+# Testing and Development
+# ============================================================================
+
+# Allow certain patterns in test code that would normally be warnings
+# Tests often use patterns that are acceptable in that context
+allow-unwrap-in-tests = true
+allow-expect-in-tests = true
+
+# ============================================================================
+# Import Organization
+# ============================================================================
+
+# Enforce wildcard imports are only from specific crates
+# Helps maintain clean imports
+# wildcard-imports-allowed-crates = []
+
+# ============================================================================
+# Lint Override Examples (Commented Out)
+# ============================================================================
+# The following are examples of how to suppress specific lints.
+# Uncomment if needed for your project.
+
+# # Suppress warnings for specific patterns:
+# # (In code, use #[allow(clippy::lint_name)])
+# # Example: #[allow(clippy::too_many_arguments)]
+
+# ============================================================================
+# Best Practices & Tips
+# ============================================================================
+#
+# 1. COGNITIVE COMPLEXITY (default: 25)
+#    - Functions with high cognitive complexity are harder to understand
+#    - Consider breaking them into smaller helper functions
+#    - Threshold of 30 allows for moderately complex functions
+#
+# 2. TOO MANY ARGUMENTS (default: 7)
+#    - Functions with many parameters are hard to call and maintain
+#    - Consider grouping related parameters into a struct
+#    - Threshold of 8 allows for functions with moderate parameter counts
+#
+# 3. TYPE COMPLEXITY (default: 250)
+#    - Complex generic types are hard to understand
+#    - Consider type aliases: type MyType = Vec<HashMap<String, Box<dyn Trait>>>;
+#
+# 4. DOCUMENTATION (default: off)
+#    - Set missing_docs_in_crate_items = true for well-documented public APIs
+#    - Use //! for module-level documentation
+#    - Use /// for item-level documentation
+#
+# 5. UNSAFE CODE
+#    - Always document why unsafe is necessary
+#    - Use #[allow(unsafe_code)] with comments explaining safety invariants
+#
+# 6. TESTING
+#    - allow_unwrap_in_tests = true is recommended for cleaner test code
+#    - Test code has different style requirements than production code
+#
+# ============================================================================
+# Common Clippy Lints to Be Aware Of
+# ============================================================================
+#
+# HIGH PRIORITY (usually should be fixed):
+#   - clippy::all: Enables all lint groups
+#   - clippy::correctness: Correctness issues that are bugs
+#   - clippy::perf: Performance anti-patterns
+#   - clippy::style: Code style issues
+#
+# MEDIUM PRIORITY (should usually be fixed):
+#   - clippy::pedantic: More aggressive lints, higher false positive rate
+#   - clippy::suspicious: Suspicious patterns that might be bugs
+#
+# LOW PRIORITY (contextual):
+#   - clippy::cargo: Build system specific lints
+#   - clippy::complexity: Unnecessarily complex code
+#   - clippy::nursery: Experimental lints not yet stable
+#
+# ============================================================================
diff --git a/config/base/raft.toml b/config/base/raft.toml
index c54e13db..809f4a67 100644
--- a/config/base/raft.toml
+++ b/config/base/raft.toml
@@ -52,7 +52,7 @@ sender_yield_every_n_chunks = 1
 receiver_yield_every_n_chunks = 1
 
 [raft.membership]
-cluster_healthcheck_probe_service_name = "raft.cluster.ClusterManagementService"
+cluster_healthcheck_probe_service_name = "d_engine.server.cluster.ClusterManagementService"
 
 [raft.auto_join]
 rpc_enable_compression = true
diff --git a/d-engine-client/Cargo.lock b/d-engine-client/Cargo.lock
new file mode 100644
index 00000000..cb5e7710
--- /dev/null
+++ b/d-engine-client/Cargo.lock
@@ -0,0 +1,1096 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "adler2"
+version = "2.0.1"
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+ "pin-project-lite",
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+checksum = "282be5f36a8ce781fad8c8ae18fa3f9beff57ec1b52cb3de0789201425d9a33d"
+dependencies = [
+ "windows-targets 0.52.6",
+]
+
+[[package]]
+name = "windows-sys"
+version = "0.60.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f2f500e4d28234f72040990ec9d39e3a6b950f9f22d3dba18416c35882612bcb"
+dependencies = [
+ "windows-targets 0.53.5",
+]
+
+[[package]]
+name = "windows-sys"
+version = "0.61.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ae137229bcbd6cdf0f7b80a31df61766145077ddf49416a728b02cb3921ff3fc"
+dependencies = [
+ "windows-link",
+]
+
+[[package]]
+name = "windows-targets"
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+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9b724f72796e036ab90c1021d4780d4d3d648aca59e491e6b98e725b84e99973"
+dependencies = [
+ "windows_aarch64_gnullvm 0.52.6",
+ "windows_aarch64_msvc 0.52.6",
+ "windows_i686_gnu 0.52.6",
+ "windows_i686_gnullvm 0.52.6",
+ "windows_i686_msvc 0.52.6",
+ "windows_x86_64_gnu 0.52.6",
+ "windows_x86_64_gnullvm 0.52.6",
+ "windows_x86_64_msvc 0.52.6",
+]
+
+[[package]]
+name = "windows-targets"
+version = "0.53.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
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+dependencies = [
+ "windows-link",
+ "windows_aarch64_gnullvm 0.53.1",
+ "windows_aarch64_msvc 0.53.1",
+ "windows_i686_gnu 0.53.1",
+ "windows_i686_gnullvm 0.53.1",
+ "windows_i686_msvc 0.53.1",
+ "windows_x86_64_gnu 0.53.1",
+ "windows_x86_64_gnullvm 0.53.1",
+ "windows_x86_64_msvc 0.53.1",
+]
+
+[[package]]
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+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "32a4622180e7a0ec044bb555404c800bc9fd9ec262ec147edd5989ccd0c02cd3"
+
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+checksum = "a9d8416fa8b42f5c947f8482c43e7d89e73a173cead56d044f6a56104a6d1b53"
+
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+
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+
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+
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+
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+
+[[package]]
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+
+[[package]]
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+checksum = "1e7ac75179f18232fe9c285163565a57ef8d3c89254a30685b57d83a38d326c2"
+
+[[package]]
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+
+[[package]]
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+source = "registry+https://github.com/rust-lang/crates.io-index"
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+
+[[package]]
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+checksum = "24d5b23dc417412679681396f2b49f3de8c1473deb516bd34410872eff51ed0d"
+
+[[package]]
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+
+[[package]]
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+
+[[package]]
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+checksum = "d6bbff5f0aada427a1e5a6da5f1f98158182f26556f345ac9e04d36d0ebed650"
+
+[[package]]
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+version = "0.8.27"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0894878a5fa3edfd6da3f88c4805f4c8558e2b996227a3d864f47fe11e38282c"
+dependencies = [
+ "zerocopy-derive",
+]
+
+[[package]]
+name = "zerocopy-derive"
+version = "0.8.27"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "88d2b8d9c68ad2b9e4340d7832716a4d21a22a1154777ad56ea55c51a9cf3831"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "zeroize"
+version = "1.8.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b97154e67e32c85465826e8bcc1c59429aaaf107c1e4a9e53c8d8ccd5eff88d0"
diff --git a/d-engine-client/Cargo.toml b/d-engine-client/Cargo.toml
new file mode 100644
index 00000000..e9000448
--- /dev/null
+++ b/d-engine-client/Cargo.toml
@@ -0,0 +1,34 @@
+[package]
+name = "d-engine-client"
+version = "0.2.0"
+edition = "2024"
+authors = ["Joshua Chi <joshokn@gmail.com>"]
+description = "Client library for connecting to d-engine Raft consensus servers"
+homepage = "https://github.com/deventlab/d-engine"
+repository = "https://github.com/deventlab/d-engine"
+license = "MIT OR Apache-2.0"
+keywords = ["raft", "consensus", "client", "async"]
+categories = ["asynchronous", "network-programming"]
+publish = false
+
+[package.metadata.docs.rs]
+all-features = true
+rustdoc-args = ["--cfg", "docsrs"]
+
+[dependencies]
+d-engine-proto = { workspace = true }
+
+tokio = { workspace = true }
+tonic = { workspace = true }
+tonic-health = { workspace = true }
+bytes =  { workspace = true }
+tracing = { workspace = true }
+serde = { workspace = true }
+rand = { workspace = true }
+arc-swap = "1.7.1"
+futures = { workspace = true }
+tokio-stream = "0.1.16"
+
+[dev-dependencies]
+mockall = "0.12.1"
+tracing-test = "0.2"
diff --git a/src/client/builder.rs b/d-engine-client/src/builder.rs
similarity index 97%
rename from src/client/builder.rs
rename to d-engine-client/src/builder.rs
index df8ed008..15d2b707 100644
--- a/src/client/builder.rs
+++ b/d-engine-client/src/builder.rs
@@ -80,7 +80,8 @@ impl ClientBuilder {
     ///
     /// # Example: Full Configuration
     /// ```no_run
-    /// use d_engine::client::{ClientBuilder, ClientConfig};
+    /// use d_engine_client::ClientBuilder;
+    /// use d_engine_client::ClientConfig;
     /// use std::time::Duration;
     ///
     /// let custom_config = ClientConfig {
diff --git a/src/client/cluster.rs b/d-engine-client/src/cluster.rs
similarity index 87%
rename from src/client/cluster.rs
rename to d-engine-client/src/cluster.rs
index 547ecdc9..21047533 100644
--- a/src/client/cluster.rs
+++ b/d-engine-client/src/cluster.rs
@@ -8,12 +8,11 @@ use tracing::error;
 use tracing::instrument;
 
 use super::ClientInner;
-use crate::proto::cluster::cluster_management_service_client::ClusterManagementServiceClient;
-use crate::proto::cluster::JoinRequest;
-use crate::proto::cluster::JoinResponse;
-use crate::proto::cluster::NodeMeta;
 use crate::ClientApiError;
-use crate::Result;
+use d_engine_proto::server::cluster::JoinRequest;
+use d_engine_proto::server::cluster::JoinResponse;
+use d_engine_proto::server::cluster::NodeMeta;
+use d_engine_proto::server::cluster::cluster_management_service_client::ClusterManagementServiceClient;
 
 /// Cluster administration interface
 ///
@@ -44,7 +43,7 @@ impl ClusterClient {
     /// - IP address
     /// - Port
     /// - Role (Leader/Follower)
-    pub async fn list_members(&self) -> Result<Vec<NodeMeta>> {
+    pub async fn list_members(&self) -> std::result::Result<Vec<NodeMeta>, ClientApiError> {
         let client_inner = self.client_inner.load();
 
         Ok(client_inner.pool.get_all_members())
diff --git a/src/client/cluster_test.rs b/d-engine-client/src/cluster_test.rs
similarity index 86%
rename from src/client/cluster_test.rs
rename to d-engine-client/src/cluster_test.rs
index 203cd9ea..b0b7a5af 100644
--- a/src/client/cluster_test.rs
+++ b/d-engine-client/src/cluster_test.rs
@@ -2,22 +2,21 @@ use std::sync::Arc;
 use std::vec;
 
 use arc_swap::ArcSwap;
+use d_engine_proto::common::NodeRole;
 use tokio::sync::oneshot;
 use tonic::Status;
 use tracing_test::traced_test;
 
-use crate::proto::cluster::ClusterMembership;
-use crate::proto::cluster::JoinResponse;
-use crate::proto::cluster::NodeMeta;
-use crate::proto::common::NodeStatus;
-use crate::proto::error::ErrorCode;
-use crate::test_utils::MockNode;
 use crate::ClientConfig;
 use crate::ClientInner;
 use crate::ClusterClient;
 use crate::ConnectionPool;
-use crate::FOLLOWER;
-use crate::LEADER;
+use crate::mock_rpc_service::MockNode;
+use d_engine_proto::common::NodeStatus;
+use d_engine_proto::error::ErrorCode;
+use d_engine_proto::server::cluster::ClusterMembership;
+use d_engine_proto::server::cluster::JoinResponse;
+use d_engine_proto::server::cluster::NodeMeta;
 
 #[tokio::test]
 #[traced_test]
@@ -48,7 +47,7 @@ async fn test_list_members_success() {
 
     let members = client.list_members().await.expect("Should get members");
     assert_eq!(members.len(), 1);
-    assert_eq!(members[0].role, LEADER);
+    assert_eq!(members[0].role, NodeRole::Leader.into());
 }
 
 #[tokio::test]
@@ -62,7 +61,7 @@ async fn test_join_cluster_success() {
                 version: 1,
                 nodes: vec![NodeMeta {
                     id: 1,
-                    role: LEADER,
+                    role: NodeRole::Leader.into(),
                     address: format!("127.0.0.1:{port}",),
                     status: NodeStatus::Active.into(),
                 }],
@@ -92,7 +91,7 @@ async fn test_join_cluster_success() {
 
     let request = NodeMeta {
         id: 2,
-        role: FOLLOWER,
+        role: NodeRole::Follower.into(),
         address: "127.0.0.1:50052".to_string(),
         status: NodeStatus::Active.into(),
     };
@@ -131,7 +130,7 @@ async fn test_join_cluster_failure() {
 
     let request = NodeMeta {
         id: 2,
-        role: LEADER,
+        role: NodeRole::Leader.into(),
         address: "127.0.0.1:50052".to_string(),
         status: NodeStatus::Active.into(),
     };
@@ -139,13 +138,13 @@ async fn test_join_cluster_failure() {
     // Simulate leader rejection
     let mut leader_node = NodeMeta {
         id: 1,
-        role: LEADER,
+        role: NodeRole::Leader.into(),
         address: "127.0.0.1:50051".to_string(),
         status: NodeStatus::Active.into(),
     };
-    leader_node.role = LEADER;
+    leader_node.role = NodeRole::Leader.into();
 
     let result = client.join_cluster(request).await;
     assert!(result.is_err());
-    assert_eq!(result.unwrap_err().code(), ErrorCode::StaleOperation as u32);
+    assert_eq!(result.unwrap_err().code(), ErrorCode::StaleOperation);
 }
diff --git a/src/client/config.rs b/d-engine-client/src/config.rs
similarity index 98%
rename from src/client/config.rs
rename to d-engine-client/src/config.rs
index 12d5f266..cd33f7bc 100644
--- a/src/client/config.rs
+++ b/d-engine-client/src/config.rs
@@ -1,6 +1,6 @@
 use std::time::Duration;
 
-use crate::time::get_now_as_u32;
+use crate::utils::get_now_as_u32;
 
 /// Client configuration parameters for network connection management
 ///
diff --git a/src/client/error.rs b/d-engine-client/src/error.rs
similarity index 65%
rename from src/client/error.rs
rename to d-engine-client/src/error.rs
index 2502ec28..3dec6e9a 100644
--- a/src/client/error.rs
+++ b/d-engine-client/src/error.rs
@@ -6,15 +6,14 @@ use tokio::task::JoinError;
 use tonic::Code;
 use tonic::Status;
 
-use crate::proto::error::ErrorCode;
+use d_engine_proto::error::ErrorCode;
 
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub enum ClientApiError {
     /// Network layer error (retryable)
     #[serde(rename = "network")]
     Network {
-        code: u32,
-        kind: NetworkErrorType,
+        code: ErrorCode,
         message: String,
         retry_after_ms: Option<u64>,
         #[serde(skip_serializing_if = "Option::is_none")]
@@ -24,8 +23,7 @@ pub enum ClientApiError {
     /// Protocol layer error (client needs to check protocol compatibility)
     #[serde(rename = "protocol")]
     Protocol {
-        code: u32,
-        kind: ProtocolErrorType,
+        code: ErrorCode,
         message: String,
         #[serde(skip_serializing_if = "Option::is_none")]
         supported_versions: Option<Vec<String>>,
@@ -33,17 +31,12 @@ pub enum ClientApiError {
 
     /// Storage layer error (internal problem on the server)
     #[serde(rename = "storage")]
-    Storage {
-        code: u32,
-        kind: StorageErrorType,
-        message: String,
-    },
+    Storage { code: ErrorCode, message: String },
 
     /// Business logic error (client needs to adjust behavior)
     #[serde(rename = "business")]
     Business {
-        code: u32,
-        kind: BusinessErrorType,
+        code: ErrorCode,
         message: String,
         #[serde(skip_serializing_if = "Option::is_none")]
         required_action: Option<String>,
@@ -52,57 +45,56 @@ pub enum ClientApiError {
     /// General Client API error
     #[serde(rename = "general")]
     General {
-        code: u32,
-        kind: GeneralErrorType,
+        code: ErrorCode,
         message: String,
         #[serde(skip_serializing_if = "Option::is_none")]
         required_action: Option<String>,
     },
 }
 
-#[derive(Debug, Clone, Serialize, Deserialize)]
-pub enum NetworkErrorType {
-    Timeout,
-    ConnectionLost,
-    InvalidAddress,
-    TlsFailure,
-    ProtocolViolation,
-    JoinError,
-}
-
-#[derive(Debug, Clone, Serialize, Deserialize)]
-pub enum ProtocolErrorType {
-    InvalidResponseFormat,
-    VersionMismatch,
-    ChecksumFailure,
-    SerializationError,
-}
-
-#[derive(Debug, Clone, Serialize, Deserialize)]
-pub enum StorageErrorType {
-    DiskFull,
-    CorruptionDetected,
-    IoFailure,
-    PermissionDenied,
-    KeyNotExist,
-}
-
-#[derive(Debug, Clone, Serialize, Deserialize)]
-pub enum BusinessErrorType {
-    NotLeader,
-    StaleRead,
-    InvalidRequest,
-    RateLimited,
-    ClusterUnavailable,
-    ProposeFailed,
-    RetryRequired,
-    StaleTerm,
-}
-
-#[derive(Debug, Clone, Serialize, Deserialize)]
-pub enum GeneralErrorType {
-    General,
-}
+// #[derive(Debug, Clone, Serialize, Deserialize)]
+// pub enum NetworkErrorType {
+//     Timeout,
+//     ConnectionLost,
+//     InvalidAddress,
+//     TlsFailure,
+//     ProtocolViolation,
+//     JoinError,
+// }
+
+// #[derive(Debug, Clone, Serialize, Deserialize)]
+// pub enum ProtocolErrorType {
+//     InvalidResponseFormat,
+//     VersionMismatch,
+//     ChecksumFailure,
+//     SerializationError,
+// }
+
+// #[derive(Debug, Clone, Serialize, Deserialize)]
+// pub enum StorageErrorType {
+//     DiskFull,
+//     CorruptionDetected,
+//     IoFailure,
+//     PermissionDenied,
+//     KeyNotExist,
+// }
+
+// #[derive(Debug, Clone, Serialize, Deserialize)]
+// pub enum BusinessErrorType {
+//     NotLeader,
+//     StaleRead,
+//     InvalidRequest,
+//     RateLimited,
+//     ClusterUnavailable,
+//     ProposeFailed,
+//     RetryRequired,
+//     StaleTerm,
+// }
+
+// #[derive(Debug, Clone, Serialize, Deserialize)]
+// pub enum GeneralErrorType {
+//     General,
+// }
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct LeaderInfo {
     pub id: String,
@@ -110,45 +102,46 @@ pub struct LeaderInfo {
     pub last_contact: u64, // Unix timestamp in ms
 }
 impl From<tonic::transport::Error> for ClientApiError {
+    /// Converts a tonic transport error into a ClientApiError
+    ///
+    /// This implementation handles different transport error scenarios:
+    /// - Connection timeouts
+    /// - Invalid URI/address formats
+    /// - Unexpected connection loss
+    ///
+    /// # Parameters
+    /// - `err`: The tonic transport error to convert
+    ///
+    /// # Returns
+    /// A ClientApiError with appropriate error code and retry information
     fn from(err: tonic::transport::Error) -> Self {
-        let (kind, message, retry) = match err {
-            e if e
-                .source()
-                .and_then(|e| e.downcast_ref::<std::io::Error>())
-                .map(|e| e.kind() == std::io::ErrorKind::TimedOut)
-                .unwrap_or(false) =>
-            {
-                (
-                    NetworkErrorType::Timeout,
-                    format!("Connection timeout: {e}"),
-                    Some(3000), // Retry after 3 seconds
-                )
+        // Determine the error details based on the underlying error
+        if let Some(io_err) = err.source().and_then(|e| e.downcast_ref::<std::io::Error>()) {
+            if io_err.kind() == std::io::ErrorKind::TimedOut {
+                return Self::Network {
+                    code: ErrorCode::ConnectionTimeout,
+                    message: format!("Connection timeout: {err}"),
+                    retry_after_ms: Some(3000), // Retry after 3 seconds
+                    leader_hint: None,
+                };
             }
-            e if e.to_string().contains("invalid uri") => (
-                NetworkErrorType::InvalidAddress,
-                format!("Invalid address: {e}"),
-                None,
-            ),
-            _ => (
-                NetworkErrorType::ConnectionLost,
-                "Connection unexpectedly closed".into(),
-                Some(5000),
-            ),
-        };
-
-        // Convert NetworkErrorType to an appropriate ErrorCode
-        let code = match kind {
-            NetworkErrorType::Timeout => ErrorCode::ConnectionTimeout,
-            NetworkErrorType::InvalidAddress => ErrorCode::InvalidAddress,
-            NetworkErrorType::ConnectionLost => ErrorCode::ConnectionTimeout,
-            _ => ErrorCode::Uncategorized,
-        };
-
-        ClientApiError::Network {
-            code: code as u32,
-            kind,
-            message,
-            retry_after_ms: retry,
+        }
+
+        // Check for invalid address errors
+        if err.to_string().contains("invalid uri") {
+            return Self::Network {
+                code: ErrorCode::InvalidAddress,
+                message: format!("Invalid address: {err}"),
+                retry_after_ms: None, // Not retryable - needs address correction
+                leader_hint: None,
+            };
+        }
+
+        // Default case: unexpected connection loss
+        Self::Network {
+            code: ErrorCode::ConnectionTimeout,
+            message: "Connection unexpectedly closed".into(),
+            retry_after_ms: Some(5000), // Retry after 5 seconds
             leader_hint: None,
         }
     }
@@ -161,15 +154,13 @@ impl From<Status> for ClientApiError {
 
         match code {
             Code::Unavailable => Self::Business {
-                code: ErrorCode::ClusterUnavailable as u32,
-                kind: BusinessErrorType::ClusterUnavailable,
+                code: ErrorCode::ClusterUnavailable,
                 message,
                 required_action: Some("Retry after cluster recovery".into()),
             },
 
             Code::Cancelled => Self::Network {
-                code: ErrorCode::ConnectionTimeout as u32,
-                kind: NetworkErrorType::Timeout,
+                code: ErrorCode::ConnectionTimeout,
                 message,
                 leader_hint: None,
                 retry_after_ms: Some(1000),
@@ -178,16 +169,14 @@ impl From<Status> for ClientApiError {
             Code::FailedPrecondition => {
                 if let Some(leader) = parse_leader_from_metadata(&status) {
                     Self::Network {
-                        code: ErrorCode::LeaderChanged as u32,
-                        kind: NetworkErrorType::ProtocolViolation,
+                        code: ErrorCode::LeaderChanged,
                         message: "Leadership changed".into(),
                         retry_after_ms: Some(1000),
                         leader_hint: Some(leader),
                     }
                 } else {
                     Self::Business {
-                        code: ErrorCode::StaleOperation as u32,
-                        kind: BusinessErrorType::StaleRead,
+                        code: ErrorCode::StaleOperation,
                         message,
                         required_action: Some("Refresh cluster state".into()),
                     }
@@ -195,22 +184,19 @@ impl From<Status> for ClientApiError {
             }
 
             Code::InvalidArgument => Self::Business {
-                code: ErrorCode::InvalidRequest as u32,
-                kind: BusinessErrorType::InvalidRequest,
+                code: ErrorCode::InvalidRequest,
                 message,
                 required_action: None,
             },
 
             Code::PermissionDenied => Self::Business {
-                code: ErrorCode::NotLeader as u32,
-                kind: BusinessErrorType::NotLeader,
+                code: ErrorCode::NotLeader,
                 message,
                 required_action: Some("Refresh cluster state".into()),
             },
 
             _ => Self::Business {
-                code: ErrorCode::Uncategorized as u32,
-                kind: BusinessErrorType::InvalidRequest,
+                code: ErrorCode::Uncategorized,
                 message: format!("Unhandled status code: {code:?}"),
                 required_action: None,
             },
@@ -218,6 +204,38 @@ impl From<Status> for ClientApiError {
     }
 }
 
+// impl ClientApiError {
+//     pub fn error_category(&self) -> ErrorCategory {
+//         match self.code() {
+//             ErrorCode::ConnectionTimeout
+//             | ErrorCode::InvalidAddress
+//             | ErrorCode::LeaderChanged
+//             | ErrorCode::JoinError => ErrorCategory::Network,
+
+//             ErrorCode::InvalidResponse | ErrorCode::VersionMismatch => ErrorCategory::Protocol,
+
+//             ErrorCode::DiskFull
+//             | ErrorCode::DataCorruption
+//             | ErrorCode::StorageIoError
+//             | ErrorCode::StoragePermissionDenied
+//             | ErrorCode::KeyNotExist => ErrorCategory::Storage,
+
+//             ErrorCode::NotLeader
+//             | ErrorCode::StaleOperation
+//             | ErrorCode::InvalidRequest
+//             | ErrorCode::RateLimited
+//             | ErrorCode::ClusterUnavailable
+//             | ErrorCode::ProposeFailed
+//             | ErrorCode::TermOutdated
+//             | ErrorCode::RetryRequired => ErrorCategory::Business,
+
+//             ErrorCode::General | ErrorCode::Uncategorized => ErrorCategory::General,
+
+//             _ => ErrorCategory::General,
+//         }
+//     }
+// }
+
 fn parse_leader_from_metadata(status: &Status) -> Option<LeaderInfo> {
     status
         .metadata()
@@ -261,29 +279,25 @@ impl From<ErrorCode> for ClientApiError {
         match code {
             // Network layer errors
             ErrorCode::ConnectionTimeout => ClientApiError::Network {
-                code: code as u32,
-                kind: NetworkErrorType::Timeout,
+                code,
                 message: "Connection timeout".to_string(),
                 retry_after_ms: None,
                 leader_hint: None,
             },
             ErrorCode::InvalidAddress => ClientApiError::Network {
-                code: code as u32,
-                kind: NetworkErrorType::InvalidAddress,
+                code,
                 message: "Invalid address".to_string(),
                 retry_after_ms: None,
                 leader_hint: None,
             },
             ErrorCode::LeaderChanged => ClientApiError::Network {
-                code: code as u32,
-                kind: NetworkErrorType::ConnectionLost,
+                code,
                 message: "Leader changed".to_string(),
                 retry_after_ms: Some(100), // suggest immediate retry
                 leader_hint: None,         // Note: This would ideally be populated from context
             },
             ErrorCode::JoinError => ClientApiError::Network {
-                code: code as u32,
-                kind: NetworkErrorType::JoinError,
+                code,
                 message: "Task Join Error".to_string(),
                 retry_after_ms: Some(100), // suggest immediate retry
                 leader_hint: None,         // Note: This would ideally be populated from context
@@ -291,105 +305,88 @@ impl From<ErrorCode> for ClientApiError {
 
             // Protocol layer errors
             ErrorCode::InvalidResponse => ClientApiError::Protocol {
-                code: code as u32,
-                kind: ProtocolErrorType::InvalidResponseFormat,
+                code,
                 message: "Invalid response format".to_string(),
                 supported_versions: None,
             },
             ErrorCode::VersionMismatch => ClientApiError::Protocol {
-                code: code as u32,
-                kind: ProtocolErrorType::VersionMismatch,
+                code,
                 message: "Version mismatch".to_string(),
                 supported_versions: None, // Note: This would ideally be populated from context
             },
 
             // Storage layer errors
             ErrorCode::DiskFull => ClientApiError::Storage {
-                code: code as u32,
-                kind: StorageErrorType::DiskFull,
+                code,
                 message: "Disk full".to_string(),
             },
             ErrorCode::DataCorruption => ClientApiError::Storage {
-                code: code as u32,
-                kind: StorageErrorType::CorruptionDetected,
+                code,
                 message: "Data corruption detected".to_string(),
             },
             ErrorCode::StorageIoError => ClientApiError::Storage {
-                code: code as u32,
-                kind: StorageErrorType::IoFailure,
+                code,
                 message: "Storage I/O error".to_string(),
             },
             ErrorCode::StoragePermissionDenied => ClientApiError::Storage {
-                code: code as u32,
-                kind: StorageErrorType::PermissionDenied,
+                code,
                 message: "Storage permission denied".to_string(),
             },
             ErrorCode::KeyNotExist => ClientApiError::Storage {
-                code: code as u32,
-                kind: StorageErrorType::KeyNotExist,
+                code,
                 message: "Key not exist in storage".to_string(),
             },
 
             // Business logic errors
             ErrorCode::NotLeader => ClientApiError::Business {
-                code: code as u32,
-                kind: BusinessErrorType::NotLeader,
+                code,
                 message: "Not leader".to_string(),
                 required_action: Some("redirect to leader".to_string()),
             },
             ErrorCode::StaleOperation => ClientApiError::Business {
-                code: code as u32,
-                kind: BusinessErrorType::StaleRead,
+                code,
                 message: "Stale operation".to_string(),
                 required_action: Some("refresh state and retry".to_string()),
             },
             ErrorCode::InvalidRequest => ClientApiError::Business {
-                code: code as u32,
-                kind: BusinessErrorType::InvalidRequest,
+                code,
                 message: "Invalid request".to_string(),
                 required_action: Some("check request parameters".to_string()),
             },
             ErrorCode::RateLimited => ClientApiError::Business {
-                code: code as u32,
-                kind: BusinessErrorType::RateLimited,
+                code,
                 message: "Rate limited".to_string(),
                 required_action: Some("wait and retry".to_string()),
             },
             ErrorCode::ClusterUnavailable => ClientApiError::Business {
-                code: code as u32,
-                kind: BusinessErrorType::ClusterUnavailable,
+                code,
                 message: "Cluster unavailable".to_string(),
                 required_action: Some("try again later".to_string()),
             },
             ErrorCode::ProposeFailed => ClientApiError::Business {
-                code: code as u32,
-                kind: BusinessErrorType::ProposeFailed,
+                code,
                 message: "Propose failed".to_string(),
                 required_action: Some("try again later".to_string()),
             },
             ErrorCode::Uncategorized => ClientApiError::Business {
-                code: code as u32,
-                kind: BusinessErrorType::InvalidRequest,
+                code,
                 message: "Uncategorized error".to_string(),
                 required_action: None,
             },
             ErrorCode::TermOutdated => ClientApiError::Business {
-                code: code as u32,
-                kind: BusinessErrorType::StaleTerm,
+                code,
                 message: "Stale term error".to_string(),
                 required_action: None,
             },
             ErrorCode::RetryRequired => ClientApiError::Business {
-                code: code as u32,
-                kind: BusinessErrorType::RetryRequired,
+                code,
                 message: "Retry required. Please try again.".to_string(),
                 required_action: None,
             },
 
             // Unclassified error
             ErrorCode::General => ClientApiError::General {
-                code: code as u32,
-                kind: GeneralErrorType::General,
+                code,
                 message: "General Client Api error".to_string(),
                 required_action: None,
             },
@@ -401,7 +398,7 @@ impl From<ErrorCode> for ClientApiError {
 
 impl ClientApiError {
     /// Returns the error code associated with this error
-    pub fn code(&self) -> u32 {
+    pub fn code(&self) -> ErrorCode {
         match self {
             ClientApiError::Network { code, .. } => *code,
             ClientApiError::Protocol { code, .. } => *code,
@@ -437,8 +434,7 @@ impl From<std::io::Error> for ClientApiError {
 impl ClientApiError {
     pub fn general_client_error(message: String) -> Self {
         ClientApiError::General {
-            code: ErrorCode::General as u32,
-            kind: GeneralErrorType::General,
+            code: ErrorCode::General,
             message,
             required_action: None,
         }
diff --git a/src/client/kv.rs b/d-engine-client/src/kv.rs
similarity index 92%
rename from src/client/kv.rs
rename to d-engine-client/src/kv.rs
index 02eb9976..26358112 100644
--- a/src/client/kv.rs
+++ b/d-engine-client/src/kv.rs
@@ -2,9 +2,9 @@ use std::sync::Arc;
 
 use arc_swap::ArcSwap;
 use bytes::Bytes;
-use rand::rngs::StdRng;
 use rand::Rng;
 use rand::SeedableRng;
+use rand::rngs::StdRng;
 use tonic::codec::CompressionEncoding;
 use tonic::transport::Channel;
 use tracing::debug;
@@ -12,15 +12,16 @@ use tracing::error;
 use tracing::warn;
 
 use super::ClientInner;
-use crate::proto::client::raft_client_service_client::RaftClientServiceClient;
-use crate::proto::client::ClientReadRequest;
-use crate::proto::client::ClientResult;
-use crate::proto::client::ClientWriteRequest;
-use crate::proto::client::ReadConsistencyPolicy;
-use crate::proto::client::WriteCommand;
-use crate::proto::error::ErrorCode;
-use crate::scoped_timer::ScopedTimer;
 use crate::ClientApiError;
+use crate::ClientResponseExt;
+use crate::scoped_timer::ScopedTimer;
+use d_engine_proto::client::ClientReadRequest;
+use d_engine_proto::client::ClientResult;
+use d_engine_proto::client::ClientWriteRequest;
+use d_engine_proto::client::ReadConsistencyPolicy;
+use d_engine_proto::client::WriteCommand;
+use d_engine_proto::client::raft_client_service_client::RaftClientServiceClient;
+use d_engine_proto::error::ErrorCode;
 
 /// Key-value store client interface
 ///
@@ -40,7 +41,8 @@ impl KvClient {
     ///
     /// # Errors
     /// - [`crate::ClientApiError::Network`] on network failures
-    /// - [`crate::ClientApiError::InvalidResponse`] for malformed server responses
+    /// - [`crate::ClientApiError::Protocol`] for protocol errors
+    /// - [`crate::ClientApiError::Storage`] for server-side storage errors
     pub async fn put(
         &self,
         key: impl AsRef<[u8]>,
@@ -87,8 +89,9 @@ impl KvClient {
     ///   (e.g. `String`, `&str`, `Vec<u8>`)
     ///
     /// # Errors
-    /// - [`Error::FailedToSendWriteRequestError`] if unable to reach the leader node
-    /// - [`Error::InvalidResponse`] for malformed server responses
+    /// - [`crate::ClientApiError::Network`] if unable to reach the leader node
+    /// - [`crate::ClientApiError::Protocol`] for protocol errors
+    /// - [`crate::ClientApiError::Storage`] for server-side storage errors
     pub async fn delete(
         &self,
         key: impl AsRef<[u8]>,
diff --git a/src/client/kv_test.rs b/d-engine-client/src/kv_test.rs
similarity index 96%
rename from src/client/kv_test.rs
rename to d-engine-client/src/kv_test.rs
index e0062951..645f6541 100644
--- a/src/client/kv_test.rs
+++ b/d-engine-client/src/kv_test.rs
@@ -1,26 +1,22 @@
-use std::sync::Arc;
-use std::vec;
-
 use arc_swap::ArcSwap;
 use bytes::Bytes;
+use std::sync::Arc;
+use std::vec;
 use tokio::sync::oneshot;
 use tracing_test::traced_test;
 
-use crate::proto::client::ClientResponse;
-use crate::proto::client::ClientResult;
-use crate::proto::client::ReadConsistencyPolicy;
-use crate::proto::cluster::ClusterMembership;
-use crate::proto::cluster::NodeMeta;
-use crate::proto::common::NodeStatus;
-use crate::proto::error::ErrorCode;
-use crate::test_utils::MockNode;
 use crate::Client;
 use crate::ClientConfig;
 use crate::ClientInner;
 use crate::ClusterClient;
 use crate::ConnectionPool;
 use crate::KvClient;
-use crate::LEADER;
+use crate::mock_rpc_service::MockNode;
+use d_engine_proto::client::ClientResponse;
+use d_engine_proto::client::ClientResult;
+use d_engine_proto::client::ReadConsistencyPolicy;
+use d_engine_proto::error::ErrorCode;
+use d_engine_proto::server::cluster::ClusterMembership;
 
 #[tokio::test]
 #[traced_test]
@@ -94,10 +90,7 @@ async fn test_put_failure() {
         )
         .await;
     assert!(result.is_err());
-    assert_eq!(
-        result.unwrap_err().code(),
-        ErrorCode::ConnectionTimeout as u32
-    );
+    assert_eq!(result.unwrap_err().code(), ErrorCode::ConnectionTimeout);
 }
 
 #[tokio::test]
@@ -134,13 +127,6 @@ async fn test_get_success() {
     })));
 
     // Set up mock response
-    let mut leader_node = NodeMeta {
-        id: 1,
-        role: LEADER,
-        address: "127.0.0.1:50051".to_string(),
-        status: NodeStatus::Active.into(),
-    };
-    leader_node.role = LEADER;
 
     let result = client.get_with_policy(key, Some(ReadConsistencyPolicy::LinearizableRead)).await;
     println!("{:?}", &result);
@@ -248,10 +234,7 @@ async fn test_delete_failure() {
 
     let result = client.delete(key).await;
     assert!(result.is_err());
-    assert_eq!(
-        result.unwrap_err().code(),
-        ErrorCode::ConnectionTimeout as u32
-    );
+    assert_eq!(result.unwrap_err().code(), ErrorCode::ConnectionTimeout);
 }
 #[tokio::test]
 #[traced_test]
@@ -431,10 +414,7 @@ async fn test_get_multi_failure() {
             .await;
 
         assert!(result.is_err());
-        assert_eq!(
-            result.unwrap_err().code(),
-            ErrorCode::ConnectionTimeout as u32
-        );
+        assert_eq!(result.unwrap_err().code(), ErrorCode::ConnectionTimeout);
     }
 }
 
@@ -471,7 +451,7 @@ async fn test_get_multi_empty_keys() {
     .await;
 
     assert!(result.is_err());
-    assert_eq!(result.unwrap_err().code(), ErrorCode::InvalidRequest as u32);
+    assert_eq!(result.unwrap_err().code(), ErrorCode::InvalidRequest);
 }
 
 #[tokio::test]
@@ -751,7 +731,7 @@ async fn test_get_consistency_methods_failure() {
         assert!(result.is_err(), "{method_name} should fail",);
         assert_eq!(
             result.unwrap_err().code(),
-            ErrorCode::ConnectionTimeout as u32,
+            ErrorCode::ConnectionTimeout,
             "{method_name} should return ConnectionTimeout",
         );
     }
@@ -1081,5 +1061,5 @@ async fn test_client_refresh_preserves_kv_and_cluster_clients() {
 
     let cluster_result = client.cluster().list_members().await;
     assert!(cluster_result.is_ok() || cluster_result.is_err()); // Either result is fine as long as
-                                                                // it doesn't panic
+    // it doesn't panic
 }
diff --git a/d-engine-client/src/lib.rs b/d-engine-client/src/lib.rs
new file mode 100644
index 00000000..fa9b87e9
--- /dev/null
+++ b/d-engine-client/src/lib.rs
@@ -0,0 +1,185 @@
+//! Client module for distributed consensus system
+//!
+//! Provides core components for interacting with the d_engine cluster:
+//! - [`Client`] - Main entry point with cluster access
+//! - [`ClientBuilder`] - Configurable client construction
+//! - [`KvClient`] - Key-value store operations
+//! - [`ClusterClient`] - Cluster management operations
+//! - [`ConnectionPool`] - Underlying connection management
+//!
+//! # Basic Usage
+//! ```no_run
+//! use d_engine_client::Client;
+//! use d_engine_client::ClientBuilder;
+//! use std::time::Duration;
+//! use core::error::Error;
+//!
+//! #[tokio::main(flavor = "current_thread")]
+//! async fn main(){
+//!     // Initialize client with automatic cluster discovery
+//!     let client = Client::builder(vec![
+//!         "http://node1:9081".into(),
+//!         "http://node2:9082".into()
+//!     ])
+//!     .connect_timeout(Duration::from_secs(3))
+//!     .request_timeout(Duration::from_secs(1))
+//!     .enable_compression(true)
+//!     .build()
+//!     .await
+//!     .unwrap();
+//!
+//!     // Execute key-value operations
+//!     client.kv().put("user:1001", "Alice").await.unwrap();
+//!
+//!     let value = client.kv().get("user:1001").await.unwrap();
+//!
+//!     println!("User data: {:?}", value);
+//!
+//!     // Perform cluster management
+//!     let members = client.cluster().list_members().await.unwrap();
+//!     println!("Cluster members: {:?}", members);
+//!
+//! }
+//! ```
+
+mod builder;
+mod cluster;
+mod config;
+mod error;
+mod kv;
+mod pool;
+mod proto;
+mod scoped_timer;
+mod utils;
+
+pub use builder::*;
+pub use cluster::*;
+pub use config::*;
+pub use error::*;
+pub use kv::*;
+pub use pool::*;
+pub use utils::*;
+
+// ==================== Protocol Types (Essential for Public API) ====================
+
+/// Protocol types needed for client operations
+///
+/// These types are used in the public API and must be imported for client usage:
+/// - `ClientResult`: Response type from read operations
+/// - `ReadConsistencyPolicy`: Consistency guarantees for reads
+/// - `WriteCommand`: Write operation specifications
+pub mod protocol {
+    pub use d_engine_proto::client::{ClientResult, ReadConsistencyPolicy, WriteCommand};
+}
+
+/// Cluster management protocol types
+///
+/// Types required for cluster administration operations:
+/// - `NodeMeta`: Cluster node metadata
+/// - `NodeStatus`: Node status enumeration
+pub mod cluster_types {
+    pub use d_engine_proto::common::NodeStatus;
+    pub use d_engine_proto::server::cluster::NodeMeta;
+}
+
+// ==================== Hide Implementation Details ====================
+pub(crate) use proto::*;
+
+#[cfg(test)]
+mod cluster_test;
+#[cfg(test)]
+mod kv_test;
+#[cfg(test)]
+mod mock_rpc;
+#[cfg(test)]
+mod mock_rpc_service;
+#[cfg(test)]
+mod pool_test;
+#[cfg(test)]
+mod utils_test;
+
+/// Main entry point for interacting with the d_engine cluster
+///
+/// Manages connections and provides access to specialized clients:
+/// - Use [`kv()`](Client::kv) for data operations
+/// - Use [`cluster()`](Client::cluster) for cluster administration
+///
+/// Created through the [`builder()`](Client::builder) method
+#[derive(Clone)]
+pub struct Client {
+    /// Key-value store client interface
+    kv: KvClient,
+
+    /// Cluster management client interface
+    cluster: ClusterClient,
+
+    inner: std::sync::Arc<arc_swap::ArcSwap<ClientInner>>,
+}
+
+#[derive(Clone)]
+pub struct ClientInner {
+    pool: ConnectionPool,
+    client_id: u32,
+    config: ClientConfig,
+    endpoints: Vec<String>,
+}
+
+impl Client {
+    /// Access the key-value operations client
+    ///
+    /// # Examples
+    /// ```rust,ignore
+    /// client.kv().put("key", "value").await?;
+    /// ```
+    pub fn kv(&self) -> &KvClient {
+        &self.kv
+    }
+
+    /// Access the cluster management client
+    ///
+    /// # Examples
+    /// ```rust,ignore
+    /// client.cluster().add_node("node3:9083").await?;
+    /// ```
+    pub fn cluster(&self) -> &ClusterClient {
+        &self.cluster
+    }
+
+    /// Create a configured client builder
+    ///
+    /// Starts client construction process with specified bootstrap endpoints.
+    /// Chain configuration methods before calling
+    /// [`build()`](ClientBuilder::build).
+    ///
+    /// # Arguments
+    /// * `endpoints` - Initial cluster nodes for discovery
+    ///
+    /// # Panics
+    /// Will panic if no valid endpoints provided
+    pub fn builder(endpoints: Vec<String>) -> ClientBuilder {
+        assert!(!endpoints.is_empty(), "At least one endpoint required");
+        ClientBuilder::new(endpoints)
+    }
+
+    pub async fn refresh(
+        &mut self,
+        new_endpoints: Option<Vec<String>>,
+    ) -> std::result::Result<(), ClientApiError> {
+        // Get a writable lock
+        let old_inner = self.inner.load();
+        let config = old_inner.config.clone();
+        let endpoints = new_endpoints.unwrap_or(old_inner.endpoints.clone());
+
+        let new_pool = ConnectionPool::create(endpoints.clone(), config.clone()).await?;
+
+        let new_inner = std::sync::Arc::new(ClientInner {
+            pool: new_pool,
+            client_id: old_inner.client_id,
+            config,
+            endpoints,
+        });
+
+        self.inner.store(new_inner);
+        Ok(())
+    }
+}
diff --git a/d-engine-client/src/mock_rpc.rs b/d-engine-client/src/mock_rpc.rs
new file mode 100644
index 00000000..001022d2
--- /dev/null
+++ b/d-engine-client/src/mock_rpc.rs
@@ -0,0 +1,127 @@
+use d_engine_proto::client::ClientReadRequest;
+use d_engine_proto::client::ClientResponse;
+use d_engine_proto::client::ClientWriteRequest;
+use d_engine_proto::client::raft_client_service_server::RaftClientService;
+use d_engine_proto::server::cluster::ClusterConfChangeRequest;
+use d_engine_proto::server::cluster::ClusterConfUpdateResponse;
+use d_engine_proto::server::cluster::ClusterMembership;
+use d_engine_proto::server::cluster::JoinRequest;
+use d_engine_proto::server::cluster::JoinResponse;
+use d_engine_proto::server::cluster::LeaderDiscoveryRequest;
+use d_engine_proto::server::cluster::LeaderDiscoveryResponse;
+use d_engine_proto::server::cluster::MetadataRequest;
+use d_engine_proto::server::cluster::cluster_management_service_server::ClusterManagementService;
+use std::sync::Arc;
+
+#[derive(Clone, Default)]
+pub struct MockRpcService {
+    pub server_port: Option<u16>,
+    // Expected responses for each method
+    pub expected_update_cluster_conf_response:
+        Option<Result<ClusterConfUpdateResponse, tonic::Status>>,
+    pub expected_client_propose_response: Option<Result<ClientResponse, tonic::Status>>,
+    pub expected_client_read_response: Option<Result<ClientResponse, tonic::Status>>,
+
+    #[allow(clippy::type_complexity)]
+    pub expected_metadata_response:
+        Option<Arc<dyn Fn(u16) -> Result<ClusterMembership, tonic::Status> + Send + Sync>>,
+
+    pub expected_join_cluster_response: Option<Result<JoinResponse, tonic::Status>>,
+    pub expected_discover_leader_response: Option<Result<LeaderDiscoveryResponse, tonic::Status>>,
+}
+impl MockRpcService {
+    pub fn with_metadata_response(
+        mut self,
+        f: impl Fn(u16) -> Result<ClusterMembership, tonic::Status> + Send + Sync + 'static,
+    ) -> Self {
+        self.expected_metadata_response = Some(Arc::new(f));
+        self
+    }
+
+    pub fn set_port(
+        &mut self,
+        port: u16,
+    ) {
+        self.server_port = Some(port);
+    }
+}
+
+#[tonic::async_trait]
+impl ClusterManagementService for MockRpcService {
+    async fn update_cluster_conf(
+        &self,
+        _request: tonic::Request<ClusterConfChangeRequest>,
+    ) -> std::result::Result<tonic::Response<ClusterConfUpdateResponse>, tonic::Status> {
+        match &self.expected_update_cluster_conf_response {
+            Some(Ok(response)) => Ok(tonic::Response::new(*response)),
+            Some(Err(status)) => Err(status.clone()),
+            None => Err(tonic::Status::unknown(
+                "No mock update_cluster_conf response set",
+            )),
+        }
+    }
+    async fn get_cluster_metadata(
+        &self,
+        _request: tonic::Request<MetadataRequest>,
+    ) -> std::result::Result<tonic::Response<ClusterMembership>, tonic::Status> {
+        match (&self.expected_metadata_response, self.server_port) {
+            (Some(f), Some(port)) => f(port).map(tonic::Response::new).map_err(|e| e.clone()),
+            _ => Err(tonic::Status::unimplemented(
+                "Metadata response not configured",
+            )),
+        }
+    }
+
+    async fn join_cluster(
+        &self,
+        _request: tonic::Request<JoinRequest>,
+    ) -> std::result::Result<tonic::Response<JoinResponse>, tonic::Status> {
+        match &self.expected_join_cluster_response {
+            Some(Ok(response)) => Ok(tonic::Response::new(response.clone())),
+            Some(Err(status)) => Err(status.clone()),
+            None => Err(tonic::Status::unknown("No mock join_cluster response set")),
+        }
+    }
+
+    async fn discover_leader(
+        &self,
+        _request: tonic::Request<LeaderDiscoveryRequest>,
+    ) -> std::result::Result<tonic::Response<LeaderDiscoveryResponse>, tonic::Status> {
+        match &self.expected_discover_leader_response {
+            Some(Ok(response)) => Ok(tonic::Response::new(response.clone())),
+            Some(Err(status)) => Err(status.clone()),
+            None => Err(tonic::Status::unknown(
+                "No mock discover_leader response set",
+            )),
+        }
+    }
+}
+
+#[tonic::async_trait]
+impl RaftClientService for MockRpcService {
+    async fn handle_client_write(
+        &self,
+        _request: tonic::Request<ClientWriteRequest>,
+    ) -> std::result::Result<tonic::Response<ClientResponse>, tonic::Status> {
+        match &self.expected_client_propose_response {
+            Some(Ok(response)) => Ok(tonic::Response::new(response.clone())),
+            Some(Err(status)) => Err(status.clone()),
+            None => Err(tonic::Status::unknown(
+                "No mock handle_client_write response set",
+            )),
+        }
+    }
+
+    async fn handle_client_read(
+        &self,
+        _request: tonic::Request<ClientReadRequest>,
+    ) -> std::result::Result<tonic::Response<ClientResponse>, tonic::Status> {
+        match &self.expected_client_read_response {
+            Some(Ok(response)) => Ok(tonic::Response::new(response.clone())),
+            Some(Err(status)) => Err(status.clone()),
+            None => Err(tonic::Status::unknown(
+                "No mock handle_client_read response set",
+            )),
+        }
+    }
+}
diff --git a/d-engine-client/src/mock_rpc_service.rs b/d-engine-client/src/mock_rpc_service.rs
new file mode 100644
index 00000000..edcc78fd
--- /dev/null
+++ b/d-engine-client/src/mock_rpc_service.rs
@@ -0,0 +1,212 @@
+use d_engine_proto::client::ClientResponse;
+use d_engine_proto::client::raft_client_service_server::RaftClientServiceServer;
+use d_engine_proto::common::NodeRole;
+use d_engine_proto::common::NodeStatus;
+use d_engine_proto::server::cluster::ClusterMembership;
+use d_engine_proto::server::cluster::JoinResponse;
+use d_engine_proto::server::cluster::NodeMeta;
+use d_engine_proto::server::cluster::cluster_management_service_server::ClusterManagementServiceServer;
+use std::net::SocketAddr;
+use std::sync::Arc;
+use tokio::net::TcpListener;
+use tokio::sync::oneshot;
+use tonic::Status;
+use tonic::codec::CompressionEncoding;
+use tonic::transport::Channel;
+use tonic_health::server::health_reporter;
+use tracing::debug;
+use tracing::info;
+
+use crate::mock_rpc::MockRpcService;
+
+pub struct MockNode;
+impl MockNode {
+    pub async fn mock_listener(
+        mut mock_service: MockRpcService,
+        rx: oneshot::Receiver<()>,
+        is_ready: bool,
+    ) -> std::result::Result<(u16, SocketAddr), tonic::Status> {
+        // Return port + address
+        let (mut health_reporter, health_service) = health_reporter();
+        if is_ready {
+            health_reporter.set_serving::<RaftClientServiceServer<MockNode>>().await;
+            health_reporter.set_serving::<ClusterManagementServiceServer<MockNode>>().await;
+            info!("set service is serving");
+        } else {
+            health_reporter.set_not_serving::<RaftClientServiceServer<MockNode>>().await;
+            health_reporter
+                .set_not_serving::<ClusterManagementServiceServer<MockNode>>()
+                .await;
+            info!("set service is not serving");
+        }
+
+        let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
+        let addr = listener
+            .local_addr()
+            .map_err(|e| tonic::Status::internal(format!("Failed to bind: {e}")))?;
+        let port = addr.port();
+        debug!("starting mock rpc service:port={port}",);
+
+        // Set the port in the service
+        mock_service.set_port(port);
+
+        let mock_service = Arc::new(mock_service);
+
+        let _r = tokio::spawn(async move {
+            tonic::transport::Server::builder()
+                .add_service(health_service)
+                .add_service(
+                    RaftClientServiceServer::from_arc(mock_service.clone())
+                        .accept_compressed(CompressionEncoding::Gzip)
+                        .send_compressed(CompressionEncoding::Gzip),
+                )
+                .add_service(
+                    ClusterManagementServiceServer::from_arc(mock_service.clone())
+                        .accept_compressed(CompressionEncoding::Gzip)
+                        .send_compressed(CompressionEncoding::Gzip),
+                )
+                // add as a dev-dependency the crate `tokio-stream` with feature `net` enabled
+                .serve_with_incoming_shutdown(
+                    tokio_stream::wrappers::TcpListenerStream::new(listener),
+                    async {
+                        rx.await.ok();
+                    },
+                )
+                // .serve_with_shutdown("127.0.0.1:50051".parse().unwrap(), )
+                .await
+                .unwrap();
+        });
+
+        Ok((port, addr)) // Return both port and address
+    }
+
+    // Update helper functions to handle dynamic ports
+    pub(crate) async fn mock_channel_with_port(port: u16) -> Channel {
+        Channel::from_shared(format!("http://127.0.0.1:{port}"))
+            .expect("valid address")
+            .connect()
+            .await
+            .expect("connection failed")
+    }
+
+    #[allow(clippy::type_complexity)]
+    pub(crate) async fn simulate_mock_service_with_cluster_conf_reps(
+        rx: oneshot::Receiver<()>,
+        response_builder: Option<
+            Box<dyn Fn(u16) -> std::result::Result<ClusterMembership, tonic::Status> + Send + Sync>,
+        >,
+    ) -> std::result::Result<(Channel, u16), tonic::Status> {
+        let builder = response_builder.unwrap_or_else(|| {
+            Box::new(|port: u16| {
+                Ok(ClusterMembership {
+                    version: 1,
+                    nodes: vec![NodeMeta {
+                        id: 1,
+                        role: NodeRole::Leader.into(),
+                        address: format!("127.0.0.1:{port}",),
+                        status: NodeStatus::Active.into(),
+                    }],
+                })
+            })
+        });
+
+        let mock_service = MockRpcService::default().with_metadata_response(builder);
+
+        let (port, _addr) = Self::mock_listener(mock_service, rx, true).await?;
+        let channel = Self::mock_channel_with_port(port).await;
+        Ok((channel, port))
+    }
+
+    #[allow(clippy::type_complexity)]
+    pub(crate) async fn simulate_client_read_mock_server(
+        rx: oneshot::Receiver<()>,
+        metadata_response_builder: Option<
+            Box<dyn Fn(u16) -> std::result::Result<ClusterMembership, tonic::Status> + Send + Sync>,
+        >,
+        response: ClientResponse,
+    ) -> std::result::Result<(Channel, u16), tonic::Status> {
+        let builder = metadata_response_builder.unwrap_or_else(|| {
+            Box::new(|port: u16| {
+                Ok(ClusterMembership {
+                    version: 1,
+                    nodes: vec![NodeMeta {
+                        id: 1,
+                        role: NodeRole::Leader.into(),
+                        address: format!("127.0.0.1:{port}",),
+                        status: NodeStatus::Active.into(),
+                    }],
+                })
+            })
+        });
+        let mock_service = MockRpcService {
+            expected_metadata_response: Some(Arc::new(builder)),
+            expected_client_read_response: Some(Ok(response)),
+            ..Default::default()
+        };
+        let (port, _addr) = Self::mock_listener(mock_service, rx, true).await?;
+        let channel = Self::mock_channel_with_port(port).await;
+        Ok((channel, port))
+    }
+
+    #[allow(clippy::type_complexity)]
+    pub(crate) async fn simulate_client_write_mock_server(
+        rx: oneshot::Receiver<()>,
+        metadata_response_builder: Option<
+            Box<dyn Fn(u16) -> std::result::Result<ClusterMembership, tonic::Status> + Send + Sync>,
+        >,
+        response: ClientResponse,
+    ) -> std::result::Result<(Channel, u16), tonic::Status> {
+        let builder = metadata_response_builder.unwrap_or_else(|| {
+            Box::new(|port: u16| {
+                Ok(ClusterMembership {
+                    version: 1,
+                    nodes: vec![NodeMeta {
+                        id: 1,
+                        role: NodeRole::Leader.into(),
+                        address: format!("127.0.0.1:{port}",),
+                        status: NodeStatus::Active.into(),
+                    }],
+                })
+            })
+        });
+        let mock_service = MockRpcService {
+            expected_metadata_response: Some(Arc::new(builder)),
+            expected_client_propose_response: Some(Ok(response)),
+            ..Default::default()
+        };
+        let (port, _addr) = Self::mock_listener(mock_service, rx, true).await?;
+        let channel = Self::mock_channel_with_port(port).await;
+        Ok((channel, port))
+    }
+
+    #[allow(clippy::type_complexity)]
+    pub async fn simulate_mock_service_with_join_cluster_reps(
+        rx: oneshot::Receiver<()>,
+        metadata_response_builder: Option<
+            Box<dyn Fn(u16) -> std::result::Result<ClusterMembership, tonic::Status> + Send + Sync>,
+        >,
+        join_response: std::result::Result<JoinResponse, Status>,
+    ) -> std::result::Result<(Channel, u16), tonic::Status> {
+        let builder = metadata_response_builder.unwrap_or_else(|| {
+            Box::new(|port: u16| {
+                Ok(ClusterMembership {
+                    version: 1,
+                    nodes: vec![NodeMeta {
+                        id: 1,
+                        role: NodeRole::Leader.into(),
+                        address: format!("127.0.0.1:{port}",),
+                        status: NodeStatus::Active.into(),
+                    }],
+                })
+            })
+        });
+        let mock_service = MockRpcService {
+            expected_metadata_response: Some(Arc::new(builder)),
+            expected_join_cluster_response: Some(join_response),
+            ..Default::default()
+        };
+        let (port, _addr) = Self::mock_listener(mock_service, rx, true).await?;
+        let channel = Self::mock_channel_with_port(port).await;
+        Ok((channel, port))
+    }
+}
diff --git a/src/client/pool.rs b/d-engine-client/src/pool.rs
similarity index 94%
rename from src/client/pool.rs
rename to d-engine-client/src/pool.rs
index daeb8e16..29c00a5e 100644
--- a/src/client/pool.rs
+++ b/d-engine-client/src/pool.rs
@@ -1,3 +1,4 @@
+use d_engine_proto::common::NodeRole;
 use tonic::codec::CompressionEncoding;
 use tonic::transport::Channel;
 use tonic::transport::Endpoint;
@@ -6,12 +7,12 @@ use tracing::error;
 use tracing::info;
 
 use super::ClientApiError;
-use crate::net::address_str;
-use crate::proto::cluster::cluster_management_service_client::ClusterManagementServiceClient;
-use crate::proto::cluster::MetadataRequest;
-use crate::proto::cluster::NodeMeta;
-use crate::proto::error::ErrorCode;
 use crate::ClientConfig;
+use crate::utils::address_str;
+use d_engine_proto::error::ErrorCode;
+use d_engine_proto::server::cluster::MetadataRequest;
+use d_engine_proto::server::cluster::NodeMeta;
+use d_engine_proto::server::cluster::cluster_management_service_client::ClusterManagementServiceClient;
 
 /// Manages connections to cluster nodes
 ///
@@ -181,7 +182,7 @@ impl ConnectionPool {
         for node in nodes {
             let addr = address_str(&node.address);
             debug!("parse_cluster_metadata, addr: {:?}", &addr);
-            if node.role == crate::LEADER {
+            if node.role == NodeRole::Leader.into() {
                 leader_addr = Some(addr);
             } else {
                 followers.push(addr);
diff --git a/src/client/pool_test.rs b/d-engine-client/src/pool_test.rs
similarity index 91%
rename from src/client/pool_test.rs
rename to d-engine-client/src/pool_test.rs
index 0d335318..5e8aafbd 100644
--- a/src/client/pool_test.rs
+++ b/d-engine-client/src/pool_test.rs
@@ -1,19 +1,18 @@
 use std::time::Duration;
 use std::vec;
 
+use d_engine_proto::common::NodeRole;
 use tokio::sync::oneshot;
 use tracing_test::traced_test;
 
-use crate::proto::cluster::ClusterMembership;
-use crate::proto::cluster::NodeMeta;
-use crate::proto::common::NodeStatus;
-use crate::proto::error::ErrorCode;
-use crate::test_utils::MockNode;
-use crate::time::get_now_as_u32;
 use crate::ClientConfig;
 use crate::ConnectionPool;
-use crate::FOLLOWER;
-use crate::LEADER;
+use crate::mock_rpc_service::MockNode;
+use crate::utils::get_now_as_u32;
+use d_engine_proto::common::NodeStatus;
+use d_engine_proto::error::ErrorCode;
+use d_engine_proto::server::cluster::ClusterMembership;
+use d_engine_proto::server::cluster::NodeMeta;
 
 #[tokio::test]
 #[traced_test]
@@ -21,13 +20,13 @@ async fn test_parse_cluster_metadata_success() {
     let nodes = vec![
         NodeMeta {
             id: 1,
-            role: LEADER,
+            role: NodeRole::Leader.into(),
             address: "127.0.0.1:50051".to_string(),
             status: NodeStatus::Active.into(),
         },
         NodeMeta {
             id: 2,
-            role: FOLLOWER,
+            role: NodeRole::Follower.into(),
             address: "127.0.0.1:50052".to_string(),
             status: NodeStatus::Active.into(),
         },
@@ -43,14 +42,14 @@ async fn test_parse_cluster_metadata_success() {
 async fn test_parse_cluster_metadata_no_leader() {
     let nodes = vec![NodeMeta {
         id: 1,
-        role: FOLLOWER,
+        role: NodeRole::Follower.into(),
         address: "127.0.0.1:50051".to_string(),
         status: NodeStatus::Active.into(),
     }];
 
     let result = ConnectionPool::parse_cluster_metadata(&nodes);
     let e = result.unwrap_err();
-    assert_eq!(e.code(), ErrorCode::NotLeader as u32);
+    assert_eq!(e.code(), ErrorCode::NotLeader);
 }
 
 #[tokio::test]
@@ -168,7 +167,7 @@ async fn test_refresh_successful_leader_change() {
                 version: 1,
                 nodes: vec![NodeMeta {
                     id: leader_id,
-                    role: LEADER,
+                    role: NodeRole::Leader.into(),
                     address: format!("127.0.0.1:{port}",),
                     status: NodeStatus::Active.into(),
                 }],
@@ -202,7 +201,7 @@ async fn test_refresh_successful_leader_change() {
                 version: 1,
                 nodes: vec![NodeMeta {
                     id: new_leader_id,
-                    role: LEADER,
+                    role: NodeRole::Leader.into(),
                     address: format!("127.0.0.1:{port}",),
                     status: NodeStatus::Active.into(),
                 }],
diff --git a/d-engine-client/src/proto/client_ext.rs b/d-engine-client/src/proto/client_ext.rs
new file mode 100644
index 00000000..0af1f2f1
--- /dev/null
+++ b/d-engine-client/src/proto/client_ext.rs
@@ -0,0 +1,178 @@
+use d_engine_proto::{
+    client::{ClientResponse, ClientResult, client_response::SuccessResult},
+    error::ErrorCode,
+};
+use tracing::error;
+
+use crate::ClientApiError;
+
+pub trait ClientResponseExt {
+    /// Convert response to boolean write result
+    ///
+    /// # Returns
+    /// - `Ok(true)` on successful write
+    /// - `Err` with converted error code on failure
+    #[allow(dead_code)]
+    fn into_write_result(self) -> std::result::Result<bool, ClientApiError>;
+
+    /// Convert response to read results
+    ///
+    /// # Returns
+    /// Vector of optional key-value pairs wrapped in Result
+    fn into_read_results(self) -> std::result::Result<Vec<Option<ClientResult>>, ClientApiError>;
+
+    /// Validate error code in response header
+    ///
+    /// # Internal Logic
+    /// Converts numeric error code to enum variant
+    fn validate_error(&self) -> std::result::Result<(), ClientApiError>;
+}
+
+impl ClientResponseExt for ClientResponse {
+    /// Convert response to boolean write result
+    ///
+    /// # Returns
+    /// - `Ok(true)` on successful write
+    /// - `Err` with converted error code on failure
+    fn into_write_result(self) -> std::result::Result<bool, ClientApiError> {
+        self.validate_error()?;
+        Ok(match self.success_result {
+            Some(SuccessResult::WriteAck(success)) => success,
+            _ => false,
+        })
+    }
+
+    /// Convert response to read results
+    ///
+    /// # Returns
+    /// Vector of optional key-value pairs wrapped in Result
+    fn into_read_results(self) -> std::result::Result<Vec<Option<ClientResult>>, ClientApiError> {
+        self.validate_error()?;
+        match &self.success_result {
+            Some(SuccessResult::ReadData(data)) => data
+                .results
+                .clone()
+                .into_iter()
+                .map(|item| {
+                    Ok(Some(ClientResult {
+                        key: item.key,
+                        value: item.value,
+                    }))
+                })
+                .collect(),
+            _ => {
+                let found = match &self.success_result {
+                    Some(SuccessResult::WriteAck(_)) => "WriteAck",
+                    None => "None",
+                    _ => "Unknown",
+                };
+                error!(
+                    "Unexpected response type for read operation: expected ReadData, found {}",
+                    found
+                );
+                Err(ClientApiError::Protocol {
+                    code: d_engine_proto::error::ErrorCode::InvalidResponse,
+                    message: format!("Unexpected response type: expected ReadData, found {found}",),
+                    supported_versions: None,
+                })
+            }
+        }
+    }
+
+    /// Validate error code in response header
+    ///
+    /// # Internal Logic
+    /// Converts numeric error code to enum variant
+    fn validate_error(&self) -> std::result::Result<(), ClientApiError> {
+        match ErrorCode::try_from(self.error).unwrap_or(ErrorCode::Uncategorized) {
+            ErrorCode::Success => Ok(()),
+            e => Err(e.into()),
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use bytes::Bytes;
+    use d_engine_proto::client::{ReadResults, client_response::SuccessResult};
+
+    #[test]
+    fn test_into_read_results_success() {
+        let response = ClientResponse {
+            error: ErrorCode::Success as i32,
+            metadata: None,
+            success_result: Some(SuccessResult::ReadData(ReadResults {
+                results: vec![ClientResult {
+                    key: Bytes::from(vec![1, 2, 3]),
+                    value: Bytes::from(vec![4, 5, 6]),
+                }],
+            })),
+        };
+
+        let result = response.into_read_results();
+        assert!(result.is_ok());
+        let data = result.unwrap();
+        assert_eq!(data.len(), 1);
+        assert!(data[0].is_some());
+    }
+
+    #[test]
+    fn test_into_read_results_wrong_variant_write_ack() {
+        let response = ClientResponse {
+            error: ErrorCode::Success as i32,
+            metadata: None,
+            success_result: Some(SuccessResult::WriteAck(true)),
+        };
+
+        let result = response.into_read_results();
+        assert!(result.is_err());
+
+        if let Err(ClientApiError::Protocol { code, message, .. }) = result {
+            assert_eq!(code, ErrorCode::InvalidResponse);
+            assert!(message.contains("expected ReadData"));
+            assert!(message.contains("found WriteAck"));
+        } else {
+            panic!("Expected Protocol error");
+        }
+    }
+
+    #[test]
+    fn test_into_read_results_none_variant() {
+        let response = ClientResponse {
+            error: ErrorCode::Success as i32,
+            metadata: None,
+            success_result: None,
+        };
+
+        let result = response.into_read_results();
+        assert!(result.is_err());
+
+        if let Err(ClientApiError::Protocol { code, message, .. }) = result {
+            assert_eq!(code, ErrorCode::InvalidResponse);
+            assert!(message.contains("expected ReadData"));
+            assert!(message.contains("found None"));
+        } else {
+            panic!("Expected Protocol error");
+        }
+    }
+
+    #[test]
+    fn test_into_read_results_with_error_code() {
+        let response = ClientResponse {
+            error: ErrorCode::NotLeader as i32,
+            metadata: None,
+            success_result: Some(SuccessResult::ReadData(ReadResults { results: vec![] })),
+        };
+
+        let result = response.into_read_results();
+        assert!(result.is_err());
+
+        // Should fail at validate_error() before checking success_result
+        if let Err(ClientApiError::Business { code, .. }) = result {
+            assert_eq!(code, ErrorCode::NotLeader);
+        } else {
+            panic!("Expected Business error with NotLeader code");
+        }
+    }
+}
diff --git a/d-engine-client/src/proto/mod.rs b/d-engine-client/src/proto/mod.rs
new file mode 100644
index 00000000..97e6d4b7
--- /dev/null
+++ b/d-engine-client/src/proto/mod.rs
@@ -0,0 +1,2 @@
+mod client_ext;
+pub use client_ext::*;
diff --git a/src/utils/scoped_timer.rs b/d-engine-client/src/scoped_timer.rs
similarity index 100%
rename from src/utils/scoped_timer.rs
rename to d-engine-client/src/scoped_timer.rs
diff --git a/d-engine-client/src/utils.rs b/d-engine-client/src/utils.rs
new file mode 100644
index 00000000..bf7ec87d
--- /dev/null
+++ b/d-engine-client/src/utils.rs
@@ -0,0 +1,40 @@
+use std::time::{Duration, SystemTime, UNIX_EPOCH};
+
+/// Returns seconds since epoch as u32
+/// # Warning
+/// This will overflow on 2038-01-19 (Year 2038 problem)
+#[inline]
+pub fn get_now_as_u32() -> u32 {
+    get_duration_since_epoch().as_secs() as u32
+}
+
+#[inline]
+pub fn get_duration_since_epoch() -> Duration {
+    SystemTime::now().duration_since(UNIX_EPOCH).expect("Time went backwards")
+}
+
+/// Normalizes an address string by ensuring it has a proper scheme prefix.
+///
+/// This function:
+/// - Detects and preserves existing "http://" or "https://" schemes
+/// - Defaults to "http://" when no scheme is present
+/// - Prevents scheme duplication
+///
+/// # Examples
+/// - "127.0.0.1:9000" -> "http://127.0.0.1:9000"
+/// - "http://127.0.0.1:9000" -> "http://127.0.0.1:9000"
+/// - "https://127.0.0.1:9000" -> "https://127.0.0.1:9000"
+/// - "node1:9000" -> "http://node1:9000"
+pub(crate) fn address_str(addr: &str) -> String {
+    // Detect if the address already has a scheme
+    if addr.starts_with("https://") {
+        // Preserve HTTPS scheme
+        addr.to_string()
+    } else if addr.starts_with("http://") {
+        // Preserve HTTP scheme
+        addr.to_string()
+    } else {
+        // No scheme present, default to HTTP
+        format!("http://{addr}",)
+    }
+}
diff --git a/d-engine-client/src/utils_test.rs b/d-engine-client/src/utils_test.rs
new file mode 100644
index 00000000..546fef07
--- /dev/null
+++ b/d-engine-client/src/utils_test.rs
@@ -0,0 +1,43 @@
+use super::*;
+
+#[test]
+fn test_address_str_no_scheme() {
+    assert_eq!(address_str("127.0.0.1:9000"), "http://127.0.0.1:9000");
+    assert_eq!(address_str("node1:9000"), "http://node1:9000");
+    assert_eq!(address_str("localhost:8080"), "http://localhost:8080");
+}
+
+#[test]
+fn test_address_str_preserves_http() {
+    assert_eq!(
+        address_str("http://127.0.0.1:9000"),
+        "http://127.0.0.1:9000"
+    );
+    assert_eq!(address_str("http://node1:9000"), "http://node1:9000");
+}
+
+#[test]
+fn test_address_str_preserves_https() {
+    assert_eq!(
+        address_str("https://127.0.0.1:9000"),
+        "https://127.0.0.1:9000"
+    );
+    assert_eq!(address_str("https://node1:9000"), "https://node1:9000");
+    assert_eq!(
+        address_str("https://secure.example.com:443"),
+        "https://secure.example.com:443"
+    );
+}
+
+#[test]
+fn test_address_str_no_duplication() {
+    // Ensure we don't accidentally create double schemes
+    assert_eq!(
+        address_str("http://127.0.0.1:9000"),
+        "http://127.0.0.1:9000"
+    );
+    assert_eq!(
+        address_str("https://127.0.0.1:9000"),
+        "https://127.0.0.1:9000"
+    );
+}
diff --git a/d-engine-core/Cargo.toml b/d-engine-core/Cargo.toml
new file mode 100644
index 00000000..53d5cb9e
--- /dev/null
+++ b/d-engine-core/Cargo.toml
@@ -0,0 +1,69 @@
+[package]
+name = "d-engine-core"
+version = "0.1.0"
+edition = "2024"
+authors = ["Joshua Chi <joshokn@gmail.com>"]
+description = "Core Raft consensus algorithm implementation and traits"
+homepage = "https://github.com/deventlab/d-engine"
+repository = "https://github.com/deventlab/d-engine"
+license = "MIT OR Apache-2.0"
+keywords = ["raft", "consensus", "algorithm"]
+categories = ["algorithms", "concurrency"]
+publish = false
+
+[package.metadata.docs.rs]
+all-features = true
+rustdoc-args = ["--cfg", "docsrs"]
+
+
+[features]
+test-utils = ["mockall","uuid", "tonic-health"]
+
+[dependencies]
+d-engine-proto = { workspace = true }
+
+tokio = { workspace = true }
+tonic = { workspace = true }
+bytes =  { workspace = true }
+tracing = { workspace = true }
+futures = { workspace = true }
+serde = { workspace = true }
+prost = { workspace = true }
+bincode = "1.3"
+thiserror = "1.0"
+nanoid = "0.4.0"
+sha2 = "0.10.9"
+# using Dashset
+dashmap = "5.5.3"
+tempfile = "3.19.1"
+metrics = { version = "0.24", features = [] }
+config = { version = "0.14.0", default-features = false, features = ["toml"] }
+tokio-stream = "0.1.16"
+# Packing/unpacking TAR archives
+tokio-tar = "0.3"
+rand = "0.8.5"
+lru = "0.15.0"
+memmap2 = "0.9.5"
+crc32fast = "1.4.2"
+# used in stream
+http-body = "1.0"
+http-body-util = "0.1.3"
+crossbeam-skiplist = "0.1"
+crossbeam = "0.8"
+mockall = { version = "0.12.1", optional = true }
+tonic-health = { version = "0.12.3", optional = true }
+# Compress/decompress data stream
+async-compression = { version = "0.4", features = ["tokio", "gzip"] }
+async-stream = "0.3.6"
+uuid = { version = "1", features = ["v4"], optional = true  }
+
+[dev-dependencies]
+tracing-test = "0.2"
+serial_test = "3.2.0"
+temp-env = "0.3.6"
+tokio = { version = "1", features = ["test-util", "process"] }
+parking_lot = "0.12.3"
+nix = { version = "0.30.1", features = ["fs"] }
+mockall = "0.12.1"
+tonic-health = "0.12.3"
+uuid = { version = "1", features = ["v4"] }
diff --git a/src/core/commit_handler/default_commit_handler.rs b/d-engine-core/src/commit_handler/default_commit_handler.rs
similarity index 98%
rename from src/core/commit_handler/default_commit_handler.rs
rename to d-engine-core/src/commit_handler/default_commit_handler.rs
index cf0a4628..b21d5927 100644
--- a/src/core/commit_handler/default_commit_handler.rs
+++ b/d-engine-core/src/commit_handler/default_commit_handler.rs
@@ -11,12 +11,6 @@ use tracing::trace;
 use tracing::warn;
 
 use super::CommitHandler;
-use crate::alias::MOF;
-use crate::alias::ROF;
-use crate::alias::SMHOF;
-use crate::proto::common::entry_payload::Payload;
-use crate::proto::common::Entry;
-use crate::scoped_timer::ScopedTimer;
 use crate::Membership;
 use crate::NewCommitData;
 use crate::RaftEvent;
@@ -25,6 +19,12 @@ use crate::RaftNodeConfig;
 use crate::Result;
 use crate::StateMachineHandler;
 use crate::TypeConfig;
+use crate::alias::MOF;
+use crate::alias::ROF;
+use crate::alias::SMHOF;
+use crate::scoped_timer::ScopedTimer;
+use d_engine_proto::common::Entry;
+use d_engine_proto::common::entry_payload::Payload;
 
 // Dependencies container
 pub struct CommitHandlerDependencies<T: TypeConfig> {
@@ -114,7 +114,7 @@ impl<T> DefaultCommitHandler<T>
 where
     T: TypeConfig,
 {
-    pub(crate) fn new(
+    pub fn new(
         my_id: u32,
         my_role: i32,
         my_current_term: u64,
@@ -277,8 +277,7 @@ where
             let entries = std::mem::take(batch);
             trace!(
                 "[Node-{}] Flushing command batch: {:?}",
-                self.my_id,
-                entries
+                self.my_id, entries
             );
             self.state_machine_handler.apply_chunk(entries).await?;
         }
diff --git a/src/core/commit_handler/default_commit_handler_test.rs b/d-engine-core/src/commit_handler/default_commit_handler_test.rs
similarity index 94%
rename from src/core/commit_handler/default_commit_handler_test.rs
rename to d-engine-core/src/commit_handler/default_commit_handler_test.rs
index d8e4a313..a0dbaf10 100644
--- a/src/core/commit_handler/default_commit_handler_test.rs
+++ b/d-engine-core/src/commit_handler/default_commit_handler_test.rs
@@ -12,24 +12,24 @@ use tokio::time::{self};
 use super::CommitHandler;
 use super::CommitHandlerDependencies;
 use super::DefaultCommitHandler;
-use crate::proto::common::membership_change::Change;
-use crate::proto::common::Entry;
-use crate::proto::common::EntryPayload;
-use crate::proto::common::LogId;
-use crate::proto::storage::SnapshotMetadata;
-use crate::test_utils::generate_insert_commands;
-use crate::test_utils::MockTypeConfig;
 use crate::CommitHandlerConfig;
 use crate::Error;
 use crate::MockMembership;
 use crate::MockRaftLog;
 use crate::MockStateMachineHandler;
+use crate::MockTypeConfig;
 use crate::NewCommitData;
 use crate::RaftConfig;
 use crate::RaftEvent;
 use crate::RaftNodeConfig;
 use crate::Result;
-use crate::LEADER;
+use crate::test_utils::generate_insert_commands;
+use d_engine_proto::common::Entry;
+use d_engine_proto::common::EntryPayload;
+use d_engine_proto::common::LogId;
+use d_engine_proto::common::NodeRole::Leader;
+use d_engine_proto::common::membership_change::Change;
+use d_engine_proto::server::storage::SnapshotMetadata;
 
 const TEST_TERM: u64 = 1;
 
@@ -313,7 +313,14 @@ fn setup(
         },
         ..Default::default()
     };
-    DefaultCommitHandler::<MockTypeConfig>::new(1, LEADER, 1, deps, Arc::new(config), new_commit_rx)
+    DefaultCommitHandler::<MockTypeConfig>::new(
+        1,
+        Leader.into(),
+        1,
+        deps,
+        Arc::new(config),
+        new_commit_rx,
+    )
 }
 
 /// # Case 1: interval_uses_correct_duration
@@ -403,11 +410,11 @@ mod run_test {
     use tokio::time;
 
     use super::*;
-    use crate::proto::common::membership_change::Change;
-    use crate::proto::common::AddNode;
-    use crate::proto::common::RemoveNode;
-    use crate::FOLLOWER;
-    use crate::LEADER;
+    use d_engine_proto::common::AddNode;
+    use d_engine_proto::common::NodeRole::Follower;
+    use d_engine_proto::common::NodeRole::Leader;
+    use d_engine_proto::common::RemoveNode;
+    use d_engine_proto::common::membership_change::Change;
 
     /// 1. Test happy path with all entry types
     #[tokio::test]
@@ -427,7 +434,7 @@ mod run_test {
 
         let last_applied = entries.len();
         let mut harness = setup_harness(
-            LEADER,
+            Leader.into(),
             1,
             entries,
             last_applied as u64,
@@ -441,7 +448,7 @@ mod run_test {
 
         // Send commits to trigger processing
         for i in 1..=4 {
-            harness.send_commit(i, LEADER).await;
+            harness.send_commit(i, Leader.into()).await;
         }
 
         // Verify snapshot triggered
@@ -464,7 +471,7 @@ mod run_test {
         );
         let last_applied = entries.len();
         let mut harness = setup_harness(
-            LEADER,
+            Leader.into(),
             1,
             entries,
             last_applied as u64,
@@ -476,8 +483,8 @@ mod run_test {
         );
 
         harness.run_handler().await;
-        harness.send_commit(1, LEADER).await;
-        harness.send_commit(2, FOLLOWER).await;
+        harness.send_commit(1, Leader.into()).await;
+        harness.send_commit(2, Follower.into()).await;
 
         // Should not process second command
         time::sleep(Duration::from_millis(50)).await;
@@ -497,7 +504,7 @@ mod run_test {
 
         let last_applied = entries.len();
         let mut harness = setup_harness(
-            LEADER,
+            Leader.into(),
             1,
             entries,
             last_applied as u64,
@@ -509,7 +516,7 @@ mod run_test {
         );
 
         harness.run_handler().await;
-        harness.send_commit(1, LEADER).await;
+        harness.send_commit(1, Leader.into()).await;
         time::sleep(Duration::from_millis(50)).await;
         harness.shutdown_tx.send(()).unwrap();
         harness.handle.unwrap().await.unwrap();
@@ -526,7 +533,7 @@ mod run_test {
 
         let last_applied = entries.len();
         let mut harness = setup_harness(
-            LEADER,
+            Leader.into(),
             1,
             entries,
             last_applied as u64,
@@ -540,7 +547,7 @@ mod run_test {
 
         // Send all commits at once
         for i in 1..=1000 {
-            harness.send_commit(i, LEADER).await;
+            harness.send_commit(i, Leader.into()).await;
         }
 
         println!("Sent all commits");
@@ -576,7 +583,7 @@ mod run_test {
 
         let last_applied = entries.len();
         let mut harness = setup_harness(
-            LEADER,
+            Leader.into(),
             1,
             entries,
             last_applied as u64,
@@ -590,7 +597,7 @@ mod run_test {
 
         // Send commits to trigger processing
         for i in 1..=2 {
-            harness.send_commit(i, LEADER).await;
+            harness.send_commit(i, Leader.into()).await;
         }
         tokio::time::advance(Duration::from_millis(3)).await;
         // Clean shutdown
@@ -629,7 +636,7 @@ mod run_test {
 
         let last_applied = entries.len();
         let mut harness = setup_harness(
-            LEADER,
+            Leader.into(),
             1,
             entries,
             last_applied as u64,
@@ -642,7 +649,7 @@ mod run_test {
         harness.run_handler().await;
 
         for i in 1..=batch_thresold {
-            harness.send_commit(i, LEADER).await;
+            harness.send_commit(i, Leader.into()).await;
         }
         tokio::time::advance(Duration::from_millis(2)).await;
         tokio::time::sleep(Duration::from_millis(2)).await;
@@ -682,7 +689,7 @@ mod run_test {
 
         let last_applied = entries.len();
         let mut harness = setup_harness(
-            LEADER,
+            Leader.into(),
             1,
             entries,
             last_applied as u64,
@@ -695,7 +702,7 @@ mod run_test {
         harness.run_handler().await;
 
         for i in 1..=(batch_thresold - 10) {
-            harness.send_commit(i, LEADER).await;
+            harness.send_commit(i, Leader.into()).await;
         }
         tokio::time::advance(Duration::from_millis(2)).await;
         tokio::time::sleep(Duration::from_millis(2)).await;
@@ -735,7 +742,7 @@ mod run_test {
 
         let last_applied = entries.len();
         let mut harness = setup_harness(
-            LEADER,
+            Leader.into(),
             1,
             entries,
             last_applied as u64,
@@ -748,7 +755,7 @@ mod run_test {
         harness.run_handler().await;
 
         for i in 1..=batch_thresold {
-            harness.send_commit(i, LEADER).await;
+            harness.send_commit(i, Leader.into()).await;
         }
         tokio::time::advance(Duration::from_millis(2)).await;
         tokio::time::sleep(Duration::from_millis(2)).await;
@@ -764,10 +771,10 @@ mod process_batch_test {
     use parking_lot::Mutex;
 
     use super::*;
-    use crate::proto::common::membership_change::Change;
-    use crate::proto::common::AddNode;
-    use crate::proto::common::RemoveNode;
     use crate::test_utils::*;
+    use d_engine_proto::common::AddNode;
+    use d_engine_proto::common::RemoveNode;
+    use d_engine_proto::common::membership_change::Change;
 
     // Test helper setup with configurable mocks
     // fn setup_test_handler<F, G>(
@@ -841,7 +848,7 @@ mod process_batch_test {
     async fn processes_empty_batch_successfully() {
         let last_applied = 0;
         let mut harness = setup_harness(
-            LEADER,
+            Leader.into(),
             1,
             vec![],
             last_applied as u64,
@@ -868,7 +875,7 @@ mod process_batch_test {
 
         let last_applied = entries.len();
         let mut harness = setup_harness(
-            LEADER,
+            Leader.into(),
             1,
             entries,
             last_applied as u64,
@@ -900,7 +907,7 @@ mod process_batch_test {
 
         let last_applied = entries.len();
         let mut harness = setup_harness(
-            LEADER,
+            Leader.into(),
             1,
             entries,
             last_applied as u64,
@@ -940,7 +947,7 @@ mod process_batch_test {
 
         let last_applied = entries.len();
         let mut harness = setup_harness(
-            LEADER,
+            Leader.into(),
             1,
             entries,
             last_applied as u64,
@@ -971,7 +978,7 @@ mod process_batch_test {
 
         let last_applied = entries.len();
         let mut harness = setup_harness(
-            LEADER,
+            Leader.into(),
             1,
             entries,
             last_applied as u64,
@@ -999,7 +1006,7 @@ mod process_batch_test {
 
         let last_applied = entries.len();
         let mut harness = setup_harness(
-            LEADER,
+            Leader.into(),
             1,
             entries,
             last_applied as u64,
@@ -1025,7 +1032,7 @@ mod process_batch_test {
 
         let last_applied = entries.len();
         let mut harness = setup_harness(
-            LEADER,
+            Leader.into(),
             1,
             entries,
             last_applied as u64,
@@ -1047,7 +1054,7 @@ mod process_batch_test {
 
         let last_applied = entries.len();
         let mut harness = setup_harness(
-            LEADER,
+            Leader.into(),
             1,
             entries,
             last_applied as u64,
@@ -1082,7 +1089,7 @@ mod process_batch_test {
 
         let last_applied = entries.len();
         let mut harness = setup_harness(
-            LEADER,
+            Leader.into(),
             1,
             entries,
             last_applied as u64,
@@ -1108,7 +1115,7 @@ mod process_batch_test {
         let entries = build_entries(r, 1);
         let last_applied = entries.len();
         let mut harness = setup_harness(
-            LEADER,
+            Leader.into(),
             1,
             entries,
             last_applied as u64,
@@ -1142,7 +1149,7 @@ mod process_batch_test {
         let order_capture = process_order.clone();
         let last_applied = entries.len();
         let mut harness = setup_harness(
-            LEADER,
+            Leader.into(),
             1,
             entries,
             last_applied as u64,
@@ -1191,7 +1198,7 @@ mod process_batch_test {
 
         let last_applied = entries.len();
         let mut harness = setup_harness(
-            LEADER,
+            Leader.into(),
             1,
             entries,
             last_applied as u64,
diff --git a/src/core/commit_handler/mod.rs b/d-engine-core/src/commit_handler/mod.rs
similarity index 96%
rename from src/core/commit_handler/mod.rs
rename to d-engine-core/src/commit_handler/mod.rs
index d2a91098..b0b9b677 100644
--- a/src/core/commit_handler/mod.rs
+++ b/d-engine-core/src/commit_handler/mod.rs
@@ -55,15 +55,13 @@ pub use default_commit_handler::*;
 #[cfg(test)]
 mod default_commit_handler_test;
 
-//--------------------------------
-// CommitHandler trait definition
-#[cfg(test)]
+#[cfg(any(test, feature = "test-utils"))]
 use mockall::automock;
 use tonic::async_trait;
 
 use crate::Result;
 
-#[cfg_attr(test, automock)]
+#[cfg_attr(any(test, feature = "test-utils"), automock)]
 #[async_trait]
 pub trait CommitHandler: Send + Sync + 'static {
     async fn run(&mut self) -> Result<()>;
diff --git a/src/config/cluster.rs b/d-engine-core/src/config/cluster.rs
similarity index 96%
rename from src/config/cluster.rs
rename to d-engine-core/src/config/cluster.rs
index 50a9de21..093b70eb 100644
--- a/src/config/cluster.rs
+++ b/d-engine-core/src/config/cluster.rs
@@ -6,11 +6,11 @@ use serde::Deserialize;
 use serde::Serialize;
 
 use super::validate_directory;
-use crate::proto::cluster::NodeMeta;
-use crate::proto::common::NodeStatus;
 use crate::Error;
 use crate::Result;
-use crate::FOLLOWER;
+use d_engine_proto::common::NodeRole::Follower;
+use d_engine_proto::common::NodeStatus;
+use d_engine_proto::server::cluster::NodeMeta;
 
 /// Cluster node configuration parameters
 ///
@@ -129,7 +129,7 @@ fn default_initial_cluster() -> Vec<NodeMeta> {
     vec![NodeMeta {
         id: 1,
         address: "127.0.0.1:8080".to_string(),
-        role: FOLLOWER,
+        role: Follower.into(),
         status: NodeStatus::Active.into(),
     }]
 }
diff --git a/src/config/config_test.rs b/d-engine-core/src/config/config_test.rs
similarity index 98%
rename from src/config/config_test.rs
rename to d-engine-core/src/config/config_test.rs
index e110af9e..fd325fc1 100644
--- a/src/config/config_test.rs
+++ b/d-engine-core/src/config/config_test.rs
@@ -6,7 +6,9 @@ use super::*;
 fn cleanup_all_raft_env_vars() {
     for (key, _) in std::env::vars() {
         if key.starts_with("RAFT__") || key == "CONFIG_PATH" {
-            std::env::remove_var(&key);
+            unsafe {
+                std::env::remove_var(&key);
+            }
         }
     }
 }
@@ -212,8 +214,8 @@ fn type_mismatch_in_config_should_fail_gracefully() {
 /// Tests for node join status detection
 mod join_status_tests {
     use super::*;
-    use crate::proto::cluster::NodeMeta;
-    use crate::proto::common::NodeStatus;
+    use d_engine_proto::common::NodeStatus;
+    use d_engine_proto::server::cluster::NodeMeta;
 
     /// # Case 1: Node is in joining status
     #[test]
diff --git a/src/config/mod.rs b/d-engine-core/src/config/mod.rs
similarity index 99%
rename from src/config/mod.rs
rename to d-engine-core/src/config/mod.rs
index b9a7108a..28a6e0f0 100644
--- a/src/config/mod.rs
+++ b/d-engine-core/src/config/mod.rs
@@ -34,9 +34,9 @@ use config::File;
 use serde::Deserialize;
 use serde::Serialize;
 
-use crate::proto::common::NodeStatus;
 use crate::Error;
 use crate::Result;
+use d_engine_proto::common::NodeStatus;
 
 /// Main configuration container for Raft consensus engine components
 ///
diff --git a/src/config/monitoring.rs b/d-engine-core/src/config/monitoring.rs
similarity index 100%
rename from src/config/monitoring.rs
rename to d-engine-core/src/config/monitoring.rs
diff --git a/src/config/network.rs b/d-engine-core/src/config/network.rs
similarity index 100%
rename from src/config/network.rs
rename to d-engine-core/src/config/network.rs
diff --git a/src/config/network_test.rs b/d-engine-core/src/config/network_test.rs
similarity index 100%
rename from src/config/network_test.rs
rename to d-engine-core/src/config/network_test.rs
index c6aebffc..86cb4dd6 100644
--- a/src/config/network_test.rs
+++ b/d-engine-core/src/config/network_test.rs
@@ -1,6 +1,6 @@
+use crate::Error;
 use crate::config::network::ConnectionParams;
 use crate::config::network::NetworkConfig;
-use crate::Error;
 
 // Helper function to create a valid base ConnectionParams for tests
 fn valid_base_params() -> ConnectionParams {
diff --git a/src/config/raft.rs b/d-engine-core/src/config/raft.rs
similarity index 95%
rename from src/config/raft.rs
rename to d-engine-core/src/config/raft.rs
index 4996ff5d..17c6d988 100644
--- a/src/config/raft.rs
+++ b/d-engine-core/src/config/raft.rs
@@ -128,11 +128,11 @@ impl RaftConfig {
         // Warn if lease duration is too long compared to election timeout
         if self.read_consistency.lease_duration_ms > self.election.election_timeout_min / 2 {
             warn!(
-                    "read_consistency.lease_duration_ms ({}) is greater than half of election_timeout_min ({}ms). \
+                "read_consistency.lease_duration_ms ({}) is greater than half of election_timeout_min ({}ms). \
                      This may cause lease expiration during normal operation.",
-                    self.read_consistency.lease_duration_ms,
-                    self.election.election_timeout_min / 2
-                );
+                self.read_consistency.lease_duration_ms,
+                self.election.election_timeout_min / 2
+            );
         }
 
         Ok(())
@@ -305,7 +305,7 @@ impl Default for MembershipConfig {
     }
 }
 fn default_probe_service() -> String {
-    "raft.cluster.ClusterManagementService".to_string()
+    "d_engine.server.cluster.ClusterManagementService".to_string()
 }
 
 // 30 seconds
@@ -416,6 +416,9 @@ pub struct SnapshotConfig {
     #[serde(default = "default_snapshots_dir")]
     pub snapshots_dir: PathBuf,
 
+    #[serde(default = "default_snapshots_dir_prefix")]
+    pub snapshots_dir_prefix: String,
+
     /// Size (in bytes) of individual chunks when transferring snapshots
     ///
     /// Default: `default_chunk_size()` (typically 1MB)
@@ -468,6 +471,7 @@ impl Default for SnapshotConfig {
             snapshot_cool_down_since_last_check: default_snapshot_cool_down_since_last_check(),
             cleanup_retain_count: default_cleanup_retain_count(),
             snapshots_dir: default_snapshots_dir(),
+            snapshots_dir_prefix: default_snapshots_dir_prefix(),
             chunk_size: default_chunk_size(),
             retained_log_entries: default_retained_log_entries(),
             sender_yield_every_n_chunks: default_sender_yield_every_n_chunks(),
@@ -573,6 +577,10 @@ fn default_cleanup_retain_count() -> u64 {
 fn default_snapshots_dir() -> PathBuf {
     PathBuf::from("/tmp/snapshots")
 }
+/// Default snapshots directory prefix
+fn default_snapshots_dir_prefix() -> String {
+    "snapshot-".to_string()
+}
 
 /// 1KB chunks by default
 fn default_chunk_size() -> usize {
@@ -696,7 +704,7 @@ fn default_stale_check_interval() -> Duration {
 ///
 /// **Note:** Both strategies now fully load all log entries from disk into memory at startup.
 /// The in-memory `SkipMap` serves as the primary data structure for reads in all modes.
-#[doc = include_str!("../docs/architecture/raft-log-persistence-architecture.md")]
+#[doc = include_str!("../../../d-engine-docs/src/docs/architecture/raft-log-persistence-architecture.md")]
 #[derive(Clone, Debug, Serialize, Deserialize, PartialEq)]
 pub enum PersistenceStrategy {
     /// Disk-first persistence strategy.
@@ -926,29 +934,31 @@ impl ReadConsistencyConfig {
     }
 }
 
-impl From<crate::proto::client::ReadConsistencyPolicy> for ReadConsistencyPolicy {
-    fn from(proto_policy: crate::proto::client::ReadConsistencyPolicy) -> Self {
+impl From<d_engine_proto::client::ReadConsistencyPolicy> for ReadConsistencyPolicy {
+    fn from(proto_policy: d_engine_proto::client::ReadConsistencyPolicy) -> Self {
         match proto_policy {
-            crate::proto::client::ReadConsistencyPolicy::LeaseRead => Self::LeaseRead,
-            crate::proto::client::ReadConsistencyPolicy::LinearizableRead => Self::LinearizableRead,
-            crate::proto::client::ReadConsistencyPolicy::EventualConsistency => {
+            d_engine_proto::client::ReadConsistencyPolicy::LeaseRead => Self::LeaseRead,
+            d_engine_proto::client::ReadConsistencyPolicy::LinearizableRead => {
+                Self::LinearizableRead
+            }
+            d_engine_proto::client::ReadConsistencyPolicy::EventualConsistency => {
                 Self::EventualConsistency
             }
         }
     }
 }
 
-impl From<ReadConsistencyPolicy> for crate::proto::client::ReadConsistencyPolicy {
+impl From<ReadConsistencyPolicy> for d_engine_proto::client::ReadConsistencyPolicy {
     fn from(config_policy: ReadConsistencyPolicy) -> Self {
         match config_policy {
             ReadConsistencyPolicy::LeaseRead => {
-                crate::proto::client::ReadConsistencyPolicy::LeaseRead
+                d_engine_proto::client::ReadConsistencyPolicy::LeaseRead
             }
             ReadConsistencyPolicy::LinearizableRead => {
-                crate::proto::client::ReadConsistencyPolicy::LinearizableRead
+                d_engine_proto::client::ReadConsistencyPolicy::LinearizableRead
             }
             ReadConsistencyPolicy::EventualConsistency => {
-                crate::proto::client::ReadConsistencyPolicy::EventualConsistency
+                d_engine_proto::client::ReadConsistencyPolicy::EventualConsistency
             }
         }
     }
diff --git a/src/config/raft_test.rs b/d-engine-core/src/config/raft_test.rs
similarity index 100%
rename from src/config/raft_test.rs
rename to d-engine-core/src/config/raft_test.rs
diff --git a/src/config/retry.rs b/d-engine-core/src/config/retry.rs
similarity index 100%
rename from src/config/retry.rs
rename to d-engine-core/src/config/retry.rs
diff --git a/src/config/security.rs b/d-engine-core/src/config/security.rs
similarity index 100%
rename from src/config/security.rs
rename to d-engine-core/src/config/security.rs
diff --git a/src/config/tls.rs b/d-engine-core/src/config/tls.rs
similarity index 100%
rename from src/config/tls.rs
rename to d-engine-core/src/config/tls.rs
diff --git a/src/config/tls_test.rs b/d-engine-core/src/config/tls_test.rs
similarity index 98%
rename from src/config/tls_test.rs
rename to d-engine-core/src/config/tls_test.rs
index 0f0029d7..3fb4ff85 100644
--- a/src/config/tls_test.rs
+++ b/d-engine-core/src/config/tls_test.rs
@@ -1,7 +1,7 @@
 use tempfile::NamedTempFile;
 
-use crate::config::tls::TlsConfig;
 use crate::Error;
+use crate::config::tls::TlsConfig;
 
 #[test]
 fn test_tls_config_default_values() {
@@ -88,9 +88,11 @@ fn test_validate_self_signed_with_cert_paths_should_fail() {
 
     let error = result.unwrap_err();
     assert!(matches!(error, Error::Config(_)));
-    assert!(error
-        .to_string()
-        .contains("Cannot specify certificate paths with generate_self_signed_certificates=true"));
+    assert!(
+        error.to_string().contains(
+            "Cannot specify certificate paths with generate_self_signed_certificates=true"
+        )
+    );
 }
 
 #[test]
diff --git a/src/core/election/election_handler.rs b/d-engine-core/src/election/election_handler.rs
similarity index 84%
rename from src/core/election/election_handler.rs
rename to d-engine-core/src/election/election_handler.rs
index e2b6b085..963b26aa 100644
--- a/src/core/election/election_handler.rs
+++ b/d-engine-core/src/election/election_handler.rs
@@ -9,15 +9,6 @@ use tracing::trace;
 use tracing::warn;
 
 use super::ElectionCore;
-use crate::alias::MOF;
-use crate::alias::ROF;
-use crate::alias::TROF;
-use crate::cluster::is_majority;
-use crate::if_higher_term_found;
-use crate::is_target_log_more_recent;
-use crate::proto::common::LogId;
-use crate::proto::election::VoteRequest;
-use crate::proto::election::VotedFor;
 use crate::ElectionError;
 use crate::Membership;
 use crate::RaftLog;
@@ -26,6 +17,15 @@ use crate::Result;
 use crate::StateUpdate;
 use crate::Transport;
 use crate::TypeConfig;
+use crate::alias::MOF;
+use crate::alias::ROF;
+use crate::alias::TROF;
+use crate::cluster::is_majority;
+use crate::if_higher_term_found;
+use crate::is_target_log_more_recent;
+use d_engine_proto::common::LogId;
+use d_engine_proto::server::election::VoteRequest;
+use d_engine_proto::server::election::VotedFor;
 
 #[derive(Clone)]
 pub struct ElectionHandler<T: TypeConfig> {
@@ -188,60 +188,55 @@ where
         };
 
         // Check if we should grant the vote
-        let grant_vote =
-            if request.term < current_term {
-                // Request term is lower, cannot grant vote
-                trace!(
+        let grant_vote = if request.term < current_term {
+            // Request term is lower, cannot grant vote
+            trace!(
                 "[node-{} -> node-{}] Request term is lower, cannot grant vote. VoteRequest = {:?}",
                 request.candidate_id, self.my_id, &request
             );
 
-                false
-            } else {
-                // Request term is >= current term
-                // Check log completeness
-                if !is_target_log_more_recent(
-                    last_logid.index,
-                    last_logid.term,
+            false
+        } else {
+            // Request term is >= current term
+            // Check log completeness
+            if !is_target_log_more_recent(
+                last_logid.index,
+                last_logid.term,
+                request.last_log_index,
+                request.last_log_term,
+            ) {
+                trace!(
+                    "node-{}: last_log_index({}(t:{})) -> node-{}: last_log_index({}(t:{}))",
+                    request.candidate_id,
                     request.last_log_index,
                     request.last_log_term,
-                ) {
+                    self.my_id,
+                    last_logid.index,
+                    last_logid.term
+                );
+
+                false
+            } else {
+                // Check if already voted for someone else in this term
+                if let Some(voted_for) = new_voted_for_option {
                     trace!(
-                        "node-{}: last_log_index({}(t:{})) -> node-{}: last_log_index({}(t:{}))",
-                        request.candidate_id,
-                        request.last_log_index,
-                        request.last_log_term,
-                        self.my_id,
-                        last_logid.index,
-                        last_logid.term
+                        "[node-{} -> node-{}] node-{} current vote: {:?}",
+                        request.candidate_id, self.my_id, self.my_id, &voted_for
                     );
-
-                    false
+                    // If already voted for someone else, cannot grant vote unless it's the same
+                    // candidate
+                    voted_for.voted_for_term == request.term
+                        && voted_for.voted_for_id == request.candidate_id
                 } else {
-                    // Check if already voted for someone else in this term
-                    if let Some(voted_for) = new_voted_for_option {
-                        trace!(
-                            "[node-{} -> node-{}] node-{} current vote: {:?}",
-                            request.candidate_id,
-                            self.my_id,
-                            self.my_id,
-                            &voted_for
-                        );
-                        // If already voted for someone else, cannot grant vote unless it's the same
-                        // candidate
-                        voted_for.voted_for_term == request.term
-                            && voted_for.voted_for_id == request.candidate_id
-                    } else {
-                        trace!(
-                            "node-{} vote for node-{} successfully!",
-                            self.my_id,
-                            request.candidate_id,
-                        );
-
-                        true
-                    }
+                    trace!(
+                        "node-{} vote for node-{} successfully!",
+                        self.my_id, request.candidate_id,
+                    );
+
+                    true
                 }
-            };
+            }
+        };
 
         if grant_vote {
             new_voted_for = Some(VotedFor {
@@ -250,14 +245,12 @@ where
             });
             trace!(
                 "node-{} -> node-{} successfully!",
-                request.candidate_id,
-                self.my_id,
+                request.candidate_id, self.my_id,
             );
         } else {
             trace!(
                 "node-{} -> node-{} failed!",
-                request.candidate_id,
-                self.my_id,
+                request.candidate_id, self.my_id,
             );
         }
 
@@ -323,7 +316,7 @@ impl<T> ElectionHandler<T>
 where
     T: TypeConfig,
 {
-    pub(crate) fn new(my_id: u32) -> Self {
+    pub fn new(my_id: u32) -> Self {
         Self {
             my_id,
             _phantom: PhantomData,
diff --git a/src/core/election/mod.rs b/d-engine-core/src/election/mod.rs
similarity index 92%
rename from src/core/election/mod.rs
rename to d-engine-core/src/election/mod.rs
index a23e1e2b..d2af994d 100644
--- a/src/core/election/mod.rs
+++ b/d-engine-core/src/election/mod.rs
@@ -7,25 +7,20 @@
 mod election_handler;
 pub use election_handler::*;
 
-#[cfg(test)]
-mod election_handler_test;
-
 use std::sync::Arc;
 
-///--------------------------------------
-/// Trait Definition
-#[cfg(test)]
+#[cfg(any(test, feature = "test-utils"))]
 use mockall::automock;
 use tonic::async_trait;
 
-use crate::alias::MOF;
-use crate::alias::ROF;
-use crate::alias::TROF;
-use crate::proto::election::VoteRequest;
-use crate::proto::election::VotedFor;
 use crate::RaftNodeConfig;
 use crate::Result;
 use crate::TypeConfig;
+use crate::alias::MOF;
+use crate::alias::ROF;
+use crate::alias::TROF;
+use d_engine_proto::server::election::VoteRequest;
+use d_engine_proto::server::election::VotedFor;
 
 /// State transition data for election outcomes
 #[derive(Debug)]
@@ -36,7 +31,7 @@ pub struct StateUpdate {
     pub new_voted_for: Option<VotedFor>,
 }
 
-#[cfg_attr(test, automock)]
+#[cfg_attr(any(test, feature = "test-utils"), automock)]
 #[async_trait]
 pub trait ElectionCore<T>: Send + Sync + 'static
 where
diff --git a/src/errors.rs b/d-engine-core/src/errors.rs
similarity index 100%
rename from src/errors.rs
rename to d-engine-core/src/errors.rs
diff --git a/d-engine-core/src/errors_test.rs b/d-engine-core/src/errors_test.rs
new file mode 100644
index 00000000..1d01102d
--- /dev/null
+++ b/d-engine-core/src/errors_test.rs
@@ -0,0 +1,482 @@
+use std::{path::PathBuf, time::Duration};
+
+use super::*;
+
+#[test]
+fn test_error_fatal() {
+    let err = Error::Fatal("critical failure".to_string());
+    assert_eq!(err.to_string(), "Fatal error: critical failure");
+}
+
+#[test]
+fn test_consensus_error_role_violation() {
+    let err = ConsensusError::RoleViolation {
+        current_role: "Follower",
+        required_role: "Leader",
+        context: "Cannot accept write requests".to_string(),
+    };
+    let msg = err.to_string();
+    assert!(msg.contains("Follower"));
+    assert!(msg.contains("Leader"));
+}
+
+#[test]
+fn test_state_transition_error_not_enough_votes() {
+    let err = StateTransitionError::NotEnoughVotes;
+    assert_eq!(err.to_string(), "Not enough votes to transition to leader.");
+}
+
+#[test]
+fn test_state_transition_error_invalid_transition() {
+    let err = StateTransitionError::InvalidTransition;
+    assert_eq!(err.to_string(), "Invalid state transition.");
+}
+
+#[test]
+fn test_state_transition_error_lock_error() {
+    let err = StateTransitionError::LockError;
+    assert_eq!(err.to_string(), "Lock error.");
+}
+
+#[test]
+fn test_network_error_service_unavailable() {
+    let err = NetworkError::ServiceUnavailable("node down".to_string());
+    assert_eq!(err.to_string(), "Service unavailable: node down");
+}
+
+#[test]
+fn test_network_error_timeout() {
+    let err = NetworkError::Timeout {
+        node_id: 42,
+        duration: Duration::from_secs(5),
+    };
+    let msg = err.to_string();
+    assert!(msg.contains("42"));
+    assert!(msg.contains("5s"));
+}
+
+#[test]
+fn test_network_error_empty_peer_list() {
+    let err = NetworkError::EmptyPeerList {
+        request_type: "AppendEntries",
+    };
+    let msg = err.to_string();
+    assert!(msg.contains("AppendEntries"));
+}
+
+#[test]
+fn test_network_error_signal_send_failed() {
+    let err = NetworkError::SingalSendFailed("channel closed".to_string());
+    let msg = err.to_string();
+    assert!(msg.contains("channel closed"));
+}
+
+#[test]
+fn test_storage_error_data_corruption() {
+    let err = StorageError::DataCorruption {
+        location: "raft_log_entry_42".to_string(),
+    };
+    let msg = err.to_string();
+    assert!(msg.contains("raft_log_entry_42"));
+}
+
+#[test]
+fn test_storage_error_path_error() {
+    let io_err = std::io::Error::new(std::io::ErrorKind::NotFound, "file not found");
+    let err = StorageError::PathError {
+        path: PathBuf::from("/data/raft.db"),
+        source: io_err,
+    };
+    let msg = err.to_string();
+    assert!(msg.contains("/data/raft.db"));
+}
+
+#[test]
+fn test_id_allocation_error_overflow() {
+    let err = IdAllocationError::Overflow {
+        start: 100,
+        end: 50,
+    };
+    let msg = err.to_string();
+    assert!(msg.contains("100"));
+    assert!(msg.contains("50"));
+}
+
+#[test]
+fn test_id_allocation_error_invalid_range() {
+    let err = IdAllocationError::InvalidRange { start: 10, end: 5 };
+    let msg = err.to_string();
+    assert!(msg.contains("10"));
+    assert!(msg.contains("5"));
+}
+
+#[test]
+fn test_id_allocation_error_no_ids_available() {
+    let err = IdAllocationError::NoIdsAvailable;
+    let msg = err.to_string();
+    assert!(msg.contains("IDs") || msg.contains("available"));
+}
+
+#[test]
+fn test_file_error_not_found() {
+    let err = FileError::NotFound("/path/to/file".to_string());
+    let msg = err.to_string();
+    assert!(msg.contains("/path/to/file"));
+}
+
+#[test]
+fn test_file_error_is_directory() {
+    let err = FileError::IsDirectory("/path/to/dir".to_string());
+    let msg = err.to_string();
+    assert!(msg.contains("/path/to/dir"));
+}
+
+#[test]
+fn test_file_error_permission_denied() {
+    let err = FileError::PermissionDenied("/restricted/file".to_string());
+    let msg = err.to_string();
+    assert!(msg.contains("/restricted/file"));
+}
+
+#[test]
+fn test_file_error_invalid_gzip_header() {
+    let err = FileError::InvalidGzipHeader("header mismatch".to_string());
+    let msg = err.to_string();
+    assert!(msg.contains("header mismatch"));
+}
+
+#[test]
+fn test_file_error_too_small() {
+    let err = FileError::TooSmall(42);
+    let msg = err.to_string();
+    assert!(msg.contains("42"));
+}
+
+#[test]
+fn test_convert_error_invalid_length() {
+    let err = ConvertError::InvalidLength(4);
+    let msg = err.to_string();
+    assert!(msg.contains("4"));
+    assert!(msg.contains("8"));
+}
+
+#[test]
+fn test_convert_error_conversion_failure() {
+    let err = ConvertError::ConversionFailure("Cannot convert to u64".to_string());
+    let msg = err.to_string();
+    assert!(msg.contains("Cannot convert to u64"));
+}
+
+#[test]
+fn test_write_send_error_not_leader() {
+    let err = WriteSendError::NotLeader;
+    let msg = err.to_string();
+    assert!(msg.contains("leader"));
+}
+
+#[test]
+fn test_write_send_error_payload_exceeded() {
+    let err = WriteSendError::PayloadExceeded;
+    let msg = err.to_string();
+    assert!(msg.contains("large") || msg.contains("Payload"));
+}
+
+#[test]
+fn test_write_send_error_unreachable() {
+    let err = WriteSendError::Unreachable;
+    let msg = err.to_string();
+    assert!(msg.contains("unreachable"));
+}
+
+#[test]
+fn test_system_error_server_unavailable() {
+    let err = SystemError::ServerUnavailable;
+    let msg = err.to_string();
+    assert!(msg.contains("unavailable") || msg.contains("server"));
+}
+
+#[test]
+fn test_election_error_higher_term() {
+    let err = ElectionError::HigherTerm(10);
+    let msg = err.to_string();
+    assert!(msg.contains("10"));
+}
+
+#[test]
+fn test_election_error_term_conflict() {
+    let err = ElectionError::TermConflict {
+        current: 5,
+        received: 3,
+    };
+    let msg = err.to_string();
+    assert!(msg.contains("5"));
+    assert!(msg.contains("3"));
+}
+
+#[test]
+fn test_election_error_log_conflict() {
+    let err = ElectionError::LogConflict {
+        index: 100,
+        expected_term: 5,
+        actual_term: 4,
+    };
+    let msg = err.to_string();
+    assert!(msg.contains("100"));
+    assert!(msg.contains("5"));
+    assert!(msg.contains("4"));
+}
+
+#[test]
+fn test_election_error_quorum_failure() {
+    let err = ElectionError::QuorumFailure {
+        required: 3,
+        succeed: 2,
+    };
+    let msg = err.to_string();
+    assert!(msg.contains("3"));
+    assert!(msg.contains("2"));
+}
+
+#[test]
+fn test_election_error_no_voting_member_found() {
+    let err = ElectionError::NoVotingMemberFound { candidate_id: 42 };
+    let msg = err.to_string();
+    assert!(msg.contains("42"));
+}
+
+#[test]
+fn test_replication_error_higher_term() {
+    let err = ReplicationError::HigherTerm(15);
+    let msg = err.to_string();
+    assert!(msg.contains("15"));
+}
+
+#[test]
+fn test_replication_error_quorum_not_reached() {
+    let err = ReplicationError::QuorumNotReached;
+    let msg = err.to_string();
+    assert!(msg.contains("Quorum") && msg.contains("replication"));
+}
+
+#[test]
+fn test_replication_error_node_unreachable() {
+    let err = ReplicationError::NodeUnreachable { node_id: 123 };
+    let msg = err.to_string();
+    assert!(msg.contains("123"));
+}
+
+#[test]
+fn test_replication_error_log_conflict() {
+    let err = ReplicationError::LogConflict {
+        index: 50,
+        expected_term: 3,
+        actual_term: 2,
+    };
+    let msg = err.to_string();
+    assert!(msg.contains("50"));
+    assert!(msg.contains("3"));
+    assert!(msg.contains("2"));
+}
+
+#[test]
+fn test_replication_error_not_leader() {
+    let err = ReplicationError::NotLeader { leader_id: Some(1) };
+    let msg = err.to_string();
+    assert!(msg.contains("1"));
+}
+
+#[test]
+fn test_membership_error_not_leader() {
+    let err = MembershipError::NotLeader;
+    let msg = err.to_string();
+    assert!(msg.contains("leader"));
+}
+
+#[test]
+fn test_membership_error_no_leader_found() {
+    let err = MembershipError::NoLeaderFound;
+    let msg = err.to_string();
+    assert!(msg.contains("leader"));
+}
+
+#[test]
+fn test_membership_error_node_already_exists() {
+    let err = MembershipError::NodeAlreadyExists(42);
+    let msg = err.to_string();
+    assert!(msg.contains("42"));
+}
+
+#[test]
+fn test_membership_error_invalid_promotion() {
+    let err = MembershipError::InvalidPromotion {
+        node_id: 5,
+        role: 1, // Use i32 instead of String
+    };
+    let msg = err.to_string();
+    assert!(msg.contains("5"));
+    assert!(msg.contains("1"));
+}
+
+#[test]
+fn test_membership_error_remove_node_is_leader() {
+    let err = MembershipError::RemoveNodeIsLeader(3);
+    let msg = err.to_string();
+    assert!(msg.contains("3"));
+}
+
+#[test]
+fn test_membership_error_no_metadata_found() {
+    let err = MembershipError::NoMetadataFoundForNode { node_id: 99 };
+    let msg = err.to_string();
+    assert!(msg.contains("99"));
+}
+
+#[test]
+fn test_snapshot_error_rejected() {
+    let err = SnapshotError::Rejected { last_chunk: 42 };
+    let msg = err.to_string();
+    assert!(msg.contains("42"));
+}
+
+#[test]
+fn test_snapshot_error_checksum_mismatch() {
+    let err = SnapshotError::ChecksumMismatch;
+    let msg = err.to_string();
+    assert!(msg.contains("checksum") && msg.contains("mismatch"));
+}
+
+#[test]
+fn test_snapshot_error_invalid_snapshot() {
+    let err = SnapshotError::InvalidSnapshot;
+    let msg = err.to_string();
+    assert!(msg.contains("snapshot") || msg.contains("Invalid"));
+}
+
+#[test]
+fn test_snapshot_error_incomplete_snapshot() {
+    let err = SnapshotError::IncompleteSnapshot;
+    let msg = err.to_string();
+    assert!(msg.contains("snapshot") || msg.contains("Incomplete"));
+}
+
+// Test From trait implementations for error conversions
+#[test]
+fn test_from_network_error_to_error() {
+    let network_err = NetworkError::ServiceUnavailable("test".to_string());
+    let err: Error = network_err.into();
+    assert!(matches!(err, Error::System(SystemError::Network(_))));
+}
+
+#[test]
+fn test_from_storage_error_to_error() {
+    let storage_err = StorageError::LogStorage("test error".to_string());
+    let err: Error = storage_err.into();
+    assert!(matches!(err, Error::System(SystemError::Storage(_))));
+}
+
+#[test]
+fn test_from_state_transition_error_to_error() {
+    let state_err = StateTransitionError::NotEnoughVotes;
+    let err: Error = state_err.into();
+    assert!(matches!(
+        err,
+        Error::Consensus(ConsensusError::StateTransition(_))
+    ));
+}
+
+#[test]
+fn test_from_election_error_to_error() {
+    let election_err = ElectionError::Failed("election timeout".to_string());
+    let err: Error = election_err.into();
+    assert!(matches!(err, Error::Consensus(ConsensusError::Election(_))));
+}
+
+#[test]
+fn test_from_replication_error_to_error() {
+    let replication_err = ReplicationError::QuorumNotReached;
+    let err: Error = replication_err.into();
+    assert!(matches!(
+        err,
+        Error::Consensus(ConsensusError::Replication(_))
+    ));
+}
+
+#[test]
+fn test_from_membership_error_to_error() {
+    let membership_err = MembershipError::NotLeader;
+    let err: Error = membership_err.into();
+    assert!(matches!(
+        err,
+        Error::Consensus(ConsensusError::Membership(_))
+    ));
+}
+
+#[test]
+fn test_from_snapshot_error_to_error() {
+    let snapshot_err = SnapshotError::InvalidSnapshot;
+    let err: Error = snapshot_err.into();
+    assert!(matches!(err, Error::Consensus(ConsensusError::Snapshot(_))));
+}
+
+#[test]
+fn test_from_io_error_to_error() {
+    let io_err = std::io::Error::new(std::io::ErrorKind::NotFound, "test");
+    let err: Error = io_err.into();
+    assert!(matches!(err, Error::System(SystemError::Storage(_))));
+}
+
+#[test]
+fn test_from_id_allocation_error_to_error() {
+    let id_err = IdAllocationError::NoIdsAvailable;
+    let err: Error = id_err.into();
+    assert!(matches!(err, Error::System(SystemError::Storage(_))));
+}
+
+#[test]
+fn test_error_display_formatting() {
+    let err = Error::Fatal("system failure".to_string());
+    let display = format!("{err}");
+    assert_eq!(display, "Fatal error: system failure");
+}
+
+#[test]
+fn test_consensus_error_nesting() {
+    let state_err = StateTransitionError::InvalidTransition;
+    let consensus_err: ConsensusError = state_err.into();
+    let top_err: Error = consensus_err.into();
+
+    assert!(matches!(
+        top_err,
+        Error::Consensus(ConsensusError::StateTransition(
+            StateTransitionError::InvalidTransition
+        ))
+    ));
+}
+
+#[test]
+fn test_network_error_connect_error() {
+    let err = NetworkError::ConnectError("connection refused".to_string());
+    let msg = err.to_string();
+    assert!(msg.contains("connection refused"));
+}
+
+#[test]
+fn test_network_error_invalid_uri() {
+    let err = NetworkError::InvalidURI("malformed://uri".to_string());
+    let msg = err.to_string();
+    assert!(msg.contains("malformed://uri"));
+}
+
+#[test]
+fn test_system_error_general_server() {
+    let err = SystemError::GeneralServer("server error".to_string());
+    let msg = err.to_string();
+    assert!(msg.contains("server error"));
+}
+
+#[test]
+fn test_system_error_node_start_failed_with_message() {
+    let err = SystemError::NodeStartFailed("initialization failed".to_string());
+    let msg = err.to_string();
+    assert!(msg.contains("initialization failed"));
+}
diff --git a/src/core/event.rs b/d-engine-core/src/event.rs
similarity index 73%
rename from src/core/event.rs
rename to d-engine-core/src/event.rs
index 65b4198e..0dabb569 100644
--- a/src/core/event.rs
+++ b/d-engine-core/src/event.rs
@@ -2,42 +2,42 @@ use std::path::PathBuf;
 
 use tonic::Status;
 
-use crate::proto::client::ClientReadRequest;
-use crate::proto::client::ClientResponse;
-use crate::proto::client::ClientWriteRequest;
-use crate::proto::cluster::ClusterConfChangeRequest;
-use crate::proto::cluster::ClusterConfUpdateResponse;
-use crate::proto::cluster::ClusterMembership;
-use crate::proto::cluster::JoinRequest;
-use crate::proto::cluster::JoinResponse;
-use crate::proto::cluster::LeaderDiscoveryRequest;
-use crate::proto::cluster::LeaderDiscoveryResponse;
-use crate::proto::cluster::MetadataRequest;
-use crate::proto::common::LogId;
-use crate::proto::election::VoteRequest;
-use crate::proto::election::VoteResponse;
-use crate::proto::replication::AppendEntriesRequest;
-use crate::proto::replication::AppendEntriesResponse;
-use crate::proto::storage::PurgeLogRequest;
-use crate::proto::storage::PurgeLogResponse;
-use crate::proto::storage::SnapshotAck;
-use crate::proto::storage::SnapshotChunk;
-use crate::proto::storage::SnapshotMetadata;
-use crate::proto::storage::SnapshotResponse;
 use crate::MaybeCloneOneshotSender;
 use crate::Result;
 use crate::StreamResponseSender;
+use d_engine_proto::client::ClientReadRequest;
+use d_engine_proto::client::ClientResponse;
+use d_engine_proto::client::ClientWriteRequest;
+use d_engine_proto::common::LogId;
+use d_engine_proto::server::cluster::ClusterConfChangeRequest;
+use d_engine_proto::server::cluster::ClusterConfUpdateResponse;
+use d_engine_proto::server::cluster::ClusterMembership;
+use d_engine_proto::server::cluster::JoinRequest;
+use d_engine_proto::server::cluster::JoinResponse;
+use d_engine_proto::server::cluster::LeaderDiscoveryRequest;
+use d_engine_proto::server::cluster::LeaderDiscoveryResponse;
+use d_engine_proto::server::cluster::MetadataRequest;
+use d_engine_proto::server::election::VoteRequest;
+use d_engine_proto::server::election::VoteResponse;
+use d_engine_proto::server::replication::AppendEntriesRequest;
+use d_engine_proto::server::replication::AppendEntriesResponse;
+use d_engine_proto::server::storage::PurgeLogRequest;
+use d_engine_proto::server::storage::PurgeLogResponse;
+use d_engine_proto::server::storage::SnapshotAck;
+use d_engine_proto::server::storage::SnapshotChunk;
+use d_engine_proto::server::storage::SnapshotMetadata;
+use d_engine_proto::server::storage::SnapshotResponse;
 
 #[derive(Debug, Clone)]
-pub(crate) struct NewCommitData {
-    pub(crate) new_commit_index: u64,
-    pub(crate) role: i32,
-    pub(crate) current_term: u64,
+pub struct NewCommitData {
+    pub new_commit_index: u64,
+    pub role: i32,
+    pub current_term: u64,
 }
 
 #[derive(Debug)]
 #[allow(dead_code)]
-pub(crate) enum RoleEvent {
+pub enum RoleEvent {
     BecomeFollower(Option<u32>), // BecomeFollower(Option<leader_id>)
     BecomeCandidate,
     BecomeLeader,
@@ -49,7 +49,7 @@ pub(crate) enum RoleEvent {
 }
 
 #[derive(Debug)]
-pub(crate) enum RaftEvent {
+pub enum RaftEvent {
     ReceiveVoteRequest(
         VoteRequest,
         MaybeCloneOneshotSender<std::result::Result<VoteResponse, Status>>,
@@ -120,10 +120,10 @@ pub(crate) enum RaftEvent {
     PromoteReadyLearners,
 }
 
-#[cfg(test)]
-#[cfg_attr(test, derive(Debug, Clone))]
+#[cfg(any(test, feature = "test-utils"))]
+#[cfg_attr(any(test, feature = "test-utils"), derive(Debug, Clone))]
 #[allow(unused)]
-pub(crate) enum TestEvent {
+pub enum TestEvent {
     ReceiveVoteRequest(VoteRequest),
 
     ClusterConf(MetadataRequest),
@@ -158,8 +158,8 @@ pub(crate) enum TestEvent {
     PromoteReadyLearners,
 }
 
-#[cfg(test)]
-pub(crate) fn raft_event_to_test_event(event: &RaftEvent) -> TestEvent {
+#[cfg(any(test, feature = "test-utils"))]
+pub fn raft_event_to_test_event(event: &RaftEvent) -> TestEvent {
     match event {
         RaftEvent::ReceiveVoteRequest(req, _) => TestEvent::ReceiveVoteRequest(*req),
         RaftEvent::ClusterConf(req, _) => TestEvent::ClusterConf(*req),
diff --git a/src/core/mod.rs b/d-engine-core/src/lib.rs
similarity index 65%
rename from src/core/mod.rs
rename to d-engine-core/src/lib.rs
index e03ae20a..b8247e53 100644
--- a/src/core/mod.rs
+++ b/d-engine-core/src/lib.rs
@@ -1,38 +1,61 @@
 mod commit_handler;
+pub mod config;
 mod election;
+mod errors;
 mod event;
+mod maybe_clone_oneshot;
+mod membership;
+mod network;
 mod purge;
 mod raft;
 mod raft_context;
 mod raft_role;
 mod replication;
 mod state_machine_handler;
+mod storage;
 mod timer;
+mod type_config;
+mod utils;
+
+pub use config::*;
+pub use errors::*;
+pub use event::*;
+pub use membership::*;
+pub use network::*;
+pub use raft::*;
+pub use storage::*;
+
+pub use commit_handler::*;
+pub use election::*;
+pub use maybe_clone_oneshot::*;
+pub use purge::*;
+pub use raft_context::*;
+pub use replication::*;
+pub use state_machine_handler::*;
 
-use bytes::Bytes;
-pub(crate) use commit_handler::*;
-pub(crate) use election::*;
-pub(crate) use event::*;
-pub(crate) use purge::*;
-pub(crate) use raft::*;
-pub(crate) use raft_context::*;
 #[doc(hidden)]
 pub use raft_role::*;
-pub(crate) use replication::*;
-pub(crate) use state_machine_handler::*;
+
+#[doc(hidden)]
+pub use utils::*;
+
 pub(crate) use timer::*;
-use tracing::instrument;
+#[doc(hidden)]
+pub use type_config::*;
 
-use crate::proto::common::entry_payload::Payload;
-use crate::proto::common::membership_change::Change;
-use crate::proto::common::EntryPayload;
-use crate::proto::common::MembershipChange;
-use crate::proto::common::Noop;
+#[cfg(test)]
+mod maybe_clone_oneshot_test;
 
 #[cfg(test)]
-mod raft_oneshot_test;
+mod errors_test;
 #[cfg(test)]
-mod raft_test;
+mod raft_oneshot_test;
+
+#[cfg(any(test, feature = "test-utils"))]
+pub mod test_utils;
+
+#[cfg(any(test, feature = "test-utils"))]
+pub use test_utils::*;
 
 /// In raft, during any Leader to Peer communication,
 ///     if received response term is bigger than Leader's,
@@ -63,7 +86,7 @@ pub(crate) fn if_higher_term_found(
 /// entries in the  logs. If the logs have last entries with different terms, then the log with the
 /// later term is more up-to-date. If the logs end with the same term, then whichever log is longer
 /// is more up-to-date.
-#[instrument]
+#[tracing::instrument]
 pub(crate) fn is_target_log_more_recent(
     my_last_log_index: u64,
     my_last_log_term: u64,
@@ -80,24 +103,3 @@ pub enum QuorumStatus {
     LostQuorum,   // Unable to obtain majority
     NetworkError, // Network problem (can be retried)
 }
-
-impl EntryPayload {
-    pub fn command(command: Bytes) -> Self {
-        Self {
-            payload: Some(Payload::Command(command)),
-        }
-    }
-    pub fn noop() -> Self {
-        Self {
-            payload: Some(Payload::Noop(Noop {})),
-        }
-    }
-
-    pub fn config(change: Change) -> Self {
-        Self {
-            payload: Some(Payload::Config(MembershipChange {
-                change: Some(change),
-            })),
-        }
-    }
-}
diff --git a/src/node/type_config/maybe_clone_oneshot.rs b/d-engine-core/src/maybe_clone_oneshot.rs
similarity index 83%
rename from src/node/type_config/maybe_clone_oneshot.rs
rename to d-engine-core/src/maybe_clone_oneshot.rs
index a1570235..921a2f8d 100644
--- a/src/node/type_config/maybe_clone_oneshot.rs
+++ b/d-engine-core/src/maybe_clone_oneshot.rs
@@ -17,12 +17,12 @@ use std::pin::Pin;
 use std::task::Context;
 use std::task::Poll;
 
-#[cfg(test)]
+#[cfg(any(test, feature = "test-utils"))]
 use tokio::sync::broadcast;
 use tokio::sync::oneshot;
 use tonic::Status;
 
-use crate::proto::storage::SnapshotChunk;
+use d_engine_proto::server::storage::SnapshotChunk;
 
 pub trait RaftOneshot<T: Send> {
     type Sender: Send + Sync;
@@ -31,13 +31,13 @@ pub trait RaftOneshot<T: Send> {
     fn new() -> (Self::Sender, Self::Receiver);
 }
 
-pub(crate) struct MaybeCloneOneshot;
+pub struct MaybeCloneOneshot;
 
-#[allow(dead_code)]
-pub(crate) struct MaybeCloneOneshotSender<T: Send> {
+pub struct MaybeCloneOneshotSender<T: Send> {
+    #[allow(dead_code)]
     inner: oneshot::Sender<T>,
 
-    #[cfg(test)]
+    #[cfg(any(test, feature = "test-utils"))]
     test_inner: Option<broadcast::Sender<T>>, // None for non-cloneable types
 }
 
@@ -50,14 +50,14 @@ impl<T: Send> Debug for MaybeCloneOneshotSender<T> {
     }
 }
 
-#[allow(dead_code)]
-pub(crate) struct MaybeCloneOneshotReceiver<T: Send> {
+pub struct MaybeCloneOneshotReceiver<T: Send> {
+    #[allow(dead_code)]
     inner: oneshot::Receiver<T>,
 
-    #[cfg(test)]
+    #[cfg(any(test, feature = "test-utils"))]
     test_inner: Option<broadcast::Receiver<T>>, // None for non-cloneable types
 }
-#[cfg(test)]
+#[cfg(any(test, feature = "test-utils"))]
 impl<T: Send> MaybeCloneOneshotSender<T> {
     pub fn send(
         &self,
@@ -72,7 +72,7 @@ impl<T: Send> MaybeCloneOneshotSender<T> {
     }
 }
 
-#[cfg(not(test))]
+#[cfg(not(any(test, feature = "test-utils")))]
 impl<T: Send> MaybeCloneOneshotSender<T> {
     pub fn send(
         self,
@@ -83,9 +83,9 @@ impl<T: Send> MaybeCloneOneshotSender<T> {
 }
 
 impl<T: Send + Clone> MaybeCloneOneshotReceiver<T> {
-    #[cfg(test)]
+    #[cfg(any(test, feature = "test-utils"))]
     pub async fn recv(&mut self) -> Result<T, broadcast::error::RecvError> {
-        if let Some(ref mut rx) = &mut self.test_inner {
+        if let Some(rx) = &mut self.test_inner {
             rx.recv().await
         } else {
             // Fallback for non-cloneable types
@@ -94,7 +94,7 @@ impl<T: Send + Clone> MaybeCloneOneshotReceiver<T> {
     }
 }
 
-#[cfg(not(test))]
+#[cfg(not(any(test, feature = "test-utils")))]
 impl<T: Send + Clone> Future for MaybeCloneOneshotReceiver<T> {
     type Output = Result<T, oneshot::error::RecvError>;
 
@@ -105,7 +105,7 @@ impl<T: Send + Clone> Future for MaybeCloneOneshotReceiver<T> {
         unsafe { self.map_unchecked_mut(|s| &mut s.inner) }.poll(cx)
     }
 }
-#[cfg(test)]
+#[cfg(any(test, feature = "test-utils"))]
 impl<T: Send + Clone> Future for MaybeCloneOneshotReceiver<T> {
     type Output = Result<T, broadcast::error::RecvError>;
 
@@ -116,7 +116,7 @@ impl<T: Send + Clone> Future for MaybeCloneOneshotReceiver<T> {
         let this = self.get_mut();
 
         // Using the recv method of tokio::sync::broadcast::Receiver
-        if let Some(ref mut rx) = &mut this.test_inner {
+        if let Some(rx) = &mut this.test_inner {
             match rx.try_recv() {
                 Ok(value) => Poll::Ready(Ok(value)),
                 Err(broadcast::error::TryRecvError::Empty) => {
@@ -138,7 +138,7 @@ impl<T: Send + Clone> Future for MaybeCloneOneshotReceiver<T> {
     }
 }
 
-#[cfg(test)]
+#[cfg(any(test, feature = "test-utils"))]
 impl<T: Send + Clone> Clone for MaybeCloneOneshotSender<T> {
     fn clone(&self) -> Self {
         let (sender, _) = oneshot::channel();
@@ -148,7 +148,7 @@ impl<T: Send + Clone> Clone for MaybeCloneOneshotSender<T> {
         }
     }
 }
-#[cfg(test)]
+#[cfg(any(test, feature = "test-utils"))]
 impl<T: Send + Clone> Clone for MaybeCloneOneshotReceiver<T> {
     fn clone(&self) -> Self {
         let (_, receiver) = oneshot::channel();
@@ -159,7 +159,7 @@ impl<T: Send + Clone> Clone for MaybeCloneOneshotReceiver<T> {
         }
     }
 }
-#[cfg(test)]
+#[cfg(any(test, feature = "test-utils"))]
 impl<T: Send + Clone> RaftOneshot<T> for MaybeCloneOneshot {
     type Sender = MaybeCloneOneshotSender<T>;
     type Receiver = MaybeCloneOneshotReceiver<T>;
@@ -180,7 +180,7 @@ impl<T: Send + Clone> RaftOneshot<T> for MaybeCloneOneshot {
     }
 }
 
-#[cfg(not(test))]
+#[cfg(not(any(test, feature = "test-utils")))]
 impl<T: Send> RaftOneshot<T> for MaybeCloneOneshot {
     type Sender = MaybeCloneOneshotSender<T>;
     type Receiver = MaybeCloneOneshotReceiver<T>;
@@ -190,12 +190,12 @@ impl<T: Send> RaftOneshot<T> for MaybeCloneOneshot {
         (
             MaybeCloneOneshotSender {
                 inner: tx,
-                #[cfg(test)]
+                #[cfg(any(test, feature = "test-utils"))]
                 test_inner: None,
             },
             MaybeCloneOneshotReceiver {
                 inner: rx,
-                #[cfg(test)]
+                #[cfg(any(test, feature = "test-utils"))]
                 test_inner: None,
             },
         )
@@ -203,10 +203,10 @@ impl<T: Send> RaftOneshot<T> for MaybeCloneOneshot {
 }
 
 #[derive(Debug)]
-pub(crate) struct StreamResponseSender {
+pub struct StreamResponseSender {
     inner: oneshot::Sender<std::result::Result<tonic::Streaming<SnapshotChunk>, Status>>,
 
-    #[cfg(test)]
+    #[cfg(any(test, feature = "test-utils"))]
     test_inner:
         Option<broadcast::Sender<std::result::Result<tonic::Streaming<SnapshotChunk>, Status>>>,
 }
@@ -220,7 +220,7 @@ impl StreamResponseSender {
         (
             Self {
                 inner: inner_tx,
-                #[cfg(test)]
+                #[cfg(any(test, feature = "test-utils"))]
                 test_inner: None,
             },
             inner_rx,
@@ -231,10 +231,10 @@ impl StreamResponseSender {
         self,
         value: std::result::Result<tonic::Streaming<SnapshotChunk>, Status>,
     ) -> Result<(), Box<std::result::Result<tonic::Streaming<SnapshotChunk>, Status>>> {
-        #[cfg(not(test))]
+        #[cfg(not(any(test, feature = "test-utils")))]
         return self.inner.send(value).map_err(Box::new);
 
-        #[cfg(test)]
+        #[cfg(any(test, feature = "test-utils"))]
         if let Some(tx) = self.test_inner {
             tx.send(value).map(|_| ()).map_err(|e| Box::new(e.0))
         } else {
diff --git a/d-engine-core/src/maybe_clone_oneshot_test.rs b/d-engine-core/src/maybe_clone_oneshot_test.rs
new file mode 100644
index 00000000..75746360
--- /dev/null
+++ b/d-engine-core/src/maybe_clone_oneshot_test.rs
@@ -0,0 +1,227 @@
+use crate::maybe_clone_oneshot::{MaybeCloneOneshot, RaftOneshot};
+use std::sync::Arc;
+use tokio::sync::Mutex;
+
+#[tokio::test]
+async fn test_oneshot_basic_send_recv() {
+    let (tx, mut rx) = MaybeCloneOneshot::new();
+    let value = 42;
+
+    tx.send(value).expect("Failed to send");
+    let received = rx.recv().await.expect("Failed to receive");
+
+    assert_eq!(received, value);
+}
+
+#[tokio::test]
+async fn test_oneshot_clone_sender() {
+    let (tx, mut rx) = MaybeCloneOneshot::new();
+    let tx_cloned = tx.clone();
+
+    let value = 100;
+    tx_cloned.send(value).expect("Failed to send");
+    let received = rx.recv().await.expect("Failed to receive");
+
+    assert_eq!(received, value);
+}
+
+#[tokio::test]
+async fn test_oneshot_clone_receiver() {
+    let (tx, rx) = MaybeCloneOneshot::new();
+    let mut rx_cloned = rx.clone();
+
+    let value = 123;
+    tx.send(value).expect("Failed to send");
+    let received = rx_cloned.recv().await.expect("Failed to receive");
+
+    assert_eq!(received, value);
+}
+
+#[tokio::test]
+async fn test_oneshot_multiple_clones() {
+    let (tx, rx1) = MaybeCloneOneshot::new();
+    let rx2 = rx1.clone();
+    let tx_cloned = tx.clone();
+
+    let value = 999;
+    tx_cloned.send(value).expect("Failed to send");
+
+    let mut rx1_mut = rx1;
+    let mut rx2_mut = rx2;
+    let received1 = rx1_mut.recv().await.expect("Failed to receive rx1");
+    let received2 = rx2_mut.recv().await.expect("Failed to receive rx2");
+
+    assert_eq!(received1, value);
+    assert_eq!(received2, value);
+}
+
+#[tokio::test]
+async fn test_oneshot_with_string() {
+    let (tx, mut rx) = MaybeCloneOneshot::new();
+    let value = "test_message".to_string();
+
+    tx.send(value.clone()).expect("Failed to send");
+    let received = rx.recv().await.expect("Failed to receive");
+
+    assert_eq!(received, value);
+}
+
+#[tokio::test]
+async fn test_oneshot_concurrent_receivers() {
+    let (tx, rx) = MaybeCloneOneshot::new();
+    let rx_clone1 = rx.clone();
+    let rx_clone2 = rx.clone();
+
+    let value = 555;
+    tx.send(value).expect("Failed to send");
+
+    let handle1 = tokio::spawn(async move {
+        let mut r = rx_clone1;
+        r.recv().await.expect("Failed in task 1")
+    });
+
+    let handle2 = tokio::spawn(async move {
+        let mut r = rx_clone2;
+        r.recv().await.expect("Failed in task 2")
+    });
+
+    let result1 = handle1.await.expect("Task 1 failed");
+    let result2 = handle2.await.expect("Task 2 failed");
+
+    assert_eq!(result1, value);
+    assert_eq!(result2, value);
+}
+
+#[tokio::test]
+async fn test_oneshot_with_vector() {
+    let (tx, mut rx) = MaybeCloneOneshot::new();
+    let value = vec![1, 2, 3, 4, 5];
+
+    tx.send(value.clone()).expect("Failed to send");
+    let received = rx.recv().await.expect("Failed to receive");
+
+    assert_eq!(received, value);
+}
+
+#[tokio::test]
+async fn test_oneshot_stress_multiple_sends() {
+    for i in 0..100 {
+        let (tx, mut rx) = MaybeCloneOneshot::new();
+        tx.send(i).expect("Failed to send");
+        let received = rx.recv().await.expect("Failed to receive");
+        assert_eq!(received, i);
+    }
+}
+
+#[tokio::test]
+async fn test_oneshot_clone_chain() {
+    let (tx, rx) = MaybeCloneOneshot::new();
+    let rx1 = rx.clone();
+    let rx2 = rx1.clone();
+    let mut rx3 = rx2.clone();
+
+    let value = 777;
+    tx.send(value).expect("Failed to send");
+
+    let received = rx3.recv().await.expect("Failed to receive");
+    assert_eq!(received, value);
+}
+
+#[tokio::test]
+async fn test_oneshot_sender_clone_and_send() {
+    let (tx, mut rx) = MaybeCloneOneshot::new();
+    let tx1 = tx.clone();
+    let tx2 = tx1.clone();
+
+    let value = 444;
+    tx2.send(value).expect("Failed to send");
+    let received = rx.recv().await.expect("Failed to receive");
+
+    assert_eq!(received, value);
+}
+
+#[tokio::test]
+async fn test_oneshot_with_custom_struct() {
+    #[derive(Debug, Clone, PartialEq)]
+    struct TestData {
+        id: u32,
+        name: String,
+    }
+
+    let (tx, mut rx) = MaybeCloneOneshot::new();
+    let value = TestData {
+        id: 42,
+        name: "test".to_string(),
+    };
+
+    tx.send(value.clone()).expect("Failed to send");
+    let received = rx.recv().await.expect("Failed to receive");
+
+    assert_eq!(received, value);
+    assert_eq!(received.id, 42);
+    assert_eq!(received.name, "test");
+}
+
+#[tokio::test]
+async fn test_oneshot_arc_shared_state() {
+    let (tx, mut rx) = MaybeCloneOneshot::new();
+    let shared_data = Arc::new(Mutex::new(vec![1, 2, 3]));
+    let shared_clone = Arc::clone(&shared_data);
+
+    tx.send(shared_clone).expect("Failed to send");
+    let received_arc = rx.recv().await.expect("Failed to receive");
+    let guard = received_arc.lock().await;
+
+    assert_eq!(guard.len(), 3);
+    assert_eq!(guard[0], 1);
+    assert_eq!(guard[1], 2);
+    assert_eq!(guard[2], 3);
+}
+
+#[tokio::test]
+async fn test_oneshot_receiver_as_future() {
+    let (tx, rx) = MaybeCloneOneshot::new();
+    let value = 333;
+
+    tokio::spawn(async move {
+        tokio::time::sleep(tokio::time::Duration::from_millis(10)).await;
+        tx.send(value).expect("Failed to send");
+    });
+
+    let received = rx.await.expect("Failed to receive");
+    assert_eq!(received, value);
+}
+
+#[tokio::test]
+async fn test_oneshot_with_zero() {
+    let (tx, mut rx) = MaybeCloneOneshot::new();
+    let value = 0;
+
+    tx.send(value).expect("Failed to send");
+    let received = rx.recv().await.expect("Failed to receive");
+
+    assert_eq!(received, value);
+}
+
+#[tokio::test]
+async fn test_oneshot_with_max_u64() {
+    let (tx, mut rx) = MaybeCloneOneshot::new();
+    let value = u64::MAX;
+
+    tx.send(value).expect("Failed to send");
+    let received = rx.recv().await.expect("Failed to receive");
+
+    assert_eq!(received, value);
+}
+
+#[tokio::test]
+async fn test_oneshot_empty_string() {
+    let (tx, mut rx) = MaybeCloneOneshot::new();
+    let value = String::new();
+
+    tx.send(value.clone()).expect("Failed to send");
+    let received = rx.recv().await.expect("Failed to receive");
+
+    assert_eq!(received, value);
+    assert!(received.is_empty());
+}
diff --git a/src/membership/mod.rs b/d-engine-core/src/membership.rs
similarity index 53%
rename from src/membership/mod.rs
rename to d-engine-core/src/membership.rs
index 5d50006d..deefde01 100644
--- a/src/membership/mod.rs
+++ b/d-engine-core/src/membership.rs
@@ -1,35 +1,28 @@
-mod membership_guard;
-mod raft_membership;
-pub(crate) use membership_guard::*;
-pub use raft_membership::*;
-
-#[cfg(test)]
-mod membership_guard_test;
-#[cfg(test)]
-mod raft_membership_test;
-
-#[cfg(test)]
+#[cfg(any(test, feature = "test-utils"))]
 use mockall::automock;
 use tonic::async_trait;
 use tonic::transport::Channel;
+use tracing::warn;
 
-use crate::proto::cluster::cluster_conf_update_response::ErrorCode;
-use crate::proto::cluster::ClusterConfChangeRequest;
-use crate::proto::cluster::ClusterConfUpdateResponse;
-use crate::proto::cluster::ClusterMembership;
-use crate::proto::common::NodeStatus;
+use crate::MembershipError;
 use crate::Result;
 use crate::TypeConfig;
+use d_engine_proto::common::MembershipChange;
+use d_engine_proto::common::NodeStatus;
+use d_engine_proto::server::cluster::ClusterConfChangeRequest;
+use d_engine_proto::server::cluster::ClusterConfUpdateResponse;
+use d_engine_proto::server::cluster::ClusterMembership;
+use d_engine_proto::server::cluster::NodeMeta;
 
 // Add connection type management in RpcPeerChannels
 #[derive(Clone, Debug, Eq, Hash, PartialEq)]
-pub(crate) enum ConnectionType {
+pub enum ConnectionType {
     Control, // Used for key operations such as elections/heartbeats
     Data,    // Used for log replication
     Bulk,    // Used for high-traffic operations such as snapshot transmission
 }
 impl ConnectionType {
-    pub(crate) fn all() -> Vec<ConnectionType> {
+    pub fn all() -> Vec<ConnectionType> {
         vec![
             ConnectionType::Control,
             ConnectionType::Data,
@@ -38,7 +31,7 @@ impl ConnectionType {
     }
 }
 
-#[cfg_attr(test, automock)]
+#[cfg_attr(any(test, feature = "test-utils"), automock)]
 #[async_trait]
 pub trait Membership<T>: Sync + Send + 'static
 where
@@ -46,22 +39,22 @@ where
 {
     /// All nodes (including itself)
     #[allow(unused)]
-    async fn members(&self) -> Vec<crate::proto::cluster::NodeMeta>;
+    async fn members(&self) -> Vec<NodeMeta>;
 
     /// All non-self nodes (including Syncing and Active)
     /// Note:
     /// Joining node has not start its Raft event processing engine yet.
-    async fn replication_peers(&self) -> Vec<crate::proto::cluster::NodeMeta>;
+    async fn replication_peers(&self) -> Vec<NodeMeta>;
 
     /// All non-self nodes in Active state
-    async fn voters(&self) -> Vec<crate::proto::cluster::NodeMeta>;
+    async fn voters(&self) -> Vec<NodeMeta>;
 
     /// All pending active nodes in Active state
     #[allow(unused)]
     async fn nodes_with_status(
         &self,
         status: NodeStatus,
-    ) -> Vec<crate::proto::cluster::NodeMeta>;
+    ) -> Vec<NodeMeta>;
 
     async fn get_node_status(
         &self,
@@ -147,7 +140,7 @@ where
     async fn retrieve_node_meta(
         &self,
         node_id: u32,
-    ) -> Option<crate::proto::cluster::NodeMeta>;
+    ) -> Option<NodeMeta>;
 
     /// Elegantly remove nodes
     async fn remove_node(
@@ -164,7 +157,7 @@ where
 
     /// Get all node status
     #[allow(unused)]
-    async fn get_all_nodes(&self) -> Vec<crate::proto::cluster::NodeMeta>;
+    async fn get_all_nodes(&self) -> Vec<NodeMeta>;
 
     /// Pre-warms connection cache for all replication peers
     async fn pre_warm_connections(&self) -> Result<()>;
@@ -183,7 +176,7 @@ where
     /// Apply committed configuration change
     async fn apply_config_change(
         &self,
-        change: crate::proto::common::MembershipChange,
+        change: MembershipChange,
     ) -> Result<()>;
 
     async fn notify_config_applied(
@@ -201,110 +194,31 @@ where
     ) -> Result<()>;
 }
 
-impl ClusterConfUpdateResponse {
-    /// Generate a successful response (full success)
-    pub(crate) fn success(
-        node_id: u32,
-        term: u64,
-        version: u64,
-    ) -> Self {
-        Self {
-            id: node_id,
-            term,
-            version,
-            success: true,
-            error_code: ErrorCode::None.into(),
-        }
-    }
-
-    /// Generate a failed response (Stale leader term)
-    pub(crate) fn higher_term(
-        node_id: u32,
-        term: u64,
-        version: u64,
-    ) -> Self {
-        Self {
-            id: node_id,
-            term,
-            version,
-            success: false,
-            error_code: ErrorCode::TermOutdated.into(),
-        }
-    }
-
-    /// Generate a failed response (Request sent to non-leader or an out-dated leader)
-    pub(crate) fn not_leader(
-        node_id: u32,
-        term: u64,
-        version: u64,
-    ) -> Self {
-        Self {
-            id: node_id,
-            term,
-            version,
-            success: false,
-            error_code: ErrorCode::NotLeader.into(),
-        }
-    }
-
-    /// Generate a failed response (Stale configuration version)
-    pub(crate) fn version_conflict(
-        node_id: u32,
-        term: u64,
-        version: u64,
-    ) -> Self {
-        Self {
-            id: node_id,
-            term,
-            version,
-            success: false,
-            error_code: ErrorCode::VersionConflict.into(),
-        }
-    }
-
-    /// Generate a failed response (Malformed change request)
-    #[allow(unused)]
-    pub(crate) fn invalid_change(
-        node_id: u32,
-        term: u64,
-        version: u64,
-    ) -> Self {
-        Self {
-            id: node_id,
-            term,
-            version,
-            success: false,
-            error_code: ErrorCode::InvalidChange.into(),
-        }
-    }
-
-    /// Generate a failed response (Server-side processing error)
-    pub(crate) fn internal_error(
-        node_id: u32,
-        term: u64,
-        version: u64,
-    ) -> Self {
-        Self {
-            id: node_id,
-            term,
-            version,
-            success: false,
-            error_code: ErrorCode::InternalError.into(),
-        }
-    }
-
-    #[allow(unused)]
-    pub(crate) fn is_higher_term(&self) -> bool {
-        self.error_code == <ErrorCode as Into<i32>>::into(ErrorCode::TermOutdated)
-    }
-}
-
-impl NodeStatus {
-    pub fn is_promotable(&self) -> bool {
-        matches!(self, NodeStatus::Syncing)
-    }
-
-    pub fn is_i32_promotable(value: i32) -> bool {
-        matches!(value, v if v == (NodeStatus::Syncing as i32))
+pub fn ensure_safe_join(
+    node_id: u32,
+    current_voters: usize,
+) -> Result<()> {
+    // Total voters including leader = current_voters + 1
+    let total_voters = current_voters + 1;
+
+    // Always allow if cluster will have even number of voters
+    if (total_voters + 1).is_multiple_of(2) {
+        Ok(())
+    } else {
+        // metrics::counter!("cluster.unsafe_join_attempts", 1);
+        metrics::counter!(
+            "cluster.unsafe_join_attempts",
+            &[("node_id", node_id.to_string())]
+        )
+        .increment(1);
+
+        warn!(
+            "Unsafe join attempt: current_voters={} (total_voters={})",
+            current_voters, total_voters
+        );
+        Err(
+            MembershipError::JoinClusterError("Cluster must maintain odd number of voters".into())
+                .into(),
+        )
     }
 }
diff --git a/src/network/grpc/backgroup_snapshot_transfer.rs b/d-engine-core/src/network/backgroup_snapshot_transfer.rs
similarity index 98%
rename from src/network/grpc/backgroup_snapshot_transfer.rs
rename to d-engine-core/src/network/backgroup_snapshot_transfer.rs
index d1ca9c0b..89d4fa80 100644
--- a/src/network/grpc/backgroup_snapshot_transfer.rs
+++ b/d-engine-core/src/network/backgroup_snapshot_transfer.rs
@@ -6,31 +6,31 @@ use std::pin::Pin;
 use std::sync::Arc;
 use std::time::Duration;
 
-use futures::stream::BoxStream;
 use futures::Stream;
 use futures::StreamExt;
+use futures::stream::BoxStream;
 use lru::LruCache;
 use tokio::sync::mpsc;
 use tokio::sync::mpsc::error::TrySendError;
-use tokio::time::sleep;
 use tokio::time::Instant;
+use tokio::time::sleep;
 use tokio_stream::wrappers::ReceiverStream;
+use tonic::Status;
 use tonic::codec::CompressionEncoding;
 use tonic::transport::Channel;
-use tonic::Status;
 use tracing::debug;
 use tracing::trace;
 use tracing::warn;
 
-use crate::proto::storage::snapshot_ack::ChunkStatus;
-use crate::proto::storage::snapshot_service_client::SnapshotServiceClient;
-use crate::proto::storage::SnapshotAck;
-use crate::proto::storage::SnapshotChunk;
 use crate::NetworkError;
 use crate::Result;
 use crate::SnapshotConfig;
 use crate::SnapshotError;
 use crate::TypeConfig;
+use d_engine_proto::server::storage::SnapshotAck;
+use d_engine_proto::server::storage::SnapshotChunk;
+use d_engine_proto::server::storage::snapshot_ack::ChunkStatus;
+use d_engine_proto::server::storage::snapshot_service_client::SnapshotServiceClient;
 
 pub(crate) struct BackgroundSnapshotTransfer<T> {
     _marker: PhantomData<T>,
diff --git a/src/network/grpc/backgroup_snapshot_transfer_test.rs b/d-engine-core/src/network/backgroup_snapshot_transfer_test.rs
similarity index 92%
rename from src/network/grpc/backgroup_snapshot_transfer_test.rs
rename to d-engine-core/src/network/backgroup_snapshot_transfer_test.rs
index daf57b6b..00b9aada 100644
--- a/src/network/grpc/backgroup_snapshot_transfer_test.rs
+++ b/d-engine-core/src/network/backgroup_snapshot_transfer_test.rs
@@ -1,24 +1,49 @@
 use std::time::Duration;
 
 use bytes::Bytes;
-use futures::stream;
 use futures::StreamExt;
+use futures::stream;
+use futures::stream::BoxStream;
 use tokio::sync::oneshot;
 use tokio::time::Instant;
 use tonic::Status;
 use tracing::debug;
 
 use super::*;
-use crate::proto::storage::SnapshotChunk;
-use crate::proto::storage::SnapshotResponse;
-use crate::test_utils::create_snapshot_stream;
-use crate::test_utils::MockNode;
-use crate::test_utils::MockTypeConfig;
 use crate::Error;
+use crate::MockTypeConfig;
 use crate::NetworkError;
 use crate::SnapshotConfig;
 use crate::SnapshotError;
 use crate::StorageError;
+use crate::create_test_chunk;
+use crate::create_test_snapshot_stream;
+use d_engine_proto::server::storage::SnapshotChunk;
+use d_engine_proto::server::storage::SnapshotResponse;
+
+/// Helper to create a valid snapshot stream
+fn create_snapshot_stream(
+    chunks: usize,
+    chunk_size: usize,
+) -> BoxStream<'static, Result<SnapshotChunk>> {
+    let chunks: Vec<SnapshotChunk> = (0..chunks)
+        .map(|seq| {
+            let data = vec![seq as u8; chunk_size];
+            create_test_chunk(
+                seq as u32,
+                &data,
+                1, // term
+                1, // leader_id
+                chunks as u32,
+            )
+        })
+        .collect();
+
+    let stream = create_test_snapshot_stream(chunks);
+    Box::pin(
+        stream.map(|item| item.map_err(|s| NetworkError::TonicStatusError(Box::new(s)).into())),
+    )
+}
 
 fn default_snapshot_config() -> SnapshotConfig {
     SnapshotConfig {
@@ -53,7 +78,7 @@ fn create_snapshot_chunk(
 #[cfg(test)]
 mod run_push_transfer_test {
     use super::*;
-    use crate::SystemError;
+    use crate::{MockNode, SystemError};
 
     #[tokio::test]
     async fn test_push_transfer_success() {
diff --git a/src/network/mod.rs b/d-engine-core/src/network/mod.rs
similarity index 89%
rename from src/network/mod.rs
rename to d-engine-core/src/network/mod.rs
index 879eeddb..372668c4 100644
--- a/src/network/mod.rs
+++ b/d-engine-core/src/network/mod.rs
@@ -5,52 +5,35 @@
 //! timeout policies for distributed system operations. All network operations
 //! are governed by timeout parameters defined in [`RaftConfig`] to ensure
 //! system responsiveness.
-pub mod grpc;
 
-mod connection_cache;
-mod health_checker;
-mod health_monitor;
+mod backgroup_snapshot_transfer;
 
-pub(crate) use connection_cache::*;
-pub(crate) use health_checker::*;
-pub(crate) use health_monitor::*;
-
-#[cfg(test)]
-mod connection_cache_test;
 #[cfg(test)]
-mod health_checker_test;
-#[cfg(test)]
-mod health_monitor_test;
+mod backgroup_snapshot_transfer_test;
+pub(crate) use backgroup_snapshot_transfer::*;
 
-// Trait definition of the current module
-// -----------------------------------------------------------------------------
-// Core model in Raft: Transport Definition
-//
-#[cfg(test)]
-mod network_test;
-
-#[cfg(test)]
+#[cfg(any(test, feature = "test-utils"))]
 use mockall::automock;
 use tonic::async_trait;
 
-use crate::proto::cluster::ClusterConfChangeRequest;
-use crate::proto::cluster::ClusterConfUpdateResponse;
-use crate::proto::election::VoteRequest;
-use crate::proto::election::VoteResponse;
-use crate::proto::replication::AppendEntriesRequest;
-use crate::proto::replication::AppendEntriesResponse;
-use crate::proto::storage::PurgeLogRequest;
-use crate::proto::storage::PurgeLogResponse;
-use crate::proto::storage::SnapshotChunk;
 use crate::BackoffPolicy;
 use crate::NetworkError;
 use crate::Result;
 use crate::RetryPolicies;
 use crate::TypeConfig;
+use d_engine_proto::server::cluster::ClusterConfChangeRequest;
+use d_engine_proto::server::cluster::ClusterConfUpdateResponse;
+use d_engine_proto::server::election::VoteRequest;
+use d_engine_proto::server::election::VoteResponse;
+use d_engine_proto::server::replication::AppendEntriesRequest;
+use d_engine_proto::server::replication::AppendEntriesResponse;
+use d_engine_proto::server::storage::PurgeLogRequest;
+use d_engine_proto::server::storage::PurgeLogResponse;
+use d_engine_proto::server::storage::SnapshotChunk;
 
 // Define a structured return value
 #[derive(Debug, Clone)]
-pub(crate) struct AppendResults {
+pub struct AppendResults {
     /// Whether a majority quorum is achieved (can be directly determined via
     /// peer_updates)
     pub commit_quorum_achieved: bool,
@@ -61,7 +44,7 @@ pub(crate) struct AppendResults {
 }
 
 #[derive(Debug, Clone, PartialEq)]
-pub(crate) struct PeerUpdate {
+pub struct PeerUpdate {
     pub match_index: Option<u64>,
     pub next_index: u64,
     /// if peer response success
@@ -107,7 +90,7 @@ pub struct ClusterUpdateResult {
     pub responses: Vec<Result<ClusterConfUpdateResponse>>,
 }
 
-#[cfg_attr(test, automock)]
+#[cfg_attr(any(test, feature = "test-utils"), automock)]
 #[async_trait]
 pub trait Transport<T>: Send + Sync + 'static
 where
@@ -257,10 +240,10 @@ where
     async fn join_cluster(
         &self,
         leader_id: u32,
-        request: crate::proto::cluster::JoinRequest,
+        request: d_engine_proto::server::cluster::JoinRequest,
         retry: BackoffPolicy,
         membership: std::sync::Arc<crate::alias::MOF<T>>,
-    ) -> Result<crate::proto::cluster::JoinResponse>;
+    ) -> Result<d_engine_proto::server::cluster::JoinResponse>;
 
     /// Discovers current cluster leader
     ///
@@ -276,10 +259,10 @@ where
     /// - `NetworkError::DiscoveryTimeout`: When no response received
     async fn discover_leader(
         &self,
-        request: crate::proto::cluster::LeaderDiscoveryRequest,
+        request: d_engine_proto::server::cluster::LeaderDiscoveryRequest,
         rpc_enable_compression: bool,
         membership: std::sync::Arc<crate::alias::MOF<T>>,
-    ) -> Result<Vec<crate::proto::cluster::LeaderDiscoveryResponse>>;
+    ) -> Result<Vec<d_engine_proto::server::cluster::LeaderDiscoveryResponse>>;
 
     /// Requests and streams a snapshot from the current leader.
     ///
@@ -298,7 +281,7 @@ where
     async fn request_snapshot_from_leader(
         &self,
         leader_id: u32,
-        ack_tx: tokio::sync::mpsc::Receiver<crate::proto::storage::SnapshotAck>,
+        ack_tx: tokio::sync::mpsc::Receiver<d_engine_proto::server::storage::SnapshotAck>,
         retry: &crate::InstallSnapshotBackoffPolicy,
         membership: std::sync::Arc<crate::alias::MOF<T>>,
     ) -> Result<Box<tonic::Streaming<SnapshotChunk>>>;
@@ -319,7 +302,7 @@ use tracing::warn;
 use crate::Error;
 
 /// As soon as task has return we should return from this function
-pub(crate) async fn grpc_task_with_timeout_and_exponential_backoff<F, T, U>(
+pub async fn grpc_task_with_timeout_and_exponential_backoff<F, T, U>(
     task_name: &'static str,
     mut task: F,
     policy: BackoffPolicy,
diff --git a/src/core/purge/default_executor.rs b/d-engine-core/src/purge/default_executor.rs
similarity index 91%
rename from src/core/purge/default_executor.rs
rename to d-engine-core/src/purge/default_executor.rs
index 4d45889a..f912aefa 100644
--- a/src/core/purge/default_executor.rs
+++ b/d-engine-core/src/purge/default_executor.rs
@@ -2,12 +2,12 @@ use std::sync::Arc;
 
 use tonic::async_trait;
 
-use crate::alias::ROF;
-use crate::proto::common::LogId;
 use crate::PurgeExecutor;
 use crate::RaftLog;
 use crate::Result;
 use crate::TypeConfig;
+use crate::alias::ROF;
+use d_engine_proto::common::LogId;
 
 /// Default implementation using the configured log storage
 pub struct DefaultPurgeExecutor<T: TypeConfig> {
@@ -33,7 +33,7 @@ impl<T: TypeConfig> PurgeExecutor for DefaultPurgeExecutor<T> {
 }
 
 impl<T: TypeConfig> DefaultPurgeExecutor<T> {
-    pub(crate) fn new(raft_log: Arc<ROF<T>>) -> Self {
+    pub fn new(raft_log: Arc<ROF<T>>) -> Self {
         DefaultPurgeExecutor {
             raft_log,
             pending_purge: None,
diff --git a/src/core/purge/default_executor_test.rs b/d-engine-core/src/purge/default_executor_test.rs
similarity index 98%
rename from src/core/purge/default_executor_test.rs
rename to d-engine-core/src/purge/default_executor_test.rs
index af8bb708..cba035eb 100644
--- a/src/core/purge/default_executor_test.rs
+++ b/d-engine-core/src/purge/default_executor_test.rs
@@ -3,9 +3,9 @@ use std::sync::Arc;
 use tracing_test::traced_test;
 
 use super::*;
-use crate::test_utils::MockTypeConfig;
 use crate::Error;
 use crate::MockRaftLog;
+use crate::MockTypeConfig;
 
 // Assuming RaftLog is defined and can be mocked with mockall
 // For example, if RaftLog is a trait, you can mock it as follows:
diff --git a/src/core/purge/mod.rs b/d-engine-core/src/purge/mod.rs
similarity index 89%
rename from src/core/purge/mod.rs
rename to d-engine-core/src/purge/mod.rs
index 62dbb409..f32aa535 100644
--- a/src/core/purge/mod.rs
+++ b/d-engine-core/src/purge/mod.rs
@@ -1,4 +1,4 @@
-#![doc = include_str!("../../docs/architecture/raft-log-persistence-architecture.md")]
+#![doc = include_str!("../../../d-engine-docs/src/docs/architecture/raft-log-persistence-architecture.md")]
 //! Log compaction and purge management.
 //!
 //! Defines the interface for customizing log purge behavior in Raft leaders and followers.
@@ -6,17 +6,17 @@
 //! maintaining Raft's safety guarantees.
 
 mod default_executor;
-pub(crate) use default_executor::*;
+pub use default_executor::*;
 
 #[cfg(test)]
 mod default_executor_test;
 
-#[cfg(test)]
+#[cfg(any(test, feature = "test-utils"))]
 use mockall::automock;
 use tonic::async_trait;
 
-use crate::proto::common::LogId;
 use crate::Result;
+use d_engine_proto::common::LogId;
 
 /// Defines the behavior for log entry compaction and physical deletion.
 ///
@@ -25,7 +25,7 @@ use crate::Result;
 /// 1. All entries up to `last_included.index` are preserved in snapshots
 /// 2. No concurrent modifications during purge execution
 /// 3. Atomic persistence of purge metadata
-#[cfg_attr(test, automock)]
+#[cfg_attr(any(test, feature = "test-utils"), automock)]
 #[async_trait]
 pub trait PurgeExecutor: Send + Sync + 'static {
     /// Physically removes log entries up to specified index (inclusive)
diff --git a/src/core/raft.rs b/d-engine-core/src/raft.rs
similarity index 76%
rename from src/core/raft.rs
rename to d-engine-core/src/raft.rs
index bc3fe41e..f68ddd52 100644
--- a/src/core/raft.rs
+++ b/d-engine-core/src/raft.rs
@@ -9,8 +9,6 @@ use tracing::info;
 use tracing::trace;
 use tracing::warn;
 
-#[cfg(test)]
-use super::raft_event_to_test_event;
 use super::NewCommitData;
 use super::RaftContext;
 use super::RaftCoreHandlers;
@@ -18,30 +16,32 @@ use super::RaftEvent;
 use super::RaftRole;
 use super::RaftStorageHandles;
 use super::RoleEvent;
-use crate::alias::MOF;
-use crate::alias::TROF;
-use crate::proto::common::EntryPayload;
+#[cfg(any(test, feature = "test-utils"))]
+use super::raft_event_to_test_event;
 use crate::Membership;
 use crate::NetworkError;
 use crate::RaftLog;
 use crate::RaftNodeConfig;
 use crate::Result;
 use crate::TypeConfig;
+use crate::alias::MOF;
+use crate::alias::TROF;
+use d_engine_proto::common::EntryPayload;
 
 pub struct Raft<T>
 where
     T: TypeConfig,
 {
-    pub(crate) node_id: u32,
-    pub(crate) role: RaftRole<T>,
-    pub(crate) ctx: RaftContext<T>,
+    pub node_id: u32,
+    pub role: RaftRole<T>,
+    pub ctx: RaftContext<T>,
 
     // Network & Storage events
-    pub(crate) event_tx: mpsc::Sender<RaftEvent>,
+    event_tx: mpsc::Sender<RaftEvent>,
     event_rx: mpsc::Receiver<RaftEvent>,
 
     // Timer
-    pub(crate) role_tx: mpsc::UnboundedSender<RoleEvent>,
+    role_tx: mpsc::UnboundedSender<RoleEvent>,
     role_rx: mpsc::UnboundedReceiver<RoleEvent>,
 
     // For business logic to apply logs into state machine
@@ -51,14 +51,14 @@ where
     shutdown_signal: watch::Receiver<()>,
 
     // For unit test
-    #[cfg(test)]
+    #[cfg(any(test, feature = "test-utils"))]
     test_role_transition_listener: Vec<mpsc::UnboundedSender<i32>>,
 
-    #[cfg(test)]
+    #[cfg(any(test, feature = "test-utils"))]
     test_raft_event_listener: Vec<mpsc::UnboundedSender<super::TestEvent>>,
 }
 
-pub(crate) struct SignalParams {
+pub struct SignalParams {
     pub(crate) role_tx: mpsc::UnboundedSender<RoleEvent>,
     pub(crate) role_rx: mpsc::UnboundedReceiver<RoleEvent>,
     pub(crate) event_tx: mpsc::Sender<RaftEvent>,
@@ -66,12 +66,34 @@ pub(crate) struct SignalParams {
     pub(crate) shutdown_signal: watch::Receiver<()>,
 }
 
+impl SignalParams {
+    /// Creates a new SignalParams with the provided channels.
+    ///
+    /// This is the only way to construct SignalParams from outside d-engine-core,
+    /// ensuring controlled initialization of the internal communication channels.
+    pub fn new(
+        role_tx: mpsc::UnboundedSender<RoleEvent>,
+        role_rx: mpsc::UnboundedReceiver<RoleEvent>,
+        event_tx: mpsc::Sender<RaftEvent>,
+        event_rx: mpsc::Receiver<RaftEvent>,
+        shutdown_signal: watch::Receiver<()>,
+    ) -> Self {
+        Self {
+            role_tx,
+            role_rx,
+            event_tx,
+            event_rx,
+            shutdown_signal,
+        }
+    }
+}
+
 impl<T> Raft<T>
 where
     T: TypeConfig,
 {
     #[allow(clippy::too_many_arguments)]
-    pub(crate) fn new(
+    pub fn new(
         node_id: u32,
         role: RaftRole<T>,
         storage: RaftStorageHandles<T>,
@@ -105,10 +127,10 @@ where
 
             shutdown_signal: signal_params.shutdown_signal,
 
-            #[cfg(test)]
+            #[cfg(any(test, feature = "test-utils"))]
             test_role_transition_listener: Vec::new(),
 
-            #[cfg(test)]
+            #[cfg(any(test, feature = "test-utils"))]
             test_raft_event_listener: Vec::new(),
         }
     }
@@ -209,14 +231,14 @@ where
                 Some(raft_event) = self.event_rx.recv() => {
                     trace!(%self.node_id, ?raft_event, "receive raft event");
 
-                    #[cfg(test)]
+                    #[cfg(any(test, feature = "test-utils"))]
                     let event = raft_event_to_test_event(&raft_event);
 
                     if let Err(e) = self.role.handle_raft_event(raft_event, &self.ctx, self.role_tx.clone()).await {
                         error!(%self.node_id, ?e, "handle_raft_event error");
                     }
 
-                    #[cfg(test)]
+                    #[cfg(any(test, feature = "test-utils"))]
                     self.notify_raft_event(event);
                 }
 
@@ -226,7 +248,7 @@ where
 
     /// `handle_role_event` will be responsbile to process role trasnsition and
     /// role state events.
-    pub(crate) async fn handle_role_event(
+    pub async fn handle_role_event(
         &mut self,
         role_event: RoleEvent,
     ) -> Result<()> {
@@ -237,7 +259,7 @@ where
                 debug!("BecomeFollower");
                 self.role = self.role.become_follower()?;
 
-                #[cfg(test)]
+                #[cfg(any(test, feature = "test-utils"))]
                 self.notify_role_transition();
 
                 //TODO: update membership
@@ -246,7 +268,7 @@ where
                 debug!("BecomeCandidate");
                 self.role = self.role.become_candidate()?;
 
-                #[cfg(test)]
+                #[cfg(any(test, feature = "test-utils"))]
                 self.notify_role_transition();
             }
             RoleEvent::BecomeLeader => {
@@ -272,7 +294,9 @@ where
                     .await
                     .unwrap_or(false)
                 {
-                    warn!("Verify leadership in new term failed. Now the node is going to step back to Follower...");
+                    warn!(
+                        "Verify leadership in new term failed. Now the node is going to step back to Follower..."
+                    );
                     self.role_tx.send(RoleEvent::BecomeFollower(None)).map_err(|e| {
                         let error_str = format!("{e:?}");
                         error!("Failed to send: {}", error_str);
@@ -280,14 +304,14 @@ where
                     })?;
                 }
 
-                #[cfg(test)]
+                #[cfg(any(test, feature = "test-utils"))]
                 self.notify_role_transition();
             }
             RoleEvent::BecomeLearner => {
                 debug!("BecomeLearner");
                 self.role = self.role.become_learner()?;
 
-                #[cfg(test)]
+                #[cfg(any(test, feature = "test-utils"))]
                 self.notify_role_transition();
             }
             RoleEvent::NotifyNewCommitIndex(new_commit_data) => {
@@ -311,14 +335,14 @@ where
         Ok(())
     }
 
-    pub(crate) fn register_new_commit_listener(
+    pub fn register_new_commit_listener(
         &mut self,
         tx: mpsc::UnboundedSender<NewCommitData>,
     ) {
         self.new_commit_listener.push(tx);
     }
 
-    pub(crate) fn notify_new_commit(
+    pub fn notify_new_commit(
         &self,
         new_commit_data: NewCommitData,
     ) {
@@ -331,32 +355,32 @@ where
         }
     }
 
-    #[cfg(test)]
-    pub(crate) fn register_role_transition_listener(
+    #[cfg(any(test, feature = "test-utils"))]
+    pub fn register_role_transition_listener(
         &mut self,
         tx: mpsc::UnboundedSender<i32>,
     ) {
         self.test_role_transition_listener.push(tx);
     }
 
-    #[cfg(test)]
-    pub(crate) fn notify_role_transition(&self) {
+    #[cfg(any(test, feature = "test-utils"))]
+    pub fn notify_role_transition(&self) {
         let new_role_i32 = self.role.as_i32();
         for tx in &self.test_role_transition_listener {
             tx.send(new_role_i32).expect("should succeed");
         }
     }
 
-    #[cfg(test)]
-    pub(crate) fn register_raft_event_listener(
+    #[cfg(any(test, feature = "test-utils"))]
+    pub fn register_raft_event_listener(
         &mut self,
         tx: mpsc::UnboundedSender<super::TestEvent>,
     ) {
         self.test_raft_event_listener.push(tx);
     }
 
-    #[cfg(test)]
-    pub(crate) fn notify_raft_event(
+    #[cfg(any(test, feature = "test-utils"))]
+    pub fn notify_raft_event(
         &self,
         event: super::TestEvent,
     ) {
@@ -367,13 +391,37 @@ where
         }
     }
 
-    #[cfg(test)]
-    pub(crate) fn set_role(
+    #[cfg(any(test, feature = "test-utils"))]
+    pub fn set_role(
         &mut self,
         role: RaftRole<T>,
     ) {
         self.role = role
     }
+
+    /// Returns a cloned event sender for external use.
+    ///
+    /// This provides controlled access to send validated RaftEvents to the Raft core.
+    /// Events sent through this sender are still processed through the normal validation
+    /// pipeline in the main event loop.
+    ///
+    /// # Security Note
+    /// While this provides access to the event channel, all events are still validated
+    /// by the Raft state machine before being applied. The event handler in `handle_raft_event`
+    /// performs necessary checks based on current term, role, and state.
+    pub fn event_sender(&self) -> mpsc::Sender<RaftEvent> {
+        self.event_tx.clone()
+    }
+
+    /// Returns a cloned role event sender for internal use.
+    ///
+    /// # Warning
+    /// This is primarily for internal components that need to trigger role transitions.
+    /// External callers should not use this unless they understand the Raft protocol deeply.
+    #[doc(hidden)]
+    pub fn role_event_sender(&self) -> mpsc::UnboundedSender<RoleEvent> {
+        self.role_tx.clone()
+    }
 }
 
 impl<T> Drop for Raft<T>
diff --git a/src/core/raft_context.rs b/d-engine-core/src/raft_context.rs
similarity index 73%
rename from src/core/raft_context.rs
rename to d-engine-core/src/raft_context.rs
index 45abf5e3..c4ca618e 100644
--- a/src/core/raft_context.rs
+++ b/d-engine-core/src/raft_context.rs
@@ -1,6 +1,8 @@
 use std::fmt::Debug;
 use std::sync::Arc;
 
+use crate::RaftNodeConfig;
+use crate::TypeConfig;
 use crate::alias::EOF;
 use crate::alias::MOF;
 use crate::alias::PE;
@@ -9,43 +11,41 @@ use crate::alias::ROF;
 use crate::alias::SMHOF;
 use crate::alias::SMOF;
 use crate::alias::TROF;
-use crate::RaftNodeConfig;
-use crate::TypeConfig;
 
-pub(crate) struct RaftStorageHandles<T: TypeConfig> {
-    pub(crate) raft_log: Arc<ROF<T>>,
-    pub(crate) state_machine: Arc<SMOF<T>>,
+pub struct RaftStorageHandles<T: TypeConfig> {
+    pub raft_log: Arc<ROF<T>>,
+    pub state_machine: Arc<SMOF<T>>,
 }
 
-pub(crate) struct RaftCoreHandlers<T: TypeConfig> {
-    pub(crate) election_handler: EOF<T>,
-    pub(crate) replication_handler: REPOF<T>,
-    pub(crate) state_machine_handler: Arc<SMHOF<T>>,
+pub struct RaftCoreHandlers<T: TypeConfig> {
+    pub election_handler: EOF<T>,
+    pub replication_handler: REPOF<T>,
+    pub state_machine_handler: Arc<SMHOF<T>>,
 
     // Raft Log Purge Executor
-    pub(crate) purge_executor: Arc<PE<T>>,
+    pub purge_executor: Arc<PE<T>>,
 }
 
-pub(crate) struct RaftContext<T>
+pub struct RaftContext<T>
 where
     T: TypeConfig,
 {
-    pub(crate) node_id: u32,
+    pub node_id: u32,
 
     // Storages
-    pub(crate) storage: RaftStorageHandles<T>,
+    pub storage: RaftStorageHandles<T>,
 
     // Network
-    pub(crate) transport: Arc<TROF<T>>,
+    pub transport: Arc<TROF<T>>,
 
     // Cluster Membership
-    pub(crate) membership: Arc<MOF<T>>,
+    pub membership: Arc<MOF<T>>,
 
     // Handlers
-    pub(crate) handlers: RaftCoreHandlers<T>,
+    pub handlers: RaftCoreHandlers<T>,
 
     // RaftNodeConfig
-    pub(crate) node_config: Arc<RaftNodeConfig>,
+    pub node_config: Arc<RaftNodeConfig>,
 }
 
 impl<T> RaftContext<T>
@@ -91,7 +91,7 @@ where
         &self.membership
     }
 
-    #[cfg(test)]
+    #[cfg(any(test, feature = "test-utils"))]
     pub fn set_membership(
         &mut self,
         membership: Arc<MOF<T>>,
@@ -99,7 +99,7 @@ where
         self.membership = membership;
     }
 
-    #[cfg(test)]
+    #[cfg(any(test, feature = "test-utils"))]
     pub fn set_transport(
         &mut self,
         transport: Arc<TROF<T>>,
diff --git a/src/core/raft_oneshot_test.rs b/d-engine-core/src/raft_oneshot_test.rs
similarity index 100%
rename from src/core/raft_oneshot_test.rs
rename to d-engine-core/src/raft_oneshot_test.rs
diff --git a/src/core/raft_role/candidate_state.rs b/d-engine-core/src/raft_role/candidate_state.rs
similarity index 95%
rename from src/core/raft_role/candidate_state.rs
rename to d-engine-core/src/raft_role/candidate_state.rs
index fb804888..5a30f836 100644
--- a/src/core/raft_role/candidate_state.rs
+++ b/d-engine-core/src/raft_role/candidate_state.rs
@@ -4,28 +4,21 @@ use std::sync::Arc;
 
 use tokio::sync::mpsc;
 use tokio::time::Instant;
-use tonic::async_trait;
 use tonic::Status;
+use tonic::async_trait;
 use tracing::debug;
 use tracing::error;
 use tracing::info;
 use tracing::trace;
 use tracing::warn;
 
-use super::can_serve_read_locally;
-use super::follower_state::FollowerState;
-use super::role_state::RaftRoleState;
 use super::RaftRole;
 use super::Result;
 use super::SharedState;
 use super::StateSnapshot;
-use super::CANDIDATE;
-use crate::proto::client::ClientResponse;
-use crate::proto::cluster::ClusterConfUpdateResponse;
-use crate::proto::common::LogId;
-use crate::proto::election::VoteResponse;
-use crate::proto::election::VotedFor;
-use crate::proto::error::ErrorCode;
+use super::can_serve_read_locally;
+use super::follower_state::FollowerState;
+use super::role_state::RaftRoleState;
 use crate::ConsensusError;
 use crate::ElectionCore;
 use crate::ElectionError;
@@ -42,6 +35,13 @@ use crate::RoleEvent;
 use crate::StateMachineHandler;
 use crate::StateTransitionError;
 use crate::TypeConfig;
+use d_engine_proto::client::ClientResponse;
+use d_engine_proto::common::LogId;
+use d_engine_proto::common::NodeRole::Candidate;
+use d_engine_proto::error::ErrorCode;
+use d_engine_proto::server::cluster::ClusterConfUpdateResponse;
+use d_engine_proto::server::election::VoteResponse;
+use d_engine_proto::server::election::VotedFor;
 
 /// Candidate node's volatile state during leader election.
 ///
@@ -62,7 +62,7 @@ pub struct CandidateState<T: TypeConfig> {
     /// Note:
     /// Even though candidates don’t purge logs, they must keep last_purged_index from the
     /// follower. Otherwise, the system may lose purge info and get into an inconsistent state.
-    pub(super) last_purged_index: Option<LogId>,
+    pub last_purged_index: Option<LogId>,
 
     // -- Election Timing --
     /// Election timeout manager
@@ -262,7 +262,9 @@ impl<T: TypeConfig> RaftRoleState for CandidateState<T> {
                     // Step down as Follower
                     self.send_become_follower_event(&role_tx)?;
 
-                    info!("Candiate will not process ReceiveVoteRequest, it should let Follower do it.");
+                    info!(
+                        "Candiate will not process ReceiveVoteRequest, it should let Follower do it."
+                    );
                     self.send_replay_raft_event(
                         &role_tx,
                         RaftEvent::ReceiveVoteRequest(vote_request, sender),
@@ -373,7 +375,9 @@ impl<T: TypeConfig> RaftRoleState for CandidateState<T> {
                     // Step down as Follower
                     self.send_become_follower_event(&role_tx)?;
 
-                    info!("Candiate will not process AppendEntries request, it should let Follower do it.");
+                    info!(
+                        "Candiate will not process AppendEntries request, it should let Follower do it."
+                    );
                     self.send_replay_raft_event(
                         &role_tx,
                         RaftEvent::AppendEntries(append_entries_request, sender),
@@ -410,8 +414,8 @@ impl<T: TypeConfig> RaftRoleState for CandidateState<T> {
                     None => {
                         // Policy requires leader access - reject
                         let error = tonic::Status::permission_denied(
-                                    "Read consistency policy requires leader access. Current node is candidate."
-                                );
+                            "Read consistency policy requires leader access. Current node is candidate.",
+                        );
                         sender.send(Err(error)).map_err(|e| {
                             error!("Failed to send policy rejection: {:?}", e);
                             NetworkError::SingalSendFailed(format!("{e:?}"))
@@ -460,7 +464,7 @@ impl<T: TypeConfig> RaftRoleState for CandidateState<T> {
                         ctx.node_id
                     ),
                 }
-                .into())
+                .into());
             }
 
             RaftEvent::SnapshotCreated(_result) => {
@@ -472,7 +476,7 @@ impl<T: TypeConfig> RaftRoleState for CandidateState<T> {
                         ctx.node_id
                     ),
                 }
-                .into())
+                .into());
             }
 
             RaftEvent::LogPurgeCompleted(_purged_id) => {
@@ -484,7 +488,7 @@ impl<T: TypeConfig> RaftRoleState for CandidateState<T> {
                         ctx.node_id
                     ),
                 }
-                .into())
+                .into());
             }
 
             RaftEvent::JoinCluster(_join_request, sender) => {
@@ -602,11 +606,11 @@ impl<T: TypeConfig> CandidateState<T> {
             current_term: self.current_term(),
             voted_for: None,
             commit_index: self.commit_index(),
-            role: CANDIDATE,
+            role: Candidate.into(),
         }
     }
 
-    pub(super) fn send_become_follower_event(
+    pub fn send_become_follower_event(
         &self,
         role_tx: &mpsc::UnboundedSender<RoleEvent>,
     ) -> Result<()> {
@@ -617,7 +621,7 @@ impl<T: TypeConfig> CandidateState<T> {
         })
     }
 
-    pub(super) fn send_replay_raft_event(
+    pub fn send_replay_raft_event(
         &self,
         role_tx: &mpsc::UnboundedSender<RoleEvent>,
         raft_event: RaftEvent,
@@ -630,7 +634,7 @@ impl<T: TypeConfig> CandidateState<T> {
         })
     }
 
-    #[cfg(test)]
+    #[cfg(any(test, feature = "test-utils"))]
     pub fn new(
         node_id: u32,
         node_config: Arc<RaftNodeConfig>,
diff --git a/src/core/raft_role/follower_state.rs b/d-engine-core/src/raft_role/follower_state.rs
similarity index 97%
rename from src/core/raft_role/follower_state.rs
rename to d-engine-core/src/raft_role/follower_state.rs
index f5a78b08..3d2a5f66 100644
--- a/src/core/raft_role/follower_state.rs
+++ b/d-engine-core/src/raft_role/follower_state.rs
@@ -4,8 +4,8 @@ use std::sync::Arc;
 
 use tokio::sync::mpsc;
 use tokio::time::Instant;
-use tonic::async_trait;
 use tonic::Status;
+use tonic::async_trait;
 use tracing::debug;
 use tracing::error;
 use tracing::info;
@@ -13,26 +13,15 @@ use tracing::instrument;
 use tracing::trace;
 use tracing::warn;
 
+use super::HardState;
+use super::RaftRole;
+use super::SharedState;
+use super::StateSnapshot;
 use super::can_serve_read_locally;
 use super::candidate_state::CandidateState;
 use super::leader_state::LeaderState;
 use super::learner_state::LearnerState;
 use super::role_state::RaftRoleState;
-use super::HardState;
-use super::RaftRole;
-use super::SharedState;
-use super::StateSnapshot;
-use super::FOLLOWER;
-use crate::proto::client::ClientResponse;
-use crate::proto::cluster::ClusterConfUpdateResponse;
-use crate::proto::common::LogId;
-use crate::proto::election::VoteResponse;
-use crate::proto::error::ErrorCode;
-use crate::proto::storage::snapshot_ack::ChunkStatus;
-use crate::proto::storage::PurgeLogResponse;
-use crate::proto::storage::SnapshotAck;
-use crate::proto::storage::SnapshotResponse;
-use crate::utils::cluster::error;
 use crate::ConsensusError;
 use crate::ElectionCore;
 use crate::ElectionTimer;
@@ -48,6 +37,17 @@ use crate::RoleEvent;
 use crate::StateMachineHandler;
 use crate::StateTransitionError;
 use crate::TypeConfig;
+use crate::utils::cluster::error;
+use d_engine_proto::client::ClientResponse;
+use d_engine_proto::common::LogId;
+use d_engine_proto::common::NodeRole::Follower;
+use d_engine_proto::error::ErrorCode;
+use d_engine_proto::server::cluster::ClusterConfUpdateResponse;
+use d_engine_proto::server::election::VoteResponse;
+use d_engine_proto::server::storage::PurgeLogResponse;
+use d_engine_proto::server::storage::SnapshotAck;
+use d_engine_proto::server::storage::SnapshotResponse;
+use d_engine_proto::server::storage::snapshot_ack::ChunkStatus;
 
 /// Follower node's state in Raft consensus.
 ///
@@ -63,7 +63,7 @@ pub struct FollowerState<T: TypeConfig> {
     // -- Log Compaction & Purge --
     /// === Persistent State ===
     /// Last physically purged log index (inclusive)
-    pub(super) last_purged_index: Option<LogId>,
+    pub last_purged_index: Option<LogId>,
 
     // -- Cluster Configuration --
     /// Node configuration (shared immutable reference)
@@ -360,8 +360,8 @@ impl<T: TypeConfig> RaftRoleState for FollowerState<T> {
                     None => {
                         // Policy requires leader access - reject
                         let error = tonic::Status::permission_denied(
-                                    "Read consistency policy requires leader access. Current node is follower."
-                                );
+                            "Read consistency policy requires leader access. Current node is follower.",
+                        );
                         sender.send(Err(error)).map_err(|e| {
                             error!("Failed to send policy rejection: {:?}", e);
                             NetworkError::SingalSendFailed(format!("{e:?}"))
@@ -497,7 +497,7 @@ impl<T: TypeConfig> RaftRoleState for FollowerState<T> {
                         ctx.node_id
                     ),
                 }
-                .into())
+                .into());
             }
 
             RaftEvent::CreateSnapshotEvent => {
@@ -509,7 +509,7 @@ impl<T: TypeConfig> RaftRoleState for FollowerState<T> {
                         ctx.node_id
                     ),
                 }
-                .into())
+                .into());
             }
 
             RaftEvent::SnapshotCreated(_result) => {
@@ -521,7 +521,7 @@ impl<T: TypeConfig> RaftRoleState for FollowerState<T> {
                         ctx.node_id
                     ),
                 }
-                .into())
+                .into());
             }
 
             RaftEvent::JoinCluster(_join_request, sender) => {
@@ -634,7 +634,7 @@ impl<T: TypeConfig> FollowerState<T> {
     #[tracing::instrument]
     pub fn state_snapshot(&self) -> StateSnapshot {
         StateSnapshot {
-            role: FOLLOWER,
+            role: Follower.into(),
             current_term: self.current_term(),
             voted_for: None,
             commit_index: self.commit_index(),
@@ -665,7 +665,7 @@ impl<T: TypeConfig> FollowerState<T> {
     /// - Critical for follower's log matching property during reelections
     /// - Prevents "phantom entries" when combined with §5.4.2 election restriction
     #[instrument(skip(self))]
-    pub(super) fn can_purge_logs(
+    pub fn can_purge_logs(
         &self,
         last_purge_index: Option<LogId>,
         last_included_in_request: LogId,
diff --git a/src/core/raft_role/leader_state.rs b/d-engine-core/src/raft_role/leader_state.rs
similarity index 96%
rename from src/core/raft_role/leader_state.rs
rename to d-engine-core/src/raft_role/leader_state.rs
index 1251db53..c3360bd6 100644
--- a/src/core/raft_role/leader_state.rs
+++ b/d-engine-core/src/raft_role/leader_state.rs
@@ -2,20 +2,20 @@ use std::collections::HashMap;
 use std::collections::VecDeque;
 use std::fmt::Debug;
 use std::marker::PhantomData;
+use std::sync::Arc;
 use std::sync::atomic::AtomicBool;
 use std::sync::atomic::AtomicU64;
 use std::sync::atomic::Ordering;
-use std::sync::Arc;
 use std::time::Duration;
 
 use nanoid::nanoid;
 use tokio::sync::mpsc;
 use tokio::sync::oneshot;
+use tokio::time::Instant;
 use tokio::time::sleep;
 use tokio::time::timeout;
-use tokio::time::Instant;
-use tonic::async_trait;
 use tonic::Status;
+use tonic::async_trait;
 use tracing::debug;
 use tracing::error;
 use tracing::info;
@@ -23,45 +23,14 @@ use tracing::instrument;
 use tracing::trace;
 use tracing::warn;
 
-use super::candidate_state::CandidateState;
-use super::role_state::RaftRoleState;
 use super::LeaderStateSnapshot;
 use super::RaftRole;
 use super::SharedState;
 use super::StateSnapshot;
-use super::LEADER;
-use crate::alias::MOF;
-use crate::alias::ROF;
-use crate::alias::SMHOF;
-use crate::client_command_to_entry_payloads;
-use crate::cluster::is_majority;
-use crate::ensure_safe_join;
-use crate::grpc::BackgroundSnapshotTransfer;
-use crate::proto::client::ClientResponse;
-use crate::proto::client::ReadConsistencyPolicy as ClientReadConsistencyPolicy;
-use crate::proto::cluster::ClusterConfUpdateResponse;
-use crate::proto::cluster::JoinRequest;
-use crate::proto::cluster::JoinResponse;
-use crate::proto::cluster::LeaderDiscoveryResponse;
-use crate::proto::common::membership_change::Change;
-use crate::proto::common::AddNode;
-use crate::proto::common::BatchPromote;
-use crate::proto::common::BatchRemove;
-use crate::proto::common::EntryPayload;
-use crate::proto::common::LogId;
-use crate::proto::common::NodeStatus;
-use crate::proto::election::VoteResponse;
-use crate::proto::election::VotedFor;
-use crate::proto::error::ErrorCode;
-use crate::proto::replication::AppendEntriesResponse;
-use crate::proto::storage::PurgeLogRequest;
-use crate::proto::storage::PurgeLogResponse;
-use crate::proto::storage::SnapshotChunk;
-use crate::proto::storage::SnapshotMetadata;
-use crate::scoped_timer::ScopedTimer;
-use crate::stream::create_production_snapshot_stream;
-use crate::utils::cluster::error;
+use super::candidate_state::CandidateState;
+use super::role_state::RaftRoleState;
 use crate::AppendResults;
+use crate::BackgroundSnapshotTransfer;
 use crate::BatchBuffer;
 use crate::ConnectionType;
 use crate::ConsensusError;
@@ -93,16 +62,47 @@ use crate::StateMachineHandler;
 use crate::StateTransitionError;
 use crate::Transport;
 use crate::TypeConfig;
+use crate::alias::MOF;
+use crate::alias::ROF;
+use crate::alias::SMHOF;
+use crate::client_command_to_entry_payloads;
+use crate::cluster::is_majority;
+use crate::ensure_safe_join;
+use crate::scoped_timer::ScopedTimer;
+use crate::stream::create_production_snapshot_stream;
+use crate::utils::cluster::error;
+use d_engine_proto::client::ClientResponse;
+use d_engine_proto::client::ReadConsistencyPolicy as ClientReadConsistencyPolicy;
+use d_engine_proto::common::AddNode;
+use d_engine_proto::common::BatchPromote;
+use d_engine_proto::common::BatchRemove;
+use d_engine_proto::common::EntryPayload;
+use d_engine_proto::common::LogId;
+use d_engine_proto::common::NodeRole::Leader;
+use d_engine_proto::common::NodeStatus;
+use d_engine_proto::common::membership_change::Change;
+use d_engine_proto::error::ErrorCode;
+use d_engine_proto::server::cluster::ClusterConfUpdateResponse;
+use d_engine_proto::server::cluster::JoinRequest;
+use d_engine_proto::server::cluster::JoinResponse;
+use d_engine_proto::server::cluster::LeaderDiscoveryResponse;
+use d_engine_proto::server::election::VoteResponse;
+use d_engine_proto::server::election::VotedFor;
+use d_engine_proto::server::replication::AppendEntriesResponse;
+use d_engine_proto::server::storage::PurgeLogRequest;
+use d_engine_proto::server::storage::PurgeLogResponse;
+use d_engine_proto::server::storage::SnapshotChunk;
+use d_engine_proto::server::storage::SnapshotMetadata;
 
 // Supporting data structures
 #[derive(Debug, Clone)]
-pub(crate) struct PendingPromotion {
-    pub(super) node_id: u32,
-    pub(super) ready_since: Instant,
+pub struct PendingPromotion {
+    pub node_id: u32,
+    pub ready_since: Instant,
 }
 
 impl PendingPromotion {
-    pub(crate) fn new(
+    pub fn new(
         node_id: u32,
         ready_since: Instant,
     ) -> Self {
@@ -129,7 +129,7 @@ pub struct LeaderState<T: TypeConfig> {
     /// For each server (node_id), index of the next log entry to send to that server
     ///
     /// Raft Paper: §5.3 Figure 2 (nextIndex)
-    pub(super) next_index: HashMap<u32, u64>,
+    pub next_index: HashMap<u32, u64>,
 
     /// === Volatile State ===
     /// For each server (node_id), index of highest log entry known to be replicated
@@ -150,7 +150,7 @@ pub struct LeaderState<T: TypeConfig> {
     ///
     /// The actual log purge is performed by a background task, which may be delayed
     /// due to resource constraints or retry mechanisms.
-    pub(super) scheduled_purge_upto: Option<LogId>,
+    pub scheduled_purge_upto: Option<LogId>,
 
     /// === Persistent State (MUST be on disk) ===
     /// The last log position that has been **physically removed** from stable storage.
@@ -162,17 +162,17 @@ pub struct LeaderState<T: TypeConfig> {
     /// Raft safety invariant:
     /// Any log entry with index ≤ `last_purged_index` is guaranteed to be
     /// reflected in the latest snapshot.
-    pub(super) last_purged_index: Option<LogId>,
+    pub last_purged_index: Option<LogId>,
 
     /// === Volatile State ===
     /// Peer purge progress tracking for flow control
     ///
     /// Key: Peer node ID
     /// Value: Last confirmed purge index from peer
-    pub(super) peer_purge_progress: HashMap<u32, u64>,
+    pub peer_purge_progress: HashMap<u32, u64>,
 
     /// Record if there is on-going snapshot creation activity
-    pub(super) snapshot_in_progress: AtomicBool,
+    pub snapshot_in_progress: AtomicBool,
 
     // -- Request Processing --
     /// Batched proposal buffer for client requests
@@ -216,10 +216,10 @@ pub struct LeaderState<T: TypeConfig> {
     ///
     /// Rationale: Avoiding frequent full scans improves batching efficiency and reduces CPU spikes
     /// in high-load environments (particularly crucial for RocketMQ-on-DLedger workflows).
-    pub(super) next_membership_maintenance_check: Instant,
+    pub next_membership_maintenance_check: Instant,
 
     /// Queue of learners that have caught up and are pending promotion to voter.
-    pub(super) pending_promotions: VecDeque<PendingPromotion>,
+    pub pending_promotions: VecDeque<PendingPromotion>,
 
     /// Lease timestamp for LeaseRead policy
     /// Tracks when leadership was last confirmed with quorum
@@ -739,7 +739,9 @@ impl<T: TypeConfig> RaftRoleState for LeaderState<T> {
                     //TODO: if there is a bug?  self.update_current_term(vote_request.term);
                     self.send_become_follower_event(Some(cluste_conf_change_request.id), &role_tx)?;
 
-                    info!("Leader will not process append_entries_request, it should let Follower do it.");
+                    info!(
+                        "Leader will not process append_entries_request, it should let Follower do it."
+                    );
                     send_replay_raft_event(
                         &role_tx,
                         RaftEvent::ClusterConfUpdate(cluste_conf_change_request, sender),
@@ -774,7 +776,9 @@ impl<T: TypeConfig> RaftRoleState for LeaderState<T> {
                         &role_tx,
                     )?;
 
-                    info!("Leader will not process append_entries_request, it should let Follower do it.");
+                    info!(
+                        "Leader will not process append_entries_request, it should let Follower do it."
+                    );
                     send_replay_raft_event(
                         &role_tx,
                         RaftEvent::AppendEntries(append_entries_request, sender),
@@ -864,7 +868,9 @@ impl<T: TypeConfig> RaftRoleState for LeaderState<T> {
                                 &ctx.handlers.state_machine_handler,
                                 last_applied_index,
                             ) {
-                                warn!("ensure_state_machine_upto_commit_index failed for linear read request");
+                                warn!(
+                                    "ensure_state_machine_upto_commit_index failed for linear read request"
+                                );
                                 Err(tonic::Status::failed_precondition(format!(
                                     "ensure_state_machine_upto_commit_index failed: {e:?}"
                                 )))
@@ -1196,7 +1202,7 @@ impl<T: TypeConfig> LeaderState<T> {
             current_term: self.current_term(),
             voted_for: None,
             commit_index: self.commit_index(),
-            role: LEADER,
+            role: Leader.into(),
         }
     }
 
@@ -1213,7 +1219,7 @@ impl<T: TypeConfig> LeaderState<T> {
     /// # Params
     /// - `execute_now`: should this propose been executed immediatelly. e.g.
     ///   enforce_quorum_consensus expected to be executed immediatelly
-    pub(crate) async fn process_raft_request(
+    pub async fn process_raft_request(
         &mut self,
         raft_request_with_signal: RaftRequestWithSignal,
         ctx: &RaftContext<T>,
@@ -1277,7 +1283,7 @@ impl<T: TypeConfig> LeaderState<T> {
     ///    - Client response: `ProposeFailed`
     ///    - State update: none
     ///    - Return: original error
-    pub(super) async fn process_batch(
+    pub async fn process_batch(
         &mut self,
         batch: VecDeque<RaftRequestWithSignal>,
         role_tx: &mpsc::UnboundedSender<RoleEvent>,
@@ -1333,7 +1339,7 @@ impl<T: TypeConfig> LeaderState<T> {
                         new_commit_index
                     );
                     self.update_commit_index_with_signal(
-                        LEADER,
+                        Leader.into(),
                         self.current_term(),
                         new_commit_index,
                         role_tx,
@@ -1422,8 +1428,7 @@ impl<T: TypeConfig> LeaderState<T> {
             }
             trace!(
                 "Updated next index for peer {}-{}",
-                peer_id,
-                update.next_index
+                peer_id, update.next_index
             );
             if let Some(match_index) = update.match_index {
                 if let Err(e) = self.update_match_index(*peer_id, match_index) {
@@ -1520,7 +1525,7 @@ impl<T: TypeConfig> LeaderState<T> {
     }
 
     #[allow(dead_code)]
-    pub(super) async fn batch_promote_learners(
+    pub async fn batch_promote_learners(
         &mut self,
         ready_learners_ids: Vec<u32>,
         ctx: &RaftContext<T>,
@@ -1632,7 +1637,7 @@ impl<T: TypeConfig> LeaderState<T> {
         (false, current_commit_index)
     }
 
-    pub(crate) fn ensure_state_machine_upto_commit_index(
+    pub fn ensure_state_machine_upto_commit_index(
         &self,
         state_machine_handler: &Arc<SMHOF<T>>,
         last_applied: u64,
@@ -1744,7 +1749,7 @@ impl<T: TypeConfig> LeaderState<T> {
     /// - Design differs from followers by requiring full cluster confirmation (Raft extension for
     ///   enhanced durability)
     #[instrument(skip(self))]
-    pub(super) fn can_purge_logs(
+    pub fn can_purge_logs(
         &self,
         last_purge_index: Option<LogId>,
         last_included_in_snapshot: LogId,
@@ -1761,7 +1766,7 @@ impl<T: TypeConfig> LeaderState<T> {
             && self.peer_purge_progress.values().all(|&v| v >= last_included_in_snapshot.index)
     }
 
-    pub(super) async fn handle_join_cluster(
+    pub async fn handle_join_cluster(
         &mut self,
         join_request: JoinRequest,
         sender: MaybeCloneOneshotSender<std::result::Result<JoinResponse, Status>>,
@@ -1881,8 +1886,8 @@ impl<T: TypeConfig> LeaderState<T> {
         Err(error)
     }
 
-    #[cfg(test)]
-    pub(crate) fn new(
+    #[cfg(any(test, feature = "test-utils"))]
+    pub fn new(
         node_id: u32,
         node_config: Arc<RaftNodeConfig>,
     ) -> Self {
@@ -1921,7 +1926,7 @@ impl<T: TypeConfig> LeaderState<T> {
         }
     }
 
-    pub(super) async fn trigger_background_snapshot(
+    pub async fn trigger_background_snapshot(
         node_id: u32,
         metadata: SnapshotMetadata,
         state_machine_handler: Arc<SMHOF<T>>,
@@ -1968,7 +1973,7 @@ impl<T: TypeConfig> LeaderState<T> {
     }
 
     /// Processes all pending promotions while respecting the cluster's odd-node constraint
-    pub(super) async fn process_pending_promotions(
+    pub async fn process_pending_promotions(
         &mut self,
         ctx: &RaftContext<T>,
         role_tx: &mpsc::UnboundedSender<RoleEvent>,
@@ -2113,7 +2118,7 @@ impl<T: TypeConfig> LeaderState<T> {
     /// Periodic check triggered every ~30s in the worst-case scenario
     /// using priority-based lazy scheduling. Actual average frequency
     /// is inversely proportional to system load.
-    pub(super) async fn conditionally_purge_stale_learners(
+    pub async fn conditionally_purge_stale_learners(
         &mut self,
         ctx: &RaftContext<T>,
     ) -> Result<()> {
@@ -2220,7 +2225,7 @@ impl<T: TypeConfig> LeaderState<T> {
         Ok(())
     }
 
-    pub(super) fn reset_next_membership_maintenance_check(
+    pub fn reset_next_membership_maintenance_check(
         &mut self,
         membership_maintenance_interval: Duration,
     ) {
@@ -2228,7 +2233,7 @@ impl<T: TypeConfig> LeaderState<T> {
     }
 
     /// FINRA Rule 4370-approved remediation
-    pub(super) async fn handle_stale_learner(
+    pub async fn handle_stale_learner(
         &mut self,
         node_id: u32,
         ctx: &RaftContext<T>,
@@ -2251,7 +2256,7 @@ impl<T: TypeConfig> LeaderState<T> {
     }
 
     /// Check if current lease is still valid for LeaseRead policy
-    pub(super) fn is_lease_valid(
+    pub fn is_lease_valid(
         &self,
         ctx: &RaftContext<T>,
     ) -> bool {
@@ -2281,12 +2286,12 @@ impl<T: TypeConfig> LeaderState<T> {
         self.lease_timestamp.store(now, std::sync::atomic::Ordering::Release);
     }
 
-    #[cfg(test)]
+    #[cfg(any(test, feature = "test-utils"))]
     pub fn test_update_lease_timestamp(&self) {
         self.update_lease_timestamp();
     }
 
-    #[cfg(test)]
+    #[cfg(any(test, feature = "test-utils"))]
     pub fn test_set_lease_timestamp(
         &self,
         timestamp: u64,
@@ -2356,7 +2361,7 @@ impl<T: TypeConfig> Debug for LeaderState<T> {
 /// - `available`: number of ready learners pending promotion
 ///
 /// Returns the maximum number of nodes to promote (0 if no safe promotion exists)
-pub(super) fn calculate_safe_batch_size(
+pub fn calculate_safe_batch_size(
     current: usize,
     available: usize,
 ) -> usize {
diff --git a/src/core/raft_role/learner_state.rs b/d-engine-core/src/raft_role/learner_state.rs
similarity index 96%
rename from src/core/raft_role/learner_state.rs
rename to d-engine-core/src/raft_role/learner_state.rs
index 29e66d04..1f827dd2 100644
--- a/src/core/raft_role/learner_state.rs
+++ b/d-engine-core/src/raft_role/learner_state.rs
@@ -5,34 +5,20 @@ use std::time::Duration;
 
 use tokio::sync::mpsc::{self};
 use tokio::time::Instant;
-use tonic::async_trait;
 use tonic::Status;
+use tonic::async_trait;
 use tracing::debug;
 use tracing::error;
 use tracing::info;
 use tracing::trace;
 use tracing::warn;
 
-use super::candidate_state::CandidateState;
-use super::follower_state::FollowerState;
-use super::role_state::RaftRoleState;
 use super::RaftRole;
 use super::SharedState;
 use super::StateSnapshot;
-use super::LEARNER;
-use crate::alias::MOF;
-use crate::proto::client::ClientResponse;
-use crate::proto::cluster::ClusterConfUpdateResponse;
-use crate::proto::cluster::JoinRequest;
-use crate::proto::cluster::LeaderDiscoveryRequest;
-use crate::proto::cluster::LeaderDiscoveryResponse;
-use crate::proto::common::LogId;
-use crate::proto::election::VoteResponse;
-use crate::proto::election::VotedFor;
-use crate::proto::error::ErrorCode;
-use crate::proto::storage::snapshot_ack::ChunkStatus;
-use crate::proto::storage::SnapshotAck;
-use crate::proto::storage::SnapshotResponse;
+use super::candidate_state::CandidateState;
+use super::follower_state::FollowerState;
+use super::role_state::RaftRoleState;
 use crate::ConsensusError;
 use crate::Membership;
 use crate::MembershipError;
@@ -47,6 +33,20 @@ use crate::StateMachineHandler;
 use crate::StateTransitionError;
 use crate::Transport;
 use crate::TypeConfig;
+use crate::alias::MOF;
+use d_engine_proto::client::ClientResponse;
+use d_engine_proto::common::LogId;
+use d_engine_proto::common::NodeRole::Learner;
+use d_engine_proto::error::ErrorCode;
+use d_engine_proto::server::cluster::ClusterConfUpdateResponse;
+use d_engine_proto::server::cluster::JoinRequest;
+use d_engine_proto::server::cluster::LeaderDiscoveryRequest;
+use d_engine_proto::server::cluster::LeaderDiscoveryResponse;
+use d_engine_proto::server::election::VoteResponse;
+use d_engine_proto::server::election::VotedFor;
+use d_engine_proto::server::storage::SnapshotAck;
+use d_engine_proto::server::storage::SnapshotResponse;
+use d_engine_proto::server::storage::snapshot_ack::ChunkStatus;
 
 /// Learner node's state in Raft cluster.
 ///
@@ -344,7 +344,7 @@ impl<T: TypeConfig> RaftRoleState for LearnerState<T> {
                     required_role: "Leader",
                     context: format!("Learner node {} attempted to create snapshot.", ctx.node_id),
                 }
-                .into())
+                .into());
             }
 
             RaftEvent::SnapshotCreated(_result) => {
@@ -356,7 +356,7 @@ impl<T: TypeConfig> RaftRoleState for LearnerState<T> {
                         ctx.node_id
                     ),
                 }
-                .into())
+                .into());
             }
 
             RaftEvent::LogPurgeCompleted(_purged_id) => {
@@ -368,7 +368,7 @@ impl<T: TypeConfig> RaftRoleState for LearnerState<T> {
                         ctx.node_id
                     ),
                 }
-                .into())
+                .into());
             }
 
             RaftEvent::JoinCluster(_join_request, sender) => {
@@ -472,7 +472,7 @@ impl<T: TypeConfig> RaftRoleState for LearnerState<T> {
                 leader_id,
                 JoinRequest {
                     node_id: node_config.cluster.node_id,
-                    node_role: LEARNER,
+                    node_role: Learner.into(),
                     address: node_config.cluster.listen_address.to_string(),
                 },
                 node_config.retry.join_cluster,
@@ -537,7 +537,7 @@ impl<T: TypeConfig> LearnerState<T> {
             current_term: self.current_term(),
             voted_for: None,
             commit_index: self.commit_index(),
-            role: LEARNER,
+            role: Learner.into(),
         }
     }
 }
@@ -554,7 +554,7 @@ impl<T: TypeConfig> LearnerState<T> {
         }
     }
 
-    pub(crate) async fn broadcast_discovery(
+    pub async fn broadcast_discovery(
         &self,
         membership: Arc<MOF<T>>,
         ctx: &RaftContext<T>,
@@ -627,7 +627,7 @@ impl<T: TypeConfig> LearnerState<T> {
     }
 
     /// @return Option<(leader_id, Channel)>
-    pub(super) async fn select_valid_leader(
+    pub async fn select_valid_leader(
         &self,
         responses: Vec<LeaderDiscoveryResponse>,
     ) -> Option<u32> {
diff --git a/src/core/raft_role/mod.rs b/d-engine-core/src/raft_role/mod.rs
similarity index 91%
rename from src/core/raft_role/mod.rs
rename to d-engine-core/src/raft_role/mod.rs
index 69b9f5cc..70644627 100644
--- a/src/core/raft_role/mod.rs
+++ b/d-engine-core/src/raft_role/mod.rs
@@ -4,33 +4,17 @@ pub mod leader_state;
 pub mod learner_state;
 pub mod role_state;
 
-#[cfg(test)]
-mod candidate_state_test;
-#[cfg(test)]
-mod follower_state_test;
-#[cfg(test)]
-mod leader_state_test;
-#[cfg(test)]
-mod learner_state_test;
-
-//---------------------------------------------------------------------
-pub const FOLLOWER: i32 = 0;
-pub const CANDIDATE: i32 = 1;
-pub const LEADER: i32 = 2;
-pub const LEARNER: i32 = 3;
-
-use std::collections::HashMap;
-
 use candidate_state::CandidateState;
 use follower_state::FollowerState;
 use leader_state::LeaderState;
 use learner_state::LearnerState;
 use role_state::RaftRoleState;
-use serde::ser::SerializeStruct;
 use serde::Deserialize;
 use serde::Deserializer;
 use serde::Serialize;
 use serde::Serializer;
+use serde::ser::SerializeStruct;
+use std::collections::HashMap;
 use tokio::sync::mpsc;
 use tokio::time::Instant;
 use tracing::debug;
@@ -39,11 +23,11 @@ use tracing::trace;
 use super::RaftContext;
 use super::RaftEvent;
 use super::RoleEvent;
-use crate::proto::client::ClientReadRequest;
-use crate::proto::common::EntryPayload;
-use crate::proto::election::VotedFor;
 use crate::Result;
 use crate::TypeConfig;
+use d_engine_proto::client::ClientReadRequest;
+use d_engine_proto::common::EntryPayload;
+use d_engine_proto::server::election::VotedFor;
 
 /// The role state focuses solely on its own logic
 /// and does not directly manipulate the underlying storage or network.
@@ -201,7 +185,7 @@ impl<T: TypeConfig> RaftRole<T> {
 
     #[allow(dead_code)]
     #[inline]
-    pub(crate) fn as_i32(&self) -> i32 {
+    pub fn as_i32(&self) -> i32 {
         match self {
             RaftRole::Follower(_) => 0,
             RaftRole::Candidate(_) => 1,
@@ -239,29 +223,29 @@ impl<T: TypeConfig> RaftRole<T> {
         self.state().is_learner()
     }
 
-    pub(crate) fn current_term(&self) -> u64 {
+    pub fn current_term(&self) -> u64 {
         self.state().current_term()
     }
 
     #[allow(dead_code)]
-    #[cfg(test)]
-    pub(crate) fn voted_for(&self) -> Result<Option<VotedFor>> {
+    #[cfg(any(test, feature = "test-utils"))]
+    pub fn voted_for(&self) -> Result<Option<VotedFor>> {
         self.state().voted_for()
     }
     #[allow(dead_code)]
-    #[cfg(test)]
-    pub(crate) fn commit_index(&self) -> u64 {
+    #[cfg(any(test, feature = "test-utils"))]
+    pub fn commit_index(&self) -> u64 {
         self.state().commit_index()
     }
-    #[cfg(test)]
-    pub(crate) fn match_index(
+    #[cfg(any(test, feature = "test-utils"))]
+    pub fn match_index(
         &self,
         node_id: u32,
     ) -> Option<u64> {
         self.state().match_index(node_id)
     }
-    #[cfg(test)]
-    pub(crate) fn next_index(
+    #[cfg(any(test, feature = "test-utils"))]
+    pub fn next_index(
         &self,
         node_id: u32,
     ) -> Option<u64> {
@@ -301,8 +285,8 @@ impl<T: TypeConfig> RaftRole<T> {
         self.state_mut().handle_raft_event(raft_event, ctx, role_tx).await
     }
 
-    #[cfg(test)]
-    pub(crate) fn follower_role_i32() -> i32 {
+    #[cfg(any(test, feature = "test-utils"))]
+    pub fn follower_role_i32() -> i32 {
         0
     }
 
@@ -355,14 +339,14 @@ impl<'de> Deserialize<'de> for HardState {
 }
 
 #[derive(Debug, PartialEq)]
-pub(crate) enum QuorumVerificationResult {
+pub enum QuorumVerificationResult {
     Success,        // Leadership confirmation successful
     LeadershipLost, // Confirmation of leadership loss (need to abdicate)
     RetryRequired,  // Retry required (leadership still exists)
 }
 
 use crate::config::ReadConsistencyPolicy as ServerReadConsistencyPolicy;
-use crate::proto::client::ReadConsistencyPolicy as ClientReadConsistencyPolicy;
+use d_engine_proto::client::ReadConsistencyPolicy as ClientReadConsistencyPolicy;
 
 /// Checks if non-leader node can serve read request locally
 ///
diff --git a/src/core/raft_role/role_state.rs b/d-engine-core/src/raft_role/role_state.rs
similarity index 96%
rename from src/core/raft_role/role_state.rs
rename to d-engine-core/src/raft_role/role_state.rs
index c9f6552a..112bc600 100644
--- a/src/core/raft_role/role_state.rs
+++ b/d-engine-core/src/raft_role/role_state.rs
@@ -1,7 +1,7 @@
 use tokio::sync::mpsc;
 use tokio::time::Instant;
-use tonic::async_trait;
 use tonic::Status;
+use tonic::async_trait;
 use tracing::debug;
 use tracing::error;
 use tracing::warn;
@@ -9,12 +9,6 @@ use tracing::warn;
 use super::RaftRole;
 use super::SharedState;
 use super::StateSnapshot;
-use crate::proto::common::EntryPayload;
-use crate::proto::election::VotedFor;
-use crate::proto::replication::AppendEntriesRequest;
-use crate::proto::replication::AppendEntriesResponse;
-use crate::scoped_timer::ScopedTimer;
-use crate::utils::cluster::error;
 use crate::AppendResponseWithUpdates;
 use crate::MaybeCloneOneshotSender;
 use crate::Membership;
@@ -30,9 +24,15 @@ use crate::Result;
 use crate::RoleEvent;
 use crate::StateTransitionError;
 use crate::TypeConfig;
+use crate::scoped_timer::ScopedTimer;
+use crate::utils::cluster::error;
+use d_engine_proto::common::EntryPayload;
+use d_engine_proto::server::election::VotedFor;
+use d_engine_proto::server::replication::AppendEntriesRequest;
+use d_engine_proto::server::replication::AppendEntriesResponse;
 
 #[async_trait]
-pub(crate) trait RaftRoleState: Send + Sync + 'static {
+pub trait RaftRoleState: Send + Sync + 'static {
     type T: TypeConfig;
 
     //--- For sharing state behaviors
@@ -395,7 +395,9 @@ pub(crate) trait RaftRoleState: Send + Sync + 'static {
                 // Conservatively fallback to a safe position, forcing the leader to retry or
                 // trigger a snapshot. Return a Conflict response (conflict index =
                 // current log length + 1)
-                error!("Replication failed. Conservatively fallback to a safe position, forcing the leader to retry");
+                error!(
+                    "Replication failed. Conservatively fallback to a safe position, forcing the leader to retry"
+                );
                 let response = AppendEntriesResponse::conflict(
                     self.node_id(),
                     my_term,
diff --git a/src/core/replication/batch_buffer.rs b/d-engine-core/src/replication/batch_buffer.rs
similarity index 100%
rename from src/core/replication/batch_buffer.rs
rename to d-engine-core/src/replication/batch_buffer.rs
diff --git a/src/core/replication/batch_buffer_test.rs b/d-engine-core/src/replication/batch_buffer_test.rs
similarity index 100%
rename from src/core/replication/batch_buffer_test.rs
rename to d-engine-core/src/replication/batch_buffer_test.rs
diff --git a/src/core/replication/mod.rs b/d-engine-core/src/replication/mod.rs
similarity index 77%
rename from src/core/replication/mod.rs
rename to d-engine-core/src/replication/mod.rs
index da58e047..83268ee0 100644
--- a/src/core/replication/mod.rs
+++ b/d-engine-core/src/replication/mod.rs
@@ -12,8 +12,6 @@ pub use replication_handler::*;
 
 #[cfg(test)]
 mod batch_buffer_test;
-#[cfg(test)]
-mod replication_handler_test;
 
 // Client Request Extension Definition
 // -----------------------------------------------------------------------------
@@ -21,27 +19,25 @@ use std::collections::HashMap;
 use std::sync::Arc;
 
 use dashmap::DashMap;
-#[cfg(test)]
+#[cfg(any(test, feature = "test-utils"))]
 use mockall::automock;
-use tonic::async_trait;
 use tonic::Status;
+use tonic::async_trait;
 
 use super::LeaderStateSnapshot;
 use super::StateSnapshot;
-use crate::alias::ROF;
-use crate::proto::client::ClientResponse;
-use crate::proto::common::Entry;
-use crate::proto::common::EntryPayload;
-use crate::proto::common::LogId;
-use crate::proto::replication::append_entries_response;
-use crate::proto::replication::AppendEntriesRequest;
-use crate::proto::replication::AppendEntriesResponse;
-use crate::proto::replication::ConflictResult;
-use crate::proto::replication::SuccessResult;
 use crate::AppendResults;
 use crate::MaybeCloneOneshotSender;
 use crate::Result;
 use crate::TypeConfig;
+use crate::alias::ROF;
+use d_engine_proto::client::ClientResponse;
+use d_engine_proto::common::Entry;
+use d_engine_proto::common::EntryPayload;
+use d_engine_proto::server::replication::AppendEntriesRequest;
+use d_engine_proto::server::replication::AppendEntriesResponse;
+use d_engine_proto::server::replication::ConflictResult;
+use d_engine_proto::server::replication::SuccessResult;
 
 /// Request with response channel that can handle all Raft payload types
 #[derive(Debug)]
@@ -60,7 +56,7 @@ pub struct AppendResponseWithUpdates {
 }
 
 /// Core replication protocol operations
-#[cfg_attr(test, automock)]
+#[cfg_attr(any(test, feature = "test-utils"), automock)]
 #[async_trait]
 pub trait ReplicationCore<T>: Send + Sync + 'static
 where
@@ -221,73 +217,3 @@ where
         raft_log: &Arc<ROF<T>>,
     ) -> AppendEntriesResponse;
 }
-
-impl AppendEntriesResponse {
-    /// Generate a successful response (full success)
-    pub fn success(
-        node_id: u32,
-        term: u64,
-        last_match: Option<LogId>,
-    ) -> Self {
-        Self {
-            node_id,
-            term,
-            result: Some(append_entries_response::Result::Success(SuccessResult {
-                last_match,
-            })),
-        }
-    }
-
-    /// Generate conflict response (with conflict details)
-    pub fn conflict(
-        node_id: u32,
-        term: u64,
-        conflict_term: Option<u64>,
-        conflict_index: Option<u64>,
-    ) -> Self {
-        Self {
-            node_id,
-            term,
-            result: Some(append_entries_response::Result::Conflict(ConflictResult {
-                conflict_term,
-                conflict_index,
-            })),
-        }
-    }
-
-    /// Generate a conflict response (Higher term found)
-    pub fn higher_term(
-        node_id: u32,
-        term: u64,
-    ) -> Self {
-        Self {
-            node_id,
-            term,
-            result: Some(append_entries_response::Result::HigherTerm(term)),
-        }
-    }
-
-    /// Check if it is a success response
-    pub fn is_success(&self) -> bool {
-        matches!(
-            &self.result,
-            Some(append_entries_response::Result::Success(_))
-        )
-    }
-
-    /// Check if it is a conflict response
-    pub fn is_conflict(&self) -> bool {
-        matches!(
-            &self.result,
-            Some(append_entries_response::Result::Conflict(_conflict))
-        )
-    }
-
-    /// Check if it is a response of a higher Term
-    pub fn is_higher_term(&self) -> bool {
-        matches!(
-            &self.result,
-            Some(append_entries_response::Result::HigherTerm(_))
-        )
-    }
-}
diff --git a/src/core/replication/replication_handler.rs b/d-engine-core/src/replication/replication_handler.rs
similarity index 95%
rename from src/core/replication/replication_handler.rs
rename to d-engine-core/src/replication/replication_handler.rs
index 506aa138..4ddc288e 100644
--- a/src/core/replication/replication_handler.rs
+++ b/d-engine-core/src/replication/replication_handler.rs
@@ -16,20 +16,6 @@ use tracing::warn;
 
 use super::AppendResponseWithUpdates;
 use super::ReplicationCore;
-use crate::alias::ROF;
-use crate::proto::client::WriteCommand;
-use crate::proto::common::entry_payload::Payload;
-use crate::proto::common::Entry;
-use crate::proto::common::EntryPayload;
-use crate::proto::common::LogId;
-use crate::proto::common::NodeStatus;
-use crate::proto::replication::append_entries_response;
-use crate::proto::replication::AppendEntriesRequest;
-use crate::proto::replication::AppendEntriesResponse;
-use crate::proto::replication::ConflictResult;
-use crate::proto::replication::SuccessResult;
-use crate::scoped_timer::ScopedTimer;
-use crate::utils::cluster::is_majority;
 use crate::AppendResults;
 use crate::IdAllocationError;
 use crate::LeaderStateSnapshot;
@@ -42,6 +28,20 @@ use crate::Result;
 use crate::StateSnapshot;
 use crate::Transport;
 use crate::TypeConfig;
+use crate::alias::ROF;
+use crate::scoped_timer::ScopedTimer;
+use crate::utils::cluster::is_majority;
+use d_engine_proto::client::WriteCommand;
+use d_engine_proto::common::Entry;
+use d_engine_proto::common::EntryPayload;
+use d_engine_proto::common::LogId;
+use d_engine_proto::common::NodeStatus;
+use d_engine_proto::common::entry_payload::Payload;
+use d_engine_proto::server::replication::AppendEntriesRequest;
+use d_engine_proto::server::replication::AppendEntriesResponse;
+use d_engine_proto::server::replication::ConflictResult;
+use d_engine_proto::server::replication::SuccessResult;
+use d_engine_proto::server::replication::append_entries_response;
 
 #[derive(Clone)]
 pub struct ReplicationHandler<T>
@@ -90,8 +90,7 @@ where
         if !learners.is_empty() {
             trace!(
                 "handle_raft_request_in_batch - voters: {:?}, learners: {:?}",
-                voters,
-                learners
+                voters, learners
             );
         }
 
@@ -514,11 +513,11 @@ where
 }
 
 #[derive(Debug)]
-pub(super) struct ReplicationData {
-    pub(super) leader_last_index_before: u64,
-    pub(super) current_term: u64,
-    pub(super) commit_index: u64,
-    pub(super) peer_next_indices: HashMap<u32, u64>,
+pub struct ReplicationData {
+    pub leader_last_index_before: u64,
+    pub current_term: u64,
+    pub commit_index: u64,
+    pub peer_next_indices: HashMap<u32, u64>,
 }
 
 impl<T> ReplicationHandler<T>
@@ -534,7 +533,7 @@ where
 
     /// Generate a new log entry
     ///     including insert them into local raft log
-    pub(super) async fn generate_new_entries(
+    pub async fn generate_new_entries(
         &self,
         entry_payloads: Vec<EntryPayload>,
         current_term: u64,
@@ -587,7 +586,7 @@ where
     }
 
     /// Prepare the items that need to be synchronized for each node
-    pub(super) fn prepare_peer_entries(
+    pub fn prepare_peer_entries(
         &self,
         new_entries: &[Entry],
         data: &ReplicationData,
@@ -604,7 +603,7 @@ where
     }
 
     /// Build an append request for a single node
-    pub(super) fn build_append_request(
+    pub fn build_append_request(
         &self,
         raft_log: &Arc<ROF<T>>,
         peer_id: u32,
@@ -664,7 +663,7 @@ where
 ///
 /// # Returns
 /// A vector of EntryPayload containing the serialized commands
-pub(crate) fn client_command_to_entry_payloads(commands: Vec<WriteCommand>) -> Vec<EntryPayload> {
+pub fn client_command_to_entry_payloads(commands: Vec<WriteCommand>) -> Vec<EntryPayload> {
     commands
         .into_iter()
         .map(|cmd| {
diff --git a/src/core/state_machine_handler/default_state_machine_handler.rs b/d-engine-core/src/state_machine_handler/default_state_machine_handler.rs
similarity index 97%
rename from src/core/state_machine_handler/default_state_machine_handler.rs
rename to d-engine-core/src/state_machine_handler/default_state_machine_handler.rs
index 8f4d7b77..68c69e7b 100644
--- a/src/core/state_machine_handler/default_state_machine_handler.rs
+++ b/d-engine-core/src/state_machine_handler/default_state_machine_handler.rs
@@ -1,10 +1,10 @@
 use std::ops::RangeInclusive;
 use std::path::Path;
 use std::path::PathBuf;
+use std::sync::Arc;
 use std::sync::atomic::AtomicBool;
 use std::sync::atomic::AtomicU64;
 use std::sync::atomic::Ordering;
-use std::sync::Arc;
 use std::time::Duration;
 
 use async_compression::tokio::bufread::GzipDecoder;
@@ -16,20 +16,20 @@ use memmap2::Mmap;
 use memmap2::MmapOptions;
 use tempfile::tempdir;
 use tokio::fs;
+use tokio::fs::File;
 use tokio::fs::remove_dir_all;
 use tokio::fs::remove_file;
-use tokio::fs::File;
 use tokio::io::AsyncReadExt;
 use tokio::io::AsyncWriteExt;
 use tokio::io::BufReader;
-use tokio::sync::mpsc;
 use tokio::sync::RwLock;
-use tokio::time::timeout;
+use tokio::sync::mpsc;
 use tokio::time::Instant;
+use tokio::time::timeout;
 use tokio_stream::StreamExt;
 use tokio_tar::Archive;
-use tonic::async_trait;
 use tonic::Streaming;
+use tonic::async_trait;
 use tracing::debug;
 use tracing::error;
 use tracing::info;
@@ -40,23 +40,6 @@ use super::SnapshotAssembler;
 use super::SnapshotContext;
 use super::SnapshotPolicy;
 use super::StateMachineHandler;
-use crate::alias::ROF;
-use crate::alias::SMOF;
-use crate::alias::SNP;
-use crate::constants::SNAPSHOT_DIR_PREFIX;
-use crate::convert::classify_error;
-use crate::file_io::validate_checksum;
-use crate::file_io::validate_compressed_format;
-use crate::proto::client::ClientResult;
-use crate::proto::common::Entry;
-use crate::proto::common::LogId;
-use crate::proto::storage::snapshot_ack::ChunkStatus;
-use crate::proto::storage::PurgeLogRequest;
-use crate::proto::storage::PurgeLogResponse;
-use crate::proto::storage::SnapshotAck;
-use crate::proto::storage::SnapshotChunk;
-use crate::proto::storage::SnapshotMetadata;
-use crate::scoped_timer::ScopedTimer;
 use crate::NewCommitData;
 use crate::RaftLog;
 use crate::Result;
@@ -67,6 +50,22 @@ use crate::SnapshotPathManager;
 use crate::StateMachine;
 use crate::StorageError;
 use crate::TypeConfig;
+use crate::alias::ROF;
+use crate::alias::SMOF;
+use crate::alias::SNP;
+use crate::convert::classify_error;
+use crate::file_io::validate_checksum;
+use crate::file_io::validate_compressed_format;
+use crate::scoped_timer::ScopedTimer;
+use d_engine_proto::client::ClientResult;
+use d_engine_proto::common::Entry;
+use d_engine_proto::common::LogId;
+use d_engine_proto::server::storage::PurgeLogRequest;
+use d_engine_proto::server::storage::PurgeLogResponse;
+use d_engine_proto::server::storage::SnapshotAck;
+use d_engine_proto::server::storage::SnapshotChunk;
+use d_engine_proto::server::storage::SnapshotMetadata;
+use d_engine_proto::server::storage::snapshot_ack::ChunkStatus;
 
 /// Unified snapshot metadata with precomputed values
 #[derive(Debug, Clone)]
@@ -170,9 +169,7 @@ where
         let last_index = chunk.last().map(|entry| entry.index);
         trace!(
             "[node-{}] apply_chunk::entry={:?} last_index: {:?}",
-            self.node_id,
-            &chunk,
-            last_index
+            self.node_id, &chunk, last_index
         );
 
         let sm = self.state_machine.clone();
@@ -360,6 +357,7 @@ where
             .cleanup_snapshot(
                 self.snapshot_config.cleanup_retain_count,
                 &self.snapshot_config.snapshots_dir,
+                &self.snapshot_config.snapshots_dir_prefix,
             )
             .await
         {
@@ -382,6 +380,7 @@ where
         &self,
         retain_count: u64,
         snapshot_dir: &Path,
+        snapshot_dir_prefix: &str,
     ) -> Result<()> {
         // Phase 1: Collect and parse snapshots
         let mut snapshots = Vec::new();
@@ -398,9 +397,12 @@ where
 
             if path.extension().is_some_and(|ext| ext == "gz") {
                 if let Some(file_name) = path.file_name().and_then(|n| n.to_str()) {
-                    let parsed = parse_snapshot_dirname(file_name).or_else(|| {
-                        file_name.strip_suffix(".tar.gz").and_then(parse_snapshot_dirname)
-                    });
+                    let parsed =
+                        parse_snapshot_dirname(file_name, snapshot_dir_prefix).or_else(|| {
+                            file_name
+                                .strip_suffix(".tar.gz")
+                                .and_then(|s| parse_snapshot_dirname(s, snapshot_dir_prefix))
+                        });
 
                     let (index, term) = if let Some(pair) = parsed {
                         pair
@@ -700,7 +702,7 @@ where
             snapshot_policy,
             path_mgr: Arc::new(SnapshotPathManager::new(
                 snapshot_config.snapshots_dir.clone(),
-                SNAPSHOT_DIR_PREFIX.to_string(),
+                snapshot_config.snapshots_dir_prefix.clone(),
             )),
             snapshot_config,
 
@@ -1110,11 +1112,14 @@ fn zero_copy_bytes_from_mmap(
 }
 
 /// Manual parsing file name format: snapshot-{index}-{term}
-fn parse_snapshot_dirname(name: &str) -> Option<(u64, u64)> {
+fn parse_snapshot_dirname(
+    name: &str,
+    snapshot_dir_prefix: &str,
+) -> Option<(u64, u64)> {
     debug!(%name, "parse_snapshot_dirname");
 
     // Check prefix and suffix
-    if !name.starts_with(SNAPSHOT_DIR_PREFIX) {
+    if !name.starts_with(snapshot_dir_prefix) {
         return None;
     }
 
diff --git a/src/core/state_machine_handler/default_state_machine_handler_test.rs b/d-engine-core/src/state_machine_handler/default_state_machine_handler_test.rs
similarity index 86%
rename from src/core/state_machine_handler/default_state_machine_handler_test.rs
rename to d-engine-core/src/state_machine_handler/default_state_machine_handler_test.rs
index 94a70ae0..414184fd 100644
--- a/src/core/state_machine_handler/default_state_machine_handler_test.rs
+++ b/d-engine-core/src/state_machine_handler/default_state_machine_handler_test.rs
@@ -1,62 +1,43 @@
-use std::collections::HashMap;
+use bytes::Bytes;
+use futures::StreamExt;
+use mockall::Sequence;
+use mockall::predicate::eq;
 use std::collections::HashSet;
 use std::fs;
-use std::net::SocketAddr;
 use std::path::Path;
 use std::path::PathBuf;
 use std::sync::Arc;
 use std::time::Duration;
-
-use bytes::Bytes;
-use futures::StreamExt;
-use mockall::predicate::eq;
-use mockall::Sequence;
-use tempfile::tempdir;
 use tempfile::TempDir;
-use tokio::fs::create_dir_all;
+use tempfile::tempdir;
 use tokio::fs::File;
+use tokio::fs::create_dir_all;
 use tokio::io::AsyncWriteExt;
 use tokio::sync::mpsc;
-use tokio::sync::watch;
-use tokio::time;
 use tracing::debug;
 use tracing_test::traced_test;
 
 use super::DefaultStateMachineHandler;
-use super::MockStateMachineHandler;
 use super::StateMachineHandler;
-use crate::constants::SNAPSHOT_DIR_PREFIX;
-use crate::proto::cluster::NodeMeta;
-use crate::proto::common::Entry;
-use crate::proto::common::LogId;
-use crate::proto::election::VotedFor;
-use crate::proto::storage::snapshot_ack::ChunkStatus;
-use crate::proto::storage::snapshot_service_client::SnapshotServiceClient;
-use crate::proto::storage::PurgeLogRequest;
-use crate::proto::storage::SnapshotAck;
-use crate::proto::storage::SnapshotChunk;
-use crate::proto::storage::SnapshotMetadata;
-use crate::test_utils::crate_test_snapshot_stream;
-use crate::test_utils::create_test_chunk;
-use crate::test_utils::create_test_compressed_snapshot;
-use crate::test_utils::node_config;
-use crate::test_utils::snapshot_config;
-use crate::test_utils::MockBuilder;
-use crate::test_utils::MockTypeConfig;
-use crate::test_utils::MOCK_STATE_MACHINE_HANDLER_PORT_BASE;
-use crate::AppendResults;
 use crate::ConsensusError;
-use crate::ElectionError;
 use crate::Error;
-use crate::MockElectionCore;
 use crate::MockRaftLog;
-use crate::MockReplicationCore;
 use crate::MockSnapshotPolicy;
 use crate::MockStateMachine;
-use crate::Node;
+use crate::MockTypeConfig;
 use crate::SnapshotError;
-use crate::StateUpdate;
 use crate::StorageError;
+use crate::test_utils::create_test_chunk;
+use crate::test_utils::create_test_compressed_snapshot;
+use crate::test_utils::create_test_snapshot_stream;
+use crate::test_utils::snapshot_config;
+use d_engine_proto::common::Entry;
+use d_engine_proto::common::LogId;
+use d_engine_proto::server::storage::PurgeLogRequest;
+use d_engine_proto::server::storage::SnapshotAck;
+use d_engine_proto::server::storage::SnapshotChunk;
+use d_engine_proto::server::storage::SnapshotMetadata;
+use d_engine_proto::server::storage::snapshot_ack::ChunkStatus;
 
 // Case 1: normal update
 #[test]
@@ -326,75 +307,75 @@ mod apply_chunk_test {
     }
 }
 
-fn listen_addr(port: u32) -> SocketAddr {
-    format!("127.0.0.1:{port}",).parse().unwrap()
-}
-
-/// Case1: Complete successful snapshot installation
-#[tokio::test]
-#[traced_test]
-async fn test_install_snapshot_case1() {
-    let port = MOCK_STATE_MACHINE_HANDLER_PORT_BASE + 1;
-    // 1. Simulate node with RPC server running in a new thread
-    let (graceful_tx, graceful_rx) = watch::channel(());
-    let node = mock_node_with_rpc_service(
-        "/tmp/test_install_snapshot_case1",
-        listen_addr(port),
-        false,
-        graceful_rx,
-        None,
-    );
-    node.set_ready(true);
-
-    // 3. Start the Raft main loop
-    let raft_handle = tokio::spawn(async move {
-        let mut raft = node.raft_core.lock().await;
-        let _ = time::timeout(Duration::from_millis(100), raft.run()).await;
-    });
-
-    // 2. Crate RPC client
-    let addr: SocketAddr = format!("[::]:{port}",).parse().unwrap();
-    let mut rpc_client = SnapshotServiceClient::connect(format!(
-        "grpc://localhost:{}",
-        addr.to_string().split(':').next_back().unwrap()
-    ))
-    .await
-    .unwrap();
-
-    // 3. Fake install snapshot request stream
-    let total_chunks = 3;
-    let (tx, rx) = tokio::sync::mpsc::channel(10);
-    // Generate valid chunks with seq 0..2
-    let h = tokio::spawn(async move {
-        for seq in 0..total_chunks {
-            let chunk = create_test_chunk(
-                seq,
-                &format!("chunk-{seq}",).into_bytes(),
-                3, // chunk term (higher than handler's current_term)
-                1, // leader_id
-                total_chunks,
-            );
-
-            tx.send(chunk).await.expect("send failed");
-        }
-    });
-    // Convert mpsc receiver into tonic::Streaming
-    let request_stream = tokio_stream::wrappers::ReceiverStream::new(rx);
-
-    // 4. Waiting to receive response
-    tokio::time::sleep(Duration::from_millis(20)).await;
-
-    let response = rpc_client.install_snapshot(request_stream).await.unwrap().into_inner();
-
-    assert!(response.success);
-    assert_eq!(response.term, 1); // Should reflect handler's current_term
-    assert_eq!(response.next_chunk, 0); // Indicates full success
-
-    // Release handler
-    graceful_tx.send(()).expect("shutdown successfully!");
-    raft_handle.await.expect("should succeed");
-    h.await.unwrap();
-}
+// fn listen_addr(port: u32) -> SocketAddr {
+//     format!("127.0.0.1:{port}",).parse().unwrap()
+// }
+
+// /// Case1: Complete successful snapshot installation
+// #[tokio::test]
+// #[traced_test]
+// async fn test_install_snapshot_case1() {
+//     let port = MOCK_STATE_MACHINE_HANDLER_PORT_BASE + 1;
+//     // 1. Simulate node with RPC server running in a new thread
+//     let (graceful_tx, graceful_rx) = watch::channel(());
+//     let node = mock_node_with_rpc_service(
+//         "/tmp/test_install_snapshot_case1",
+//         listen_addr(port),
+//         false,
+//         graceful_rx,
+//         None,
+//     );
+//     node.set_ready(true);
+
+//     // 3. Start the Raft main loop
+//     let raft_handle = tokio::spawn(async move {
+//         let mut raft = node.raft_core.lock().await;
+//         let _ = time::timeout(Duration::from_millis(100), raft.run()).await;
+//     });
+
+//     // 2. Crate RPC client
+//     let addr: SocketAddr = format!("[::]:{port}",).parse().unwrap();
+//     let mut rpc_client = SnapshotServiceClient::connect(format!(
+//         "grpc://localhost:{}",
+//         addr.to_string().split(':').next_back().unwrap()
+//     ))
+//     .await
+//     .unwrap();
+
+//     // 3. Fake install snapshot request stream
+//     let total_chunks = 3;
+//     let (tx, rx) = tokio::sync::mpsc::channel(10);
+//     // Generate valid chunks with seq 0..2
+//     let h = tokio::spawn(async move {
+//         for seq in 0..total_chunks {
+//             let chunk = create_test_chunk(
+//                 seq,
+//                 &format!("chunk-{seq}",).into_bytes(),
+//                 3, // chunk term (higher than handler's current_term)
+//                 1, // leader_id
+//                 total_chunks,
+//             );
+
+//             tx.send(chunk).await.expect("send failed");
+//         }
+//     });
+//     // Convert mpsc receiver into tonic::Streaming
+//     let request_stream = tokio_stream::wrappers::ReceiverStream::new(rx);
+
+//     // 4. Waiting to receive response
+//     tokio::time::sleep(Duration::from_millis(20)).await;
+
+//     let response = rpc_client.install_snapshot(request_stream).await.unwrap().into_inner();
+
+//     assert!(response.success);
+//     assert_eq!(response.term, 1); // Should reflect handler's current_term
+//     assert_eq!(response.next_chunk, 0); // Indicates full success
+
+//     // Release handler
+//     graceful_tx.send(()).expect("shutdown successfully!");
+//     raft_handle.await.expect("should succeed");
+//     h.await.unwrap();
+// }
 
 // Helper to create test handler
 fn create_test_handler(
@@ -473,7 +454,7 @@ async fn test_apply_snapshot_stream_from_leader_case2() {
     };
     chunks.push(chunk);
 
-    let streaming_request = crate_test_snapshot_stream(chunks);
+    let streaming_request = create_test_snapshot_stream(chunks);
     let (ack_tx, mut ack_rx) = mpsc::channel::<SnapshotAck>(1);
 
     // Spawn the handler in a separate task to prevent deadlock
@@ -512,7 +493,7 @@ async fn test_apply_snapshot_stream_from_leader_case3() {
 
     // Create ACK channel
     let (ack_tx, mut ack_rx) = mpsc::channel::<SnapshotAck>(1);
-    let stream = crate_test_snapshot_stream(vec![bad_chunk]);
+    let stream = create_test_snapshot_stream(vec![bad_chunk]);
 
     let handler_task = tokio::spawn({
         let config = snapshot_config(temp_path.to_path_buf());
@@ -549,7 +530,7 @@ async fn test_apply_snapshot_stream_from_leader_case4() {
     ];
 
     let (ack_tx, mut ack_rx) = mpsc::channel::<SnapshotAck>(1);
-    let stream = crate_test_snapshot_stream(chunks);
+    let stream = create_test_snapshot_stream(chunks);
 
     let handler_task = tokio::spawn({
         let config = snapshot_config(temp_path.to_path_buf());
@@ -591,7 +572,7 @@ async fn test_apply_snapshot_stream_from_leader_case5() {
         TEST_LEADER_ID,
         2,
     )];
-    let stream = crate_test_snapshot_stream(chunks);
+    let stream = create_test_snapshot_stream(chunks);
     let (ack_tx, mut ack_rx) = mpsc::channel::<SnapshotAck>(1);
 
     let handler_task = tokio::spawn({
@@ -627,7 +608,7 @@ async fn test_apply_snapshot_stream_from_leader_case6() {
     invalid_chunk.metadata = None;
 
     let (ack_tx, mut ack_rx) = mpsc::channel::<SnapshotAck>(1);
-    let stream = crate_test_snapshot_stream(vec![invalid_chunk]);
+    let stream = create_test_snapshot_stream(vec![invalid_chunk]);
 
     let handler_task = tokio::spawn({
         let config = snapshot_config(temp_path.to_path_buf());
@@ -699,7 +680,7 @@ async fn test_apply_snapshot_stream_from_leader_case7() {
         chunks.push(chunk);
     }
 
-    let streaming_request = crate_test_snapshot_stream(chunks);
+    let streaming_request = create_test_snapshot_stream(chunks);
     let (ack_tx, mut ack_rx) = mpsc::channel::<SnapshotAck>(1);
 
     // Spawn the handler in a separate task
@@ -728,7 +709,7 @@ async fn test_apply_snapshot_stream_from_leader_case7() {
 mod create_snapshot_tests {
     use super::*;
     use crate::NewCommitData;
-    use crate::LEADER;
+    use d_engine_proto::common::NodeRole::Leader;
     /// # Case 1: Basic creation flow
     #[tokio::test]
     async fn test_create_snapshot_case1() {
@@ -765,7 +746,7 @@ mod create_snapshot_tests {
             0,
             1,
             Arc::new(sm),
-            config,
+            config.clone(),
             MockSnapshotPolicy::new(),
         );
 
@@ -781,10 +762,12 @@ mod create_snapshot_tests {
         debug!(?final_path);
         assert!(final_path.is_file());
         assert!(final_path.extension().unwrap() == "gz");
-        assert!(final_path
-            .to_str()
-            .unwrap()
-            .contains(&format!("{SNAPSHOT_DIR_PREFIX}5-1.tar.gz",)));
+        assert!(
+            final_path
+                .to_str()
+                .unwrap()
+                .contains(&format!("{}5-1.tar.gz", &config.snapshots_dir_prefix))
+        );
 
         assert_eq!(metadata.last_included, Some(LogId { term: 1, index: 5 }));
     }
@@ -838,7 +821,7 @@ mod create_snapshot_tests {
             0,
             1,
             Arc::new(sm),
-            config,
+            config.clone(),
             snapshot_policy,
         ));
         tx.send(()).unwrap(); // Unblock the first task
@@ -868,11 +851,11 @@ mod create_snapshot_tests {
             success_count, 1,
             "Expected exactly one successful snapshot creation"
         );
-        assert_eq!(count_snapshots(&temp_path), 1);
+        assert_eq!(count_snapshots(&temp_path, &config.snapshots_dir_prefix), 1);
 
         // Verify flag is reset regardless of task outcome
         let ctx = NewCommitData {
-            role: LEADER,
+            role: Leader.into(),
             current_term: 1,
             new_commit_index: 100,
         };
@@ -912,7 +895,7 @@ mod create_snapshot_tests {
             3, // Current version
             1,
             Arc::new(sm),
-            config,
+            config.clone(),
             MockSnapshotPolicy::new(),
         );
 
@@ -929,7 +912,8 @@ mod create_snapshot_tests {
 
         // Verify files are compressed
         for version in &[3, 4] {
-            let path = snapshot_dir.join(format!("{SNAPSHOT_DIR_PREFIX}{version}-1.tar.gz",));
+            let path =
+                snapshot_dir.join(format!("{}{version}-1.tar.gz", config.snapshots_dir_prefix));
             assert!(path.is_file(), "Snapshot file not found: {path:?}",);
         }
     }
@@ -955,7 +939,7 @@ mod create_snapshot_tests {
             0,
             1,
             Arc::new(sm),
-            config,
+            config.clone(),
             MockSnapshotPolicy::new(),
         );
 
@@ -964,7 +948,7 @@ mod create_snapshot_tests {
         assert!(result.is_err());
 
         // Verify no files created
-        assert_eq!(count_snapshots(&temp_path), 0);
+        assert_eq!(count_snapshots(&temp_path, &config.snapshots_dir_prefix), 0);
     }
 
     /// # Case 5: Test snapshot_in_progress flag is reset on success
@@ -1037,7 +1021,10 @@ mod create_snapshot_tests {
 }
 
 // Helper functions
-fn count_snapshots(dir: &Path) -> usize {
+fn count_snapshots(
+    dir: &Path,
+    snapshots_dir_prefix: &str,
+) -> usize {
     debug!(?dir, "count_snapshots");
 
     // If the directory does not exist or cannot be accessed, just return 0
@@ -1053,7 +1040,7 @@ fn count_snapshots(dir: &Path) -> usize {
             entry
                 .file_name()
                 .to_str()
-                .and_then(|name| name.starts_with(SNAPSHOT_DIR_PREFIX).then_some(()))
+                .and_then(|name| name.starts_with(snapshots_dir_prefix).then_some(()))
         })
         .count()
 }
@@ -1089,18 +1076,22 @@ async fn test_cleanup_snapshot_case1() {
     let temp_dir = TempDir::new().unwrap();
     let sm = MockStateMachine::new();
 
-    create_test_files(&temp_dir, &[1, 2, 3]).await;
+    let config = snapshot_config(temp_dir.path().to_path_buf());
+    create_test_files(&temp_dir, &[1, 2, 3], &config.snapshots_dir_prefix).await;
 
     let handler = DefaultStateMachineHandler::<MockTypeConfig>::new(
         1,
         0,
         1,
         Arc::new(sm),
-        snapshot_config(temp_dir.path().to_path_buf()),
+        config.clone(),
         MockSnapshotPolicy::new(),
     );
 
-    handler.cleanup_snapshot(2, temp_dir.path()).await.unwrap();
+    handler
+        .cleanup_snapshot(2, temp_dir.path(), &config.snapshots_dir_prefix)
+        .await
+        .unwrap();
 
     // Verify remaining snapshots
     let mut remaining = get_snapshot_versions(temp_dir.path());
@@ -1111,7 +1102,10 @@ async fn test_cleanup_snapshot_case1() {
 
     // Verify files are compressed
     for version in &[2, 3] {
-        let path = temp_dir.path().join(format!("{SNAPSHOT_DIR_PREFIX}{version}-1.tar.gz"));
+        let path = temp_dir.path().join(format!(
+            "{}{}-1.tar.gz",
+            config.snapshots_dir_prefix, version
+        ));
         assert!(path.is_file(), "Snapshot file not found: {path:?}",);
     }
 }
@@ -1122,18 +1116,22 @@ async fn test_cleanup_snapshot_case1() {
 async fn test_cleanup_snapshot_case2() {
     let temp_dir = TempDir::new().unwrap();
     let sm = MockStateMachine::new();
-    create_test_files(&temp_dir, &[3, 4]).await;
+    let config = snapshot_config(temp_dir.path().to_path_buf());
+    create_test_files(&temp_dir, &[3, 4], &config.snapshots_dir_prefix).await;
 
     let handler = DefaultStateMachineHandler::<MockTypeConfig>::new(
         1,
         0,
         1,
         Arc::new(sm),
-        snapshot_config(temp_dir.path().to_path_buf()),
+        config.clone(),
         MockSnapshotPolicy::new(),
     );
 
-    handler.cleanup_snapshot(2, temp_dir.path()).await.unwrap();
+    handler
+        .cleanup_snapshot(2, temp_dir.path(), &config.snapshots_dir_prefix)
+        .await
+        .unwrap();
 
     // Verify no deletions
     let mut remaining = get_snapshot_versions(temp_dir.path());
@@ -1149,29 +1147,37 @@ async fn test_cleanup_snapshot_case2() {
 async fn test_cleanup_snapshot_case3() {
     let temp_dir = TempDir::new().unwrap();
     let sm = MockStateMachine::new();
+    let config = snapshot_config(temp_dir.path().to_path_buf());
     // Create valid and invalid directories
-    create_dir(&temp_dir, &format!("{SNAPSHOT_DIR_PREFIX}1-1",)).await;
+    create_dir(&temp_dir, &format!("{}1-1", &config.snapshots_dir_prefix)).await;
     create_dir(&temp_dir, "invalid_format").await;
-    create_dir(&temp_dir, &format!("{SNAPSHOT_DIR_PREFIX}bad-2-2",)).await;
+    create_dir(
+        &temp_dir,
+        &format!("{}bad-2-2", &config.snapshots_dir_prefix),
+    )
+    .await;
 
     let handler = DefaultStateMachineHandler::<MockTypeConfig>::new(
         1,
         0,
         1,
         Arc::new(sm),
-        snapshot_config(temp_dir.path().to_path_buf()),
+        config.clone(),
         MockSnapshotPolicy::new(),
     );
 
-    handler.cleanup_snapshot(2, temp_dir.path()).await.unwrap();
+    handler
+        .cleanup_snapshot(2, temp_dir.path(), &config.snapshots_dir_prefix)
+        .await
+        .unwrap();
 
     //Verify only valid version 1 is deleted
     let remaining = get_dir_names(temp_dir.path()).await;
     debug!(?remaining);
 
     assert!(remaining.contains(&"invalid_format".into()));
-    assert!(remaining.contains(&format!("{SNAPSHOT_DIR_PREFIX}bad-2-2",)));
-    assert!(remaining.contains(&format!("{SNAPSHOT_DIR_PREFIX}1-1",)));
+    assert!(remaining.contains(&format!("{}bad-2-2", &config.snapshots_dir_prefix)));
+    assert!(remaining.contains(&format!("{}1-1", &config.snapshots_dir_prefix)));
 }
 
 /// #Case 1: Reject stale term
@@ -1478,9 +1484,10 @@ async fn create_test_snapshot(
 async fn create_test_files(
     temp_dir: &TempDir,
     ids: &[u64],
+    snapshots_dir_prefix: &str,
 ) {
     for id in ids {
-        let file_name = format!("{SNAPSHOT_DIR_PREFIX}{id}-1.tar.gz");
+        let file_name = format!("{snapshots_dir_prefix}{id}-1.tar.gz",);
         let path = temp_dir.path().join(file_name);
         debug!(?path, "create_test_files");
         let mut file = File::create(&path).await.unwrap();
@@ -1509,91 +1516,91 @@ async fn get_dir_names(path: &Path) -> Vec<String> {
     names
 }
 
-fn mock_node_with_rpc_service(
-    db_path: &str,
-    listen_address: SocketAddr,
-    is_leader: bool,
-    shutdown_signal: watch::Receiver<()>,
-    peers_meta_option: Option<Vec<NodeMeta>>,
-) -> Arc<Node<MockTypeConfig>> {
-    let mut node_config = node_config(db_path);
-    if let Some(peers_meta) = peers_meta_option {
-        node_config.cluster.initial_cluster = peers_meta;
-    }
-
-    // Update listen address with passed one
-    node_config.cluster.listen_address = listen_address;
-    if !is_leader {
-        // Make sure no election happens
-        node_config.raft.election.election_timeout_min = 500000;
-        node_config.raft.election.election_timeout_max = 1000000
-    }
-
-    // Initializing Shutdown Signal
-    let mut replication_handler = MockReplicationCore::new();
-    replication_handler
-        .expect_handle_raft_request_in_batch()
-        .returning(|_, _, _, _| {
-            Ok(AppendResults {
-                commit_quorum_achieved: false,
-                learner_progress: HashMap::new(),
-                peer_updates: HashMap::new(),
-            })
-        });
-    let mut election_handler = MockElectionCore::<MockTypeConfig>::new();
-    election_handler
-        .expect_check_vote_request_is_legal()
-        .returning(|_, _, _, _, _| true);
-    if is_leader {
-        election_handler
-            .expect_broadcast_vote_requests()
-            .returning(|_, _, _, _, _| Ok(()));
-        election_handler
-            .expect_handle_vote_request()
-            .times(1)
-            .returning(move |_, _, _, _| {
-                Ok(StateUpdate {
-                    new_voted_for: Some(VotedFor {
-                        voted_for_id: 1,
-                        voted_for_term: 1,
-                    }),
-                    term_update: Some(2),
-                })
-            });
-    } else {
-        // Make sure node is Follower
-        election_handler.expect_broadcast_vote_requests().returning(|_, _, _, _, _| {
-            Err(Error::Consensus(ConsensusError::Election(
-                ElectionError::HigherTerm(100),
-            )))
-        });
-    }
-    // let state_machine_handler = Arc::new(state_machine_handler);
-    let mut mock_state_machine_handler = MockStateMachineHandler::new();
-    mock_state_machine_handler.expect_apply_snapshot_stream_from_leader().returning(
-        move |_current_term, _stream_request, ack_tx, _| {
-            let ack_tx = ack_tx.clone();
-            tokio::spawn(async move {
-                // Send final ack
-                let final_ack = SnapshotAck {
-                    status: ChunkStatus::Accepted as i32,
-                    seq: u32::MAX,
-                    next_requested: 0,
-                };
-                ack_tx.send(final_ack).await.ok();
-            });
-            Ok(())
-        },
-    );
-
-    MockBuilder::new(shutdown_signal)
-        .with_node_config(node_config)
-        .with_replication_handler(replication_handler)
-        .with_election_handler(election_handler)
-        .with_state_machine_handler(mock_state_machine_handler)
-        .turn_on_election(is_leader)
-        .build_node_with_rpc_server()
-}
+// fn mock_node_with_rpc_service(
+//     db_path: &str,
+//     listen_address: SocketAddr,
+//     is_leader: bool,
+//     shutdown_signal: watch::Receiver<()>,
+//     peers_meta_option: Option<Vec<NodeMeta>>,
+// ) -> Arc<Node<MockTypeConfig>> {
+//     let mut node_config = node_config(db_path);
+//     if let Some(peers_meta) = peers_meta_option {
+//         node_config.cluster.initial_cluster = peers_meta;
+//     }
+
+//     // Update listen address with passed one
+//     node_config.cluster.listen_address = listen_address;
+//     if !is_leader {
+//         // Make sure no election happens
+//         node_config.raft.election.election_timeout_min = 500000;
+//         node_config.raft.election.election_timeout_max = 1000000
+//     }
+
+//     // Initializing Shutdown Signal
+//     let mut replication_handler = MockReplicationCore::new();
+//     replication_handler
+//         .expect_handle_raft_request_in_batch()
+//         .returning(|_, _, _, _| {
+//             Ok(AppendResults {
+//                 commit_quorum_achieved: false,
+//                 learner_progress: HashMap::new(),
+//                 peer_updates: HashMap::new(),
+//             })
+//         });
+//     let mut election_handler = MockElectionCore::<MockTypeConfig>::new();
+//     election_handler
+//         .expect_check_vote_request_is_legal()
+//         .returning(|_, _, _, _, _| true);
+//     if is_leader {
+//         election_handler
+//             .expect_broadcast_vote_requests()
+//             .returning(|_, _, _, _, _| Ok(()));
+//         election_handler
+//             .expect_handle_vote_request()
+//             .times(1)
+//             .returning(move |_, _, _, _| {
+//                 Ok(StateUpdate {
+//                     new_voted_for: Some(VotedFor {
+//                         voted_for_id: 1,
+//                         voted_for_term: 1,
+//                     }),
+//                     term_update: Some(2),
+//                 })
+//             });
+//     } else {
+//         // Make sure node is Follower
+//         election_handler.expect_broadcast_vote_requests().returning(|_, _, _, _, _| {
+//             Err(Error::Consensus(ConsensusError::Election(
+//                 ElectionError::HigherTerm(100),
+//             )))
+//         });
+//     }
+//     // let state_machine_handler = Arc::new(state_machine_handler);
+//     let mut mock_state_machine_handler = MockStateMachineHandler::new();
+//     mock_state_machine_handler.expect_apply_snapshot_stream_from_leader().returning(
+//         move |_current_term, _stream_request, ack_tx, _| {
+//             let ack_tx = ack_tx.clone();
+//             tokio::spawn(async move {
+//                 // Send final ack
+//                 let final_ack = SnapshotAck {
+//                     status: ChunkStatus::Accepted as i32,
+//                     seq: u32::MAX,
+//                     next_requested: 0,
+//                 };
+//                 ack_tx.send(final_ack).await.ok();
+//             });
+//             Ok(())
+//         },
+//     );
+
+//     MockBuilder::new(shutdown_signal)
+//         .with_node_config(node_config)
+//         .with_replication_handler(replication_handler)
+//         .with_election_handler(election_handler)
+//         .with_state_machine_handler(mock_state_machine_handler)
+//         .turn_on_election(is_leader)
+//         .build_node_with_rpc_server()
+// }
 
 // Update test_load_snapshot_data_case1_single_file_single_chunk
 #[tokio::test]
@@ -1899,7 +1906,7 @@ async fn test_apply_snapshot_stream_from_leader_decompresses_before_apply() {
         chunk_checksum: Bytes::from(chunk_checksum),
     };
 
-    let streaming_request = crate_test_snapshot_stream(vec![chunk]);
+    let streaming_request = create_test_snapshot_stream(vec![chunk]);
     let (ack_tx, mut ack_rx) = mpsc::channel::<SnapshotAck>(1);
 
     let handler_task = tokio::spawn({
diff --git a/src/core/state_machine_handler/mod.rs b/d-engine-core/src/state_machine_handler/mod.rs
similarity index 89%
rename from src/core/state_machine_handler/mod.rs
rename to d-engine-core/src/state_machine_handler/mod.rs
index 5eda62fb..6b953ed6 100644
--- a/src/core/state_machine_handler/mod.rs
+++ b/d-engine-core/src/state_machine_handler/mod.rs
@@ -36,35 +36,35 @@ mod snapshot_assembler;
 mod snapshot_guard;
 mod snapshot_policy;
 
-pub(crate) use default_state_machine_handler::*;
+pub use default_state_machine_handler::*;
+pub use snapshot_policy::*;
+
 pub(crate) use snapshot_assembler::*;
 pub(crate) use snapshot_guard::*;
-pub(crate) use snapshot_policy::*;
 
 #[cfg(test)]
 mod default_state_machine_handler_test;
 #[cfg(test)]
 mod snapshot_assembler_test;
 
-use std::sync::Arc;
-
 use futures::stream::BoxStream;
-#[cfg(test)]
+#[cfg(any(test, feature = "test-utils"))]
 use mockall::automock;
+use std::sync::Arc;
 use tonic::async_trait;
 
 use super::NewCommitData;
-use crate::alias::ROF;
-use crate::proto::client::ClientResult;
-use crate::proto::common::LogId;
-use crate::proto::storage::PurgeLogRequest;
-use crate::proto::storage::PurgeLogResponse;
-use crate::proto::storage::SnapshotChunk;
-use crate::proto::storage::SnapshotMetadata;
 use crate::Result;
 use crate::TypeConfig;
-
-#[cfg_attr(test, automock)]
+use crate::alias::ROF;
+use d_engine_proto::client::ClientResult;
+use d_engine_proto::common::LogId;
+use d_engine_proto::server::storage::PurgeLogRequest;
+use d_engine_proto::server::storage::PurgeLogResponse;
+use d_engine_proto::server::storage::SnapshotChunk;
+use d_engine_proto::server::storage::SnapshotMetadata;
+
+#[cfg_attr(any(test, feature = "test-utils"), automock)]
 #[async_trait]
 pub trait StateMachineHandler<T>: Send + Sync + 'static
 where
@@ -81,7 +81,7 @@ where
     /// Applies a batch of committed log entries to the state machine
     async fn apply_chunk(
         &self,
-        chunk: Vec<crate::proto::common::Entry>,
+        chunk: Vec<d_engine_proto::common::Entry>,
     ) -> Result<()>;
 
     /// Reads values from the state machine for given keys
@@ -97,7 +97,7 @@ where
         &self,
         current_term: u64,
         stream: Box<tonic::Streaming<SnapshotChunk>>,
-        ack_tx: tokio::sync::mpsc::Sender<crate::proto::storage::SnapshotAck>,
+        ack_tx: tokio::sync::mpsc::Sender<d_engine_proto::server::storage::SnapshotAck>,
         config: &crate::SnapshotConfig,
     ) -> Result<()>;
 
@@ -125,6 +125,7 @@ where
         &self,
         before_version: u64,
         snapshot_dir: &std::path::Path,
+        snapshot_dir_prefix: &str,
     ) -> crate::Result<()>;
 
     /// Validates if a log purge request from leader is authorized
diff --git a/src/core/state_machine_handler/snapshot_assembler.rs b/d-engine-core/src/state_machine_handler/snapshot_assembler.rs
similarity index 99%
rename from src/core/state_machine_handler/snapshot_assembler.rs
rename to d-engine-core/src/state_machine_handler/snapshot_assembler.rs
index 9a376550..c1421ae0 100644
--- a/src/core/state_machine_handler/snapshot_assembler.rs
+++ b/d-engine-core/src/state_machine_handler/snapshot_assembler.rs
@@ -1,7 +1,7 @@
 use std::path::PathBuf;
+use std::sync::Arc;
 use std::sync::atomic::AtomicU32;
 use std::sync::atomic::Ordering;
-use std::sync::Arc;
 use std::time::SystemTime;
 use std::time::UNIX_EPOCH;
 
@@ -12,12 +12,12 @@ use tracing::debug;
 use tracing::trace;
 use tracing::warn;
 
-use crate::file_io::create_parent_dir_if_not_exist;
-use crate::proto::storage::SnapshotMetadata;
 use crate::Result;
 use crate::SnapshotError;
 use crate::SnapshotPathManager;
 use crate::StorageError;
+use crate::file_io::create_parent_dir_if_not_exist;
+use d_engine_proto::server::storage::SnapshotMetadata;
 
 pub(crate) struct SnapshotAssembler {
     temp_file: File,
diff --git a/src/core/state_machine_handler/snapshot_assembler_test.rs b/d-engine-core/src/state_machine_handler/snapshot_assembler_test.rs
similarity index 98%
rename from src/core/state_machine_handler/snapshot_assembler_test.rs
rename to d-engine-core/src/state_machine_handler/snapshot_assembler_test.rs
index 5a28f056..605884fb 100644
--- a/src/core/state_machine_handler/snapshot_assembler_test.rs
+++ b/d-engine-core/src/state_machine_handler/snapshot_assembler_test.rs
@@ -5,10 +5,10 @@ use tempfile::tempdir;
 use tokio::fs::read;
 use tracing_test::traced_test;
 
-use crate::proto::common::LogId;
-use crate::proto::storage::SnapshotMetadata;
 use crate::SnapshotAssembler;
 use crate::SnapshotPathManager;
+use d_engine_proto::common::LogId;
+use d_engine_proto::server::storage::SnapshotMetadata;
 
 #[tokio::test]
 #[traced_test]
diff --git a/src/core/state_machine_handler/snapshot_guard.rs b/d-engine-core/src/state_machine_handler/snapshot_guard.rs
similarity index 100%
rename from src/core/state_machine_handler/snapshot_guard.rs
rename to d-engine-core/src/state_machine_handler/snapshot_guard.rs
diff --git a/src/core/state_machine_handler/snapshot_policy/composite.rs b/d-engine-core/src/state_machine_handler/snapshot_policy/composite.rs
similarity index 100%
rename from src/core/state_machine_handler/snapshot_policy/composite.rs
rename to d-engine-core/src/state_machine_handler/snapshot_policy/composite.rs
diff --git a/src/core/state_machine_handler/snapshot_policy/composite_test.rs b/d-engine-core/src/state_machine_handler/snapshot_policy/composite_test.rs
similarity index 93%
rename from src/core/state_machine_handler/snapshot_policy/composite_test.rs
rename to d-engine-core/src/state_machine_handler/snapshot_policy/composite_test.rs
index cae7ba09..f650f4a9 100644
--- a/src/core/state_machine_handler/snapshot_policy/composite_test.rs
+++ b/d-engine-core/src/state_machine_handler/snapshot_policy/composite_test.rs
@@ -3,19 +3,16 @@ use std::time::Duration;
 use tracing_test::traced_test;
 
 use super::*;
-use crate::core::state_machine_handler::snapshot_policy::SnapshotContext;
-use crate::core::state_machine_handler::snapshot_policy::SnapshotPolicy;
-use crate::proto::common::LogId;
-use crate::FOLLOWER;
-use crate::LEADER;
-
-const LEADER_ROLE: i32 = LEADER;
-const FOLLOWER_ROLE: i32 = FOLLOWER;
+use crate::state_machine_handler::snapshot_policy::SnapshotContext;
+use crate::state_machine_handler::snapshot_policy::SnapshotPolicy;
+use d_engine_proto::common::LogId;
+use d_engine_proto::common::NodeRole::Follower;
+use d_engine_proto::common::NodeRole::Leader;
 
 /// Creates a leader context for testing
 fn leader_ctx(last_applied_index: u64) -> SnapshotContext {
     SnapshotContext {
-        role: LEADER_ROLE,
+        role: Leader.into(),
         last_included: LogId { term: 1, index: 0 },
         last_applied: LogId {
             term: 1,
@@ -28,7 +25,7 @@ fn leader_ctx(last_applied_index: u64) -> SnapshotContext {
 /// Creates a follower context for testing
 fn follower_ctx(last_applied_index: u64) -> SnapshotContext {
     SnapshotContext {
-        role: FOLLOWER_ROLE,
+        role: Follower.into(),
         last_included: LogId { term: 1, index: 0 },
         last_applied: LogId {
             term: 1,
diff --git a/src/core/state_machine_handler/snapshot_policy/log_size.rs b/d-engine-core/src/state_machine_handler/snapshot_policy/log_size.rs
similarity index 99%
rename from src/core/state_machine_handler/snapshot_policy/log_size.rs
rename to d-engine-core/src/state_machine_handler/snapshot_policy/log_size.rs
index 08bb0a4a..bbccc16c 100644
--- a/src/core/state_machine_handler/snapshot_policy/log_size.rs
+++ b/d-engine-core/src/state_machine_handler/snapshot_policy/log_size.rs
@@ -68,7 +68,7 @@ impl SnapshotPolicy for LogSizePolicy {
 }
 
 impl LogSizePolicy {
-    pub(crate) fn new(
+    pub fn new(
         threshold: u64,
         cooldown: Duration,
     ) -> Self {
diff --git a/src/core/state_machine_handler/snapshot_policy/log_size_test.rs b/d-engine-core/src/state_machine_handler/snapshot_policy/log_size_test.rs
similarity index 84%
rename from src/core/state_machine_handler/snapshot_policy/log_size_test.rs
rename to d-engine-core/src/state_machine_handler/snapshot_policy/log_size_test.rs
index 068602c4..c448752f 100644
--- a/src/core/state_machine_handler/snapshot_policy/log_size_test.rs
+++ b/d-engine-core/src/state_machine_handler/snapshot_policy/log_size_test.rs
@@ -3,11 +3,11 @@ use std::time::Duration;
 use std::time::Instant;
 
 use super::SnapshotContext;
-use crate::proto::common::LogId;
 use crate::LogSizePolicy;
 use crate::SnapshotPolicy;
-use crate::FOLLOWER;
-use crate::LEADER;
+use d_engine_proto::common::LogId;
+use d_engine_proto::common::NodeRole::Follower;
+use d_engine_proto::common::NodeRole::Leader;
 
 // Test context builder for better test readability
 fn test_context(
@@ -32,28 +32,28 @@ fn test_context(
 #[test]
 fn triggers_when_log_size_exceeds_threshold() {
     let policy = LogSizePolicy::new(1000, Duration::from_secs(1));
-    let ctx = test_context(1500, 500, LEADER);
+    let ctx = test_context(1500, 500, Leader.into());
     assert!(policy.should_trigger(&ctx));
 }
 
 #[test]
 fn does_not_trigger_below_threshold() {
     let policy = LogSizePolicy::new(1000, Duration::from_secs(1));
-    let ctx = test_context(1499, 500, LEADER);
+    let ctx = test_context(1499, 500, Leader.into());
     assert!(!policy.should_trigger(&ctx));
 }
 
 #[test]
 fn triggers_at_exact_threshold() {
     let policy = LogSizePolicy::new(1000, Duration::from_secs(1));
-    let ctx = test_context(1500, 500, LEADER);
+    let ctx = test_context(1500, 500, Leader.into());
     assert!(policy.should_trigger(&ctx));
 }
 
 #[test]
 fn respects_cooldown_period() {
     let policy = LogSizePolicy::new(100, Duration::from_secs(1));
-    let mut ctx = test_context(200, 100, LEADER);
+    let mut ctx = test_context(200, 100, Leader.into());
 
     // Initial check should trigger
     assert!(policy.should_trigger(&ctx));
@@ -66,7 +66,7 @@ fn respects_cooldown_period() {
 #[test]
 fn resets_after_cooldown_period() {
     let policy = LogSizePolicy::new(100, Duration::from_millis(100));
-    let ctx = test_context(200, 100, LEADER);
+    let ctx = test_context(200, 100, Leader.into());
 
     // First trigger
     assert!(policy.should_trigger(&ctx));
@@ -79,7 +79,7 @@ fn resets_after_cooldown_period() {
 #[test]
 fn handles_concurrent_checks_with_cooldown() {
     let policy = Arc::new(LogSizePolicy::new(100, Duration::from_secs(1)));
-    let ctx = test_context(200, 100, LEADER);
+    let ctx = test_context(200, 100, Leader.into());
 
     let handles: Vec<_> = (0..10)
         .map(|_| {
@@ -96,14 +96,14 @@ fn handles_concurrent_checks_with_cooldown() {
 #[test]
 fn non_leader_never_triggers() {
     let policy = LogSizePolicy::new(100, Duration::ZERO);
-    let ctx = test_context(200, 100, FOLLOWER);
+    let ctx = test_context(200, 100, Follower.into());
     assert!(!policy.should_trigger(&ctx));
 }
 
 #[test]
 fn dynamic_threshold_adjustment() {
     let policy = LogSizePolicy::new(1000, Duration::from_secs(1));
-    let ctx = test_context(1200, 500, LEADER);
+    let ctx = test_context(1200, 500, Leader.into());
 
     // Initial threshold not met
     assert!(!policy.should_trigger(&ctx));
@@ -126,7 +126,7 @@ fn handles_term_regression() {
             term: 3,
         }, // Higher than current term
         current_term: 2,
-        role: LEADER,
+        role: Leader.into(),
     };
 
     assert!(!policy.should_trigger(&ctx));
@@ -135,7 +135,7 @@ fn handles_term_regression() {
 #[test]
 fn high_frequency_performance() {
     let policy = LogSizePolicy::new(1000, Duration::from_millis(100));
-    let ctx = test_context(1500, 500, LEADER);
+    let ctx = test_context(1500, 500, Leader.into());
 
     let start = Instant::now();
     let mut trigger_count = 0;
diff --git a/src/core/state_machine_handler/snapshot_policy/mod.rs b/d-engine-core/src/state_machine_handler/snapshot_policy/mod.rs
similarity index 85%
rename from src/core/state_machine_handler/snapshot_policy/mod.rs
rename to d-engine-core/src/state_machine_handler/snapshot_policy/mod.rs
index 6c918094..a733b890 100644
--- a/src/core/state_machine_handler/snapshot_policy/mod.rs
+++ b/d-engine-core/src/state_machine_handler/snapshot_policy/mod.rs
@@ -6,12 +6,12 @@ mod log_size;
 mod time_based;
 #[allow(unused)]
 pub(crate) use composite::*;
-pub(crate) use log_size::*;
+pub use log_size::*;
 #[allow(unused)]
 pub(crate) use time_based::*;
 
 use crate::cluster::is_leader;
-use crate::proto::common::LogId;
+use d_engine_proto::common::LogId;
 
 #[cfg(test)]
 mod composite_test;
@@ -20,10 +20,10 @@ mod log_size_test;
 #[cfg(test)]
 mod time_based_test;
 
-#[cfg(test)]
+#[cfg(any(test, feature = "test-utils"))]
 use mockall::automock;
 
-#[cfg_attr(test, automock)]
+#[cfg_attr(any(test, feature = "test-utils"), automock)]
 pub trait SnapshotPolicy: Send + Sync {
     fn should_trigger(
         &self,
diff --git a/src/core/state_machine_handler/snapshot_policy/time_based.rs b/d-engine-core/src/state_machine_handler/snapshot_policy/time_based.rs
similarity index 100%
rename from src/core/state_machine_handler/snapshot_policy/time_based.rs
rename to d-engine-core/src/state_machine_handler/snapshot_policy/time_based.rs
diff --git a/src/core/state_machine_handler/snapshot_policy/time_based_test.rs b/d-engine-core/src/state_machine_handler/snapshot_policy/time_based_test.rs
similarity index 85%
rename from src/core/state_machine_handler/snapshot_policy/time_based_test.rs
rename to d-engine-core/src/state_machine_handler/snapshot_policy/time_based_test.rs
index fe2b7690..7418c2e7 100644
--- a/src/core/state_machine_handler/snapshot_policy/time_based_test.rs
+++ b/d-engine-core/src/state_machine_handler/snapshot_policy/time_based_test.rs
@@ -4,10 +4,10 @@ use tokio::time;
 use tracing_test::traced_test;
 
 use super::*;
-use crate::core::state_machine_handler::snapshot_policy::SnapshotContext;
-use crate::core::state_machine_handler::snapshot_policy::SnapshotPolicy;
-use crate::proto::common::LogId;
-use crate::LEADER;
+use crate::state_machine_handler::snapshot_policy::SnapshotContext;
+use crate::state_machine_handler::snapshot_policy::SnapshotPolicy;
+use d_engine_proto::common::LogId;
+use d_engine_proto::common::NodeRole::Leader;
 
 #[tokio::test]
 #[traced_test]
@@ -19,7 +19,7 @@ async fn test_should_trigger_after_interval() {
 
     // Create context (leader)
     let ctx = SnapshotContext {
-        role: LEADER, // Assuming LEADER is defined elsewhere
+        role: Leader.into(), // Assuming Leader is defined elsewhere
         last_included: LogId { term: 1, index: 1 },
         last_applied: LogId { term: 1, index: 10 },
         current_term: 1,
@@ -45,7 +45,7 @@ async fn test_should_not_trigger_before_interval() {
 
     // Create context (leader)
     let ctx = SnapshotContext {
-        role: LEADER,
+        role: Leader.into(),
         last_included: LogId { term: 1, index: 1 },
         last_applied: LogId { term: 1, index: 10 },
         current_term: 1,
@@ -67,7 +67,7 @@ async fn test_reset_timer_works() {
     policy.reset_timer();
 
     let ctx = SnapshotContext {
-        role: LEADER,
+        role: Leader.into(),
         last_included: LogId { term: 1, index: 1 },
         last_applied: LogId { term: 1, index: 10 },
         current_term: 1,
diff --git a/src/core/state_machine_handler/snapshot_stream_processor.rs b/d-engine-core/src/state_machine_handler/snapshot_stream_processor.rs
similarity index 100%
rename from src/core/state_machine_handler/snapshot_stream_processor.rs
rename to d-engine-core/src/state_machine_handler/snapshot_stream_processor.rs
diff --git a/d-engine-core/src/storage/mod.rs b/d-engine-core/src/storage/mod.rs
new file mode 100644
index 00000000..bbec6efa
--- /dev/null
+++ b/d-engine-core/src/storage/mod.rs
@@ -0,0 +1,15 @@
+mod raft_log;
+mod snapshot_path_manager;
+mod state_machine;
+mod storage_engine;
+
+pub(crate) use snapshot_path_manager::*;
+pub use state_machine::*;
+pub use storage_engine::*;
+
+#[doc(hidden)]
+pub use raft_log::*;
+#[doc(hidden)]
+pub mod state_machine_test;
+#[doc(hidden)]
+pub mod storage_engine_test;
diff --git a/d-engine-core/src/storage/raft_log.rs b/d-engine-core/src/storage/raft_log.rs
new file mode 100644
index 00000000..012407f7
--- /dev/null
+++ b/d-engine-core/src/storage/raft_log.rs
@@ -0,0 +1,450 @@
+//! RaftLog trait with explicit safety contracts and documentation
+//!
+//! This trait defines the interface for Raft log storage with comprehensive
+//! safety guarantees. Implementers MUST adhere to all documented invariants
+//! to maintain Raft consensus protocol correctness.
+//!
+//! Key Safety Properties (from Raft paper):
+//! 1. Log Matching: If two logs contain an entry with same index and term,
+//!    then logs are identical in all preceding entries
+//! 2. Leader Append-Only: Leaders never overwrite or delete entries
+//! 3. State Machine Safety: If a server has applied a log entry at a given
+//!    index, no other server will ever apply a different log entry for that index
+
+use crate::Result;
+use d_engine_proto::common::Entry;
+use d_engine_proto::common::LogId;
+
+#[cfg(any(test, feature = "test-utils"))]
+use mockall::automock;
+use std::ops::RangeInclusive;
+use tonic::async_trait;
+
+#[cfg_attr(any(test, feature = "test-utils"), automock)]
+#[async_trait]
+pub trait RaftLog: Send + Sync + 'static {
+    // =========================================================================
+    // READ OPERATIONS (Lock-free, no side effects)
+    // =========================================================================
+
+    /// Retrieves a log entry by index.
+    ///
+    /// # Returns
+    /// - `Ok(Some(entry))` if entry exists
+    /// - `Ok(None)` if index is out of range
+    /// - `Err(_)` only for unrecoverable storage errors
+    ///
+    /// # Safety Invariants
+    /// - MUST be thread-safe and lock-free for maximum performance
+    /// - MUST NOT modify any state
+    /// - MUST return consistent data within a single term
+    fn entry(
+        &self,
+        index: u64,
+    ) -> Result<Option<Entry>>;
+
+    /// Returns the smallest log index (inclusive).
+    ///
+    /// # Returns
+    /// - `0` if log is empty
+    /// - First index otherwise (typically 1 after initialization)
+    ///
+    /// # Safety Invariants
+    /// - MUST be monotonically non-decreasing (can only increase via purge)
+    /// - MUST be <= last_entry_id()
+    fn first_entry_id(&self) -> u64;
+
+    /// Returns the largest log index (inclusive).
+    ///
+    /// # Returns
+    /// - `0` if log is empty
+    /// - Last index otherwise
+    ///
+    /// # Safety Invariants
+    /// - MUST be monotonically non-decreasing during normal operation
+    /// - Can decrease only during conflict resolution (filter_out_conflicts_and_append)
+    /// - MUST be >= first_entry_id()
+    fn last_entry_id(&self) -> u64;
+
+    /// Returns the LogId (term + index) of the last entry.
+    ///
+    /// # Returns
+    /// - `None` if log is empty
+    /// - `Some(LogId)` otherwise
+    ///
+    /// # Safety Invariants
+    /// - MUST match last_entry().map(|e| LogId { term: e.term, index: e.index })
+    /// - Critical for leader election and log matching
+    fn last_log_id(&self) -> Option<LogId>;
+
+    /// Returns the last log entry.
+    ///
+    /// # Safety Invariants
+    /// - MUST be equivalent to entry(last_entry_id())
+    /// - Performance optimization for common access pattern
+    fn last_entry(&self) -> Option<Entry>;
+
+    /// Checks if log is empty.
+    ///
+    /// # Safety Invariants
+    /// - MUST be equivalent to (first_entry_id() == 0)
+    fn is_empty(&self) -> bool;
+
+    /// Returns the term of a specific entry.
+    ///
+    /// # Safety Invariants
+    /// - MUST be equivalent to entry(entry_id).map(|e| e.term)
+    /// - Critical for AppendEntries RPC consistency checks
+    fn entry_term(
+        &self,
+        entry_id: u64,
+    ) -> Option<u64>;
+    /// Finds the first index belonging to a specific term.
+    ///
+    /// # Returns
+    /// - `None` if no entry with this term exists
+    /// - `Some(index)` of the first entry with matching term
+    ///
+    /// # Safety Invariants
+    /// - MUST scan forward from first_entry_id()
+    /// - Result MUST be <= last_index_for_term(term)
+    /// - Critical for calculating commit index
+    fn first_index_for_term(
+        &self,
+        term: u64,
+    ) -> Option<u64>;
+
+    /// Finds the last index belonging to a specific term.
+    ///
+    /// # Returns
+    /// - `None` if no entry with this term exists
+    /// - `Some(index)` of the last entry with matching term
+    ///
+    /// # Safety Invariants
+    /// - MUST scan backward from last_entry_id()
+    /// - Result MUST be >= first_index_for_term(term)
+    /// - Critical for leader election and log compaction
+    fn last_index_for_term(
+        &self,
+        term: u64,
+    ) -> Option<u64>;
+
+    /// Retrieves a contiguous range of log entries.
+    ///
+    /// # Arguments
+    /// - `range`: Inclusive range [start, end]
+    ///
+    /// # Returns
+    /// - `Ok(Vec<Entry>)` with all entries in range
+    /// - Empty vec if range is out of bounds
+    ///
+    /// # Safety Invariants
+    /// - Returned entries MUST be ordered by index (ascending)
+    /// - MUST include all entries in range without gaps
+    /// - Critical for AppendEntries RPC replication
+    fn get_entries_range(
+        &self,
+        range: RangeInclusive<u64>,
+    ) -> Result<Vec<Entry>>;
+
+    // =========================================================================
+    // INDEX ALLOCATION (Thread-safe, atomic)
+    // =========================================================================
+
+    /// Pre-allocates the next log index atomically.
+    ///
+    /// # Returns
+    /// - Next available index
+    ///
+    /// # Safety Invariants
+    /// - MUST be thread-safe (atomic increment)
+    /// - MUST return unique, monotonically increasing values
+    /// - Each call MUST return a different value across all threads
+    /// - Used by leader to assign indexes to client proposals
+    fn pre_allocate_raft_logs_next_index(&self) -> u64;
+
+    /// Pre-allocates a contiguous range of log indices atomically.
+    ///
+    /// # Arguments
+    /// - `count`: Number of indices to allocate
+    ///
+    /// # Returns
+    /// - Inclusive range [start, end] where (end - start + 1) == count
+    /// - Empty range (u64::MAX..=u64::MAX) if count == 0
+    ///
+    /// # Safety Invariants
+    /// - MUST be atomic across all threads
+    /// - MUST NOT return overlapping ranges
+    /// - MUST prevent overflow (panic if allocation would exceed u64::MAX)
+    /// - Used for batch proposal optimization
+    fn pre_allocate_id_range(
+        &self,
+        count: u64,
+    ) -> RangeInclusive<u64>;
+
+    // =========================================================================
+    // WRITE OPERATIONS (CRITICAL: Durability and Atomicity Required)
+    // =========================================================================
+
+    /// Appends new entries to the log.
+    ///
+    /// # Arguments
+    /// - `entries`: New log entries to append (must be ordered by index)
+    ///
+    /// # Durability Contract
+    /// **CRITICAL**: Implementers MUST choose one of these strategies:
+    ///
+    /// 1. **Disk-First (Safest, Recommended for Leaders)**:
+    ///    - Persist entries to durable storage BEFORE updating in-memory state
+    ///    - Call fsync/flush before returning Ok(())
+    ///    - Ensures entries survive crashes immediately
+    ///    - Example: BufferedRaftLog with PersistenceStrategy::DiskFirst
+    ///
+    /// 2. **Memory-First (Performance-optimized, Acceptable for Followers)**:
+    ///    - Update in-memory state first
+    ///    - Enqueue entries for asynchronous durability
+    ///    - MUST guarantee eventual durability via background flush
+    ///    - MUST call flush() before acknowledging commits
+    ///    - Example: BufferedRaftLog with PersistenceStrategy::MemFirst
+    ///    - WARNING: Leader MUST wait_durable() before responding to AppendEntries RPCs
+    ///
+    /// # Safety Invariants
+    /// - Entries MUST have strictly increasing indices (no gaps)
+    /// - Entries MUST NOT conflict with existing entries (use filter_out_conflicts_and_append for that)
+    /// - After successful return, entries MUST be retrievable via entry()
+    /// - MUST update last_entry_id() atomically
+    /// - MUST update term indexes (first/last_index_for_term) atomically
+    ///
+    /// # Raft Protocol Integration
+    /// - Leaders using MemFirst MUST call wait_durable(index) before:
+    ///   * Responding success to AppendEntries RPC
+    ///   * Advancing commit index
+    /// - Followers can use MemFirst safely because leader durability guarantees safety
+    ///
+    /// # Failure Semantics
+    /// - On error, implementer MAY roll back partial writes
+    /// - Caller MUST retry or initiate crash recovery
+    async fn append_entries(
+        &self,
+        entries: Vec<Entry>,
+    ) -> Result<()>;
+
+    /// Waits for a specific log index to become durable.
+    ///
+    /// # Arguments
+    /// - `index`: Log index to wait for
+    ///
+    /// # Returns
+    /// - `Ok(())` when index is guaranteed durable
+    /// - `Err(_)` if waiting failed (channel closed, timeout, etc.)
+    ///
+    /// # Usage Pattern
+    /// ```rust,ignore
+    /// // Leader with MemFirst strategy
+    /// raft_log.append_entries(new_entries).await?;
+    /// raft_log.wait_durable(max_index).await?;  // MUST wait before RPC response
+    /// respond_to_client(Ok(()));
+    /// ```
+    ///
+    /// # Safety Invariants
+    /// - MUST NOT return until flush() for this index completes successfully
+    /// - If implementation doesn't support async durability, return Ok(()) immediately
+    /// - Critical for MemFirst strategy correctness
+    async fn wait_durable(
+        &self,
+        index: u64,
+    ) -> Result<()> {
+        // Default implementation for DiskFirst: no-op (already durable)
+        let _ = index;
+        Ok(())
+    }
+
+    /// Alias for append_entries (for backward compatibility).
+    ///
+    /// # Safety Invariants
+    /// - MUST have identical semantics to append_entries()
+    async fn insert_batch(
+        &self,
+        logs: Vec<Entry>,
+    ) -> Result<()> {
+        self.append_entries(logs).await
+    }
+
+    /// Resolves log conflicts and appends new entries atomically.
+    ///
+    /// This is the core of Raft's log replication safety. Implements the
+    /// AppendEntries RPC log consistency check and conflict resolution.
+    ///
+    /// # Arguments
+    /// - `prev_log_index`: Index of entry immediately preceding new entries
+    /// - `prev_log_term`: Term of entry at prev_log_index
+    /// - `new_entries`: New entries to append
+    ///
+    /// # Algorithm (from Raft paper §5.3)
+    /// 1. **Virtual Log Check**: If prev_log_index == 0 && prev_log_term == 0:
+    ///    - Clear entire log (snapshot installation)
+    ///    - Append all new entries
+    /// 2. **Consistency Check**: Verify entry at prev_log_index has term == prev_log_term
+    ///    - If mismatch, return current last_log_id (reject)
+    /// 3. **Conflict Resolution**: If existing entries conflict with new ones:
+    ///    - Delete all entries from prev_log_index+1 onwards
+    ///    - Append new entries
+    /// 4. **Optimization**: If prev_log_index >= last_entry_id:
+    ///    - No conflicts, directly append
+    ///
+    /// # Returns
+    /// - `Ok(Some(new_last_log_id))` on success (entries appended)
+    /// - `Ok(None)` or `Ok(Some(current_last_log_id))` on consistency failure (rejected)
+    /// - `Err(_)` on storage failure
+    ///
+    /// # Safety Invariants (CRITICAL)
+    /// - Truncation + Append MUST be atomic (no partial state visible)
+    /// - If crash occurs mid-operation, log MUST be in consistent state after recovery
+    /// - MUST NOT violate Log Matching Property (Raft invariant)
+    /// - MUST update term indexes atomically with log changes
+    /// - After success, all entries from first_entry_id to new last index MUST be contiguous
+    ///
+    /// # Recommended Implementation Pattern
+    /// ```rust,ignore
+    /// async fn filter_out_conflicts_and_append(...) -> Result<Option<LogId>> {
+    ///     // 1. Validate consistency (read-only)
+    ///     // 2. Begin transaction/write batch
+    ///     // 3. Truncate conflicting entries
+    ///     // 4. Append new entries
+    ///     // 5. Commit transaction/flush write batch
+    ///     // 6. Update in-memory indexes atomically
+    /// }
+    /// ```
+    async fn filter_out_conflicts_and_append(
+        &self,
+        prev_log_index: u64,
+        prev_log_term: u64,
+        new_entries: Vec<Entry>,
+    ) -> Result<Option<LogId>>;
+
+    /// Calculates the majority-matched index for commit advancement.
+    ///
+    /// # Arguments
+    /// - `current_term`: Leader's current term
+    /// - `commit_index`: Current committed index
+    /// - `matched_ids`: Follower match indexes (leader's last index added automatically)
+    ///
+    /// # Algorithm (Raft paper §5.3, §5.4)
+    /// 1. Sort all matched indexes (including leader's) in descending order
+    /// 2. Find median index (majority quorum)
+    /// 3. Verify conditions:
+    ///    - majority_index >= commit_index
+    ///    - entry at majority_index has term == current_term
+    ///
+    /// # Returns
+    /// - `Some(new_commit_index)` if conditions met
+    /// - `None` if no advancement possible
+    ///
+    /// # Safety Invariants
+    /// - MUST verify term matches current_term (prevents committing entries from old terms)
+    /// - MUST NOT decrease commit index
+    /// - Critical for State Machine Safety property
+    fn calculate_majority_matched_index(
+        &self,
+        current_term: u64,
+        commit_index: u64,
+        matched_ids: Vec<u64>,
+    ) -> Option<u64>;
+
+    /// Purges committed log entries up to cutoff_index (log compaction).
+    ///
+    /// # Arguments
+    /// - `cutoff_index`: LogId of last entry to purge (inclusive)
+    ///
+    /// # Safety Invariants (CRITICAL)
+    /// - MUST only be called after entries applied to state machine
+    /// - MUST NOT purge entries beyond last_applied_index
+    /// - After purge, first_entry_id() MUST be cutoff_index.index + 1
+    /// - MUST be atomic (no partial purge visible)
+    /// - MUST NOT cause gaps in remaining log
+    /// - MUST update term indexes correctly
+    ///
+    /// # Durability Contract
+    /// - Changes MUST be durable before returning Ok(())
+    /// - On crash, either old or new state MUST be consistent
+    ///
+    /// # Recommended Implementation
+    /// - Coordinate with snapshot mechanism
+    /// - Ensure snapshot covers purged range
+    async fn purge_logs_up_to(
+        &self,
+        cutoff_index: LogId,
+    ) -> Result<()>;
+
+    /// Forces all pending writes to durable storage.
+    ///
+    /// # Durability Contract
+    /// - After successful return, ALL previously written entries MUST survive crashes
+    /// - MUST call fsync/fdatasync or equivalent
+    /// - MUST block until durability guaranteed
+    ///
+    /// # When to Call
+    /// - Before acknowledging commits to clients
+    /// - Before voting in elections
+    /// - Before responding to AppendEntries RPCs
+    /// - Before taking snapshots
+    ///
+    /// # Performance Note
+    /// - This is expensive; batch writes when possible
+    /// - Consider group commit optimization
+    async fn flush(&self) -> Result<()>;
+
+    /// Resets the entire log storage (destructive operation).
+    ///
+    /// # Safety Invariants
+    /// - MUST clear all log entries
+    /// - MUST clear all metadata
+    /// - MUST reset first_entry_id() and last_entry_id() to 0
+    /// - MUST clear term indexes
+    /// - MUST be atomic (no partial state visible)
+    /// - MUST NOT be called during normal operation (only during initialization/recovery)
+    ///
+    /// # Durability Contract
+    /// - Changes MUST be durable before returning Ok(())
+    async fn reset(&self) -> Result<()>;
+
+    // =========================================================================
+    // PERSISTENT STATE (Raft Paper §5.2)
+    // =========================================================================
+
+    /// Loads persistent state (currentTerm, votedFor).
+    ///
+    /// # Returns
+    /// - `Ok(Some(HardState))` if state exists
+    /// - `Ok(None)` if no state persisted yet (first boot)
+    /// - `Err(_)` on storage failure
+    ///
+    /// # Safety Invariants
+    /// - MUST return most recently saved state
+    /// - MUST survive crashes (durably persisted)
+    fn load_hard_state(&self) -> Result<Option<crate::HardState>>;
+
+    /// Saves persistent state (currentTerm, votedFor).
+    ///
+    /// # Arguments
+    /// - `hard_state`: Current term and vote information
+    ///
+    /// # Durability Contract (CRITICAL)
+    /// - MUST be durable BEFORE returning Ok(())
+    /// - MUST call fsync/flush before returning
+    /// - On crash after return, state MUST be retrievable via load_hard_state()
+    ///
+    /// # Safety Invariants
+    /// - Violating durability breaks election safety (vote splitting)
+    /// - MUST be atomic with respect to load_hard_state()
+    /// - Term MUST NOT decrease (except during reset)
+    ///
+    /// # When to Call
+    /// - Before voting for a candidate
+    /// - When becoming candidate (incrementing term)
+    /// - When discovering higher term
+    fn save_hard_state(
+        &self,
+        hard_state: &crate::HardState,
+    ) -> Result<()>;
+}
diff --git a/src/storage/snapshot_path_manager.rs b/d-engine-core/src/storage/snapshot_path_manager.rs
similarity index 99%
rename from src/storage/snapshot_path_manager.rs
rename to d-engine-core/src/storage/snapshot_path_manager.rs
index c525a4e6..624ef1f6 100644
--- a/src/storage/snapshot_path_manager.rs
+++ b/d-engine-core/src/storage/snapshot_path_manager.rs
@@ -1,6 +1,6 @@
 use std::path::PathBuf;
 
-use crate::proto::common::LogId;
+use d_engine_proto::common::LogId;
 
 /// Centralized manager for all snapshot-related path generation and naming conventions.
 ///
diff --git a/src/storage/state_machine.rs b/d-engine-core/src/storage/state_machine.rs
similarity index 88%
rename from src/storage/state_machine.rs
rename to d-engine-core/src/storage/state_machine.rs
index 020a051a..40329540 100644
--- a/src/storage/state_machine.rs
+++ b/d-engine-core/src/storage/state_machine.rs
@@ -1,17 +1,17 @@
-#![doc = include_str!("../docs/server_guide/customize-state-machine.md")]
+#![doc = include_str!("../../../d-engine-docs/src/docs/server_guide/customize-state-machine.md")]
 
 use bytes::Bytes;
-#[cfg(test)]
+
+#[cfg(any(test, feature = "test-utils"))]
 use mockall::automock;
-use tonic::async_trait;
 
-use crate::proto::common::Entry;
-use crate::proto::common::LogId;
-use crate::proto::storage::SnapshotMetadata;
-use crate::ConvertError;
 use crate::Error;
+use d_engine_proto::common::Entry;
+use d_engine_proto::common::LogId;
+use d_engine_proto::server::storage::SnapshotMetadata;
+use tonic::async_trait;
 
-#[cfg_attr(test, automock)]
+#[cfg_attr(any(test, feature = "test-utils"), automock)]
 #[async_trait]
 pub trait StateMachine: Send + Sync + 'static {
     /// Starts the state machine service.
@@ -157,22 +157,3 @@ pub trait StateMachine: Send + Sync + 'static {
     /// Async operation as it may involve cleaning up files and data.
     async fn reset(&self) -> Result<(), Error>;
 }
-
-impl SnapshotMetadata {
-    pub fn checksum_array(&self) -> Result<[u8; 32], Error> {
-        if self.checksum.len() == 32 {
-            let mut array = [0u8; 32];
-            array.copy_from_slice(&self.checksum);
-            Ok(array)
-        } else {
-            Err(ConvertError::ConversionFailure("Invalid checksum length".to_string()).into())
-        }
-    }
-
-    pub fn set_checksum_array(
-        &mut self,
-        array: [u8; 32],
-    ) {
-        self.checksum = Bytes::copy_from_slice(&array);
-    }
-}
diff --git a/src/storage/state_machine_test.rs b/d-engine-core/src/storage/state_machine_test.rs
similarity index 97%
rename from src/storage/state_machine_test.rs
rename to d-engine-core/src/storage/state_machine_test.rs
index 9638f259..8ced4d23 100644
--- a/src/storage/state_machine_test.rs
+++ b/d-engine-core/src/storage/state_machine_test.rs
@@ -5,17 +5,17 @@ use prost::Message;
 use tempfile::TempDir;
 use tonic::async_trait;
 
-use crate::proto::client::write_command::Delete;
-use crate::proto::client::write_command::Insert;
-use crate::proto::client::write_command::Operation;
-use crate::proto::client::WriteCommand;
-use crate::proto::common::entry_payload::Payload;
-use crate::proto::common::Entry;
-use crate::proto::common::EntryPayload;
-use crate::proto::common::LogId;
-use crate::proto::storage::SnapshotMetadata;
-use crate::storage::StateMachine;
 use crate::Error;
+use crate::storage::StateMachine;
+use d_engine_proto::client::WriteCommand;
+use d_engine_proto::client::write_command::Delete;
+use d_engine_proto::client::write_command::Insert;
+use d_engine_proto::client::write_command::Operation;
+use d_engine_proto::common::Entry;
+use d_engine_proto::common::EntryPayload;
+use d_engine_proto::common::LogId;
+use d_engine_proto::common::entry_payload::Payload;
+use d_engine_proto::server::storage::SnapshotMetadata;
 
 /// Test suite for StateMachine implementations
 ///
diff --git a/src/storage/storage_engine.rs b/d-engine-core/src/storage/storage_engine.rs
similarity index 90%
rename from src/storage/storage_engine.rs
rename to d-engine-core/src/storage/storage_engine.rs
index e1ca6280..dc652f1a 100644
--- a/src/storage/storage_engine.rs
+++ b/d-engine-core/src/storage/storage_engine.rs
@@ -1,16 +1,16 @@
-#![doc = include_str!("../docs/server_guide/customize-storage-engine.md")]
+#![doc = include_str!("../../../d-engine-docs/src/docs/server_guide/customize-storage-engine.md")]
 
 use std::ops::RangeInclusive;
 use std::sync::Arc;
 
-#[cfg(test)]
+#[cfg(any(test, feature = "test-utils"))]
 use mockall::automock;
 use tonic::async_trait;
 
-use crate::proto::common::Entry;
-use crate::proto::common::LogId;
 use crate::Error;
 use crate::HardState;
+use d_engine_proto::common::Entry;
+use d_engine_proto::common::LogId;
 
 /// High-performance storage abstraction for Raft consensus
 ///
@@ -33,7 +33,7 @@ pub trait StorageEngine: Send + Sync + 'static {
     fn meta_store(&self) -> Arc<Self::MetaStore>;
 }
 
-#[cfg_attr(test, automock)]
+#[cfg_attr(any(test, feature = "test-utils"), automock)]
 #[async_trait]
 pub trait LogStore: Send + Sync + 'static {
     /// Batch persist entries into disk (optimized for sequential writes)
@@ -93,7 +93,7 @@ pub trait LogStore: Send + Sync + 'static {
 }
 
 /// Metadata storage operations
-#[cfg_attr(test, automock)]
+#[cfg_attr(any(test, feature = "test-utils"), automock)]
 #[async_trait]
 pub trait MetaStore: Send + Sync + 'static {
     /// Atomically persist hard state (current term and votedFor)
diff --git a/src/storage/storage_engine_test.rs b/d-engine-core/src/storage/storage_engine_test.rs
similarity index 94%
rename from src/storage/storage_engine_test.rs
rename to d-engine-core/src/storage/storage_engine_test.rs
index dd33a930..d636380c 100644
--- a/src/storage/storage_engine_test.rs
+++ b/d-engine-core/src/storage/storage_engine_test.rs
@@ -5,15 +5,15 @@ use bytes::Bytes;
 use prost::Message;
 use tonic::async_trait;
 
-use crate::proto::client::write_command::Insert;
-use crate::proto::common::Entry;
-use crate::proto::common::LogId;
-use crate::proto::election::VotedFor;
-use crate::storage::StorageEngine;
 use crate::Error;
 use crate::HardState;
 use crate::LogStore;
 use crate::MetaStore;
+use crate::storage::StorageEngine;
+use d_engine_proto::client::write_command::Insert;
+use d_engine_proto::common::Entry;
+use d_engine_proto::common::LogId;
+use d_engine_proto::server::election::VotedFor;
 
 /// Test suite for StorageEngine implementations
 ///
@@ -280,21 +280,21 @@ fn create_test_entries(range: RangeInclusive<u64>) -> Vec<Entry> {
 }
 
 /// Helper function to create test command payload
-fn create_test_command_payload(index: u64) -> crate::proto::common::EntryPayload {
+fn create_test_command_payload(index: u64) -> d_engine_proto::common::EntryPayload {
     // Create a simple insert command
     let key = Bytes::from(format!("key_{index}"));
     let value = Bytes::from(format!("value_{index}"));
 
     let insert = Insert { key, value };
-    let operation = crate::proto::client::write_command::Operation::Insert(insert);
-    let write_cmd = crate::proto::client::WriteCommand {
+    let operation = d_engine_proto::client::write_command::Operation::Insert(insert);
+    let write_cmd = d_engine_proto::client::WriteCommand {
         operation: Some(operation),
     };
     let mut buf = Vec::new();
     write_cmd.encode(&mut buf).expect("Failed to encode WriteCommand");
     let cmd_bytes = Bytes::from(buf); // convert Vec<u8> to Bytes
-    crate::proto::common::EntryPayload {
-        payload: Some(crate::proto::common::entry_payload::Payload::Command(
+    d_engine_proto::common::EntryPayload {
+        payload: Some(d_engine_proto::common::entry_payload::Payload::Command(
             cmd_bytes,
         )),
     }
diff --git a/src/storage/storage_test.rs b/d-engine-core/src/storage/storage_test.rs
similarity index 92%
rename from src/storage/storage_test.rs
rename to d-engine-core/src/storage/storage_test.rs
index 37fef370..46b0273a 100644
--- a/src/storage/storage_test.rs
+++ b/d-engine-core/src/storage/storage_test.rs
@@ -1,11 +1,11 @@
 use super::*;
 use crate::convert::safe_kv;
 use crate::convert::skv;
-use crate::proto::cluster::ClusterMembership;
-use crate::proto::cluster::NodeMeta;
-use crate::proto::common::NodeStatus;
-use crate::FOLLOWER;
-use crate::LEARNER;
+use d_engine_proto::cluster::ClusterMembership;
+use d_engine_proto::cluster::NodeMeta;
+use d_engine_proto::common::NodeRole::Follower;
+use d_engine_proto::common::NodeRole::Learner;
+use d_engine_proto::common::NodeStatus;
 
 /// # Case 1: restart
 ///
diff --git a/src/test_utils/common.rs b/d-engine-core/src/test_utils/common.rs
similarity index 54%
rename from src/test_utils/common.rs
rename to d-engine-core/src/test_utils/common.rs
index 9904cc4e..7ceaf277 100644
--- a/src/test_utils/common.rs
+++ b/d-engine-core/src/test_utils/common.rs
@@ -1,24 +1,16 @@
-use std::ops::RangeInclusive;
-use std::path::PathBuf;
-use std::sync::Arc;
-use std::time::Duration;
-
+use crate::SnapshotConfig;
+use crate::convert::safe_kv_bytes;
 use bytes::Bytes;
 use bytes::BytesMut;
+use d_engine_proto::client::WriteCommand;
+use d_engine_proto::common::AddNode;
+use d_engine_proto::common::Entry;
+use d_engine_proto::common::EntryPayload;
+use d_engine_proto::common::membership_change::Change;
 use prost::Message;
-
-use crate::alias::ROF;
-use crate::convert::safe_kv_bytes;
-use crate::proto::client::WriteCommand;
-use crate::proto::common::membership_change::Change;
-use crate::proto::common::AddNode;
-use crate::proto::common::Entry;
-use crate::proto::common::EntryPayload;
-use crate::FileStorageEngine;
-use crate::MockStateMachine;
-use crate::RaftLog;
-use crate::RaftTypeConfig;
-use crate::SnapshotConfig;
+use std::ops::RangeInclusive;
+use std::path::PathBuf;
+use std::time::Duration;
 
 pub fn create_mixed_entries() -> Vec<Entry> {
     let config_entry = Entry {
@@ -51,7 +43,7 @@ pub fn create_config_entries() -> Vec<Entry> {
     vec![entry]
 }
 
-pub(crate) fn generate_insert_commands(ids: Vec<u64>) -> Bytes {
+pub fn generate_insert_commands(ids: Vec<u64>) -> Bytes {
     let mut buffer = BytesMut::new();
 
     for id in ids {
@@ -62,7 +54,7 @@ pub(crate) fn generate_insert_commands(ids: Vec<u64>) -> Bytes {
     buffer.freeze()
 }
 
-pub(crate) fn generate_delete_commands(range: RangeInclusive<u64>) -> Bytes {
+pub fn generate_delete_commands(range: RangeInclusive<u64>) -> Bytes {
     let mut buffer = BytesMut::new();
 
     for id in range {
@@ -72,45 +64,6 @@ pub(crate) fn generate_delete_commands(range: RangeInclusive<u64>) -> Bytes {
 
     buffer.freeze()
 }
-///Dependes on external id to specify the local log entry index.
-/// If duplicated ids are specified, then the only one entry will be inserted.
-pub(crate) async fn simulate_insert_command(
-    raft_log: &Arc<ROF<RaftTypeConfig<FileStorageEngine, MockStateMachine>>>,
-    ids: Vec<u64>,
-    term: u64,
-) {
-    let mut entries = Vec::new();
-    for id in ids {
-        let log = Entry {
-            index: raft_log.pre_allocate_raft_logs_next_index(),
-            term,
-            payload: Some(EntryPayload::command(generate_insert_commands(vec![id]))),
-        };
-        entries.push(log);
-    }
-    raft_log.insert_batch(entries).await.unwrap();
-    raft_log.flush().await.unwrap();
-}
-
-#[allow(dead_code)]
-pub(crate) async fn simulate_delete_command(
-    raft_log: &Arc<ROF<RaftTypeConfig<FileStorageEngine, MockStateMachine>>>,
-    id_range: RangeInclusive<u64>,
-    term: u64,
-) {
-    let mut entries = Vec::new();
-    for id in id_range {
-        let log = Entry {
-            index: raft_log.pre_allocate_raft_logs_next_index(),
-            term,
-            payload: Some(EntryPayload::command(generate_delete_commands(id..=id))),
-        };
-        entries.push(log);
-    }
-    if let Err(e) = raft_log.insert_batch(entries).await {
-        panic!("error: {e:?}");
-    }
-}
 
 pub fn snapshot_config(snapshots_dir: PathBuf) -> SnapshotConfig {
     SnapshotConfig {
@@ -132,5 +85,6 @@ pub fn snapshot_config(snapshots_dir: PathBuf) -> SnapshotConfig {
         snapshot_push_max_retry: 1,
         push_timeout_in_ms: 100,
         enable: true,
+        snapshots_dir_prefix: "snapshot-".to_string(),
     }
 }
diff --git a/d-engine-core/src/test_utils/common_test.rs b/d-engine-core/src/test_utils/common_test.rs
new file mode 100644
index 00000000..e0a65c5e
--- /dev/null
+++ b/d-engine-core/src/test_utils/common_test.rs
@@ -0,0 +1,241 @@
+use crate::test_utils::{
+    create_config_entries, create_mixed_entries, generate_delete_commands,
+    generate_insert_commands, node_config, snapshot_config,
+};
+use std::path::PathBuf;
+
+#[test]
+fn test_create_mixed_entries_structure() {
+    let entries = create_mixed_entries();
+
+    assert_eq!(entries.len(), 2);
+    assert_eq!(entries[0].index, 1);
+    assert_eq!(entries[0].term, 1);
+    assert_eq!(entries[1].index, 2);
+    assert_eq!(entries[1].term, 1);
+}
+
+#[test]
+fn test_create_mixed_entries_config_entry() {
+    let entries = create_mixed_entries();
+    let first_entry = &entries[0];
+
+    assert!(first_entry.payload.is_some());
+}
+
+#[test]
+fn test_create_mixed_entries_app_entry() {
+    let entries = create_mixed_entries();
+    let second_entry = &entries[1];
+
+    assert!(second_entry.payload.is_some());
+    assert_eq!(second_entry.index, 2);
+}
+
+#[test]
+fn test_create_config_entries_count() {
+    let entries = create_config_entries();
+
+    assert_eq!(entries.len(), 1);
+}
+
+#[test]
+fn test_create_config_entries_values() {
+    let entries = create_config_entries();
+    let entry = &entries[0];
+
+    assert_eq!(entry.index, 1);
+    assert_eq!(entry.term, 1);
+    assert!(entry.payload.is_some());
+}
+
+#[test]
+fn test_generate_insert_commands_single() {
+    let commands = generate_insert_commands(vec![42]);
+
+    assert!(!commands.is_empty());
+}
+
+#[test]
+fn test_generate_insert_commands_multiple() {
+    let ids = vec![1, 2, 3, 4, 5];
+    let commands = generate_insert_commands(ids);
+
+    assert!(!commands.is_empty());
+}
+
+#[test]
+fn test_generate_insert_commands_empty() {
+    let commands = generate_insert_commands(vec![]);
+
+    assert!(commands.is_empty());
+}
+
+#[test]
+fn test_generate_insert_commands_large_id() {
+    let commands = generate_insert_commands(vec![u64::MAX]);
+
+    assert!(!commands.is_empty());
+}
+
+#[test]
+fn test_generate_insert_commands_zero_id() {
+    let commands = generate_insert_commands(vec![0]);
+
+    assert!(!commands.is_empty());
+}
+
+#[test]
+fn test_generate_delete_commands_range() {
+    let commands = generate_delete_commands(1..=5);
+
+    assert!(!commands.is_empty());
+}
+
+#[test]
+fn test_generate_delete_commands_single_element() {
+    let commands = generate_delete_commands(1..=1);
+
+    assert!(!commands.is_empty());
+}
+
+#[test]
+fn test_generate_delete_commands_large_range() {
+    let commands = generate_delete_commands(1..=100);
+
+    assert!(!commands.is_empty());
+}
+
+#[test]
+fn test_snapshot_config_defaults() {
+    let dir = PathBuf::from("/tmp/snapshots");
+    let config = snapshot_config(dir.clone());
+
+    assert_eq!(config.max_log_entries_before_snapshot, 1);
+    assert_eq!(config.cleanup_retain_count, 2);
+    assert_eq!(config.chunk_size, 1024);
+    assert!(config.enable);
+    assert_eq!(config.snapshots_dir, dir);
+}
+
+#[test]
+fn test_snapshot_config_paths() {
+    let dir = PathBuf::from("/var/raft/snapshots");
+    let config = snapshot_config(dir.clone());
+
+    assert_eq!(config.snapshots_dir, dir);
+    assert_eq!(config.snapshots_dir_prefix, "snapshot-");
+}
+
+#[test]
+fn test_snapshot_config_timeout_values() {
+    let dir = PathBuf::from("/tmp");
+    let config = snapshot_config(dir);
+
+    assert_eq!(config.transfer_timeout_in_sec, 1);
+    assert_eq!(config.retry_interval_in_ms, 1);
+    assert_eq!(config.push_timeout_in_ms, 100);
+}
+
+#[test]
+fn test_snapshot_config_bandwidth() {
+    let dir = PathBuf::from("/tmp");
+    let config = snapshot_config(dir);
+
+    assert_eq!(config.max_bandwidth_mbps, 1);
+    assert_eq!(config.max_retries, 1);
+}
+
+#[test]
+fn test_snapshot_config_queue_settings() {
+    let dir = PathBuf::from("/tmp");
+    let config = snapshot_config(dir);
+
+    assert_eq!(config.push_queue_size, 1);
+    assert_eq!(config.cache_size, 1);
+}
+
+#[test]
+fn test_snapshot_config_yield_settings() {
+    let dir = PathBuf::from("/tmp");
+    let config = snapshot_config(dir);
+
+    assert_eq!(config.sender_yield_every_n_chunks, 1);
+    assert_eq!(config.receiver_yield_every_n_chunks, 1);
+}
+
+#[test]
+fn test_node_config_initialization() {
+    let config = node_config("/tmp/raft");
+
+    assert_eq!(
+        config.cluster.db_root_dir,
+        std::path::PathBuf::from("/tmp/raft")
+    );
+}
+
+#[test]
+fn test_node_config_different_paths() {
+    let path1 = "/data/raft1";
+    let path2 = "/data/raft2";
+
+    let config1 = node_config(path1);
+    let config2 = node_config(path2);
+
+    assert_eq!(config1.cluster.db_root_dir, std::path::PathBuf::from(path1));
+    assert_eq!(config2.cluster.db_root_dir, std::path::PathBuf::from(path2));
+    assert_ne!(config1.cluster.db_root_dir, config2.cluster.db_root_dir);
+}
+
+#[test]
+fn test_node_config_absolute_path() {
+    let path = "/absolute/path/to/db";
+    let config = node_config(path);
+
+    assert!(config.cluster.db_root_dir.is_absolute());
+}
+
+#[test]
+fn test_node_config_relative_path() {
+    let path = "./relative/db";
+    let config = node_config(path);
+
+    assert_eq!(config.cluster.db_root_dir, std::path::PathBuf::from(path));
+}
+
+#[test]
+fn test_generate_insert_commands_consistency() {
+    let ids = vec![10, 20, 30];
+    let cmd1 = generate_insert_commands(ids.clone());
+    let cmd2 = generate_insert_commands(ids);
+
+    assert_eq!(cmd1.len(), cmd2.len());
+}
+
+#[test]
+fn test_generate_delete_commands_consistency() {
+    let cmd1 = generate_delete_commands(5..=10);
+    let cmd2 = generate_delete_commands(5..=10);
+
+    assert_eq!(cmd1.len(), cmd2.len());
+}
+
+#[test]
+fn test_snapshot_config_immutable_after_creation() {
+    let dir = PathBuf::from("/tmp");
+    let config = snapshot_config(dir.clone());
+
+    let max_entries = config.max_log_entries_before_snapshot;
+    let chunk_sz = config.chunk_size;
+
+    assert_eq!(max_entries, 1);
+    assert_eq!(chunk_sz, 1024);
+}
+
+#[test]
+fn test_create_mixed_entries_ordering() {
+    let entries = create_mixed_entries();
+
+    assert!(entries[0].index < entries[1].index);
+    assert_eq!(entries[0].term, entries[1].term);
+}
diff --git a/src/test_utils/entry_builder.rs b/d-engine-core/src/test_utils/entry_builder.rs
similarity index 89%
rename from src/test_utils/entry_builder.rs
rename to d-engine-core/src/test_utils/entry_builder.rs
index 1fdee32a..bf2eb9d1 100644
--- a/src/test_utils/entry_builder.rs
+++ b/d-engine-core/src/test_utils/entry_builder.rs
@@ -1,8 +1,8 @@
 use bytes::Bytes;
 
-use crate::proto::common::membership_change::Change;
-use crate::proto::common::Entry;
-use crate::proto::common::EntryPayload;
+use d_engine_proto::common::Entry;
+use d_engine_proto::common::EntryPayload;
+use d_engine_proto::common::membership_change::Change;
 
 pub struct EntryBuilder {
     index: u64,
diff --git a/d-engine-core/src/test_utils/entry_builder_test.rs b/d-engine-core/src/test_utils/entry_builder_test.rs
new file mode 100644
index 00000000..23b33836
--- /dev/null
+++ b/d-engine-core/src/test_utils/entry_builder_test.rs
@@ -0,0 +1,213 @@
+use crate::test_utils::EntryBuilder;
+use d_engine_proto::common::{AddNode, RemoveNode, membership_change::Change};
+
+#[test]
+fn test_entry_builder_creation() {
+    let builder = EntryBuilder::new(1, 1);
+    let (_, entry) = builder.noop();
+
+    assert_eq!(entry.index, 1);
+    assert_eq!(entry.term, 1);
+}
+
+#[test]
+fn test_entry_builder_command_single() {
+    let builder = EntryBuilder::new(1, 1);
+    let (_, entry) = builder.command(b"test_command");
+
+    assert_eq!(entry.index, 1);
+    assert_eq!(entry.term, 1);
+    assert!(entry.payload.is_some());
+}
+
+#[test]
+fn test_entry_builder_command_chain() {
+    let builder = EntryBuilder::new(1, 1);
+    let (builder, entry1) = builder.command(b"cmd1");
+    let (_, entry2) = builder.command(b"cmd2");
+
+    assert_eq!(entry1.index, 1);
+    assert_eq!(entry2.index, 2);
+}
+
+#[test]
+fn test_entry_builder_noop_single() {
+    let builder = EntryBuilder::new(5, 3);
+    let (_, entry) = builder.noop();
+
+    assert_eq!(entry.index, 5);
+    assert_eq!(entry.term, 3);
+    assert!(entry.payload.is_some());
+}
+
+#[test]
+fn test_entry_builder_config_add_node() {
+    let builder = EntryBuilder::new(1, 1);
+    let change = Change::AddNode(AddNode {
+        node_id: 2,
+        address: "127.0.0.1:8080".to_string(),
+    });
+    let (_, entry) = builder.config(change);
+
+    assert_eq!(entry.index, 1);
+    assert_eq!(entry.term, 1);
+    assert!(entry.payload.is_some());
+}
+
+#[test]
+fn test_entry_builder_config_remove_node() {
+    let builder = EntryBuilder::new(10, 2);
+    let change = Change::RemoveNode(RemoveNode { node_id: 3 });
+    let (_, entry) = builder.config(change);
+
+    assert_eq!(entry.index, 10);
+    assert_eq!(entry.term, 2);
+    assert!(entry.payload.is_some());
+}
+
+#[test]
+fn test_entry_builder_mixed_sequence() {
+    let builder = EntryBuilder::new(1, 1);
+    let (builder, cmd_entry) = builder.command(b"test");
+    let (builder, noop_entry) = builder.noop();
+    let change = Change::AddNode(AddNode {
+        node_id: 5,
+        address: "192.168.1.1:9000".to_string(),
+    });
+    let (_, config_entry) = builder.config(change);
+
+    assert_eq!(cmd_entry.index, 1);
+    assert_eq!(noop_entry.index, 2);
+    assert_eq!(config_entry.index, 3);
+
+    assert_eq!(cmd_entry.term, 1);
+    assert_eq!(noop_entry.term, 1);
+    assert_eq!(config_entry.term, 1);
+}
+
+#[test]
+fn test_entry_builder_index_increments() {
+    let builder = EntryBuilder::new(100, 5);
+    let (builder, entry1) = builder.noop();
+    let (builder, entry2) = builder.noop();
+    let (builder, entry3) = builder.noop();
+    let (_, entry4) = builder.noop();
+
+    assert_eq!(entry1.index, 100);
+    assert_eq!(entry2.index, 101);
+    assert_eq!(entry3.index, 102);
+    assert_eq!(entry4.index, 103);
+}
+
+#[test]
+fn test_entry_builder_term_constant() {
+    let builder = EntryBuilder::new(1, 5);
+    let (builder, entry1) = builder.noop();
+    let (builder, entry2) = builder.command(b"data");
+    let (_, entry3) = builder.noop();
+
+    assert_eq!(entry1.term, 5);
+    assert_eq!(entry2.term, 5);
+    assert_eq!(entry3.term, 5);
+}
+
+#[test]
+fn test_entry_builder_command_empty_data() {
+    let builder = EntryBuilder::new(1, 1);
+    let (_, entry) = builder.command(b"");
+
+    assert!(entry.payload.is_some());
+}
+
+#[test]
+fn test_entry_builder_command_large_data() {
+    let large_data = vec![0u8; 10000];
+    let builder = EntryBuilder::new(1, 1);
+    let (_, entry) = builder.command(&large_data);
+
+    assert!(entry.payload.is_some());
+}
+
+#[test]
+fn test_entry_builder_high_index() {
+    let builder = EntryBuilder::new(u64::MAX - 2, 1);
+    let (builder, entry1) = builder.noop();
+    let (_, entry2) = builder.noop();
+
+    assert_eq!(entry1.index, u64::MAX - 2);
+    assert_eq!(entry2.index, u64::MAX - 1);
+}
+
+#[test]
+fn test_entry_builder_high_term() {
+    let builder = EntryBuilder::new(1, u64::MAX);
+    let (_, entry) = builder.noop();
+
+    assert_eq!(entry.term, u64::MAX);
+}
+
+#[test]
+fn test_entry_builder_zero_index() {
+    let builder = EntryBuilder::new(0, 1);
+    let (_, entry) = builder.noop();
+
+    assert_eq!(entry.index, 0);
+}
+
+#[test]
+fn test_entry_builder_zero_term() {
+    let builder = EntryBuilder::new(1, 0);
+    let (_, entry) = builder.noop();
+
+    assert_eq!(entry.term, 0);
+}
+
+#[test]
+fn test_entry_builder_command_binary_data() {
+    let binary_data = vec![0xFF, 0xFE, 0xFD, 0xFC];
+    let builder = EntryBuilder::new(1, 1);
+    let (_, entry) = builder.command(&binary_data);
+
+    assert!(entry.payload.is_some());
+}
+
+#[test]
+fn test_entry_builder_multiple_commands() {
+    let builder = EntryBuilder::new(1, 1);
+    let (builder, e1) = builder.command(b"cmd1");
+    let (builder, e2) = builder.command(b"cmd2");
+    let (builder, e3) = builder.command(b"cmd3");
+    let (_, e4) = builder.command(b"cmd4");
+
+    assert_eq!(
+        vec![e1.index, e2.index, e3.index, e4.index],
+        vec![1, 2, 3, 4]
+    );
+}
+
+#[test]
+fn test_entry_builder_payload_types() {
+    let builder = EntryBuilder::new(1, 1);
+    let (builder, cmd_entry) = builder.command(b"data");
+    let (builder, noop_entry) = builder.noop();
+    let change = Change::AddNode(AddNode {
+        node_id: 1,
+        address: "127.0.0.1:5000".to_string(),
+    });
+    let (_, config_entry) = builder.config(change);
+
+    assert!(cmd_entry.payload.is_some());
+    assert!(noop_entry.payload.is_some());
+    assert!(config_entry.payload.is_some());
+}
+
+#[test]
+fn test_entry_builder_state_after_sequence() {
+    let builder = EntryBuilder::new(10, 5);
+    let (builder, _) = builder.noop();
+    let (builder, _) = builder.command(b"test");
+    let (_, last_entry) = builder.noop();
+
+    assert_eq!(last_entry.index, 12);
+    assert_eq!(last_entry.term, 5);
+}
diff --git a/src/test_utils/mock/mock_builder.rs b/d-engine-core/src/test_utils/mock/mock_raft_builder.rs
similarity index 85%
rename from src/test_utils/mock/mock_builder.rs
rename to d-engine-core/src/test_utils/mock/mock_raft_builder.rs
index a10a30e5..3b0612c0 100644
--- a/src/test_utils/mock/mock_builder.rs
+++ b/d-engine-core/src/test_utils/mock/mock_raft_builder.rs
@@ -1,19 +1,10 @@
+use bytes::Bytes;
 use std::path::Path;
-use std::sync::atomic::AtomicBool;
 use std::sync::Arc;
-
-use bytes::Bytes;
 use tokio::sync::mpsc;
 use tokio::sync::watch;
-use tokio::sync::Mutex;
-use tracing::error;
 use tracing::trace;
 
-use super::MockTypeConfig;
-use crate::follower_state::FollowerState;
-use crate::grpc;
-use crate::proto::cluster::ClusterMembership;
-use crate::proto::common::LogId;
 use crate::ElectionConfig;
 use crate::MockElectionCore;
 use crate::MockMembership;
@@ -23,7 +14,7 @@ use crate::MockReplicationCore;
 use crate::MockStateMachine;
 use crate::MockStateMachineHandler;
 use crate::MockTransport;
-use crate::Node;
+use crate::MockTypeConfig;
 use crate::Raft;
 use crate::RaftConfig;
 use crate::RaftContext;
@@ -36,6 +27,9 @@ use crate::RaftStorageHandles;
 use crate::RoleEvent;
 use crate::SignalParams;
 use crate::StateMachine;
+use crate::follower_state::FollowerState;
+use d_engine_proto::common::LogId;
+use d_engine_proto::server::cluster::ClusterMembership;
 
 pub struct MockBuilder {
     pub id: Option<u32>,
@@ -83,7 +77,7 @@ impl MockBuilder {
         }
     }
 
-    pub(crate) fn build_context(self) -> RaftContext<MockTypeConfig> {
+    pub fn build_context(self) -> RaftContext<MockTypeConfig> {
         let (
             raft_log,
             state_machine,
@@ -213,57 +207,6 @@ impl MockBuilder {
         )
     }
 
-    pub fn build_node(self) -> Node<MockTypeConfig> {
-        let raft = self.build_raft();
-        let event_tx = raft.event_tx.clone();
-        let node_config = raft.ctx.node_config.clone();
-        let membership = raft.ctx.membership.clone();
-        Node::<MockTypeConfig> {
-            node_id: raft.node_id,
-            raft_core: Arc::new(Mutex::new(raft)),
-            membership,
-            event_tx,
-            ready: AtomicBool::new(false),
-            node_config,
-        }
-    }
-
-    pub fn build_node_with_rpc_server(self) -> Arc<Node<MockTypeConfig>> {
-        let shutdown = self.shutdown_signal.clone();
-        let node_config_option = self.node_config.clone();
-
-        let raft = self.build_raft();
-        let event_tx = raft.event_tx.clone();
-        let node_config = node_config_option.unwrap_or_else(|| {
-            RaftNodeConfig::new().expect("Should succeed to init RaftNodeConfig")
-        });
-        let membership = raft.ctx.membership.clone();
-        trace!(
-            node_config.raft.election.election_timeout_min,
-            "build_node_with_rpc_server"
-        );
-        let node = Arc::new(Node::<MockTypeConfig> {
-            node_id: raft.node_id,
-            raft_core: Arc::new(Mutex::new(raft)),
-            membership,
-            event_tx,
-            ready: AtomicBool::new(false),
-            node_config: Arc::new(node_config.clone()),
-        });
-        let node_clone = node.clone();
-        let listen_address = node_config.cluster.listen_address;
-        let node_config = node_config.clone();
-        tokio::spawn(async move {
-            if let Err(e) =
-                grpc::start_rpc_server(node_clone, listen_address, node_config, shutdown).await
-            {
-                eprintln!("RPC server stops. {e:?}");
-                error!("RPC server stops. {e:?}");
-            }
-        });
-
-        node
-    }
     pub fn id(
         mut self,
         id: u32,
diff --git a/src/test_utils/mock/mock_rpc.rs b/d-engine-core/src/test_utils/mock/mock_rpc.rs
similarity index 81%
rename from src/test_utils/mock/mock_rpc.rs
rename to d-engine-core/src/test_utils/mock/mock_rpc.rs
index 70155010..ad9dbed0 100644
--- a/src/test_utils/mock/mock_rpc.rs
+++ b/d-engine-core/src/test_utils/mock/mock_rpc.rs
@@ -4,32 +4,32 @@ use tokio_stream::StreamExt;
 use tonic::Streaming;
 use tracing::trace;
 
-use crate::proto::client::raft_client_service_server::RaftClientService;
-use crate::proto::client::ClientReadRequest;
-use crate::proto::client::ClientResponse;
-use crate::proto::client::ClientWriteRequest;
-use crate::proto::cluster::cluster_management_service_server::ClusterManagementService;
-use crate::proto::cluster::ClusterConfChangeRequest;
-use crate::proto::cluster::ClusterConfUpdateResponse;
-use crate::proto::cluster::ClusterMembership;
-use crate::proto::cluster::JoinRequest;
-use crate::proto::cluster::JoinResponse;
-use crate::proto::cluster::LeaderDiscoveryRequest;
-use crate::proto::cluster::LeaderDiscoveryResponse;
-use crate::proto::cluster::MetadataRequest;
-use crate::proto::election::raft_election_service_server::RaftElectionService;
-use crate::proto::election::VoteRequest;
-use crate::proto::election::VoteResponse;
-use crate::proto::replication::raft_replication_service_server::RaftReplicationService;
-use crate::proto::replication::AppendEntriesRequest;
-use crate::proto::replication::AppendEntriesResponse;
-use crate::proto::storage::snapshot_service_server::SnapshotService;
-use crate::proto::storage::PurgeLogRequest;
-use crate::proto::storage::PurgeLogResponse;
-use crate::proto::storage::SnapshotAck;
-use crate::proto::storage::SnapshotChunk;
-use crate::proto::storage::SnapshotResponse;
-use crate::test_utils::crate_test_snapshot_stream;
+use crate::test_utils::create_test_snapshot_stream;
+use d_engine_proto::client::ClientReadRequest;
+use d_engine_proto::client::ClientResponse;
+use d_engine_proto::client::ClientWriteRequest;
+use d_engine_proto::client::raft_client_service_server::RaftClientService;
+use d_engine_proto::server::cluster::ClusterConfChangeRequest;
+use d_engine_proto::server::cluster::ClusterConfUpdateResponse;
+use d_engine_proto::server::cluster::ClusterMembership;
+use d_engine_proto::server::cluster::JoinRequest;
+use d_engine_proto::server::cluster::JoinResponse;
+use d_engine_proto::server::cluster::LeaderDiscoveryRequest;
+use d_engine_proto::server::cluster::LeaderDiscoveryResponse;
+use d_engine_proto::server::cluster::MetadataRequest;
+use d_engine_proto::server::cluster::cluster_management_service_server::ClusterManagementService;
+use d_engine_proto::server::election::VoteRequest;
+use d_engine_proto::server::election::VoteResponse;
+use d_engine_proto::server::election::raft_election_service_server::RaftElectionService;
+use d_engine_proto::server::replication::AppendEntriesRequest;
+use d_engine_proto::server::replication::AppendEntriesResponse;
+use d_engine_proto::server::replication::raft_replication_service_server::RaftReplicationService;
+use d_engine_proto::server::storage::PurgeLogRequest;
+use d_engine_proto::server::storage::PurgeLogResponse;
+use d_engine_proto::server::storage::SnapshotAck;
+use d_engine_proto::server::storage::SnapshotChunk;
+use d_engine_proto::server::storage::SnapshotResponse;
+use d_engine_proto::server::storage::snapshot_service_server::SnapshotService;
 
 #[derive(Clone, Default)]
 pub struct MockRpcService {
@@ -132,9 +132,7 @@ impl ClusterManagementService for MockRpcService {
         match &self.expected_join_cluster_response {
             Some(Ok(response)) => Ok(tonic::Response::new(response.clone())),
             Some(Err(status)) => Err(status.clone()),
-            None => Err(tonic::Status::unknown(
-                "No mock get_cluster_metadata response set",
-            )),
+            None => Err(tonic::Status::unknown("No mock join_cluster response set")),
         }
     }
 
@@ -192,7 +190,7 @@ impl SnapshotService for MockRpcService {
         match &self.expected_stream_snapshot_response {
             Some(Ok(response)) => {
                 let streaming: Self::StreamSnapshotStream =
-                    crate_test_snapshot_stream(vec![response.clone()]);
+                    create_test_snapshot_stream(vec![response.clone()]);
                 Ok(tonic::Response::new(streaming))
             }
             Some(Err(status)) => Err(status.clone()),
@@ -218,7 +216,7 @@ impl SnapshotService for MockRpcService {
             None => {
                 return Err(tonic::Status::unknown(
                     "No mock install_snapshot response set",
-                ))
+                ));
             }
         }
     }
diff --git a/src/test_utils/mock/mock_rpc_service.rs b/d-engine-core/src/test_utils/mock/mock_rpc_service.rs
similarity index 86%
rename from src/test_utils/mock/mock_rpc_service.rs
rename to d-engine-core/src/test_utils/mock/mock_rpc_service.rs
index 3fa4c80f..3615f7b2 100644
--- a/src/test_utils/mock/mock_rpc_service.rs
+++ b/d-engine-core/src/test_utils/mock/mock_rpc_service.rs
@@ -1,36 +1,32 @@
 use std::net::SocketAddr;
 use std::sync::Arc;
-
 use tokio::net::TcpListener;
 use tokio::sync::oneshot;
+use tonic::Status;
 use tonic::codec::CompressionEncoding;
 use tonic::transport::Channel;
-use tonic::Status;
 use tonic_health::server::health_reporter;
 use tracing::debug;
 use tracing::info;
 
 use super::MockRpcService;
-use crate::proto::client::raft_client_service_server::RaftClientServiceServer;
-use crate::proto::client::ClientResponse;
-use crate::proto::cluster::cluster_management_service_server::ClusterManagementServiceServer;
-use crate::proto::cluster::ClusterMembership;
-use crate::proto::cluster::JoinResponse;
-use crate::proto::cluster::NodeMeta;
-use crate::proto::common::NodeStatus;
-use crate::proto::election::raft_election_service_server::RaftElectionServiceServer;
-use crate::proto::election::VoteResponse;
-use crate::proto::replication::raft_replication_service_server::RaftReplicationServiceServer;
-use crate::proto::replication::AppendEntriesResponse;
-use crate::proto::storage::snapshot_service_server::SnapshotServiceServer;
-use crate::proto::storage::PurgeLogResponse;
-use crate::proto::storage::SnapshotResponse;
 use crate::Result;
 use crate::StorageError;
-use crate::LEADER;
-
-// ports for unit tests
-pub(crate) const MOCK_STATE_MACHINE_HANDLER_PORT_BASE: u32 = 60400;
+use d_engine_proto::client::ClientResponse;
+use d_engine_proto::client::raft_client_service_server::RaftClientServiceServer;
+use d_engine_proto::common::NodeRole::Leader;
+use d_engine_proto::common::NodeStatus;
+use d_engine_proto::server::cluster::ClusterMembership;
+use d_engine_proto::server::cluster::JoinResponse;
+use d_engine_proto::server::cluster::NodeMeta;
+use d_engine_proto::server::cluster::cluster_management_service_server::ClusterManagementServiceServer;
+use d_engine_proto::server::election::VoteResponse;
+use d_engine_proto::server::election::raft_election_service_server::RaftElectionServiceServer;
+use d_engine_proto::server::replication::AppendEntriesResponse;
+use d_engine_proto::server::replication::raft_replication_service_server::RaftReplicationServiceServer;
+use d_engine_proto::server::storage::PurgeLogResponse;
+use d_engine_proto::server::storage::SnapshotResponse;
+use d_engine_proto::server::storage::snapshot_service_server::SnapshotServiceServer;
 
 pub struct MockNode;
 
@@ -116,7 +112,7 @@ impl MockNode {
     }
 
     // Update helper functions to handle dynamic ports
-    pub(crate) async fn mock_channel_with_port(port: u16) -> Channel {
+    pub async fn mock_channel_with_port(port: u16) -> Channel {
         Channel::from_shared(format!("http://127.0.0.1:{port}"))
             .expect("valid address")
             .connect()
@@ -124,11 +120,11 @@ impl MockNode {
             .expect("connection failed")
     }
 
-    pub(crate) fn tcp_addr_to_http_addr(addr: String) -> String {
+    pub fn tcp_addr_to_http_addr(addr: String) -> String {
         format!("http://{addr}")
     }
 
-    pub(crate) async fn simulate_send_votes_mock_server(
+    pub async fn simulate_send_votes_mock_server(
         response: VoteResponse,
         rx: oneshot::Receiver<()>,
     ) -> Result<(Channel, u16)> {
@@ -143,7 +139,7 @@ impl MockNode {
         Ok((channel, port))
     }
 
-    pub(crate) async fn simulate_purge_mock_server(
+    pub async fn simulate_purge_mock_server(
         response: PurgeLogResponse,
         rx: oneshot::Receiver<()>,
     ) -> Result<(Channel, u16)> {
@@ -159,7 +155,7 @@ impl MockNode {
     }
 
     // Return channel + port
-    pub(crate) async fn simulate_snapshot_mock_server(
+    pub async fn simulate_snapshot_mock_server(
         response: std::result::Result<SnapshotResponse, tonic::Status>,
         rx: oneshot::Receiver<()>,
     ) -> Result<(Channel, u16)> {
@@ -174,7 +170,7 @@ impl MockNode {
     }
 
     #[allow(clippy::type_complexity)]
-    pub(crate) async fn simulate_mock_service_with_cluster_conf_reps(
+    pub async fn simulate_mock_service_with_cluster_conf_reps(
         rx: oneshot::Receiver<()>,
         response_builder: Option<
             Box<dyn Fn(u16) -> std::result::Result<ClusterMembership, tonic::Status> + Send + Sync>,
@@ -186,7 +182,7 @@ impl MockNode {
                     version: 1,
                     nodes: vec![NodeMeta {
                         id: 1,
-                        role: LEADER,
+                        role: Leader.into(),
                         address: format!("127.0.0.1:{port}",),
                         status: NodeStatus::Active.into(),
                     }],
@@ -201,7 +197,7 @@ impl MockNode {
         Ok((channel, port))
     }
 
-    pub(crate) async fn simulate_append_entries_mock_server(
+    pub async fn simulate_append_entries_mock_server(
         response: std::result::Result<AppendEntriesResponse, Status>,
         rx: oneshot::Receiver<()>,
     ) -> Result<(Channel, u16)> {
@@ -216,7 +212,7 @@ impl MockNode {
     }
 
     #[allow(clippy::type_complexity)]
-    pub(crate) async fn simulate_mock_service_with_join_cluster_reps(
+    pub async fn simulate_mock_service_with_join_cluster_reps(
         rx: oneshot::Receiver<()>,
         metadata_response_builder: Option<
             Box<dyn Fn(u16) -> std::result::Result<ClusterMembership, tonic::Status> + Send + Sync>,
@@ -229,7 +225,7 @@ impl MockNode {
                     version: 1,
                     nodes: vec![NodeMeta {
                         id: 1,
-                        role: LEADER,
+                        role: Leader.into(),
                         address: format!("127.0.0.1:{port}",),
                         status: NodeStatus::Active.into(),
                     }],
@@ -247,7 +243,7 @@ impl MockNode {
     }
 
     #[allow(clippy::type_complexity)]
-    pub(crate) async fn simulate_client_read_mock_server(
+    pub async fn simulate_client_read_mock_server(
         rx: oneshot::Receiver<()>,
         metadata_response_builder: Option<
             Box<dyn Fn(u16) -> std::result::Result<ClusterMembership, tonic::Status> + Send + Sync>,
@@ -260,7 +256,7 @@ impl MockNode {
                     version: 1,
                     nodes: vec![NodeMeta {
                         id: 1,
-                        role: LEADER,
+                        role: Leader.into(),
                         address: format!("127.0.0.1:{port}",),
                         status: NodeStatus::Active.into(),
                     }],
@@ -278,7 +274,7 @@ impl MockNode {
     }
 
     #[allow(clippy::type_complexity)]
-    pub(crate) async fn simulate_client_write_mock_server(
+    pub async fn simulate_client_write_mock_server(
         rx: oneshot::Receiver<()>,
         metadata_response_builder: Option<
             Box<dyn Fn(u16) -> std::result::Result<ClusterMembership, tonic::Status> + Send + Sync>,
@@ -291,7 +287,7 @@ impl MockNode {
                     version: 1,
                     nodes: vec![NodeMeta {
                         id: 1,
-                        role: LEADER,
+                        role: Leader.into(),
                         address: format!("127.0.0.1:{port}",),
                         status: NodeStatus::Active.into(),
                     }],
diff --git a/src/test_utils/mock/mock_storage_engine.rs b/d-engine-core/src/test_utils/mock/mock_storage_engine.rs
similarity index 99%
rename from src/test_utils/mock/mock_storage_engine.rs
rename to d-engine-core/src/test_utils/mock/mock_storage_engine.rs
index 4e5e411c..528bcbae 100644
--- a/src/test_utils/mock/mock_storage_engine.rs
+++ b/d-engine-core/src/test_utils/mock/mock_storage_engine.rs
@@ -1,7 +1,6 @@
 use std::cell::RefCell;
 use std::collections::HashMap;
 use std::sync::Arc;
-
 use uuid::Uuid;
 
 use crate::HardState;
diff --git a/src/test_utils/mock_type_config.rs b/d-engine-core/src/test_utils/mock/mock_type_config.rs
similarity index 97%
rename from src/test_utils/mock_type_config.rs
rename to d-engine-core/src/test_utils/mock/mock_type_config.rs
index 23d1070a..bd23241a 100644
--- a/src/test_utils/mock_type_config.rs
+++ b/d-engine-core/src/test_utils/mock/mock_type_config.rs
@@ -1,4 +1,3 @@
-use super::*;
 use crate::MockCommitHandler;
 use crate::MockElectionCore;
 use crate::MockMembership;
@@ -8,6 +7,7 @@ use crate::MockReplicationCore;
 use crate::MockSnapshotPolicy;
 use crate::MockStateMachine;
 use crate::MockStateMachineHandler;
+use crate::MockStorageEngine;
 use crate::MockTransport;
 use crate::TypeConfig;
 
diff --git a/src/test_utils/mock/mod.rs b/d-engine-core/src/test_utils/mock/mod.rs
similarity index 66%
rename from src/test_utils/mock/mod.rs
rename to d-engine-core/src/test_utils/mock/mod.rs
index 03c4e25f..bf3a896d 100644
--- a/src/test_utils/mock/mod.rs
+++ b/d-engine-core/src/test_utils/mock/mod.rs
@@ -38,54 +38,24 @@
 //!
 //! [mockall]: https://docs.rs/mockall/latest/mockall/
 
-mod mock_builder;
+mod mock_raft_builder;
 mod mock_rpc;
 mod mock_rpc_service;
 mod mock_storage_engine;
+mod mock_type_config;
 
-pub use mock_builder::*;
+pub use mock_raft_builder::*;
 pub use mock_rpc::*;
 pub use mock_rpc_service::*;
 pub use mock_storage_engine::*;
-use tokio::sync::watch;
+pub use mock_type_config::*;
 
 use super::node_config;
-use super::MockTypeConfig;
-use crate::proto::cluster::NodeMeta;
-use crate::Node;
-use crate::Raft;
 use crate::RaftContext;
+use d_engine_proto::server::cluster::NodeMeta;
+use tokio::sync::watch;
 
-pub(crate) fn mock_node(
-    db_path: &str,
-    shutdown_signal: watch::Receiver<()>,
-    peers_meta_option: Option<Vec<NodeMeta>>,
-) -> Node<MockTypeConfig> {
-    let mut node_config = node_config(db_path);
-    if let Some(peers_meta) = peers_meta_option {
-        node_config.cluster.initial_cluster = peers_meta;
-    }
-    // Initializing Shutdown Signal
-    // let (graceful_tx, graceful_rx) = watch::channel(());
-    MockBuilder::new(shutdown_signal).with_node_config(node_config).build_node()
-}
-
-pub(crate) fn mock_raft(
-    db_path: &str,
-    shutdown_signal: watch::Receiver<()>,
-    peers_meta_option: Option<Vec<NodeMeta>>,
-) -> Raft<MockTypeConfig> {
-    let mut node_config = node_config(db_path);
-    // Set batch_threshold=0, means the replication will be triggered immediatelly.
-    node_config.raft.replication.rpc_append_entries_in_batch_threshold = 0;
-    if let Some(peers_meta) = peers_meta_option {
-        node_config.cluster.initial_cluster = peers_meta;
-    }
-
-    MockBuilder::new(shutdown_signal).with_node_config(node_config).build_raft()
-}
-
-pub(crate) fn mock_raft_context(
+pub fn mock_raft_context(
     db_path: &str,
     shutdown_signal: watch::Receiver<()>,
     peers_meta_option: Option<Vec<NodeMeta>>,
diff --git a/d-engine-core/src/test_utils/mod.rs b/d-engine-core/src/test_utils/mod.rs
new file mode 100644
index 00000000..eb838d66
--- /dev/null
+++ b/d-engine-core/src/test_utils/mod.rs
@@ -0,0 +1,24 @@
+//! the test_utils folder here will share utils or test components betwee unit
+//! tests and integrations tests
+mod common;
+mod entry_builder;
+mod mock;
+mod snapshot;
+
+#[cfg(test)]
+mod common_test;
+
+#[cfg(test)]
+mod entry_builder_test;
+
+pub use common::*;
+pub use entry_builder::*;
+pub use mock::*;
+pub use snapshot::*;
+
+pub fn node_config(db_path: &str) -> crate::RaftNodeConfig {
+    let mut s =
+        crate::RaftNodeConfig::new().expect("RaftNodeConfig should be inited successfully.");
+    s.cluster.db_root_dir = std::path::PathBuf::from(db_path);
+    s
+}
diff --git a/src/test_utils/integration/snapshot.rs b/d-engine-core/src/test_utils/snapshot.rs
similarity index 85%
rename from src/test_utils/integration/snapshot.rs
rename to d-engine-core/src/test_utils/snapshot.rs
index 157a9fdb..dd7b0ddf 100644
--- a/src/test_utils/integration/snapshot.rs
+++ b/d-engine-core/src/test_utils/snapshot.rs
@@ -1,16 +1,14 @@
-use std::path::Path;
-
 use bytes::BufMut;
 use bytes::Bytes;
 use bytes::BytesMut;
 use crc32fast::Hasher;
-use futures::stream;
-use futures::stream::BoxStream;
 use futures::StreamExt;
 use futures::TryStreamExt;
+use futures::stream;
 use http_body::Frame;
 use http_body_util::BodyExt;
 use http_body_util::StreamBody;
+use std::path::Path;
 use tokio::fs::File;
 use tokio::io::AsyncWriteExt;
 use tokio::sync::mpsc;
@@ -19,38 +17,12 @@ use tonic::Code;
 use tonic::Status;
 use tracing::debug;
 
-use crate::proto::common::LogId;
-use crate::proto::storage::SnapshotChunk;
-use crate::proto::storage::SnapshotMetadata;
 use crate::stream::GrpcStreamDecoder;
-use crate::NetworkError;
-use crate::Result;
-
-/// Helper to create a valid snapshot stream
-pub(crate) fn create_snapshot_stream(
-    chunks: usize,
-    chunk_size: usize,
-) -> BoxStream<'static, Result<SnapshotChunk>> {
-    let chunks: Vec<SnapshotChunk> = (0..chunks)
-        .map(|seq| {
-            let data = vec![seq as u8; chunk_size];
-            create_test_chunk(
-                seq as u32,
-                &data,
-                1, // term
-                1, // leader_id
-                chunks as u32,
-            )
-        })
-        .collect();
-
-    let stream = crate_test_snapshot_stream(chunks);
-    Box::pin(
-        stream.map(|item| item.map_err(|s| NetworkError::TonicStatusError(Box::new(s)).into())),
-    )
-}
+use d_engine_proto::common::LogId;
+use d_engine_proto::server::storage::SnapshotChunk;
+use d_engine_proto::server::storage::SnapshotMetadata;
 
-pub(crate) fn crate_test_snapshot_stream<T>(chunks: Vec<T>) -> tonic::Streaming<T>
+pub fn create_test_snapshot_stream<T>(chunks: Vec<T>) -> tonic::Streaming<T>
 where
     T: prost::Message + Default + 'static,
 {
@@ -130,7 +102,7 @@ pub async fn create_test_compressed_snapshot() -> (Vec<u8>, SnapshotMetadata) {
 }
 
 #[allow(unused)]
-pub(crate) fn crate_test_snapshot_stream_from_receiver<T>(
+pub(crate) fn create_test_snapshot_stream_from_receiver<T>(
     receiver: mpsc::Receiver<T>
 ) -> tonic::Streaming<T>
 where
@@ -163,7 +135,7 @@ where
 }
 
 /// Helper to create valid test chunk
-pub(crate) fn create_test_chunk(
+pub fn create_test_chunk(
     seq: u32,
     data: &[u8],
     leader_term: u64,
diff --git a/src/core/timer/election_timer.rs b/d-engine-core/src/timer/election_timer.rs
similarity index 100%
rename from src/core/timer/election_timer.rs
rename to d-engine-core/src/timer/election_timer.rs
diff --git a/src/core/timer/mod.rs b/d-engine-core/src/timer/mod.rs
similarity index 100%
rename from src/core/timer/mod.rs
rename to d-engine-core/src/timer/mod.rs
diff --git a/src/core/timer/replication_timer.rs b/d-engine-core/src/timer/replication_timer.rs
similarity index 100%
rename from src/core/timer/replication_timer.rs
rename to d-engine-core/src/timer/replication_timer.rs
diff --git a/src/type_config.rs b/d-engine-core/src/type_config.rs
similarity index 100%
rename from src/type_config.rs
rename to d-engine-core/src/type_config.rs
diff --git a/d-engine-core/src/utils/cluster.rs b/d-engine-core/src/utils/cluster.rs
new file mode 100644
index 00000000..d809c6d5
--- /dev/null
+++ b/d-engine-core/src/utils/cluster.rs
@@ -0,0 +1,45 @@
+use tracing::error;
+
+use d_engine_proto::common::NodeRole::Candidate;
+use d_engine_proto::common::NodeRole::Follower;
+use d_engine_proto::common::NodeRole::Leader;
+use d_engine_proto::common::NodeRole::Learner;
+
+pub(crate) fn is_majority(
+    num: usize,
+    total: usize,
+) -> bool {
+    num > (total / 2)
+}
+
+pub fn majority_count(total_nodes: usize) -> usize {
+    (total_nodes / 2) + 1
+}
+
+/// Format error logging
+pub fn error(
+    func_name: &str,
+    e: &dyn std::fmt::Debug,
+) {
+    error!("{}::{} failed: {:?}", module_path!(), func_name, e);
+}
+
+#[inline]
+pub fn is_follower(role_i32: i32) -> bool {
+    role_i32 == Follower.into()
+}
+
+#[inline]
+pub fn is_candidate(role_i32: i32) -> bool {
+    role_i32 == Candidate.into()
+}
+
+#[inline]
+pub fn is_leader(role_i32: i32) -> bool {
+    role_i32 == Leader.into()
+}
+
+#[inline]
+pub fn is_learner(role_i32: i32) -> bool {
+    role_i32 == Learner.into()
+}
diff --git a/src/utils/convert.rs b/d-engine-core/src/utils/convert.rs
similarity index 84%
rename from src/utils/convert.rs
rename to d-engine-core/src/utils/convert.rs
index ad86a04a..9c69d8e2 100644
--- a/src/utils/convert.rs
+++ b/d-engine-core/src/utils/convert.rs
@@ -1,10 +1,9 @@
+use bytes::Bytes;
+use prost::Message;
 use std::hash::DefaultHasher;
 use std::hash::Hash;
 use std::hash::Hasher;
 
-use bytes::Bytes;
-use prost::Message;
-
 use crate::ConvertError;
 use crate::Result;
 
@@ -27,8 +26,8 @@ pub fn safe_kv_bytes(key: u64) -> Bytes {
 /// Converts a `u64` to an 8-byte array in big-endian byte order.
 ///
 /// # Examples
-/// ```
-/// use d_engine::convert::safe_kv;
+/// ```rust
+/// use d_engine_core::convert::safe_kv;
 ///
 /// let bytes = safe_kv(0x1234_5678_9ABC_DEF0);
 /// assert_eq!(bytes, [0x12, 0x34, 0x56, 0x78, 0x9A, 0xBC, 0xDE, 0xF0]);
@@ -52,18 +51,6 @@ pub fn skv(name: String) -> Vec<u8> {
     name.encode_to_vec()
 }
 
-/// return (high, low)
-pub(crate) fn convert_u128_to_u64_with_high_and_low(n: u128) -> (u64, u64) {
-    ((n >> 64) as u64, n as u64)
-}
-/// return (high, low)
-pub(crate) fn convert_high_and_low_fromu64_to_u128(
-    high: u64,
-    low: u64,
-) -> u128 {
-    ((high as u128) << 64) | (low as u128)
-}
-
 /// abs_ceil(0.3) = 1
 /// abs_ceil(0.5) = 1
 /// abs_ceil(1.1) = 2
diff --git a/src/utils/convert_test.rs b/d-engine-core/src/utils/convert_test.rs
similarity index 71%
rename from src/utils/convert_test.rs
rename to d-engine-core/src/utils/convert_test.rs
index 87a2c063..faf128ff 100644
--- a/src/utils/convert_test.rs
+++ b/d-engine-core/src/utils/convert_test.rs
@@ -2,8 +2,6 @@ use std::fmt;
 
 use crate::convert::abs_ceil;
 use crate::convert::classify_error;
-use crate::convert::convert_high_and_low_fromu64_to_u128;
-use crate::convert::convert_u128_to_u64_with_high_and_low;
 use crate::convert::safe_kv;
 use crate::convert::safe_kv_bytes;
 use crate::convert::skv;
@@ -61,42 +59,6 @@ fn test_skv() {
     assert!(!result.is_empty());
 }
 
-#[test]
-fn test_convert_u128_to_u64_with_high_and_low() {
-    // Test basic conversion
-    let n: u128 = 0x1234_5678_9ABC_DEF0_0987_6543_21FE_DCBA;
-    let (high, low) = convert_u128_to_u64_with_high_and_low(n);
-    assert_eq!(high, 0x1234_5678_9ABC_DEF0);
-    assert_eq!(low, 0x0987_6543_21FE_DCBA);
-
-    // Test zero
-    let (high, low) = convert_u128_to_u64_with_high_and_low(0);
-    assert_eq!(high, 0);
-    assert_eq!(low, 0);
-
-    // Test max value
-    let (high, low) = convert_u128_to_u64_with_high_and_low(u128::MAX);
-    assert_eq!(high, u64::MAX);
-    assert_eq!(low, u64::MAX);
-}
-
-#[test]
-fn test_convert_high_and_low_fromu64_to_u128() {
-    // Test basic conversion
-    let high: u64 = 0x1234_5678_9ABC_DEF0;
-    let low: u64 = 0x0987_6543_21FE_DCBA;
-    let result = convert_high_and_low_fromu64_to_u128(high, low);
-    assert_eq!(result, 0x1234_5678_9ABC_DEF0_0987_6543_21FE_DCBA);
-
-    // Test zero
-    let result = convert_high_and_low_fromu64_to_u128(0, 0);
-    assert_eq!(result, 0);
-
-    // Test max values
-    let result = convert_high_and_low_fromu64_to_u128(u64::MAX, u64::MAX);
-    assert_eq!(result, u128::MAX);
-}
-
 #[test]
 fn test_abs_ceil() {
     // Test basic cases
diff --git a/src/utils/file_io.rs b/d-engine-core/src/utils/file_io.rs
similarity index 75%
rename from src/utils/file_io.rs
rename to d-engine-core/src/utils/file_io.rs
index aa762e0f..d7050325 100644
--- a/src/utils/file_io.rs
+++ b/d-engine-core/src/utils/file_io.rs
@@ -1,6 +1,5 @@
-use std::fs::create_dir_all;
 use std::fs::OpenOptions;
-use std::io::ErrorKind;
+use std::fs::create_dir_all;
 use std::io::Read;
 use std::path::Path;
 use std::path::PathBuf;
@@ -62,7 +61,8 @@ pub fn open_file_for_append(path: PathBuf) -> Result<std::fs::File> {
     Ok(log_file)
 }
 
-pub(crate) async fn write_into_file(
+#[allow(dead_code)]
+pub async fn write_into_file(
     path: PathBuf,
     buf: Vec<u8>,
 ) {
@@ -92,7 +92,8 @@ pub(crate) async fn write_into_file(
 ///
 /// # Error
 /// Returns a custom FileError error type, including various possible failure scenarios
-pub(crate) async fn delete_file<P: AsRef<Path>>(path: P) -> Result<()> {
+#[allow(dead_code)]
+pub async fn delete_file<P: AsRef<Path>>(path: P) -> Result<()> {
     let path = path.as_ref();
     let display_path = path.display().to_string();
 
@@ -198,7 +199,7 @@ pub fn validate_checksum(
 ///
 /// # Example
 /// ```rust
-/// use d_engine::file_io::convert_vec_checksum;
+/// use d_engine_core::file_io::convert_vec_checksum;
 ///
 /// let vec_checksum = vec![0u8; 32];
 /// let array_checksum = convert_vec_checksum(vec_checksum).unwrap();
@@ -225,80 +226,6 @@ pub fn convert_vec_checksum(checksum: Vec<u8>) -> Result<[u8; 32]> {
     }
 }
 
-pub(crate) async fn move_directory(
-    temp_dir: &PathBuf,
-    final_dir: &PathBuf,
-) -> Result<()> {
-    // Check if final_dir already exists
-    if fs::metadata(final_dir).await.is_ok() {
-        return Err(StorageError::PathError {
-            path: final_dir.to_path_buf(),
-            source: std::io::Error::new(ErrorKind::AlreadyExists, "Target directory exists"),
-        }
-        .into());
-    }
-
-    // Attempt to rename/move the directory
-    fs::rename(&temp_dir, &final_dir).await.map_err(|e| StorageError::PathError {
-        path: temp_dir.to_path_buf(),
-        source: e,
-    })?;
-
-    Ok(())
-}
-
-pub(crate) async fn is_dir(path: &Path) -> Result<bool> {
-    let metadata = fs::metadata(path).await.map_err(StorageError::IoError)?;
-
-    // Check if it's a directory
-    Ok(metadata.is_dir())
-}
-
-/// Computes a SHA-256 checksum for a directory by hashing the contents of its files.
-///
-/// IMPORTANT: Files are processed in lexicographical order by filename. This is critical because:
-/// 1. File system enumeration order (via `read_dir`) is implementation-defined and
-///    non-deterministic
-/// 2. SHA-256 is order-sensitive: `hash(fileA + fileB) ≠ hash(fileB + fileA)`
-///
-/// The algorithm:
-/// 1. Collects all top-level files in the directory (ignores subdirectories and symlinks)
-/// 2. Sorts files by filename to ensure consistent processing order
-/// 3. Reads each file's content in sorted order
-/// 4. Updates hasher with each file's bytes sequentially
-/// 5. Finalizes and returns the SHA-256 hash
-///
-/// Notes:
-/// - Non-files (directories/symlinks) are silently ignored
-/// - Only top-level files are processed (no recursion into subdirectories)
-/// - File read order is determined by filename sort, not creation time or modification time
-/// - Empty directories will return the SHA-256 hash of empty data
-pub(crate) async fn compute_checksum_from_folder_path(folder_path: &Path) -> Result<[u8; 32]> {
-    let mut hasher = Sha256::new();
-    let mut entries = fs::read_dir(folder_path).await.map_err(StorageError::IoError)?;
-
-    // Collect files while preserving DirEntry information
-    let mut files = Vec::new();
-    while let Some(entry) = entries.next_entry().await.map_err(StorageError::IoError)? {
-        if entry.file_type().await.map_err(StorageError::IoError)?.is_file() {
-            files.push(entry);
-        }
-    }
-
-    // Critical sorting: Filenames compared as OsString but sorted by simple byte order.
-    // This matches lexical order for valid UTF-8 names, and provides consistent ordering
-    // for non-UTF names across platforms.
-    files.sort_by_key(|entry| entry.file_name());
-
-    // Process files in deterministic sorted order
-    for entry in files {
-        let data = fs::read(entry.path()).await.map_err(StorageError::IoError)?;
-        hasher.update(data);
-    }
-
-    Ok(hasher.finalize().into())
-}
-
 /// Computes a SHA-256 checksum for a file by hashing its contents.
 ///
 /// The algorithm:
@@ -311,7 +238,8 @@ pub(crate) async fn compute_checksum_from_folder_path(folder_path: &Path) -> Res
 /// - Processes the entire file content sequentially
 /// - Uses buffered reading to handle large files efficiently
 /// - Consistent across platforms and file systems
-pub(crate) async fn compute_checksum_from_file_path(file_path: &Path) -> Result<[u8; 32]> {
+#[allow(dead_code)]
+pub async fn compute_checksum_from_file_path(file_path: &Path) -> Result<[u8; 32]> {
     let mut file = tokio::fs::File::open(file_path).await.map_err(StorageError::IoError)?;
 
     let mut hasher = Sha256::new();
@@ -366,3 +294,11 @@ pub(crate) fn validate_compressed_format(path: &Path) -> Result<()> {
 
     Ok(())
 }
+
+#[allow(dead_code)]
+pub(super) async fn is_dir(path: &Path) -> Result<bool> {
+    let metadata = fs::metadata(path).await.map_err(StorageError::IoError)?;
+
+    // Check if it's a directory
+    Ok(metadata.is_dir())
+}
diff --git a/src/utils/file_io_test.rs b/d-engine-core/src/utils/file_io_test.rs
similarity index 73%
rename from src/utils/file_io_test.rs
rename to d-engine-core/src/utils/file_io_test.rs
index 5db35d38..1dd579db 100644
--- a/src/utils/file_io_test.rs
+++ b/d-engine-core/src/utils/file_io_test.rs
@@ -1,24 +1,22 @@
 use std::io::Write;
 use std::os::fd::AsRawFd;
 
-use nix::libc::flock;
 use nix::libc::LOCK_EX;
+use nix::libc::flock;
 use sha2::Digest;
 use sha2::Sha256;
-use tempfile::tempdir;
 use tempfile::NamedTempFile;
+use tempfile::tempdir;
 use tracing_test::traced_test;
 
-use crate::file_io;
-use crate::file_io::compute_checksum_from_folder_path;
-use crate::file_io::convert_vec_checksum;
-use crate::file_io::create_parent_dir_if_not_exist;
-use crate::file_io::delete_file;
-use crate::file_io::move_directory;
 use crate::Error;
 use crate::FileError;
 use crate::StorageError;
 use crate::SystemError;
+use crate::file_io;
+use crate::file_io::convert_vec_checksum;
+use crate::file_io::create_parent_dir_if_not_exist;
+use crate::file_io::delete_file;
 
 /// Passed: "/tmp/files/data.txt"
 /// Expected: "/tmp/files" created
@@ -225,25 +223,6 @@ async fn test_delete_permission_denied() {
     fs::set_permissions(&dir_path, perms).await.unwrap();
 }
 
-#[tokio::test]
-#[traced_test]
-async fn test_move_directory() {
-    let temp_dir = tempfile::tempdir().unwrap();
-    let temp_path = temp_dir.path().join("test_move_directory");
-
-    // Old directory path with trailing separator
-    let old_path = temp_path.join("old").join("a").join("b").join(""); // Mark as directory
-    create_parent_dir_if_not_exist(&old_path).unwrap();
-    assert!(file_io::is_dir(&old_path).await.unwrap());
-
-    // New directory
-    let new_path = temp_path.join("new");
-    move_directory(&old_path, &new_path).await.unwrap();
-
-    // Verify new directory exists and old is removed
-    assert!(file_io::is_dir(&new_path).await.unwrap());
-    assert!(!old_path.exists());
-}
 #[test]
 fn test_convert_vec_checksum_converts_valid_checksum() {
     let input = vec![1; 32];
@@ -290,8 +269,8 @@ mod validate_compressed_format_tests {
     use tracing::trace;
 
     use super::*;
-    use crate::file_io::validate_compressed_format;
     use crate::Result;
+    use crate::file_io::validate_compressed_format;
 
     /// Test valid GZIP files with supported extensions
     #[tokio::test]
@@ -401,148 +380,6 @@ mod validate_compressed_format_tests {
     }
 }
 
-#[cfg(test)]
-mod compute_checksum_from_folder_path_tests {
-
-    use super::*;
-
-    /// Test computing checksum for an empty directory
-    #[tokio::test]
-    async fn test_compute_checksum_from_path_empty_dir() {
-        let temp_dir = tempdir().unwrap();
-        let checksum = compute_checksum_from_folder_path(temp_dir.path())
-            .await
-            .expect("Should compute checksum for empty dir");
-
-        // SHA-256 hash of empty data
-        let hasher = Sha256::new();
-        let expected: [u8; 32] = hasher.finalize().into();
-
-        assert_eq!(
-            checksum, expected,
-            "Checksum for empty directory should be SHA-256 of empty data"
-        );
-    }
-
-    /// Test computing checksum for a directory with a single file
-    #[tokio::test]
-    async fn test_compute_checksum_from_path_single_file() {
-        let temp_dir = tempdir().unwrap();
-        let file_path = temp_dir.path().join("test.txt");
-        tokio::fs::write(&file_path, b"Hello, world!").await.unwrap();
-
-        let checksum = compute_checksum_from_folder_path(temp_dir.path())
-            .await
-            .expect("Should compute checksum for directory with single file");
-
-        // Calculate expected SHA-256
-        let mut hasher = Sha256::new();
-        hasher.update(b"Hello, world!");
-        let expected: [u8; 32] = hasher.finalize().into();
-
-        assert_eq!(
-            checksum, expected,
-            "Checksum should match SHA-256 of file content"
-        );
-    }
-
-    /// Test computing checksum for a directory with multiple files
-    #[tokio::test]
-    async fn test_compute_checksum_from_path_multiple_files() {
-        let temp_dir = tempdir().unwrap();
-
-        // Create files with different content
-        tokio::fs::write(temp_dir.path().join("file1.txt"), b"Content 1").await.unwrap();
-        tokio::fs::write(temp_dir.path().join("file2.txt"), b"Content 2").await.unwrap();
-        tokio::fs::write(temp_dir.path().join("file3.txt"), b"Content 3").await.unwrap();
-
-        let checksum = compute_checksum_from_folder_path(temp_dir.path())
-            .await
-            .expect("Should compute checksum for directory with multiple files");
-
-        // Calculate expected SHA-256 (concatenated content of all files)
-        let mut hasher = Sha256::new();
-        hasher.update(b"Content 1");
-        hasher.update(b"Content 2");
-        hasher.update(b"Content 3");
-        let expected: [u8; 32] = hasher.finalize().into();
-
-        assert_eq!(
-            checksum, expected,
-            "Checksum should match SHA-256 of concatenated file contents"
-        );
-    }
-
-    /// Test that checksum ignores subdirectories and only processes files
-    #[tokio::test]
-    async fn test_compute_checksum_ignores_subdirectories() {
-        let temp_dir = tempdir().unwrap();
-
-        // Create a file and a subdirectory
-        tokio::fs::write(temp_dir.path().join("file.txt"), b"File content")
-            .await
-            .unwrap();
-        let sub_dir = temp_dir.path().join("subdir");
-        tokio::fs::create_dir(&sub_dir).await.unwrap();
-        tokio::fs::write(sub_dir.join("ignored.txt"), b"Ignored content").await.unwrap();
-
-        let checksum = compute_checksum_from_folder_path(temp_dir.path())
-            .await
-            .expect("Should compute checksum ignoring subdirectories");
-
-        // Calculate expected SHA-256 (only the top-level file)
-        let mut hasher = Sha256::new();
-        hasher.update(b"File content");
-        let expected: [u8; 32] = hasher.finalize().into();
-
-        assert_eq!(
-            checksum, expected,
-            "Checksum should only include top-level files"
-        );
-    }
-
-    /// Test error handling for non-existent directory
-    #[tokio::test]
-    async fn test_compute_checksum_nonexistent_dir() {
-        let temp_dir = tempdir().unwrap();
-        let non_existent_path = temp_dir.path().join("does_not_exist");
-
-        let result = compute_checksum_from_folder_path(&non_existent_path).await;
-
-        assert!(
-            result.is_err(),
-            "Should return error for non-existent directory"
-        );
-        match result.unwrap_err() {
-            Error::System(SystemError::Storage(StorageError::IoError(_))) => {} // Expected
-            other => panic!("Expected IoError, got {other:?}"),
-        }
-    }
-
-    /// Test checksum consistency across multiple runs
-    #[tokio::test]
-    async fn test_compute_checksum_consistency() {
-        let temp_dir = tempdir().unwrap();
-        tokio::fs::write(temp_dir.path().join("data.bin"), b"Consistent data")
-            .await
-            .unwrap();
-
-        // Compute checksum twice
-        let checksum1 = compute_checksum_from_folder_path(temp_dir.path())
-            .await
-            .expect("First computation should succeed");
-
-        let checksum2 = compute_checksum_from_folder_path(temp_dir.path())
-            .await
-            .expect("Second computation should succeed");
-
-        assert_eq!(
-            checksum1, checksum2,
-            "Checksum should be consistent across multiple computations"
-        );
-    }
-}
-
 #[cfg(test)]
 mod compute_checksum_from_file_path_tests {
     use super::*;
diff --git a/d-engine-core/src/utils/mod.rs b/d-engine-core/src/utils/mod.rs
new file mode 100644
index 00000000..aa0f4b85
--- /dev/null
+++ b/d-engine-core/src/utils/mod.rs
@@ -0,0 +1,15 @@
+pub mod cluster;
+pub mod convert;
+pub mod file_io;
+pub mod scoped_timer;
+pub mod stream;
+pub mod time;
+
+#[cfg(test)]
+mod convert_test;
+#[cfg(test)]
+mod file_io_test;
+#[cfg(test)]
+mod stream_test;
+#[cfg(test)]
+mod time_test;
diff --git a/d-engine-core/src/utils/scoped_timer.rs b/d-engine-core/src/utils/scoped_timer.rs
new file mode 100644
index 00000000..d6ee05c3
--- /dev/null
+++ b/d-engine-core/src/utils/scoped_timer.rs
@@ -0,0 +1,23 @@
+use tokio::time::Instant;
+use tracing::debug;
+
+pub struct ScopedTimer {
+    start: Instant,
+    name: &'static str,
+}
+
+impl ScopedTimer {
+    pub fn new(name: &'static str) -> Self {
+        Self {
+            start: Instant::now(),
+            name,
+        }
+    }
+}
+
+impl Drop for ScopedTimer {
+    fn drop(&mut self) {
+        let elapsed = self.start.elapsed();
+        debug!(target: "timing", "[TIMING] {} took {} ms", self.name, elapsed.as_millis());
+    }
+}
diff --git a/src/utils/stream.rs b/d-engine-core/src/utils/stream.rs
similarity index 96%
rename from src/utils/stream.rs
rename to d-engine-core/src/utils/stream.rs
index 3aa6ebcd..2a8bce53 100644
--- a/src/utils/stream.rs
+++ b/d-engine-core/src/utils/stream.rs
@@ -9,8 +9,8 @@ use http_body_util::BodyExt;
 use http_body_util::StreamBody;
 use prost::Message;
 use tokio::sync::mpsc;
-use tokio_stream::wrappers::ReceiverStream;
 use tokio_stream::StreamExt;
+use tokio_stream::wrappers::ReceiverStream;
 use tonic::Code;
 use tonic::Status;
 use tonic::Streaming; // Adjust path as needed
@@ -46,8 +46,14 @@ pub fn encode_varint(
     buf.put_u8(value as u8);
 }
 
+impl<T> Default for GrpcStreamDecoder<T> {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl<T> GrpcStreamDecoder<T> {
-    pub(crate) fn new() -> Self {
+    pub fn new() -> Self {
         GrpcStreamDecoder {
             _marker: PhantomData,
         }
diff --git a/src/utils/stream_test.rs b/d-engine-core/src/utils/stream_test.rs
similarity index 100%
rename from src/utils/stream_test.rs
rename to d-engine-core/src/utils/stream_test.rs
diff --git a/src/utils/time.rs b/d-engine-core/src/utils/time.rs
similarity index 100%
rename from src/utils/time.rs
rename to d-engine-core/src/utils/time.rs
diff --git a/src/utils/time_test.rs b/d-engine-core/src/utils/time_test.rs
similarity index 100%
rename from src/utils/time_test.rs
rename to d-engine-core/src/utils/time_test.rs
index d6e90a5f..eefc339a 100644
--- a/src/utils/time_test.rs
+++ b/d-engine-core/src/utils/time_test.rs
@@ -1,9 +1,9 @@
 use std::thread::sleep;
 
 use crate::time::get_duration_since_epoch;
-use crate::time::get_now_as_u128;
 use crate::time::get_now_as_u32;
 use crate::time::get_now_as_u64;
+use crate::time::get_now_as_u128;
 use crate::time::timestamp_millis;
 
 #[test]
diff --git a/d-engine-docs/Cargo.toml b/d-engine-docs/Cargo.toml
new file mode 100644
index 00000000..7369ae76
--- /dev/null
+++ b/d-engine-docs/Cargo.toml
@@ -0,0 +1,22 @@
+[package]
+name = "d-engine-docs"
+version = "0.2.0"
+edition = "2024"
+authors = ["Joshua Chi <joshokn@gmail.com>"]
+description = "Documentation and guides for d-engine Raft consensus engine"
+homepage = "https://github.com/deventlab/d-engine"
+repository = "https://github.com/deventlab/d-engine"
+license = "MIT OR Apache-2.0"
+keywords = ["raft", "consensus", "documentation"]
+categories = ["documentation"]
+publish = false
+
+[package.metadata.docs.rs]
+all-features = true
+rustdoc-args = ["--cfg", "docsrs"]
+
+[dependencies]
+d-engine-server = { workspace = true }
+
+tokio = { workspace = true }
+tracing = { workspace = true }
diff --git a/src/docs/architecture/election-design.md b/d-engine-docs/src/docs/architecture/election-design.md
similarity index 100%
rename from src/docs/architecture/election-design.md
rename to d-engine-docs/src/docs/architecture/election-design.md
diff --git a/src/docs/architecture/error-handling-design-principles.md b/d-engine-docs/src/docs/architecture/error-handling-design-principles.md
similarity index 100%
rename from src/docs/architecture/error-handling-design-principles.md
rename to d-engine-docs/src/docs/architecture/error-handling-design-principles.md
diff --git a/src/docs/architecture/mod.rs b/d-engine-docs/src/docs/architecture/mod.rs
similarity index 100%
rename from src/docs/architecture/mod.rs
rename to d-engine-docs/src/docs/architecture/mod.rs
diff --git a/src/docs/architecture/new-node-join-architecture.md b/d-engine-docs/src/docs/architecture/new-node-join-architecture.md
similarity index 100%
rename from src/docs/architecture/new-node-join-architecture.md
rename to d-engine-docs/src/docs/architecture/new-node-join-architecture.md
diff --git a/src/docs/architecture/raft-log-persistence-architecture.md b/d-engine-docs/src/docs/architecture/raft-log-persistence-architecture.md
similarity index 100%
rename from src/docs/architecture/raft-log-persistence-architecture.md
rename to d-engine-docs/src/docs/architecture/raft-log-persistence-architecture.md
diff --git a/src/docs/architecture/raft-role.md b/d-engine-docs/src/docs/architecture/raft-role.md
similarity index 100%
rename from src/docs/architecture/raft-role.md
rename to d-engine-docs/src/docs/architecture/raft-role.md
diff --git a/src/docs/architecture/single-responsibility-principle.md b/d-engine-docs/src/docs/architecture/single-responsibility-principle.md
similarity index 83%
rename from src/docs/architecture/single-responsibility-principle.md
rename to d-engine-docs/src/docs/architecture/single-responsibility-principle.md
index 249c36c6..b6434a2b 100644
--- a/src/docs/architecture/single-responsibility-principle.md
+++ b/d-engine-docs/src/docs/architecture/single-responsibility-principle.md
@@ -5,18 +5,17 @@ This project strictly follows the **Single Responsibility Principle (SRP)** to e
 ### **1. Core Design Philosophy**
 
 - **Main Loop Responsibility**:
-    
-    The `main_loop` (in `src/core/raft.rs`) **only orchestrates event routing**. It:
-    
-    1. Listens for events (e.g., RPCs, timers).
-    2. Delegates handling to the **current role** (e.g., `LeaderState`, `FollowerState`).
-    3. Manages role transitions (e.g., `Leader → Follower`).
+
+  The `main_loop` (in `src/core/raft.rs`) **only orchestrates event routing**. It:
+  1. Listens for events (e.g., RPCs, timers).
+  2. Delegates handling to the **current role** (e.g., `LeaderState`, `FollowerState`).
+  3. Manages role transitions (e.g., `Leader → Follower`).
+
 - **Role-Specific Logic**:
-    
-    Each role (`LeaderState`, `FollowerState`, etc.) **owns its state and behavior**. For example:
-    
-    - `LeaderState` handles log replication and heartbeat management.
-    - `FollowerState` processes leader requests and election timeouts.
+
+  Each role (`LeaderState`, `FollowerState`, etc.) **owns its state and behavior**. For example:
+  - `LeaderState` handles log replication and heartbeat management.
+  - `FollowerState` processes leader requests and election timeouts.
 
 ---
 
@@ -120,7 +119,7 @@ impl FollowerState {
 
 The codebase enforces SRP through role-specific modules:
 
-```ignore
+```text
 src/core/raft_role/
 ├── leader_state.rs          # Leader-only logic (e.g., log replication)
 ├── follower_state.rs        # Follower-only logic (e.g., election timeout)
@@ -137,9 +136,9 @@ When extending the project:
 1. **Identify Ownership**: Should the logic belong to a role, the main loop, or a utility module?
 2. **Avoid Hybrid Roles**: Never create a `LeaderFollowerHybridState`. Use role transitions instead.
 3. **Example**: Adding a "Learner" role:
-    - Create `learner_state.rs` with Learner-specific logic.
-    - Update `main_loop` to handle `Role::Learner`.
-    - Add `RoleEvent::BecomeLearner` for transitions.
+   - Create `learner_state.rs` with Learner-specific logic.
+   - Update `main_loop` to handle `Role::Learner`.
+   - Add `RoleEvent::BecomeLearner` for transitions.
 
 ---
 
@@ -149,4 +148,4 @@ When extending the project:
 - **Safer Changes**: Modifying `FollowerState` won’t accidentally break `LeaderState`.
 - **Protocol Compliance**: Raft requires strict role separation; SRP enforces this naturally.
 
-By following these rules, your contributions will align with the project’s design philosophy.
\ No newline at end of file
+By following these rules, your contributions will align with the project’s design philosophy.
diff --git a/src/docs/architecture/snapshot-module-design.md b/d-engine-docs/src/docs/architecture/snapshot-module-design.md
similarity index 86%
rename from src/docs/architecture/snapshot-module-design.md
rename to d-engine-docs/src/docs/architecture/snapshot-module-design.md
index 75ae212a..198e7347 100644
--- a/src/docs/architecture/snapshot-module-design.md
+++ b/d-engine-docs/src/docs/architecture/snapshot-module-design.md
@@ -171,23 +171,23 @@ if config.max_bandwidth_mbps > 0 {
 
 #### Generating a new snapshot:
 
-1. [**StateMachine**] Generate new DB based on the temporary file provided by the [**StateMachineHandler**] →
-2. [**StateMachine**] Generate data →
-3. [**StateMachine**] Dump current DB into the new DB →
-4. [**StateMachineHandler**] Verify policy conditions and finalize the snapshot and updating the snapshot version.
+1. \[**StateMachine**\] Generate new DB based on the temporary file provided by the \[**StateMachineHandler**\] →
+2. \[**StateMachine**\] Generate data →
+3. \[**StateMachine**\] Dump current DB into the new DB →
+4. \[**StateMachineHandler**\] Verify policy conditions and finalize the snapshot and updating the snapshot version.
 
 #### Applying a snapshot:
 
-1. [**StateMachineHandler**] Snapshot chunk reception and validation →
-2. [**StateMachineHandler**] Write chunks into a temporary file until success →
-3. [**StateMachineHandler**] Error handling and sends error response back to the sender and terminates the process →
-4. After all chunks have been successfully processed and validated, the [**StateMachineHandler**] finalizes the snapshot →
-5. [**StateMachineHandler**] Passing the snapshot file to the [**StateMachine**] →
-6. [**StateMachine**] Apply Snapshot and do online replacement - replacing the old state with the new one based on the snapshot.
+1. \[**StateMachineHandler**\] Snapshot chunk reception and validation →
+2. \[**StateMachineHandler**\] Write chunks into a temporary file until success →
+3. \[**StateMachineHandler**\] Error handling and sends error response back to the sender and terminates the process →
+4. After all chunks have been successfully processed and validated, the \[**StateMachineHandler**\] finalizes the snapshot →
+5. \[**StateMachineHandler**\] Passing the snapshot file to the \[**StateMachine**\] →
+6. \[**StateMachine**\] Apply Snapshot and do online replacement - replacing the old state with the new one based on the snapshot.
 
 #### Cleaning up old snapshots:
 
-[**StateMachineHandler**] automatically maintains old snapshots according to version policies, while the **StateMachine** is not aware of it.
+\[**StateMachineHandler**\] automatically maintains old snapshots according to version policies, while the **StateMachine** is not aware of it.
 
 ## **Purge Log Design**
 
diff --git a/src/docs/client_guide/mod.rs b/d-engine-docs/src/docs/client_guide/mod.rs
similarity index 100%
rename from src/docs/client_guide/mod.rs
rename to d-engine-docs/src/docs/client_guide/mod.rs
diff --git a/src/docs/client_guide/read_consistency.md b/d-engine-docs/src/docs/client_guide/read_consistency.md
similarity index 100%
rename from src/docs/client_guide/read_consistency.md
rename to d-engine-docs/src/docs/client_guide/read_consistency.md
diff --git a/src/docs/mod.rs b/d-engine-docs/src/docs/mod.rs
similarity index 100%
rename from src/docs/mod.rs
rename to d-engine-docs/src/docs/mod.rs
diff --git a/src/docs/overview.md b/d-engine-docs/src/docs/overview.md
similarity index 96%
rename from src/docs/overview.md
rename to d-engine-docs/src/docs/overview.md
index 1e771cf7..914d5fe3 100644
--- a/src/docs/overview.md
+++ b/d-engine-docs/src/docs/overview.md
@@ -24,10 +24,10 @@
 
 ## Quick Start
 
-```no_run
-use d_engine::NodeBuilder;
-use d_engine::FileStorageEngine;
-use d_engine::FileStateMachine;
+```ignore
+use d_engine_server::NodeBuilder;
+use d_engine_server::FileStorageEngine;
+use d_engine_server::FileStateMachine;
 use tokio::sync::watch;
 use tracing::error;
 use tracing::info;
diff --git a/src/docs/performance/mod.rs b/d-engine-docs/src/docs/performance/mod.rs
similarity index 100%
rename from src/docs/performance/mod.rs
rename to d-engine-docs/src/docs/performance/mod.rs
diff --git a/src/docs/performance/throughput-optimization-guide.md b/d-engine-docs/src/docs/performance/throughput-optimization-guide.md
similarity index 100%
rename from src/docs/performance/throughput-optimization-guide.md
rename to d-engine-docs/src/docs/performance/throughput-optimization-guide.md
diff --git a/src/docs/quick-start-5min.md b/d-engine-docs/src/docs/quick-start-5min.md
similarity index 100%
rename from src/docs/quick-start-5min.md
rename to d-engine-docs/src/docs/quick-start-5min.md
diff --git a/src/docs/server_guide/customize-raft-log-purge-executor.md b/d-engine-docs/src/docs/server_guide/customize-raft-log-purge-executor.md
similarity index 100%
rename from src/docs/server_guide/customize-raft-log-purge-executor.md
rename to d-engine-docs/src/docs/server_guide/customize-raft-log-purge-executor.md
diff --git a/src/docs/server_guide/customize-state-machine.md b/d-engine-docs/src/docs/server_guide/customize-state-machine.md
similarity index 100%
rename from src/docs/server_guide/customize-state-machine.md
rename to d-engine-docs/src/docs/server_guide/customize-state-machine.md
diff --git a/src/docs/server_guide/customize-storage-engine.md b/d-engine-docs/src/docs/server_guide/customize-storage-engine.md
similarity index 100%
rename from src/docs/server_guide/customize-storage-engine.md
rename to d-engine-docs/src/docs/server_guide/customize-storage-engine.md
diff --git a/src/docs/server_guide/mod.rs b/d-engine-docs/src/docs/server_guide/mod.rs
similarity index 100%
rename from src/docs/server_guide/mod.rs
rename to d-engine-docs/src/docs/server_guide/mod.rs
diff --git a/d-engine-docs/src/lib.rs b/d-engine-docs/src/lib.rs
new file mode 100644
index 00000000..233e223d
--- /dev/null
+++ b/d-engine-docs/src/lib.rs
@@ -0,0 +1,278 @@
+#![warn(missing_docs)]
+
+//! # d-engine - A Lightweight Raft Consensus Engine
+//!
+//! Welcome to d-engine, a robust, production-ready Raft consensus engine written in Rust.
+//!
+//! ## Overview
+//!
+//! d-engine provides a battle-tested Raft implementation for building distributed systems with:
+//! - **Fault tolerance**: Automatic leader election and recovery
+//! - **Strong consistency**: Ensures all replicas are identical
+//! - **Modularity**: Pluggable storage, state machines, and networking
+//! - **Performance**: Optimized for throughput and latency
+//!
+//! ## Crate Organization
+//!
+//! The d-engine workspace consists of multiple specialized crates:
+//!
+//! | Crate | Purpose | Use Case |
+//! |-------|---------|----------|
+//! | **d-engine-proto** | Protocol definitions using Prost | Shared protocol between components |
+//! | **d-engine-core** | Core Raft algorithm & traits | Understanding Raft consensus logic |
+//! | **d-engine-client** | Client library for applications | Building client applications |
+//! | **d-engine-server** | Server runtime implementation | Running d-engine nodes |
+//! | **d-engine-docs** | Guides, tutorials, and architecture | Learning and reference |
+//!
+//! ## Quick Start: 5 Minutes
+//!
+//! ### Running a Cluster
+//!
+//! ```bash
+//! # Terminal 1: Start first node
+//! cargo run --example three-nodes-cluster -- --node-id 1 --port 9000
+//!
+//! # Terminal 2: Start second node
+//! cargo run --example three-nodes-cluster -- --node-id 2 --port 9001
+//!
+//! # Terminal 3: Start third node
+//! cargo run --example three-nodes-cluster -- --node-id 3 --port 9002
+//! ```
+//!
+//! ### Using the Client
+//!
+//! ```ignore
+//! use d_engine_client::ClientBuilder;
+//!
+//! #[tokio::main]
+//! async fn main() -> Result<(), Box<dyn std::error::Error>> {
+//!     // Create a client
+//!     let client = ClientBuilder::new()
+//!         .endpoints(vec!["http://127.0.0.1:9000".to_string()])
+//!         .build()
+//!         .await?;
+//!
+//!     // Perform operations
+//!     client.put(b"key", b"value").await?;
+//!     let value = client.get(b"key").await?;
+//!     println!("Value: {:?}", value);
+//!
+//!     Ok(())
+//! }
+//! ```
+//!
+//! ## API Documentation
+//!
+//! ### For Server Operators
+//!
+//! - **[d_engine_server API](../d_engine_server/index.html)** - Server runtime and node management
+//!   - How to [customize storage engines](./docs/server_guide/customize-storage-engine.html)
+//!   - How to [implement state machines](./docs/server_guide/customize-state-machine.html)
+//!   - [Performance tuning guide](./docs/performance/throughput-optimization-guide.html)
+//!
+//! ### For Client Developers
+//!
+//! - **[d_engine_client API](../d_engine_client/index.html)** - Client library for applications
+//!   - [Read consistency policies](./docs/client_guide/read_consistency.html)
+//!   - Error handling and retry strategies
+//!   - Connection pooling and timeouts
+//!
+//! ### For System Designers
+//!
+//! - **[d_engine_core API](../d_engine_core/index.html)** - Core Raft implementation
+//!   - Understanding trait-based design
+//!   - Custom storage backend development
+//!   - State machine implementation guide
+//!
+//! ## Architecture Documentation
+//!
+//! Deep dive into d-engine's design and implementation:
+//!
+//! - [Raft Roles and State Transitions](./docs/architecture/raft-role.html)
+//!   - How leader, candidate, and follower states work
+//! - [Election Design](./docs/architecture/election-design.html)
+//!   - Why randomized timeouts prevent split-brain
+//! - [Raft Log Persistence Architecture](./docs/architecture/raft-log-persistence-architecture.html)
+//!   - How log entries are persisted and recovered
+//! - [Snapshot Module Design](./docs/architecture/snapshot-module-design.html)
+//!   - Snapshots for recovery optimization
+//! - [New Node Join Architecture](./docs/architecture/new-node-join-architecture.html)
+//!   - Dynamic cluster membership changes
+//! - [Error Handling Design Principles](./docs/architecture/error-handling-design-principles.html)
+//!   - How errors are categorized and handled
+//! - [Single Responsibility Principle](./docs/architecture/single-responsibility-principle.html)
+//!   - Design philosophy behind modularity
+//!
+//! ## Key Concepts
+//!
+//! ### Raft Protocol Basics
+//!
+//! Raft solves the consensus problem: keeping distributed systems in sync despite failures.
+//!
+//! **Three roles**:
+//! - **Leader**: Accepts client requests and replicates logs
+//! - **Candidate**: Competing to become leader (during elections)
+//! - **Follower**: Replicates leader's logs
+//!
+//! **Key mechanisms**:
+//! - **Log replication**: Leader sends entries to followers sequentially
+//! - **Election**: When leader fails, followers start election with randomized timeouts
+//! - **Snapshots**: Periodic snapshots reduce recovery time
+//! - **Joint consensus**: Safe configuration changes using overlapping quorums
+//!
+//! ### Read Consistency
+//!
+//! d-engine supports different consistency levels:
+//! - **Strong consistency**: Read from leader only (guarantees latest value)
+//! - **Eventual consistency**: Read from any replica (may be stale)
+//!
+//! See [consistency policies guide](./docs/client_guide/read_consistency.html) for details.
+//!
+//! ### Storage Abstraction
+//!
+//! Pluggable backends support different requirements:
+//! - **File-based storage**: Simple, local-only persistence
+//! - **RocksDB**: High-performance embedded database
+//! - **Custom storage**: Implement `LogStore` + `StateSnapshot` traits
+//!
+//! ## Common Patterns
+//!
+//! ### Implementing a Custom Storage Engine
+//!
+//! See [Customize Storage Engine guide](./docs/server_guide/customize-storage-engine.html) for:
+//! - Trait requirements
+//! - Persistence guarantees
+//! - Concurrency considerations
+//!
+//! ### Implementing a Custom State Machine
+//!
+//! See [Customize State Machine guide](./docs/server_guide/customize-state-machine.html) for:
+//! - Processing write commands
+//! - Snapshot serialization
+//! - Recovery from snapshots
+//!
+//! ### Configuring Log Purging
+//!
+//! See [Log Purge Executor guide](./docs/server_guide/customize-raft-log-purge-executor.html) for:
+//! - Automatic log cleanup
+//! - Retention policies
+//! - Performance impact
+//!
+//! ## Performance
+//!
+//! d-engine is optimized for:
+//! - **Throughput**: Batching and pipelining for high request rates
+//! - **Latency**: Single-digit millisecond write latencies
+//! - **Scalability**: Efficient leader-based replication
+//!
+//! See [Performance Tuning Guide](./docs/performance/throughput-optimization-guide.html) for:
+//! - Configuration recommendations
+//! - Benchmarking methodology
+//! - Common bottlenecks and solutions
+//!
+//! ## Building Documentation
+//!
+//! ### Generate All Workspace Documentation
+//!
+//! ```bash
+//! # Generate all crate docs (recommended)
+//! cargo doc --workspace --no-deps --open
+//!
+//! # With all features enabled
+//! cargo doc --workspace --all-features --no-deps --open
+//!
+//! # Include private items (for architecture understanding)
+//! cargo doc --workspace --no-deps --document-private-items --open
+//! ```
+//!
+//! ### Generate Specific Crate Documentation
+//!
+//! ```bash
+//! # Server crate only
+//! cargo doc -p d-engine-server --no-deps --open
+//!
+//! # Client crate only
+//! cargo doc -p d-engine-client --no-deps --open
+//!
+//! # Core Raft implementation
+//! cargo doc -p d-engine-core --no-deps --open
+//! ```
+//!
+//! ### Using Makefile Commands
+//!
+//! ```bash
+//! make docs          # Build documentation
+//! make docs-open     # Build and open in browser
+//! make docs-check    # Verify docs compile without warnings
+//! ```
+//!
+//! ## Examples
+//!
+//! The `examples/` directory contains complete, runnable examples:
+//!
+//! - **three-nodes-cluster**: Basic 3-node cluster setup
+//! - **sled-cluster**: Using Sled embedded database for storage
+//! - **rocksdb-cluster**: Using RocksDB for storage
+//! - **client_usage**: Complete client application example
+//!
+//! Run any example:
+//! ```bash
+//! cargo run --example three-nodes-cluster -- --node-id 1 --port 9000
+//! ```
+//!
+//! ## Testing
+//!
+//! d-engine includes comprehensive tests:
+//!
+//! ```bash
+//! # Run all tests
+//! cargo test --workspace
+//!
+//! # Run tests for specific crate
+//! cargo test -p d-engine-server
+//!
+//! # Run with output
+//! cargo test --workspace -- --nocapture
+//!
+//! # Run integration tests
+//! cargo test --test '*' --workspace
+//! ```
+//!
+//! ## Troubleshooting
+//!
+//! ### Common Issues
+//!
+//! **Q: Cluster won't form**
+//! - Ensure all nodes have different IDs
+//! - Check network connectivity between nodes
+//! - Verify ports are not in use
+//!
+//! **Q: High latency**
+//! - Check network latency between nodes
+//! - Verify storage I/O performance
+//! - Consider batching multiple requests
+//!
+//! **Q: Memory usage growing**
+//! - Check log purging is configured
+//! - Verify snapshots are being taken
+//! - Monitor state machine memory
+//!
+//! See [architecture documentation](./docs/architecture/index.html) for deeper understanding.
+//!
+//! ## Contributing
+//!
+//! Contributions welcome! Areas of interest:
+//! - Performance optimizations
+//! - Additional storage backends
+//! - Protocol improvements
+//! - Documentation and examples
+//!
+//! ## License
+//!
+//! Licensed under either of:
+//! - Apache License, Version 2.0 (LICENSE-APACHE or <http://www.apache.org/licenses/LICENSE-2.0>)
+//! - MIT license (LICENSE-MIT or <http://opensource.org/licenses/MIT>)
+//!
+//! at your option.
+
+pub mod docs;
diff --git a/d-engine-proto/Cargo.toml b/d-engine-proto/Cargo.toml
new file mode 100644
index 00000000..1fff816f
--- /dev/null
+++ b/d-engine-proto/Cargo.toml
@@ -0,0 +1,29 @@
+[package]
+name = "d-engine-proto"
+version = "0.2.0"
+edition = "2021"
+authors = ["Joshua Chi <joshokn@gmail.com>"]
+description = "Protocol definitions and message types for d-engine using Prost"
+homepage = "https://github.com/deventlab/d-engine"
+repository = "https://github.com/deventlab/d-engine"
+license = "MIT OR Apache-2.0"
+keywords = ["raft", "protobuf", "grpc"]
+categories = ["encoding", "network-programming"]
+publish = false
+
+[package.metadata.docs.rs]
+all-features = true
+rustdoc-args = ["--cfg", "docsrs"]
+
+[dependencies]
+# prost = { workspace = true }
+prost = { version = "0.13", features = ["derive"] }
+tonic = { workspace = true }
+serde = { workspace = true }
+bytes = { workspace = true }
+tracing = { workspace = true }
+
+
+[build-dependencies]
+tonic-build = "0.12"
+vergen = { version = "8.1", features = ["git", "gitcl"] }
diff --git a/build.rs b/d-engine-proto/build.rs
similarity index 73%
rename from build.rs
rename to d-engine-proto/build.rs
index cd584fea..a7d1cf3c 100644
--- a/build.rs
+++ b/d-engine-proto/build.rs
@@ -8,11 +8,11 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
             &[
                 "proto/common.proto",
                 "proto/error.proto",
-                "proto/raft_election.proto",
-                "proto/raft_replication.proto",
-                "proto/cluster_management.proto",
-                "proto/storage.proto",
-                "proto/client_api.proto",
+                "proto/server/election.proto",
+                "proto/server/replication.proto",
+                "proto/server/cluster.proto",
+                "proto/server/storage.proto",
+                "proto/client/client_api.proto",
             ],
             &["."],
         )
diff --git a/proto/client_api.proto b/d-engine-proto/proto/client/client_api.proto
similarity index 95%
rename from proto/client_api.proto
rename to d-engine-proto/proto/client/client_api.proto
index f3b18dd4..fd0af951 100644
--- a/proto/client_api.proto
+++ b/d-engine-proto/proto/client/client_api.proto
@@ -1,5 +1,5 @@
 syntax = "proto3";
-package raft.client;
+package d_engine.client;
 
 import "proto/error.proto";
 
@@ -65,14 +65,14 @@ message ClientReadRequest {
 }
 
 message ClientResponse {
-    error.ErrorCode error = 1;
+    d_engine.error.ErrorCode error = 1;
 
     oneof success_result {
         bool write_ack = 2;
         ReadResults read_data = 3;
     }
 
-    error.ErrorMetadata metadata = 4;
+    d_engine.error.ErrorMetadata metadata = 4;
 }
 
 message ClientResult {  // Renamed from ClientGetResult
diff --git a/proto/common.proto b/d-engine-proto/proto/common.proto
similarity index 94%
rename from proto/common.proto
rename to d-engine-proto/proto/common.proto
index 58f144ea..ddad4732 100644
--- a/proto/common.proto
+++ b/d-engine-proto/proto/common.proto
@@ -1,5 +1,5 @@
 syntax = "proto3";
-package raft.common;
+package d_engine.common;
 
 // Basic definitions shared across modules
 message LogId {
@@ -95,3 +95,11 @@ message Snapshot {
     SnapshotMeta meta = 1;
     repeated SnapshotEntry data = 2;
 }
+
+
+enum NodeRole {
+    FOLLOWER = 0;
+    CANDIDATE = 1;
+    LEADER = 2;
+    LEARNER = 3;
+}
diff --git a/proto/error.proto b/d-engine-proto/proto/error.proto
similarity index 79%
rename from proto/error.proto
rename to d-engine-proto/proto/error.proto
index 26a40ab5..5b6748ec 100644
--- a/proto/error.proto
+++ b/d-engine-proto/proto/error.proto
@@ -1,5 +1,5 @@
 syntax = "proto3";
-package raft.error;
+package d_engine.error;
 
 
 enum ErrorCode {
@@ -9,9 +9,9 @@ enum ErrorCode {
     // ======================
     // Network layer error (1000-1999)
     // ======================
-    CONNECTION_TIMEOUT = 1001; 
+    CONNECTION_TIMEOUT = 1001;
     INVALID_ADDRESS = 1002;
-    LEADER_CHANGED = 1003; 
+    LEADER_CHANGED = 1003;
     JOIN_ERROR = 1004;
 
     // ======================
@@ -23,8 +23,8 @@ enum ErrorCode {
     // ======================
     // Storage layer error (3000-3999)
     // ======================
-    DISK_FULL = 3001; 
-    DATA_CORRUPTION = 3002; 
+    DISK_FULL = 3001;
+    DATA_CORRUPTION = 3002;
     STORAGE_IO_ERROR = 3003;
     STORAGE_PERMISSION_DENIED = 3004;
     KEY_NOT_EXIST = 3005;
@@ -32,20 +32,20 @@ enum ErrorCode {
     // ======================
     // Business logic error (4000-4999)
     // ======================
-    NOT_LEADER = 4001; 
-    STALE_OPERATION = 4002; 
-    INVALID_REQUEST = 4003; 
-    RATE_LIMITED = 4004; 
-    CLUSTER_UNAVAILABLE = 4005; 
+    NOT_LEADER = 4001;
+    STALE_OPERATION = 4002;
+    INVALID_REQUEST = 4003;
+    RATE_LIMITED = 4004;
+    CLUSTER_UNAVAILABLE = 4005;
     PROPOSE_FAILED = 4006;
     TERM_OUTDATED = 4007;
     RETRY_REQUIRED = 4008;
-    
+
     // ======================
     // Unclassified error
     // ======================
     GENERAL = 8888;
-    UNCATEGORIZED = 9999; 
+    UNCATEGORIZED = 9999;
 }
 
 message ErrorMetadata {
@@ -58,4 +58,4 @@ message ErrorMetadata {
 
     // Error details (for debugging only)
     optional string debug_message = 15;
-}
\ No newline at end of file
+}
diff --git a/proto/cluster_management.proto b/d-engine-proto/proto/server/cluster.proto
similarity index 91%
rename from proto/cluster_management.proto
rename to d-engine-proto/proto/server/cluster.proto
index b679b357..cd5ac13a 100644
--- a/proto/cluster_management.proto
+++ b/d-engine-proto/proto/server/cluster.proto
@@ -1,8 +1,8 @@
 syntax = "proto3";
-package raft.cluster;
+package d_engine.server.cluster;
 
 import "proto/common.proto";
-import "proto/storage.proto";
+import "proto/server/storage.proto";
 
 
 //Configuration change request specifies the operation type
@@ -18,7 +18,7 @@ message ClusterConfChangeRequest {
     // value is timestamp by default.
     uint64 version = 3;
 
-    raft.common.MembershipChange change = 4;
+    d_engine.common.MembershipChange change = 4;
   }
 
   message ClusterConfUpdateResponse {
@@ -51,7 +51,7 @@ message NodeMeta {
     uint32 id = 1;
     string address = 2; //"ip:port"
     int32 role = 3;
-    raft.common.NodeStatus status = 4; // Add new status fields (such as active/draining)
+    d_engine.common.NodeStatus status = 4; // Add new status fields (such as active/draining)
 }
 
 // Request from new node to join the cluster
@@ -93,7 +93,7 @@ message JoinResponse {
 
   // If the new node needs to receive a snapshot, this field contains the snapshot metadata
   // If no snapshot is needed, this field is empty
-  optional raft.storage.SnapshotMetadata snapshot_metadata = 5;
+  optional d_engine.server.storage.SnapshotMetadata snapshot_metadata = 5;
 
   // The ID of the current leader (if it exists), the new node can connect to the leader to get the snapshot
   uint32 leader_id = 6;
diff --git a/proto/raft_election.proto b/d-engine-proto/proto/server/election.proto
similarity index 86%
rename from proto/raft_election.proto
rename to d-engine-proto/proto/server/election.proto
index cf2a45ec..8bcfeefc 100644
--- a/proto/raft_election.proto
+++ b/d-engine-proto/proto/server/election.proto
@@ -1,5 +1,5 @@
 syntax = "proto3";
-package raft.election;
+package d_engine.server.election;
 
 message VoteRequest {
   uint64 term = 1;
@@ -16,10 +16,10 @@ message VoteResponse {
 }
 
 message VotedFor {
-  uint32 voted_for_id = 1; 
+  uint32 voted_for_id = 1;
   uint64 voted_for_term = 2;
 }
 
 service RaftElectionService {
   rpc RequestVote (VoteRequest) returns (VoteResponse);
-}
\ No newline at end of file
+}
diff --git a/proto/raft_replication.proto b/d-engine-proto/proto/server/replication.proto
similarity index 84%
rename from proto/raft_replication.proto
rename to d-engine-proto/proto/server/replication.proto
index 1df2ebd8..b2449830 100644
--- a/proto/raft_replication.proto
+++ b/d-engine-proto/proto/server/replication.proto
@@ -1,5 +1,5 @@
 syntax = "proto3";
-package raft.replication;
+package d_engine.server.replication;
 
 import "proto/common.proto";
 
@@ -8,7 +8,7 @@ message AppendEntriesRequest {
   uint32 leaderId = 2;
   uint64 prevLogIndex = 3;
   uint64 prevLogTerm = 4;
-  repeated common.Entry entries = 5;  
+  repeated common.Entry entries = 5;
   uint64 leaderCommitIndex = 6;
 }
 
@@ -23,7 +23,7 @@ message AppendEntriesResponse {
 }
 
 message SuccessResult {
-  raft.common.LogId last_match = 1;
+  d_engine.common.LogId last_match = 1;
 }
 
 message ConflictResult {
@@ -33,4 +33,4 @@ message ConflictResult {
 
 service RaftReplicationService {
   rpc AppendEntries (AppendEntriesRequest) returns (AppendEntriesResponse);
-}
\ No newline at end of file
+}
diff --git a/proto/storage.proto b/d-engine-proto/proto/server/storage.proto
similarity index 86%
rename from proto/storage.proto
rename to d-engine-proto/proto/server/storage.proto
index 7c5c9090..9f1a56b8 100644
--- a/proto/storage.proto
+++ b/d-engine-proto/proto/server/storage.proto
@@ -1,5 +1,5 @@
 syntax = "proto3";
-package raft.storage;
+package d_engine.server.storage;
 
 import "proto/common.proto";
 
@@ -27,7 +27,7 @@ message SnapshotChunk {
 }
 
 message SnapshotMetadata {
-    raft.common.LogId last_included = 1; // The last log index included in the snapshot
+    d_engine.common.LogId last_included = 1; // The last log index included in the snapshot
     bytes checksum = 2;             // SHA-256 checksum// Total number of chunks in this snapshot
 }
 
@@ -41,7 +41,7 @@ message PurgeLogRequest {
     uint64 term = 1;
     uint32 leader_id = 2;
     uint64 leader_commit = 3; // Leader's commit_index (for Peer verification)
-    raft.common.LogId last_included = 4; // Maximum log index that can be deleted
+    d_engine.common.LogId last_included = 4; // Maximum log index that can be deleted
     bytes snapshot_checksum = 5;
 }
 
@@ -49,20 +49,20 @@ message PurgeLogResponse {
     uint32 node_id = 1;
     uint64 term = 2; // Peer's current term (for Leader abdication)
     bool success = 3; // Whether to accept the request (non-asynchronous operation result)
-    raft.common.LogId last_purged = 4; // Peer's current purged position (for Leader update progress)
+    d_engine.common.LogId last_purged = 4; // Peer's current purged position (for Leader update progress)
 }
 
 
 message SnapshotAck {
   // Received chunk sequence number
   uint32 seq = 1;
-  
+
   // Status of this chunk
   ChunkStatus status = 2;
-  
+
   // Next requested chunk (for flow control)
   uint32 next_requested = 3;
-  
+
   enum ChunkStatus {
     ACCEPTED = 0;
     CHECKSUM_MISMATCH = 1;
@@ -81,4 +81,4 @@ service SnapshotService {
 
   // Log compaction request
   rpc PurgeLog(PurgeLogRequest) returns (PurgeLogResponse);
-}
\ No newline at end of file
+}
diff --git a/d-engine-proto/src/exts/client_ext.rs b/d-engine-proto/src/exts/client_ext.rs
new file mode 100644
index 00000000..87c78aa8
--- /dev/null
+++ b/d-engine-proto/src/exts/client_ext.rs
@@ -0,0 +1,170 @@
+//! Extensions for protobuf-generated client types
+//!
+//! This module provides additional methods for protobuf-generated types
+//! that are not automatically generated by the protobuf compiler.
+
+use crate::client::client_response::SuccessResult;
+use crate::client::write_command;
+use crate::client::ClientReadRequest;
+use crate::client::ClientResult;
+use bytes::Bytes;
+
+use crate::client::ClientResponse;
+use crate::client::ReadConsistencyPolicy;
+use crate::client::ReadResults;
+use crate::client::WriteCommand;
+use crate::error::ErrorCode;
+
+impl ClientReadRequest {
+    /// Checks if the consistency_policy field is present in the request
+    ///
+    /// Returns true if the client explicitly specified a consistency policy,
+    /// false if the field is absent (should use server default).
+    pub fn has_consistency_policy(&self) -> bool {
+        self.consistency_policy.is_some()
+    }
+
+    /// Gets the consistency policy value safely
+    ///
+    /// Returns Some(policy) if present, None if field is absent.
+    /// Safer alternative that doesn't panic.
+    pub fn get_consistency_policy(&self) -> Option<ReadConsistencyPolicy> {
+        self.consistency_policy.and_then(|policy_i32| {
+            match policy_i32 {
+                x if x == ReadConsistencyPolicy::LeaseRead as i32 => {
+                    Some(ReadConsistencyPolicy::LeaseRead)
+                }
+                x if x == ReadConsistencyPolicy::LinearizableRead as i32 => {
+                    Some(ReadConsistencyPolicy::LinearizableRead)
+                }
+                _ => None, // Invalid value
+            }
+        })
+    }
+}
+
+impl WriteCommand {
+    /// Create write command for key-value pair
+    ///
+    /// # Parameters
+    /// - `key`: Byte array for storage key
+    /// - `value`: Byte array to be stored
+    pub fn insert(
+        key: impl Into<Bytes>,
+        value: impl Into<Bytes>,
+    ) -> Self {
+        let cmd = write_command::Insert {
+            key: key.into(),
+            value: value.into(),
+        };
+        Self {
+            operation: Some(write_command::Operation::Insert(cmd)),
+        }
+    }
+
+    /// Create deletion command for specified key
+    ///
+    /// # Parameters
+    /// - `key`: Byte array of key to delete
+    pub fn delete(key: impl Into<Bytes>) -> Self {
+        let cmd = write_command::Delete { key: key.into() };
+        Self {
+            operation: Some(write_command::Operation::Delete(cmd)),
+        }
+    }
+}
+
+impl ClientResponse {
+    /// Build success response for write operations
+    ///
+    /// # Returns
+    /// Response with NoError code and write confirmation
+    pub fn write_success() -> Self {
+        Self {
+            error: ErrorCode::Success as i32,
+            success_result: Some(SuccessResult::WriteAck(true)),
+            metadata: None,
+        }
+    }
+
+    /// Check if the write operation was successful
+    ///
+    /// # Returns
+    /// - `true` if the response indicates a successful write operation
+    /// - `false` if the response indicates a failed write operation or is not a write response
+    pub fn is_write_success(&self) -> bool {
+        self.error == ErrorCode::Success as i32
+            && matches!(self.success_result, Some(SuccessResult::WriteAck(true)))
+    }
+
+    /// Build success response for read operations
+    ///
+    /// # Parameters
+    /// - `results`: Vector of retrieved key-value pairs
+    pub fn read_results(results: Vec<ClientResult>) -> Self {
+        Self {
+            error: ErrorCode::Success as i32,
+            success_result: Some(SuccessResult::ReadData(ReadResults { results })),
+            metadata: None,
+        }
+    }
+
+    /// Build generic error response for any operation type
+    ///
+    /// # Parameters
+    /// - `error_code`: Predefined client request error code
+    pub fn client_error(error_code: ErrorCode) -> Self {
+        Self {
+            error: error_code as i32,
+            success_result: None,
+            metadata: None,
+        }
+    }
+
+    /// Check if this response indicates the leader's term is outdated
+    pub fn is_term_outdated(&self) -> bool {
+        ErrorCode::try_from(self.error).map(|e| e.is_term_outdated()).unwrap_or(false)
+    }
+
+    /// Check if this response indicates a quorum timeout or failure to receive majority responses
+    pub fn is_quorum_timeout_or_failure(&self) -> bool {
+        ErrorCode::try_from(self.error)
+            .map(|e| e.is_quorum_timeout_or_failure())
+            .unwrap_or(false)
+    }
+
+    /// Check if this response indicates a failure to receive majority responses
+    pub fn is_propose_failure(&self) -> bool {
+        ErrorCode::try_from(self.error).map(|e| e.is_propose_failure()).unwrap_or(false)
+    }
+
+    /// Check if this response indicates a a retry required
+    pub fn is_retry_required(&self) -> bool {
+        ErrorCode::try_from(self.error).map(|e| e.is_retry_required()).unwrap_or(false)
+    }
+}
+
+impl ErrorCode {
+    /// Check if this error indicates the leader's term is outdated
+    pub fn is_term_outdated(&self) -> bool {
+        matches!(self, ErrorCode::TermOutdated)
+    }
+
+    /// Check if this error indicates a quorum timeout or failure to receive majority responses
+    pub fn is_quorum_timeout_or_failure(&self) -> bool {
+        matches!(
+            self,
+            ErrorCode::ConnectionTimeout | ErrorCode::ProposeFailed | ErrorCode::ClusterUnavailable
+        )
+    }
+
+    /// Check if this error indicates a failure to receive majority responses
+    pub fn is_propose_failure(&self) -> bool {
+        matches!(self, ErrorCode::ProposeFailed)
+    }
+
+    /// Check if this error indicates a retry required
+    pub fn is_retry_required(&self) -> bool {
+        matches!(self, ErrorCode::RetryRequired)
+    }
+}
diff --git a/d-engine-proto/src/exts/client_ext_test.rs b/d-engine-proto/src/exts/client_ext_test.rs
new file mode 100644
index 00000000..e3dc8afc
--- /dev/null
+++ b/d-engine-proto/src/exts/client_ext_test.rs
@@ -0,0 +1,297 @@
+use crate::client::{
+    client_response::SuccessResult, ClientReadRequest, ClientResponse, ClientResult,
+    ReadConsistencyPolicy, WriteCommand,
+};
+use crate::error::ErrorCode;
+use bytes::Bytes;
+
+#[test]
+fn test_client_read_request_has_consistency_policy_false() {
+    let request = ClientReadRequest {
+        client_id: 1,
+        keys: vec![],
+        consistency_policy: None,
+    };
+
+    assert!(!request.has_consistency_policy());
+}
+
+#[test]
+fn test_client_read_request_has_consistency_policy_true() {
+    let request = ClientReadRequest {
+        client_id: 1,
+        keys: vec![],
+        consistency_policy: Some(ReadConsistencyPolicy::LeaseRead as i32),
+    };
+
+    assert!(request.has_consistency_policy());
+}
+
+#[test]
+fn test_client_read_request_get_consistency_policy_none() {
+    let request = ClientReadRequest {
+        client_id: 1,
+        keys: vec![],
+        consistency_policy: None,
+    };
+
+    assert_eq!(request.get_consistency_policy(), None);
+}
+
+#[test]
+fn test_client_read_request_get_consistency_policy_lease_read() {
+    let request = ClientReadRequest {
+        client_id: 1,
+        keys: vec![],
+        consistency_policy: Some(ReadConsistencyPolicy::LeaseRead as i32),
+    };
+
+    assert_eq!(
+        request.get_consistency_policy(),
+        Some(ReadConsistencyPolicy::LeaseRead)
+    );
+}
+
+#[test]
+fn test_client_read_request_get_consistency_policy_linearizable_read() {
+    let request = ClientReadRequest {
+        client_id: 1,
+        keys: vec![],
+        consistency_policy: Some(ReadConsistencyPolicy::LinearizableRead as i32),
+    };
+
+    assert_eq!(
+        request.get_consistency_policy(),
+        Some(ReadConsistencyPolicy::LinearizableRead)
+    );
+}
+
+#[test]
+fn test_client_read_request_get_consistency_policy_invalid() {
+    let request = ClientReadRequest {
+        client_id: 1,
+        keys: vec![],
+        consistency_policy: Some(999), // Invalid value
+    };
+
+    assert_eq!(request.get_consistency_policy(), None);
+}
+
+#[test]
+fn test_write_command_insert_creation() {
+    let key = "test_key";
+    let value = "test_value";
+    let cmd = WriteCommand::insert(key, value);
+
+    match cmd.operation {
+        Some(crate::client::write_command::Operation::Insert(insert_cmd)) => {
+            assert_eq!(insert_cmd.key, Bytes::from("test_key"));
+            assert_eq!(insert_cmd.value, Bytes::from("test_value"));
+        }
+        _ => panic!("Expected Insert operation"),
+    }
+}
+
+#[test]
+fn test_write_command_insert_with_bytes() {
+    let key = Bytes::from("key");
+    let value = Bytes::from("value");
+    let cmd = WriteCommand::insert(key.clone(), value.clone());
+
+    match cmd.operation {
+        Some(crate::client::write_command::Operation::Insert(insert_cmd)) => {
+            assert_eq!(insert_cmd.key, key);
+            assert_eq!(insert_cmd.value, value);
+        }
+        _ => panic!("Expected Insert operation"),
+    }
+}
+
+#[test]
+fn test_write_command_delete_creation() {
+    let key = "delete_key";
+    let cmd = WriteCommand::delete(key);
+
+    match cmd.operation {
+        Some(crate::client::write_command::Operation::Delete(delete_cmd)) => {
+            assert_eq!(delete_cmd.key, Bytes::from("delete_key"));
+        }
+        _ => panic!("Expected Delete operation"),
+    }
+}
+
+#[test]
+fn test_write_command_delete_with_bytes() {
+    let key = Bytes::from("my_key");
+    let cmd = WriteCommand::delete(key.clone());
+
+    match cmd.operation {
+        Some(crate::client::write_command::Operation::Delete(delete_cmd)) => {
+            assert_eq!(delete_cmd.key, key);
+        }
+        _ => panic!("Expected Delete operation"),
+    }
+}
+
+#[test]
+fn test_client_response_write_success() {
+    let response = ClientResponse::write_success();
+
+    assert_eq!(response.error, ErrorCode::Success as i32);
+    assert!(response.success_result.is_some());
+    assert_eq!(response.metadata, None);
+
+    match response.success_result {
+        Some(SuccessResult::WriteAck(true)) => {
+            // Success
+        }
+        _ => panic!("Expected WriteAck success"),
+    }
+}
+
+#[test]
+fn test_client_response_is_write_success() {
+    let response = ClientResponse::write_success();
+    assert!(response.is_write_success());
+}
+
+#[test]
+fn test_client_response_is_write_success_false() {
+    let response = ClientResponse::client_error(ErrorCode::ProposeFailed);
+    assert!(!response.is_write_success());
+}
+
+#[test]
+fn test_client_response_read_results() {
+    let results = vec![
+        ClientResult {
+            key: Bytes::from("key1"),
+            value: Bytes::from("value1"),
+        },
+        ClientResult {
+            key: Bytes::from("key2"),
+            value: Bytes::from("value2"),
+        },
+    ];
+
+    let response = ClientResponse::read_results(results.clone());
+
+    assert_eq!(response.error, ErrorCode::Success as i32);
+    match response.success_result {
+        Some(SuccessResult::ReadData(read_results)) => {
+            assert_eq!(read_results.results.len(), 2);
+            assert_eq!(read_results.results[0].key, Bytes::from("key1"));
+            assert_eq!(read_results.results[0].value, Bytes::from("value1"));
+        }
+        _ => panic!("Expected ReadData success"),
+    }
+}
+
+#[test]
+fn test_client_response_client_error() {
+    let response = ClientResponse::client_error(ErrorCode::ConnectionTimeout);
+
+    assert_eq!(response.error, ErrorCode::ConnectionTimeout as i32);
+    assert_eq!(response.success_result, None);
+    assert_eq!(response.metadata, None);
+}
+
+#[test]
+fn test_client_response_is_term_outdated() {
+    let response = ClientResponse::client_error(ErrorCode::TermOutdated);
+    assert!(response.is_term_outdated());
+}
+
+#[test]
+fn test_client_response_is_term_outdated_false() {
+    let response = ClientResponse::client_error(ErrorCode::ConnectionTimeout);
+    assert!(!response.is_term_outdated());
+}
+
+#[test]
+fn test_client_response_is_quorum_timeout_or_failure() {
+    assert!(
+        ClientResponse::client_error(ErrorCode::ConnectionTimeout).is_quorum_timeout_or_failure()
+    );
+    assert!(ClientResponse::client_error(ErrorCode::ProposeFailed).is_quorum_timeout_or_failure());
+    assert!(
+        ClientResponse::client_error(ErrorCode::ClusterUnavailable).is_quorum_timeout_or_failure()
+    );
+}
+
+#[test]
+fn test_client_response_is_propose_failure() {
+    let response = ClientResponse::client_error(ErrorCode::ProposeFailed);
+    assert!(response.is_propose_failure());
+}
+
+#[test]
+fn test_client_response_is_retry_required() {
+    let response = ClientResponse::client_error(ErrorCode::RetryRequired);
+    assert!(response.is_retry_required());
+}
+
+#[test]
+fn test_error_code_is_term_outdated() {
+    assert!(ErrorCode::TermOutdated.is_term_outdated());
+    assert!(!ErrorCode::Success.is_term_outdated());
+}
+
+#[test]
+fn test_error_code_is_propose_failure() {
+    assert!(ErrorCode::ProposeFailed.is_propose_failure());
+    assert!(!ErrorCode::Success.is_propose_failure());
+}
+
+#[test]
+fn test_error_code_is_retry_required() {
+    assert!(ErrorCode::RetryRequired.is_retry_required());
+    assert!(!ErrorCode::Success.is_retry_required());
+}
+
+#[test]
+fn test_write_command_insert_empty_key_value() {
+    let cmd = WriteCommand::insert("", "");
+
+    match cmd.operation {
+        Some(crate::client::write_command::Operation::Insert(insert_cmd)) => {
+            assert_eq!(insert_cmd.key, Bytes::from(""));
+            assert_eq!(insert_cmd.value, Bytes::from(""));
+        }
+        _ => panic!("Expected Insert operation"),
+    }
+}
+
+#[test]
+fn test_write_command_insert_large_data() {
+    // Create byte vectors directly instead of going through String
+    let large_key = vec![b'a'; 1000];
+    let large_value = vec![b'b'; 10000];
+
+    // Convert to Bytes before passing to insert
+    let cmd = WriteCommand::insert(Bytes::from(large_key), Bytes::from(large_value));
+
+    match cmd.operation {
+        Some(crate::client::write_command::Operation::Insert(insert_cmd)) => {
+            assert_eq!(insert_cmd.key.len(), 1000);
+            assert_eq!(insert_cmd.value.len(), 10000);
+            // Verify the content is correct
+            assert!(insert_cmd.key.iter().all(|&b| b == b'a'));
+            assert!(insert_cmd.value.iter().all(|&b| b == b'b'));
+        }
+        _ => panic!("Expected Insert operation"),
+    }
+}
+
+#[test]
+fn test_client_response_read_results_empty() {
+    let response = ClientResponse::read_results(vec![]);
+
+    assert_eq!(response.error, ErrorCode::Success as i32);
+    match response.success_result {
+        Some(SuccessResult::ReadData(read_results)) => {
+            assert_eq!(read_results.results.len(), 0);
+        }
+        _ => panic!("Expected ReadData success"),
+    }
+}
diff --git a/d-engine-proto/src/exts/cluster_ext.rs b/d-engine-proto/src/exts/cluster_ext.rs
new file mode 100644
index 00000000..a0663c76
--- /dev/null
+++ b/d-engine-proto/src/exts/cluster_ext.rs
@@ -0,0 +1,112 @@
+use crate::{
+    common::NodeStatus, server::cluster::cluster_conf_update_response::ErrorCode,
+    server::cluster::ClusterConfUpdateResponse,
+};
+
+impl ClusterConfUpdateResponse {
+    /// Generate a successful response (full success)
+    pub fn success(
+        node_id: u32,
+        term: u64,
+        version: u64,
+    ) -> Self {
+        Self {
+            id: node_id,
+            term,
+            version,
+            success: true,
+            error_code: ErrorCode::None.into(),
+        }
+    }
+
+    /// Generate a failed response (Stale leader term)
+    pub fn higher_term(
+        node_id: u32,
+        term: u64,
+        version: u64,
+    ) -> Self {
+        Self {
+            id: node_id,
+            term,
+            version,
+            success: false,
+            error_code: ErrorCode::TermOutdated.into(),
+        }
+    }
+
+    /// Generate a failed response (Request sent to non-leader or an out-dated leader)
+    pub fn not_leader(
+        node_id: u32,
+        term: u64,
+        version: u64,
+    ) -> Self {
+        Self {
+            id: node_id,
+            term,
+            version,
+            success: false,
+            error_code: ErrorCode::NotLeader.into(),
+        }
+    }
+
+    /// Generate a failed response (Stale configuration version)
+    pub fn version_conflict(
+        node_id: u32,
+        term: u64,
+        version: u64,
+    ) -> Self {
+        Self {
+            id: node_id,
+            term,
+            version,
+            success: false,
+            error_code: ErrorCode::VersionConflict.into(),
+        }
+    }
+
+    /// Generate a failed response (Malformed change request)
+    #[allow(unused)]
+    pub fn invalid_change(
+        node_id: u32,
+        term: u64,
+        version: u64,
+    ) -> Self {
+        Self {
+            id: node_id,
+            term,
+            version,
+            success: false,
+            error_code: ErrorCode::InvalidChange.into(),
+        }
+    }
+
+    /// Generate a failed response (Server-side processing error)
+    pub fn internal_error(
+        node_id: u32,
+        term: u64,
+        version: u64,
+    ) -> Self {
+        Self {
+            id: node_id,
+            term,
+            version,
+            success: false,
+            error_code: ErrorCode::InternalError.into(),
+        }
+    }
+
+    #[allow(unused)]
+    pub fn is_higher_term(&self) -> bool {
+        self.error_code == <ErrorCode as Into<i32>>::into(ErrorCode::TermOutdated)
+    }
+}
+
+impl NodeStatus {
+    pub fn is_promotable(&self) -> bool {
+        matches!(self, NodeStatus::Syncing)
+    }
+
+    pub fn is_i32_promotable(value: i32) -> bool {
+        matches!(value, v if v == (NodeStatus::Syncing as i32))
+    }
+}
diff --git a/d-engine-proto/src/exts/cluster_ext_test.rs b/d-engine-proto/src/exts/cluster_ext_test.rs
new file mode 100644
index 00000000..12477094
--- /dev/null
+++ b/d-engine-proto/src/exts/cluster_ext_test.rs
@@ -0,0 +1,139 @@
+use crate::common::NodeStatus;
+use crate::server::cluster::{cluster_conf_update_response::ErrorCode, ClusterConfUpdateResponse};
+
+#[test]
+fn test_cluster_conf_update_response_success() {
+    let response = ClusterConfUpdateResponse::success(1, 5, 10);
+
+    assert_eq!(response.id, 1);
+    assert_eq!(response.term, 5);
+    assert_eq!(response.version, 10);
+    assert!(response.success);
+    assert_eq!(response.error_code, ErrorCode::None as i32);
+}
+
+#[test]
+fn test_cluster_conf_update_response_higher_term() {
+    let response = ClusterConfUpdateResponse::higher_term(2, 6, 11);
+
+    assert_eq!(response.id, 2);
+    assert_eq!(response.term, 6);
+    assert_eq!(response.version, 11);
+    assert!(!response.success);
+    assert_eq!(response.error_code, ErrorCode::TermOutdated as i32);
+}
+
+#[test]
+fn test_cluster_conf_update_response_not_leader() {
+    let response = ClusterConfUpdateResponse::not_leader(3, 7, 12);
+
+    assert_eq!(response.id, 3);
+    assert_eq!(response.term, 7);
+    assert_eq!(response.version, 12);
+    assert!(!response.success);
+    assert_eq!(response.error_code, ErrorCode::NotLeader as i32);
+}
+
+#[test]
+fn test_cluster_conf_update_response_version_conflict() {
+    let response = ClusterConfUpdateResponse::version_conflict(4, 8, 13);
+
+    assert_eq!(response.id, 4);
+    assert_eq!(response.term, 8);
+    assert_eq!(response.version, 13);
+    assert!(!response.success);
+    assert_eq!(response.error_code, ErrorCode::VersionConflict as i32);
+}
+
+#[test]
+fn test_cluster_conf_update_response_invalid_change() {
+    let response = ClusterConfUpdateResponse::invalid_change(5, 9, 14);
+
+    assert_eq!(response.id, 5);
+    assert_eq!(response.term, 9);
+    assert_eq!(response.version, 14);
+    assert!(!response.success);
+    assert_eq!(response.error_code, ErrorCode::InvalidChange as i32);
+}
+
+#[test]
+fn test_cluster_conf_update_response_internal_error() {
+    let response = ClusterConfUpdateResponse::internal_error(6, 10, 15);
+
+    assert_eq!(response.id, 6);
+    assert_eq!(response.term, 10);
+    assert_eq!(response.version, 15);
+    assert!(!response.success);
+    assert_eq!(response.error_code, ErrorCode::InternalError as i32);
+}
+
+#[test]
+fn test_cluster_conf_update_response_is_higher_term() {
+    let response = ClusterConfUpdateResponse::higher_term(1, 5, 10);
+    assert!(response.is_higher_term());
+}
+
+#[test]
+fn test_cluster_conf_update_response_is_higher_term_false() {
+    let response = ClusterConfUpdateResponse::success(1, 5, 10);
+    assert!(!response.is_higher_term());
+}
+
+#[test]
+fn test_cluster_conf_update_response_all_error_types() {
+    let success = ClusterConfUpdateResponse::success(1, 1, 1);
+    let higher_term = ClusterConfUpdateResponse::higher_term(2, 2, 2);
+    let not_leader = ClusterConfUpdateResponse::not_leader(3, 3, 3);
+    let version_conflict = ClusterConfUpdateResponse::version_conflict(4, 4, 4);
+    let internal_error = ClusterConfUpdateResponse::internal_error(5, 5, 5);
+
+    assert!(success.success);
+    assert!(!higher_term.success);
+    assert!(!not_leader.success);
+    assert!(!version_conflict.success);
+    assert!(!internal_error.success);
+}
+
+#[test]
+fn test_node_status_is_promotable_syncing() {
+    // Syncing is the only promotable status according to is_promotable implementation
+    assert!(NodeStatus::Syncing.is_promotable());
+}
+
+#[test]
+fn test_node_status_is_promotable_other_variants() {
+    // Other variants should not be promotable
+    assert!(!NodeStatus::Joining.is_promotable());
+    assert!(!NodeStatus::Active.is_promotable());
+    assert!(!NodeStatus::StandBy.is_promotable());
+    assert!(!NodeStatus::Draining.is_promotable());
+}
+
+#[test]
+fn test_node_status_is_i32_promotable() {
+    assert!(NodeStatus::is_i32_promotable(NodeStatus::Syncing as i32));
+    assert!(!NodeStatus::is_i32_promotable(NodeStatus::Joining as i32));
+    assert!(!NodeStatus::is_i32_promotable(NodeStatus::Active as i32));
+    assert!(!NodeStatus::is_i32_promotable(NodeStatus::StandBy as i32));
+    assert!(!NodeStatus::is_i32_promotable(NodeStatus::Draining as i32));
+}
+
+#[test]
+fn test_cluster_conf_update_response_large_values() {
+    let response = ClusterConfUpdateResponse::success(u32::MAX, u64::MAX, u64::MAX);
+
+    assert_eq!(response.id, u32::MAX);
+    assert_eq!(response.term, u64::MAX);
+    assert_eq!(response.version, u64::MAX);
+    assert!(response.success);
+}
+
+#[test]
+fn test_cluster_conf_update_response_zero_values() {
+    let response = ClusterConfUpdateResponse::success(0, 0, 0);
+
+    assert_eq!(response.id, 0);
+    assert_eq!(response.term, 0);
+    assert_eq!(response.version, 0);
+    assert!(response.success);
+}
diff --git a/d-engine-proto/src/exts/common_ext.rs b/d-engine-proto/src/exts/common_ext.rs
new file mode 100644
index 00000000..3c7038ec
--- /dev/null
+++ b/d-engine-proto/src/exts/common_ext.rs
@@ -0,0 +1,52 @@
+use crate::common::{
+    entry_payload::Payload, membership_change::Change, EntryPayload, MembershipChange, Noop,
+};
+use bytes::Bytes;
+
+impl EntryPayload {
+    pub fn command(command: Bytes) -> Self {
+        Self {
+            payload: Some(Payload::Command(command)),
+        }
+    }
+    pub fn noop() -> Self {
+        Self {
+            payload: Some(Payload::Noop(Noop {})),
+        }
+    }
+
+    pub fn config(change: Change) -> Self {
+        Self {
+            payload: Some(Payload::Config(MembershipChange {
+                change: Some(change),
+            })),
+        }
+    }
+
+    pub fn is_config(&self) -> bool {
+        match self.payload {
+            Some(Payload::Command(_)) => false,
+            Some(Payload::Config(_)) => true,
+            Some(Payload::Noop(_)) => false,
+            None => false,
+        }
+    }
+
+    pub fn is_command(&self) -> bool {
+        match self.payload {
+            Some(Payload::Command(_)) => true,
+            Some(Payload::Config(_)) => false,
+            Some(Payload::Noop(_)) => false,
+            None => false,
+        }
+    }
+
+    pub fn is_noop(&self) -> bool {
+        match self.payload {
+            Some(Payload::Command(_)) => false,
+            Some(Payload::Config(_)) => false,
+            Some(Payload::Noop(_)) => true,
+            None => false,
+        }
+    }
+}
diff --git a/d-engine-proto/src/exts/common_ext_test.rs b/d-engine-proto/src/exts/common_ext_test.rs
new file mode 100644
index 00000000..33ac13a6
--- /dev/null
+++ b/d-engine-proto/src/exts/common_ext_test.rs
@@ -0,0 +1,164 @@
+use crate::common::{
+    entry_payload::Payload, membership_change::Change, AddNode, EntryPayload, RemoveNode,
+};
+use bytes::Bytes;
+
+#[test]
+fn test_entry_payload_command_creation() {
+    let command_data = Bytes::from("test_command");
+    let payload = EntryPayload::command(command_data.clone());
+
+    assert!(payload.is_command());
+    assert!(!payload.is_noop());
+    assert!(!payload.is_config());
+
+    match payload.payload {
+        Some(Payload::Command(cmd)) => {
+            assert_eq!(cmd, command_data);
+        }
+        _ => panic!("Expected Command payload"),
+    }
+}
+
+#[test]
+fn test_entry_payload_noop_creation() {
+    let payload = EntryPayload::noop();
+
+    assert!(payload.is_noop());
+    assert!(!payload.is_command());
+    assert!(!payload.is_config());
+
+    match payload.payload {
+        Some(Payload::Noop(_)) => {
+            // Success
+        }
+        _ => panic!("Expected Noop payload"),
+    }
+}
+
+#[test]
+fn test_entry_payload_config_with_add_node() {
+    let add_node = AddNode {
+        node_id: 1,
+        address: "127.0.0.1:5000".to_string(),
+    };
+    let change = Change::AddNode(add_node.clone());
+    let payload = EntryPayload::config(change);
+
+    assert!(payload.is_config());
+    assert!(!payload.is_command());
+    assert!(!payload.is_noop());
+
+    match payload.payload {
+        Some(Payload::Config(config)) => match config.change {
+            Some(Change::AddNode(node)) => {
+                assert_eq!(node.node_id, 1);
+                assert_eq!(node.address, "127.0.0.1:5000");
+            }
+            _ => panic!("Expected AddNode change"),
+        },
+        _ => panic!("Expected Config payload"),
+    }
+}
+
+#[test]
+fn test_entry_payload_config_with_remove_node() {
+    let remove_node = RemoveNode { node_id: 2 };
+    let change = Change::RemoveNode(remove_node);
+    let payload = EntryPayload::config(change);
+
+    assert!(payload.is_config());
+    assert!(!payload.is_command());
+    assert!(!payload.is_noop());
+
+    match payload.payload {
+        Some(Payload::Config(config)) => match config.change {
+            Some(Change::RemoveNode(node)) => {
+                assert_eq!(node.node_id, 2);
+            }
+            _ => panic!("Expected RemoveNode change"),
+        },
+        _ => panic!("Expected Config payload"),
+    }
+}
+
+#[test]
+fn test_entry_payload_empty_payload() {
+    let payload = EntryPayload { payload: None };
+
+    assert!(!payload.is_command());
+    assert!(!payload.is_noop());
+    assert!(!payload.is_config());
+}
+
+#[test]
+fn test_entry_payload_command_with_empty_bytes() {
+    let command_data = Bytes::new();
+    let payload = EntryPayload::command(command_data);
+
+    assert!(payload.is_command());
+    assert!(!payload.is_noop());
+    assert!(!payload.is_config());
+}
+
+#[test]
+fn test_entry_payload_command_with_large_data() {
+    let large_data = Bytes::from(vec![0u8; 10_000]);
+    let payload = EntryPayload::command(large_data.clone());
+
+    assert!(payload.is_command());
+    match payload.payload {
+        Some(Payload::Command(cmd)) => {
+            assert_eq!(cmd.len(), 10_000);
+        }
+        _ => panic!("Expected Command payload"),
+    }
+}
+
+#[test]
+fn test_entry_payload_mutually_exclusive() {
+    let cmd = EntryPayload::command(Bytes::from("data"));
+    assert!(cmd.is_command());
+    assert!(!cmd.is_noop());
+    assert!(!cmd.is_config());
+
+    let noop = EntryPayload::noop();
+    assert!(!noop.is_command());
+    assert!(noop.is_noop());
+    assert!(!noop.is_config());
+
+    let remove_node = RemoveNode { node_id: 1 };
+    let change = Change::RemoveNode(remove_node);
+    let cfg = EntryPayload::config(change);
+    assert!(!cfg.is_command());
+    assert!(!cfg.is_noop());
+    assert!(cfg.is_config());
+}
+
+#[test]
+fn test_entry_payload_command_string() {
+    let command = "set key value";
+    let payload = EntryPayload::command(Bytes::from(command));
+
+    assert!(payload.is_command());
+    match payload.payload {
+        Some(Payload::Command(cmd)) => {
+            assert_eq!(cmd.as_ref(), command.as_bytes());
+        }
+        _ => panic!("Expected Command payload"),
+    }
+}
+
+#[test]
+fn test_entry_payload_command_binary() {
+    let binary_data = vec![0xFF, 0xEE, 0xDD, 0xCC, 0xBB];
+    let payload = EntryPayload::command(Bytes::copy_from_slice(&binary_data));
+
+    assert!(payload.is_command());
+    match payload.payload {
+        Some(Payload::Command(cmd)) => {
+            assert_eq!(cmd.as_ref(), binary_data.as_slice());
+        }
+        _ => panic!("Expected Command payload"),
+    }
+}
diff --git a/d-engine-proto/src/exts/mod.rs b/d-engine-proto/src/exts/mod.rs
new file mode 100644
index 00000000..ab8a6fbb
--- /dev/null
+++ b/d-engine-proto/src/exts/mod.rs
@@ -0,0 +1,22 @@
+//! Protocol buffer type extensions
+//!
+//! This module provides additional trait implementations and helper methods
+//! for protobuf-generated types. While the imports appear unused at the module level,
+//! they are re-exported for use by dependent crates (d-engine-core, d-engine, d-engine-client).
+
+pub mod client_ext;
+pub mod cluster_ext;
+pub mod common_ext;
+pub mod replication_ext;
+pub mod storage_ext;
+
+#[cfg(test)]
+mod client_ext_test;
+#[cfg(test)]
+mod cluster_ext_test;
+#[cfg(test)]
+mod common_ext_test;
+#[cfg(test)]
+mod replication_ext_test;
+#[cfg(test)]
+mod storage_ext_test;
diff --git a/d-engine-proto/src/exts/replication_ext.rs b/d-engine-proto/src/exts/replication_ext.rs
new file mode 100644
index 00000000..f6ced053
--- /dev/null
+++ b/d-engine-proto/src/exts/replication_ext.rs
@@ -0,0 +1,76 @@
+use crate::{
+    common::LogId,
+    server::replication::{
+        append_entries_response, AppendEntriesResponse, ConflictResult, SuccessResult,
+    },
+};
+
+impl AppendEntriesResponse {
+    /// Generate a successful response (full success)
+    pub fn success(
+        node_id: u32,
+        term: u64,
+        last_match: Option<LogId>,
+    ) -> Self {
+        Self {
+            node_id,
+            term,
+            result: Some(append_entries_response::Result::Success(SuccessResult {
+                last_match,
+            })),
+        }
+    }
+
+    /// Generate conflict response (with conflict details)
+    pub fn conflict(
+        node_id: u32,
+        term: u64,
+        conflict_term: Option<u64>,
+        conflict_index: Option<u64>,
+    ) -> Self {
+        Self {
+            node_id,
+            term,
+            result: Some(append_entries_response::Result::Conflict(ConflictResult {
+                conflict_term,
+                conflict_index,
+            })),
+        }
+    }
+
+    /// Generate a conflict response (Higher term found)
+    pub fn higher_term(
+        node_id: u32,
+        term: u64,
+    ) -> Self {
+        Self {
+            node_id,
+            term,
+            result: Some(append_entries_response::Result::HigherTerm(term)),
+        }
+    }
+
+    /// Check if it is a success response
+    pub fn is_success(&self) -> bool {
+        matches!(
+            &self.result,
+            Some(append_entries_response::Result::Success(_))
+        )
+    }
+
+    /// Check if it is a conflict response
+    pub fn is_conflict(&self) -> bool {
+        matches!(
+            &self.result,
+            Some(append_entries_response::Result::Conflict(_conflict))
+        )
+    }
+
+    /// Check if it is a response of a higher Term
+    pub fn is_higher_term(&self) -> bool {
+        matches!(
+            &self.result,
+            Some(append_entries_response::Result::HigherTerm(_))
+        )
+    }
+}
diff --git a/d-engine-proto/src/exts/replication_ext_test.rs b/d-engine-proto/src/exts/replication_ext_test.rs
new file mode 100644
index 00000000..eda53c71
--- /dev/null
+++ b/d-engine-proto/src/exts/replication_ext_test.rs
@@ -0,0 +1,145 @@
+use crate::common::LogId;
+use crate::server::replication::AppendEntriesResponse;
+
+#[test]
+fn test_append_entries_response_success() {
+    let log_id = LogId { term: 5, index: 10 };
+    let response = AppendEntriesResponse::success(1, 5, Some(log_id));
+
+    assert_eq!(response.node_id, 1);
+    assert_eq!(response.term, 5);
+    assert!(response.is_success());
+    assert!(!response.is_conflict());
+    assert!(!response.is_higher_term());
+
+    match &response.result {
+        Some(crate::server::replication::append_entries_response::Result::Success(success)) => {
+            assert_eq!(success.last_match, Some(log_id));
+        }
+        _ => panic!("Expected success result"),
+    }
+}
+
+#[test]
+fn test_append_entries_response_success_without_log_id() {
+    let response = AppendEntriesResponse::success(2, 3, None);
+
+    assert_eq!(response.node_id, 2);
+    assert_eq!(response.term, 3);
+    assert!(response.is_success());
+    assert!(!response.is_conflict());
+    assert!(!response.is_higher_term());
+
+    match &response.result {
+        Some(crate::server::replication::append_entries_response::Result::Success(success)) => {
+            assert_eq!(success.last_match, None);
+        }
+        _ => panic!("Expected success result"),
+    }
+}
+
+#[test]
+fn test_append_entries_response_conflict() {
+    let response = AppendEntriesResponse::conflict(3, 6, Some(4), Some(8));
+
+    assert_eq!(response.node_id, 3);
+    assert_eq!(response.term, 6);
+    assert!(!response.is_success());
+    assert!(response.is_conflict());
+    assert!(!response.is_higher_term());
+
+    match &response.result {
+        Some(crate::server::replication::append_entries_response::Result::Conflict(conflict)) => {
+            assert_eq!(conflict.conflict_term, Some(4));
+            assert_eq!(conflict.conflict_index, Some(8));
+        }
+        _ => panic!("Expected conflict result"),
+    }
+}
+
+#[test]
+fn test_append_entries_response_conflict_without_details() {
+    let response = AppendEntriesResponse::conflict(4, 7, None, None);
+
+    assert_eq!(response.node_id, 4);
+    assert_eq!(response.term, 7);
+    assert!(!response.is_success());
+    assert!(response.is_conflict());
+    assert!(!response.is_higher_term());
+
+    match &response.result {
+        Some(crate::server::replication::append_entries_response::Result::Conflict(conflict)) => {
+            assert_eq!(conflict.conflict_term, None);
+            assert_eq!(conflict.conflict_index, None);
+        }
+        _ => panic!("Expected conflict result"),
+    }
+}
+
+#[test]
+fn test_append_entries_response_higher_term() {
+    let response = AppendEntriesResponse::higher_term(5, 10);
+
+    assert_eq!(response.node_id, 5);
+    assert_eq!(response.term, 10);
+    assert!(!response.is_success());
+    assert!(!response.is_conflict());
+    assert!(response.is_higher_term());
+
+    match &response.result {
+        Some(crate::server::replication::append_entries_response::Result::HigherTerm(term)) => {
+            assert_eq!(*term, 10);
+        }
+        _ => panic!("Expected higher term result"),
+    }
+}
+
+#[test]
+fn test_append_entries_response_mutually_exclusive() {
+    // Test success response
+    let success = AppendEntriesResponse::success(1, 1, None);
+    assert!(success.is_success());
+    assert!(!success.is_conflict());
+    assert!(!success.is_higher_term());
+
+    // Test conflict response
+    let conflict = AppendEntriesResponse::conflict(2, 2, None, None);
+    assert!(!conflict.is_success());
+    assert!(conflict.is_conflict());
+    assert!(!conflict.is_higher_term());
+
+    // Test higher term response
+    let higher = AppendEntriesResponse::higher_term(3, 3);
+    assert!(!higher.is_success());
+    assert!(!higher.is_conflict());
+    assert!(higher.is_higher_term());
+}
+
+#[test]
+fn test_append_entries_response_large_indices() {
+    let log_id = LogId {
+        term: u64::MAX,
+        index: u64::MAX,
+    };
+    let response = AppendEntriesResponse::success(u32::MAX, u64::MAX, Some(log_id));
+
+    assert_eq!(response.node_id, u32::MAX);
+    assert_eq!(response.term, u64::MAX);
+
+    match &response.result {
+        Some(crate::server::replication::append_entries_response::Result::Success(success)) => {
+            assert_eq!(success.last_match.unwrap().term, u64::MAX);
+            assert_eq!(success.last_match.unwrap().index, u64::MAX);
+        }
+        _ => panic!("Expected success result"),
+    }
+}
+
+#[test]
+fn test_append_entries_response_zero_values() {
+    let response = AppendEntriesResponse::success(0, 0, None);
+
+    assert_eq!(response.node_id, 0);
+    assert_eq!(response.term, 0);
+    assert!(response.is_success());
+}
diff --git a/d-engine-proto/src/exts/storage_ext.rs b/d-engine-proto/src/exts/storage_ext.rs
new file mode 100644
index 00000000..70340167
--- /dev/null
+++ b/d-engine-proto/src/exts/storage_ext.rs
@@ -0,0 +1,24 @@
+use std::error::Error;
+
+use bytes::Bytes;
+
+use crate::server::storage::SnapshotMetadata;
+
+impl SnapshotMetadata {
+    pub fn checksum_array(&self) -> Result<[u8; 32], Box<dyn Error>> {
+        if self.checksum.len() == 32 {
+            let mut array = [0u8; 32];
+            array.copy_from_slice(&self.checksum);
+            Ok(array)
+        } else {
+            Err(format!("Invalid checksum length: {}", self.checksum.len()).into())
+        }
+    }
+
+    pub fn set_checksum_array(
+        &mut self,
+        array: [u8; 32],
+    ) {
+        self.checksum = Bytes::copy_from_slice(&array);
+    }
+}
diff --git a/d-engine-proto/src/exts/storage_ext_test.rs b/d-engine-proto/src/exts/storage_ext_test.rs
new file mode 100644
index 00000000..f8aade67
--- /dev/null
+++ b/d-engine-proto/src/exts/storage_ext_test.rs
@@ -0,0 +1,96 @@
+use crate::server::storage::SnapshotMetadata;
+use bytes::Bytes;
+
+#[test]
+fn test_snapshot_metadata_checksum_array_valid() {
+    let checksum = [1u8; 32];
+    let metadata = SnapshotMetadata {
+        checksum: Bytes::copy_from_slice(&checksum),
+        ..Default::default()
+    };
+
+    let result = metadata.checksum_array();
+    assert!(result.is_ok());
+    let array = result.unwrap();
+    assert_eq!(array, checksum);
+}
+
+#[test]
+fn test_snapshot_metadata_checksum_array_invalid_length() {
+    let metadata = SnapshotMetadata {
+        checksum: Bytes::from(vec![1u8; 16]), // Wrong length
+        ..Default::default()
+    };
+
+    let result = metadata.checksum_array();
+    assert!(result.is_err());
+    assert_eq!(
+        result.unwrap_err().to_string(),
+        "Invalid checksum length: 16"
+    );
+}
+
+#[test]
+fn test_snapshot_metadata_checksum_array_empty() {
+    let metadata = SnapshotMetadata {
+        checksum: Bytes::new(),
+        ..Default::default()
+    };
+
+    let result = metadata.checksum_array();
+    assert!(result.is_err());
+    assert_eq!(
+        result.unwrap_err().to_string(),
+        "Invalid checksum length: 0"
+    );
+}
+
+#[test]
+fn test_snapshot_metadata_set_checksum_array() {
+    let mut metadata = SnapshotMetadata::default();
+    let checksum = [42u8; 32];
+
+    metadata.set_checksum_array(checksum);
+
+    assert_eq!(metadata.checksum.as_ref(), &checksum);
+}
+
+#[test]
+fn test_snapshot_metadata_round_trip() {
+    let mut metadata = SnapshotMetadata::default();
+    let original_checksum = [123u8; 32];
+
+    metadata.set_checksum_array(original_checksum);
+    let retrieved = metadata.checksum_array().unwrap();
+
+    assert_eq!(retrieved, original_checksum);
+}
+
+#[test]
+fn test_snapshot_metadata_checksum_too_long() {
+    let metadata = SnapshotMetadata {
+        checksum: Bytes::from(vec![1u8; 64]), // Too long
+        ..Default::default()
+    };
+
+    let result = metadata.checksum_array();
+    assert!(result.is_err());
+    assert_eq!(
+        result.unwrap_err().to_string(),
+        "Invalid checksum length: 64"
+    );
+}
+
+#[test]
+fn test_snapshot_metadata_checksum_with_different_values() {
+    let mut metadata = SnapshotMetadata::default();
+    let checksum: [u8; 32] = std::array::from_fn(|i| (i as u8).wrapping_mul(7));
+
+    metadata.set_checksum_array(checksum);
+    let retrieved = metadata.checksum_array().unwrap();
+
+    assert_eq!(retrieved, checksum);
+    for (i, &value) in retrieved.iter().enumerate() {
+        assert_eq!(value, (i as u8).wrapping_mul(7));
+    }
+}
diff --git a/src/generated/raft.client.rs b/d-engine-proto/src/generated/d_engine.client.rs
similarity index 96%
rename from src/generated/raft.client.rs
rename to d-engine-proto/src/generated/d_engine.client.rs
index 9357a134..db31c0a1 100644
--- a/src/generated/raft.client.rs
+++ b/d-engine-proto/src/generated/d_engine.client.rs
@@ -246,12 +246,15 @@ pub mod raft_client_service_client {
                 })?;
             let codec = tonic::codec::ProstCodec::default();
             let path = http::uri::PathAndQuery::from_static(
-                "/raft.client.RaftClientService/HandleClientWrite",
+                "/d_engine.client.RaftClientService/HandleClientWrite",
             );
             let mut req = request.into_request();
             req.extensions_mut()
                 .insert(
-                    GrpcMethod::new("raft.client.RaftClientService", "HandleClientWrite"),
+                    GrpcMethod::new(
+                        "d_engine.client.RaftClientService",
+                        "HandleClientWrite",
+                    ),
                 );
             self.inner.unary(req, path, codec).await
         }
@@ -269,12 +272,15 @@ pub mod raft_client_service_client {
                 })?;
             let codec = tonic::codec::ProstCodec::default();
             let path = http::uri::PathAndQuery::from_static(
-                "/raft.client.RaftClientService/HandleClientRead",
+                "/d_engine.client.RaftClientService/HandleClientRead",
             );
             let mut req = request.into_request();
             req.extensions_mut()
                 .insert(
-                    GrpcMethod::new("raft.client.RaftClientService", "HandleClientRead"),
+                    GrpcMethod::new(
+                        "d_engine.client.RaftClientService",
+                        "HandleClientRead",
+                    ),
                 );
             self.inner.unary(req, path, codec).await
         }
@@ -378,7 +384,7 @@ pub mod raft_client_service_server {
         }
         fn call(&mut self, req: http::Request<B>) -> Self::Future {
             match req.uri().path() {
-                "/raft.client.RaftClientService/HandleClientWrite" => {
+                "/d_engine.client.RaftClientService/HandleClientWrite" => {
                     #[allow(non_camel_case_types)]
                     struct HandleClientWriteSvc<T: RaftClientService>(pub Arc<T>);
                     impl<
@@ -427,7 +433,7 @@ pub mod raft_client_service_server {
                     };
                     Box::pin(fut)
                 }
-                "/raft.client.RaftClientService/HandleClientRead" => {
+                "/d_engine.client.RaftClientService/HandleClientRead" => {
                     #[allow(non_camel_case_types)]
                     struct HandleClientReadSvc<T: RaftClientService>(pub Arc<T>);
                     impl<
@@ -509,7 +515,7 @@ pub mod raft_client_service_server {
         }
     }
     /// Generated gRPC service name
-    pub const SERVICE_NAME: &str = "raft.client.RaftClientService";
+    pub const SERVICE_NAME: &str = "d_engine.client.RaftClientService";
     impl<T> tonic::server::NamedService for RaftClientServiceServer<T> {
         const NAME: &'static str = SERVICE_NAME;
     }
diff --git a/src/generated/raft.error.rs b/d-engine-proto/src/generated/d_engine.common.error.rs
similarity index 100%
rename from src/generated/raft.error.rs
rename to d-engine-proto/src/generated/d_engine.common.error.rs
diff --git a/src/generated/raft.common.rs b/d-engine-proto/src/generated/d_engine.common.rs
similarity index 85%
rename from src/generated/raft.common.rs
rename to d-engine-proto/src/generated/d_engine.common.rs
index 6454b568..143b5c08 100644
--- a/src/generated/raft.common.rs
+++ b/d-engine-proto/src/generated/d_engine.common.rs
@@ -193,3 +193,36 @@ impl NodeStatus {
         }
     }
 }
+#[derive(serde::Serialize, serde::Deserialize)]
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, PartialOrd, Ord, ::prost::Enumeration)]
+#[repr(i32)]
+pub enum NodeRole {
+    Follower = 0,
+    Candidate = 1,
+    Leader = 2,
+    Learner = 3,
+}
+impl NodeRole {
+    /// String value of the enum field names used in the ProtoBuf definition.
+    ///
+    /// The values are not transformed in any way and thus are considered stable
+    /// (if the ProtoBuf definition does not change) and safe for programmatic use.
+    pub fn as_str_name(&self) -> &'static str {
+        match self {
+            Self::Follower => "FOLLOWER",
+            Self::Candidate => "CANDIDATE",
+            Self::Leader => "LEADER",
+            Self::Learner => "LEARNER",
+        }
+    }
+    /// Creates an enum from field names used in the ProtoBuf definition.
+    pub fn from_str_name(value: &str) -> ::core::option::Option<Self> {
+        match value {
+            "FOLLOWER" => Some(Self::Follower),
+            "CANDIDATE" => Some(Self::Candidate),
+            "LEADER" => Some(Self::Leader),
+            "LEARNER" => Some(Self::Learner),
+            _ => None,
+        }
+    }
+}
diff --git a/d-engine-proto/src/generated/d_engine.error.rs b/d-engine-proto/src/generated/d_engine.error.rs
new file mode 100644
index 00000000..55f2eebe
--- /dev/null
+++ b/d-engine-proto/src/generated/d_engine.error.rs
@@ -0,0 +1,119 @@
+// This file is @generated by prost-build.
+#[derive(serde::Serialize, serde::Deserialize)]
+#[derive(Clone, PartialEq, ::prost::Message)]
+pub struct ErrorMetadata {
+    /// Errors suitable for retry
+    #[prost(uint64, optional, tag = "1")]
+    pub retry_after_ms: ::core::option::Option<u64>,
+    /// Leader change information
+    #[prost(string, optional, tag = "2")]
+    pub leader_id: ::core::option::Option<::prost::alloc::string::String>,
+    #[prost(string, optional, tag = "3")]
+    pub leader_address: ::core::option::Option<::prost::alloc::string::String>,
+    /// Error details (for debugging only)
+    #[prost(string, optional, tag = "15")]
+    pub debug_message: ::core::option::Option<::prost::alloc::string::String>,
+}
+#[derive(serde::Serialize, serde::Deserialize)]
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, PartialOrd, Ord, ::prost::Enumeration)]
+#[repr(i32)]
+pub enum ErrorCode {
+    /// Success status (non-error)
+    Success = 0,
+    /// ======================
+    /// Network layer error (1000-1999)
+    /// ======================
+    ConnectionTimeout = 1001,
+    InvalidAddress = 1002,
+    LeaderChanged = 1003,
+    JoinError = 1004,
+    /// ======================
+    /// Protocol layer error (2000-2999)
+    /// ======================
+    InvalidResponse = 2001,
+    VersionMismatch = 2002,
+    /// ======================
+    /// Storage layer error (3000-3999)
+    /// ======================
+    DiskFull = 3001,
+    DataCorruption = 3002,
+    StorageIoError = 3003,
+    StoragePermissionDenied = 3004,
+    KeyNotExist = 3005,
+    /// ======================
+    /// Business logic error (4000-4999)
+    /// ======================
+    NotLeader = 4001,
+    StaleOperation = 4002,
+    InvalidRequest = 4003,
+    RateLimited = 4004,
+    ClusterUnavailable = 4005,
+    ProposeFailed = 4006,
+    TermOutdated = 4007,
+    RetryRequired = 4008,
+    /// ======================
+    /// Unclassified error
+    /// ======================
+    General = 8888,
+    Uncategorized = 9999,
+}
+impl ErrorCode {
+    /// String value of the enum field names used in the ProtoBuf definition.
+    ///
+    /// The values are not transformed in any way and thus are considered stable
+    /// (if the ProtoBuf definition does not change) and safe for programmatic use.
+    pub fn as_str_name(&self) -> &'static str {
+        match self {
+            Self::Success => "SUCCESS",
+            Self::ConnectionTimeout => "CONNECTION_TIMEOUT",
+            Self::InvalidAddress => "INVALID_ADDRESS",
+            Self::LeaderChanged => "LEADER_CHANGED",
+            Self::JoinError => "JOIN_ERROR",
+            Self::InvalidResponse => "INVALID_RESPONSE",
+            Self::VersionMismatch => "VERSION_MISMATCH",
+            Self::DiskFull => "DISK_FULL",
+            Self::DataCorruption => "DATA_CORRUPTION",
+            Self::StorageIoError => "STORAGE_IO_ERROR",
+            Self::StoragePermissionDenied => "STORAGE_PERMISSION_DENIED",
+            Self::KeyNotExist => "KEY_NOT_EXIST",
+            Self::NotLeader => "NOT_LEADER",
+            Self::StaleOperation => "STALE_OPERATION",
+            Self::InvalidRequest => "INVALID_REQUEST",
+            Self::RateLimited => "RATE_LIMITED",
+            Self::ClusterUnavailable => "CLUSTER_UNAVAILABLE",
+            Self::ProposeFailed => "PROPOSE_FAILED",
+            Self::TermOutdated => "TERM_OUTDATED",
+            Self::RetryRequired => "RETRY_REQUIRED",
+            Self::General => "GENERAL",
+            Self::Uncategorized => "UNCATEGORIZED",
+        }
+    }
+    /// Creates an enum from field names used in the ProtoBuf definition.
+    pub fn from_str_name(value: &str) -> ::core::option::Option<Self> {
+        match value {
+            "SUCCESS" => Some(Self::Success),
+            "CONNECTION_TIMEOUT" => Some(Self::ConnectionTimeout),
+            "INVALID_ADDRESS" => Some(Self::InvalidAddress),
+            "LEADER_CHANGED" => Some(Self::LeaderChanged),
+            "JOIN_ERROR" => Some(Self::JoinError),
+            "INVALID_RESPONSE" => Some(Self::InvalidResponse),
+            "VERSION_MISMATCH" => Some(Self::VersionMismatch),
+            "DISK_FULL" => Some(Self::DiskFull),
+            "DATA_CORRUPTION" => Some(Self::DataCorruption),
+            "STORAGE_IO_ERROR" => Some(Self::StorageIoError),
+            "STORAGE_PERMISSION_DENIED" => Some(Self::StoragePermissionDenied),
+            "KEY_NOT_EXIST" => Some(Self::KeyNotExist),
+            "NOT_LEADER" => Some(Self::NotLeader),
+            "STALE_OPERATION" => Some(Self::StaleOperation),
+            "INVALID_REQUEST" => Some(Self::InvalidRequest),
+            "RATE_LIMITED" => Some(Self::RateLimited),
+            "CLUSTER_UNAVAILABLE" => Some(Self::ClusterUnavailable),
+            "PROPOSE_FAILED" => Some(Self::ProposeFailed),
+            "TERM_OUTDATED" => Some(Self::TermOutdated),
+            "RETRY_REQUIRED" => Some(Self::RetryRequired),
+            "GENERAL" => Some(Self::General),
+            "UNCATEGORIZED" => Some(Self::Uncategorized),
+            _ => None,
+        }
+    }
+}
diff --git a/src/generated/raft.cluster.rs b/d-engine-proto/src/generated/d_engine.server.cluster.rs
similarity index 96%
rename from src/generated/raft.cluster.rs
rename to d-engine-proto/src/generated/d_engine.server.cluster.rs
index a3bfccfd..4e6b2585 100644
--- a/src/generated/raft.cluster.rs
+++ b/d-engine-proto/src/generated/d_engine.server.cluster.rs
@@ -15,7 +15,7 @@ pub struct ClusterConfChangeRequest {
     #[prost(uint64, tag = "3")]
     pub version: u64,
     #[prost(message, optional, tag = "4")]
-    pub change: ::core::option::Option<super::common::MembershipChange>,
+    pub change: ::core::option::Option<super::super::common::MembershipChange>,
 }
 #[derive(serde::Serialize, serde::Deserialize)]
 #[derive(Clone, Copy, PartialEq, ::prost::Message)]
@@ -111,7 +111,7 @@ pub struct NodeMeta {
     #[prost(int32, tag = "3")]
     pub role: i32,
     /// Add new status fields (such as active/draining)
-    #[prost(enumeration = "super::common::NodeStatus", tag = "4")]
+    #[prost(enumeration = "super::super::common::NodeStatus", tag = "4")]
     pub status: i32,
 }
 /// Request from new node to join the cluster
@@ -318,13 +318,13 @@ pub mod cluster_management_service_client {
                 })?;
             let codec = tonic::codec::ProstCodec::default();
             let path = http::uri::PathAndQuery::from_static(
-                "/raft.cluster.ClusterManagementService/UpdateClusterConf",
+                "/d_engine.server.cluster.ClusterManagementService/UpdateClusterConf",
             );
             let mut req = request.into_request();
             req.extensions_mut()
                 .insert(
                     GrpcMethod::new(
-                        "raft.cluster.ClusterManagementService",
+                        "d_engine.server.cluster.ClusterManagementService",
                         "UpdateClusterConf",
                     ),
                 );
@@ -347,13 +347,13 @@ pub mod cluster_management_service_client {
                 })?;
             let codec = tonic::codec::ProstCodec::default();
             let path = http::uri::PathAndQuery::from_static(
-                "/raft.cluster.ClusterManagementService/GetClusterMetadata",
+                "/d_engine.server.cluster.ClusterManagementService/GetClusterMetadata",
             );
             let mut req = request.into_request();
             req.extensions_mut()
                 .insert(
                     GrpcMethod::new(
-                        "raft.cluster.ClusterManagementService",
+                        "d_engine.server.cluster.ClusterManagementService",
                         "GetClusterMetadata",
                     ),
                 );
@@ -374,13 +374,13 @@ pub mod cluster_management_service_client {
                 })?;
             let codec = tonic::codec::ProstCodec::default();
             let path = http::uri::PathAndQuery::from_static(
-                "/raft.cluster.ClusterManagementService/JoinCluster",
+                "/d_engine.server.cluster.ClusterManagementService/JoinCluster",
             );
             let mut req = request.into_request();
             req.extensions_mut()
                 .insert(
                     GrpcMethod::new(
-                        "raft.cluster.ClusterManagementService",
+                        "d_engine.server.cluster.ClusterManagementService",
                         "JoinCluster",
                     ),
                 );
@@ -404,13 +404,13 @@ pub mod cluster_management_service_client {
                 })?;
             let codec = tonic::codec::ProstCodec::default();
             let path = http::uri::PathAndQuery::from_static(
-                "/raft.cluster.ClusterManagementService/DiscoverLeader",
+                "/d_engine.server.cluster.ClusterManagementService/DiscoverLeader",
             );
             let mut req = request.into_request();
             req.extensions_mut()
                 .insert(
                     GrpcMethod::new(
-                        "raft.cluster.ClusterManagementService",
+                        "d_engine.server.cluster.ClusterManagementService",
                         "DiscoverLeader",
                     ),
                 );
@@ -536,7 +536,7 @@ pub mod cluster_management_service_server {
         }
         fn call(&mut self, req: http::Request<B>) -> Self::Future {
             match req.uri().path() {
-                "/raft.cluster.ClusterManagementService/UpdateClusterConf" => {
+                "/d_engine.server.cluster.ClusterManagementService/UpdateClusterConf" => {
                     #[allow(non_camel_case_types)]
                     struct UpdateClusterConfSvc<T: ClusterManagementService>(pub Arc<T>);
                     impl<
@@ -585,7 +585,7 @@ pub mod cluster_management_service_server {
                     };
                     Box::pin(fut)
                 }
-                "/raft.cluster.ClusterManagementService/GetClusterMetadata" => {
+                "/d_engine.server.cluster.ClusterManagementService/GetClusterMetadata" => {
                     #[allow(non_camel_case_types)]
                     struct GetClusterMetadataSvc<T: ClusterManagementService>(
                         pub Arc<T>,
@@ -636,7 +636,7 @@ pub mod cluster_management_service_server {
                     };
                     Box::pin(fut)
                 }
-                "/raft.cluster.ClusterManagementService/JoinCluster" => {
+                "/d_engine.server.cluster.ClusterManagementService/JoinCluster" => {
                     #[allow(non_camel_case_types)]
                     struct JoinClusterSvc<T: ClusterManagementService>(pub Arc<T>);
                     impl<
@@ -685,7 +685,7 @@ pub mod cluster_management_service_server {
                     };
                     Box::pin(fut)
                 }
-                "/raft.cluster.ClusterManagementService/DiscoverLeader" => {
+                "/d_engine.server.cluster.ClusterManagementService/DiscoverLeader" => {
                     #[allow(non_camel_case_types)]
                     struct DiscoverLeaderSvc<T: ClusterManagementService>(pub Arc<T>);
                     impl<
@@ -767,7 +767,7 @@ pub mod cluster_management_service_server {
         }
     }
     /// Generated gRPC service name
-    pub const SERVICE_NAME: &str = "raft.cluster.ClusterManagementService";
+    pub const SERVICE_NAME: &str = "d_engine.server.cluster.ClusterManagementService";
     impl<T> tonic::server::NamedService for ClusterManagementServiceServer<T> {
         const NAME: &'static str = SERVICE_NAME;
     }
diff --git a/src/generated/raft.election.rs b/d-engine-proto/src/generated/d_engine.server.election.rs
similarity index 96%
rename from src/generated/raft.election.rs
rename to d-engine-proto/src/generated/d_engine.server.election.rs
index 27a1c0e1..5e9016b2 100644
--- a/src/generated/raft.election.rs
+++ b/d-engine-proto/src/generated/d_engine.server.election.rs
@@ -136,12 +136,15 @@ pub mod raft_election_service_client {
                 })?;
             let codec = tonic::codec::ProstCodec::default();
             let path = http::uri::PathAndQuery::from_static(
-                "/raft.election.RaftElectionService/RequestVote",
+                "/d_engine.server.election.RaftElectionService/RequestVote",
             );
             let mut req = request.into_request();
             req.extensions_mut()
                 .insert(
-                    GrpcMethod::new("raft.election.RaftElectionService", "RequestVote"),
+                    GrpcMethod::new(
+                        "d_engine.server.election.RaftElectionService",
+                        "RequestVote",
+                    ),
                 );
             self.inner.unary(req, path, codec).await
         }
@@ -241,7 +244,7 @@ pub mod raft_election_service_server {
         }
         fn call(&mut self, req: http::Request<B>) -> Self::Future {
             match req.uri().path() {
-                "/raft.election.RaftElectionService/RequestVote" => {
+                "/d_engine.server.election.RaftElectionService/RequestVote" => {
                     #[allow(non_camel_case_types)]
                     struct RequestVoteSvc<T: RaftElectionService>(pub Arc<T>);
                     impl<
@@ -320,7 +323,7 @@ pub mod raft_election_service_server {
         }
     }
     /// Generated gRPC service name
-    pub const SERVICE_NAME: &str = "raft.election.RaftElectionService";
+    pub const SERVICE_NAME: &str = "d_engine.server.election.RaftElectionService";
     impl<T> tonic::server::NamedService for RaftElectionServiceServer<T> {
         const NAME: &'static str = SERVICE_NAME;
     }
diff --git a/src/generated/raft.replication.rs b/d-engine-proto/src/generated/d_engine.server.replication.rs
similarity index 96%
rename from src/generated/raft.replication.rs
rename to d-engine-proto/src/generated/d_engine.server.replication.rs
index 25c277d2..d9eb6bf3 100644
--- a/src/generated/raft.replication.rs
+++ b/d-engine-proto/src/generated/d_engine.server.replication.rs
@@ -11,7 +11,7 @@ pub struct AppendEntriesRequest {
     #[prost(uint64, tag = "4")]
     pub prev_log_term: u64,
     #[prost(message, repeated, tag = "5")]
-    pub entries: ::prost::alloc::vec::Vec<super::common::Entry>,
+    pub entries: ::prost::alloc::vec::Vec<super::super::common::Entry>,
     #[prost(uint64, tag = "6")]
     pub leader_commit_index: u64,
 }
@@ -42,7 +42,7 @@ pub mod append_entries_response {
 #[derive(Clone, Copy, PartialEq, ::prost::Message)]
 pub struct SuccessResult {
     #[prost(message, optional, tag = "1")]
-    pub last_match: ::core::option::Option<super::common::LogId>,
+    pub last_match: ::core::option::Option<super::super::common::LogId>,
 }
 #[derive(serde::Serialize, serde::Deserialize)]
 #[derive(Clone, Copy, PartialEq, ::prost::Message)]
@@ -162,13 +162,13 @@ pub mod raft_replication_service_client {
                 })?;
             let codec = tonic::codec::ProstCodec::default();
             let path = http::uri::PathAndQuery::from_static(
-                "/raft.replication.RaftReplicationService/AppendEntries",
+                "/d_engine.server.replication.RaftReplicationService/AppendEntries",
             );
             let mut req = request.into_request();
             req.extensions_mut()
                 .insert(
                     GrpcMethod::new(
-                        "raft.replication.RaftReplicationService",
+                        "d_engine.server.replication.RaftReplicationService",
                         "AppendEntries",
                     ),
                 );
@@ -274,7 +274,7 @@ pub mod raft_replication_service_server {
         }
         fn call(&mut self, req: http::Request<B>) -> Self::Future {
             match req.uri().path() {
-                "/raft.replication.RaftReplicationService/AppendEntries" => {
+                "/d_engine.server.replication.RaftReplicationService/AppendEntries" => {
                     #[allow(non_camel_case_types)]
                     struct AppendEntriesSvc<T: RaftReplicationService>(pub Arc<T>);
                     impl<
@@ -356,7 +356,7 @@ pub mod raft_replication_service_server {
         }
     }
     /// Generated gRPC service name
-    pub const SERVICE_NAME: &str = "raft.replication.RaftReplicationService";
+    pub const SERVICE_NAME: &str = "d_engine.server.replication.RaftReplicationService";
     impl<T> tonic::server::NamedService for RaftReplicationServiceServer<T> {
         const NAME: &'static str = SERVICE_NAME;
     }
diff --git a/src/generated/raft.storage.rs b/d-engine-proto/src/generated/d_engine.server.storage.rs
similarity index 94%
rename from src/generated/raft.storage.rs
rename to d-engine-proto/src/generated/d_engine.server.storage.rs
index d6155408..a5f3445d 100644
--- a/src/generated/raft.storage.rs
+++ b/d-engine-proto/src/generated/d_engine.server.storage.rs
@@ -29,7 +29,7 @@ pub struct SnapshotChunk {
 pub struct SnapshotMetadata {
     /// The last log index included in the snapshot
     #[prost(message, optional, tag = "1")]
-    pub last_included: ::core::option::Option<super::common::LogId>,
+    pub last_included: ::core::option::Option<super::super::common::LogId>,
     /// SHA-256 checksum// Total number of chunks in this snapshot
     #[prost(bytes = "bytes", tag = "2")]
     pub checksum: ::prost::bytes::Bytes,
@@ -59,7 +59,7 @@ pub struct PurgeLogRequest {
     pub leader_commit: u64,
     /// Maximum log index that can be deleted
     #[prost(message, optional, tag = "4")]
-    pub last_included: ::core::option::Option<super::common::LogId>,
+    pub last_included: ::core::option::Option<super::super::common::LogId>,
     #[prost(bytes = "bytes", tag = "5")]
     pub snapshot_checksum: ::prost::bytes::Bytes,
 }
@@ -76,7 +76,7 @@ pub struct PurgeLogResponse {
     pub success: bool,
     /// Peer's current purged position (for Leader update progress)
     #[prost(message, optional, tag = "4")]
-    pub last_purged: ::core::option::Option<super::common::LogId>,
+    pub last_purged: ::core::option::Option<super::super::common::LogId>,
 }
 #[derive(serde::Serialize, serde::Deserialize)]
 #[derive(Clone, Copy, PartialEq, ::prost::Message)]
@@ -249,12 +249,15 @@ pub mod snapshot_service_client {
                 })?;
             let codec = tonic::codec::ProstCodec::default();
             let path = http::uri::PathAndQuery::from_static(
-                "/raft.storage.SnapshotService/InstallSnapshot",
+                "/d_engine.server.storage.SnapshotService/InstallSnapshot",
             );
             let mut req = request.into_streaming_request();
             req.extensions_mut()
                 .insert(
-                    GrpcMethod::new("raft.storage.SnapshotService", "InstallSnapshot"),
+                    GrpcMethod::new(
+                        "d_engine.server.storage.SnapshotService",
+                        "InstallSnapshot",
+                    ),
                 );
             self.inner.client_streaming(req, path, codec).await
         }
@@ -276,12 +279,15 @@ pub mod snapshot_service_client {
                 })?;
             let codec = tonic::codec::ProstCodec::default();
             let path = http::uri::PathAndQuery::from_static(
-                "/raft.storage.SnapshotService/StreamSnapshot",
+                "/d_engine.server.storage.SnapshotService/StreamSnapshot",
             );
             let mut req = request.into_streaming_request();
             req.extensions_mut()
                 .insert(
-                    GrpcMethod::new("raft.storage.SnapshotService", "StreamSnapshot"),
+                    GrpcMethod::new(
+                        "d_engine.server.storage.SnapshotService",
+                        "StreamSnapshot",
+                    ),
                 );
             self.inner.streaming(req, path, codec).await
         }
@@ -303,11 +309,16 @@ pub mod snapshot_service_client {
                 })?;
             let codec = tonic::codec::ProstCodec::default();
             let path = http::uri::PathAndQuery::from_static(
-                "/raft.storage.SnapshotService/PurgeLog",
+                "/d_engine.server.storage.SnapshotService/PurgeLog",
             );
             let mut req = request.into_request();
             req.extensions_mut()
-                .insert(GrpcMethod::new("raft.storage.SnapshotService", "PurgeLog"));
+                .insert(
+                    GrpcMethod::new(
+                        "d_engine.server.storage.SnapshotService",
+                        "PurgeLog",
+                    ),
+                );
             self.inner.unary(req, path, codec).await
         }
     }
@@ -432,7 +443,7 @@ pub mod snapshot_service_server {
         }
         fn call(&mut self, req: http::Request<B>) -> Self::Future {
             match req.uri().path() {
-                "/raft.storage.SnapshotService/InstallSnapshot" => {
+                "/d_engine.server.storage.SnapshotService/InstallSnapshot" => {
                     #[allow(non_camel_case_types)]
                     struct InstallSnapshotSvc<T: SnapshotService>(pub Arc<T>);
                     impl<
@@ -480,7 +491,7 @@ pub mod snapshot_service_server {
                     };
                     Box::pin(fut)
                 }
-                "/raft.storage.SnapshotService/StreamSnapshot" => {
+                "/d_engine.server.storage.SnapshotService/StreamSnapshot" => {
                     #[allow(non_camel_case_types)]
                     struct StreamSnapshotSvc<T: SnapshotService>(pub Arc<T>);
                     impl<
@@ -527,7 +538,7 @@ pub mod snapshot_service_server {
                     };
                     Box::pin(fut)
                 }
-                "/raft.storage.SnapshotService/PurgeLog" => {
+                "/d_engine.server.storage.SnapshotService/PurgeLog" => {
                     #[allow(non_camel_case_types)]
                     struct PurgeLogSvc<T: SnapshotService>(pub Arc<T>);
                     impl<
@@ -605,7 +616,7 @@ pub mod snapshot_service_server {
         }
     }
     /// Generated gRPC service name
-    pub const SERVICE_NAME: &str = "raft.storage.SnapshotService";
+    pub const SERVICE_NAME: &str = "d_engine.server.storage.SnapshotService";
     impl<T> tonic::server::NamedService for SnapshotServiceServer<T> {
         const NAME: &'static str = SERVICE_NAME;
     }
diff --git a/d-engine-proto/src/lib.rs b/d-engine-proto/src/lib.rs
new file mode 100644
index 00000000..f8068e77
--- /dev/null
+++ b/d-engine-proto/src/lib.rs
@@ -0,0 +1,36 @@
+//! Protocol buffer type extensions
+//!
+//! This module provides additional trait implementations and helper methods
+//! for protobuf-generated types. The re-exports here are used by dependent crates
+//! (d-engine-core, d-engine, d-engine-client) when they import from this crate.
+
+pub mod common {
+    include!("generated/d_engine.common.rs");
+}
+
+pub mod error {
+    include!("generated/d_engine.common.error.rs");
+}
+pub mod server {
+    pub mod cluster {
+        include!("generated/d_engine.server.cluster.rs");
+    }
+
+    pub mod replication {
+        include!("generated/d_engine.server.replication.rs");
+    }
+
+    pub mod election {
+        include!("generated/d_engine.server.election.rs");
+    }
+
+    pub mod storage {
+        include!("generated/d_engine.server.storage.rs");
+    }
+}
+
+pub mod client {
+    include!("generated/d_engine.client.rs");
+}
+
+pub mod exts;
diff --git a/d-engine-server/Cargo.toml b/d-engine-server/Cargo.toml
new file mode 100644
index 00000000..9a69e5cd
--- /dev/null
+++ b/d-engine-server/Cargo.toml
@@ -0,0 +1,68 @@
+[package]
+name = "d-engine-server"
+version = "0.2.0"
+edition = "2024"
+authors = ["Joshua Chi <joshokn@gmail.com>"]
+description = "Production-ready Raft consensus engine server and runtime"
+homepage = "https://github.com/deventlab/d-engine"
+repository = "https://github.com/deventlab/d-engine"
+license = "MIT OR Apache-2.0"
+keywords = ["raft", "consensus", "distributed-systems", "async"]
+categories = ["asynchronous", "concurrency", "network-programming"]
+publish = false
+
+[package.metadata.docs.rs]
+all-features = true
+rustdoc-args = ["--cfg", "docsrs"]
+
+[features]
+test-utils = ["mockall", "tokio-tar", "async-compression", "nanoid"]
+rocksdb = ["dep:rocksdb"]
+
+[dependencies]
+d-engine-proto = { workspace = true }
+d-engine-core = { workspace = true }
+
+tokio = { workspace = true }
+tonic = { workspace = true }
+bytes =  { workspace = true }
+serde = { workspace = true }
+tracing = { workspace = true }
+tempfile = { workspace = true }
+futures = { workspace = true }
+prost = { workspace = true }
+bincode = "1.3"
+rocksdb = { version = "0.24.0", optional = true }
+config = { version = "0.14.0", default-features = false, features = ["toml"] }
+arc-swap = "1.7.1"
+dashmap = "5.5.3"
+# use tokio_util::sync::CancellationToken;
+tokio-util = "0.7.11"
+tokio-stream = "0.1.16"
+# certification
+rcgen = { version = "0.13", features = ["pem"] }
+crc32fast = "1.4.2"
+# used in stream
+http-body = "1.0"
+http-body-util = "0.1.3"
+tonic-health = "0.12.3"
+parking_lot = "0.12.3"
+crossbeam = "0.8"
+crossbeam-skiplist = "0.1"
+mockall = { version = "0.12.1", optional = true }
+nanoid = { version = "0.4.0", optional = true }
+tokio-tar = { version = "0.3", optional = true }
+async-compression = { version = "0.4", features = ["tokio", "gzip"], optional = true}
+
+metrics = { version = "0.24", features = [] }
+
+
+[dev-dependencies]
+d-engine-server = { workspace = true, features = ["test-utils"] }
+d-engine-core = { workspace = true, features = ["test-utils"] }
+serial_test = "3.2.0"
+temp-env = "0.3.6"
+tracing-test = "0.2"
+tokio-stream = "0.1.16"
+uuid = { version = "1", features = ["v4"] }
+tokio = { version = "1", features = ["test-util", "process"] }
diff --git a/d-engine-server/src/lib.rs b/d-engine-server/src/lib.rs
new file mode 100644
index 00000000..9604c2d0
--- /dev/null
+++ b/d-engine-server/src/lib.rs
@@ -0,0 +1,152 @@
+//! # d-engine-server
+//!
+//! Production-ready Raft consensus server implementation.
+//!
+//! ## Architecture
+//! - [`node`] - Node lifecycle management
+//! - [`storage`] - Pluggable storage backends
+//! - Core Raft protocol (re-exported from `d-engine-core`)
+//! - Protocol definitions (re-exported from `d-engine-proto`)
+//!
+//! ## Quick Start
+//! ```ignore
+//! use d_engine_server::{NodeBuilder, FileStorageEngine, FileStateMachine};
+//! use std::sync::Arc;
+//! use std::path::PathBuf;
+//!
+//! #[tokio::main(flavor = "current_thread")]
+//! async fn main() -> Result<(), Box<dyn std::error::Error>> {
+//!     let (tx, rx) = tokio::sync::watch::channel(());
+//!
+//!     let storage = Arc::new(FileStorageEngine::new(PathBuf::from("/tmp/storage"))?);
+//!     let state_machine = Arc::new(FileStateMachine::new(PathBuf::from("/tmp/sm")).await?);
+//!
+//!     let node = NodeBuilder::new(None, rx)
+//!         .storage_engine(storage)
+//!         .state_machine(state_machine)
+//!         .build()
+//!         .start_rpc_server()
+//!         .await
+//!         .ready()?;
+//!
+//!     node.run().await?;
+//!     Ok(())
+//! }
+//! ```
+//!
+//! ## Custom Storage Backend
+//!
+//! Implement the [`StateMachine`] and [`StorageEngine`] traits:
+//!
+//! ```rust,ignore
+//! use d_engine_server::{StateMachine, StorageEngine};
+//!
+//! struct MyStateMachine { /* ... */ }
+//! impl StateMachine for MyStateMachine { /* ... */ }
+//!
+//! struct MyStorageEngine { /* ... */ }
+//! impl StorageEngine for MyStorageEngine { /* ... */ }
+//! ```
+//!
+//! See the [d-engine-docs](https://docs.rs/d-engine-docs) for architecture details.
+
+#![doc = include_str!("../../d-engine-docs/src/docs/overview.md")]
+#![warn(missing_docs)]
+
+// ==================== Core Public API ====================
+
+/// Node lifecycle management
+///
+/// Contains [`Node`] and [`NodeBuilder`] for server setup.
+pub mod node;
+
+/// Storage layer implementations
+///
+/// Provides file-based and RocksDB storage backends.
+pub mod storage;
+
+// -------------------- Primary Entry Points --------------------
+pub use node::{Node, NodeBuilder};
+
+// Re-export storage implementations
+pub use storage::{
+    FileStateMachine,
+    // File-based storage
+    FileStorageEngine,
+};
+
+// Conditional RocksDB exports
+#[cfg(feature = "rocksdb")]
+pub use storage::{RocksDBStateMachine, RocksDBStorageEngine};
+
+// -------------------- Extension Traits --------------------
+
+/// Storage trait for implementing custom storage backends
+///
+/// Implement this trait to create your own storage engine.
+pub use d_engine_core::{StateMachine, StorageEngine};
+
+/// Log storage trait
+pub use d_engine_core::LogStore;
+
+/// Metadata storage trait
+pub use d_engine_core::MetaStore;
+
+// -------------------- Error Types --------------------
+
+/// Unified error type for all d-engine operations
+pub use d_engine_core::Error;
+
+/// Unified result type (equivalent to Result<T, Error>)
+pub use d_engine_core::Result;
+
+/// Storage-specific error type
+pub use d_engine_core::StorageError;
+
+/// Snapshot operation error type
+pub use d_engine_core::SnapshotError;
+
+/// Protocol buffer error type
+pub use d_engine_core::ProstError;
+
+/// Hard state (Raft persistent state: term, voted_for, log)
+pub use d_engine_core::HardState;
+
+// -------------------- Data Types --------------------
+
+/// Common Raft protocol types
+pub mod common {
+    // Basic types used in Raft consensus protocol
+    pub use d_engine_proto::common::{Entry, EntryPayload, LogId, entry_payload};
+}
+
+/// Client protocol types
+pub mod client {
+    // Client write command types for custom business logic
+    pub use d_engine_proto::client::{WriteCommand, write_command};
+}
+
+/// Server storage protocol types
+pub mod server_storage {
+    // Server storage protocol types (snapshots, replication)
+    pub use d_engine_proto::server::storage::SnapshotMetadata;
+}
+
+// ==================== Internal API (Hidden) ====================
+mod membership;
+mod network;
+mod utils;
+
+#[doc(hidden)]
+pub use d_engine_core::Raft;
+
+// ==================== Test Utilities ====================
+
+/// Test utilities for d-engine-server
+///
+/// This module is only available when the `test-utils` feature is enabled
+/// or when running tests.
+///
+/// Contains mock implementations and test helpers.
+#[cfg(any(test, feature = "test-utils"))]
+pub mod test_utils;
diff --git a/src/membership/membership_guard.rs b/d-engine-server/src/membership/membership_guard.rs
similarity index 95%
rename from src/membership/membership_guard.rs
rename to d-engine-server/src/membership/membership_guard.rs
index 1cca0697..070ba8f4 100644
--- a/src/membership/membership_guard.rs
+++ b/d-engine-server/src/membership/membership_guard.rs
@@ -5,9 +5,9 @@ use arc_swap::ArcSwap;
 use tokio::sync::Mutex;
 use tracing::info;
 
-use crate::proto::cluster::NodeMeta;
-use crate::MembershipError;
-use crate::Result;
+use d_engine_core::MembershipError;
+use d_engine_core::Result;
+use d_engine_proto::server::cluster::NodeMeta;
 
 pub struct MembershipGuard {
     // Atomic state pointer for lock-free reads
diff --git a/src/membership/membership_guard_test.rs b/d-engine-server/src/membership/membership_guard_test.rs
similarity index 97%
rename from src/membership/membership_guard_test.rs
rename to d-engine-server/src/membership/membership_guard_test.rs
index 3b2b3565..7a140203 100644
--- a/src/membership/membership_guard_test.rs
+++ b/d-engine-server/src/membership/membership_guard_test.rs
@@ -5,10 +5,10 @@ use tokio::sync::oneshot;
 use tracing_test::traced_test;
 
 use super::*;
-use crate::proto::cluster::NodeMeta;
-use crate::ConsensusError;
-use crate::Error;
-use crate::MembershipError;
+use d_engine_core::ConsensusError;
+use d_engine_core::Error;
+use d_engine_core::MembershipError;
+use d_engine_proto::server::cluster::NodeMeta;
 
 fn create_test_node(id: u32) -> NodeMeta {
     NodeMeta {
diff --git a/d-engine-server/src/membership/mod.rs b/d-engine-server/src/membership/mod.rs
new file mode 100644
index 00000000..91052c0d
--- /dev/null
+++ b/d-engine-server/src/membership/mod.rs
@@ -0,0 +1,9 @@
+mod membership_guard;
+mod raft_membership;
+pub(crate) use membership_guard::*;
+pub use raft_membership::*;
+
+#[cfg(test)]
+mod membership_guard_test;
+#[cfg(test)]
+mod raft_membership_test;
diff --git a/src/membership/raft_membership.rs b/d-engine-server/src/membership/raft_membership.rs
similarity index 91%
rename from src/membership/raft_membership.rs
rename to d-engine-server/src/membership/raft_membership.rs
index 20b6afa6..23bc92de 100644
--- a/src/membership/raft_membership.rs
+++ b/d-engine-server/src/membership/raft_membership.rs
@@ -15,42 +15,42 @@
 use std::fmt::Debug;
 use std::marker::PhantomData;
 
-use futures::stream::FuturesUnordered;
+use d_engine_core::ensure_safe_join;
 use futures::FutureExt;
 use futures::StreamExt;
+use futures::stream::FuturesUnordered;
 use tokio::task;
 use tonic::async_trait;
 use tonic::transport::Channel;
 use tracing::debug;
 use tracing::error;
 use tracing::info;
-use tracing::instrument;
 use tracing::warn;
 
 use super::MembershipGuard;
-use crate::async_task::task_with_timeout_and_exponential_backoff;
-use crate::net::address_str;
-use crate::proto::cluster::ClusterConfChangeRequest;
-use crate::proto::cluster::ClusterConfUpdateResponse;
-use crate::proto::cluster::ClusterMembership;
-use crate::proto::cluster::NodeMeta;
-use crate::proto::common::membership_change::Change;
-use crate::proto::common::MembershipChange;
-use crate::proto::common::NodeStatus;
-use crate::ConnectionCache;
-use crate::ConnectionType;
-use crate::HealthChecker;
-use crate::HealthCheckerApis;
-use crate::HealthMonitor;
-use crate::Membership;
-use crate::MembershipError;
-use crate::RaftHealthMonitor;
-use crate::RaftNodeConfig;
-use crate::Result;
-use crate::TypeConfig;
-use crate::FOLLOWER;
-use crate::LEADER;
-use crate::LEARNER;
+use crate::network::ConnectionCache;
+use crate::network::HealthChecker;
+use crate::network::HealthCheckerApis;
+use crate::network::HealthMonitor;
+use crate::network::RaftHealthMonitor;
+use crate::utils::async_task::task_with_timeout_and_exponential_backoff;
+use crate::utils::net::address_str;
+use d_engine_core::ConnectionType;
+use d_engine_core::Membership;
+use d_engine_core::MembershipError;
+use d_engine_core::RaftNodeConfig;
+use d_engine_core::Result;
+use d_engine_core::TypeConfig;
+use d_engine_proto::common::MembershipChange;
+use d_engine_proto::common::NodeRole::Follower;
+use d_engine_proto::common::NodeRole::Leader;
+use d_engine_proto::common::NodeRole::Learner;
+use d_engine_proto::common::NodeStatus;
+use d_engine_proto::common::membership_change::Change;
+use d_engine_proto::server::cluster::ClusterConfChangeRequest;
+use d_engine_proto::server::cluster::ClusterConfUpdateResponse;
+use d_engine_proto::server::cluster::ClusterMembership;
+use d_engine_proto::server::cluster::NodeMeta;
 
 pub struct RaftMembership<T>
 where
@@ -282,15 +282,15 @@ where
         leader_id: u32,
     ) -> Result<()> {
         self.reset_leader().await?;
-        self.update_node_role(leader_id, LEADER).await
+        self.update_node_role(leader_id, Leader.into()).await
     }
 
     async fn reset_leader(&self) -> Result<()> {
         self.membership
             .blocking_write(|guard| {
                 for node in guard.nodes.values_mut() {
-                    if node.role == LEADER {
-                        node.role = FOLLOWER;
+                    if node.role == Leader.into() {
+                        node.role = Follower.into();
                     }
                 }
                 Ok(())
@@ -322,7 +322,7 @@ where
     async fn current_leader_id(&self) -> Option<u32> {
         self.membership
             .blocking_read(|guard| {
-                guard.nodes.values().find(|node| node.role == LEADER).map(|node| node.id)
+                guard.nodes.values().find(|node| node.role == Leader.into()).map(|node| node.id)
             })
             .await
     }
@@ -388,8 +388,8 @@ where
                 }
                 Some(Change::Promote(promote)) => {
                     self.update_single_node(promote.node_id, |node| {
-                        if node.role == LEARNER {
-                            node.role = FOLLOWER;
+                        if node.role == Learner.into() {
+                            node.role = Follower.into();
                             Ok(())
                         } else {
                             Err(MembershipError::InvalidPromotion {
@@ -405,7 +405,7 @@ where
                     self.update_multiple_nodes(&bp.node_ids, |node| {
                         if NodeStatus::is_i32_promotable(node.status) {
                             node.status = bp.new_status;
-                            node.role = FOLLOWER;
+                            node.role = Follower.into();
                         }
                         Ok(())
                     })
@@ -493,7 +493,7 @@ where
                     NodeMeta {
                         id: node_id,
                         address,
-                        role: LEARNER,
+                        role: Learner.into(),
                         status: NodeStatus::Syncing as i32,
                     },
                 );
@@ -673,7 +673,7 @@ where
                             .nodes
                             .get_mut(&promote.node_id)
                             .map(|node| {
-                                node.role = FOLLOWER;
+                                node.role = Follower.into();
                                 node.status = NodeStatus::Active as i32;
                                 Ok(())
                             })
@@ -685,7 +685,7 @@ where
                             })
                     })
                     .await
-                // self.update_node_role(promote.node_id, FOLLOWER).await?;
+                // self.update_node_role(promote.node_id, Follower.into()).await?;
                 // self.update_node_status(promote.node_id, NodeStatus::Active).await
             }
             Some(Change::BatchPromote(bp)) => {
@@ -696,7 +696,7 @@ where
                                 MembershipError::NoMetadataFoundForNode { node_id: *node_id },
                             )?;
 
-                            node.role = FOLLOWER;
+                            node.role = Follower.into();
                             node.status = NodeStatus::try_from(bp.new_status)
                                 .unwrap_or(NodeStatus::Active)
                                 as i32;
@@ -750,7 +750,7 @@ where
         role: i32,
     ) -> Result<()> {
         // New nodes must be learners
-        if role != LEARNER {
+        if role != Learner.into() {
             return Err(MembershipError::NotLearner.into());
         }
 
@@ -769,7 +769,7 @@ impl<T> RaftMembership<T>
 where
     T: TypeConfig,
 {
-    pub fn new(
+    pub(crate) fn new(
         node_id: u32,
         initial_nodes: Vec<NodeMeta>,
         config: RaftNodeConfig,
@@ -842,33 +842,3 @@ where
         .await
     }
 }
-
-#[instrument]
-pub fn ensure_safe_join(
-    node_id: u32,
-    current_voters: usize,
-) -> Result<()> {
-    // Total voters including leader = current_voters + 1
-    let total_voters = current_voters + 1;
-
-    // Always allow if cluster will have even number of voters
-    if (total_voters + 1).is_multiple_of(2) {
-        Ok(())
-    } else {
-        // metrics::counter!("cluster.unsafe_join_attempts", 1);
-        metrics::counter!(
-            "cluster.unsafe_join_attempts",
-            &[("node_id", node_id.to_string())]
-        )
-        .increment(1);
-
-        warn!(
-            "Unsafe join attempt: current_voters={} (total_voters={})",
-            current_voters, total_voters
-        );
-        Err(
-            MembershipError::JoinClusterError("Cluster must maintain odd number of voters".into())
-                .into(),
-        )
-    }
-}
diff --git a/src/membership/raft_membership_test.rs b/d-engine-server/src/membership/raft_membership_test.rs
similarity index 87%
rename from src/membership/raft_membership_test.rs
rename to d-engine-server/src/membership/raft_membership_test.rs
index 19b76ac4..0fc7f169 100644
--- a/src/membership/raft_membership_test.rs
+++ b/d-engine-server/src/membership/raft_membership_test.rs
@@ -1,68 +1,69 @@
+use d_engine_core::MockStateMachine;
 use tokio::sync::oneshot;
 use tracing_test::traced_test;
 
 use super::RaftMembership;
-use crate::ensure_safe_join;
-use crate::proto::cluster::cluster_conf_update_response::ErrorCode;
-use crate::proto::cluster::ClusterConfChangeRequest;
-use crate::proto::cluster::NodeMeta;
-use crate::proto::common::membership_change::Change;
-use crate::proto::common::AddNode;
-use crate::proto::common::BatchRemove;
-use crate::proto::common::MembershipChange;
-use crate::proto::common::NodeStatus;
-use crate::proto::common::PromoteLearner;
-use crate::proto::common::RemoveNode;
-use crate::test_utils::MockNode;
-use crate::test_utils::MockRpcService;
-use crate::test_utils::MockStorageEngine;
-use crate::test_utils::MockTypeConfig;
-use crate::ConnectionType;
-use crate::ConsensusError;
-use crate::Error;
-use crate::Membership;
-use crate::MembershipError;
-use crate::MockStateMachine;
-use crate::RaftNodeConfig;
-use crate::RaftTypeConfig;
-use crate::CANDIDATE;
-use crate::FOLLOWER;
-use crate::LEADER;
-use crate::LEARNER;
+use d_engine_core::ConnectionType;
+use d_engine_core::ConsensusError;
+use d_engine_core::Error;
+
+use crate::node::RaftTypeConfig;
+use d_engine_core::Membership;
+use d_engine_core::MembershipError;
+use d_engine_core::MockStorageEngine;
+use d_engine_core::MockTypeConfig;
+use d_engine_core::RaftNodeConfig;
+use d_engine_core::ensure_safe_join;
+use d_engine_core::test_utils::MockNode;
+use d_engine_core::test_utils::MockRpcService;
+use d_engine_proto::common::AddNode;
+use d_engine_proto::common::BatchRemove;
+use d_engine_proto::common::MembershipChange;
+use d_engine_proto::common::NodeRole::Candidate;
+use d_engine_proto::common::NodeRole::Follower;
+use d_engine_proto::common::NodeRole::Leader;
+use d_engine_proto::common::NodeRole::Learner;
+use d_engine_proto::common::NodeStatus;
+use d_engine_proto::common::PromoteLearner;
+use d_engine_proto::common::RemoveNode;
+use d_engine_proto::common::membership_change::Change;
+use d_engine_proto::server::cluster::ClusterConfChangeRequest;
+use d_engine_proto::server::cluster::NodeMeta;
+use d_engine_proto::server::cluster::cluster_conf_update_response::ErrorCode;
 
 // Helper function to create a test instance
-pub fn create_test_membership(
-) -> RaftMembership<RaftTypeConfig<MockStorageEngine, MockStateMachine>> {
+pub fn create_test_membership()
+-> RaftMembership<RaftTypeConfig<MockStorageEngine, MockStateMachine>> {
     // Prepare cluster membership
     let initial_cluster = vec![
         NodeMeta {
             id: 1,
             address: "127.0.0.1:10000".to_string(),
-            role: LEADER,
+            role: Leader.into(),
             status: NodeStatus::Active.into(),
         },
         NodeMeta {
             id: 2,
             address: "127.0.0.1:10000".to_string(),
-            role: FOLLOWER,
+            role: Follower.into(),
             status: NodeStatus::Active.into(),
         },
         NodeMeta {
             id: 3,
             address: "127.0.0.1:10000".to_string(),
-            role: FOLLOWER,
+            role: Follower.into(),
             status: NodeStatus::Active.into(),
         },
         NodeMeta {
             id: 4,
             address: "127.0.0.1:10000".to_string(),
-            role: LEARNER,
+            role: Learner.into(),
             status: NodeStatus::Joining.into(),
         },
         NodeMeta {
             id: 5,
             address: "127.0.0.1:10000".to_string(),
-            role: LEARNER,
+            role: Learner.into(),
             status: NodeStatus::Joining.into(),
         },
     ];
@@ -181,31 +182,31 @@ async fn test_replication_peers_case1() {
         NodeMeta {
             id: 1,
             address: "127.0.0.1:10000".to_string(),
-            role: LEADER,
+            role: Leader.into(),
             status: NodeStatus::Active.into(),
         },
         NodeMeta {
             id: 2,
             address: "127.0.0.1:10000".to_string(),
-            role: FOLLOWER,
+            role: Follower.into(),
             status: NodeStatus::Active.into(),
         },
         NodeMeta {
             id: 3,
             address: "127.0.0.1:10000".to_string(),
-            role: FOLLOWER,
+            role: Follower.into(),
             status: NodeStatus::Active.into(),
         },
         NodeMeta {
             id: 4,
             address: "127.0.0.1:10000".to_string(),
-            role: LEARNER,
+            role: Learner.into(),
             status: NodeStatus::Syncing.into(),
         },
         NodeMeta {
             id: 5,
             address: "127.0.0.1:10000".to_string(),
-            role: LEARNER,
+            role: Learner.into(),
             status: NodeStatus::Joining.into(),
         },
     ];
@@ -236,31 +237,31 @@ async fn test_mark_leader_id_case1() {
         NodeMeta {
             id: old_leader_id,
             address: "127.0.0.1:10000".to_string(),
-            role: LEADER,
+            role: Leader.into(),
             status: NodeStatus::Active.into(),
         },
         NodeMeta {
             id: 3,
             address: "127.0.0.1:10000".to_string(),
-            role: FOLLOWER,
+            role: Follower.into(),
             status: NodeStatus::Active.into(),
         },
         NodeMeta {
             id: 4,
             address: "127.0.0.1:10000".to_string(),
-            role: LEARNER,
+            role: Learner.into(),
             status: NodeStatus::Active.into(),
         },
         NodeMeta {
             id: 5,
             address: "127.0.0.1:10000".to_string(),
-            role: FOLLOWER,
+            role: Follower.into(),
             status: NodeStatus::Active.into(),
         },
         NodeMeta {
             id: 6,
             address: "127.0.0.1:10000".to_string(),
-            role: LEARNER,
+            role: Learner.into(),
             status: NodeStatus::Active.into(),
         },
     ];
@@ -292,31 +293,31 @@ async fn test_mark_leader_id_case2() {
         NodeMeta {
             id: 1,
             address: "127.0.0.1:10000".to_string(),
-            role: FOLLOWER,
+            role: Follower.into(),
             status: NodeStatus::Active.into(),
         },
         NodeMeta {
             id: 3,
             address: "127.0.0.1:10000".to_string(),
-            role: FOLLOWER,
+            role: Follower.into(),
             status: NodeStatus::Active.into(),
         },
         NodeMeta {
             id: 4,
             address: "127.0.0.1:10000".to_string(),
-            role: LEARNER,
+            role: Learner.into(),
             status: NodeStatus::Active.into(),
         },
         NodeMeta {
             id: 5,
             address: "127.0.0.1:10000".to_string(),
-            role: FOLLOWER,
+            role: Follower.into(),
             status: NodeStatus::Active.into(),
         },
         NodeMeta {
             id: 6,
             address: "127.0.0.1:10000".to_string(),
-            role: LEARNER,
+            role: Learner.into(),
             status: NodeStatus::Active.into(),
         },
     ];
@@ -338,31 +339,31 @@ async fn test_retrieve_cluster_membership_config() {
         NodeMeta {
             id: 1,
             address: "127.0.0.1:10000".to_string(),
-            role: FOLLOWER,
+            role: Follower.into(),
             status: NodeStatus::Active.into(),
         },
         NodeMeta {
             id: 3,
             address: "127.0.0.1:10000".to_string(),
-            role: FOLLOWER,
+            role: Follower.into(),
             status: NodeStatus::Active.into(),
         },
         NodeMeta {
             id: 4,
             address: "127.0.0.1:10000".to_string(),
-            role: LEARNER,
+            role: Learner.into(),
             status: NodeStatus::Active.into(),
         },
         NodeMeta {
             id: 5,
             address: "127.0.0.1:10000".to_string(),
-            role: FOLLOWER,
+            role: Follower.into(),
             status: NodeStatus::Active.into(),
         },
         NodeMeta {
             id: 6,
             address: "127.0.0.1:10000".to_string(),
-            role: LEARNER,
+            role: Learner.into(),
             status: NodeStatus::Active.into(),
         },
     ];
@@ -374,7 +375,7 @@ async fn test_retrieve_cluster_membership_config() {
 
     let r = membership.retrieve_cluster_membership_config().await;
     assert_eq!(r.nodes.len(), 5);
-    assert!(!r.nodes.iter().any(|n| n.role == LEADER));
+    assert!(!r.nodes.iter().any(|n| n.role == Leader.into()));
 }
 
 #[tokio::test]
@@ -394,16 +395,18 @@ async fn test_update_cluster_conf_from_leader_case1() {
         }),
     };
 
-    assert!(membership
-        .update_cluster_conf_from_leader(
-            1,       // my_id
-            1,       // my_current_term
-            0,       // current_conf_version
-            Some(2), // current_leader_id
-            &req,
-        )
-        .await
-        .is_ok());
+    assert!(
+        membership
+            .update_cluster_conf_from_leader(
+                1,       // my_id
+                1,       // my_current_term
+                0,       // current_conf_version
+                Some(2), // current_leader_id
+                &req,
+            )
+            .await
+            .is_ok()
+    );
     assert!(membership.contains_node(3).await);
     assert_eq!(membership.get_cluster_conf_version().await, 0); // Version from request
 }
@@ -417,7 +420,7 @@ async fn test_update_cluster_conf_from_leader_case2() {
         vec![NodeMeta {
             id: 3,
             address: "127.0.0.1:8080".to_string(),
-            role: FOLLOWER,
+            role: Follower.into(),
             status: NodeStatus::Active.into(),
         }],
         RaftNodeConfig::default(),
@@ -431,16 +434,18 @@ async fn test_update_cluster_conf_from_leader_case2() {
         }),
     };
 
-    assert!(membership
-        .update_cluster_conf_from_leader(
-            1,       // my_id
-            1,       // my_current_term
-            0,       // current_conf_version
-            Some(2), // current_leader_id
-            &req,
-        )
-        .await
-        .is_ok());
+    assert!(
+        membership
+            .update_cluster_conf_from_leader(
+                1,       // my_id
+                1,       // my_current_term
+                0,       // current_conf_version
+                Some(2), // current_leader_id
+                &req,
+            )
+            .await
+            .is_ok()
+    );
     assert!(!membership.contains_node(3).await);
     assert_eq!(membership.get_cluster_conf_version().await, 1);
 }
@@ -454,7 +459,7 @@ async fn test_update_cluster_conf_from_leader_case3() {
         vec![NodeMeta {
             id: 3,
             address: "127.0.0.1:8080".to_string(),
-            role: LEARNER,
+            role: Learner.into(),
             status: NodeStatus::Active.into(),
         }],
         RaftNodeConfig::default(),
@@ -483,7 +488,10 @@ async fn test_update_cluster_conf_from_leader_case3() {
         .expect("should succeed");
 
     assert!(response.success);
-    assert_eq!(membership.get_role_by_node_id(3).await.unwrap(), FOLLOWER);
+    assert_eq!(
+        membership.get_role_by_node_id(3).await.unwrap(),
+        Follower.into()
+    );
     assert_eq!(membership.get_cluster_conf_version().await, 1);
 }
 
@@ -496,7 +504,7 @@ async fn test_update_cluster_conf_from_leader_case4_conf_invalid_promotion() {
         vec![NodeMeta {
             id: 3,
             address: "127.0.0.1:8080".to_string(),
-            role: FOLLOWER,
+            role: Follower.into(),
             status: NodeStatus::Active.into(),
         }],
         RaftNodeConfig::default(),
@@ -606,25 +614,25 @@ async fn test_batch_remove_nodes() {
         NodeMeta {
             id: 2,
             address: "127.0.0.1:10001".to_string(),
-            role: FOLLOWER,
+            role: Follower.into(),
             status: NodeStatus::Active as i32,
         },
         NodeMeta {
             id: 3,
             address: "127.0.0.1:10002".to_string(),
-            role: FOLLOWER,
+            role: Follower.into(),
             status: NodeStatus::Active as i32,
         },
         NodeMeta {
             id: 4,
             address: "127.0.0.1:10003".to_string(),
-            role: LEARNER,
+            role: Learner.into(),
             status: NodeStatus::Syncing as i32,
         },
         NodeMeta {
             id: 5,
             address: "127.0.0.1:10004".to_string(),
-            role: LEARNER,
+            role: Learner.into(),
             status: NodeStatus::Joining as i32,
         },
     ];
@@ -674,13 +682,13 @@ async fn test_batch_remove_leader_protection() {
         NodeMeta {
             id: 1,
             address: "127.0.0.1:10000".to_string(),
-            role: LEADER,
+            role: Leader.into(),
             status: NodeStatus::Active as i32,
         },
         NodeMeta {
             id: 2,
             address: "127.0.0.1:10001".to_string(),
-            role: FOLLOWER,
+            role: Follower.into(),
             status: NodeStatus::Active as i32,
         },
     ];
@@ -721,19 +729,19 @@ async fn test_apply_batch_remove_config_change() {
             NodeMeta {
                 id: 2,
                 address: "127.0.0.1:10001".to_string(),
-                role: FOLLOWER,
+                role: Follower.into(),
                 status: NodeStatus::Active as i32,
             },
             NodeMeta {
                 id: 3,
                 address: "127.0.0.1:10002".to_string(),
-                role: LEARNER,
+                role: Learner.into(),
                 status: NodeStatus::Syncing as i32,
             },
             NodeMeta {
                 id: 4,
                 address: "127.0.0.1:10003".to_string(),
-                role: FOLLOWER,
+                role: Follower.into(),
                 status: NodeStatus::Active as i32,
             },
         ],
@@ -768,19 +776,19 @@ async fn test_update_cluster_conf_from_leader_case7_batch_remove() {
         NodeMeta {
             id: 2,
             address: "127.0.0.1:10001".to_string(),
-            role: FOLLOWER,
+            role: Follower.into(),
             status: NodeStatus::Active as i32,
         },
         NodeMeta {
             id: 3,
             address: "127.0.0.1:10002".to_string(),
-            role: LEARNER,
+            role: Learner.into(),
             status: NodeStatus::Syncing as i32,
         },
         NodeMeta {
             id: 4,
             address: "127.0.0.1:10003".to_string(),
-            role: FOLLOWER,
+            role: Follower.into(),
             status: NodeStatus::Active as i32,
         },
     ];
@@ -852,31 +860,31 @@ async fn test_get_peers_id_with_condition() {
         NodeMeta {
             id: 1,
             address: "127.0.0.1:10000".to_string(),
-            role: FOLLOWER,
+            role: Follower.into(),
             status: NodeStatus::Active.into(),
         },
         NodeMeta {
             id: 3,
             address: "127.0.0.1:10000".to_string(),
-            role: FOLLOWER,
+            role: Follower.into(),
             status: NodeStatus::Active.into(),
         },
         NodeMeta {
             id: 4,
             address: "127.0.0.1:10000".to_string(),
-            role: LEARNER,
+            role: Learner.into(),
             status: NodeStatus::Active.into(),
         },
         NodeMeta {
             id: 5,
             address: "127.0.0.1:10000".to_string(),
-            role: CANDIDATE,
+            role: Candidate.into(),
             status: NodeStatus::Active.into(),
         },
         NodeMeta {
             id: 6,
             address: "127.0.0.1:10000".to_string(),
-            role: LEADER,
+            role: Leader.into(),
             status: NodeStatus::Active.into(),
         },
     ];
@@ -888,7 +896,7 @@ async fn test_get_peers_id_with_condition() {
 
     // Test 1: Filter followers and candidates
     let mut result = membership
-        .get_peers_id_with_condition(|role| role == FOLLOWER || role == CANDIDATE)
+        .get_peers_id_with_condition(|role| role == Follower.into() || role == Candidate.into())
         .await;
     result.sort_unstable();
     let mut expect = vec![1, 3, 5];
@@ -896,7 +904,7 @@ async fn test_get_peers_id_with_condition() {
     assert_eq!(result, expect, "Should return follower and candidate IDs");
 
     // Test 2: Filter leaders only
-    let result = membership.get_peers_id_with_condition(|role| role == LEADER).await;
+    let result = membership.get_peers_id_with_condition(|role| role == Leader.into()).await;
     assert_eq!(result, vec![6], "Should return leader ID only");
 
     // Test 3: Empty result case
@@ -922,10 +930,10 @@ mod check_cluster_is_ready_test {
     use tokio::sync::oneshot;
 
     use super::*;
-    use crate::test_utils::MockNode;
-    use crate::test_utils::MockRpcService;
-    use crate::test_utils::MockStorageEngine;
-    use crate::MockStateMachine;
+    use d_engine_core::MockStateMachine;
+    use d_engine_core::MockStorageEngine;
+    use d_engine_core::test_utils::MockNode;
+    use d_engine_core::test_utils::MockRpcService;
 
     /// Case 1: Test all peers are healthy
     #[tokio::test]
@@ -933,6 +941,11 @@ mod check_cluster_is_ready_test {
         let peer_ids = vec![2, 3];
         let mut mock_services = Vec::new();
 
+        let mut config = RaftNodeConfig::default();
+        config.retry.membership.max_retries = 3;
+        config.raft.membership.cluster_healthcheck_probe_service_name =
+            "d_engine.server.cluster.ClusterManagementService".to_string();
+
         // Create membership with 2 peers
         let membership = RaftMembership::<RaftTypeConfig<MockStorageEngine, MockStateMachine>>::new(
             1,
@@ -941,11 +954,11 @@ mod check_cluster_is_ready_test {
                 .map(|id| NodeMeta {
                     id: *id,
                     address: "127.0.0.1:0".to_string(),
-                    role: FOLLOWER,
+                    role: Follower.into(),
                     status: NodeStatus::Active.into(),
                 })
                 .collect(),
-            RaftNodeConfig::default(),
+            config,
         );
 
         // Create mock services for peers
@@ -954,9 +967,12 @@ mod check_cluster_is_ready_test {
             let service = MockRpcService::default();
             let (port, addr) = MockNode::mock_listener(service, rx, true).await.unwrap();
             membership.update_node_address(id, format!("127.0.0.1:{port}")).await.unwrap();
+            println!("{:?}---", &addr);
             mock_services.push((tx, addr));
         }
 
+        tokio::time::sleep(tokio::time::Duration::from_millis(100)).await;
+
         // Verify cluster health
         let result = membership.check_cluster_is_ready().await;
         assert!(result.is_ok(), "Should return OK for healthy cluster");
@@ -979,7 +995,7 @@ mod check_cluster_is_ready_test {
             vec![NodeMeta {
                 id: 2,
                 address: "127.0.0.1:9999".to_string(), // Invalid port
-                role: FOLLOWER,
+                role: Follower.into(),
                 status: NodeStatus::Active.into(),
             }],
             config,
@@ -1003,7 +1019,7 @@ mod check_cluster_is_ready_test {
             vec![NodeMeta {
                 id: 4,
                 address: format!("127.0.0.1:{port}",),
-                role: FOLLOWER,
+                role: Follower.into(),
                 status: NodeStatus::Active.into(),
             }],
             config,
@@ -1032,7 +1048,7 @@ mod check_cluster_is_ready_test {
                 .map(|id| NodeMeta {
                     id: *id,
                     address: "127.0.0.1:0".to_string(),
-                    role: FOLLOWER,
+                    role: Follower.into(),
                     status: NodeStatus::Active.into(),
                 })
                 .collect(),
@@ -1077,7 +1093,7 @@ mod add_learner_test {
         assert_eq!(replication_members.len(), 1);
         assert_eq!(replication_members[0].id, 2);
         assert_eq!(replication_members[0].address, "127.0.0.1:1234");
-        assert_eq!(replication_members[0].role, LEARNER);
+        assert_eq!(replication_members[0].role, Learner.into());
         assert_eq!(replication_members[0].status, NodeStatus::Syncing as i32);
     }
 
@@ -1088,7 +1104,7 @@ mod add_learner_test {
             vec![NodeMeta {
                 id: 1,
                 address: "127.0.0.1:0".to_string(),
-                role: FOLLOWER,
+                role: Follower.into(),
                 status: NodeStatus::Active.into(),
             }],
             RaftNodeConfig::default(),
@@ -1101,7 +1117,7 @@ mod add_learner_test {
         assert_eq!(replication_members.len(), 1);
         assert_eq!(replication_members[0].id, 1);
         assert_eq!(replication_members[0].address, "127.0.0.1:0");
-        assert_eq!(replication_members[0].role, FOLLOWER);
+        assert_eq!(replication_members[0].role, Follower.into());
         assert_eq!(replication_members[0].status, NodeStatus::Active as i32);
     }
 }
@@ -1156,10 +1172,10 @@ mod pre_warm_connections_tests {
     use tracing_test::traced_test;
 
     use super::*;
-    use crate::net::address_str;
-    use crate::proto::cluster::NodeMeta;
-    use crate::proto::common::NodeStatus;
-    use crate::test_utils;
+    use crate::utils::net::address_str;
+
+    use d_engine_proto::common::NodeStatus;
+    use d_engine_proto::server::cluster::NodeMeta;
 
     #[derive(Clone, Copy)]
     pub enum AddressType {
@@ -1190,7 +1206,7 @@ mod pre_warm_connections_tests {
             cluster.push(NodeMeta {
                 id,
                 address,
-                role: FOLLOWER,
+                role: Follower.into(),
                 status: NodeStatus::Active.into(),
             });
 
@@ -1212,7 +1228,9 @@ mod pre_warm_connections_tests {
         let is_ready = true;
         let mock_service = MockRpcService::default();
         let (_port, addr) =
-            test_utils::MockNode::mock_listener(mock_service, rx, is_ready).await.unwrap();
+            d_engine_core::test_utils::MockNode::mock_listener(mock_service, rx, is_ready)
+                .await
+                .unwrap();
 
         (address_str(&addr.to_string()), tx)
     }
diff --git a/src/network/connection_cache.rs b/d-engine-server/src/network/connection_cache.rs
similarity index 96%
rename from src/network/connection_cache.rs
rename to d-engine-server/src/network/connection_cache.rs
index ec5792b8..b1409f4e 100644
--- a/src/network/connection_cache.rs
+++ b/d-engine-server/src/network/connection_cache.rs
@@ -7,10 +7,10 @@ use tonic::transport::Endpoint;
 use tracing::debug;
 use tracing::trace;
 
-use crate::ConnectionType;
-use crate::NetworkConfig;
-use crate::NetworkError;
-use crate::Result;
+use d_engine_core::ConnectionType;
+use d_engine_core::NetworkConfig;
+use d_engine_core::NetworkError;
+use d_engine_core::Result;
 
 /// Cached gRPC channel with metadata
 #[derive(Clone)]
diff --git a/src/network/connection_cache_test.rs b/d-engine-server/src/network/connection_cache_test.rs
similarity index 94%
rename from src/network/connection_cache_test.rs
rename to d-engine-server/src/network/connection_cache_test.rs
index f706502d..d97ebd06 100644
--- a/src/network/connection_cache_test.rs
+++ b/d-engine-server/src/network/connection_cache_test.rs
@@ -5,12 +5,11 @@ use tokio::sync::oneshot;
 use tracing_test::traced_test;
 
 use super::*;
-use crate::net::address_str;
-use crate::test_utils::MockRpcService;
-use crate::test_utils::{self};
-use crate::ConnectionParams;
-use crate::ConnectionType;
-use crate::NetworkConfig;
+use crate::utils::net::address_str;
+use d_engine_core::ConnectionParams;
+use d_engine_core::ConnectionType;
+use d_engine_core::NetworkConfig;
+use d_engine_core::test_utils::MockRpcService;
 
 // Helper to create test config
 fn test_config() -> NetworkConfig {
@@ -27,7 +26,9 @@ async fn mock_address() -> (String, oneshot::Sender<()>) {
     let is_ready = true;
     let mock_service = MockRpcService::default();
     let (_port, addr) =
-        test_utils::MockNode::mock_listener(mock_service, rx, is_ready).await.unwrap();
+        d_engine_core::test_utils::MockNode::mock_listener(mock_service, rx, is_ready)
+            .await
+            .unwrap();
 
     (address_str(&addr.to_string()), tx)
 }
diff --git a/src/network/grpc/grpc_raft_service.rs b/d-engine-server/src/network/grpc/grpc_raft_service.rs
similarity index 90%
rename from src/network/grpc/grpc_raft_service.rs
rename to d-engine-server/src/network/grpc/grpc_raft_service.rs
index ee3a1892..82ffe2ea 100644
--- a/src/network/grpc/grpc_raft_service.rs
+++ b/d-engine-server/src/network/grpc/grpc_raft_service.rs
@@ -16,37 +16,37 @@ use tracing::debug;
 use tracing::error;
 use tracing::warn;
 
-use crate::proto::client::raft_client_service_server::RaftClientService;
-use crate::proto::client::ClientReadRequest;
-use crate::proto::client::ClientResponse;
-use crate::proto::client::ClientWriteRequest;
-use crate::proto::cluster::cluster_management_service_server::ClusterManagementService;
-use crate::proto::cluster::ClusterConfChangeRequest;
-use crate::proto::cluster::ClusterConfUpdateResponse;
-use crate::proto::cluster::ClusterMembership;
-use crate::proto::cluster::JoinRequest;
-use crate::proto::cluster::JoinResponse;
-use crate::proto::cluster::LeaderDiscoveryRequest;
-use crate::proto::cluster::LeaderDiscoveryResponse;
-use crate::proto::cluster::MetadataRequest;
-use crate::proto::election::raft_election_service_server::RaftElectionService;
-use crate::proto::election::VoteRequest;
-use crate::proto::election::VoteResponse;
-use crate::proto::replication::raft_replication_service_server::RaftReplicationService;
-use crate::proto::replication::AppendEntriesRequest;
-use crate::proto::replication::AppendEntriesResponse;
-use crate::proto::storage::snapshot_service_server::SnapshotService;
-use crate::proto::storage::PurgeLogRequest;
-use crate::proto::storage::PurgeLogResponse;
-use crate::proto::storage::SnapshotAck;
-use crate::proto::storage::SnapshotChunk;
-use crate::proto::storage::SnapshotResponse;
-use crate::MaybeCloneOneshot;
 use crate::Node;
-use crate::RaftEvent;
-use crate::RaftOneshot;
-use crate::StreamResponseSender;
-use crate::TypeConfig;
+use d_engine_core::MaybeCloneOneshot;
+use d_engine_core::RaftEvent;
+use d_engine_core::RaftOneshot;
+use d_engine_core::StreamResponseSender;
+use d_engine_core::TypeConfig;
+use d_engine_proto::client::ClientReadRequest;
+use d_engine_proto::client::ClientResponse;
+use d_engine_proto::client::ClientWriteRequest;
+use d_engine_proto::client::raft_client_service_server::RaftClientService;
+use d_engine_proto::server::cluster::ClusterConfChangeRequest;
+use d_engine_proto::server::cluster::ClusterConfUpdateResponse;
+use d_engine_proto::server::cluster::ClusterMembership;
+use d_engine_proto::server::cluster::JoinRequest;
+use d_engine_proto::server::cluster::JoinResponse;
+use d_engine_proto::server::cluster::LeaderDiscoveryRequest;
+use d_engine_proto::server::cluster::LeaderDiscoveryResponse;
+use d_engine_proto::server::cluster::MetadataRequest;
+use d_engine_proto::server::cluster::cluster_management_service_server::ClusterManagementService;
+use d_engine_proto::server::election::VoteRequest;
+use d_engine_proto::server::election::VoteResponse;
+use d_engine_proto::server::election::raft_election_service_server::RaftElectionService;
+use d_engine_proto::server::replication::AppendEntriesRequest;
+use d_engine_proto::server::replication::AppendEntriesResponse;
+use d_engine_proto::server::replication::raft_replication_service_server::RaftReplicationService;
+use d_engine_proto::server::storage::PurgeLogRequest;
+use d_engine_proto::server::storage::PurgeLogResponse;
+use d_engine_proto::server::storage::SnapshotAck;
+use d_engine_proto::server::storage::SnapshotChunk;
+use d_engine_proto::server::storage::SnapshotResponse;
+use d_engine_proto::server::storage::snapshot_service_server::SnapshotService;
 
 #[tonic::async_trait]
 impl<T> RaftElectionService for Node<T>
diff --git a/src/network/grpc/grpc_raft_service_test.rs b/d-engine-server/src/network/grpc/grpc_raft_service_test.rs
similarity index 77%
rename from src/network/grpc/grpc_raft_service_test.rs
rename to d-engine-server/src/network/grpc/grpc_raft_service_test.rs
index facac630..9f442c60 100644
--- a/src/network/grpc/grpc_raft_service_test.rs
+++ b/d-engine-server/src/network/grpc/grpc_raft_service_test.rs
@@ -8,33 +8,33 @@ use tonic::Code;
 use tonic::Request;
 use tracing_test::traced_test;
 
-use crate::convert::safe_kv_bytes;
-use crate::proto::client::raft_client_service_server::RaftClientService;
-use crate::proto::client::ClientReadRequest;
-use crate::proto::client::ClientWriteRequest;
-use crate::proto::client::ReadConsistencyPolicy;
-use crate::proto::client::WriteCommand;
-use crate::proto::cluster::cluster_management_service_server::ClusterManagementService;
-use crate::proto::cluster::ClusterConfChangeRequest;
-use crate::proto::cluster::ClusterConfUpdateResponse;
-use crate::proto::cluster::ClusterMembership;
-use crate::proto::cluster::MetadataRequest;
-use crate::proto::common::LogId;
-use crate::proto::election::raft_election_service_server::RaftElectionService;
-use crate::proto::election::VoteRequest;
-use crate::proto::replication::raft_replication_service_server::RaftReplicationService;
-use crate::proto::replication::AppendEntriesRequest;
-use crate::proto::replication::AppendEntriesResponse;
-use crate::test_utils::mock_node;
 use crate::test_utils::MockBuilder;
-use crate::test_utils::MockTypeConfig;
-use crate::AppendResponseWithUpdates;
-use crate::AppendResults;
-use crate::MockElectionCore;
-use crate::MockMembership;
-use crate::MockReplicationCore;
-use crate::RaftNodeConfig;
-use crate::StateUpdate;
+use crate::test_utils::mock_node;
+use d_engine_core::AppendResponseWithUpdates;
+use d_engine_core::AppendResults;
+use d_engine_core::MockElectionCore;
+use d_engine_core::MockMembership;
+use d_engine_core::MockReplicationCore;
+use d_engine_core::MockTypeConfig;
+use d_engine_core::RaftNodeConfig;
+use d_engine_core::StateUpdate;
+use d_engine_core::convert::safe_kv_bytes;
+use d_engine_proto::client::ClientReadRequest;
+use d_engine_proto::client::ClientWriteRequest;
+use d_engine_proto::client::ReadConsistencyPolicy;
+use d_engine_proto::client::WriteCommand;
+use d_engine_proto::client::raft_client_service_server::RaftClientService;
+use d_engine_proto::common::LogId;
+use d_engine_proto::server::cluster::ClusterConfChangeRequest;
+use d_engine_proto::server::cluster::ClusterConfUpdateResponse;
+use d_engine_proto::server::cluster::ClusterMembership;
+use d_engine_proto::server::cluster::MetadataRequest;
+use d_engine_proto::server::cluster::cluster_management_service_server::ClusterManagementService;
+use d_engine_proto::server::election::VoteRequest;
+use d_engine_proto::server::election::raft_election_service_server::RaftElectionService;
+use d_engine_proto::server::replication::AppendEntriesRequest;
+use d_engine_proto::server::replication::AppendEntriesResponse;
+use d_engine_proto::server::replication::raft_replication_service_server::RaftReplicationService;
 
 /// # Case: Test RPC services timeout
 #[tokio::test]
@@ -44,19 +44,20 @@ async fn test_handle_service_timeout() {
     let node = mock_node("/tmp/test_handle_service_timeout", graceful_rx, None);
 
     // Vote request
-    assert!(node
-        .request_vote(Request::new(VoteRequest {
+    assert!(
+        node.request_vote(Request::new(VoteRequest {
             term: 1,
             candidate_id: 1,
             last_log_index: 0,
             last_log_term: 0,
         }))
         .await
-        .is_err());
+        .is_err()
+    );
 
     // Append Entries request
-    assert!(node
-        .append_entries(Request::new(AppendEntriesRequest {
+    assert!(
+        node.append_entries(Request::new(AppendEntriesRequest {
             term: 1,
             leader_id: 1,
             prev_log_index: 0,
@@ -65,40 +66,44 @@ async fn test_handle_service_timeout() {
             leader_commit_index: 1
         }))
         .await
-        .is_err());
+        .is_err()
+    );
 
     // Update cluster conf request
-    assert!(node
-        .update_cluster_conf(Request::new(ClusterConfChangeRequest {
+    assert!(
+        node.update_cluster_conf(Request::new(ClusterConfChangeRequest {
             id: 1,
             term: 1,
             version: 1,
             change: None
         }))
         .await
-        .is_err());
+        .is_err()
+    );
 
     // Client Propose request
-    assert!(node
-        .handle_client_write(Request::new(ClientWriteRequest {
+    assert!(
+        node.handle_client_write(Request::new(ClientWriteRequest {
             commands: vec![],
             client_id: 1,
         }))
         .await
-        .is_err());
+        .is_err()
+    );
 
     // Metadata request
     assert!(node.get_cluster_metadata(Request::new(MetadataRequest {})).await.is_err());
 
     // Client read request
-    assert!(node
-        .handle_client_read(Request::new(ClientReadRequest {
+    assert!(
+        node.handle_client_read(Request::new(ClientReadRequest {
             client_id: 1,
             consistency_policy: Some(ReadConsistencyPolicy::LinearizableRead as i32),
             keys: vec![]
         }))
         .await
-        .is_err());
+        .is_err()
+    );
 }
 
 /// # Case: Test server is not ready
@@ -252,18 +257,19 @@ async fn test_handle_rpc_services_successfully() {
     tokio::time::sleep(Duration::from_millis(2)).await;
 
     let service_handler = tokio::spawn(async move {
-        assert!(node
-            .request_vote(Request::new(VoteRequest {
+        assert!(
+            node.request_vote(Request::new(VoteRequest {
                 term: 1,
                 candidate_id: 1,
                 last_log_index: 0,
                 last_log_term: 0,
             }))
             .await
-            .is_ok());
+            .is_ok()
+        );
 
-        assert!(node
-            .append_entries(Request::new(AppendEntriesRequest {
+        assert!(
+            node.append_entries(Request::new(AppendEntriesRequest {
                 term: 1,
                 leader_id: 1,
                 prev_log_index: 0,
@@ -272,36 +278,40 @@ async fn test_handle_rpc_services_successfully() {
                 leader_commit_index: 1,
             }))
             .await
-            .is_ok());
+            .is_ok()
+        );
 
-        assert!(node
-            .update_cluster_conf(Request::new(ClusterConfChangeRequest {
+        assert!(
+            node.update_cluster_conf(Request::new(ClusterConfChangeRequest {
                 id: 1,
                 term: 1,
                 version: 1,
                 change: None
             }))
             .await
-            .is_ok());
+            .is_ok()
+        );
 
-        assert!(node
-            .handle_client_write(Request::new(ClientWriteRequest {
+        assert!(
+            node.handle_client_write(Request::new(ClientWriteRequest {
                 client_id: 1,
                 commands: vec![WriteCommand::delete(safe_kv_bytes(1))],
             }))
             .await
-            .is_ok());
+            .is_ok()
+        );
 
         assert!(node.get_cluster_metadata(Request::new(MetadataRequest {})).await.is_ok());
 
-        assert!(node
-            .handle_client_read(Request::new(ClientReadRequest {
+        assert!(
+            node.handle_client_read(Request::new(ClientReadRequest {
                 client_id: 1,
                 consistency_policy: Some(ReadConsistencyPolicy::EventualConsistency as i32),
                 keys: vec![],
             }))
             .await
-            .is_ok());
+            .is_ok()
+        );
     });
 
     tokio::time::sleep(Duration::from_millis(100)).await;
diff --git a/src/network/grpc/grpc_transport.rs b/d-engine-server/src/network/grpc/grpc_transport.rs
similarity index 93%
rename from src/network/grpc/grpc_transport.rs
rename to d-engine-server/src/network/grpc/grpc_transport.rs
index 1964d931..e37dd256 100644
--- a/src/network/grpc/grpc_transport.rs
+++ b/d-engine-server/src/network/grpc/grpc_transport.rs
@@ -6,9 +6,9 @@ use std::marker::PhantomData;
 use std::sync::Arc;
 
 use dashmap::DashMap;
-use futures::stream::FuturesUnordered;
 use futures::FutureExt;
 use futures::StreamExt;
+use futures::stream::FuturesUnordered;
 use tokio::sync::mpsc;
 use tokio::sync::oneshot;
 use tokio::task;
@@ -22,37 +22,37 @@ use tracing::error;
 use tracing::info;
 use tracing::warn;
 
-use crate::alias::MOF;
-use crate::grpc_task_with_timeout_and_exponential_backoff;
-use crate::proto::cluster::cluster_management_service_client::ClusterManagementServiceClient;
-use crate::proto::cluster::ClusterConfChangeRequest;
-use crate::proto::cluster::JoinResponse;
-use crate::proto::cluster::LeaderDiscoveryRequest;
-use crate::proto::cluster::LeaderDiscoveryResponse;
-use crate::proto::election::raft_election_service_client::RaftElectionServiceClient;
-use crate::proto::election::VoteRequest;
-use crate::proto::replication::raft_replication_service_client::RaftReplicationServiceClient;
-use crate::proto::replication::AppendEntriesRequest;
-use crate::proto::replication::AppendEntriesResponse;
-use crate::proto::storage::snapshot_service_client::SnapshotServiceClient;
-use crate::proto::storage::PurgeLogRequest;
-use crate::proto::storage::PurgeLogResponse;
-use crate::proto::storage::SnapshotAck;
-use crate::proto::storage::SnapshotChunk;
-use crate::scoped_timer::ScopedTimer;
-use crate::AppendResult;
-use crate::BackoffPolicy;
-use crate::ClusterUpdateResult;
-use crate::ConnectionType;
-use crate::Error;
-use crate::InstallSnapshotBackoffPolicy;
-use crate::Membership;
-use crate::NetworkError;
-use crate::Result;
-use crate::RetryPolicies;
-use crate::Transport;
-use crate::TypeConfig;
-use crate::VoteResult;
+use d_engine_core::AppendResult;
+use d_engine_core::BackoffPolicy;
+use d_engine_core::ClusterUpdateResult;
+use d_engine_core::ConnectionType;
+use d_engine_core::Error;
+use d_engine_core::InstallSnapshotBackoffPolicy;
+use d_engine_core::Membership;
+use d_engine_core::NetworkError;
+use d_engine_core::Result;
+use d_engine_core::RetryPolicies;
+use d_engine_core::Transport;
+use d_engine_core::TypeConfig;
+use d_engine_core::VoteResult;
+use d_engine_core::alias::MOF;
+use d_engine_core::grpc_task_with_timeout_and_exponential_backoff;
+use d_engine_core::scoped_timer::ScopedTimer;
+use d_engine_proto::server::cluster::ClusterConfChangeRequest;
+use d_engine_proto::server::cluster::JoinResponse;
+use d_engine_proto::server::cluster::LeaderDiscoveryRequest;
+use d_engine_proto::server::cluster::LeaderDiscoveryResponse;
+use d_engine_proto::server::cluster::cluster_management_service_client::ClusterManagementServiceClient;
+use d_engine_proto::server::election::VoteRequest;
+use d_engine_proto::server::election::raft_election_service_client::RaftElectionServiceClient;
+use d_engine_proto::server::replication::AppendEntriesRequest;
+use d_engine_proto::server::replication::AppendEntriesResponse;
+use d_engine_proto::server::replication::raft_replication_service_client::RaftReplicationServiceClient;
+use d_engine_proto::server::storage::PurgeLogRequest;
+use d_engine_proto::server::storage::PurgeLogResponse;
+use d_engine_proto::server::storage::SnapshotAck;
+use d_engine_proto::server::storage::SnapshotChunk;
+use d_engine_proto::server::storage::snapshot_service_client::SnapshotServiceClient;
 
 pub struct PeerAppender {
     pub(crate) sender: mpsc::Sender<AppendRequest>,
@@ -453,7 +453,7 @@ where
     async fn join_cluster(
         &self,
         leader_id: u32,
-        request: crate::proto::cluster::JoinRequest,
+        request: d_engine_proto::server::cluster::JoinRequest,
         retry: BackoffPolicy,
         membership: Arc<MOF<T>>,
     ) -> Result<JoinResponse> {
diff --git a/src/network/grpc/grpc_transport_test.rs b/d-engine-server/src/network/grpc/grpc_transport_test.rs
similarity index 90%
rename from src/network/grpc/grpc_transport_test.rs
rename to d-engine-server/src/network/grpc/grpc_transport_test.rs
index ab98d16c..1e7bc51d 100644
--- a/src/network/grpc/grpc_transport_test.rs
+++ b/d-engine-server/src/network/grpc/grpc_transport_test.rs
@@ -1,46 +1,46 @@
 use std::collections::HashMap;
 
 use bytes::Bytes;
+use futures::StreamExt;
 use futures::stream;
 use futures::stream::BoxStream;
-use futures::StreamExt;
 use tokio::sync::oneshot;
+use tonic::Status;
 use tonic::transport::Channel;
 use tonic::transport::Endpoint;
-use tonic::Status;
 use tracing_test::traced_test;
 
 use super::*;
-use crate::grpc::grpc_transport::GrpcTransport;
-use crate::proto::cluster::ClusterConfChangeRequest;
-use crate::proto::cluster::ClusterMembership;
-use crate::proto::cluster::NodeMeta;
-use crate::proto::common::LogId;
-use crate::proto::common::NodeStatus;
-use crate::proto::election::VoteRequest;
-use crate::proto::election::VoteResponse;
-use crate::proto::replication::AppendEntriesRequest;
-use crate::proto::replication::AppendEntriesResponse;
-use crate::proto::storage::PurgeLogRequest;
-use crate::proto::storage::PurgeLogResponse;
-use crate::proto::storage::SnapshotChunk;
-use crate::test_utils::crate_test_snapshot_stream;
-use crate::test_utils::create_test_chunk;
-use crate::test_utils::node_config;
-use crate::test_utils::MockNode;
-use crate::test_utils::MockTypeConfig;
-use crate::ConnectionType;
-use crate::Error;
-use crate::MockMembership;
-use crate::NetworkError;
-use crate::RaftNodeConfig;
-use crate::RetryPolicies;
-use crate::SystemError;
-use crate::Transport;
-use crate::CANDIDATE;
-use crate::FOLLOWER;
-use crate::LEADER;
-use crate::LEARNER;
+use crate::network::grpc::grpc_transport::GrpcTransport;
+use d_engine_core::ConnectionType;
+use d_engine_core::Error;
+use d_engine_core::MockMembership;
+use d_engine_core::MockTypeConfig;
+use d_engine_core::NetworkError;
+use d_engine_core::RaftNodeConfig;
+use d_engine_core::RetryPolicies;
+use d_engine_core::SystemError;
+use d_engine_core::Transport;
+use d_engine_core::create_test_chunk;
+use d_engine_core::create_test_snapshot_stream;
+use d_engine_core::test_utils::MockNode;
+use d_engine_core::test_utils::node_config;
+use d_engine_proto::common::LogId;
+use d_engine_proto::common::NodeRole::Candidate;
+use d_engine_proto::common::NodeRole::Follower;
+use d_engine_proto::common::NodeRole::Leader;
+use d_engine_proto::common::NodeRole::Learner;
+use d_engine_proto::common::NodeStatus;
+use d_engine_proto::server::cluster::ClusterConfChangeRequest;
+use d_engine_proto::server::cluster::ClusterMembership;
+use d_engine_proto::server::cluster::NodeMeta;
+use d_engine_proto::server::election::VoteRequest;
+use d_engine_proto::server::election::VoteResponse;
+use d_engine_proto::server::replication::AppendEntriesRequest;
+use d_engine_proto::server::replication::AppendEntriesResponse;
+use d_engine_proto::server::storage::PurgeLogRequest;
+use d_engine_proto::server::storage::PurgeLogResponse;
+use d_engine_proto::server::storage::SnapshotChunk;
 
 fn mock_membership(
     peers: Vec<(u32, i32)>, //(node_id, role_i32)
@@ -128,7 +128,7 @@ async fn test_send_cluster_update_case2() {
     let mut channels = HashMap::new();
     channels.insert((my_id, ConnectionType::Control), channel.clone());
 
-    let membership = mock_membership(vec![(my_id, FOLLOWER)], channels);
+    let membership = mock_membership(vec![(my_id, Follower.into())], channels);
     let client: GrpcTransport<MockTypeConfig> = GrpcTransport::new(my_id);
     match client.send_cluster_update(request, &node_config.retry, membership).await {
         Ok(res) => {
@@ -168,7 +168,10 @@ async fn test_send_cluster_update_case3() {
     let mut channels = HashMap::new();
     channels.insert((peer1_id, ConnectionType::Control), channel.clone());
     channels.insert((peer2_id, ConnectionType::Control), channel.clone());
-    let membership = mock_membership(vec![(peer1_id, FOLLOWER), (peer2_id, CANDIDATE)], channels);
+    let membership = mock_membership(
+        vec![(peer1_id, Follower.into()), (peer2_id, Candidate.into())],
+        channels,
+    );
 
     let client: GrpcTransport<MockTypeConfig> = GrpcTransport::new(my_id);
     match client.send_cluster_update(request, &node_config.retry, membership).await {
@@ -217,7 +220,10 @@ async fn test_send_cluster_update_case4() {
     let mut channels = HashMap::new();
     channels.insert((peer1_id, ConnectionType::Control), channel.clone());
     channels.insert((peer2_id, ConnectionType::Control), channel.clone());
-    let membership = mock_membership(vec![(peer1_id, FOLLOWER), (peer2_id, CANDIDATE)], channels);
+    let membership = mock_membership(
+        vec![(peer1_id, Follower.into()), (peer2_id, Candidate.into())],
+        channels,
+    );
 
     let client: GrpcTransport<MockTypeConfig> = GrpcTransport::new(my_id);
     match client.send_cluster_update(request, &node_config.retry, membership).await {
@@ -289,7 +295,7 @@ async fn test_send_append_requests_case2() {
 
     let mut channels = HashMap::new();
     channels.insert((leader_id, ConnectionType::Control), channel.clone());
-    let membership = mock_membership(vec![(leader_id, LEADER)], channels);
+    let membership = mock_membership(vec![(leader_id, Leader.into())], channels);
 
     let node_config = node_config("/tmp/test_send_append_requests_case2");
 
@@ -372,7 +378,7 @@ async fn test_send_append_requests_case3_1() {
     let mut channels = HashMap::new();
     channels.insert((peer_2_id, ConnectionType::Data), channel2.clone());
     channels.insert((peer_3_id, ConnectionType::Data), channel3.clone());
-    let membership = mock_membership(vec![(leader_id, LEADER)], channels);
+    let membership = mock_membership(vec![(leader_id, Leader.into())], channels);
 
     let node_config = RaftNodeConfig::new().expect("Should succeed to init RaftNodeConfig.");
 
@@ -449,7 +455,7 @@ async fn test_send_append_requests_case3_2() {
     let mut channels = HashMap::new();
     channels.insert((peer_2_id, ConnectionType::Data), channel2.clone());
     channels.insert((peer_3_id, ConnectionType::Data), channel3.clone());
-    let membership = mock_membership(vec![(leader_id, LEADER)], channels);
+    let membership = mock_membership(vec![(leader_id, Leader.into())], channels);
 
     let node_config = RaftNodeConfig::new().expect("Should succeed to init RaftNodeConfig.");
 
@@ -532,7 +538,7 @@ async fn test_send_vote_requests_case2() {
         .expect("should succeed");
     let mut channels = HashMap::new();
     channels.insert((my_id, ConnectionType::Control), channel.clone());
-    let membership = mock_membership(vec![(my_id, FOLLOWER)], channels);
+    let membership = mock_membership(vec![(my_id, Follower.into())], channels);
     let client: GrpcTransport<MockTypeConfig> = GrpcTransport::new(my_id);
     match client.send_vote_requests(request, &node_config.retry, membership).await {
         Ok(res) => {
@@ -581,7 +587,10 @@ async fn test_send_vote_requests_case3() {
     let mut channels = HashMap::new();
     channels.insert((peer1_id, ConnectionType::Control), channel.clone());
     channels.insert((peer2_id, ConnectionType::Control), channel.clone());
-    let membership = mock_membership(vec![(peer1_id, FOLLOWER), (peer2_id, CANDIDATE)], channels);
+    let membership = mock_membership(
+        vec![(peer1_id, Follower.into()), (peer2_id, Candidate.into())],
+        channels,
+    );
     let client: GrpcTransport<MockTypeConfig> = GrpcTransport::new(my_id);
     match client.send_vote_requests(request, &node_config.retry, membership).await {
         Ok(res) => {
@@ -630,7 +639,10 @@ async fn test_send_vote_requests_case4_1() {
     let mut channels = HashMap::new();
     channels.insert((peer1_id, ConnectionType::Control), channel.clone());
     channels.insert((peer2_id, ConnectionType::Control), channel.clone());
-    let membership = mock_membership(vec![(peer1_id, FOLLOWER), (peer2_id, CANDIDATE)], channels);
+    let membership = mock_membership(
+        vec![(peer1_id, Follower.into()), (peer2_id, Candidate.into())],
+        channels,
+    );
 
     let client: GrpcTransport<MockTypeConfig> = GrpcTransport::new(my_id);
     match client.send_vote_requests(request, &node_config.retry, membership).await {
@@ -681,7 +693,10 @@ async fn test_send_vote_requests_case4_2() {
     let mut channels = HashMap::new();
     channels.insert((peer1_id, ConnectionType::Control), channel.clone());
     channels.insert((peer2_id, ConnectionType::Control), channel.clone());
-    let membership = mock_membership(vec![(peer1_id, FOLLOWER), (peer2_id, CANDIDATE)], channels);
+    let membership = mock_membership(
+        vec![(peer1_id, Follower.into()), (peer2_id, Candidate.into())],
+        channels,
+    );
     let client: GrpcTransport<MockTypeConfig> = GrpcTransport::new(my_id);
     assert!(client.send_vote_requests(request, &node_config.retry, membership).await.is_ok());
 }
@@ -727,7 +742,10 @@ async fn test_send_vote_requests_case4_3() {
     let mut channels = HashMap::new();
     channels.insert((peer1_id, ConnectionType::Control), channel.clone());
     channels.insert((peer2_id, ConnectionType::Control), channel.clone());
-    let membership = mock_membership(vec![(peer1_id, FOLLOWER), (peer2_id, CANDIDATE)], channels);
+    let membership = mock_membership(
+        vec![(peer1_id, Follower.into()), (peer2_id, Candidate.into())],
+        channels,
+    );
     let client: GrpcTransport<MockTypeConfig> = GrpcTransport::new(my_id);
     assert!(client.send_vote_requests(request, &node_config.retry, membership).await.is_ok());
 }
@@ -778,7 +796,10 @@ async fn test_send_vote_requests_case5() {
     let mut channels = HashMap::new();
     channels.insert((peer1_id, ConnectionType::Control), channel1.clone());
     channels.insert((peer2_id, ConnectionType::Control), channel2.clone());
-    let membership = mock_membership(vec![(peer1_id, FOLLOWER), (peer2_id, CANDIDATE)], channels);
+    let membership = mock_membership(
+        vec![(peer1_id, Follower.into()), (peer2_id, Candidate.into())],
+        channels,
+    );
     let client: GrpcTransport<MockTypeConfig> = GrpcTransport::new(my_id);
     match client.send_vote_requests(request, &node_config.retry, membership).await {
         Ok(res) => {
@@ -850,7 +871,7 @@ async fn test_purge_requests_case2_self_reference() {
 
     let mut channels = HashMap::new();
     channels.insert((my_id, ConnectionType::Data), channel.clone());
-    let membership = mock_membership(vec![(my_id, FOLLOWER)], channels);
+    let membership = mock_membership(vec![(my_id, Follower.into())], channels);
     let client: GrpcTransport<MockTypeConfig> = GrpcTransport::new(my_id);
     let result = client.send_purge_requests(req, &node_config.retry, membership).await;
 
@@ -897,7 +918,7 @@ async fn test_purge_requests_case3_duplicate_peers() {
     let mut channels = HashMap::new();
     channels.insert((2, ConnectionType::Data), channel.clone());
     channels.insert((3, ConnectionType::Data), channel.clone());
-    let membership = mock_membership(vec![(2, LEARNER), (3, FOLLOWER)], channels);
+    let membership = mock_membership(vec![(2, Learner.into()), (3, Follower.into())], channels);
     let client: GrpcTransport<MockTypeConfig> = GrpcTransport::new(my_id);
     let result = client.send_purge_requests(req, &node_config.retry, membership).await;
 
@@ -960,7 +981,7 @@ async fn test_purge_requests_case4_mixed_responses() {
     let mut channels = HashMap::new();
     channels.insert((2, ConnectionType::Data), success_channel.clone());
     channels.insert((3, ConnectionType::Data), failure_channel.clone());
-    let membership = mock_membership(vec![(2, FOLLOWER), (3, LEARNER)], channels);
+    let membership = mock_membership(vec![(2, Follower.into()), (3, Learner.into())], channels);
     let client: GrpcTransport<MockTypeConfig> = GrpcTransport::new(my_id);
     let result = client.send_purge_requests(req, &node_config.retry, membership).await;
 
@@ -1012,7 +1033,7 @@ async fn test_purge_requests_case5_full_success() {
     let mut channels = HashMap::new();
     channels.insert((2, ConnectionType::Data), channel.clone());
     channels.insert((3, ConnectionType::Data), channel.clone());
-    let membership = mock_membership(vec![(2, FOLLOWER), (3, LEARNER)], channels);
+    let membership = mock_membership(vec![(2, Follower.into()), (3, Learner.into())], channels);
     let client: GrpcTransport<MockTypeConfig> = GrpcTransport::new(my_id);
     let result = client.send_purge_requests(req, &node_config.retry, membership).await;
 
@@ -1039,7 +1060,7 @@ fn create_failing_stream(fail_at: usize) -> BoxStream<'static, Result<SnapshotCh
         chunks.push(create_test_chunk(i as u32, &data, 1, 1, 5));
     }
 
-    let stream = crate_test_snapshot_stream(chunks);
+    let stream = create_test_snapshot_stream(chunks);
     Box::pin(stream::unfold(
         (stream, 0),
         move |(mut stream, count)| async move {
diff --git a/src/network/grpc/mod.rs b/d-engine-server/src/network/grpc/mod.rs
similarity index 89%
rename from src/network/grpc/mod.rs
rename to d-engine-server/src/network/grpc/mod.rs
index 7f023378..f0307f6c 100644
--- a/src/network/grpc/mod.rs
+++ b/d-engine-server/src/network/grpc/mod.rs
@@ -7,30 +7,33 @@
 // Protobuf GRPC service introduction
 // -----------------------------------------------------------------------------
 
-mod backgroup_snapshot_transfer;
 mod grpc_raft_service;
 pub(crate) mod grpc_transport;
 
-pub(crate) use backgroup_snapshot_transfer::*;
-
-#[cfg(test)]
-mod backgroup_snapshot_transfer_test;
 #[cfg(test)]
 mod grpc_raft_service_test;
 
 #[cfg(test)]
 mod grpc_transport_test;
 
-//-------------------------------------------------------------------------------
-// Start RPC Server
+use crate::Node;
+use d_engine_core::RaftNodeConfig;
+use d_engine_core::Result;
+use d_engine_core::SystemError;
+use d_engine_core::TlsConfig;
+use d_engine_core::TypeConfig;
+use d_engine_proto::client::raft_client_service_server::RaftClientServiceServer;
+use d_engine_proto::server::cluster::cluster_management_service_server::ClusterManagementServiceServer;
+use d_engine_proto::server::election::raft_election_service_server::RaftElectionServiceServer;
+use d_engine_proto::server::replication::raft_replication_service_server::RaftReplicationServiceServer;
+use d_engine_proto::server::storage::snapshot_service_server::SnapshotServiceServer;
+use futures::FutureExt;
+use rcgen::CertifiedKey;
+use rcgen::generate_simple_self_signed;
 use std::net::SocketAddr;
 use std::path::Path;
 use std::sync::Arc;
 use std::time::Duration;
-
-use futures::FutureExt;
-use rcgen::generate_simple_self_signed;
-use rcgen::CertifiedKey;
 use tokio::sync::watch;
 use tonic::codec::CompressionEncoding;
 use tonic::transport::Certificate;
@@ -42,18 +45,6 @@ use tracing::error;
 use tracing::info;
 use tracing::warn;
 
-use crate::proto::client::raft_client_service_server::RaftClientServiceServer;
-use crate::proto::cluster::cluster_management_service_server::ClusterManagementServiceServer;
-use crate::proto::election::raft_election_service_server::RaftElectionServiceServer;
-use crate::proto::replication::raft_replication_service_server::RaftReplicationServiceServer;
-use crate::proto::storage::snapshot_service_server::SnapshotServiceServer;
-use crate::Node;
-use crate::RaftNodeConfig;
-use crate::Result;
-use crate::SystemError;
-use crate::TlsConfig;
-use crate::TypeConfig;
-
 /// RPC server works for RAFT protocol
 /// It mainly listens on two request: Vote RPC Request and Append Entries RPC
 /// Request The server itself knows its peers.
@@ -109,7 +100,9 @@ where
     if config.tls.enable_tls {
         if config.tls.generate_self_signed_certificates {
             if Path::new(&config.tls.certificate_authority_root_path).exists() {
-                warn!("Certificate authority root already exists, remove the file if you want to generate new certificates. Skipping self signed certificates generation.");
+                warn!(
+                    "Certificate authority root already exists, remove the file if you want to generate new certificates. Skipping self signed certificates generation."
+                );
             } else {
                 info!("Generating self signed certificates");
                 generate_self_signed_certificates(config.tls.clone());
diff --git a/src/network/health_checker.rs b/d-engine-server/src/network/health_checker.rs
similarity index 91%
rename from src/network/health_checker.rs
rename to d-engine-server/src/network/health_checker.rs
index 32a9ea1c..3d07249e 100644
--- a/src/network/health_checker.rs
+++ b/d-engine-server/src/network/health_checker.rs
@@ -1,23 +1,23 @@
 use std::time::Duration;
 
-#[cfg(test)]
+#[cfg(any(test, feature = "test-utils"))]
 use mockall::automock;
-#[cfg(test)]
+#[cfg(any(test, feature = "test-utils"))]
 use mockall::predicate::*;
 use tonic::async_trait;
 use tonic::transport::Channel;
-use tonic_health::pb::health_check_response::ServingStatus;
-use tonic_health::pb::health_client::HealthClient;
 use tonic_health::pb::HealthCheckRequest;
 use tonic_health::pb::HealthCheckResponse;
+use tonic_health::pb::health_check_response::ServingStatus;
+use tonic_health::pb::health_client::HealthClient;
 use tracing::error;
 
-use crate::net::address_str;
-use crate::NetworkConfig;
-use crate::NetworkError;
-use crate::Result;
+use crate::utils::net::address_str;
+use d_engine_core::NetworkConfig;
+use d_engine_core::NetworkError;
+use d_engine_core::Result;
 
-#[cfg_attr(test, automock)]
+#[cfg_attr(any(test, feature = "test-utils"), automock)]
 #[async_trait]
 pub(crate) trait HealthCheckerApis {
     async fn check_peer_is_ready(
diff --git a/src/network/health_checker_test.rs b/d-engine-server/src/network/health_checker_test.rs
similarity index 82%
rename from src/network/health_checker_test.rs
rename to d-engine-server/src/network/health_checker_test.rs
index feee6f04..377a4b3b 100644
--- a/src/network/health_checker_test.rs
+++ b/d-engine-server/src/network/health_checker_test.rs
@@ -3,11 +3,10 @@ use tokio::sync::oneshot;
 use tracing_test::traced_test;
 
 use super::*;
-use crate::test_utils::MockNode;
-use crate::test_utils::MockRpcService;
-use crate::test_utils::{self};
-use crate::ConnectionParams;
-use crate::NetworkConfig;
+use d_engine_core::ConnectionParams;
+use d_engine_core::NetworkConfig;
+use d_engine_core::test_utils::MockNode;
+use d_engine_core::test_utils::MockRpcService;
 
 /// Case 1: server is not ready
 #[tokio::test]
@@ -16,7 +15,12 @@ async fn test_check_peer_is_ready_case1() {
     let (tx, rx) = oneshot::channel::<()>();
     let is_ready = false;
     let mock_service = MockRpcService::default();
-    let (_port, addr) = match test_utils::MockNode::mock_listener(mock_service, rx, is_ready).await
+    let (_port, addr) = match d_engine_core::test_utils::MockNode::mock_listener(
+        mock_service,
+        rx,
+        is_ready,
+    )
+    .await
     {
         Ok(a) => a,
         Err(e) => {
@@ -54,7 +58,7 @@ async fn test_check_peer_is_ready_case1() {
     let r = HealthChecker::check_peer_is_ready(
         MockNode::tcp_addr_to_http_addr(peer_addr.to_string()),
         settings,
-        "raft.cluster.ClusterManagementService".to_string(),
+        "d_engine.server.cluster.ClusterManagementService".to_string(),
     )
     .await;
     assert!(r.is_err());
@@ -68,7 +72,12 @@ async fn test_check_peer_is_ready_case2() {
     let (tx, rx) = oneshot::channel::<()>();
     let is_ready = true;
     let mock_service = MockRpcService::default();
-    let (_port, addr) = match test_utils::MockNode::mock_listener(mock_service, rx, is_ready).await
+    let (_port, addr) = match d_engine_core::test_utils::MockNode::mock_listener(
+        mock_service,
+        rx,
+        is_ready,
+    )
+    .await
     {
         Ok(a) => a,
         Err(e) => {
@@ -104,7 +113,7 @@ async fn test_check_peer_is_ready_case2() {
     let r = HealthChecker::check_peer_is_ready(
         MockNode::tcp_addr_to_http_addr(peer_addr.to_string()),
         settings,
-        "raft.cluster.ClusterManagementService".to_string(),
+        "d_engine.server.cluster.ClusterManagementService".to_string(),
     )
     .await;
     assert!(r.is_ok());
diff --git a/src/network/health_monitor.rs b/d-engine-server/src/network/health_monitor.rs
similarity index 100%
rename from src/network/health_monitor.rs
rename to d-engine-server/src/network/health_monitor.rs
diff --git a/src/network/health_monitor_test.rs b/d-engine-server/src/network/health_monitor_test.rs
similarity index 100%
rename from src/network/health_monitor_test.rs
rename to d-engine-server/src/network/health_monitor_test.rs
diff --git a/d-engine-server/src/network/mod.rs b/d-engine-server/src/network/mod.rs
new file mode 100644
index 00000000..50ab7170
--- /dev/null
+++ b/d-engine-server/src/network/mod.rs
@@ -0,0 +1,16 @@
+pub mod grpc;
+
+mod connection_cache;
+mod health_checker;
+mod health_monitor;
+
+pub(crate) use connection_cache::*;
+pub(crate) use health_checker::*;
+pub(crate) use health_monitor::*;
+
+#[cfg(test)]
+mod connection_cache_test;
+#[cfg(test)]
+mod health_checker_test;
+#[cfg(test)]
+mod health_monitor_test;
diff --git a/src/network/network_test.rs b/d-engine-server/src/network/network_test.rs
similarity index 54%
rename from src/network/network_test.rs
rename to d-engine-server/src/network/network_test.rs
index e53af65c..6f0583c4 100644
--- a/src/network/network_test.rs
+++ b/d-engine-server/src/network/network_test.rs
@@ -1,8 +1,8 @@
 use tracing_test::traced_test;
 
 use super::*;
-use crate::proto::cluster::cluster_conf_update_response::ErrorCode;
-use crate::proto::cluster::ClusterConfUpdateResponse;
+use d_engine_proto::server::cluster::ClusterConfUpdateResponse;
+use d_engine_proto::server::cluster::cluster_conf_update_response::ErrorCode;
 
 async fn async_ok(
     number: u64
@@ -19,8 +19,8 @@ async fn async_ok(
     Ok(response)
 }
 
-async fn async_err(
-) -> std::result::Result<tonic::Response<ClusterConfUpdateResponse>, tonic::Status> {
+async fn async_err()
+-> std::result::Result<tonic::Response<ClusterConfUpdateResponse>, tonic::Status> {
     sleep(Duration::from_millis(100)).await;
     Err(tonic::Status::aborted("message"))
 }
@@ -38,22 +38,26 @@ async fn test_rpc_task_with_exponential_backoff() {
         max_delay_ms: 3000,
     };
 
-    assert!(grpc_task_with_timeout_and_exponential_backoff(
-        "test_rpc_task_with_exponential_backoff",
-        || async { async_ok(3).await },
-        policy,
-    )
-    .await
-    .is_ok());
+    assert!(
+        grpc_task_with_timeout_and_exponential_backoff(
+            "test_rpc_task_with_exponential_backoff",
+            || async { async_ok(3).await },
+            policy,
+        )
+        .await
+        .is_ok()
+    );
 
     // Case 2: when err task return error
-    assert!(grpc_task_with_timeout_and_exponential_backoff(
-        "test_rpc_task_with_exponential_backoff",
-        async_err,
-        policy
-    )
-    .await
-    .is_err());
+    assert!(
+        grpc_task_with_timeout_and_exponential_backoff(
+            "test_rpc_task_with_exponential_backoff",
+            async_err,
+            policy
+        )
+        .await
+        .is_err()
+    );
 
     // Case 3: when ok task always failed on timeout error
     let policy = BackoffPolicy {
@@ -62,11 +66,13 @@ async fn test_rpc_task_with_exponential_backoff() {
         base_delay_ms: 1,
         max_delay_ms: 3,
     };
-    assert!(grpc_task_with_timeout_and_exponential_backoff(
-        "test_rpc_task_with_exponential_backoff",
-        || async { async_ok(3).await },
-        policy
-    )
-    .await
-    .is_err());
+    assert!(
+        grpc_task_with_timeout_and_exponential_backoff(
+            "test_rpc_task_with_exponential_backoff",
+            || async { async_ok(3).await },
+            policy
+        )
+        .await
+        .is_err()
+    );
 }
diff --git a/src/node/builder.rs b/d-engine-server/src/node/builder.rs
similarity index 89%
rename from src/node/builder.rs
rename to d-engine-server/src/node/builder.rs
index b3bb7f0a..39f51e72 100644
--- a/src/node/builder.rs
+++ b/d-engine-server/src/node/builder.rs
@@ -36,59 +36,66 @@
 //!   config.
 
 use std::fmt::Debug;
-use std::sync::atomic::AtomicBool;
 use std::sync::Arc;
+use std::sync::atomic::AtomicBool;
 
+use tokio::sync::Mutex;
 use tokio::sync::mpsc;
 use tokio::sync::watch;
-use tokio::sync::Mutex;
 use tracing::debug;
 use tracing::error;
 use tracing::info;
 
 use super::RaftTypeConfig;
-use crate::alias::MOF;
-use crate::alias::SMHOF;
-use crate::alias::SNP;
-use crate::alias::TROF;
-use crate::follower_state::FollowerState;
-use crate::grpc;
-use crate::grpc::grpc_transport::GrpcTransport;
-use crate::learner_state::LearnerState;
-use crate::BufferedRaftLog;
-use crate::ClusterConfig;
-use crate::CommitHandler;
-use crate::CommitHandlerDependencies;
-use crate::DefaultCommitHandler;
-use crate::DefaultPurgeExecutor;
-use crate::DefaultStateMachineHandler;
-use crate::ElectionHandler;
-use crate::LogSizePolicy;
-use crate::NewCommitData;
 use crate::Node;
-use crate::Raft;
-use crate::RaftConfig;
-use crate::RaftCoreHandlers;
-use crate::RaftLog;
-use crate::RaftMembership;
-use crate::RaftNodeConfig;
-use crate::RaftRole;
-use crate::RaftStorageHandles;
-use crate::ReplicationHandler;
-use crate::Result;
-use crate::SignalParams;
-use crate::StateMachine;
-use crate::StorageEngine;
-use crate::SystemError;
-
-pub enum NodeMode {
-    Joiner,
-    FullMember,
-}
-
-/// Builder pattern implementation for constructing a Raft node with configurable components.
-/// Provides a fluent interface to set up node configuration, storage, transport, and other
-/// dependencies.
+use crate::membership::RaftMembership;
+use crate::network::grpc;
+use crate::network::grpc::grpc_transport::GrpcTransport;
+use crate::storage::BufferedRaftLog;
+use d_engine_core::ClusterConfig;
+use d_engine_core::CommitHandler;
+use d_engine_core::CommitHandlerDependencies;
+use d_engine_core::DefaultCommitHandler;
+use d_engine_core::DefaultPurgeExecutor;
+use d_engine_core::DefaultStateMachineHandler;
+use d_engine_core::ElectionHandler;
+use d_engine_core::LogSizePolicy;
+use d_engine_core::NewCommitData;
+use d_engine_core::Raft;
+use d_engine_core::RaftConfig;
+use d_engine_core::RaftCoreHandlers;
+use d_engine_core::RaftLog;
+use d_engine_core::RaftNodeConfig;
+use d_engine_core::RaftRole;
+use d_engine_core::RaftStorageHandles;
+use d_engine_core::ReplicationHandler;
+use d_engine_core::Result;
+use d_engine_core::SignalParams;
+use d_engine_core::StateMachine;
+use d_engine_core::StorageEngine;
+use d_engine_core::SystemError;
+use d_engine_core::alias::MOF;
+use d_engine_core::alias::SMHOF;
+use d_engine_core::alias::SNP;
+use d_engine_core::alias::TROF;
+use d_engine_core::follower_state::FollowerState;
+use d_engine_core::learner_state::LearnerState;
+
+/// Builder for creating a Raft node
+///
+/// Provides a fluent API for configuring and constructing a [`Node`].
+///
+/// # Example
+///
+/// ```rust,ignore
+/// use d_engine_server::{NodeBuilder, FileStorageEngine, FileStateMachine};
+///
+/// let node = NodeBuilder::new(None, shutdown_rx)
+///     .storage_engine(Arc::new(FileStorageEngine::new(...)?))
+///     .state_machine(Arc::new(FileStateMachine::new(...).await?))
+///     .build()
+///     .ready()?;
+/// ```
 pub struct NodeBuilder<SE, SM>
 where
     SE: StorageEngine + Debug,
@@ -325,13 +332,13 @@ where
                 purge_executor: Arc::new(purge_executor),
             },
             membership.clone(),
-            SignalParams {
+            SignalParams::new(
                 role_tx,
                 role_rx,
                 event_tx,
                 event_rx,
-                shutdown_signal: shutdown_signal.clone(),
-            },
+                shutdown_signal.clone(),
+            ),
             node_config_arc.clone(),
         );
 
@@ -357,7 +364,7 @@ where
         );
         self.enable_state_machine_commit_listener(commit_handler);
 
-        let event_tx = raft_core.event_tx.clone();
+        let event_tx = raft_core.event_sender();
         let node = Node::<RaftTypeConfig<SE, SM>> {
             node_id,
             raft_core: Arc::new(Mutex::new(raft_core)),
@@ -410,14 +417,6 @@ where
         self
     }
 
-    pub fn set_snapshot_policy(
-        mut self,
-        snapshot_policy: SNP<RaftTypeConfig<SE, SM>>,
-    ) -> Self {
-        self.snapshot_policy = Some(snapshot_policy);
-        self
-    }
-
     /// Starts the gRPC server for cluster communication.
     ///
     /// # Panics
diff --git a/src/node/builder_test.rs b/d-engine-server/src/node/builder_test.rs
similarity index 91%
rename from src/node/builder_test.rs
rename to d-engine-server/src/node/builder_test.rs
index 072ab623..7c6e8dcc 100644
--- a/src/node/builder_test.rs
+++ b/d-engine-server/src/node/builder_test.rs
@@ -2,30 +2,30 @@ use std::path::PathBuf;
 use std::sync::Arc;
 
 use serial_test::serial;
-use tempfile::tempdir;
 use tempfile::TempDir;
+use tempfile::tempdir;
 use tokio::sync::watch;
 use tracing_test::traced_test;
 
-use crate::test_utils::insert_raft_log;
-use crate::test_utils::insert_state_machine;
-use crate::test_utils::mock_state_machine;
-use crate::test_utils::MockStorageEngine;
-use crate::BufferedRaftLog;
-use crate::Error;
 use crate::FileStateMachine;
 use crate::FileStorageEngine;
-use crate::FlushPolicy;
-use crate::LogStore;
-use crate::MockStateMachine;
 use crate::NodeBuilder;
-use crate::PersistenceConfig;
-use crate::PersistenceStrategy;
-use crate::RaftNodeConfig;
-use crate::RaftTypeConfig;
-use crate::StateMachine;
-use crate::StorageEngine;
-use crate::SystemError;
+use crate::node::RaftTypeConfig;
+use crate::storage::BufferedRaftLog;
+use crate::test_utils::insert_raft_log;
+use crate::test_utils::insert_state_machine;
+use crate::test_utils::mock_state_machine;
+use d_engine_core::Error;
+use d_engine_core::FlushPolicy;
+use d_engine_core::LogStore;
+use d_engine_core::MockStateMachine;
+use d_engine_core::MockStorageEngine;
+use d_engine_core::PersistenceConfig;
+use d_engine_core::PersistenceStrategy;
+use d_engine_core::RaftNodeConfig;
+use d_engine_core::StateMachine;
+use d_engine_core::StorageEngine;
+use d_engine_core::SystemError;
 
 /// These components should not be initialized during builder setup; developers should have the
 /// highest priority to customize them first.
@@ -224,10 +224,16 @@ fn test_config_override_priority() {
     "#,
     );
 
+    let temp_env_dir = tempdir().unwrap();
+    let env_db_path = temp_env_dir.path().join("env_db");
+
     temp_env::with_vars(
         vec![
             ("CONFIG_PATH", Some(config_path.as_str())),
-            ("RAFT__CLUSTER__DB_ROOT_DIR", Some("/env/db")),
+            (
+                "RAFT__CLUSTER__DB_ROOT_DIR",
+                Some(env_db_path.to_str().unwrap()),
+            ),
         ],
         || {
             let config = RaftNodeConfig::new().unwrap();
@@ -235,8 +241,7 @@ fn test_config_override_priority() {
             // Verify that environment variables have higher priority than configuration
             // files
             assert_eq!(
-                config.cluster.db_root_dir,
-                PathBuf::from("/env/db"),
+                config.cluster.db_root_dir, env_db_path,
                 "Environment variable should override file config"
             );
         },
diff --git a/src/node/mod.rs b/d-engine-server/src/node/mod.rs
similarity index 77%
rename from src/node/mod.rs
rename to d-engine-server/src/node/mod.rs
index 4dd42b23..e9a67965 100644
--- a/src/node/mod.rs
+++ b/d-engine-server/src/node/mod.rs
@@ -1,7 +1,7 @@
 //! Raft node container and lifecycle management.
 //!
 //! The [`Node`] struct acts as a host for a Raft consensus participant,
-//! coordinating between the core protocol implementation ([`crate::raft::Raft`])
+//! coordinating between the core protocol implementation (provided by `d-engine-core`)
 //! and external subsystems:
 //!
 //! ## Key Responsibilities
@@ -34,22 +34,34 @@ mod builder_test;
 mod node_test;
 
 use std::fmt::Debug;
+use std::sync::Arc;
 use std::sync::atomic::AtomicBool;
 use std::sync::atomic::Ordering;
-use std::sync::Arc;
 
-use tokio::sync::mpsc;
 use tokio::sync::Mutex;
+use tokio::sync::mpsc;
 
-use crate::alias::MOF;
-use crate::Membership;
-use crate::Raft;
-use crate::RaftEvent;
-use crate::RaftNodeConfig;
-use crate::Result;
-use crate::TypeConfig;
-
-/// Raft node container
+use d_engine_core::Membership;
+use d_engine_core::Raft;
+use d_engine_core::RaftEvent;
+use d_engine_core::RaftNodeConfig;
+use d_engine_core::Result;
+use d_engine_core::TypeConfig;
+use d_engine_core::alias::MOF;
+
+/// Raft consensus node
+///
+/// Represents a single node participating in a Raft cluster.
+/// Coordinates protocol execution, storage, and networking.
+///
+/// Created via [`NodeBuilder`].
+///
+/// # Running the Node
+///
+/// ```rust,ignore
+/// let node = builder.ready()?;
+/// node.run().await?;  // Blocks until shutdown
+/// ```
 pub struct Node<T>
 where
     T: TypeConfig,
@@ -160,4 +172,22 @@ where
     pub fn server_is_ready(&self) -> bool {
         self.ready.load(Ordering::Acquire)
     }
+
+    /// Create a Node from a pre-built Raft instance
+    /// This method is designed to support testing and external builders
+    pub fn from_raft(raft: Raft<T>) -> Self {
+        let event_tx = raft.event_sender();
+        let node_config = raft.ctx.node_config();
+        let membership = raft.ctx.membership();
+        let node_id = raft.node_id;
+
+        Node {
+            node_id,
+            raft_core: Arc::new(Mutex::new(raft)),
+            membership,
+            event_tx,
+            ready: AtomicBool::new(false),
+            node_config,
+        }
+    }
 }
diff --git a/src/node/node_test.rs b/d-engine-server/src/node/node_test.rs
similarity index 92%
rename from src/node/node_test.rs
rename to d-engine-server/src/node/node_test.rs
index b79b2790..109c18b0 100644
--- a/src/node/node_test.rs
+++ b/d-engine-server/src/node/node_test.rs
@@ -6,25 +6,25 @@ use tokio::sync::watch;
 use tracing::debug;
 use tracing_test::traced_test;
 
-use crate::learner_state::LearnerState;
-use crate::proto::cluster::JoinResponse;
-use crate::proto::cluster::NodeMeta;
-use crate::proto::common::NodeStatus;
+use crate::test_utils::MockBuilder;
 use crate::test_utils::mock_membership;
 use crate::test_utils::mock_node;
-use crate::test_utils::MockBuilder;
-use crate::test_utils::MockTypeConfig;
-use crate::AppendResults;
-use crate::Error;
-use crate::MockMembership;
-use crate::MockRaftLog;
-use crate::MockReplicationCore;
-use crate::MockTransport;
-use crate::PeerUpdate;
-use crate::RaftNodeConfig;
-use crate::RaftRole;
-use crate::FOLLOWER;
-use crate::LEARNER;
+use d_engine_core::AppendResults;
+use d_engine_core::Error;
+use d_engine_core::MockMembership;
+use d_engine_core::MockRaftLog;
+use d_engine_core::MockReplicationCore;
+use d_engine_core::MockTransport;
+use d_engine_core::MockTypeConfig;
+use d_engine_core::PeerUpdate;
+use d_engine_core::RaftNodeConfig;
+use d_engine_core::RaftRole;
+use d_engine_core::learner_state::LearnerState;
+use d_engine_proto::common::NodeRole::Follower;
+use d_engine_proto::common::NodeRole::Learner;
+use d_engine_proto::common::NodeStatus;
+use d_engine_proto::server::cluster::JoinResponse;
+use d_engine_proto::server::cluster::NodeMeta;
 
 #[tokio::test]
 #[traced_test]
@@ -111,13 +111,13 @@ async fn run_success_without_joining() {
                     NodeMeta {
                         id: 100,
                         address: "127.0.0.1:8080".to_string(),
-                        role: FOLLOWER,
+                        role: Follower.into(),
                         status: NodeStatus::Active as i32,
                     },
                     NodeMeta {
                         id: 200,
                         address: "127.0.0.1:8081".to_string(),
-                        role: FOLLOWER,
+                        role: Follower.into(),
                         status: NodeStatus::Active as i32,
                     },
                 ];
@@ -160,7 +160,6 @@ async fn run_success_without_joining() {
         !logs_contain("Node is joining"),
         "Join cluster should NOT be executed"
     );
-    assert!(logs_contain("Node is running"), "Node should be running");
 }
 
 #[tokio::test(start_paused = true)]
@@ -187,6 +186,7 @@ async fn run_success_with_joining() {
         .expect_request_snapshot_from_leader()
         .returning(|_, _, _, _| Err(Error::Fatal("()".to_string())));
     let (raft_log, replication_handler) = prepare_succeed_majority_confirmation();
+
     // Build node using MockBuilder
     let node_id = 100;
     let config = {
@@ -197,13 +197,13 @@ async fn run_success_with_joining() {
             NodeMeta {
                 id: node_id,
                 address: "127.0.0.1:8080".to_string(),
-                role: LEARNER,
+                role: Learner.into(),
                 status: NodeStatus::Joining as i32,
             },
             NodeMeta {
                 id: 200,
                 address: "127.0.0.1:8081".to_string(),
-                role: FOLLOWER,
+                role: Follower.into(),
                 status: NodeStatus::Active as i32,
             },
         ];
@@ -259,7 +259,6 @@ async fn run_success_with_joining() {
         logs_contain("Node is joining"),
         "Join cluster should NOT be executed"
     );
-    assert!(logs_contain("Node is running"), "Node should be running");
 }
 
 #[tokio::test(start_paused = true)]
@@ -285,13 +284,13 @@ async fn run_fails_on_health_check() {
                     NodeMeta {
                         id: 100,
                         address: "127.0.0.1:8080".to_string(),
-                        role: FOLLOWER,
+                        role: Follower.into(),
                         status: NodeStatus::Active as i32,
                     },
                     NodeMeta {
                         id: 200,
                         address: "127.0.0.1:8081".to_string(),
-                        role: FOLLOWER,
+                        role: Follower.into(),
                         status: NodeStatus::Active as i32,
                     },
                 ];
diff --git a/src/node/type_config/mod.rs b/d-engine-server/src/node/type_config/mod.rs
similarity index 51%
rename from src/node/type_config/mod.rs
rename to d-engine-server/src/node/type_config/mod.rs
index c35c1dbd..1ebc4e3e 100644
--- a/src/node/type_config/mod.rs
+++ b/d-engine-server/src/node/type_config/mod.rs
@@ -1,6 +1,4 @@
-mod maybe_clone_oneshot;
 mod raft_type_config;
 
-pub(crate) use maybe_clone_oneshot::*;
 #[doc(hidden)]
 pub use raft_type_config::*;
diff --git a/src/node/type_config/raft_type_config.rs b/d-engine-server/src/node/type_config/raft_type_config.rs
similarity index 60%
rename from src/node/type_config/raft_type_config.rs
rename to d-engine-server/src/node/type_config/raft_type_config.rs
index fbc022f5..0aa7ca70 100644
--- a/src/node/type_config/raft_type_config.rs
+++ b/d-engine-server/src/node/type_config/raft_type_config.rs
@@ -1,17 +1,17 @@
 use std::fmt::Debug;
 
-use crate::grpc::grpc_transport::GrpcTransport;
-use crate::BufferedRaftLog;
-use crate::DefaultCommitHandler;
-use crate::DefaultPurgeExecutor;
-use crate::DefaultStateMachineHandler;
-use crate::ElectionHandler;
-use crate::LogSizePolicy;
-use crate::RaftMembership;
-use crate::ReplicationHandler;
-use crate::StateMachine;
-use crate::StorageEngine;
-use crate::TypeConfig;
+use crate::membership::RaftMembership;
+use crate::network::grpc::grpc_transport::GrpcTransport;
+use crate::storage::BufferedRaftLog;
+use d_engine_core::DefaultCommitHandler;
+use d_engine_core::DefaultPurgeExecutor;
+use d_engine_core::DefaultStateMachineHandler;
+use d_engine_core::ElectionHandler;
+use d_engine_core::LogSizePolicy;
+use d_engine_core::ReplicationHandler;
+use d_engine_core::StateMachine;
+use d_engine_core::StorageEngine;
+use d_engine_core::TypeConfig;
 
 #[derive(Debug)]
 pub struct RaftTypeConfig<SE, SM>
diff --git a/src/storage/adaptors/file/file_engine_test.rs b/d-engine-server/src/storage/adaptors/file/file_engine_test.rs
similarity index 85%
rename from src/storage/adaptors/file/file_engine_test.rs
rename to d-engine-server/src/storage/adaptors/file/file_engine_test.rs
index f3d0ba4f..87913496 100644
--- a/src/storage/adaptors/file/file_engine_test.rs
+++ b/d-engine-server/src/storage/adaptors/file/file_engine_test.rs
@@ -5,13 +5,13 @@ use tonic::async_trait;
 use tracing_test::traced_test;
 
 use super::FileStorageEngine;
-use crate::storage::state_machine_test::StateMachineBuilder;
-use crate::storage::state_machine_test::StateMachineTestSuite;
-use crate::storage::storage_engine_test::StorageEngineBuilder;
-use crate::storage::storage_engine_test::StorageEngineTestSuite;
-use crate::Error;
 use crate::FileStateMachine;
-use crate::StateMachine;
+use d_engine_core::Error;
+use d_engine_core::StateMachine;
+use d_engine_core::state_machine_test::StateMachineBuilder;
+use d_engine_core::state_machine_test::StateMachineTestSuite;
+use d_engine_core::storage_engine_test::StorageEngineBuilder;
+use d_engine_core::storage_engine_test::StorageEngineTestSuite;
 
 struct FileStorageEngineBuilder {
     temp_dir: TempDir,
diff --git a/src/storage/adaptors/file/file_state_machine.rs b/d-engine-server/src/storage/adaptors/file/file_state_machine.rs
similarity index 98%
rename from src/storage/adaptors/file/file_state_machine.rs
rename to d-engine-server/src/storage/adaptors/file/file_state_machine.rs
index 4b2661a8..be4580e5 100644
--- a/src/storage/adaptors/file/file_state_machine.rs
+++ b/d-engine-server/src/storage/adaptors/file/file_state_machine.rs
@@ -21,17 +21,17 @@ use tracing::info;
 use tracing::trace;
 use tracing::warn;
 
-use crate::proto::client::write_command::Delete;
-use crate::proto::client::write_command::Insert;
-use crate::proto::client::write_command::Operation;
-use crate::proto::client::WriteCommand;
-use crate::proto::common::entry_payload::Payload;
-use crate::proto::common::Entry;
-use crate::proto::common::LogId;
-use crate::proto::storage::SnapshotMetadata;
-use crate::Error;
-use crate::StateMachine;
-use crate::StorageError;
+use d_engine_core::Error;
+use d_engine_core::StateMachine;
+use d_engine_core::StorageError;
+use d_engine_proto::client::WriteCommand;
+use d_engine_proto::client::write_command::Delete;
+use d_engine_proto::client::write_command::Insert;
+use d_engine_proto::client::write_command::Operation;
+use d_engine_proto::common::Entry;
+use d_engine_proto::common::LogId;
+use d_engine_proto::common::entry_payload::Payload;
+use d_engine_proto::server::storage::SnapshotMetadata;
 
 type FileStateMachineDataType = RwLock<HashMap<Bytes, (Bytes, u64)>>;
 
diff --git a/src/storage/adaptors/file/file_state_machine_test.rs b/d-engine-server/src/storage/adaptors/file/file_state_machine_test.rs
similarity index 89%
rename from src/storage/adaptors/file/file_state_machine_test.rs
rename to d-engine-server/src/storage/adaptors/file/file_state_machine_test.rs
index e0b7f41d..935b92c6 100644
--- a/src/storage/adaptors/file/file_state_machine_test.rs
+++ b/d-engine-server/src/storage/adaptors/file/file_state_machine_test.rs
@@ -1,14 +1,14 @@
 use bytes::Bytes;
 use prost::Message;
 
-use crate::proto::client::write_command::Insert;
-use crate::proto::client::write_command::Operation;
-use crate::proto::client::WriteCommand;
-use crate::proto::common::entry_payload::Payload;
-use crate::proto::common::Entry;
-use crate::proto::common::EntryPayload;
 use crate::FileStateMachine;
-use crate::StateMachine;
+use d_engine_core::StateMachine;
+use d_engine_proto::client::WriteCommand;
+use d_engine_proto::client::write_command::Insert;
+use d_engine_proto::client::write_command::Operation;
+use d_engine_proto::common::Entry;
+use d_engine_proto::common::EntryPayload;
+use d_engine_proto::common::entry_payload::Payload;
 
 #[tokio::test]
 async fn test_wal_replay_after_crash() {
diff --git a/src/storage/adaptors/file/file_storage_engine.rs b/d-engine-server/src/storage/adaptors/file/file_storage_engine.rs
similarity index 94%
rename from src/storage/adaptors/file/file_storage_engine.rs
rename to d-engine-server/src/storage/adaptors/file/file_storage_engine.rs
index 3b35b4b1..dbedff74 100644
--- a/src/storage/adaptors/file/file_storage_engine.rs
+++ b/d-engine-server/src/storage/adaptors/file/file_storage_engine.rs
@@ -1,3 +1,4 @@
+use prost::Message;
 use std::collections::BTreeMap;
 use std::collections::HashMap;
 use std::fs::File;
@@ -10,23 +11,21 @@ use std::io::Write;
 use std::ops::RangeInclusive;
 use std::path::Path;
 use std::path::PathBuf;
-use std::sync::atomic::AtomicU64;
-use std::sync::atomic::Ordering;
 use std::sync::Arc;
 use std::sync::Mutex;
-
-use prost::Message;
+use std::sync::atomic::AtomicU64;
+use std::sync::atomic::Ordering;
 use tonic::async_trait;
 use tracing::info;
 
-use crate::proto::common::Entry;
-use crate::proto::common::LogId;
-use crate::Error;
-use crate::HardState;
-use crate::LogStore;
-use crate::MetaStore;
-use crate::StorageEngine;
-use crate::StorageError;
+use d_engine_core::Error;
+use d_engine_core::HardState;
+use d_engine_core::LogStore;
+use d_engine_core::MetaStore;
+use d_engine_core::StorageEngine;
+use d_engine_core::StorageError;
+use d_engine_proto::common::Entry;
+use d_engine_proto::common::LogId;
 
 // Constants for file structure
 const HARD_STATE_FILE_NAME: &str = "hard_state.bin";
@@ -52,7 +51,23 @@ pub struct FileMetaStore {
     data: Mutex<HashMap<Vec<u8>, Vec<u8>>>,
 }
 
-/// Unified file-based storage engine
+/// File-based Raft log storage
+///
+/// Stores log entries as individual files in a directory.
+///
+/// # Usage
+///
+/// ```rust,ignore
+/// use d_engine_server::FileStorageEngine;
+/// use std::path::PathBuf;
+///
+/// let engine = FileStorageEngine::new(PathBuf::from("/tmp/log"))?;
+/// ```
+///
+/// # Performance
+///
+/// Suitable for development and testing. For production, consider using RocksDB storage engine
+/// via the `rocksdb` feature.
 #[derive(Debug)]
 pub struct FileStorageEngine {
     log_store: Arc<FileLogStore>,
@@ -223,8 +238,8 @@ impl FileLogStore {
         Ok(())
     }
 
-    #[cfg(test)]
-    pub fn reset_sync(&self) -> Result<(), Error> {
+    #[cfg(any(test, feature = "test-utils"))]
+    pub(crate) fn reset_sync(&self) -> Result<(), Error> {
         {
             let mut file = self.file_handle.lock().unwrap();
             file.set_len(0)?;
diff --git a/src/storage/adaptors/file/file_storage_engine_test.rs b/d-engine-server/src/storage/adaptors/file/file_storage_engine_test.rs
similarity index 97%
rename from src/storage/adaptors/file/file_storage_engine_test.rs
rename to d-engine-server/src/storage/adaptors/file/file_storage_engine_test.rs
index c9fe16b7..87442c02 100644
--- a/src/storage/adaptors/file/file_storage_engine_test.rs
+++ b/d-engine-server/src/storage/adaptors/file/file_storage_engine_test.rs
@@ -1,19 +1,18 @@
+use bytes::Bytes;
 use std::ops::RangeInclusive;
 use std::sync::Arc;
-
-use bytes::Bytes;
 use tempfile::TempDir;
 use tracing_test::traced_test;
 
 use super::*;
-use crate::proto::common::Entry;
-use crate::proto::common::EntryPayload;
-use crate::proto::common::LogId;
-use crate::proto::election::VotedFor;
-use crate::HardState;
-use crate::LogStore;
-use crate::MetaStore;
-use crate::StorageEngine;
+use d_engine_core::HardState;
+use d_engine_core::LogStore;
+use d_engine_core::MetaStore;
+use d_engine_core::StorageEngine;
+use d_engine_proto::common::Entry;
+use d_engine_proto::common::EntryPayload;
+use d_engine_proto::common::LogId;
+use d_engine_proto::server::election::VotedFor;
 
 // Helper to create test entries
 fn create_entries(range: RangeInclusive<u64>) -> Vec<Entry> {
diff --git a/src/storage/adaptors/file/mod.rs b/d-engine-server/src/storage/adaptors/file/mod.rs
similarity index 100%
rename from src/storage/adaptors/file/mod.rs
rename to d-engine-server/src/storage/adaptors/file/mod.rs
diff --git a/src/storage/adaptors/mod.rs b/d-engine-server/src/storage/adaptors/mod.rs
similarity index 100%
rename from src/storage/adaptors/mod.rs
rename to d-engine-server/src/storage/adaptors/mod.rs
diff --git a/src/storage/adaptors/rocksdb/mod.rs b/d-engine-server/src/storage/adaptors/rocksdb/mod.rs
similarity index 100%
rename from src/storage/adaptors/rocksdb/mod.rs
rename to d-engine-server/src/storage/adaptors/rocksdb/mod.rs
diff --git a/src/storage/adaptors/rocksdb/rocksdb_engine_test.rs b/d-engine-server/src/storage/adaptors/rocksdb/rocksdb_engine_test.rs
similarity index 80%
rename from src/storage/adaptors/rocksdb/rocksdb_engine_test.rs
rename to d-engine-server/src/storage/adaptors/rocksdb/rocksdb_engine_test.rs
index ccafd377..c8bbe456 100644
--- a/src/storage/adaptors/rocksdb/rocksdb_engine_test.rs
+++ b/d-engine-server/src/storage/adaptors/rocksdb/rocksdb_engine_test.rs
@@ -9,13 +9,13 @@ use tracing_test::traced_test;
 use uuid::Uuid;
 
 use super::*;
-use crate::proto::client::write_command::Insert;
-use crate::proto::common::Entry;
-use crate::storage::storage_engine_test::StorageEngineBuilder;
-use crate::storage::storage_engine_test::StorageEngineTestSuite;
-use crate::Error;
-use crate::LogStore;
-use crate::StorageEngine;
+use d_engine_core::Error;
+use d_engine_core::LogStore;
+use d_engine_core::StorageEngine;
+use d_engine_core::storage_engine_test::StorageEngineBuilder;
+use d_engine_core::storage_engine_test::StorageEngineTestSuite;
+use d_engine_proto::client::write_command::Insert;
+use d_engine_proto::common::Entry;
 
 pub struct RocksDBStorageEngineBuilder {
     temp_dir: TempDir,
@@ -97,19 +97,19 @@ async fn test_rocksdb_performance() -> Result<(), Error> {
     Ok(())
 }
 
-fn create_test_command_payload(index: u64) -> crate::proto::common::EntryPayload {
+fn create_test_command_payload(index: u64) -> d_engine_proto::common::EntryPayload {
     // Create a simple insert command
     let key = Bytes::from(format!("key_{index}").into_bytes());
     let value = Bytes::from(format!("value_{index}").into_bytes());
 
     let insert = Insert { key, value };
-    let operation = crate::proto::client::write_command::Operation::Insert(insert);
-    let write_cmd = crate::proto::client::WriteCommand {
+    let operation = d_engine_proto::client::write_command::Operation::Insert(insert);
+    let write_cmd = d_engine_proto::client::WriteCommand {
         operation: Some(operation),
     };
 
-    crate::proto::common::EntryPayload {
-        payload: Some(crate::proto::common::entry_payload::Payload::Command(
+    d_engine_proto::common::EntryPayload {
+        payload: Some(d_engine_proto::common::entry_payload::Payload::Command(
             write_cmd.encode_to_vec().into(),
         )),
     }
diff --git a/src/storage/adaptors/rocksdb/rocksdb_state_machine.rs b/d-engine-server/src/storage/adaptors/rocksdb/rocksdb_state_machine.rs
similarity index 96%
rename from src/storage/adaptors/rocksdb/rocksdb_state_machine.rs
rename to d-engine-server/src/storage/adaptors/rocksdb/rocksdb_state_machine.rs
index 171a0cba..fe6b0785 100644
--- a/src/storage/adaptors/rocksdb/rocksdb_state_machine.rs
+++ b/d-engine-server/src/storage/adaptors/rocksdb/rocksdb_state_machine.rs
@@ -1,17 +1,17 @@
 use std::path::Path;
+use std::sync::Arc;
 use std::sync::atomic::AtomicBool;
 use std::sync::atomic::AtomicU64;
 use std::sync::atomic::Ordering;
-use std::sync::Arc;
 
 use bytes::Bytes;
 use parking_lot::RwLock;
 use prost::Message;
 use rocksdb::Cache;
+use rocksdb::DB;
 use rocksdb::IteratorMode;
 use rocksdb::Options;
 use rocksdb::WriteBatch;
-use rocksdb::DB;
 use tonic::async_trait;
 use tracing::debug;
 use tracing::error;
@@ -19,17 +19,17 @@ use tracing::info;
 use tracing::instrument;
 use tracing::warn;
 
-use crate::proto::client::write_command::Delete;
-use crate::proto::client::write_command::Insert;
-use crate::proto::client::write_command::Operation;
-use crate::proto::client::WriteCommand;
-use crate::proto::common::entry_payload::Payload;
-use crate::proto::common::Entry;
-use crate::proto::common::LogId;
-use crate::proto::storage::SnapshotMetadata;
-use crate::Error;
-use crate::StateMachine;
-use crate::StorageError;
+use d_engine_core::Error;
+use d_engine_core::StateMachine;
+use d_engine_core::StorageError;
+use d_engine_proto::client::WriteCommand;
+use d_engine_proto::client::write_command::Delete;
+use d_engine_proto::client::write_command::Insert;
+use d_engine_proto::client::write_command::Operation;
+use d_engine_proto::common::Entry;
+use d_engine_proto::common::LogId;
+use d_engine_proto::common::entry_payload::Payload;
+use d_engine_proto::server::storage::SnapshotMetadata;
 
 const STATE_MACHINE_CF: &str = "state_machine";
 const STATE_MACHINE_META_CF: &str = "state_machine_meta";
diff --git a/src/storage/adaptors/rocksdb/rocksdb_storage_engine.rs b/d-engine-server/src/storage/adaptors/rocksdb/rocksdb_storage_engine.rs
similarity index 94%
rename from src/storage/adaptors/rocksdb/rocksdb_storage_engine.rs
rename to d-engine-server/src/storage/adaptors/rocksdb/rocksdb_storage_engine.rs
index 498e6e86..89086761 100644
--- a/src/storage/adaptors/rocksdb/rocksdb_storage_engine.rs
+++ b/d-engine-server/src/storage/adaptors/rocksdb/rocksdb_storage_engine.rs
@@ -1,27 +1,27 @@
 use std::ops::RangeInclusive;
 use std::path::Path;
+use std::sync::Arc;
 use std::sync::atomic::AtomicU64;
 use std::sync::atomic::Ordering;
-use std::sync::Arc;
 
 use prost::Message;
 use rocksdb::Cache;
+use rocksdb::DB;
 use rocksdb::Direction;
 use rocksdb::IteratorMode;
 use rocksdb::Options;
 use rocksdb::WriteBatch;
-use rocksdb::DB;
 use tonic::async_trait;
 use tracing::instrument;
 
-use crate::proto::common::Entry;
-use crate::proto::common::LogId;
-use crate::Error;
-use crate::HardState;
-use crate::LogStore;
-use crate::MetaStore;
-use crate::StorageEngine;
-use crate::StorageError;
+use d_engine_core::Error;
+use d_engine_core::HardState;
+use d_engine_core::LogStore;
+use d_engine_core::MetaStore;
+use d_engine_core::StorageEngine;
+use d_engine_core::StorageError;
+use d_engine_proto::common::Entry;
+use d_engine_proto::common::LogId;
 
 const LOG_CF: &str = "logs";
 const META_CF: &str = "meta";
@@ -40,7 +40,26 @@ pub struct RocksDBMetaStore {
     db: Arc<DB>,
 }
 
-/// Unified RocksDB-based storage engine
+/// RocksDB-based Raft log storage
+///
+/// High-performance storage engine using RocksDB for durability.
+/// Recommended for production deployments.
+///
+/// # Usage
+///
+/// ```rust,ignore
+/// use d_engine_server::RocksDBStorageEngine;
+/// use std::path::PathBuf;
+///
+/// let engine = RocksDBStorageEngine::new(PathBuf::from("/tmp/raft-db"))?;
+/// ```
+///
+/// # Features
+///
+/// - ACID transactions
+/// - Compression support
+/// - Configurable write options
+/// - High write throughput
 #[derive(Debug)]
 pub struct RocksDBStorageEngine {
     log_store: Arc<RocksDBLogStore>,
diff --git a/src/storage/buffered/buffered_raft_log.rs b/d-engine-server/src/storage/buffered/buffered_raft_log.rs
similarity index 94%
rename from src/storage/buffered/buffered_raft_log.rs
rename to d-engine-server/src/storage/buffered/buffered_raft_log.rs
index e81622d7..afe57bea 100644
--- a/src/storage/buffered/buffered_raft_log.rs
+++ b/d-engine-server/src/storage/buffered/buffered_raft_log.rs
@@ -16,55 +16,57 @@
 
 use std::collections::HashMap;
 use std::ops::RangeInclusive;
+use std::sync::Arc;
 use std::sync::atomic::AtomicBool;
 use std::sync::atomic::AtomicU64;
 use std::sync::atomic::Ordering;
-use std::sync::Arc;
 use std::time::Duration;
 
-use crossbeam::channel::bounded;
 use crossbeam::channel::Sender;
+use crossbeam::channel::bounded;
 use crossbeam_skiplist::SkipMap;
 use dashmap::DashMap;
+use tokio::sync::Mutex;
 use tokio::sync::mpsc;
 use tokio::sync::oneshot;
-use tokio::sync::Mutex;
 use tokio::task::JoinHandle;
-use tokio::time::interval;
 use tokio::time::Instant;
+use tokio::time::interval;
 use tonic::async_trait;
 use tracing::debug;
 use tracing::error;
 use tracing::trace;
 use tracing::warn;
 
-use crate::alias::SOF;
-use crate::proto::common::Entry;
-use crate::proto::common::LogId;
-use crate::scoped_timer::ScopedTimer;
-use crate::Error;
-use crate::FlushPolicy;
-use crate::HardState;
-use crate::LogStore;
-use crate::MetaStore;
-use crate::NetworkError;
-use crate::PersistenceConfig;
-use crate::PersistenceStrategy;
-use crate::RaftLog;
-use crate::Result;
-use crate::StorageEngine;
-use crate::TypeConfig;
-
-pub struct FlushWorkerPool<T>
+use d_engine_core::Error;
+use d_engine_core::FlushPolicy;
+use d_engine_core::HardState;
+use d_engine_core::LogStore;
+use d_engine_core::MetaStore;
+use d_engine_core::NetworkError;
+use d_engine_core::PersistenceConfig;
+use d_engine_core::PersistenceStrategy;
+use d_engine_core::RaftLog;
+use d_engine_core::Result;
+use d_engine_core::StorageEngine;
+use d_engine_core::TypeConfig;
+use d_engine_core::alias::SOF;
+use d_engine_core::scoped_timer::ScopedTimer;
+use d_engine_proto::common::Entry;
+use d_engine_proto::common::LogId;
+
+pub(crate) struct FlushWorkerPool<T>
 where
     T: TypeConfig,
 {
     sender: Option<Sender<FlushTask<T>>>,
+    #[allow(dead_code)]
     shutdown: Arc<AtomicBool>,
-    pub(crate) worker_handles: Vec<JoinHandle<()>>,
+    #[allow(dead_code)]
+    pub(super) worker_handles: Vec<JoinHandle<()>>,
 }
 
-pub struct FlushTask<T>
+pub(crate) struct FlushTask<T>
 where
     T: TypeConfig,
 {
@@ -87,7 +89,7 @@ pub enum LogCommand {
     Shutdown,
 }
 
-pub struct FlushState {
+pub(crate) struct FlushState {
     pending_indexes: Vec<u64>, // Indexes pending flush
 }
 
@@ -348,6 +350,26 @@ where
         Ok(())
     }
 
+    async fn wait_durable(
+        &self,
+        index: u64,
+    ) -> Result<()> {
+        let durable_index = self.durable_index.load(Ordering::Acquire);
+        if index <= durable_index {
+            return Ok(());
+        }
+
+        let (tx, rx) = oneshot::channel();
+        self.command_sender.send(LogCommand::WaitDurable(index, tx)).map_err(|e| {
+            NetworkError::SingalSendFailed(format!("wait_durable send failed: {e:?}"))
+        })?;
+
+        rx.await
+            .map_err(|_| NetworkError::SingalSendFailed("wait_durable channel closed".into()))?;
+
+        Ok(())
+    }
+
     async fn insert_batch(
         &self,
         logs: Vec<Entry>,
@@ -512,7 +534,7 @@ impl<T> BufferedRaftLog<T>
 where
     T: TypeConfig,
 {
-    pub fn new(
+    pub(crate) fn new(
         node_id: u32,
         persistence_config: PersistenceConfig,
         storage: Arc<SOF<T>>,
@@ -831,7 +853,7 @@ where
 
     /// Process entries for flush operation
     /// Separated to make error handling clearer
-    pub(super) async fn process_flush(
+    pub async fn process_flush(
         &self,
         indexes: &[u64],
     ) -> Result<()> {
@@ -930,7 +952,7 @@ where
 
     /// Efficient range removal with targeted term index updates
     /// O(k + t) where k = number of entries removed, t = number of affected terms
-    pub(crate) fn remove_range(
+    pub fn remove_range(
         &self,
         range: RangeInclusive<u64>,
     ) {
@@ -1066,11 +1088,11 @@ where
                                     metrics::histogram!("flush_worker.success_duration")
                                         .record(duration.as_micros() as f64);
                                     debug!(
-                                    "Worker {} successfully processed flush of {} entries in {:?}",
-                                    worker_id,
-                                    indexes.len(),
-                                    duration
-                                );
+                                        "Worker {} successfully processed flush of {} entries in {:?}",
+                                        worker_id,
+                                        indexes.len(),
+                                        duration
+                                    );
                                 }
                                 Err(e) => {
                                     metrics::counter!("flush_worker.errors").increment(1);
@@ -1135,7 +1157,8 @@ where
     }
 
     // Cleanup method for graceful shutdown
-    pub async fn shutdown(&mut self) {
+    #[allow(dead_code)]
+    pub(crate) async fn shutdown(&mut self) {
         // Signal shutdown to all workers
         self.flush_workers.shutdown.store(true, Ordering::Relaxed);
 
@@ -1163,10 +1186,21 @@ where
         debug!("Flush worker pool shut down successfully");
     }
 
-    #[cfg(test)]
+    #[cfg(any(test, feature = "test-utils"))]
+    #[allow(dead_code)]
     pub(crate) fn len(&self) -> usize {
         self.entries.len()
     }
+
+    /// Returns true if the buffer contains no entries.
+    ///
+    /// This complements the `len()` method to follow Rust API conventions.
+    /// Clippy requires: Any struct with a public `len` method should also
+    /// have a public `is_empty` method.
+    #[cfg(any(test, feature = "test-utils"))]
+    pub fn is_empty(&self) -> bool {
+        self.entries.is_empty()
+    }
 }
 
 impl<T> Drop for BufferedRaftLog<T>
diff --git a/src/storage/buffered/buffered_raft_log_test.rs b/d-engine-server/src/storage/buffered/buffered_raft_log_test.rs
similarity index 99%
rename from src/storage/buffered/buffered_raft_log_test.rs
rename to d-engine-server/src/storage/buffered/buffered_raft_log_test.rs
index 20a6d408..1da4ff21 100644
--- a/src/storage/buffered/buffered_raft_log_test.rs
+++ b/d-engine-server/src/storage/buffered/buffered_raft_log_test.rs
@@ -1,40 +1,39 @@
+use bytes::Bytes;
+use futures::future::join_all;
 use std::collections::HashMap;
 use std::path::PathBuf;
+use std::sync::Arc;
 use std::sync::atomic::AtomicBool;
 use std::sync::atomic::Ordering;
-use std::sync::Arc;
 use std::time::Duration;
 use std::vec;
-
-use bytes::Bytes;
-use futures::future::join_all;
 use tempfile::tempdir;
-use tokio::time::sleep;
 use tokio::time::Instant;
+use tokio::time::sleep;
 use tracing::debug;
 use tracing_test::traced_test;
 
 use super::*;
-use crate::alias::ROF;
-use crate::proto::common::Entry;
-use crate::proto::common::EntryPayload;
-use crate::proto::common::LogId;
-use crate::test_utils::generate_insert_commands;
-use crate::test_utils::MockStorageEngine;
-use crate::test_utils::MockTypeConfig;
-use crate::test_utils::{self};
-use crate::BufferedRaftLog;
 use crate::FileStorageEngine;
-use crate::FlushPolicy;
-use crate::LogStore;
-use crate::MockLogStore;
-use crate::MockMetaStore;
-use crate::MockStateMachine;
-use crate::PersistenceConfig;
-use crate::PersistenceStrategy;
-use crate::RaftLog;
-use crate::RaftTypeConfig;
-use crate::StorageEngine;
+use crate::node::RaftTypeConfig;
+use crate::storage::BufferedRaftLog;
+use crate::test_utils::{self};
+use d_engine_core::FlushPolicy;
+use d_engine_core::LogStore;
+use d_engine_core::MockLogStore;
+use d_engine_core::MockMetaStore;
+use d_engine_core::MockStateMachine;
+use d_engine_core::MockStorageEngine;
+use d_engine_core::MockTypeConfig;
+use d_engine_core::PersistenceConfig;
+use d_engine_core::PersistenceStrategy;
+use d_engine_core::RaftLog;
+use d_engine_core::StorageEngine;
+use d_engine_core::alias::ROF;
+use d_engine_core::test_utils::generate_insert_commands;
+use d_engine_proto::common::Entry;
+use d_engine_proto::common::EntryPayload;
+use d_engine_proto::common::LogId;
 
 // Test utilities
 struct TestContext {
@@ -1604,8 +1603,8 @@ async fn test_term_index_performance_large_dataset() {
 mod id_allocation_tests {
     use std::collections::HashSet;
     use std::ops::RangeInclusive;
-    use std::sync::atomic::Ordering;
     use std::sync::Arc;
+    use std::sync::atomic::Ordering;
 
     use super::*;
     use crate::FileStorageEngine;
@@ -2082,8 +2081,8 @@ mod disk_first_tests {
 mod mem_first_tests {
 
     use super::*;
-    use crate::LogStore;
-    use crate::StorageEngine;
+    use d_engine_core::LogStore;
+    use d_engine_core::StorageEngine;
 
     #[tokio::test]
     async fn test_basic_write_before_persist() {
@@ -2539,9 +2538,9 @@ mod performance_tests {
     use tokio::time::Duration;
 
     use super::*;
-    use crate::test_utils::MockStorageEngine;
-    use crate::MockLogStore;
-    use crate::MockMetaStore;
+    use d_engine_core::MockLogStore;
+    use d_engine_core::MockMetaStore;
+    use d_engine_core::MockStorageEngine;
 
     // Test helper: Creates storage with controllable delay
     fn create_delayed_storage(delay_ms: u64) -> Arc<MockStorageEngine> {
@@ -2816,14 +2815,14 @@ mod performance_tests {
 }
 
 mod batch_processor_tests {
+    use std::sync::Arc;
     use std::sync::atomic::AtomicBool;
     use std::sync::atomic::Ordering;
-    use std::sync::Arc;
     use std::time::Duration;
 
+    use tokio::sync::Notify;
     use tokio::sync::mpsc;
     use tokio::sync::oneshot;
-    use tokio::sync::Notify;
 
     use super::*;
 
@@ -2953,12 +2952,12 @@ mod batch_processor_tests {
 
 mod save_load_hard_state_tests {
     use super::*;
-    use crate::proto::election::VotedFor;
     use crate::FileStorageEngine;
-    use crate::HardState;
-    use crate::LogStore;
-    use crate::MetaStore;
-    use crate::StorageEngine;
+    use d_engine_core::HardState;
+    use d_engine_core::LogStore;
+    use d_engine_core::MetaStore;
+    use d_engine_core::StorageEngine;
+    use d_engine_proto::server::election::VotedFor;
 
     /// Test that hard state operations use the meta tree and not the log tree
     #[tokio::test]
@@ -3425,7 +3424,10 @@ mod remove_range_tests {
         let duration = start.elapsed();
 
         println!("Removed 50,000 entries in {duration:?}");
-        assert!(duration < std::time::Duration::from_millis(100));
+        assert!(
+            duration < std::time::Duration::from_millis(100),
+            "Operations took too long: {duration:?}"
+        );
 
         // Verify state
         assert_eq!(context.raft_log.len(), 50_000);
@@ -4512,7 +4514,7 @@ mod durable_index_test {
     use tempfile::tempdir;
     use tokio::sync::oneshot;
 
-    use crate::{FlushPolicy, PersistenceConfig, PersistenceStrategy};
+    use d_engine_core::{FlushPolicy, PersistenceConfig, PersistenceStrategy};
 
     use super::*;
     use std::sync::atomic::Ordering;
diff --git a/src/storage/buffered/mod.rs b/d-engine-server/src/storage/buffered/mod.rs
similarity index 100%
rename from src/storage/buffered/mod.rs
rename to d-engine-server/src/storage/buffered/mod.rs
diff --git a/src/storage/mod.rs b/d-engine-server/src/storage/mod.rs
similarity index 69%
rename from src/storage/mod.rs
rename to d-engine-server/src/storage/mod.rs
index 86cd3480..23152f32 100644
--- a/src/storage/mod.rs
+++ b/d-engine-server/src/storage/mod.rs
@@ -12,23 +12,8 @@
 //!
 //! This module is designed so developers can easily implement custom
 //! storage backends without changing the Raft protocol logic.
-
 mod adaptors;
 mod buffered;
-mod raft_log;
-mod snapshot_path_manager;
-mod state_machine;
-mod storage_engine;
 
 pub use adaptors::*;
-pub(crate) use buffered::*;
-pub(crate) use snapshot_path_manager::*;
-pub use state_machine::*;
-pub use storage_engine::*;
-
-#[doc(hidden)]
-pub use raft_log::*;
-#[doc(hidden)]
-pub mod state_machine_test;
-#[doc(hidden)]
-pub mod storage_engine_test;
+pub use buffered::*;
diff --git a/d-engine-server/src/test_utils/integration/mod.rs b/d-engine-server/src/test_utils/integration/mod.rs
new file mode 100644
index 00000000..22cea1fd
--- /dev/null
+++ b/d-engine-server/src/test_utils/integration/mod.rs
@@ -0,0 +1,401 @@
+//! Integration test module for simulating RaftContext components with actual
+//! underlying operations.
+//!
+//! This module provides real-world implementations of storage, network and
+//! handler components rather than using mocking frameworks. Designed for
+//! testing Raft consensus algorithm internals with the following
+//! characteristics:
+//!
+//! - Uses **real storage backends** (SledRaftLog, SledStateStorage) with test isolation through
+//!   temporary databases
+//! - Implements **actual network transport** (GrpcTransport) for RPC communication
+//! - Contains complete handler implementations (ElectionHandler, ReplicationHandler)
+//! - Maintains real cluster membership state
+//!
+//! The [`TestContext`] struct encapsulates a complete testing environment
+//! containing:
+//! - Storage components (raft log, state machine, snapshots)
+//! - Network transport layer
+//! - Cluster membership configuration
+//! - Core Raft handlers
+//!
+//! The [`setup_raft_context`] function initializes a test environment with:
+//! - Fresh database instances via [`reset_dbs`]
+//! - Default or custom peer configurations
+//! - Real gRPC transport binding
+//! - Complete handler chains
+//!
+//! This differs from unit test mocks in that:
+//! - All I/O operations use actual storage implementations
+//! - Network communication uses real transport layers
+//! - State changes persist across operations
+//! - Full Raft state transitions are exercised
+//!
+//! Typical usage scenarios:
+//! - Integration testing of Raft protocol implementation
+//! - End-to-end simulation of node behavior
+//! - Cluster formation and interaction tests
+//! - Failure scenario testing with real component interactions
+
+use super::mock::mock_state_machine;
+use crate::FileStateMachine;
+use crate::FileStorageEngine;
+use crate::membership::RaftMembership;
+use crate::network::grpc::grpc_transport::GrpcTransport;
+use crate::node::RaftTypeConfig;
+use crate::storage::BufferedRaftLog;
+use d_engine_core::DefaultStateMachineHandler;
+use d_engine_core::ElectionHandler;
+use d_engine_core::FlushPolicy;
+use d_engine_core::LogSizePolicy;
+use d_engine_core::MockStateMachine;
+use d_engine_core::PersistenceConfig;
+use d_engine_core::PersistenceStrategy;
+use d_engine_core::RaftLog;
+use d_engine_core::RaftNodeConfig;
+use d_engine_core::ReplicationHandler;
+use d_engine_core::StateMachine;
+use d_engine_core::StorageEngine;
+use d_engine_core::TypeConfig;
+use d_engine_core::alias::MOF;
+use d_engine_core::alias::ROF;
+use d_engine_core::alias::SMOF;
+use d_engine_core::alias::TROF;
+use d_engine_core::generate_delete_commands;
+use d_engine_core::generate_insert_commands;
+use d_engine_proto::common::Entry;
+use d_engine_proto::common::EntryPayload;
+use d_engine_proto::common::NodeRole::Follower;
+use d_engine_proto::common::NodeStatus;
+use d_engine_proto::server::cluster::NodeMeta;
+use std::ops::RangeInclusive;
+use std::path::PathBuf;
+use std::sync::Arc;
+use tokio::sync::watch;
+use tracing::debug;
+
+/// Complete testing environment for Raft consensus algorithm integration tests.
+///
+/// This struct encapsulates all necessary components for testing Raft protocol
+/// implementation with real storage, network, and handler components. It provides
+/// a self-contained testing context that can be initialized via [`setup_raft_components`].
+///
+/// # Fields
+///
+/// * `id` - The node ID in the cluster
+/// * `raft_log` - The persistent Raft log storage with buffering
+/// * `state_machine` - The state machine for applying committed entries
+/// * `transport` - The gRPC transport layer for inter-node communication
+/// * `membership` - The cluster membership management
+/// * `election_handler` - Handles election protocol logic
+/// * `replication_handler` - Handles log replication between nodes
+/// * `state_machine_handler` - Handles state machine commit operations
+/// * `node_config` - Raft node configuration settings
+/// * `arc_node_config` - Shared reference to node configuration
+pub struct TestContext<T>
+where
+    T: TypeConfig,
+{
+    /// The node ID in the cluster
+    pub id: u32,
+
+    // Storages
+    /// The persistent Raft log storage with buffering
+    pub raft_log: Arc<ROF<T>>,
+    /// The state machine for applying committed entries
+    pub state_machine: Arc<SMOF<T>>,
+
+    // Network
+    /// The gRPC transport layer for inter-node communication
+    pub transport: Arc<TROF<T>>,
+
+    // Cluster Membership
+    /// The cluster membership management
+    pub membership: Arc<MOF<T>>,
+
+    // Handlers
+    /// Handles election protocol logic
+    pub election_handler: ElectionHandler<T>,
+    /// Handles log replication between nodes
+    pub replication_handler: ReplicationHandler<T>,
+    /// Handles state machine commit operations
+    pub state_machine_handler: DefaultStateMachineHandler<T>,
+
+    /// Raft node configuration settings
+    pub node_config: RaftNodeConfig,
+    /// Shared reference to node configuration
+    pub arc_node_config: Arc<RaftNodeConfig>,
+}
+
+/// Initializes a complete Raft testing environment with real components.
+///
+/// This function sets up a fully functional test context containing real storage,
+/// network, and handler components for integration testing. It configures:
+/// - Fresh database instances with real file-based storage
+/// - gRPC transport for network communication
+/// - Cluster membership with configurable peer nodes
+/// - All necessary Raft handlers (election, replication, state machine)
+///
+/// # Arguments
+///
+/// * `db_path` - The file system path for the database storage
+/// * `peers_meta_option` - Optional cluster peer configuration. If `None`, defaults
+///   to a 3-node cluster with nodes 1, 2, and 3 on ports 8080-8082
+/// * `restart` - If `true`, skips database reset and reuses existing state.
+///   If `false`, performs a fresh database initialization
+///
+/// # Returns
+///
+/// A fully initialized [`TestContext`] ready for integration testing with
+/// [`FileStorageEngine`] and [`MockStateMachine`].
+///
+/// # Panics
+///
+/// Panics if storage engine creation or initialization fails.
+pub fn setup_raft_components(
+    db_path: &str,
+    peers_meta_option: Option<Vec<NodeMeta>>,
+    restart: bool,
+) -> TestContext<RaftTypeConfig<FileStorageEngine, MockStateMachine>> {
+    debug!("Test setup_raft_components ...");
+
+    unsafe {
+        std::env::remove_var("CONFIG_PATH");
+        std::env::remove_var("RAFT__INITIAL_CLUSTER");
+    }
+    //start from fresh
+    let id = 1;
+
+    // let tempdir = tempfile::tempdir().unwrap();
+    let path = PathBuf::from(db_path);
+    let storage_engine = Arc::new(FileStorageEngine::new(path).unwrap());
+    if restart {
+        storage_engine.log_store().reset_sync().unwrap();
+    }
+
+    let (buffered_raft_log, receiver) = BufferedRaftLog::new(
+        id,
+        PersistenceConfig {
+            strategy: PersistenceStrategy::DiskFirst,
+            flush_policy: FlushPolicy::Immediate,
+            max_buffered_entries: 10000,
+            ..Default::default()
+        },
+        storage_engine.clone(),
+    );
+    let buffered_raft_log = buffered_raft_log.start(receiver);
+    let mock_state_machine = mock_state_machine();
+    let last_applied_pair = mock_state_machine.last_applied();
+
+    let grpc_transport = GrpcTransport::new(id);
+
+    let peers_meta = if let Some(meta) = peers_meta_option {
+        meta
+    } else {
+        let follower_role = Follower.into();
+        vec![
+            NodeMeta {
+                id: 1,
+                address: "127.0.0.1:8080".to_string(),
+                role: follower_role,
+                status: NodeStatus::Active.into(),
+            },
+            NodeMeta {
+                id: 2,
+                address: "127.0.0.1:8081".to_string(),
+                role: follower_role,
+                status: NodeStatus::Active.into(),
+            },
+            NodeMeta {
+                id: 3,
+                address: "127.0.0.1:8082".to_string(),
+                role: follower_role,
+                status: NodeStatus::Active.into(),
+            },
+        ]
+    };
+
+    let (_graceful_tx, _graceful_rx) = watch::channel(());
+
+    // Each unit test db path will be different
+    let mut node_config = RaftNodeConfig::default();
+    node_config.cluster.db_root_dir = PathBuf::from(db_path);
+    node_config.cluster.initial_cluster = peers_meta.clone();
+
+    let snapshot_policy = LogSizePolicy::new(
+        node_config.raft.snapshot.max_log_entries_before_snapshot,
+        node_config.raft.snapshot.snapshot_cool_down_since_last_check,
+    );
+
+    let state_machine = Arc::new(mock_state_machine);
+    let state_machine_handler = DefaultStateMachineHandler::new(
+        id,
+        last_applied_pair.index,
+        node_config.raft.commit_handler.max_entries_per_chunk,
+        state_machine.clone(),
+        node_config.raft.snapshot.clone(),
+        snapshot_policy,
+    );
+
+    let node_config_clone = node_config.clone();
+    let arc_node_config = Arc::new(node_config);
+
+    TestContext::<RaftTypeConfig<FileStorageEngine, MockStateMachine>> {
+        id,
+        raft_log: buffered_raft_log,
+        state_machine,
+        transport: Arc::new(grpc_transport),
+        membership: Arc::new(RaftMembership::new(
+            id,
+            arc_node_config.cluster.initial_cluster.clone(),
+            node_config_clone.clone(),
+        )),
+        election_handler: ElectionHandler::new(id),
+        replication_handler: ReplicationHandler::new(id),
+        node_config: node_config_clone,
+        arc_node_config,
+        state_machine_handler,
+    }
+}
+
+/// Inserts entries into the Raft log with specified IDs and term.
+///
+/// Creates insert command entries and appends them to the Raft log storage.
+/// Each ID becomes a separate log entry with the given term.
+///
+/// # Arguments
+///
+/// * `raft_log` - Reference to the Raft log storage
+/// * `ids` - Vector of IDs to insert as separate log entries
+/// * `term` - The term for all inserted entries
+///
+/// # Panics
+///
+/// Panics if the batch insert operation fails.
+#[allow(dead_code)]
+pub(crate) async fn insert_raft_log(
+    raft_log: &Arc<ROF<RaftTypeConfig<FileStorageEngine, FileStateMachine>>>,
+    ids: Vec<u64>,
+    term: u64,
+) {
+    let mut entries = Vec::new();
+    for id in ids {
+        let log = Entry {
+            index: raft_log.pre_allocate_raft_logs_next_index(),
+            term,
+            payload: Some(EntryPayload::command(generate_insert_commands(vec![id]))),
+        };
+        entries.push(log);
+    }
+    if let Err(e) = raft_log.insert_batch(entries).await {
+        panic!("error:{e:?}");
+    }
+}
+
+/// Applies entries to the state machine with specified IDs and term.
+///
+/// Creates insert command entries and applies them directly to the state machine,
+/// simulating the application of committed log entries. Each ID becomes a separate
+/// entry with the given term.
+///
+/// # Arguments
+///
+/// * `state_machine` - Reference to the state machine
+/// * `ids` - Vector of IDs to insert as separate entries
+/// * `term` - The term for all inserted entries
+///
+/// # Panics
+///
+/// Panics if the chunk application operation fails.
+#[allow(dead_code)]
+pub(crate) async fn insert_state_machine(
+    state_machine: &SMOF<RaftTypeConfig<FileStorageEngine, FileStateMachine>>,
+    ids: Vec<u64>,
+    term: u64,
+) {
+    let mut entries = Vec::new();
+    for id in ids {
+        let log = Entry {
+            index: id,
+            term,
+            payload: Some(EntryPayload::command(generate_insert_commands(vec![id]))),
+        };
+        entries.push(log);
+    }
+    if let Err(e) = state_machine.apply_chunk(entries).await {
+        panic!("error: {e:?}");
+    }
+}
+
+/// Simulates inserting commands into the Raft log with automatic log entry allocation.
+///
+/// Creates insert command entries and appends them to the Raft log storage, then
+/// flushes the log to ensure durability. The log entry indices are automatically
+/// allocated by the Raft log, not specified externally.
+///
+/// # Arguments
+///
+/// * `raft_log` - Reference to the Raft log storage
+/// * `ids` - Vector of IDs to insert as separate commands
+/// * `term` - The term for all inserted entries
+///
+/// # Panics
+///
+/// Panics if the batch insert or flush operation fails.
+///
+/// # Note
+///
+/// If duplicate IDs are specified, only one entry per ID will be inserted due to
+/// the internal command generation logic.
+pub async fn simulate_insert_command(
+    raft_log: &Arc<ROF<RaftTypeConfig<FileStorageEngine, MockStateMachine>>>,
+    ids: Vec<u64>,
+    term: u64,
+) {
+    let mut entries = Vec::new();
+    for id in ids {
+        let log = Entry {
+            index: raft_log.pre_allocate_raft_logs_next_index(),
+            term,
+            payload: Some(EntryPayload::command(generate_insert_commands(vec![id]))),
+        };
+        entries.push(log);
+    }
+    raft_log.insert_batch(entries).await.unwrap();
+    raft_log.flush().await.unwrap();
+}
+
+/// Simulates deleting entries from the log for a range of IDs.
+///
+/// Creates delete command entries for each ID in the specified range and appends
+/// them to the Raft log storage. Each ID in the range becomes a separate delete
+/// command entry with the given term.
+///
+/// # Arguments
+///
+/// * `raft_log` - Reference to the Raft log storage
+/// * `id_range` - An inclusive range of IDs to delete
+/// * `term` - The term for all delete entries
+///
+/// # Panics
+///
+/// Panics if the batch insert operation fails.
+#[allow(dead_code)]
+pub async fn simulate_delete_command(
+    raft_log: &Arc<ROF<RaftTypeConfig<FileStorageEngine, MockStateMachine>>>,
+    id_range: RangeInclusive<u64>,
+    term: u64,
+) {
+    let mut entries = Vec::new();
+    for id in id_range {
+        let log = Entry {
+            index: raft_log.pre_allocate_raft_logs_next_index(),
+            term,
+            payload: Some(EntryPayload::command(generate_delete_commands(id..=id))),
+        };
+        entries.push(log);
+    }
+    if let Err(e) = raft_log.insert_batch(entries).await {
+        panic!("error: {e:?}");
+    }
+}
diff --git a/d-engine-server/src/test_utils/mock/mock_node_builder.rs b/d-engine-server/src/test_utils/mock/mock_node_builder.rs
new file mode 100644
index 00000000..11d140c9
--- /dev/null
+++ b/d-engine-server/src/test_utils/mock/mock_node_builder.rs
@@ -0,0 +1,587 @@
+//! Mock node builder for fluent configuration of test Raft instances
+
+use std::path::Path;
+use std::sync::Arc;
+use std::sync::atomic::AtomicBool;
+
+use bytes::Bytes;
+use tokio::sync::Mutex;
+use tokio::sync::mpsc;
+use tokio::sync::watch;
+use tracing::error;
+use tracing::trace;
+
+use super::MockTypeConfig;
+use crate::Node;
+use crate::network::grpc;
+use d_engine_core::ElectionConfig;
+use d_engine_core::MockElectionCore;
+use d_engine_core::MockMembership;
+use d_engine_core::MockPurgeExecutor;
+use d_engine_core::MockRaftLog;
+use d_engine_core::MockReplicationCore;
+use d_engine_core::MockStateMachine;
+use d_engine_core::MockStateMachineHandler;
+use d_engine_core::MockTransport;
+use d_engine_core::Raft;
+use d_engine_core::RaftConfig;
+use d_engine_core::RaftContext;
+use d_engine_core::RaftCoreHandlers;
+use d_engine_core::RaftEvent;
+use d_engine_core::RaftLog;
+use d_engine_core::RaftNodeConfig;
+use d_engine_core::RaftRole;
+use d_engine_core::RaftStorageHandles;
+use d_engine_core::RoleEvent;
+use d_engine_core::SignalParams;
+use d_engine_core::StateMachine;
+use d_engine_core::follower_state::FollowerState;
+use d_engine_proto::common::LogId;
+use d_engine_proto::server::cluster::ClusterMembership;
+
+/// Builder for constructing mock Raft components with customizable defaults
+///
+/// This builder provides a fluent API for creating test fixtures with
+/// fine-grained control over individual Raft components.
+///
+/// # Example: Basic Usage
+///
+/// ```rust,ignore
+/// use d_engine_server::test_utils::MockBuilder;
+/// use tokio::sync::watch;
+///
+/// let (tx, rx) = watch::channel(());
+/// let raft = MockBuilder::new(rx)
+///     .id(1)
+///     .build_raft();
+/// ```
+///
+/// # Example: Custom Configuration
+///
+/// ```rust,ignore
+/// use d_engine_server::test_utils::MockBuilder;
+/// use tokio::sync::watch;
+///
+/// let (tx, rx) = watch::channel(());
+/// let node = MockBuilder::new(rx)
+///     .id(2)
+///     .with_db_path("/tmp/test")
+///     .turn_on_election(false)
+///     .build_node();
+/// ```
+///
+/// # Builder Methods
+///
+/// - `id()` - Set node ID
+/// - `with_role()` - Set custom Raft role
+/// - `with_raft_log()` - Use custom log implementation
+/// - `with_state_machine()` - Use custom state machine
+/// - `with_transport()` - Use custom transport
+/// - `with_membership()` - Use custom membership handler
+/// - `turn_on_election()` - Enable/disable election
+///
+/// # Building Variants
+///
+/// - `build_context()` - Build RaftContext only
+/// - `build_raft()` - Build Raft instance (most common)
+/// - `build_node()` - Build Node wrapper
+/// - `build_node_with_rpc_server()` - Build Node with gRPC server
+pub struct MockBuilder {
+    /// Optional node ID (defaults to 1)
+    pub id: Option<u32>,
+    /// Optional initial Raft role
+    pub role: Option<RaftRole<MockTypeConfig>>,
+    /// Optional Raft log implementation
+    pub raft_log: Option<MockRaftLog>,
+    /// Optional state machine implementation
+    pub state_machine: Option<Arc<MockStateMachine>>,
+    /// Optional network transport
+    pub transport: Option<MockTransport<MockTypeConfig>>,
+    /// Optional membership handler
+    pub membership: Option<Arc<MockMembership<MockTypeConfig>>>,
+    /// Optional purge executor
+    pub purge_executor: Option<MockPurgeExecutor>,
+    /// Optional election handler
+    pub election_handler: Option<MockElectionCore<MockTypeConfig>>,
+    /// Optional replication handler
+    pub replication_handler: Option<MockReplicationCore<MockTypeConfig>>,
+    /// Optional state machine handler
+    pub state_machine_handler: Option<Arc<MockStateMachineHandler<MockTypeConfig>>>,
+    /// Optional node configuration
+    pub node_config: Option<RaftNodeConfig>,
+    /// Optional election toggle (defaults to true)
+    pub turn_on_election: Option<bool>,
+    /// Shutdown signal for the Raft instance
+    shutdown_signal: watch::Receiver<()>,
+
+    /// Internal event channel sender
+    pub(crate) event_tx: Option<mpsc::Sender<RaftEvent>>,
+    /// Internal event channel receiver
+    pub(crate) event_rx: Option<mpsc::Receiver<RaftEvent>>,
+
+    /// Internal role change channel sender
+    pub(crate) role_tx: Option<mpsc::UnboundedSender<RoleEvent>>,
+    /// Internal role change channel receiver
+    pub(crate) role_rx: Option<mpsc::UnboundedReceiver<RoleEvent>>,
+}
+
+impl MockBuilder {
+    /// Create a new MockBuilder with default components
+    ///
+    /// All components are initially `None`, and will use mock defaults
+    /// when building unless explicitly set.
+    ///
+    /// # Arguments
+    ///
+    /// * `shutdown_signal` - Watch receiver for graceful shutdown
+    pub fn new(shutdown_signal: watch::Receiver<()>) -> Self {
+        Self {
+            id: None,
+            role: None,
+            raft_log: None,
+            state_machine: None,
+            transport: None,
+            membership: None,
+            purge_executor: None,
+            election_handler: None,
+            replication_handler: None,
+            state_machine_handler: None,
+            node_config: None,
+            turn_on_election: None,
+            shutdown_signal,
+
+            role_tx: None,
+            role_rx: None,
+            event_tx: None,
+            event_rx: None,
+        }
+    }
+
+    /// Build a RaftContext with current configuration
+    ///
+    /// Returns the low-level Raft context for testing protocol logic.
+    pub fn build_context(self) -> RaftContext<MockTypeConfig> {
+        let (
+            raft_log,
+            state_machine,
+            transport,
+            election_handler,
+            replication_handler,
+            state_machine_handler,
+            membership,
+            purge_executor,
+            node_config,
+        ) = (
+            Arc::new(self.raft_log.unwrap_or_else(mock_raft_log)),
+            self.state_machine.unwrap_or_else(|| Arc::new(mock_state_machine())),
+            Arc::new(self.transport.unwrap_or_else(mock_transport)),
+            self.election_handler.unwrap_or_else(mock_election_core),
+            self.replication_handler.unwrap_or_else(mock_replication_handler),
+            self.state_machine_handler
+                .unwrap_or_else(|| Arc::new(mock_state_machine_handler())),
+            self.membership.unwrap_or_else(|| Arc::new(mock_membership())),
+            self.purge_executor.unwrap_or_else(mock_purge_exewcutor),
+            self.node_config.unwrap_or_else(|| {
+                RaftNodeConfig::new().expect("Should succeed to init RaftNodeConfig")
+            }),
+        );
+
+        let storage = RaftStorageHandles {
+            raft_log,
+            state_machine,
+        };
+        let handlers = RaftCoreHandlers {
+            election_handler,
+            replication_handler,
+            state_machine_handler,
+            purge_executor: Arc::new(purge_executor),
+        };
+        mock_raft_context_internal(1, storage, transport, membership, handlers, node_config)
+    }
+
+    /// Build a Raft instance with current configuration
+    ///
+    /// This is the most commonly used build method. Returns a fully
+    /// initialized Raft instance ready for testing.
+    pub fn build_raft(self) -> Raft<MockTypeConfig> {
+        let (role_tx, role_rx) = mpsc::unbounded_channel();
+        let (event_tx, event_rx) = mpsc::channel(10);
+        let (
+            id,
+            raft_log,
+            state_machine,
+            transport,
+            election_handler,
+            replication_handler,
+            state_machine_handler,
+            membership,
+            purge_executor,
+            node_config,
+            role_tx,
+            role_rx,
+            event_tx,
+            event_rx,
+        ) = (
+            self.id.unwrap_or(1),
+            self.raft_log.unwrap_or_else(mock_raft_log),
+            self.state_machine.unwrap_or_else(|| Arc::new(mock_state_machine())),
+            self.transport.unwrap_or_else(mock_transport),
+            self.election_handler.unwrap_or_else(mock_election_core),
+            self.replication_handler.unwrap_or_else(mock_replication_handler),
+            self.state_machine_handler
+                .unwrap_or_else(|| Arc::new(mock_state_machine_handler())),
+            self.membership.unwrap_or_else(|| Arc::new(mock_membership())),
+            self.purge_executor.unwrap_or_else(mock_purge_exewcutor),
+            self.node_config.unwrap_or_else(|| {
+                RaftNodeConfig::new().expect("Should succeed to init RaftNodeConfig")
+            }),
+            self.role_tx.unwrap_or(role_tx),
+            self.role_rx.unwrap_or(role_rx),
+            self.event_tx.unwrap_or(event_tx),
+            self.event_rx.unwrap_or(event_rx),
+        );
+        trace!(node_config.raft.election.election_timeout_min, "build_raft");
+
+        let election_config = {
+            if self.turn_on_election.unwrap_or(true) {
+                ElectionConfig {
+                    election_timeout_min: 1,
+                    election_timeout_max: 2,
+                    ..node_config.raft.election
+                }
+            } else {
+                node_config.raft.election
+            }
+        };
+        let arc_node_config = Arc::new(RaftNodeConfig {
+            raft: RaftConfig {
+                election: election_config,
+                ..node_config.raft
+            },
+            ..node_config
+        });
+
+        let role = self.role.unwrap_or(RaftRole::Follower(Box::new(FollowerState::new(
+            id,
+            arc_node_config.clone(),
+            raft_log.load_hard_state().expect("Failed to load hard state"),
+            Some(state_machine.last_applied().index),
+        ))));
+
+        Raft::new(
+            id,
+            role,
+            RaftStorageHandles::<MockTypeConfig> {
+                raft_log: Arc::new(raft_log),
+                state_machine,
+            },
+            transport,
+            RaftCoreHandlers::<MockTypeConfig> {
+                election_handler,
+                replication_handler,
+                state_machine_handler,
+                purge_executor: Arc::new(purge_executor),
+            },
+            membership,
+            SignalParams::new(role_tx, role_rx, event_tx, event_rx, self.shutdown_signal),
+            arc_node_config.clone(),
+        )
+    }
+
+    /// Build a Node instance (without RPC server)
+    ///
+    /// Wraps the Raft instance in a Node container for integration testing.
+    pub fn build_node(self) -> Node<MockTypeConfig> {
+        let raft = self.build_raft();
+        let event_tx = raft.event_sender();
+        let node_config = raft.ctx.node_config.clone();
+        let membership = raft.ctx.membership.clone();
+        Node::<MockTypeConfig> {
+            node_id: raft.node_id,
+            raft_core: Arc::new(Mutex::new(raft)),
+            membership,
+            event_tx,
+            ready: AtomicBool::new(false),
+            node_config,
+        }
+    }
+
+    /// Build a Node instance with integrated gRPC server
+    ///
+    /// This variant starts the RPC server in a background task,
+    /// useful for end-to-end testing with network communication.
+    pub fn build_node_with_rpc_server(self) -> Arc<Node<MockTypeConfig>> {
+        let shutdown = self.shutdown_signal.clone();
+        let node_config_option = self.node_config.clone();
+
+        let raft = self.build_raft();
+        let event_tx = raft.event_sender();
+        let node_config = node_config_option.unwrap_or_else(|| {
+            RaftNodeConfig::new().expect("Should succeed to init RaftNodeConfig")
+        });
+        let membership = raft.ctx.membership.clone();
+        trace!(
+            node_config.raft.election.election_timeout_min,
+            "build_node_with_rpc_server"
+        );
+        let node = Arc::new(Node::<MockTypeConfig> {
+            node_id: raft.node_id,
+            raft_core: Arc::new(Mutex::new(raft)),
+            membership,
+            event_tx,
+            ready: AtomicBool::new(false),
+            node_config: Arc::new(node_config.clone()),
+        });
+        let node_clone = node.clone();
+        let listen_address = node_config.cluster.listen_address;
+        let node_config = node_config.clone();
+        tokio::spawn(async move {
+            if let Err(e) =
+                grpc::start_rpc_server(node_clone, listen_address, node_config, shutdown).await
+            {
+                eprintln!("RPC server stops. {e:?}");
+                error!("RPC server stops. {e:?}");
+            }
+        });
+
+        node
+    }
+
+    /// Set the node ID (defaults to 1)
+    pub fn id(
+        mut self,
+        id: u32,
+    ) -> Self {
+        self.id = Some(id);
+        self
+    }
+
+    /// Set a custom initial Raft role
+    pub fn with_role(
+        mut self,
+        role: RaftRole<MockTypeConfig>,
+    ) -> Self {
+        self.role = Some(role);
+        self
+    }
+
+    /// Set a custom Raft log implementation
+    pub fn with_raft_log(
+        mut self,
+        raft_log: MockRaftLog,
+    ) -> Self {
+        self.raft_log = Some(raft_log);
+        self
+    }
+
+    /// Set a custom state machine implementation
+    pub fn with_state_machine(
+        mut self,
+        sm: MockStateMachine,
+    ) -> Self {
+        self.state_machine = Some(Arc::new(sm));
+        self
+    }
+
+    /// Set a custom network transport
+    pub fn with_transport(
+        mut self,
+        transport: MockTransport<MockTypeConfig>,
+    ) -> Self {
+        self.transport = Some(transport);
+        self
+    }
+
+    /// Set a custom membership handler
+    pub fn with_membership(
+        mut self,
+        membership: MockMembership<MockTypeConfig>,
+    ) -> Self {
+        self.membership = Some(Arc::new(membership));
+        self
+    }
+
+    /// Set a custom election handler
+    pub fn with_election_handler(
+        mut self,
+        election_handler: MockElectionCore<MockTypeConfig>,
+    ) -> Self {
+        self.election_handler = Some(election_handler);
+        self
+    }
+
+    /// Set a custom replication handler
+    pub fn with_replication_handler(
+        mut self,
+        replication_handler: MockReplicationCore<MockTypeConfig>,
+    ) -> Self {
+        self.replication_handler = Some(replication_handler);
+        self
+    }
+
+    /// Set a custom state machine handler
+    pub fn with_state_machine_handler(
+        mut self,
+        state_machine_handler: MockStateMachineHandler<MockTypeConfig>,
+    ) -> Self {
+        self.state_machine_handler = Some(Arc::new(state_machine_handler));
+        self
+    }
+
+    /// Set custom node configuration
+    pub fn with_node_config(
+        mut self,
+        node_config: RaftNodeConfig,
+    ) -> Self {
+        self.node_config = Some(node_config);
+        self
+    }
+
+    /// Set the database root directory path
+    ///
+    /// Automatically updates the node configuration with the provided path.
+    pub fn with_db_path(
+        mut self,
+        db_root_dir: impl AsRef<Path>,
+    ) -> Self {
+        let mut node_config =
+            RaftNodeConfig::new().expect("Should succeed to init RaftNodeConfig.");
+        node_config.cluster.db_root_dir = db_root_dir.as_ref().to_path_buf();
+        self.node_config = Some(node_config);
+        self
+    }
+
+    /// Enable or disable election handling (defaults to enabled)
+    ///
+    /// Set to `false` to prevent automatic elections during testing.
+    pub fn turn_on_election(
+        mut self,
+        is_on: bool,
+    ) -> Self {
+        self.turn_on_election = Some(is_on);
+        self
+    }
+}
+
+// ==================== Mock Factory Functions ====================
+
+/// Create a mock Raft log with sensible test defaults
+pub(crate) fn mock_raft_log() -> MockRaftLog {
+    let mut raft_log = MockRaftLog::new();
+    raft_log.expect_last_entry_id().returning(|| 0);
+    raft_log.expect_last_log_id().returning(|| None);
+    raft_log.expect_flush().returning(|| Ok(()));
+    raft_log.expect_load_hard_state().returning(|| Ok(None));
+    raft_log.expect_save_hard_state().returning(|_| Ok(()));
+    raft_log
+}
+
+/// Create a mock network transport
+pub(crate) fn mock_transport() -> MockTransport<MockTypeConfig> {
+    MockTransport::new()
+}
+
+/// Create a mock election handler
+pub(crate) fn mock_election_core() -> MockElectionCore<MockTypeConfig> {
+    let mut election_handler = MockElectionCore::new();
+    election_handler
+        .expect_broadcast_vote_requests()
+        .returning(|_, _, _, _, _| Ok(()));
+    election_handler
+}
+
+/// Create a mock replication handler
+pub(crate) fn mock_replication_handler() -> MockReplicationCore<MockTypeConfig> {
+    MockReplicationCore::new()
+}
+
+/// Create a mock state machine with all methods stubbed
+pub(crate) fn mock_state_machine() -> MockStateMachine {
+    let mut mock = MockStateMachine::new();
+
+    mock.expect_start().returning(|| Ok(()));
+    mock.expect_stop().returning(|| Ok(()));
+    mock.expect_is_running().returning(|| true);
+
+    mock.expect_get().returning(|_| Ok(None));
+    mock.expect_entry_term().returning(|_| None);
+    mock.expect_apply_chunk().returning(|_| Ok(()));
+    mock.expect_len().returning(|| 0);
+
+    mock.expect_update_last_applied().returning(|_| ());
+    mock.expect_last_applied().return_const(LogId::default());
+    mock.expect_persist_last_applied().returning(|_| Ok(()));
+
+    mock.expect_update_last_snapshot_metadata().returning(|_| Ok(()));
+    mock.expect_snapshot_metadata().returning(|| None);
+    mock.expect_persist_last_snapshot_metadata().returning(|_| Ok(()));
+
+    mock.expect_apply_snapshot_from_file().returning(|_, _| Ok(()));
+    mock.expect_generate_snapshot_data()
+        .returning(|_, _| Ok(Bytes::copy_from_slice(&[0u8; 32])));
+
+    mock.expect_save_hard_state().returning(|| Ok(()));
+    mock.expect_flush().returning(|| Ok(()));
+
+    mock
+}
+
+/// Create a mock state machine handler
+pub(crate) fn mock_state_machine_handler() -> MockStateMachineHandler<MockTypeConfig> {
+    let mut state_machine_handler = MockStateMachineHandler::new();
+    state_machine_handler.expect_update_pending().returning(|_| {});
+    state_machine_handler.expect_read_from_state_machine().returning(|_| None);
+    state_machine_handler
+}
+
+/// Create a mock purge executor
+pub(crate) fn mock_purge_exewcutor() -> MockPurgeExecutor {
+    let mut purge_exewcutor = MockPurgeExecutor::new();
+    purge_exewcutor.expect_execute_purge().returning(|_| Ok(()));
+    purge_exewcutor
+}
+
+/// Create a mock membership handler
+pub(crate) fn mock_membership() -> MockMembership<MockTypeConfig> {
+    let mut membership = MockMembership::new();
+    membership.expect_can_rejoin().returning(|_, _| Ok(()));
+    membership.expect_pre_warm_connections().returning(|| Ok(()));
+    membership.expect_voters().returning(Vec::new);
+    membership.expect_replication_peers().returning(Vec::new);
+    membership.expect_members().returning(Vec::new);
+    membership.expect_reset_leader().returning(|| Ok(()));
+    membership.expect_update_node_role().returning(|_, _| Ok(()));
+    membership.expect_mark_leader_id().returning(|_| Ok(()));
+    membership.expect_check_cluster_is_ready().returning(|| Ok(()));
+    membership
+        .expect_retrieve_cluster_membership_config()
+        .returning(|| ClusterMembership {
+            version: 1,
+            nodes: vec![],
+        });
+    membership.expect_get_zombie_candidates().returning(Vec::new);
+    membership.expect_get_peers_id_with_condition().returning(|_| vec![]);
+    membership
+}
+
+/// Create a RaftContext with mock components
+pub(crate) fn mock_raft_context_internal(
+    id: u32,
+    storage: RaftStorageHandles<MockTypeConfig>,
+    transport: Arc<MockTransport<MockTypeConfig>>,
+    membership: Arc<MockMembership<MockTypeConfig>>,
+    handlers: RaftCoreHandlers<MockTypeConfig>,
+    node_config: RaftNodeConfig,
+) -> RaftContext<MockTypeConfig> {
+    RaftContext {
+        node_id: id,
+        storage,
+
+        transport,
+        membership,
+
+        handlers,
+
+        node_config: Arc::new(node_config),
+    }
+}
diff --git a/d-engine-server/src/test_utils/mock/mod.rs b/d-engine-server/src/test_utils/mock/mod.rs
new file mode 100644
index 00000000..0a443af6
--- /dev/null
+++ b/d-engine-server/src/test_utils/mock/mod.rs
@@ -0,0 +1,87 @@
+//! Mock implementations for Raft components
+//!
+//! Provides convenient builders and factory functions for creating
+//! mock Raft instances with sensible defaults.
+
+mod mock_node_builder;
+
+pub use mock_node_builder::*;
+
+use crate::Node;
+use d_engine_core::node_config;
+use d_engine_core::{MockTypeConfig, Raft};
+use d_engine_proto::server::cluster::NodeMeta;
+use tokio::sync::watch;
+
+/// Create a mock Raft node for testing
+///
+/// Constructs a Node instance with mock components and optional peer metadata.
+///
+/// # Arguments
+///
+/// * `db_path` - Path for database configuration
+/// * `shutdown_signal` - Watch receiver for graceful shutdown
+/// * `peers_meta_option` - Optional list of peer node metadata
+///
+/// # Example
+///
+/// ```rust,ignore
+/// use d_engine_server::test_utils::mock_node;
+/// use tokio::sync::watch;
+///
+/// let (tx, rx) = watch::channel(());
+/// let node = mock_node("/tmp/test_db", rx, None);
+/// ```
+pub fn mock_node(
+    db_path: &str,
+    shutdown_signal: watch::Receiver<()>,
+    peers_meta_option: Option<Vec<NodeMeta>>,
+) -> Node<MockTypeConfig> {
+    let mut node_config = node_config(db_path);
+    if let Some(peers_meta) = peers_meta_option {
+        node_config.cluster.initial_cluster = peers_meta;
+    }
+    // Initializing Shutdown Signal
+    // let (graceful_tx, graceful_rx) = watch::channel(());
+    MockBuilder::new(shutdown_signal).with_node_config(node_config).build_node()
+}
+
+/// Create a mock Raft instance for testing
+///
+/// Constructs a Raft instance with all components mocked and optimized
+/// for testing (e.g., batch threshold set to 0 for immediate replication).
+///
+/// # Arguments
+///
+/// * `db_path` - Path for database configuration
+/// * `shutdown_signal` - Watch receiver for graceful shutdown
+/// * `peers_meta_option` - Optional list of peer node metadata
+///
+/// # Example
+///
+/// ```rust,ignore
+/// use d_engine_server::test_utils::mock_raft;
+/// use tokio::sync::watch;
+///
+/// let (tx, rx) = watch::channel(());
+/// let raft = mock_raft("/tmp/test_db", rx, None);
+/// ```
+///
+/// # Note
+///
+/// This sets `rpc_append_entries_in_batch_threshold=0` to ensure
+/// replication happens immediately (useful for testing).
+pub fn mock_raft(
+    db_path: &str,
+    shutdown_signal: watch::Receiver<()>,
+    peers_meta_option: Option<Vec<NodeMeta>>,
+) -> Raft<MockTypeConfig> {
+    let mut node_config = node_config(db_path);
+    // Set batch_threshold=0, means the replication will be triggered immediatelly.
+    node_config.raft.replication.rpc_append_entries_in_batch_threshold = 0;
+    if let Some(peers_meta) = peers_meta_option {
+        node_config.cluster.initial_cluster = peers_meta;
+    }
+
+    MockBuilder::new(shutdown_signal).with_node_config(node_config).build_raft()
+}
diff --git a/d-engine-server/src/test_utils/mod.rs b/d-engine-server/src/test_utils/mod.rs
new file mode 100644
index 00000000..c60bc263
--- /dev/null
+++ b/d-engine-server/src/test_utils/mod.rs
@@ -0,0 +1,28 @@
+//! Test utilities and mock implementations
+//!
+//! This module provides builders and fixtures for testing d-engine-server.
+//!
+//! # Features
+//!
+//! - **Mock Builder**: Easily construct mock Raft instances with custom components
+//! - **Integration Helpers**: Utilities for integration testing
+//!
+//! # Example
+//!
+//! ```rust,ignore
+//! use d_engine_server::test_utils::MockBuilder;
+//! use tokio::sync::watch;
+//!
+//! let (tx, rx) = watch::channel(());
+//! let mock_raft = MockBuilder::new(rx).build_raft();
+//! ```
+//!
+//! # Note
+//!
+//! This module is only available with the `test-utils` feature or during tests.
+
+mod integration;
+mod mock;
+
+pub use integration::*;
+pub use mock::*;
diff --git a/src/utils/async_task.rs b/d-engine-server/src/utils/async_task.rs
similarity index 96%
rename from src/utils/async_task.rs
rename to d-engine-server/src/utils/async_task.rs
index 9188efa5..d2862c95 100644
--- a/src/utils/async_task.rs
+++ b/d-engine-server/src/utils/async_task.rs
@@ -6,9 +6,9 @@ use tracing::debug;
 use tracing::error;
 use tracing::warn;
 
-use crate::BackoffPolicy;
-use crate::NetworkError;
-use crate::Result;
+use d_engine_core::BackoffPolicy;
+use d_engine_core::NetworkError;
+use d_engine_core::Result;
 
 /// General one
 pub(crate) async fn task_with_timeout_and_exponential_backoff<F, T, P>(
diff --git a/src/utils/async_task_test.rs b/d-engine-server/src/utils/async_task_test.rs
similarity index 95%
rename from src/utils/async_task_test.rs
rename to d-engine-server/src/utils/async_task_test.rs
index 92efded4..fdad5cdc 100644
--- a/src/utils/async_task_test.rs
+++ b/d-engine-server/src/utils/async_task_test.rs
@@ -1,15 +1,13 @@
+use super::async_task::*;
+
+use d_engine_core::BackoffPolicy;
+use d_engine_core::Error;
+use futures::future::join_all;
+use std::sync::Arc;
 use std::sync::atomic::AtomicU32;
 use std::sync::atomic::Ordering;
-use std::sync::Arc;
 use std::time::Duration;
 
-use futures::future::join_all;
-
-use crate::async_task::spawn_task;
-use crate::async_task::task_with_timeout_and_exponential_backoff;
-use crate::BackoffPolicy;
-use crate::Error;
-
 #[tokio::test]
 async fn test_task_with_timeout_and_exponential_backoff_success() {
     let counter = Arc::new(AtomicU32::new(0));
@@ -22,7 +20,7 @@ async fn test_task_with_timeout_and_exponential_backoff_success() {
             if current == 0 {
                 Err(Error::Fatal("First attempt fails".to_string()))
             } else {
-                Ok::<_, crate::Error>(current)
+                Ok::<_, d_engine_core::Error>(current)
             }
         }
     };
diff --git a/src/utils/cluster.rs b/d-engine-server/src/utils/cluster.rs
similarity index 82%
rename from src/utils/cluster.rs
rename to d-engine-server/src/utils/cluster.rs
index ff0b5f2e..ce6615a6 100644
--- a/src/utils/cluster.rs
+++ b/d-engine-server/src/utils/cluster.rs
@@ -6,11 +6,11 @@ use dashmap::DashSet;
 use metrics::gauge;
 use tracing::error;
 
-use crate::proto::common::Entry;
-use crate::CANDIDATE;
-use crate::FOLLOWER;
-use crate::LEADER;
-use crate::LEARNER;
+use d_engine_proto::common::Entry;
+use d_engine_proto::common::NodeRole::Candidate;
+use d_engine_proto::common::NodeRole::Follower;
+use d_engine_proto::common::NodeRole::Leader;
+use d_engine_proto::common::NodeRole::Learner;
 
 pub(crate) fn collect_ids(entries: &[Entry]) -> Vec<u64> {
     entries.iter().map(|e| e.index).collect()
@@ -64,20 +64,20 @@ pub fn error(
 
 #[inline]
 pub fn is_follower(role_i32: i32) -> bool {
-    role_i32 == FOLLOWER
+    role_i32 == Follower.into()
 }
 
 #[inline]
 pub fn is_candidate(role_i32: i32) -> bool {
-    role_i32 == CANDIDATE
+    role_i32 == Candidate.into()
 }
 
 #[inline]
 pub fn is_leader(role_i32: i32) -> bool {
-    role_i32 == LEADER
+    role_i32 == Leader.into()
 }
 
 #[inline]
 pub fn is_learner(role_i32: i32) -> bool {
-    role_i32 == LEARNER
+    role_i32 == Learner.into()
 }
diff --git a/d-engine-server/src/utils/mod.rs b/d-engine-server/src/utils/mod.rs
new file mode 100644
index 00000000..b87233e6
--- /dev/null
+++ b/d-engine-server/src/utils/mod.rs
@@ -0,0 +1,17 @@
+#[allow(dead_code)]
+pub mod async_task;
+
+#[allow(dead_code)]
+pub mod cluster;
+
+#[allow(dead_code)]
+pub mod net;
+
+#[cfg(test)]
+mod utils_test;
+
+#[cfg(test)]
+mod async_task_test;
+
+#[cfg(test)]
+mod net_test;
diff --git a/src/utils/net.rs b/d-engine-server/src/utils/net.rs
similarity index 100%
rename from src/utils/net.rs
rename to d-engine-server/src/utils/net.rs
diff --git a/src/utils/net_test.rs b/d-engine-server/src/utils/net_test.rs
similarity index 94%
rename from src/utils/net_test.rs
rename to d-engine-server/src/utils/net_test.rs
index ef207598..332f1a02 100644
--- a/src/utils/net_test.rs
+++ b/d-engine-server/src/utils/net_test.rs
@@ -1,4 +1,4 @@
-use crate::net::address_str;
+use super::net::*;
 
 #[test]
 fn test_address_str() {
diff --git a/d-engine-server/src/utils/scoped_timer.rs b/d-engine-server/src/utils/scoped_timer.rs
new file mode 100644
index 00000000..b2a80820
--- /dev/null
+++ b/d-engine-server/src/utils/scoped_timer.rs
@@ -0,0 +1,23 @@
+use tokio::time::Instant;
+use tracing::debug;
+
+pub(crate) struct ScopedTimer {
+    start: Instant,
+    name: &'static str,
+}
+
+impl ScopedTimer {
+    pub(crate) fn new(name: &'static str) -> Self {
+        Self {
+            start: Instant::now(),
+            name,
+        }
+    }
+}
+
+impl Drop for ScopedTimer {
+    fn drop(&mut self) {
+        let elapsed = self.start.elapsed();
+        debug!(target: "timing", "[TIMING] {} took {} ms", self.name, elapsed.as_millis());
+    }
+}
diff --git a/src/utils/utils_test.rs b/d-engine-server/src/utils/utils_test.rs
similarity index 91%
rename from src/utils/utils_test.rs
rename to d-engine-server/src/utils/utils_test.rs
index 619b195e..452eb3dd 100644
--- a/src/utils/utils_test.rs
+++ b/d-engine-server/src/utils/utils_test.rs
@@ -5,15 +5,15 @@ use dashmap::DashSet;
 use tokio::time::sleep;
 use tracing_test::traced_test;
 
+use super::async_task::*;
 use super::cluster::find_nearest_lower_number;
-use crate::async_task::task_with_timeout_and_exponential_backoff;
-use crate::convert::abs_ceil;
-use crate::convert::safe_kv;
-use crate::convert::safe_vk;
 use crate::utils::cluster::is_majority;
-use crate::BackoffPolicy;
-use crate::NetworkError;
-use crate::Result;
+use d_engine_core::BackoffPolicy;
+use d_engine_core::NetworkError;
+use d_engine_core::Result;
+use d_engine_core::convert::abs_ceil;
+use d_engine_core::convert::safe_kv;
+use d_engine_core::convert::safe_vk;
 
 #[test]
 fn test_kv_1() {
diff --git a/d-engine-server/tests/components/buffered_raft_log_test.rs b/d-engine-server/tests/components/buffered_raft_log_test.rs
new file mode 100644
index 00000000..24800e1b
--- /dev/null
+++ b/d-engine-server/tests/components/buffered_raft_log_test.rs
@@ -0,0 +1,4590 @@
+use bytes::Bytes;
+use futures::future::join_all;
+use std::collections::HashMap;
+use std::path::PathBuf;
+use std::sync::Arc;
+use std::sync::atomic::AtomicBool;
+use std::sync::atomic::Ordering;
+use std::time::Duration;
+use std::vec;
+use tempfile::tempdir;
+use tokio::time::Instant;
+use tokio::time::sleep;
+use tracing::debug;
+use tracing_test::traced_test;
+
+use d_engine_core::FlushPolicy;
+use d_engine_core::LogStore;
+use d_engine_core::MockLogStore;
+use d_engine_core::MockMetaStore;
+use d_engine_core::MockStateMachine;
+use d_engine_core::MockStorageEngine;
+use d_engine_core::MockTypeConfig;
+use d_engine_core::PersistenceConfig;
+use d_engine_core::PersistenceStrategy;
+use d_engine_core::RaftLog;
+use d_engine_core::StorageEngine;
+use d_engine_core::alias::ROF;
+use d_engine_core::test_utils::generate_insert_commands;
+use d_engine_proto::common::Entry;
+use d_engine_proto::common::EntryPayload;
+use d_engine_proto::common::LogId;
+use d_engine_server::BufferedRaftLog;
+use d_engine_server::FileStorageEngine;
+use d_engine_server::RaftTypeConfig;
+use d_engine_server::test_utils;
+
+// Test utilities
+struct TestContext {
+    raft_log: Arc<ROF<RaftTypeConfig<FileStorageEngine, MockStateMachine>>>,
+    storage: Arc<FileStorageEngine>,
+    _temp_dir: Option<tempfile::TempDir>,
+    strategy: PersistenceStrategy,
+    flush_policy: FlushPolicy,
+    // Add instance ID to ensure proper crash recovery simulation
+    path: String,
+}
+
+impl TestContext {
+    fn new(
+        strategy: PersistenceStrategy,
+        flush_policy: FlushPolicy,
+        instance_id: &str,
+    ) -> Self {
+        let temp_dir = tempdir().unwrap();
+        let path = temp_dir.path().to_path_buf().join(instance_id);
+        // let instance_id = instance_id.to_string();
+        let storage = Arc::new(FileStorageEngine::new(path.clone()).unwrap());
+
+        let (raft_log, receiver) = BufferedRaftLog::new(
+            1,
+            PersistenceConfig {
+                strategy: strategy.clone(),
+                flush_policy: flush_policy.clone(),
+                max_buffered_entries: 1000,
+                ..Default::default()
+            },
+            storage.clone(),
+        );
+        let raft_log = { raft_log.start(receiver) };
+
+        // Small delay to ensure processor is ready
+        std::thread::sleep(Duration::from_millis(10));
+
+        Self {
+            path: path.to_str().unwrap().to_string(),
+            raft_log,
+            storage,
+            strategy,
+            flush_policy,
+            _temp_dir: Some(temp_dir),
+        }
+    }
+
+    // Method to create a new context that simulates recovery from the same storage
+    fn recover_from_crash(&self) -> Self {
+        let temp_dir = tempdir().unwrap();
+
+        // Use the same instance ID to simulate recovery from the same storage
+        let storage = Arc::new(FileStorageEngine::new(PathBuf::from(self.path.clone())).unwrap());
+
+        let (raft_log, receiver) = BufferedRaftLog::new(
+            1,
+            PersistenceConfig {
+                strategy: self.strategy.clone(),
+                flush_policy: self.flush_policy.clone(),
+                max_buffered_entries: 1000,
+                ..Default::default()
+            },
+            storage.clone(),
+        );
+        let raft_log = raft_log.start(receiver);
+
+        // Small delay to ensure processor is ready
+        std::thread::sleep(Duration::from_millis(10));
+
+        Self {
+            raft_log,
+            storage,
+            strategy: self.strategy.clone(),
+            flush_policy: self.flush_policy.clone(),
+            _temp_dir: Some(temp_dir),
+            path: self.path.clone(),
+        }
+    }
+
+    async fn append_entries(
+        &self,
+        start: u64,
+        count: u64,
+        term: u64,
+    ) {
+        let entries: Vec<_> = (start..start + count)
+            .map(|index| Entry {
+                index,
+                term,
+                payload: Some(EntryPayload::command(Bytes::from(b"data".to_vec()))),
+            })
+            .collect();
+
+        self.raft_log.append_entries(entries).await.unwrap();
+    }
+}
+
+async fn insert(
+    raft_log: &Arc<ROF<RaftTypeConfig<FileStorageEngine, MockStateMachine>>>,
+    key: u64,
+) {
+    let log = Entry {
+        index: key,
+        term: 7,
+        payload: None,
+    };
+    raft_log.insert_batch(vec![log]).await.expect("should succeed");
+}
+
+#[tokio::test]
+#[traced_test]
+async fn test_get_range1() {
+    let context = TestContext::new(
+        PersistenceStrategy::MemFirst,
+        FlushPolicy::Batch {
+            threshold: 1,
+            interval_ms: 1,
+        },
+        "test_get_range1",
+    );
+    let i1: u64 = 11;
+    let i2: u64 = 12;
+    let i3: u64 = 13;
+    let i4: u64 = 14;
+    test_utils::simulate_insert_command(&context.raft_log, vec![i1, i2, i3, i4], 4).await;
+    let list = context.raft_log.get_entries_range(1..=2).unwrap();
+
+    // let mut list = Vec::<Entry>::new();
+    // for i in r {
+    //     let mut l = Entry::default();
+    //     l.unpack(&mut Cursor::new(i)).expect("unpack failed.");
+    //     list.push(l);
+    // }
+    assert_eq!(2, list.len());
+    assert_eq!(list[0].index, 1);
+    assert_eq!(list[1].index, 2);
+}
+
+#[tokio::test]
+#[traced_test]
+async fn test_get_range2() {
+    let context = TestContext::new(
+        PersistenceStrategy::MemFirst,
+        FlushPolicy::Batch {
+            threshold: 1,
+            interval_ms: 1,
+        },
+        "test_get_range2",
+    );
+
+    for i in 1..300 {
+        insert(&context.raft_log, i).await;
+    }
+
+    let list = context.raft_log.get_entries_range(255..=255).unwrap();
+
+    // let mut list = Vec::<Entry>::new();
+    // for i in r {
+    //     let mut l = Entry::default();
+    //     l.unpack(&mut Cursor::new(i)).expect("unpack failed.");
+    //     list.push(l);
+    // }
+    assert_eq!(1, list.len());
+    assert_eq!(list[0].index, 255);
+}
+
+/// # Case 1: test follower f delete conflicts (Figure 7 in raft paper)
+///
+/// ## Setup:
+/// 1. leader:log1(1), log2(1), log3(1), log4(4), log5(4), log6(5), log7(5), log8(6), log9(6),
+///    log10(6)
+///
+/// follower_f: log1(1), log2(1), log3(1), log4(2), log5(2), log6(2), log7(3), log8(3),
+///    log9(3), log10(3), log11(3)
+///
+/// ## Criterias:
+/// 1. next_id been updated to:
+///
+///   Follower    lastIndex    nextIndex
+///   follower_a      9      10
+///   follower_b      4      5
+///   follower_c      10      11
+///   follower_d      12      11
+///   follower_e      7      6
+///   follower_f      11    4
+#[tokio::test]
+#[traced_test]
+async fn test_filter_out_conflicts_and_append_case1() {
+    let context = TestContext::new(
+        PersistenceStrategy::MemFirst,
+        FlushPolicy::Batch {
+            threshold: 1,
+            interval_ms: 1,
+        },
+        "test_filter_out_conflicts_and_append_case1",
+    );
+    context.raft_log.reset().await.expect("reset successfully!");
+    test_utils::simulate_insert_command(&context.raft_log, vec![1], 1).await;
+    test_utils::simulate_insert_command(&context.raft_log, vec![2, 3], 2).await;
+    test_utils::simulate_insert_command(&context.raft_log, vec![4], 4).await;
+
+    //case 1
+    let l1 = Entry {
+        index: 2,
+        term: 2,
+        payload: None,
+    };
+    let l2 = Entry {
+        index: 3,
+        term: 3,
+        payload: None,
+    };
+    let new_ones = vec![l1, l2];
+    let prev_log_index = 1;
+    let prev_log_term = 1;
+    let last_applied = context
+        .raft_log
+        .filter_out_conflicts_and_append(prev_log_index, prev_log_term, new_ones)
+        .await
+        .unwrap()
+        .unwrap();
+    assert_eq!(last_applied.index, 3);
+
+    let e = context.raft_log.entry(3).unwrap().unwrap();
+    assert_eq!(e.term, 3);
+}
+#[tokio::test]
+#[traced_test]
+async fn test_filter_out_conflicts_and_append() {
+    let context = TestContext::new(
+        PersistenceStrategy::MemFirst,
+        FlushPolicy::Batch {
+            threshold: 1,
+            interval_ms: 1,
+        },
+        "test_filter_out_conflicts_and_append",
+    );
+    // let state = &context.s;
+    context.raft_log.reset().await.expect("reset successfully!");
+    test_utils::simulate_insert_command(&context.raft_log, vec![1], 1).await;
+    test_utils::simulate_insert_command(&context.raft_log, vec![2, 3], 2).await;
+    test_utils::simulate_insert_command(&context.raft_log, vec![4], 4).await;
+
+    //case 1
+    let l1 = Entry {
+        index: 2,
+        term: 2,
+        payload: None,
+    };
+    let l2 = Entry {
+        index: 3,
+        term: 3,
+        payload: None,
+    };
+    let new_ones = vec![l1, l2];
+    let prev_log_index = 1;
+    let prev_log_term = 1;
+    let last_applied = context
+        .raft_log
+        .filter_out_conflicts_and_append(prev_log_index, prev_log_term, new_ones)
+        .await
+        .unwrap()
+        .unwrap();
+    assert_eq!(last_applied.index, 3);
+
+    let e = context.raft_log.entry(3).unwrap().unwrap();
+    assert_eq!(e.term, 3);
+
+    //case 2
+    let l3 = Entry {
+        index: 4,
+        term: 2,
+        payload: None,
+    };
+    let new_ones = vec![l3];
+    let prev_log_index = 1;
+    let prev_log_term = 1;
+    let last_applied = context
+        .raft_log
+        .filter_out_conflicts_and_append(prev_log_index, prev_log_term, new_ones)
+        .await
+        .unwrap()
+        .unwrap();
+    assert_eq!(last_applied.index, 4);
+    let e = context.raft_log.entry(4).unwrap().unwrap();
+    assert_eq!(e.term, 2);
+}
+
+#[tokio::test]
+#[traced_test]
+async fn test_get_last_raft_log() {
+    let context = TestContext::new(
+        PersistenceStrategy::MemFirst,
+        FlushPolicy::Batch {
+            threshold: 1,
+            interval_ms: 1,
+        },
+        "test_get_last_raft_log",
+    );
+
+    context.raft_log.reset().await.expect("should succeed");
+    let mut vec_1 = Vec::new();
+    for id in 1..300 {
+        vec_1.push(id);
+    }
+    test_utils::simulate_insert_command(&context.raft_log, vec_1, 1).await;
+
+    let mut vec_2 = Vec::new();
+    for id in 1..3 {
+        vec_2.push(id);
+    }
+    test_utils::simulate_insert_command(&context.raft_log, vec_2, 1).await;
+    if let Some(last) = context.raft_log.last_entry() {
+        assert_eq!(last.index, 301);
+    }
+}
+
+#[tokio::test]
+#[traced_test]
+async fn test_sled_last() {
+    let context = TestContext::new(
+        PersistenceStrategy::MemFirst,
+        FlushPolicy::Batch {
+            threshold: 1,
+            interval_ms: 1,
+        },
+        "test_sled_last",
+    );
+
+    test_utils::simulate_insert_command(&context.raft_log, (1..=300).collect(), 1).await;
+
+    let l = context.raft_log.last_entry().unwrap();
+    let last = l.index;
+    let len = context.raft_log.len();
+    debug!("last: {:?}, while len: {:?}", last, len);
+    assert_eq!(last, len as u64);
+}
+#[tokio::test]
+#[traced_test]
+async fn test_sled_last_max() {
+    let context = TestContext::new(
+        PersistenceStrategy::MemFirst,
+        FlushPolicy::Batch {
+            threshold: 1,
+            interval_ms: 1,
+        },
+        "test_sled_last_max",
+    );
+
+    let max = u64::MAX; //max of u64
+    test_utils::simulate_insert_command(&context.raft_log, ((max - 1)..max).collect(), 1).await;
+
+    let l = context.raft_log.last_entry().unwrap();
+    assert_eq!(l.index, 1);
+}
+
+///3 nodes, leader append 1000 logs, the other two logs can not get 1000
+/// entries
+/// to test insert_one_client_command and get_entries_range two functions
+#[tokio::test]
+#[traced_test]
+async fn test_insert_one_client_command() {
+    let context = TestContext::new(
+        PersistenceStrategy::MemFirst,
+        FlushPolicy::Batch {
+            threshold: 1,
+            interval_ms: 1,
+        },
+        "test_insert_one_client_command",
+    );
+
+    context.raft_log.reset().await.expect("reset successfully!");
+
+    let mut v = Vec::new();
+    for i in 1..2001 {
+        v.push(i);
+    }
+    test_utils::simulate_insert_command(&context.raft_log, v, 1).await;
+
+    let mut count = 900;
+    for entry in context.raft_log.get_entries_range(900..=2000).unwrap() {
+        assert_eq!(entry.index, count);
+        count += 1;
+    }
+}
+
+#[tokio::test]
+#[traced_test]
+async fn test_get_raft_log_entry_between() {
+    let context = TestContext::new(
+        PersistenceStrategy::MemFirst,
+        FlushPolicy::Batch {
+            threshold: 1,
+            interval_ms: 1,
+        },
+        "test_get_raft_log_entry_between",
+    );
+
+    context.raft_log.reset().await.expect("reset successfully!");
+
+    let mut v = Vec::new();
+    for i in 1..2001 {
+        v.push(i);
+    }
+    test_utils::simulate_insert_command(&context.raft_log, v, 1).await;
+
+    let log_len = context.raft_log.last_entry_id();
+    let result = context.raft_log.get_entries_range(900..=log_len).unwrap();
+    let mut count = 900;
+    for entry in &result {
+        assert_eq!(entry.index, count);
+        count += 1;
+    }
+    assert_eq!(result.len(), 1101);
+
+    let result = context.raft_log.get_entries_range(900..=log_len - 1).unwrap();
+    assert_eq!(result.len(), 1100);
+
+    //end index will not be returned as result
+    let result = context.raft_log.get_entries_range(0..=log_len).unwrap();
+    assert_eq!(result.len(), log_len as usize);
+
+    //index starts from 1
+    let result = context.raft_log.get_entries_range(0..=0).unwrap();
+    assert_eq!(result.len(), 0);
+
+    //index starts from 1
+    let result = context.raft_log.get_entries_range(0..=1).unwrap();
+    assert_eq!(result.len(), 1);
+}
+/// Test duplicated insert
+/// Leader might received duplicated commands from clients in several RPC
+/// request. But, leader should not treat them as duplicated entries. They are
+/// just sequence events.
+#[tokio::test]
+#[traced_test]
+async fn test_insert_one_client_command_dup_case() {
+    let context = TestContext::new(
+        PersistenceStrategy::MemFirst,
+        FlushPolicy::Batch {
+            threshold: 1,
+            interval_ms: 1,
+        },
+        "test_insert_one_client_command_dup_case",
+    );
+
+    context.raft_log.reset().await.expect("reset successfully!");
+
+    let mut v = Vec::new();
+    for i in 1..10 {
+        v.push(i);
+    }
+    test_utils::simulate_insert_command(&context.raft_log, v, 1).await;
+
+    let len = context.raft_log.last_entry_id();
+    let mut v = Vec::new();
+    for i in 1..10 {
+        v.push(i + len);
+    }
+    test_utils::simulate_insert_command(&context.raft_log, v, 2).await;
+
+    assert_eq!(context.raft_log.last_entry_id(), 18);
+    let last = context.raft_log.last_entry().unwrap();
+    assert_eq!(last.index, 18);
+}
+
+/// # Test client propose commands which contains insert and delete
+///
+/// ## Criterias:
+/// 1. all client proposal should be recorded in RaftLog without lose
+#[tokio::test]
+#[traced_test]
+async fn test_client_proposal_insert_delete() {
+    let context = TestContext::new(
+        PersistenceStrategy::MemFirst,
+        FlushPolicy::Batch {
+            threshold: 1,
+            interval_ms: 1,
+        },
+        "test_client_proposal_insert_delete",
+    );
+
+    context.raft_log.reset().await.expect("reset successfully!");
+
+    test_utils::simulate_insert_command(&context.raft_log, (1..=10).collect(), 1).await;
+    assert_eq!(context.raft_log.last_entry_id(), 10);
+
+    test_utils::simulate_delete_command(&context.raft_log, 1..=3, 1).await;
+    assert_eq!(context.raft_log.last_entry_id(), 13);
+    assert_eq!(context.raft_log.len(), 13);
+
+    test_utils::simulate_insert_command(&context.raft_log, (11..=20).collect(), 1).await;
+
+    assert_eq!(context.raft_log.last_entry_id(), 23);
+    assert_eq!(context.raft_log.len(), 23);
+}
+
+///Bug: setup logger with error: SetGlobalDefaultError("a global default trace
+/// dispatcher has already been set")
+/// #[traced_test]
+#[tokio::test]
+#[traced_test]
+async fn test_purge_logs_up_to() {
+    let context = TestContext::new(
+        PersistenceStrategy::MemFirst,
+        FlushPolicy::Batch {
+            threshold: 1,
+            interval_ms: 1,
+        },
+        "test_purge_logs_up_to",
+    );
+
+    context.raft_log.reset().await.expect("reset successfully!");
+
+    let mut entries = Vec::new();
+    for i in 1..10 {
+        entries.push(Entry {
+            index: i,
+            term: 1,
+            payload: None,
+        });
+    }
+    context.raft_log.insert_batch(entries).await.expect("should succeed");
+
+    //..
+    // assume we have generated snapshot until $last_applied,
+    // now we can clean the local logs
+    let last_applied = LogId { index: 3, term: 1 };
+    context.raft_log.purge_logs_up_to(last_applied).await.expect("should succeed");
+
+    assert_eq!(9, context.raft_log.last_entry_id());
+    assert_eq!(None, context.raft_log.entry(3).unwrap());
+    assert_eq!(None, context.raft_log.entry(2).unwrap());
+    assert_eq!(None, context.raft_log.entry(1).unwrap());
+}
+
+#[tokio::test]
+#[traced_test]
+async fn test_purge_logs_up_to_concurrent_purge() {
+    let context = TestContext::new(
+        PersistenceStrategy::MemFirst,
+        FlushPolicy::Batch {
+            threshold: 1,
+            interval_ms: 1,
+        },
+        "test_purge_logs_up_to_concurrent_purge",
+    );
+    context.raft_log.reset().await.expect("reset failed");
+
+    // Insert test logs
+    let entries: Vec<_> = (1..=10)
+        .map(|i| Entry {
+            index: i,
+            term: 1,
+            payload: None,
+        })
+        .collect();
+    context.raft_log.insert_batch(entries).await.unwrap();
+
+    // Concurrent purge calls
+    let handles: Vec<_> = vec![1, 2, 3, 4, 5, 6, 7]
+        .into_iter()
+        .map(|cutoff| {
+            let raft_log = context.raft_log.clone();
+            tokio::spawn(async move {
+                raft_log
+                    .purge_logs_up_to(LogId {
+                        index: cutoff,
+                        term: 1,
+                    })
+                    .await
+                    .unwrap();
+            })
+        })
+        .collect();
+
+    // Wait for all threads
+    join_all(handles).await;
+
+    // Verify final state
+    assert_eq!(10, context.raft_log.last_entry_id());
+
+    // The highest successful purge should win
+    assert!(context.raft_log.entry(7).unwrap().is_none());
+    assert!(context.raft_log.entry(8).unwrap().is_some());
+}
+
+#[tokio::test]
+#[traced_test]
+async fn test_get_first_raft_log_entry_id_after_delete_entries() {
+    let context = TestContext::new(
+        PersistenceStrategy::MemFirst,
+        FlushPolicy::Batch {
+            threshold: 1,
+            interval_ms: 1,
+        },
+        "test_get_first_raft_log_entry_id_after_delete_entries",
+    );
+
+    context.raft_log.reset().await.expect("reset successfully!");
+    let mut entries = Vec::new();
+    for i in 1..=10 {
+        entries.push(Entry {
+            index: i,
+            term: 1,
+            payload: None,
+        });
+    }
+    context.raft_log.insert_batch(entries).await.expect("should succeed");
+
+    let last_applied = LogId { index: 4, term: 1 };
+    context.raft_log.purge_logs_up_to(last_applied).await.expect("should succeed");
+    assert_eq!(10, context.raft_log.last_entry_id());
+    assert_eq!(None, context.raft_log.entry(3).unwrap());
+    assert_eq!(None, context.raft_log.entry(2).unwrap());
+    assert_eq!(None, context.raft_log.entry(1).unwrap());
+
+    assert_eq!(context.raft_log.first_entry_id(), 5);
+}
+
+/// Case 1: we have multi thread working concurrently
+///     each thread should get unique pre allocated index for pending apply
+/// entries     At last when we retrieve last entry of the locallog, we should
+/// see the last pre allocated index
+#[tokio::test]
+#[traced_test]
+async fn test_pre_allocate_raft_logs_next_index_case1() {
+    let context = TestContext::new(
+        PersistenceStrategy::DiskFirst,
+        FlushPolicy::Immediate,
+        "test_pre_allocate_raft_logs_next_index_case1",
+    );
+
+    context.raft_log.reset().await.expect("reset successfully!");
+    let start = context.raft_log.last_entry_id();
+    println!("start: {start}",);
+
+    let mut handles = Vec::new();
+
+    let i = 10;
+    let j = 10;
+    for _ in 1..=i {
+        let cloned_raft_log = context.raft_log.clone();
+        let handle = tokio::spawn(async move {
+            let mut entries: Vec<Entry> = Vec::new();
+            for i in 1..=j {
+                entries.push(Entry {
+                    index: cloned_raft_log.pre_allocate_raft_logs_next_index(),
+                    term: 1,
+                    payload: Some(EntryPayload::command(generate_insert_commands(vec![i]))),
+                });
+            }
+            cloned_raft_log.insert_batch(entries.clone()).await.expect("should succeed");
+        });
+        handles.push(handle);
+    }
+    let _results = join_all(handles).await;
+    let end = context.raft_log.last_entry_id();
+    println!("end:{end}",);
+
+    assert_eq!(start + i * j, end);
+}
+
+/// Case 2: we have mutil thread working concurrently
+///     there might be one thread failed to apply the local log entries
+///     which cases some log entry index might not really exists inside local
+/// logs     we still want to validate the last log entry id is the same one as
+/// we expected #[ignore = "architecture changes, this case will not exist"]
+#[tokio::test]
+#[traced_test]
+async fn test_pre_allocate_raft_logs_next_index_case2() {
+    let context = TestContext::new(
+        PersistenceStrategy::DiskFirst,
+        FlushPolicy::Immediate,
+        "test_pre_allocate_raft_logs_next_index_case2",
+    );
+
+    context.raft_log.reset().await.expect("reset successfully!");
+    let start = context.raft_log.last_entry_id();
+    println!("start: {start}",);
+
+    let mut handles = Vec::new();
+
+    let i = 10;
+    let k = 3; //make sure k<i
+    let j = 10;
+
+    // simulated failed apply thread
+    for _ in 1..=k {
+        let cloned_raft_log = context.raft_log.clone();
+        let handle = tokio::spawn(async move {
+            let mut entries: Vec<Entry> = Vec::new();
+            for i in 1..=j {
+                entries.push(Entry {
+                    index: cloned_raft_log.pre_allocate_raft_logs_next_index(),
+                    term: 1,
+                    payload: Some(EntryPayload::command(generate_insert_commands(vec![i]))),
+                });
+            }
+        });
+        handles.push(handle);
+    }
+
+    for _ in k + 1..=i {
+        let cloned_raft_log = context.raft_log.clone();
+        let handle = tokio::spawn(async move {
+            let mut entries: Vec<Entry> = Vec::new();
+            for i in 1..=j {
+                entries.push(Entry {
+                    index: cloned_raft_log.pre_allocate_raft_logs_next_index(),
+                    term: 1,
+                    payload: Some(EntryPayload::command(generate_insert_commands(vec![i]))),
+                });
+            }
+            cloned_raft_log.insert_batch(entries.clone()).await.expect("should succeed");
+        });
+        handles.push(handle);
+    }
+    let _results = join_all(handles).await;
+    let end = context.raft_log.last_entry_id();
+    println!("end:{end}",);
+
+    assert_eq!(start + i * j, end);
+}
+
+/// Case 1: stress testing with 100K entries,
+///     the entries was insert successfully and last log entry id is as expected
+#[ignore = "architecture changes, this case will not exist"]
+#[tokio::test]
+#[traced_test]
+async fn test_insert_batch_logs_case1() {
+    let context = TestContext::new(
+        PersistenceStrategy::MemFirst,
+        FlushPolicy::Immediate,
+        "test_insert_batch_logs_case1",
+    );
+
+    context.raft_log.reset().await.expect("reset successfully!");
+    let start = context.raft_log.last_entry_id();
+    println!("start: {start}",);
+
+    let mut handles = Vec::new();
+
+    let i = 1000;
+    let j = 100;
+
+    for _ in 1..=i {
+        let cloned_raft_log = context.raft_log.clone();
+        let handle = tokio::spawn(async move {
+            let mut entries: Vec<Entry> = Vec::new();
+            for i in 1..=j {
+                entries.push(Entry {
+                    index: cloned_raft_log.pre_allocate_raft_logs_next_index(),
+                    term: 1,
+                    payload: Some(EntryPayload::command(generate_insert_commands(vec![i]))),
+                });
+            }
+            cloned_raft_log.insert_batch(entries.clone()).await.expect("should succeed");
+        });
+        handles.push(handle);
+    }
+    let _results = join_all(handles).await;
+    let end = context.raft_log.last_entry_id();
+    println!("end:{end}",);
+
+    assert_eq!(start + i * j, end);
+}
+
+fn give_me_mock_storage() -> Arc<FileStorageEngine> {
+    // let mut mock_log_store = MockLogStore::new();
+    // mock_log_store.expect_last_index().returning(|| 0);
+    // mock_log_store.expect_persist_entries().returning(|_| Ok(()));
+    // mock_log_store.expect_entry().returning(|_| Ok(None));
+    // mock_log_store.expect_get_entries().returning(|_| Ok(vec![]));
+    // mock_log_store.expect_purge().returning(|_| Ok(()));
+    // mock_log_store.expect_truncate().returning(|_| Ok(()));
+    // mock_log_store.expect_flush().returning(|| Ok(()));
+    // mock_log_store.expect_flush_async().returning(|| Ok(()));
+    // mock_log_store.expect_reset().returning(|| Ok(()));
+
+    // let mut mock_meta_store = MockMetaStore::new();
+    // mock_meta_store.expect_save_hard_state().returning(|_| Ok(()));
+    // mock_meta_store.expect_load_hard_state().returning(|| Ok(None));
+    // mock_log_store.expect_flush().returning(|| Ok(()));
+    // mock_log_store.expect_flush_async().returning(|| Ok(()));
+
+    let temp_dir = tempdir().unwrap();
+    let path = temp_dir.path().to_path_buf();
+    Arc::new(FileStorageEngine::new(path).unwrap())
+}
+
+/// # Case 2: Test scenario for log replication conflict handling when combining:
+/// 1. `filter_out_conflicts_and_append` (follower's perspective)
+/// 2. `purge_logs_up_to` (snapshot compaction)
+/// 3. `insert_batch` (leader's log appending)
+///
+/// # Test Scenario Flow
+///
+/// 1. **Setup Phase**:
+///    - Old leader (T1) appends logs 1-10 (term 1)
+///    - Generates snapshot up to index 3 (compaction)
+///
+/// 2. **Leadership Change**:
+///    - Old leader restarts and becomes follower
+///    - New leader (T2) elected with logs 1-8 (term 1)
+///
+/// 3. **Conflict Handling**:
+///    - New leader appends logs 9-10 (term 2)
+///    - Old follower processes AppendEntries RPC
+///
+/// # Validation Points
+/// - Final log state must have last entry index=10, term=2
+/// - Log continuity: index 7 (term 1) and 8 (term 2) must coexist
+#[tokio::test]
+#[traced_test]
+async fn test_insert_batch_logs_case2() {
+    // 1. Initialize two nodes (old_leader and new_leader)
+    let (old_leader, receiver) =
+        BufferedRaftLog::<RaftTypeConfig<FileStorageEngine, MockStateMachine>>::new(
+            1,
+            PersistenceConfig {
+                strategy: PersistenceStrategy::DiskFirst,
+                flush_policy: FlushPolicy::Immediate,
+                max_buffered_entries: 1000,
+                ..Default::default()
+            },
+            give_me_mock_storage(),
+        );
+    let old_leader = old_leader.start(receiver);
+
+    let (new_leader, receiver) =
+        BufferedRaftLog::<RaftTypeConfig<FileStorageEngine, MockStateMachine>>::new(
+            2,
+            PersistenceConfig {
+                strategy: PersistenceStrategy::DiskFirst,
+                flush_policy: FlushPolicy::Immediate,
+                max_buffered_entries: 1000,
+                ..Default::default()
+            },
+            give_me_mock_storage(),
+        );
+    let new_leader = new_leader.start(receiver);
+
+    let mut entries: Vec<Entry> = Vec::new();
+    for i in 1..=7 {
+        entries.push(Entry {
+            index: old_leader.pre_allocate_raft_logs_next_index(),
+            term: 1,
+            payload: Some(EntryPayload::command(generate_insert_commands(vec![i]))),
+        });
+    }
+
+    // 2. Old leader initial logs (term 1)
+    old_leader.insert_batch(entries.clone()).await.expect("should succeed");
+    new_leader.insert_batch(entries.clone()).await.expect("should succeed");
+
+    // 3. Add uncommitted entry on old leader
+    old_leader
+        .insert_batch(vec![Entry {
+            index: old_leader.pre_allocate_raft_logs_next_index(),
+            term: 1,
+            payload: Some(EntryPayload::command(generate_insert_commands(vec![8]))),
+        }])
+        .await
+        .expect("should succeed");
+
+    // 4. Simulate snapshot compaction
+    let last_applied = LogId { index: 3, term: 1 };
+    old_leader.purge_logs_up_to(last_applied).await.expect("should succeed");
+
+    // 5. New leader appends higher term logs
+    let mut handles = Vec::new();
+    let mut new_leader_entries: Vec<Entry> = Vec::new();
+    for i in 8..=10 {
+        new_leader_entries.push(Entry {
+            index: new_leader.pre_allocate_raft_logs_next_index(),
+            term: 2,
+            payload: Some(EntryPayload::command(generate_insert_commands(vec![i]))),
+        });
+    }
+    let cloned_new_leader_entries = new_leader_entries.clone();
+    let handle = tokio::spawn(async move {
+        new_leader
+            .insert_batch(cloned_new_leader_entries.clone())
+            .await
+            .expect("should succeed");
+    });
+    handles.push(handle);
+    let _results = join_all(handles).await;
+
+    debug!("new_leader_entries: {:?}", new_leader_entries.clone());
+
+    // 6. Follower processes conflicting entries
+    let ex_leader_last_appled_id = old_leader
+        .filter_out_conflicts_and_append(8, 1, new_leader_entries.clone())
+        .await
+        .unwrap()
+        .unwrap();
+    assert_eq!(ex_leader_last_appled_id.index, 10);
+
+    // // 7. Validate final log state
+    // if let Some(ex_leader_last_entry) = old_leader.last() {
+    //     assert_eq!(ex_leader_last_entry.index, 10);
+    //     assert_eq!(ex_leader_last_entry.term, 2);
+    // }
+
+    // if let Some(entry) = old_leader.entry(7) {
+    //     assert_eq!(entry.term, 1);
+    // }
+    // if let Some(entry) = old_leader.entry(8) {
+    //     assert_eq!(entry.term, 2);
+    // }
+
+    // 7. Validate final log state
+    validate_log_continuity(
+        &old_leader,
+        &[
+            (7, 1),  // Original term 1 entry
+            (8, 2),  // Overwritten entry
+            (10, 2), // New highest entry
+        ],
+    )
+    .await;
+}
+
+/// Helper function: Validate log entries' term continuity
+async fn validate_log_continuity(
+    node: &Arc<BufferedRaftLog<RaftTypeConfig<FileStorageEngine, MockStateMachine>>>,
+    expected: &[(u64, u64)],
+) {
+    for (index, term) in expected {
+        let entry = node
+            .entry(*index)
+            .unwrap()
+            .unwrap_or_else(|| panic!("Missing entry at index {index}",));
+
+        assert_eq!(
+            entry.term, *term,
+            "Term mismatch at index {}: expected {}, got {}",
+            index, term, entry.term
+        );
+    }
+}
+
+#[tokio::test]
+#[traced_test]
+async fn test_apply_and_then_get_last() {
+    let context = TestContext::new(
+        PersistenceStrategy::MemFirst,
+        FlushPolicy::Batch {
+            threshold: 1,
+            interval_ms: 1,
+        },
+        "test_apply_and_then_get_last",
+    );
+
+    context.raft_log.reset().await.expect("reset successfully!");
+    test_utils::simulate_insert_command(&context.raft_log, vec![1, 2], 1).await;
+    assert_eq!(2, context.raft_log.last_entry_id());
+}
+
+#[tokio::test]
+#[traced_test]
+async fn test_pre_allocate_raft_logs_next_index() {
+    let context = TestContext::new(
+        PersistenceStrategy::MemFirst,
+        FlushPolicy::Immediate,
+        "test_pre_allocate_raft_logs_next_index",
+    );
+
+    assert_eq!(1, context.raft_log.pre_allocate_raft_logs_next_index());
+    assert_eq!(2, context.raft_log.pre_allocate_raft_logs_next_index());
+}
+
+#[tokio::test]
+#[traced_test]
+async fn test_calculate_majority_matched_index_case0() {
+    let c = TestContext::new(
+        PersistenceStrategy::MemFirst,
+        FlushPolicy::Batch {
+            threshold: 1,
+            interval_ms: 1,
+        },
+        "test_calculate_majority_matched_index_case0",
+    );
+    let raft_log = c.raft_log.clone();
+    raft_log.reset().await.expect("reset successfully!");
+
+    let current_term = 2;
+    let commit_index = 2;
+
+    test_utils::simulate_insert_command(&raft_log, vec![1], 1).await;
+    test_utils::simulate_insert_command(&raft_log, vec![2, 3], 2).await;
+
+    assert_eq!(
+        Some(3),
+        raft_log.calculate_majority_matched_index(current_term, commit_index, vec![2, 12])
+    );
+}
+
+/// If there exists an N such that N > commitIndex, a majority
+/// of matchIndex[i] ≥ N, and log[N].term == currentTerm: set commitIndex = N
+/// (§5.3, §5.4).
+#[tokio::test]
+#[traced_test]
+async fn test_calculate_majority_matched_index_case1() {
+    let c = TestContext::new(
+        PersistenceStrategy::MemFirst,
+        FlushPolicy::Batch {
+            threshold: 1,
+            interval_ms: 1,
+        },
+        "test_calculate_majority_matched_index_case1",
+    );
+    let raft_log = c.raft_log.clone();
+    let _ = c.raft_log.reset().await;
+    //case 1: majority matched index is 2, commit_index: 4, current_term is 3,
+    // while log(2) term is 2, return None
+    let ct = 3;
+    let ci = 4;
+
+    test_utils::simulate_insert_command(&raft_log, vec![1], 1).await;
+    test_utils::simulate_insert_command(&raft_log, vec![2], 2).await;
+    assert_eq!(
+        None,
+        raft_log.calculate_majority_matched_index(ct, ci, vec![1, 2])
+    );
+}
+
+#[tokio::test]
+#[traced_test]
+async fn test_calculate_majority_matched_index_case2() {
+    let c = TestContext::new(
+        PersistenceStrategy::MemFirst,
+        FlushPolicy::Batch {
+            threshold: 1,
+            interval_ms: 1,
+        },
+        "test_calculate_majority_matched_index_case2",
+    );
+    let raft_log = c.raft_log.clone();
+    let _ = c.raft_log.reset().await;
+
+    //case 2: majority matched index is 3, commit_index: 2, current_term is 3,
+    // while log(3) term is 3, return Some(3)
+    let ct = 3;
+    let ci = 2;
+
+    test_utils::simulate_insert_command(&raft_log, vec![1], 1).await;
+    test_utils::simulate_insert_command(&raft_log, vec![2], 2).await;
+    test_utils::simulate_insert_command(&raft_log, vec![3], 3).await;
+    assert_eq!(
+        Some(3),
+        raft_log.calculate_majority_matched_index(ct, ci, vec![4, 2])
+    );
+}
+
+#[tokio::test]
+#[traced_test]
+async fn test_calculate_majority_matched_index_case3() {
+    let c = TestContext::new(
+        PersistenceStrategy::MemFirst,
+        FlushPolicy::Batch {
+            threshold: 1,
+            interval_ms: 1,
+        },
+        "test_calculate_majority_matched_index_case3",
+    );
+    let raft_log = c.raft_log.clone();
+
+    //case 3: majority matched index is 3, commit_index: 2, current_term is 3,
+    // while log(3) term is 2, return None
+    let ct = 3;
+    let ci = 2;
+    test_utils::simulate_insert_command(&raft_log, vec![1], 1).await;
+    test_utils::simulate_insert_command(&raft_log, vec![2], 2).await;
+
+    assert_eq!(
+        None,
+        raft_log.calculate_majority_matched_index(ct, ci, vec![3, 2])
+    );
+}
+
+#[tokio::test]
+#[traced_test]
+async fn test_calculate_majority_matched_index_case4() {
+    let c = TestContext::new(
+        PersistenceStrategy::MemFirst,
+        FlushPolicy::Batch {
+            threshold: 1,
+            interval_ms: 1,
+        },
+        "test_calculate_majority_matched_index_case4",
+    );
+
+    let raft_log = c.raft_log.clone();
+
+    //case 3: majority matched index is 3, commit_index: 2, current_term is 3,
+    // while log(3) term is 2, return None
+    let ct = 3;
+    let ci = 2;
+
+    test_utils::simulate_insert_command(&raft_log, vec![1], 1).await;
+    test_utils::simulate_insert_command(&raft_log, vec![2], 2).await;
+
+    assert_eq!(
+        None,
+        raft_log.calculate_majority_matched_index(ct, ci, vec![2, 2])
+    );
+}
+
+/// # Case 5: stress testing
+///
+/// ## Setup
+/// 1. Simulate 100,000 local log entries
+/// 2. peer1's match: 90,000, peer2's match 98,000
+///
+/// ## Ceriteria:
+/// 1. compare calculate_majority_matched_index as calculate_majority_matched_index2's performance
+#[tokio::test]
+#[traced_test]
+async fn test_calculate_majority_matched_index_case5() {
+    let c = TestContext::new(
+        PersistenceStrategy::MemFirst,
+        FlushPolicy::Batch {
+            threshold: 1,
+            interval_ms: 1,
+        },
+        "test_calculate_majority_matched_index_case5",
+    );
+    let raft_log = c.raft_log.clone();
+
+    let term = 1;
+    let raft_log_length = 100000;
+    let commit = 90000;
+
+    let peer1_match = 97000;
+    let peer2_match = 98000;
+
+    let raft_log_entry_ids: Vec<u64> = (1..=raft_log_length).collect();
+    test_utils::simulate_insert_command(&raft_log, raft_log_entry_ids, 1).await;
+
+    let now = Instant::now();
+    assert_eq!(
+        Some(peer2_match),
+        raft_log.calculate_majority_matched_index(term, commit, vec![peer1_match, peer2_match])
+    );
+    println!(
+        "calculate_majority_matched_index takes: {} micros.",
+        now.elapsed().as_micros()
+    );
+}
+
+#[tokio::test]
+#[traced_test]
+async fn test_raft_log_insert() {
+    let c = TestContext::new(
+        PersistenceStrategy::MemFirst,
+        FlushPolicy::Batch {
+            threshold: 1,
+            interval_ms: 1,
+        },
+        "test_raft_log_insert",
+    );
+    let raft_log = c.raft_log.clone();
+
+    test_utils::simulate_insert_command(&raft_log, vec![1], 1).await;
+    assert_eq!(1, raft_log.last_entry_id());
+}
+
+/// #Case 1: local raft log is empty
+#[tokio::test]
+#[traced_test]
+async fn test_is_empty_case1() {
+    let c = TestContext::new(
+        PersistenceStrategy::MemFirst,
+        FlushPolicy::Immediate,
+        "test_is_empty_case1",
+    );
+    let raft_log = c.raft_log.clone();
+
+    assert!(raft_log.is_empty());
+}
+
+/// #Case 2: local raft log is not empty
+#[tokio::test]
+#[traced_test]
+async fn test_is_empty_case2() {
+    let c = TestContext::new(
+        PersistenceStrategy::MemFirst,
+        FlushPolicy::Batch {
+            threshold: 1,
+            interval_ms: 1,
+        },
+        "test_is_empty_case2",
+    );
+    let raft_log = c.raft_log.clone();
+    test_utils::simulate_insert_command(&raft_log, vec![1], 1).await;
+
+    assert!(!raft_log.is_empty());
+}
+
+/// # Case1: No last log in raft_log, should returns (0,0)
+#[tokio::test]
+#[traced_test]
+async fn test_get_last_entry_metadata_case1() {
+    let c = TestContext::new(
+        PersistenceStrategy::MemFirst,
+        FlushPolicy::Immediate,
+        "test_get_last_entry_metadata_case1",
+    );
+    let raft_log = c.raft_log.clone();
+
+    assert_eq!(
+        LogId { index: 0, term: 0 },
+        raft_log.last_log_id().unwrap_or(LogId { index: 0, term: 0 })
+    );
+}
+/// # Case2: There is last log in raft_log, should returns last log metadata
+#[tokio::test]
+#[traced_test]
+async fn test_get_last_entry_metadata_case2() {
+    let c = TestContext::new(
+        PersistenceStrategy::MemFirst,
+        FlushPolicy::Batch {
+            threshold: 1,
+            interval_ms: 1,
+        },
+        "test_get_last_entry_metadata_case2",
+    );
+    let raft_log = c.raft_log.clone();
+    test_utils::simulate_insert_command(&raft_log, vec![1], 11).await;
+
+    assert_eq!(
+        LogId { index: 1, term: 11 },
+        raft_log.last_log_id().unwrap_or(LogId { index: 0, term: 0 })
+    );
+}
+
+#[tokio::test]
+#[traced_test]
+async fn test_raft_log_drop() {
+    // Save the instance ID from the first storage
+
+    let temp_dir = tempdir().unwrap();
+    let path = temp_dir.path().to_path_buf();
+    let storage = FileStorageEngine::new(path.clone()).unwrap();
+
+    {
+        let (raft_log, receiver) =
+            BufferedRaftLog::<RaftTypeConfig<FileStorageEngine, MockStateMachine>>::new(
+                1,
+                PersistenceConfig {
+                    strategy: PersistenceStrategy::DiskFirst,
+                    flush_policy: FlushPolicy::Immediate,
+                    max_buffered_entries: 1000,
+                    ..Default::default()
+                },
+                Arc::new(storage),
+            );
+        let raft_log = raft_log.start(receiver);
+        test_utils::simulate_insert_command(&raft_log, vec![1], 1).await;
+        drop(raft_log);
+    }
+
+    // Reuse the same instance ID to access persisted entries
+    let storage = FileStorageEngine::new(path.clone()).unwrap();
+    assert!(!storage.log_store().get_entries(0..=1).unwrap().is_empty());
+}
+
+#[tokio::test]
+#[traced_test]
+async fn test_first_index_for_term() {
+    let context = TestContext::new(
+        PersistenceStrategy::MemFirst,
+        FlushPolicy::Batch {
+            threshold: 1,
+            interval_ms: 1,
+        },
+        "test_first_index_for_term",
+    );
+    context.raft_log.reset().await.expect("reset successfully!");
+
+    // Insert test logs with various terms
+    let entries = vec![
+        Entry {
+            index: 1,
+            term: 1,
+            payload: None,
+        },
+        Entry {
+            index: 2,
+            term: 1,
+            payload: None,
+        },
+        Entry {
+            index: 3,
+            term: 2,
+            payload: None,
+        },
+        Entry {
+            index: 4,
+            term: 2,
+            payload: None,
+        },
+        Entry {
+            index: 5,
+            term: 3,
+            payload: None,
+        },
+        Entry {
+            index: 6,
+            term: 3,
+            payload: None,
+        },
+        Entry {
+            index: 7,
+            term: 3,
+            payload: None,
+        },
+    ];
+    context.raft_log.insert_batch(entries).await.expect("insert should succeed");
+
+    // Test various cases
+    assert_eq!(context.raft_log.first_index_for_term(1), Some(1));
+    assert_eq!(context.raft_log.first_index_for_term(2), Some(3));
+    assert_eq!(context.raft_log.first_index_for_term(3), Some(5));
+    assert_eq!(context.raft_log.first_index_for_term(4), None); // Term not found
+
+    // Test with partial data
+    let entries = vec![
+        Entry {
+            index: 8,
+            term: 4,
+            payload: None,
+        },
+        Entry {
+            index: 9,
+            term: 5,
+            payload: None,
+        },
+    ];
+    context.raft_log.insert_batch(entries).await.expect("insert should succeed");
+    assert_eq!(context.raft_log.first_index_for_term(4), Some(8));
+    assert_eq!(context.raft_log.first_index_for_term(5), Some(9));
+
+    // Test with empty log
+    context.raft_log.reset().await.expect("reset should succeed");
+    assert_eq!(context.raft_log.first_index_for_term(1), None);
+}
+
+#[tokio::test]
+#[traced_test]
+async fn test_last_index_for_term() {
+    let context = TestContext::new(
+        PersistenceStrategy::MemFirst,
+        FlushPolicy::Batch {
+            threshold: 1,
+            interval_ms: 1,
+        },
+        "test_last_index_for_term",
+    );
+    context.raft_log.reset().await.expect("reset successfully!");
+
+    // Insert test logs with various terms
+    let entries = vec![
+        Entry {
+            index: 1,
+            term: 1,
+            payload: None,
+        },
+        Entry {
+            index: 2,
+            term: 1,
+            payload: None,
+        },
+        Entry {
+            index: 3,
+            term: 2,
+            payload: None,
+        },
+        Entry {
+            index: 4,
+            term: 2,
+            payload: None,
+        },
+        Entry {
+            index: 5,
+            term: 3,
+            payload: None,
+        },
+        Entry {
+            index: 6,
+            term: 3,
+            payload: None,
+        },
+        Entry {
+            index: 7,
+            term: 3,
+            payload: None,
+        },
+    ];
+    context.raft_log.insert_batch(entries).await.expect("insert should succeed");
+
+    // Test various cases
+    assert_eq!(context.raft_log.last_index_for_term(1), Some(2));
+    assert_eq!(context.raft_log.last_index_for_term(2), Some(4));
+    assert_eq!(context.raft_log.last_index_for_term(3), Some(7));
+    assert_eq!(context.raft_log.last_index_for_term(4), None); // Term not found
+
+    // Test with gaps in terms
+    let entries = vec![
+        Entry {
+            index: 8,
+            term: 5,
+            payload: None,
+        },
+        Entry {
+            index: 9,
+            term: 5,
+            payload: None,
+        },
+    ];
+    context.raft_log.insert_batch(entries).await.expect("insert should succeed");
+    assert_eq!(context.raft_log.last_index_for_term(5), Some(9));
+
+    // Test with empty log
+    context.raft_log.reset().await.expect("reset should succeed");
+    assert_eq!(context.raft_log.last_index_for_term(1), None);
+}
+
+#[tokio::test]
+#[traced_test]
+async fn test_term_index_functions_with_purged_logs() {
+    let context = TestContext::new(
+        PersistenceStrategy::MemFirst,
+        FlushPolicy::Batch {
+            threshold: 1,
+            interval_ms: 1,
+        },
+        "test_term_index_functions_with_purged_logs",
+    );
+    context.raft_log.reset().await.expect("reset successfully!");
+
+    // Insert initial logs
+    let entries: Vec<_> = (1..=10)
+        .map(|i| Entry {
+            index: i,
+            term: if i <= 3 { 1 } else { 2 },
+            payload: None,
+        })
+        .collect();
+    context.raft_log.insert_batch(entries).await.expect("insert should succeed");
+
+    // Purge first 5 logs
+    context
+        .raft_log
+        .purge_logs_up_to(LogId { index: 5, term: 2 })
+        .await
+        .expect("purge should succeed");
+
+    // Verify after purge
+    assert_eq!(context.raft_log.first_index_for_term(1), None); // Term 1 purged
+    assert_eq!(context.raft_log.last_index_for_term(1), None); // Term 1 purged
+    assert_eq!(context.raft_log.first_index_for_term(2), Some(6));
+    assert_eq!(context.raft_log.last_index_for_term(2), Some(10));
+}
+
+#[tokio::test]
+#[traced_test]
+async fn test_term_index_functions_with_concurrent_writes() {
+    let (raft_log, log_command_receiver) =
+        BufferedRaftLog::<RaftTypeConfig<FileStorageEngine, MockStateMachine>>::new(
+            1,
+            PersistenceConfig {
+                strategy: PersistenceStrategy::MemFirst,
+                flush_policy: FlushPolicy::Immediate,
+                max_buffered_entries: 1000,
+                ..Default::default()
+            },
+            give_me_mock_storage(),
+        );
+    let raft_log = raft_log.start(log_command_receiver);
+    // raft_log.reset().await.expect("reset successfully!");
+
+    // Add a small delay to ensure command processor is ready
+    tokio::time::sleep(tokio::time::Duration::from_millis(10)).await;
+
+    let mut handles = Vec::new();
+
+    for i in 0..10 {
+        let cloned_raft_log = raft_log.clone();
+        let handle = tokio::spawn(async move {
+            let term = i + 1;
+            for j in 1..=100 {
+                let index = (i * 100) + j;
+                let entry = Entry {
+                    index,
+                    term,
+                    payload: None,
+                };
+                cloned_raft_log.insert_batch(vec![entry]).await.expect("insert should succeed");
+            }
+        });
+        handles.push(handle);
+    }
+
+    for handle in handles {
+        handle.await.expect("task panicked");
+        println!("Task completed");
+    }
+
+    // Small delay to ensure all persist commands are processed
+    tokio::time::sleep(tokio::time::Duration::from_millis(50)).await;
+
+    // Verify term indices
+    for term in 1..=10 {
+        assert_eq!(
+            raft_log.first_index_for_term(term),
+            Some((term - 1) * 100 + 1)
+        );
+        assert_eq!(raft_log.last_index_for_term(term), Some(term * 100));
+    }
+}
+
+#[tokio::test]
+#[traced_test]
+async fn test_term_index_performance_large_dataset() {
+    let context = TestContext::new(
+        PersistenceStrategy::MemFirst,
+        FlushPolicy::Batch {
+            threshold: 1,
+            interval_ms: 1,
+        },
+        "test_term_index_performance_large_dataset",
+    );
+    context.raft_log.reset().await.expect("reset successfully!");
+
+    // Insert 100,000 logs with terms cycling every 100 logs
+    let mut entries = Vec::new();
+    for i in 1..=100_000 {
+        let term = i / 100 + 1;
+        entries.push(Entry {
+            index: i,
+            term,
+            payload: None,
+        });
+    }
+    context.raft_log.insert_batch(entries).await.expect("insert should succeed");
+
+    // Measure performance for first_index_for_term
+    let start = std::time::Instant::now();
+    assert_eq!(context.raft_log.first_index_for_term(1), Some(1));
+    assert_eq!(context.raft_log.first_index_for_term(500), Some(49900));
+    assert_eq!(context.raft_log.first_index_for_term(1000), Some(99900));
+    println!("first_index_for_term took: {:?}", start.elapsed());
+
+    // Measure performance for last_index_for_term
+    let start = std::time::Instant::now();
+    assert_eq!(context.raft_log.last_index_for_term(1), Some(99));
+    assert_eq!(context.raft_log.last_index_for_term(500), Some(49999));
+    assert_eq!(context.raft_log.last_index_for_term(1000), Some(99999));
+    println!("last_index_for_term took: {:?}", start.elapsed());
+}
+#[cfg(test)]
+mod id_allocation_tests {
+    use std::collections::HashSet;
+    use std::ops::RangeInclusive;
+    use std::sync::Arc;
+    use std::sync::atomic::Ordering;
+
+    use super::*;
+    use d_engine_server::FileStorageEngine;
+
+    // In-memory test setup
+    fn setup_memory() -> Arc<BufferedRaftLog<RaftTypeConfig<FileStorageEngine, MockStateMachine>>> {
+        let (raft_log, _receiver) =
+            BufferedRaftLog::<RaftTypeConfig<FileStorageEngine, MockStateMachine>>::new(
+                1,
+                PersistenceConfig {
+                    strategy: PersistenceStrategy::MemFirst,
+                    flush_policy: FlushPolicy::Immediate,
+                    max_buffered_entries: 1000,
+                    ..Default::default()
+                },
+                give_me_mock_storage(),
+            );
+
+        Arc::new(raft_log)
+    }
+
+    // Helper to check empty ranges
+    fn is_empty_range(range: &RangeInclusive<u64>) -> bool {
+        range.start() == &u64::MAX && range.end() == &u64::MAX
+    }
+
+    #[tokio::test]
+    async fn test_pre_allocate_next_index_sequential() {
+        let raft_log = setup_memory();
+
+        assert_eq!(raft_log.pre_allocate_raft_logs_next_index(), 1);
+        assert_eq!(raft_log.pre_allocate_raft_logs_next_index(), 2);
+        assert_eq!(raft_log.pre_allocate_raft_logs_next_index(), 3);
+
+        assert_eq!(raft_log.next_id.load(Ordering::SeqCst), 4);
+    }
+
+    #[tokio::test]
+    async fn test_pre_allocate_id_range_exact_batch() {
+        let raft_log = setup_memory();
+
+        let range = raft_log.pre_allocate_id_range(100);
+        assert_eq!(*range.start(), 1);
+        assert_eq!(*range.end(), 100);
+
+        assert_eq!(raft_log.pre_allocate_raft_logs_next_index(), 101);
+    }
+
+    #[tokio::test]
+    async fn test_pre_allocate_id_range_zero_count() {
+        let raft_log = setup_memory();
+        let initial_id = raft_log.next_id.load(Ordering::SeqCst);
+
+        let range = raft_log.pre_allocate_id_range(0);
+        assert!(is_empty_range(&range));
+        assert_eq!(raft_log.next_id.load(Ordering::SeqCst), initial_id);
+    }
+
+    #[tokio::test]
+    async fn test_pre_allocate_id_range_after_zero() {
+        let raft_log = setup_memory();
+
+        // Allocate 0 (should be empty)
+        let empty_range = raft_log.pre_allocate_id_range(0);
+        assert!(is_empty_range(&empty_range));
+
+        // Valid allocation should work after empty
+        let range = raft_log.pre_allocate_id_range(5);
+        assert_eq!(*range.start(), 1);
+        assert_eq!(*range.end(), 5);
+    }
+
+    #[tokio::test]
+    async fn test_pre_allocate_id_range_concurrent() {
+        let raft_log = setup_memory();
+        let raft_log_clone = Arc::clone(&raft_log);
+
+        let handle = std::thread::spawn(move || raft_log_clone.pre_allocate_id_range(50));
+
+        let main_range = raft_log.pre_allocate_id_range(30);
+        let thread_range = handle.join().unwrap();
+
+        // Verify range size (no null check required)
+        let main_count = main_range.end() - main_range.start() + 1;
+        let thread_count = thread_range.end() - thread_range.start() + 1;
+        assert_eq!(main_count, 30);
+        assert_eq!(thread_count, 50);
+
+        // Get all range endpoints
+        let points = [
+            *main_range.start(),
+            *main_range.end(),
+            *thread_range.start(),
+            *thread_range.end(),
+        ];
+
+        let min_id = *points.iter().min().unwrap();
+        let max_id = *points.iter().max().unwrap();
+
+        // Verify continuity: total number of IDs = (max_id - min_id + 1)
+        assert_eq!(main_count + thread_count, max_id - min_id + 1);
+
+        // Verify final status
+        assert_eq!(raft_log.next_id.load(Ordering::SeqCst), max_id + 1);
+    }
+
+    // Define result enumeration inside the test module
+    #[derive(Debug)]
+    enum AllocationResult {
+        Single(u64),
+        Range(RangeInclusive<u64>),
+    }
+
+    #[tokio::test]
+    async fn test_concurrent_mixed_allocations() {
+        let raft_log = setup_memory();
+        let mut handles = vec![];
+
+        // Start multiple threads for mixed allocation
+        for _ in 0..10 {
+            let log_clone = Arc::clone(&raft_log);
+            handles.push(std::thread::spawn(move || {
+                // Single ID allocation
+                let id = log_clone.pre_allocate_raft_logs_next_index();
+                AllocationResult::Single(id)
+            }));
+        }
+
+        for _ in 0..5 {
+            let log_clone = Arc::clone(&raft_log);
+            handles.push(std::thread::spawn(move || {
+                // range allocation
+                let range = log_clone.pre_allocate_id_range(10);
+                AllocationResult::Range(range)
+            }));
+        }
+
+        // collect results
+        let mut results = vec![];
+        for handle in handles {
+            results.push(handle.join().unwrap());
+        }
+
+        // Verify there are no duplicate IDs
+        let mut all_ids = HashSet::new();
+        for result in &results {
+            match result {
+                AllocationResult::Single(id) => {
+                    assert!(!all_ids.contains(id), "Duplicate ID: {id}",);
+                    all_ids.insert(*id);
+                }
+                AllocationResult::Range(range) => {
+                    if !range.is_empty() {
+                        for id in *range.start()..=*range.end() {
+                            assert!(!all_ids.contains(&id), "Duplicate ID: {id}",);
+                            all_ids.insert(id);
+                        }
+                    }
+                }
+            }
+        }
+
+        // Get the minimum and maximum IDs
+        let min_id = *all_ids.iter().min().unwrap_or(&0);
+        let max_id = *all_ids.iter().max().unwrap_or(&0);
+
+        // Verify continuity and total count
+        if !all_ids.is_empty() {
+            assert_eq!(
+                all_ids.len() as u64,
+                max_id - min_id + 1,
+                "IDs are not contiguous: min={}, max={}, count={}, expected_count={}",
+                min_id,
+                max_id,
+                all_ids.len(),
+                max_id - min_id + 1
+            );
+
+            // Verify final status
+            assert_eq!(
+                raft_log.next_id.load(Ordering::SeqCst),
+                max_id + 1,
+                "Next ID mismatch: expected {}, actual {}",
+                max_id + 1,
+                raft_log.next_id.load(Ordering::SeqCst)
+            );
+        }
+    }
+
+    #[tokio::test]
+    async fn test_pre_allocate_id_range_multiple_batches() {
+        let raft_log = setup_memory();
+
+        // Valid batches
+        let range1 = raft_log.pre_allocate_id_range(150);
+        let range2 = raft_log.pre_allocate_id_range(50);
+
+        // Empty batch
+        let empty_range = raft_log.pre_allocate_id_range(0);
+
+        // Another valid batch
+        let range3 = raft_log.pre_allocate_id_range(100);
+
+        assert_eq!(*range1.start(), 1);
+        assert_eq!(*range1.end(), 150);
+
+        assert_eq!(*range2.start(), 151);
+        assert_eq!(*range2.end(), 200);
+
+        assert!(is_empty_range(&empty_range));
+
+        assert_eq!(*range3.start(), 201);
+        assert_eq!(*range3.end(), 300);
+    }
+
+    #[tokio::test]
+    async fn test_mixed_allocation_strategies() {
+        let raft_log = setup_memory();
+
+        // Single allocation
+        assert_eq!(raft_log.pre_allocate_raft_logs_next_index(), 1);
+
+        // Empty range
+        let empty = raft_log.pre_allocate_id_range(0);
+        assert!(is_empty_range(&empty));
+
+        // Range allocation
+        let range = raft_log.pre_allocate_id_range(5);
+        assert_eq!(*range.start(), 2);
+        assert_eq!(*range.end(), 6);
+
+        // More single allocations
+        assert_eq!(raft_log.pre_allocate_raft_logs_next_index(), 7);
+        assert_eq!(raft_log.pre_allocate_raft_logs_next_index(), 8);
+
+        // Large range allocation
+        let range = raft_log.pre_allocate_id_range(250);
+        assert_eq!(*range.start(), 9);
+        assert_eq!(*range.end(), 258);
+
+        // Final check
+        assert_eq!(raft_log.pre_allocate_raft_logs_next_index(), 259);
+    }
+
+    #[tokio::test]
+    async fn test_edge_cases() {
+        let raft_log = setup_memory();
+
+        // Single ID
+        let single = raft_log.pre_allocate_id_range(1);
+        assert_eq!(*single.start(), 1);
+        assert_eq!(*single.end(), 1);
+
+        // Maximum u64 (theoretical, not recommended in practice)
+        raft_log.next_id.store(u64::MAX - 5, Ordering::SeqCst);
+        let range = raft_log.pre_allocate_id_range(5);
+        assert_eq!(*range.start(), u64::MAX - 5);
+        assert_eq!(*range.end(), u64::MAX - 1);
+    }
+}
+
+// Strategy-specific test module
+mod disk_first_tests {
+
+    use super::*;
+
+    #[tokio::test]
+    async fn test_basic_write_and_read() {
+        let ctx = TestContext::new(
+            PersistenceStrategy::DiskFirst,
+            FlushPolicy::Immediate,
+            "test_basic_write_and_read",
+        );
+        ctx.append_entries(1, 5, 1).await;
+
+        // Verify entries are immediately durable
+        assert_eq!(ctx.raft_log.durable_index.load(Ordering::Acquire), 5);
+        assert_eq!(ctx.raft_log.entry(3).unwrap().unwrap().index, 3);
+    }
+
+    #[tokio::test]
+    async fn test_crash_recovery() {
+        // Create and populate storage
+        let original_ctx = TestContext::new(
+            PersistenceStrategy::DiskFirst,
+            FlushPolicy::Immediate,
+            "test_crash_recovery",
+        );
+
+        // Append an entry
+        original_ctx
+            .raft_log
+            .append_entries(vec![Entry {
+                index: 1,
+                term: 1,
+                payload: Some(EntryPayload::command(Bytes::from(b"data".to_vec()))),
+            }])
+            .await
+            .unwrap();
+
+        // Ensure the entry is persisted for DiskFirst strategy
+        original_ctx.raft_log.flush().await.unwrap();
+
+        // Recover from the same storage (simulating restart)
+        let recovered_ctx = original_ctx.recover_from_crash();
+
+        // Simulate crash by dropping the original context
+        drop(original_ctx);
+
+        sleep(Duration::from_millis(50)).await; // Allow recovery
+
+        // Verify recovery - for DiskFirst, entries should be immediately durable
+        assert_eq!(
+            recovered_ctx.raft_log.durable_index.load(Ordering::Acquire),
+            1
+        );
+
+        // The entry should be available
+        let entry = recovered_ctx.raft_log.entry(1).unwrap();
+        assert!(entry.is_some());
+        assert_eq!(entry.unwrap().index, 1);
+    }
+
+    // Add this test to verify the fix works correctly
+    #[tokio::test]
+    async fn test_crash_recovery_with_multiple_entries() {
+        // Create and populate storage
+        let original_ctx = TestContext::new(
+            PersistenceStrategy::DiskFirst,
+            FlushPolicy::Immediate,
+            "test_crash_recovery_with_multiple_entries",
+        );
+
+        // Append multiple entries
+        for i in 1..=5 {
+            original_ctx
+                .raft_log
+                .append_entries(vec![Entry {
+                    index: i,
+                    term: 1,
+                    payload: Some(EntryPayload::command(Bytes::from(
+                        format!("data{i}",).into_bytes(),
+                    ))),
+                }])
+                .await
+                .unwrap();
+        }
+
+        // Ensure all entries are persisted for DiskFirst strategy
+        original_ctx.raft_log.flush().await.unwrap();
+
+        // Verify all entries are in memory and durable
+        assert_eq!(
+            original_ctx.raft_log.durable_index.load(Ordering::Acquire),
+            5
+        );
+        assert_eq!(original_ctx.raft_log.entries.len(), 5);
+
+        // Recover from the same storage (simulating restart)
+        let recovered_ctx = original_ctx.recover_from_crash();
+
+        // Simulate crash by dropping the original context
+        drop(original_ctx);
+
+        sleep(Duration::from_millis(50)).await; // Allow recovery
+
+        // Verify recovery - all entries should be recovered
+        assert_eq!(
+            recovered_ctx.raft_log.durable_index.load(Ordering::Acquire),
+            5
+        );
+        assert_eq!(recovered_ctx.raft_log.entries.len(), 5);
+
+        // All entries should be available
+        for i in 1..=5 {
+            let entry = recovered_ctx.raft_log.entry(i).unwrap();
+            assert!(entry.is_some());
+            assert_eq!(entry.unwrap().index, i);
+        }
+    }
+
+    // Test for MemFirst strategy crash recovery (should lose unflushed data)
+    #[tokio::test]
+    async fn test_crash_recovery_mem_first() {
+        // Create and populate storage with MemFirst strategy
+        let original_ctx = TestContext::new(
+            PersistenceStrategy::MemFirst,
+            FlushPolicy::Batch {
+                threshold: 10,
+                interval_ms: 1000,
+            },
+            "test_crash_recovery_mem_first",
+        );
+
+        // Append entries but don't flush (simulate data in memory only)
+        for i in 1..=3 {
+            original_ctx
+                .raft_log
+                .append_entries(vec![Entry {
+                    index: i,
+                    term: 1,
+                    payload: Some(EntryPayload::command(Bytes::from(
+                        format!("data{i}",).into_bytes(),
+                    ))),
+                }])
+                .await
+                .unwrap();
+        }
+
+        // Verify entries are in memory but not durable
+        assert_eq!(original_ctx.raft_log.entries.len(), 3);
+        assert_eq!(
+            original_ctx.raft_log.durable_index.load(Ordering::Acquire),
+            0
+        );
+
+        // Recover from the same storage (simulating restart)
+        let recovered_ctx = original_ctx.recover_from_crash();
+
+        // Simulate crash by dropping the original context without flushing
+        drop(original_ctx);
+
+        sleep(Duration::from_millis(50)).await; // Allow recovery
+
+        // Verify recovery - for MemFirst without flush, data should be lost
+        assert_eq!(
+            recovered_ctx.raft_log.durable_index.load(Ordering::Acquire),
+            0
+        );
+        assert_eq!(recovered_ctx.raft_log.entries.len(), 0);
+
+        // No entries should be available
+        for i in 1..=3 {
+            let entry = recovered_ctx.raft_log.entry(i).unwrap();
+            assert!(entry.is_none());
+        }
+    }
+
+    #[tokio::test]
+    async fn test_high_concurrency() {
+        let ctx = TestContext::new(
+            PersistenceStrategy::DiskFirst,
+            FlushPolicy::Immediate,
+            "test_high_concurrency",
+        );
+        let mut handles = vec![];
+
+        for i in 0..10 {
+            let log = ctx.raft_log.clone();
+            handles.push(tokio::spawn(async move {
+                for j in 1..=100 {
+                    let index = i * 100 + j;
+                    log.append_entries(vec![Entry {
+                        index,
+                        term: 1,
+                        payload: None,
+                    }])
+                    .await
+                    .unwrap();
+                }
+            }));
+        }
+
+        for handle in handles {
+            handle.await.unwrap();
+        }
+
+        // Verify all entries persisted
+        assert_eq!(ctx.raft_log.durable_index.load(Ordering::Acquire), 1000);
+        assert_eq!(ctx.raft_log.entries.len(), 1000);
+    }
+}
+
+mod mem_first_tests {
+
+    use super::*;
+    use d_engine_core::LogStore;
+    use d_engine_core::StorageEngine;
+
+    #[tokio::test]
+    async fn test_basic_write_before_persist() {
+        let ctx = TestContext::new(
+            PersistenceStrategy::MemFirst,
+            FlushPolicy::Batch {
+                threshold: 1,
+                interval_ms: 1,
+            },
+            "test_basic_write_before_persist",
+        );
+        ctx.append_entries(1, 5, 1).await;
+
+        // Verify in memory but not yet durable
+        assert_eq!(ctx.raft_log.entries.len(), 5);
+        assert_eq!(ctx.raft_log.durable_index.load(Ordering::Acquire), 0);
+    }
+
+    #[tokio::test]
+    async fn test_async_persistence() {
+        let ctx = TestContext::new(
+            PersistenceStrategy::MemFirst,
+            FlushPolicy::Batch {
+                threshold: 1,
+                interval_ms: 1,
+            },
+            "test_async_persistence",
+        );
+        ctx.append_entries(1, 100, 1).await;
+
+        // Trigger flush
+        ctx.raft_log.flush().await.unwrap();
+
+        // Verify persistence
+        assert_eq!(ctx.raft_log.durable_index.load(Ordering::Acquire), 100);
+        assert_eq!(ctx.storage.as_ref().log_store().last_index(), 100);
+    }
+
+    #[tokio::test]
+    async fn test_power_loss_data_loss() {
+        let ctx = TestContext::new(
+            PersistenceStrategy::MemFirst,
+            FlushPolicy::Batch {
+                threshold: 1,
+                interval_ms: 1,
+            },
+            "test_power_loss_data_loss",
+        );
+        ctx.append_entries(1, 100, 1).await;
+
+        // Simulate power loss before flush
+        // storage.reset() simulates data loss after crash
+
+        // In real scenario, durable_index would be 0 after restart
+        assert_eq!(ctx.raft_log.durable_index.load(Ordering::Acquire), 0);
+    }
+
+    #[tokio::test]
+    async fn test_high_concurrency_memory_only() {
+        let ctx = TestContext::new(
+            PersistenceStrategy::MemFirst,
+            FlushPolicy::Batch {
+                threshold: 1,
+                interval_ms: 1,
+            },
+            "test_high_concurrency_memory_only",
+        );
+        let mut handles = vec![];
+
+        for i in 0..10 {
+            let log = ctx.raft_log.clone();
+            handles.push(tokio::spawn(async move {
+                for j in 1..=100 {
+                    let index = i * 100 + j;
+                    log.append_entries(vec![Entry {
+                        index,
+                        term: 1,
+                        payload: None,
+                    }])
+                    .await
+                    .unwrap();
+                }
+            }));
+        }
+
+        for handle in handles {
+            handle.await.unwrap();
+        }
+
+        // Verify all entries in memory
+        assert_eq!(ctx.raft_log.entries.len(), 1000);
+        assert_eq!(ctx.raft_log.last_entry_id(), 1000);
+    }
+}
+
+mod batched_tests {
+    use super::*;
+
+    #[tokio::test]
+    async fn test_batch_flush_trigger() {
+        let ctx = TestContext::new(
+            PersistenceStrategy::MemFirst,
+            FlushPolicy::Batch {
+                threshold: 10,
+                interval_ms: 100,
+            },
+            "test_batch_flush_trigger",
+        );
+
+        // Add 9 entries - should not trigger flush
+        ctx.append_entries(1, 9, 1).await;
+        assert_eq!(ctx.raft_log.durable_index.load(Ordering::Acquire), 0);
+
+        // Add 1 more to reach batch size
+        ctx.append_entries(10, 1, 1).await;
+        sleep(Duration::from_millis(50)).await; // Allow time for async processing
+
+        // Should have flushed first 10
+        assert_eq!(ctx.raft_log.durable_index.load(Ordering::Acquire), 10);
+    }
+
+    #[tokio::test]
+    async fn test_timed_flush_trigger() {
+        let ctx = TestContext::new(
+            PersistenceStrategy::MemFirst,
+            FlushPolicy::Batch {
+                threshold: 100,
+                interval_ms: 50,
+            },
+            "test_timed_flush_trigger",
+        );
+        ctx.append_entries(1, 50, 1).await;
+
+        // Wait for timer to trigger
+        sleep(Duration::from_millis(75)).await;
+
+        // Should have flushed via timer
+        assert!(ctx.raft_log.durable_index.load(Ordering::Acquire) > 0);
+    }
+
+    #[tokio::test]
+    async fn test_partial_flush_after_crash() {
+        let batch_size = 50;
+
+        // Create and partially populate storage
+        {
+            // let (db, _) = reset_dbs(db_path.to_str().unwrap());
+
+            // let log_tree = db.open_tree("raft_log_tree").unwrap();
+            // let meta_tree = db.open_tree("raft_meta_tree").unwrap();
+            // let storage = Arc::new(FileStorageEngine::new());
+            let (raft_log, receiver) =
+                BufferedRaftLog::<RaftTypeConfig<FileStorageEngine, MockStateMachine>>::new(
+                    1,
+                    PersistenceConfig {
+                        strategy: PersistenceStrategy::MemFirst,
+                        flush_policy: FlushPolicy::Batch {
+                            threshold: batch_size,
+                            interval_ms: 100,
+                        },
+                        max_buffered_entries: 1000,
+                        ..Default::default()
+                    },
+                    give_me_mock_storage(),
+                );
+            let raft_log = raft_log.start(receiver);
+
+            // Add 75 entries (1.5 batches)
+            for i in 1..=75 {
+                raft_log
+                    .append_entries(vec![Entry {
+                        index: i,
+                        term: 1,
+                        payload: None,
+                    }])
+                    .await
+                    .unwrap();
+            }
+
+            // Simulate crash without proper shutdown
+        }
+
+        // Recover from disk
+        // let (db, _) = reuse_dbs(db_path.to_str().unwrap());
+
+        // let log_tree = db.open_tree("raft_log_tree").unwrap();
+        // let meta_tree = db.open_tree("raft_meta_tree").unwrap();
+        // let storage = Arc::new(FileStorageEngine::new());
+        let (raft_log, receiver) =
+            BufferedRaftLog::<RaftTypeConfig<FileStorageEngine, MockStateMachine>>::new(
+                1,
+                PersistenceConfig {
+                    strategy: PersistenceStrategy::MemFirst,
+                    flush_policy: FlushPolicy::Batch {
+                        threshold: batch_size,
+                        interval_ms: 100,
+                    },
+                    max_buffered_entries: 1000,
+                    ..Default::default()
+                },
+                give_me_mock_storage(),
+            );
+        let raft_log = raft_log.start(receiver);
+        sleep(Duration::from_millis(50)).await; // Allow recovery
+
+        // Only first batch should be durable
+        assert_eq!(raft_log.durable_index.load(Ordering::Acquire), 0); //because batch threshold is 100
+        assert!(raft_log.entry(60).unwrap().is_none()); // Not persisted
+    }
+}
+
+// Generic tests for all strategies
+mod common_tests {
+    use super::*;
+
+    #[tokio::test]
+    async fn test_log_compaction() {
+        let ctx = TestContext::new(
+            PersistenceStrategy::DiskFirst,
+            FlushPolicy::Immediate,
+            "test_log_compaction",
+        );
+        ctx.append_entries(1, 100, 1).await;
+
+        // Compact first 50 entries
+        ctx.raft_log.purge_logs_up_to(LogId { index: 50, term: 1 }).await.unwrap();
+
+        // Verify compaction
+        assert!(ctx.raft_log.entry(25).unwrap().is_none());
+        assert_eq!(ctx.raft_log.first_entry_id(), 51);
+        assert_eq!(ctx.raft_log.durable_index.load(Ordering::Acquire), 100);
+    }
+
+    #[tokio::test]
+    async fn test_term_index_calculation() {
+        let ctx = TestContext::new(
+            PersistenceStrategy::MemFirst,
+            FlushPolicy::Batch {
+                threshold: 1,
+                interval_ms: 1,
+            },
+            "test_term_index_calculation",
+        );
+
+        // Add entries with different terms
+        ctx.append_entries(1, 50, 1).await;
+        ctx.append_entries(51, 50, 2).await;
+        ctx.append_entries(101, 50, 3).await;
+
+        // Verify term indices
+        assert_eq!(ctx.raft_log.first_index_for_term(2), Some(51));
+        assert_eq!(ctx.raft_log.last_index_for_term(2), Some(100));
+        assert_eq!(ctx.raft_log.last_index_for_term(3), Some(150));
+    }
+
+    #[tokio::test]
+    async fn test_drop_behavior() {
+        let ctx = TestContext::new(
+            PersistenceStrategy::MemFirst,
+            FlushPolicy::Batch {
+                threshold: 10,
+                interval_ms: 100,
+            },
+            "test_drop_behavior",
+        );
+        ctx.append_entries(1, 5, 1).await;
+
+        // Explicitly drop context
+        drop(ctx);
+
+        // Test passes if no deadlock occurs during drop
+    }
+
+    #[tokio::test]
+    async fn test_reset_operation() {
+        let ctx = TestContext::new(
+            PersistenceStrategy::DiskFirst,
+            FlushPolicy::Immediate,
+            "test_reset_operation",
+        );
+        ctx.append_entries(1, 100, 1).await;
+
+        // Reset log
+        ctx.raft_log.reset().await.unwrap();
+
+        // Verify reset state
+        assert!(ctx.raft_log.is_empty());
+        assert_eq!(ctx.raft_log.durable_index.load(Ordering::Acquire), 0);
+        assert_eq!(ctx.raft_log.next_id.load(Ordering::Acquire), 1);
+    }
+}
+
+mod filter_out_conflicts_and_append_performance_tests {
+    use super::*;
+    use d_engine_server::FileStorageEngine;
+
+    #[tokio::test]
+    async fn test_filter_out_conflicts_performance_consistent_across_flush_intervals_fresh_cluster()
+    {
+        // Test configuration
+        let test_cases = vec![
+            (10, 50),   // 10ms interval, 50ms max duration
+            (100, 50),  // 100ms interval, 50ms max duration
+            (1000, 50), // 1000ms interval, 50ms max duration
+        ];
+
+        for (interval_ms, max_duration_ms) in test_cases {
+            // Create MemFirst storage with batch policy
+            let config = PersistenceConfig {
+                strategy: PersistenceStrategy::MemFirst,
+                flush_policy: FlushPolicy::Batch {
+                    threshold: 1000,
+                    interval_ms,
+                },
+                max_buffered_entries: 1000,
+                ..Default::default()
+            };
+
+            // let mut log_store = MockLogStore::new();
+            // log_store.expect_last_index().returning(|| 0);
+            // log_store.expect_truncate().returning(|_| Ok(()));
+            // log_store.expect_persist_entries().returning(|_| Ok(()));
+            // log_store.expect_reset().returning(|| Ok(()));
+
+            let temp_dir = tempdir().unwrap();
+            let path = temp_dir.path().to_path_buf();
+
+            let (log, receiver) = BufferedRaftLog::<
+                RaftTypeConfig<FileStorageEngine, MockStateMachine>,
+            >::new(
+                1, config, Arc::new(FileStorageEngine::new(path).unwrap())
+            );
+            let log = log.start(receiver);
+
+            // Populate with test data (1000 entries)
+            let mut entries = vec![];
+            for i in 1..=1000 {
+                entries.push(Entry {
+                    index: i,
+                    term: 1,
+                    payload: Some(EntryPayload::command(Bytes::from(vec![0; 256]))), // 256B payload
+                });
+            }
+            log.append_entries(entries.clone()).await.unwrap();
+
+            // Measure conflict resolution performance
+            let start = Instant::now();
+            log.filter_out_conflicts_and_append(
+                0, // prev_log_index
+                0, // prev_log_term
+                vec![Entry {
+                    index: 501,
+                    term: 1,
+                    payload: Some(EntryPayload::command(Bytes::from(vec![1; 256]))),
+                }],
+            )
+            .await
+            .unwrap();
+
+            let duration = start.elapsed().as_millis() as u64;
+            println!("Interval {interval_ms}ms: Took {duration}ms");
+
+            // Verify performance consistency
+            assert!(
+                duration <= max_duration_ms,
+                "Duration {duration}ms exceeds max {max_duration_ms}ms for {interval_ms}ms interval"
+            );
+
+            // Verify correctness
+            assert!(log.entry(500).unwrap().is_none());
+            assert!(log.entry(501).unwrap().is_some());
+            assert!(log.entry(502).unwrap().is_none());
+        }
+    }
+
+    #[tokio::test]
+    async fn test_filter_out_conflicts_performance_consistent_across_flush_intervals() {
+        // Test configuration
+        let test_cases = vec![
+            (10, 50),   // 10ms interval, 50ms max duration
+            (100, 50),  // 100ms interval, 50ms max duration
+            (1000, 50), // 1000ms interval, 50ms max duration
+        ];
+
+        for (interval_ms, max_duration_ms) in test_cases {
+            // Create MemFirst storage with batch policy
+            let config = PersistenceConfig {
+                strategy: PersistenceStrategy::MemFirst,
+                flush_policy: FlushPolicy::Batch {
+                    threshold: 1000,
+                    interval_ms,
+                },
+                max_buffered_entries: 1000,
+                ..Default::default()
+            };
+
+            let temp_dir = tempdir().unwrap();
+            let path = temp_dir.path().to_path_buf();
+
+            let (log, receiver) = BufferedRaftLog::<
+                RaftTypeConfig<FileStorageEngine, MockStateMachine>,
+            >::new(
+                1, config, Arc::new(FileStorageEngine::new(path).unwrap())
+            );
+            let log = log.start(receiver);
+
+            // Populate with test data (1000 entries)
+            let mut entries = vec![];
+            for i in 1..=1000 {
+                entries.push(Entry {
+                    index: i,
+                    term: 1,
+                    payload: Some(EntryPayload::command(Bytes::from(vec![0; 256]))), // 256B payload
+                });
+            }
+            log.append_entries(entries.clone()).await.unwrap();
+
+            // Measure conflict resolution performance
+            let start = Instant::now();
+            log.filter_out_conflicts_and_append(
+                500, // prev_log_index
+                1,   // prev_log_term
+                vec![Entry {
+                    index: 501,
+                    term: 1,
+                    payload: Some(EntryPayload::command(Bytes::from(vec![1; 256]))),
+                }],
+            )
+            .await
+            .unwrap();
+
+            let duration = start.elapsed().as_millis() as u64;
+            println!("Interval {interval_ms}ms: Took {duration}ms");
+
+            // Verify performance consistency
+            assert!(
+                duration <= max_duration_ms,
+                "Duration {duration}ms exceeds max {max_duration_ms}ms for {interval_ms}ms interval"
+            );
+
+            // Verify correctness
+            assert!(log.entry(500).unwrap().is_some());
+            assert!(log.entry(501).unwrap().is_some());
+            assert!(log.entry(502).unwrap().is_none()); // Conflict removed
+        }
+    }
+}
+
+mod performance_tests {
+    use std::sync::Arc;
+    use tokio::sync::Barrier;
+    use tokio::time::Duration;
+
+    use super::*;
+    use d_engine_core::MockLogStore;
+    use d_engine_core::MockMetaStore;
+    use d_engine_core::MockStorageEngine;
+
+    // Test helper: Creates storage with controllable delay
+    fn create_delayed_storage(delay_ms: u64) -> Arc<MockStorageEngine> {
+        let mut log_store = MockLogStore::new();
+        log_store.expect_last_index().returning(|| 0);
+        log_store.expect_truncate().returning(|_| Ok(()));
+        log_store.expect_reset().returning(|| Ok(()));
+        log_store.expect_flush().returning(|| Ok(()));
+
+        // Add controllable delay to persist_entries
+        log_store.expect_persist_entries().returning(move |_| {
+            let delay = Duration::from_millis(delay_ms);
+            std::thread::sleep(delay);
+            Ok(())
+        });
+
+        Arc::new(MockStorageEngine::from(log_store, MockMetaStore::new()))
+    }
+
+    // 1. Tests reset performance during active flush
+    #[tokio::test]
+    async fn test_reset_performance_during_active_flush() {
+        const FLUSH_DELAY_MS: u64 = 500;
+        let is_ci = std::env::var("CI").is_ok();
+        let max_reset_duration_ms = if is_ci { 500 } else { 50 };
+
+        let test_cases = vec![
+            (
+                PersistenceStrategy::MemFirst,
+                FlushPolicy::Batch {
+                    threshold: 1000,
+                    interval_ms: 1000,
+                },
+            ),
+            (PersistenceStrategy::DiskFirst, FlushPolicy::Immediate),
+        ];
+
+        for (strategy, flush_policy) in test_cases {
+            let storage = create_delayed_storage(FLUSH_DELAY_MS);
+            let config = PersistenceConfig {
+                strategy: strategy.clone(),
+                flush_policy: flush_policy.clone(),
+                max_buffered_entries: 1000,
+                ..Default::default()
+            };
+
+            let (log, receiver) = BufferedRaftLog::<MockTypeConfig>::new(1, config, storage);
+            let log_arc = Arc::new(log.start(receiver));
+            let barrier = Arc::new(Barrier::new(2));
+
+            // Start long-running flush in background
+            let flush_log = log_arc.clone();
+            let flush_barrier = barrier.clone();
+            tokio::spawn(async move {
+                let indexes: Vec<u64> = (1..=1000).collect();
+                flush_barrier.wait().await; // Sync point
+                let _ = flush_log.process_flush(&indexes).await;
+            });
+
+            // Wait for flush to start
+            barrier.wait().await;
+
+            // Measure reset performance during active flush
+            let start = Instant::now();
+            log_arc.reset().await.unwrap();
+            let duration = start.elapsed();
+
+            assert!(
+                duration.as_millis() < max_reset_duration_ms as u128,
+                "Reset took {}ms during active flush ({:?}/{:?})",
+                duration.as_millis(),
+                strategy,
+                flush_policy
+            );
+        }
+    }
+
+    // 2. Tests filter_out_conflicts performance with active flush
+    #[tokio::test]
+    async fn test_filter_conflicts_performance_during_flush() {
+        let is_ci = std::env::var("CI").is_ok();
+        // Relax time limit in CI environment
+        let test_cases = if is_ci {
+            vec![(10, 500), (100, 500), (1000, 500)]
+        } else {
+            vec![(10, 50), (100, 50), (1000, 50)]
+        };
+
+        const FLUSH_DELAY_MS: u64 = 300;
+        // const MAX_DURATION_MS: u64 = 50;
+
+        // let test_cases = vec![(10, 50), (100, 50), (1000, 50)];
+
+        for (interval_ms, max_duration_ms) in test_cases {
+            let storage = create_delayed_storage(FLUSH_DELAY_MS);
+            let config = PersistenceConfig {
+                strategy: PersistenceStrategy::MemFirst,
+                flush_policy: FlushPolicy::Batch {
+                    threshold: 1000,
+                    interval_ms,
+                },
+                max_buffered_entries: 1000,
+                ..Default::default()
+            };
+
+            let (log, receiver) = BufferedRaftLog::<MockTypeConfig>::new(1, config, storage);
+            let log_arc = Arc::new(log.start(receiver));
+            let barrier = Arc::new(Barrier::new(2));
+
+            // Populate with test data
+            let mut entries = vec![];
+            for i in 1..=1000 {
+                entries.push(Entry {
+                    index: i,
+                    term: 1,
+                    payload: Some(EntryPayload::command(Bytes::from(vec![0; 256]))),
+                });
+            }
+            log_arc.append_entries(entries).await.unwrap();
+
+            // Start long flush in background
+            let flush_log = log_arc.clone();
+            let flush_barrier = barrier.clone();
+            tokio::spawn(async move {
+                let indexes: Vec<u64> = (1..=1000).collect();
+                flush_barrier.wait().await;
+                let _ = flush_log.process_flush(&indexes).await;
+            });
+
+            // Wait for flush to start
+            barrier.wait().await;
+
+            // Measure performance during active flush
+            let start = Instant::now();
+            log_arc
+                .filter_out_conflicts_and_append(
+                    500,
+                    1,
+                    vec![Entry {
+                        index: 501,
+                        term: 1,
+                        payload: Some(EntryPayload::command(Bytes::from(vec![1; 256]))),
+                    }],
+                )
+                .await
+                .unwrap();
+
+            let duration = start.elapsed();
+            assert!(
+                duration.as_millis() < max_duration_ms as u128,
+                "Operation took {}ms with {}ms interval during flush",
+                duration.as_millis(),
+                interval_ms
+            );
+        }
+    }
+
+    // 3. Tests fresh cluster performance consistency
+    #[tokio::test]
+    async fn test_fresh_cluster_performance_consistency() {
+        let is_ci = std::env::var("CI").is_ok();
+        // Relax time limit in CI environment
+        let max_duration_ms = if is_ci { 50 } else { 5 };
+
+        let test_cases = vec![
+            (
+                PersistenceStrategy::MemFirst,
+                FlushPolicy::Batch {
+                    threshold: 1000,
+                    interval_ms: 1000,
+                },
+            ),
+            (PersistenceStrategy::DiskFirst, FlushPolicy::Immediate),
+        ];
+
+        for (strategy, flush_policy) in test_cases {
+            let mut log_store = MockLogStore::new();
+            log_store.expect_flush().return_once(|| Ok(()));
+            log_store.expect_last_index().returning(|| 0);
+            log_store.expect_truncate().returning(|_| Ok(()));
+            log_store.expect_persist_entries().returning(|_| Ok(()));
+            log_store.expect_reset().returning(|| Ok(()));
+
+            let config = PersistenceConfig {
+                strategy: strategy.clone(),
+                flush_policy: flush_policy.clone(),
+                max_buffered_entries: 1000,
+                ..Default::default()
+            };
+
+            let (log, receiver) = BufferedRaftLog::<MockTypeConfig>::new(
+                1,
+                config,
+                Arc::new(MockStorageEngine::from(log_store, MockMetaStore::new())),
+            );
+            let log_arc = Arc::new(log.start(receiver));
+
+            // Measure reset performance in fresh cluster
+            let start = Instant::now();
+            log_arc.reset().await.unwrap();
+            let duration = start.elapsed();
+
+            assert!(
+                duration.as_millis() < max_duration_ms as u128,
+                "Fresh cluster reset took {}ms ({:?}/{:?})",
+                duration.as_millis(),
+                strategy,
+                flush_policy
+            );
+        }
+    }
+
+    // // 4. Tests command processing during long flush
+    // #[tokio::test]
+    // async fn test_command_processing_during_flush() {
+    //     ;
+    //     const FLUSH_DELAY_MS: u64 = 800;
+    //     const MAX_COMMAND_DURATION_MS: u64 = 10;
+
+    //     let storage = create_delayed_storage(FLUSH_DELAY_MS);
+    //     let config = PersistenceConfig {
+    //         strategy: PersistenceStrategy::MemFirst,
+    //         flush_policy: FlushPolicy::Batch {
+    //             threshold: 1,
+    //             interval_ms: 1000,
+    //         },
+    //         max_buffered_entries: 1000,
+    //     };
+
+    //     let (log, mut receiver) = BufferedRaftLog::<MockTypeConfig>::new(1, config, storage);
+    //     let log_arc = Arc::new(log.start(receiver));
+    //     let barrier = Arc::new(Barrier::new(2));
+
+    //     // Start long-running flush
+    //     let flush_log = log_arc.clone();
+    //     let flush_barrier = barrier.clone();
+    //     tokio::spawn(async move {
+    //         let indexes = vec![1];
+    //         flush_barrier.wait().await;
+    //         let _ = flush_log.process_flush(&indexes).await;
+    //     });
+
+    //     // Wait for flush to start
+    //     barrier.wait().await;
+
+    //     // Test multiple command types during flush
+    //     let commands = vec![
+    //         LogCommand::Flush(oneshot::channel().0),
+    //         LogCommand::Reset(oneshot::channel().0),
+    //         LogCommand::PersistEntries(vec![2]),
+    //         LogCommand::WaitDurable(2, oneshot::channel().0),
+    //     ];
+
+    //     for cmd in commands {
+    //         let start = Instant::now();
+    //         log_arc.command_sender.send(cmd).unwrap();
+
+    //         // Verify command is processed quickly
+    //         match timeout(Duration::from_millis(MAX_COMMAND_DURATION_MS), receiver.recv()).await
+    // {             Ok(Some(_)) => {
+    //                 let duration = start.elapsed();
+    //                 assert!(
+    //                     duration.as_millis() < MAX_COMMAND_DURATION_MS as u128,
+    //                     "Command processing took {}ms during flush",
+    //                     duration.as_millis()
+    //                 );
+    //             }
+    //             _ => panic!("Command not processed within {}ms", MAX_COMMAND_DURATION_MS),
+    //         }
+    //     }
+    // }
+}
+
+mod batch_processor_tests {
+    use d_engine_server::LogCommand;
+    use std::sync::Arc;
+    use std::sync::atomic::AtomicBool;
+    use std::sync::atomic::Ordering;
+    use std::time::Duration;
+    use tokio::sync::Notify;
+    use tokio::sync::mpsc;
+    use tokio::sync::oneshot;
+
+    use super::*;
+
+    struct TestLog {
+        // Used to observe if reset was called
+        reset_called: Arc<AtomicBool>,
+        // Used to simulate slow flush
+        flush_notify: Arc<Notify>,
+        // Used to observe flush trigger
+        flush_triggered: Arc<AtomicBool>,
+    }
+
+    impl TestLog {
+        fn new() -> Self {
+            Self {
+                reset_called: Arc::new(AtomicBool::new(false)),
+                flush_notify: Arc::new(Notify::new()),
+                flush_triggered: Arc::new(AtomicBool::new(false)),
+            }
+        }
+    }
+
+    #[tokio::test]
+    async fn batch_processor_handles_command_while_flushing() {
+        // Setup
+        let test_log = TestLog::new();
+
+        // Simulate the actual struct with only what's needed for the test
+        struct DummyLog {
+            test_log: TestLog,
+        }
+        impl DummyLog {
+            async fn handle_command(
+                &self,
+                cmd: LogCommand,
+            ) {
+                if let LogCommand::Reset(_ack) = cmd {
+                    self.test_log.reset_called.store(true, Ordering::SeqCst);
+                }
+            }
+            async fn process_flush(
+                &self,
+                _indexes: &[u64],
+            ) -> Result<(), ()> {
+                self.test_log.flush_triggered.store(true, Ordering::SeqCst);
+                // Simulate slow flush
+                self.test_log.flush_notify.notified().await;
+                Ok(())
+            }
+            async fn get_pending_indexes(&self) -> Vec<u64> {
+                vec![1, 2, 3]
+            }
+        }
+
+        // Arc/Weak for test
+        let dummy_log = Arc::new(DummyLog { test_log });
+        let weak_log = Arc::downgrade(&dummy_log);
+
+        // Command channel
+        let (tx, mut rx) = mpsc::unbounded_channel();
+
+        // Spawn batch_processor (copied and adapted for test)
+        let flush_notify = dummy_log.test_log.flush_notify.clone();
+        let flush_triggered = dummy_log.test_log.flush_triggered.clone();
+        let reset_called = dummy_log.test_log.reset_called.clone();
+        let processor = tokio::spawn(async move {
+            let mut interval = tokio::time::interval(Duration::from_millis(50));
+            loop {
+                tokio::select! {
+                    cmd = rx.recv() => {
+                        if let Some(cmd) = cmd {
+                            if let Some(this) = weak_log.upgrade() {
+                                this.handle_command(cmd).await;
+                            }
+                        } else {
+                            break;
+                        }
+                    }
+                    _ = interval.tick() => {
+                        if let Some(this) = weak_log.upgrade() {
+                            let indexes = this.get_pending_indexes().await;
+                            if !indexes.is_empty() {
+                                let this_clone = Arc::clone(&this);
+                                tokio::spawn(async move {
+                                    let _ = this_clone.process_flush(&indexes).await;
+                                });
+                            }
+                        }
+                    }
+                }
+            }
+        });
+
+        // Send a command to trigger flush
+        tx.send(LogCommand::PersistEntries(vec![])).unwrap();
+
+        // Wait for flush to be triggered
+        tokio::time::timeout(Duration::from_millis(200), async {
+            while !flush_triggered.load(Ordering::SeqCst) {
+                tokio::time::sleep(Duration::from_millis(10)).await;
+            }
+        })
+        .await
+        .expect("Flush should be triggered");
+
+        // While flush is ongoing (not released), send Reset
+        let (one_tx, _one_rx) = oneshot::channel();
+        tx.send(LogCommand::Reset(one_tx)).unwrap();
+
+        // Wait a bit to let command process
+        tokio::time::sleep(Duration::from_millis(20)).await;
+
+        // Check that Reset was handled even while flush is not finished
+        assert!(
+            reset_called.load(Ordering::SeqCst),
+            "Reset command should be handled promptly"
+        );
+
+        // Release flush
+        flush_notify.notify_waiters();
+
+        // Cleanup: shutdown processor
+        drop(tx);
+        processor.await.unwrap();
+    }
+}
+
+mod save_load_hard_state_tests {
+    use super::*;
+    use d_engine_core::HardState;
+    use d_engine_core::LogStore;
+    use d_engine_core::MetaStore;
+    use d_engine_core::StorageEngine;
+    use d_engine_proto::server::election::VotedFor;
+    use d_engine_server::FileStorageEngine;
+
+    /// Test that hard state operations use the meta tree and not the log tree
+    #[tokio::test]
+    async fn test_hard_state_uses_meta_tree_not_log_tree() {
+        let context = TestContext::new(
+            PersistenceStrategy::MemFirst,
+            FlushPolicy::Batch {
+                threshold: 1,
+                interval_ms: 1,
+            },
+            "test_hard_state_uses_meta_tree_not_log_tree",
+        );
+
+        // Create test hard state
+        let test_hard_state = HardState {
+            current_term: 5,
+            voted_for: Some(VotedFor {
+                voted_for_id: 10,
+                voted_for_term: 7,
+            }),
+        };
+
+        // Save through buffered raft log
+        context
+            .raft_log
+            .save_hard_state(&test_hard_state)
+            .expect("save_hard_state should succeed");
+
+        // Verify storage engine state
+        // 1. Meta tree should contain the hard state
+        let decoded_meta = context
+            .storage
+            .meta_store()
+            .load_hard_state()
+            .expect("meta_tree.get should succeed")
+            .expect("hard state should exist in meta tree");
+
+        // let decoded_meta: HardState = bincode::deserialize(&meta_value).unwrap();
+        assert_eq!(decoded_meta.current_term, 5);
+        assert_eq!(
+            decoded_meta.voted_for,
+            Some(VotedFor {
+                voted_for_id: 10,
+                voted_for_term: 7,
+            })
+        );
+
+        // // 2. Log tree should NOT contain the hard state key
+        // let log_value = context
+        //     .storage
+        //     .log_store()
+        //     .get(HARD_STATE_KEY)
+        //     .expect("log_tree.get should succeed");
+        // assert!(
+        //     log_value.is_none(),
+        //     "Hard state key should not exist in log tree"
+        // );
+
+        // 3. Load through buffered raft log
+        let loaded = context
+            .raft_log
+            .load_hard_state()
+            .expect("load_hard_state should succeed")
+            .expect("hard state should exist");
+        assert_eq!(loaded.current_term, 5);
+        assert_eq!(
+            loaded.voted_for,
+            Some(VotedFor {
+                voted_for_id: 10,
+                voted_for_term: 7,
+            })
+        );
+    }
+
+    /// Test that hard state survives restarts and uses the correct tree
+    #[tokio::test]
+    async fn test_hard_state_persistence_across_restart() {
+        let node_id = 1;
+
+        let tempdir = tempfile::tempdir().unwrap();
+        let file_path = tempdir.path().to_path_buf();
+        // Phase 1: Initial save
+        {
+            let storage = Arc::new(FileStorageEngine::new(file_path.clone()).unwrap());
+            let (raft_log, receiver) =
+                BufferedRaftLog::<RaftTypeConfig<FileStorageEngine, MockStateMachine>>::new(
+                    node_id,
+                    PersistenceConfig {
+                        strategy: PersistenceStrategy::MemFirst,
+                        flush_policy: FlushPolicy::Immediate,
+                        max_buffered_entries: 1000,
+                        ..Default::default()
+                    },
+                    storage,
+                );
+            let raft_log = raft_log.start(receiver);
+
+            let hard_state = HardState {
+                current_term: 8,
+                voted_for: Some(VotedFor {
+                    voted_for_id: 3,
+                    voted_for_term: 8,
+                }),
+            };
+            raft_log.save_hard_state(&hard_state).expect("save should succeed");
+
+            // Explicitly flush to ensure data is persisted
+            raft_log.log_store.flush().expect("flush should succeed");
+            raft_log.meta_store.flush().expect("flush should succeed");
+        }
+
+        // Phase 2: Restart
+        {
+            let storage = Arc::new(FileStorageEngine::new(file_path).unwrap());
+            let (raft_log, receiver) =
+                BufferedRaftLog::<RaftTypeConfig<FileStorageEngine, MockStateMachine>>::new(
+                    node_id,
+                    PersistenceConfig {
+                        strategy: PersistenceStrategy::MemFirst,
+                        flush_policy: FlushPolicy::Immediate,
+                        max_buffered_entries: 1000,
+                        ..Default::default()
+                    },
+                    storage,
+                );
+            let raft_log = raft_log.start(receiver);
+
+            // Verify hard state loaded correctly
+            let loaded = raft_log
+                .load_hard_state()
+                .expect("load should succeed")
+                .expect("state should exist");
+            assert_eq!(loaded.current_term, 8);
+            assert_eq!(
+                loaded.voted_for,
+                Some(VotedFor {
+                    voted_for_id: 3,
+                    voted_for_term: 8,
+                })
+            );
+
+            // Verify storage trees
+            // 1. Meta tree should contain the value
+            // let meta_value = raft_log
+            //     .meta_store
+            //     .get(HARD_STATE_KEY)
+            //     .expect("meta get should succeed")
+            //     .expect("value should exist");
+            // let decoded: HardState = bincode::deserialize(&meta_value).unwrap();
+            // assert_eq!(decoded.current_term, 8);
+
+            // // 2. Log tree should NOT contain the value
+            // let log_value =
+            //     raft_log.meta_store.get(HARD_STATE_KEY).expect("log get should succeed");
+            // assert!(log_value.is_none(), "Hard state should not be in log tree");
+        }
+    }
+
+    /// Test that reset operation doesn't clear hard state (only log tree)
+    #[tokio::test]
+    async fn test_reset_preserves_hard_state() {
+        let context = TestContext::new(
+            PersistenceStrategy::MemFirst,
+            FlushPolicy::Batch {
+                threshold: 1,
+                interval_ms: 1,
+            },
+            "test_reset_preserves_hard_state",
+        );
+
+        // Save initial hard state
+        let hs = HardState {
+            current_term: 3,
+            voted_for: Some(VotedFor {
+                voted_for_id: 5,
+                voted_for_term: 7,
+            }),
+        };
+        context.raft_log.save_hard_state(&hs).expect("save should succeed");
+
+        // Perform reset (should only clear logs)
+        context.raft_log.reset().await.expect("reset should succeed");
+
+        // Verify hard state still exists
+        let loaded = context.raft_log.load_hard_state().expect("load should succeed").unwrap();
+        assert_eq!(loaded.current_term, 3);
+        assert_eq!(
+            loaded.voted_for,
+            Some(VotedFor {
+                voted_for_id: 5,
+                voted_for_term: 7,
+            })
+        );
+
+        // Verify meta tree still has the data
+        // let meta_value = context
+        //     .storage
+        //     .meta_store()
+        //     .get(HARD_STATE_KEY)
+        //     .expect("meta get should succeed")
+        //     .expect("value should exist");
+        // assert!(!meta_value.is_empty());
+    }
+}
+
+#[tokio::test]
+#[traced_test]
+async fn test_last_entry_id_performance() {
+    // Set up test context
+    let test_context = TestContext::new(
+        PersistenceStrategy::MemFirst,
+        FlushPolicy::Batch {
+            threshold: 1_000_000,
+            interval_ms: 360_000,
+        },
+        "test_last_entry_id_performance",
+    );
+
+    // Create a large number of entries
+    const ENTRY_COUNT: usize = 1_000_000;
+    let entries: Vec<_> = (0..ENTRY_COUNT)
+        .map(|index| Entry {
+            index: index as u64,
+            term: index as u64,
+            payload: Some(EntryPayload::command(Bytes::from(vec![1; 256]))),
+        })
+        .collect();
+
+    // Insert entries into the log
+    let insert_start = Instant::now();
+    test_context.raft_log.append_entries(entries).await.unwrap();
+    let insert_duration = insert_start.elapsed();
+    println!("Insert duration: {insert_duration:?}");
+
+    // Measure last_entry_id performance
+    let mut durations = Vec::with_capacity(10);
+    let mut last_id = 0;
+    for _ in 1..1_000 {
+        let start = Instant::now();
+        last_id = test_context.raft_log.last_entry_id();
+        let duration = start.elapsed();
+        durations.push(duration);
+    }
+
+    // Calculate average duration
+    let avg_duration = durations.iter().sum::<Duration>() / durations.len() as u32;
+    println!("Average last_entry_id duration: {avg_duration:?}");
+    assert!(avg_duration < Duration::from_millis(1));
+    // Assert that the last entry ID is correct
+    assert_eq!(last_id, ENTRY_COUNT as u64 - 1);
+}
+
+#[cfg(test)]
+mod remove_range_tests {
+    use super::*;
+    use d_engine_server::test_utils;
+
+    #[tokio::test]
+    async fn test_remove_middle_range() {
+        let context = TestContext::new(
+            PersistenceStrategy::MemFirst,
+            FlushPolicy::Batch {
+                threshold: 1,
+                interval_ms: 1,
+            },
+            "test_remove_middle_range",
+        );
+        context.raft_log.reset().await.expect("reset successfully!");
+
+        // Insert 100 entries
+        test_utils::simulate_insert_command(&context.raft_log, (1..=100).collect(), 1).await;
+        assert_eq!(context.raft_log.len(), 100);
+        assert_eq!(context.raft_log.first_entry_id(), 1);
+        assert_eq!(context.raft_log.last_entry_id(), 100);
+
+        // Remove middle range
+        context.raft_log.remove_range(40..=60);
+
+        // Verify removal
+        assert_eq!(context.raft_log.len(), 79);
+        assert_eq!(context.raft_log.first_entry_id(), 1); // Min unchanged
+        assert_eq!(context.raft_log.last_entry_id(), 100); // Max unchanged
+
+        // Verify specific entries
+        assert!(context.raft_log.entry(39).unwrap().is_some());
+        assert!(context.raft_log.entry(40).unwrap().is_none());
+        assert!(context.raft_log.entry(60).unwrap().is_none());
+        assert!(context.raft_log.entry(61).unwrap().is_some());
+    }
+
+    #[tokio::test]
+    async fn test_remove_from_start() {
+        let context = TestContext::new(
+            PersistenceStrategy::MemFirst,
+            FlushPolicy::Batch {
+                threshold: 1,
+                interval_ms: 1,
+            },
+            "test_remove_from_start",
+        );
+        context.raft_log.reset().await.expect("reset successfully!");
+
+        // Insert 100 entries
+        test_utils::simulate_insert_command(&context.raft_log, (1..=100).collect(), 1).await;
+
+        // Remove first 50 entries
+        context.raft_log.remove_range(1..=50);
+
+        // Verify state
+        assert_eq!(context.raft_log.len(), 50);
+        assert_eq!(context.raft_log.first_entry_id(), 51); // Min updated
+        assert_eq!(context.raft_log.last_entry_id(), 100); // Max unchanged
+
+        // Boundary checks
+        assert!(context.raft_log.entry(50).unwrap().is_none());
+        assert!(context.raft_log.entry(51).unwrap().is_some());
+    }
+
+    #[tokio::test]
+    async fn test_remove_to_end() {
+        let context = TestContext::new(
+            PersistenceStrategy::MemFirst,
+            FlushPolicy::Batch {
+                threshold: 1,
+                interval_ms: 1,
+            },
+            "test_remove_to_end",
+        );
+        context.raft_log.reset().await.expect("reset successfully!");
+
+        // Insert 100 entries
+        test_utils::simulate_insert_command(&context.raft_log, (1..=100).collect(), 1).await;
+
+        // Remove from 90 to end
+        context.raft_log.remove_range(90..=u64::MAX);
+
+        // Verify state
+        assert_eq!(context.raft_log.len(), 89);
+        assert_eq!(context.raft_log.first_entry_id(), 1); // Min unchanged
+        assert_eq!(context.raft_log.last_entry_id(), 89); // Max updated
+
+        // Boundary checks
+        assert!(context.raft_log.entry(89).unwrap().is_some());
+        assert!(context.raft_log.entry(90).unwrap().is_none());
+        assert!(context.raft_log.entry(100).unwrap().is_none());
+    }
+
+    #[tokio::test]
+    async fn test_remove_empty_range() {
+        let context = TestContext::new(
+            PersistenceStrategy::MemFirst,
+            FlushPolicy::Batch {
+                threshold: 1,
+                interval_ms: 1,
+            },
+            "test_remove_empty_range",
+        );
+        context.raft_log.reset().await.expect("reset successfully!");
+
+        test_utils::simulate_insert_command(&context.raft_log, vec![1, 2, 3], 1).await;
+
+        // Remove nothing
+        context.raft_log.remove_range(5..=10);
+
+        assert_eq!(context.raft_log.len(), 3);
+        assert_eq!(context.raft_log.first_entry_id(), 1);
+        assert_eq!(context.raft_log.last_entry_id(), 3);
+    }
+
+    #[tokio::test]
+    async fn test_remove_entire_log() {
+        let context = TestContext::new(
+            PersistenceStrategy::MemFirst,
+            FlushPolicy::Batch {
+                threshold: 1,
+                interval_ms: 1,
+            },
+            "test_remove_entire_log",
+        );
+        context.raft_log.reset().await.expect("reset successfully!");
+
+        // Insert 100 entries
+        test_utils::simulate_insert_command(&context.raft_log, (1..=100).collect(), 1).await;
+
+        // Remove entire log
+        context.raft_log.remove_range(1..=u64::MAX);
+
+        // Verify state
+        assert_eq!(context.raft_log.len(), 0);
+        assert_eq!(context.raft_log.first_entry_id(), 0);
+        assert_eq!(context.raft_log.last_entry_id(), 0);
+        assert!(context.raft_log.is_empty());
+    }
+
+    #[tokio::test]
+    async fn test_remove_range_with_concurrent_reads() {
+        let context = TestContext::new(
+            PersistenceStrategy::MemFirst,
+            FlushPolicy::Batch {
+                threshold: 1,
+                interval_ms: 1,
+            },
+            "test_remove_range_with_concurrent_reads",
+        );
+        context.raft_log.reset().await.expect("reset successfully!");
+
+        // Insert 1000 entries
+        test_utils::simulate_insert_command(&context.raft_log, (1..=1000).collect(), 1).await;
+
+        // Spawn concurrent readers
+        let readers: Vec<_> = (0..10)
+            .map(|_| {
+                let log = context.raft_log.clone();
+                tokio::spawn(async move {
+                    for i in 1..=1000 {
+                        // This shouldn't panic even during removal
+                        let _ = log.entry(i);
+                    }
+                })
+            })
+            .collect();
+
+        // Remove a large range while reads are happening
+        context.raft_log.remove_range(300..=700);
+
+        // Wait for readers to finish
+        for handle in readers {
+            handle.await.expect("reader task failed");
+        }
+
+        // Verify final state
+        assert_eq!(context.raft_log.len(), 599); // 299 before + 300 after
+        assert!(context.raft_log.entry(299).unwrap().is_some());
+        assert!(context.raft_log.entry(300).unwrap().is_none());
+        assert!(context.raft_log.entry(700).unwrap().is_none());
+        assert!(context.raft_log.entry(701).unwrap().is_some());
+    }
+
+    #[tokio::test]
+    async fn test_remove_range_performance() {
+        // Skip performance tests during coverage runs due to instrumentation overhead
+        if std::env::var("CARGO_LLVM_COV").is_ok() || std::env::var("CARGO_TARPAULIN").is_ok() {
+            eprintln!("Skipping performance test during coverage run");
+            return;
+        }
+
+        let context = TestContext::new(
+            PersistenceStrategy::MemFirst,
+            FlushPolicy::Batch {
+                threshold: 1,
+                interval_ms: 1,
+            },
+            "test_remove_range_performance",
+        );
+        context.raft_log.reset().await.expect("reset successfully!");
+
+        // Insert 100,000 entries
+        let entries: Vec<u64> = (1..=100_000).collect();
+        test_utils::simulate_insert_command(&context.raft_log, entries, 1).await;
+
+        // Measure removal of 50,000 entries
+        let start = std::time::Instant::now();
+        context.raft_log.remove_range(25_001..=75_000);
+        let duration = start.elapsed();
+
+        println!("Removed 50,000 entries in {duration:?}");
+        assert!(duration < std::time::Duration::from_millis(100));
+
+        // Verify state
+        assert_eq!(context.raft_log.len(), 50_000);
+        assert_eq!(
+            context.raft_log.entry(25_000).unwrap().unwrap().index,
+            25_000
+        );
+        assert!(context.raft_log.entry(25_001).unwrap().is_none());
+        assert!(context.raft_log.entry(75_000).unwrap().is_none());
+        assert_eq!(
+            context.raft_log.entry(75_001).unwrap().unwrap().index,
+            75_001
+        );
+    }
+
+    #[tokio::test]
+    async fn test_remove_single_entry() {
+        let context = TestContext::new(
+            PersistenceStrategy::MemFirst,
+            FlushPolicy::Batch {
+                threshold: 1,
+                interval_ms: 1,
+            },
+            "test_remove_single_entry",
+        );
+        context.raft_log.reset().await.expect("reset successfully!");
+
+        test_utils::simulate_insert_command(&context.raft_log, vec![1, 2, 3], 1).await;
+
+        // Remove middle entry
+        context.raft_log.remove_range(2..=2);
+
+        assert_eq!(context.raft_log.len(), 2);
+        assert_eq!(context.raft_log.first_entry_id(), 1);
+        assert_eq!(context.raft_log.last_entry_id(), 3);
+        assert!(context.raft_log.entry(2).unwrap().is_none());
+    }
+}
+
+// Add these tests to cover important edge cases and performance scenarios
+
+#[tokio::test]
+#[traced_test]
+async fn test_high_concurrency_mixed_operations() {
+    let ctx = TestContext::new(
+        PersistenceStrategy::MemFirst,
+        FlushPolicy::Batch {
+            threshold: 1000,
+            interval_ms: 100,
+        },
+        "test_high_concurrency_mixed_operations",
+    );
+
+    let mut handles = vec![];
+    let start_time = Instant::now();
+
+    // Spawn concurrent writers
+    for i in 0..10 {
+        let log = ctx.raft_log.clone();
+        handles.push(tokio::spawn(async move {
+            for j in 1..=1000 {
+                let entry = Entry {
+                    index: (i * 1000) + j,
+                    term: 1,
+                    payload: Some(EntryPayload::command(Bytes::from(vec![0; 1024]))), // 1KB payload
+                };
+                log.append_entries(vec![entry]).await.unwrap();
+            }
+        }));
+    }
+
+    // Spawn concurrent readers
+    for _ in 0..5 {
+        let log = ctx.raft_log.clone();
+        handles.push(tokio::spawn(async move {
+            for _ in 0..500 {
+                let last_index = log.last_entry_id();
+                if last_index > 0 {
+                    let _ = log.get_entries_range(1..=last_index.min(100));
+                }
+                tokio::time::sleep(Duration::from_micros(10)).await;
+            }
+        }));
+    }
+
+    // Spawn concurrent term queries
+    for _ in 0..3 {
+        let log = ctx.raft_log.clone();
+        handles.push(tokio::spawn(async move {
+            for _ in 0..300 {
+                let _ = log.first_index_for_term(1);
+                let _ = log.last_index_for_term(1);
+                tokio::time::sleep(Duration::from_micros(15)).await;
+            }
+        }));
+    }
+
+    for handle in handles {
+        handle.await.unwrap();
+    }
+
+    let duration = start_time.elapsed();
+    println!("Mixed operations completed in: {duration:?}");
+
+    // Verify data integrity
+    assert_eq!(ctx.raft_log.len(), 10000);
+    assert!(
+        duration < Duration::from_secs(10),
+        "Operations took too long: {duration:?}"
+    );
+}
+
+#[tokio::test]
+#[traced_test]
+async fn test_extreme_boundary_conditions() {
+    let ctx = TestContext::new(
+        PersistenceStrategy::DiskFirst,
+        FlushPolicy::Immediate,
+        "test_extreme_boundary_conditions",
+    );
+
+    // Test with maximum index values
+    let max_index = u64::MAX - 10;
+    let entries = vec![
+        Entry {
+            index: max_index,
+            term: 1,
+            payload: Some(EntryPayload::command(Bytes::from(b"max_data".to_vec()))),
+        },
+        Entry {
+            index: max_index + 1,
+            term: 1,
+            payload: Some(EntryPayload::command(Bytes::from(b"max_data+1".to_vec()))),
+        },
+    ];
+
+    ctx.raft_log.append_entries(entries).await.unwrap();
+
+    // Verify extreme values are handled correctly
+    assert_eq!(ctx.raft_log.last_entry_id(), max_index + 1);
+    assert!(ctx.raft_log.entry(max_index).unwrap().is_some());
+    assert!(ctx.raft_log.entry(max_index + 1).unwrap().is_some());
+}
+
+#[tokio::test]
+#[traced_test]
+async fn test_recovery_under_different_scenarios() {
+    // Test various recovery scenarios
+    let scenarios = vec![
+        // MemFirst with Immediate flush - should persist everything
+        (PersistenceStrategy::MemFirst, FlushPolicy::Immediate, 100),
+        // MemFirst with batch flushing - only persists when threshold met
+        (
+            PersistenceStrategy::MemFirst,
+            FlushPolicy::Batch {
+                threshold: 50,
+                interval_ms: 10,
+            },
+            100,
+        ),
+        (
+            PersistenceStrategy::MemFirst,
+            FlushPolicy::Batch {
+                threshold: 200,
+                interval_ms: 10,
+            },
+            0,
+        ),
+        // DiskFirst should always persist
+        (PersistenceStrategy::DiskFirst, FlushPolicy::Immediate, 100),
+    ];
+
+    for (strategy, flush_policy, expected_recovery) in scenarios {
+        let instance_id = format!("recovery_test_{strategy:?}_{flush_policy:?}");
+        let original_ctx = TestContext::new(strategy.clone(), flush_policy.clone(), &instance_id);
+
+        // Add test data
+        for i in 1..=100 {
+            original_ctx
+                .raft_log
+                .append_entries(vec![Entry {
+                    index: i,
+                    term: 1,
+                    payload: Some(EntryPayload::command(Bytes::from(
+                        format!("data{i}").into_bytes(),
+                    ))),
+                }])
+                .await
+                .unwrap();
+        }
+
+        // For DiskFirst and Immediate flush, explicitly flush to ensure persistence
+        if matches!(strategy, PersistenceStrategy::DiskFirst)
+            || matches!(flush_policy, FlushPolicy::Immediate)
+        {
+            original_ctx.raft_log.flush().await.unwrap();
+        } else if let FlushPolicy::Batch { threshold, .. } = flush_policy {
+            // For batch policy, only flush if we reached the threshold
+            if 100 >= threshold {
+                original_ctx.raft_log.flush().await.unwrap();
+                tokio::time::sleep(Duration::from_millis(100)).await; // KEY!!!
+            }
+        }
+
+        // Simulate crash and recovery
+        let recovered_ctx = original_ctx.recover_from_crash();
+        drop(original_ctx);
+
+        // Verify recovery based on expected behavior
+        assert_eq!(
+            recovered_ctx.raft_log.len(),
+            expected_recovery,
+            "Recovery mismatch for strategy {strategy:?} policy {flush_policy:?}"
+        );
+    }
+}
+
+#[tokio::test]
+#[traced_test]
+async fn test_performance_benchmarks() {
+    // Skip performance tests during coverage runs due to instrumentation overhead
+    if std::env::var("CARGO_LLVM_COV").is_ok() || std::env::var("CARGO_TARPAULIN").is_ok() {
+        eprintln!("Skipping performance test during coverage run");
+        return;
+    }
+
+    let is_ci = std::env::var("CI").is_ok();
+
+    // Adjust test parameters according to the environment
+    let operations = if is_ci {
+        // CI environment uses a more relaxed threshold
+        [
+            ("append_entries", 500, 500.0),
+            ("get_entries_range", 2500, 25000.0),
+            ("entry_lookup", 5000, 100000.0),
+            ("term_queries", 4000, 25000.0),
+        ]
+    } else {
+        // Local environment uses a stricter threshold
+        [
+            ("append_entries", 1000, 1000.0),
+            ("get_entries_range", 5000, 50000.0),
+            ("entry_lookup", 10000, 200000.0),
+            ("term_queries", 8000, 50000.0),
+        ]
+    };
+
+    let ctx = TestContext::new(
+        PersistenceStrategy::MemFirst,
+        FlushPolicy::Batch {
+            threshold: 1000,
+            interval_ms: 100,
+        },
+        "performance_benchmark",
+    );
+
+    // Pre-populate with data
+    let mut entries = Vec::new();
+    // Reduce pre-population data in a CI environment
+    let pre_populate_count = if is_ci { 5000 } else { 10000 };
+
+    for i in 1..=pre_populate_count {
+        entries.push(Entry {
+            index: i,
+            term: i / 100 + 1, // Vary terms
+            payload: Some(EntryPayload::command(Bytes::from(vec![0; 256]))), // 256B payload
+        });
+    }
+    ctx.raft_log.append_entries(entries).await.unwrap();
+
+    let mut results = HashMap::new();
+
+    for (op_name, count, min_ops_per_sec) in operations {
+        let start = Instant::now();
+
+        match op_name {
+            "append_entries" => {
+                for i in 0..count {
+                    let entry = Entry {
+                        index: 10000 + i as u64 + 1,
+                        term: 101,
+                        payload: Some(EntryPayload::command(Bytes::from(vec![0; 256]))),
+                    };
+                    ctx.raft_log.append_entries(vec![entry]).await.unwrap();
+                }
+            }
+            "get_entries_range" => {
+                for i in 0..count {
+                    let start_idx = (i % 9000) as u64 + 1;
+                    let end_idx = start_idx + 100;
+                    let _ = ctx.raft_log.get_entries_range(start_idx..=end_idx);
+                }
+            }
+            "entry_lookup" => {
+                for i in 0..count {
+                    let index = (i % 10000) as u64 + 1;
+                    let _ = ctx.raft_log.entry(index);
+                }
+            }
+            "term_queries" => {
+                for i in 0..count {
+                    let term = (i % 100) as u64 + 1;
+                    let _ = ctx.raft_log.first_index_for_term(term);
+                    let _ = ctx.raft_log.last_index_for_term(term);
+                }
+            }
+            _ => {}
+        }
+
+        let duration = start.elapsed();
+        let ops_per_sec = count as f64 / duration.as_secs_f64();
+        results.insert(op_name, (duration, ops_per_sec));
+
+        println!("{op_name}: {count} operations in {duration:?} ({ops_per_sec:.2} ops/sec)");
+
+        // Performance assertions with more realistic thresholds
+        assert!(
+            ops_per_sec > min_ops_per_sec,
+            "{op_name} operations too slow: {ops_per_sec:.2} ops/sec (expected > {min_ops_per_sec:.2})"
+        );
+    }
+}
+
+#[tokio::test]
+async fn test_worker_retry_survives_transient_errors() {
+    // Tests fix for Issue B: Worker exits prematurely after retry
+    let ctx = TestContext::new(
+        PersistenceStrategy::MemFirst,
+        FlushPolicy::Batch {
+            threshold: 10,
+            interval_ms: 50,
+        },
+        "test_worker_retry_survives",
+    );
+
+    // Append entries that will trigger flush
+    for i in 1..=100 {
+        ctx.append_entries(i, 1, 1).await;
+    }
+
+    // Wait for flush workers to process
+    tokio::time::sleep(Duration::from_millis(200)).await;
+
+    // Verify all workers are still alive by checking continued processing
+    ctx.append_entries(101, 50, 1).await;
+    tokio::time::sleep(Duration::from_millis(100)).await;
+
+    assert_eq!(ctx.raft_log.last_entry_id(), 150);
+}
+
+#[tokio::test]
+async fn test_durable_index_monotonic_under_concurrency() {
+    let ctx = TestContext::new(
+        PersistenceStrategy::MemFirst,
+        FlushPolicy::Immediate,
+        "test_durable_index_monotonic",
+    );
+
+    let mut handles = vec![];
+
+    for batch in 0..10 {
+        let log = ctx.raft_log.clone();
+        handles.push(tokio::spawn(async move {
+            let start = batch * 100 + 1;
+            let entries: Vec<Entry> = (start..start + 100)
+                .map(|i| Entry {
+                    index: i,
+                    term: 1,
+                    payload: None,
+                })
+                .collect();
+            log.append_entries(entries).await.unwrap();
+        }));
+    }
+
+    join_all(handles).await;
+
+    // Wait for flush to complete
+    tokio::time::sleep(Duration::from_millis(200)).await;
+
+    // Verify monotonicity
+    let durable = ctx.raft_log.durable_index.load(Ordering::Acquire);
+    assert!(durable >= 1000, "durable_index should reach max value");
+
+    // Verify no entries lost
+    assert_eq!(ctx.raft_log.len(), 1000);
+}
+
+#[tokio::test]
+async fn test_shutdown_closes_channel_properly() {
+    // Better approach: Test shutdown through Drop behavior
+    let node_id = 1;
+    let temp_dir = tempdir().unwrap();
+    let path = temp_dir.path().to_path_buf();
+
+    let _worker_handles = {
+        let storage = Arc::new(FileStorageEngine::new(path.clone()).unwrap());
+        let (raft_log, receiver) =
+            BufferedRaftLog::<RaftTypeConfig<FileStorageEngine, MockStateMachine>>::new(
+                node_id,
+                PersistenceConfig {
+                    strategy: PersistenceStrategy::MemFirst,
+                    flush_policy: FlushPolicy::Batch {
+                        threshold: 10,
+                        interval_ms: 100,
+                    },
+                    max_buffered_entries: 1000,
+                    ..Default::default()
+                },
+                storage,
+            );
+        let raft_log = raft_log.start(receiver);
+
+        // Add some entries
+        for i in 1..=10 {
+            raft_log
+                .append_entries(vec![Entry {
+                    index: i,
+                    term: 1,
+                    payload: None,
+                }])
+                .await
+                .unwrap();
+        }
+
+        // Extract worker handles before drop
+        let handles: Vec<_> =
+            raft_log.flush_workers.worker_handles.iter().map(|h| h.is_finished()).collect();
+
+        // Trigger shutdown via Drop
+        drop(raft_log);
+
+        handles
+    };
+
+    // Wait for shutdown to complete
+    tokio::time::sleep(Duration::from_millis(200)).await;
+}
+
+// ========== RAFT CORRECTNESS TESTS ==========
+
+#[tokio::test]
+async fn test_memfirst_crash_recovery_durability() {
+    let instance_id = "test_memfirst_durability";
+
+    let recovered_path = {
+        let ctx = TestContext::new(
+            PersistenceStrategy::MemFirst,
+            FlushPolicy::Batch {
+                threshold: 1000, // High threshold to prevent auto-flush
+                interval_ms: 10000,
+            },
+            instance_id,
+        );
+
+        ctx.append_entries(1, 100, 1).await;
+
+        // Verify visible in memory
+        assert_eq!(ctx.raft_log.len(), 100);
+
+        let path = ctx.path.clone();
+        // Simulate crash WITHOUT flush
+        drop(ctx);
+        path
+    };
+
+    tokio::time::sleep(Duration::from_millis(50)).await;
+
+    // Recovery
+    let storage = Arc::new(FileStorageEngine::new(PathBuf::from(&recovered_path)).unwrap());
+    let (raft_log, receiver) =
+        BufferedRaftLog::<RaftTypeConfig<FileStorageEngine, MockStateMachine>>::new(
+            1,
+            PersistenceConfig {
+                strategy: PersistenceStrategy::MemFirst,
+                flush_policy: FlushPolicy::Immediate,
+                max_buffered_entries: 1000,
+                ..Default::default()
+            },
+            storage,
+        );
+    let raft_log = raft_log.start(receiver);
+
+    tokio::time::sleep(Duration::from_millis(50)).await;
+
+    // After crash without flush, data should be lost
+    assert_eq!(
+        raft_log.len(),
+        0,
+        "MemFirst without flush should lose uncommitted data"
+    );
+}
+
+#[tokio::test]
+async fn test_diskfirst_crash_recovery_durability() {
+    let temp_dir = tempfile::tempdir().unwrap();
+    let instance_id = "test_diskfirst_durability";
+    let storage_path = temp_dir.path().join(instance_id);
+
+    let ctx1 = {
+        let storage = Arc::new(FileStorageEngine::new(storage_path.clone()).unwrap());
+        let (raft_log, receiver) =
+            BufferedRaftLog::<RaftTypeConfig<FileStorageEngine, MockStateMachine>>::new(
+                1,
+                PersistenceConfig {
+                    strategy: PersistenceStrategy::DiskFirst,
+                    flush_policy: FlushPolicy::Immediate,
+                    max_buffered_entries: 1000,
+                    ..Default::default()
+                },
+                storage,
+            );
+        let raft_log = raft_log.start(receiver);
+
+        let entries: Vec<_> = (1..1 + 100)
+            .map(|index| Entry {
+                index,
+                term: 1,
+                payload: Some(EntryPayload::command(Bytes::from(b"data".to_vec()))),
+            })
+            .collect();
+
+        raft_log.append_entries(entries).await.unwrap();
+        raft_log.flush().await.unwrap();
+        assert_eq!(raft_log.len(), 100, "All entries should be recovered");
+
+        raft_log
+    };
+
+    drop(ctx1);
+    tokio::time::sleep(Duration::from_millis(100)).await;
+
+    // Phase 2: Recovery
+    let storage = Arc::new(FileStorageEngine::new(PathBuf::from(&storage_path)).unwrap());
+    let (raft_log, receiver) =
+        BufferedRaftLog::<RaftTypeConfig<FileStorageEngine, MockStateMachine>>::new(
+            1,
+            PersistenceConfig {
+                strategy: PersistenceStrategy::DiskFirst,
+                flush_policy: FlushPolicy::Immediate,
+                max_buffered_entries: 1000,
+                ..Default::default()
+            },
+            storage,
+        );
+    let raft_log = raft_log.start(receiver);
+
+    tokio::time::sleep(Duration::from_millis(50)).await;
+
+    // Verify recovery
+    assert_eq!(raft_log.len(), 100, "All entries should be recovered");
+    assert_eq!(
+        raft_log.durable_index.load(Ordering::Acquire),
+        100,
+        "Durable index should be 100"
+    );
+}
+
+#[tokio::test]
+async fn test_log_matching_property() {
+    let ctx = TestContext::new(
+        PersistenceStrategy::DiskFirst,
+        FlushPolicy::Immediate,
+        "test_log_matching",
+    );
+
+    // Build log: [1,1] [2,1] [3,2] [4,2] [5,3]
+    ctx.append_entries(1, 2, 1).await;
+    ctx.append_entries(3, 2, 2).await;
+    ctx.append_entries(5, 1, 3).await;
+
+    // Verify consistency
+    assert_eq!(ctx.raft_log.entry_term(3), Some(2));
+    assert_eq!(ctx.raft_log.first_index_for_term(2), Some(3));
+    assert_eq!(ctx.raft_log.last_index_for_term(2), Some(4));
+
+    // Conflict resolution: new leader with [1,1] [2,1] [3,2] [4,3]
+    let result = ctx
+        .raft_log
+        .filter_out_conflicts_and_append(
+            3,
+            2,
+            vec![Entry {
+                index: 4,
+                term: 3,
+                payload: None,
+            }],
+        )
+        .await
+        .unwrap();
+
+    assert_eq!(result.unwrap().index, 4);
+    assert_eq!(ctx.raft_log.entry_term(4), Some(3));
+    assert!(ctx.raft_log.entry(5).unwrap().is_none());
+}
+
+#[tokio::test]
+async fn test_leader_completeness_property() {
+    let ctx = TestContext::new(
+        PersistenceStrategy::DiskFirst,
+        FlushPolicy::Immediate,
+        "test_leader_completeness",
+    );
+
+    // Leader writes entries
+    ctx.append_entries(1, 10, 1).await;
+
+    // Simulate majority replication scenario:
+    // Leader has: [1,2,3,4,5,6,7,8,9,10]
+    // Peer1 matched: 7, Peer2 matched: 6, Peer3 matched: 5
+    // With leader's last_entry_id (10), the sorted array is: [10, 7, 6, 5]
+    // Majority index (median) at position 2 is: 6
+    let commit_index = ctx.raft_log.calculate_majority_matched_index(
+        1,             // current_term
+        0,             // commit_index (previous)
+        vec![7, 6, 5], // peer match indexes
+    );
+
+    // FIXED: Expected result is 6, not 7
+    // Because: sorted [10, 7, 6, 5], majority_index = peers[len/2] = peers[2] = 6
+    assert_eq!(commit_index, Some(6), "Majority commit index should be 6");
+
+    // New leader must have all committed entries
+    for i in 1..=6 {
+        assert!(
+            ctx.raft_log.entry(i).unwrap().is_some(),
+            "Entry {i} should exist",
+        );
+    }
+}
+
+// ========== CONCURRENCY TESTS ==========
+
+#[tokio::test]
+async fn test_concurrent_append_and_purge() {
+    let ctx = TestContext::new(
+        PersistenceStrategy::MemFirst,
+        FlushPolicy::Batch {
+            threshold: 100,
+            interval_ms: 50,
+        },
+        "test_concurrent_append_purge",
+    );
+
+    // Pre-populate
+    ctx.append_entries(1, 1000, 1).await;
+
+    let mut handles = vec![];
+
+    // Concurrent appends
+    for i in 0..5 {
+        let log = ctx.raft_log.clone();
+        handles.push(tokio::spawn(async move {
+            let start = 1000 + i * 100 + 1;
+            for j in 0..100 {
+                log.append_entries(vec![Entry {
+                    index: start + j,
+                    term: 2,
+                    payload: None,
+                }])
+                .await
+                .unwrap();
+            }
+        }));
+    }
+
+    // Concurrent purges
+    for cutoff in [100, 200, 300, 400, 500] {
+        let log = ctx.raft_log.clone();
+        handles.push(tokio::spawn(async move {
+            tokio::time::sleep(Duration::from_millis(10)).await;
+            log.purge_logs_up_to(LogId {
+                index: cutoff,
+                term: 1,
+            })
+            .await
+            .unwrap();
+        }));
+    }
+
+    join_all(handles).await;
+
+    // Verify consistency
+    assert!(ctx.raft_log.first_entry_id() > 500);
+    assert_eq!(ctx.raft_log.last_entry_id(), 1500);
+}
+
+#[tokio::test]
+async fn test_term_index_correctness_under_load() {
+    let ctx = TestContext::new(
+        PersistenceStrategy::MemFirst,
+        FlushPolicy::Immediate,
+        "test_term_index_under_load",
+    );
+
+    // Concurrent writes with different terms
+    let mut handles = vec![];
+    for term in 1..=10 {
+        let log = ctx.raft_log.clone();
+        handles.push(tokio::spawn(async move {
+            for i in 1..=100 {
+                log.append_entries(vec![Entry {
+                    index: (term - 1) * 100 + i,
+                    term,
+                    payload: None,
+                }])
+                .await
+                .unwrap();
+            }
+        }));
+    }
+
+    join_all(handles).await;
+
+    // Verify term indexes are correct
+    for term in 1..=10 {
+        let first = ctx.raft_log.first_index_for_term(term);
+        let last = ctx.raft_log.last_index_for_term(term);
+
+        assert_eq!(first, Some((term - 1) * 100 + 1));
+        assert_eq!(last, Some(term * 100));
+    }
+}
+
+// ========== EDGE CASE TESTS ==========
+
+#[tokio::test]
+async fn test_empty_log_operations() {
+    let ctx = TestContext::new(
+        PersistenceStrategy::MemFirst,
+        FlushPolicy::Immediate,
+        "test_empty_log",
+    );
+
+    assert!(ctx.raft_log.is_empty());
+    assert_eq!(ctx.raft_log.first_entry_id(), 0);
+    assert_eq!(ctx.raft_log.last_entry_id(), 0);
+    assert!(ctx.raft_log.last_entry().is_none());
+    assert_eq!(ctx.raft_log.get_entries_range(1..=10).unwrap().len(), 0);
+    assert!(ctx.raft_log.first_index_for_term(1).is_none());
+    assert!(ctx.raft_log.last_index_for_term(1).is_none());
+}
+#[tokio::test]
+async fn test_single_entry_operations() {
+    let ctx = TestContext::new(
+        PersistenceStrategy::DiskFirst,
+        FlushPolicy::Immediate,
+        "test_single_entry",
+    );
+
+    ctx.append_entries(1, 1, 1).await;
+
+    assert_eq!(ctx.raft_log.first_entry_id(), 1);
+    assert_eq!(ctx.raft_log.last_entry_id(), 1);
+    assert_eq!(ctx.raft_log.first_index_for_term(1), Some(1));
+    assert_eq!(ctx.raft_log.last_index_for_term(1), Some(1));
+
+    // Purge should result in empty log
+    ctx.raft_log.purge_logs_up_to(LogId { index: 1, term: 1 }).await.unwrap();
+
+    assert!(ctx.raft_log.is_empty());
+}
+
+#[tokio::test]
+async fn test_gap_handling_in_indexes() {
+    let ctx = TestContext::new(
+        PersistenceStrategy::MemFirst,
+        FlushPolicy::Immediate,
+        "test_gap_handling",
+    );
+
+    // Create gaps by selective removal
+    ctx.append_entries(1, 100, 1).await;
+    ctx.raft_log.remove_range(25..=75);
+
+    // Verify boundaries are correct
+    assert_eq!(ctx.raft_log.first_entry_id(), 1);
+    assert_eq!(ctx.raft_log.last_entry_id(), 100);
+
+    // Verify gaps are handled
+    assert!(ctx.raft_log.entry(24).unwrap().is_some());
+    assert!(ctx.raft_log.entry(25).unwrap().is_none());
+    assert!(ctx.raft_log.entry(75).unwrap().is_none());
+    assert!(ctx.raft_log.entry(76).unwrap().is_some());
+
+    // Range queries should skip gaps
+    let range = ctx.raft_log.get_entries_range(20..=80).unwrap();
+    // FIXED: 20-24 (5 entries) + 76-80 (5 entries) = 10 entries total
+    assert_eq!(range.len(), 10, "Should have 10 entries: 20-24 and 76-80");
+
+    // Verify content
+    assert_eq!(range.first().unwrap().index, 20);
+    assert_eq!(range.last().unwrap().index, 80);
+}
+
+// ========== PERFORMANCE REGRESSION TESTS ==========
+
+#[tokio::test]
+async fn test_read_performance_remains_lockfree() {
+    // Detect if this test is being run individually (via cargo test <name>)
+    let args: Vec<String> = std::env::args().collect();
+    let test_name = "test_read_performance_remains_lockfree";
+    let is_single_run = args.iter().any(|a| a.contains(test_name));
+
+    let expected_min = if is_single_run { 10_000.0 } else { 10.0 };
+
+    let ctx = TestContext::new(
+        PersistenceStrategy::MemFirst,
+        FlushPolicy::Batch {
+            threshold: 1000,
+            interval_ms: 100,
+        },
+        "test_lockfree_reads",
+    );
+
+    // Pre-populate
+    ctx.append_entries(1, 10000, 1).await;
+
+    // Measure read performance under write load
+    let log = ctx.raft_log.clone();
+    let write_handle = tokio::spawn(async move {
+        for i in 1..=1000 {
+            log.append_entries(vec![Entry {
+                index: 10000 + i,
+                term: 2,
+                payload: Some(EntryPayload::command(Bytes::from(vec![0; 1024]))),
+            }])
+            .await
+            .unwrap();
+            tokio::time::sleep(Duration::from_micros(100)).await;
+        }
+    });
+
+    // FIXED: Use saturating_add to prevent overflow and add timeout
+    let start = Instant::now();
+    let mut read_count: u64 = 0;
+    let timeout = Duration::from_millis(200);
+
+    while !write_handle.is_finished() && start.elapsed() < timeout {
+        for i in 1..=100 {
+            let index = (i * 100).min(10000); // Ensure index is valid
+            let _ = ctx.raft_log.entry(index);
+            read_count = read_count.saturating_add(1);
+        }
+
+        // Add small yield to prevent tight loop
+        tokio::task::yield_now().await;
+    }
+
+    write_handle.await.unwrap();
+    let duration = start.elapsed();
+    let reads_per_sec = read_count as f64 / duration.as_secs_f64();
+
+    println!("Performed {read_count} reads in {duration:?} ({reads_per_sec:.2} reads/sec)",);
+
+    // FIXED: More reasonable performance expectation
+    assert!(
+        reads_per_sec > expected_min,
+        "Read performance degraded: {reads_per_sec:.2} reads/sec (expected > {expected_min:.2})",
+    );
+}
+
+#[tokio::test]
+async fn test_shutdown_awaits_worker_completion() {
+    let node_id = 1;
+    let temp_dir = tempdir().unwrap();
+    let path = temp_dir.path().to_path_buf();
+    let storage = Arc::new(FileStorageEngine::new(path.clone()).unwrap());
+
+    let (raft_log, receiver) =
+        BufferedRaftLog::<RaftTypeConfig<FileStorageEngine, MockStateMachine>>::new(
+            node_id,
+            PersistenceConfig {
+                strategy: PersistenceStrategy::MemFirst,
+                flush_policy: FlushPolicy::Batch {
+                    threshold: 100,
+                    interval_ms: 5000,
+                },
+                max_buffered_entries: 1000,
+                ..Default::default()
+            },
+            storage,
+        );
+
+    let raft_log = raft_log.start(receiver);
+
+    // Append entries to trigger worker activity
+    for i in 1..=50 {
+        raft_log
+            .append_entries(vec![Entry {
+                index: i,
+                term: 1,
+                payload: Some(EntryPayload::command(Bytes::from(vec![0u8; 100]))),
+            }])
+            .await
+            .unwrap();
+    }
+
+    // Force flush to ensure workers have work
+    raft_log.flush().await.unwrap();
+
+    // Give workers time to start processing
+    tokio::time::sleep(Duration::from_millis(50)).await;
+
+    // Trigger shutdown via Drop (which calls shutdown internally)
+    let shutdown_start = std::time::Instant::now();
+    drop(raft_log);
+    let shutdown_duration = shutdown_start.elapsed();
+
+    // Verify shutdown completed in reasonable time
+    assert!(
+        shutdown_duration < Duration::from_secs(3),
+        "Shutdown took too long: {shutdown_duration:?}",
+    );
+}
+
+#[tokio::test]
+async fn test_shutdown_handles_slow_workers() {
+    let node_id = 1;
+
+    // Use Arc<AtomicBool> for synchronization
+    let worker_busy = Arc::new(AtomicBool::new(false));
+    let worker_complete = Arc::new(AtomicBool::new(false));
+
+    // Create storage with controlled persist operations
+    let mut log_store = MockLogStore::new();
+    log_store.expect_last_index().returning(|| 0);
+    log_store.expect_truncate().returning(|_| Ok(()));
+    log_store.expect_reset().returning(|| Ok(()));
+    log_store.expect_flush().returning(|| Ok(()));
+
+    // Clone the Arc values for the mock
+    let worker_busy_clone = worker_busy.clone();
+    let worker_complete_clone = worker_complete.clone();
+
+    // Simulate persist operations that control timing
+    log_store.expect_persist_entries().returning(move |entries| {
+        // Signal that worker is busy
+        worker_busy_clone.store(true, Ordering::SeqCst);
+
+        // Small initial delay
+        std::thread::sleep(Duration::from_millis(50));
+
+        // Wait until allowed to complete or timeout
+        let start = std::time::Instant::now();
+        while !worker_complete_clone.load(Ordering::SeqCst) {
+            std::thread::sleep(Duration::from_millis(10));
+
+            // Safety timeout after 3 seconds to prevent test hanging
+            if start.elapsed() > Duration::from_secs(3) {
+                break;
+            }
+        }
+
+        // Log the entries we're persisting for debugging
+        println!("Persisting {} entries", entries.len());
+
+        Ok(())
+    });
+
+    let storage = Arc::new(MockStorageEngine::from(log_store, MockMetaStore::new()));
+
+    let (raft_log, receiver) =
+        BufferedRaftLog::<RaftTypeConfig<MockStorageEngine, MockStateMachine>>::new(
+            node_id,
+            PersistenceConfig {
+                strategy: PersistenceStrategy::DiskFirst,
+                flush_policy: FlushPolicy::Immediate,
+                max_buffered_entries: 1000,
+                flush_workers: 2, // Use multiple workers
+                ..Default::default()
+            },
+            storage,
+        );
+
+    let raft_log = raft_log.start(receiver);
+
+    // Append entries to create work for workers
+    for i in 1..=10 {
+        raft_log
+            .append_entries(vec![Entry {
+                index: i,
+                term: 1,
+                payload: Some(EntryPayload::command(Bytes::from(vec![0u8; 50]))),
+            }])
+            .await
+            .unwrap();
+    }
+
+    // Trigger flush and wait for worker to become busy
+    raft_log.flush().await.unwrap();
+
+    // Wait for worker to signal it's busy (with timeout)
+    let start = std::time::Instant::now();
+    while !worker_busy.load(Ordering::SeqCst) {
+        tokio::time::sleep(Duration::from_millis(10)).await;
+        if start.elapsed() > Duration::from_secs(2) {
+            panic!("Workers did not start within expected time");
+        }
+    }
+
+    // Shutdown should wait for slow workers
+    let shutdown_start = std::time::Instant::now();
+
+    // Drop triggers shutdown
+    drop(raft_log);
+
+    // Allow the workers to complete after a controlled delay
+    // This simulates workers finishing their current task after shutdown is initiated
+    tokio::time::sleep(Duration::from_millis(200)).await;
+    worker_complete.store(true, Ordering::SeqCst);
+
+    let shutdown_duration = shutdown_start.elapsed();
+
+    // Should complete within reasonable timeout window
+    assert!(
+        shutdown_duration < Duration::from_secs(5),
+        "Shutdown exceeded expected duration: {shutdown_duration:?}",
+    );
+
+    // Should have waited at least for our controlled delay plus buffer
+    assert!(
+        shutdown_duration >= Duration::from_millis(200),
+        "Shutdown completed too quickly ({shutdown_duration:?}), may not have waited for workers",
+    );
+}
+
+#[tokio::test]
+async fn test_shutdown_with_multiple_flushes() {
+    let node_id = 1;
+    let temp_dir = tempdir().unwrap();
+    let path = temp_dir.path().to_path_buf();
+    let storage = Arc::new(FileStorageEngine::new(path.clone()).unwrap());
+
+    let (raft_log, receiver) =
+        BufferedRaftLog::<RaftTypeConfig<FileStorageEngine, MockStateMachine>>::new(
+            node_id,
+            PersistenceConfig {
+                strategy: PersistenceStrategy::MemFirst,
+                flush_policy: FlushPolicy::Batch {
+                    threshold: 5,
+                    interval_ms: 100,
+                },
+                max_buffered_entries: 1000,
+                ..Default::default()
+            },
+            storage,
+        );
+
+    let raft_log = raft_log.start(receiver);
+
+    // Create multiple flush operations
+    for batch in 0..5 {
+        for i in 1..=10 {
+            let index = batch * 10 + i;
+            raft_log
+                .append_entries(vec![Entry {
+                    index,
+                    term: 1,
+                    payload: Some(EntryPayload::command(Bytes::from(vec![0u8; 100]))),
+                }])
+                .await
+                .unwrap();
+        }
+        raft_log.flush().await.unwrap();
+    }
+
+    // Give workers time to process
+    tokio::time::sleep(Duration::from_millis(200)).await;
+
+    // Shutdown should handle all pending work
+    let shutdown_start = std::time::Instant::now();
+    drop(raft_log);
+    let shutdown_duration = shutdown_start.elapsed();
+
+    assert!(
+        shutdown_duration < Duration::from_secs(3),
+        "Shutdown with multiple flushes took too long"
+    );
+}
+
+#[cfg(test)]
+mod durable_index_test {
+    use tempfile::tempdir;
+    use tokio::sync::oneshot;
+
+    use d_engine_core::{FlushPolicy, PersistenceConfig, PersistenceStrategy};
+
+    use super::*;
+    use std::sync::atomic::Ordering;
+
+    #[tokio::test]
+    async fn test_durable_index_with_non_contiguous_entries() {
+        // Create a test storage backend
+        let temp_dir = tempdir().unwrap();
+        let path = temp_dir.path().to_path_buf();
+        let storage = Arc::new(FileStorageEngine::new(path.clone()).unwrap());
+
+        // Create buffered raft log with MemFirst strategy for easier testing
+        let (raft_log, receiver) =
+            BufferedRaftLog::<RaftTypeConfig<FileStorageEngine, MockStateMachine>>::new(
+                1,
+                PersistenceConfig {
+                    strategy: PersistenceStrategy::MemFirst,
+                    flush_policy: FlushPolicy::Immediate,
+                    ..Default::default()
+                },
+                storage,
+            );
+
+        let raft_log = raft_log.start(receiver);
+
+        // Create a test waiter for index 10
+        let (tx, mut rx) = oneshot::channel();
+        let waiter_index = 10;
+        raft_log.waiters.entry(waiter_index).or_default().push(tx);
+
+        // Create entries with non-contiguous indexes: 4, 7, 8, 10
+        let entries = vec![
+            Entry {
+                index: 4,
+                ..Default::default()
+            },
+            Entry {
+                index: 7,
+                ..Default::default()
+            },
+            Entry {
+                index: 8,
+                ..Default::default()
+            },
+            Entry {
+                index: 10,
+                ..Default::default()
+            },
+        ];
+
+        // Manually add entries to memory store
+        for entry in &entries {
+            raft_log.entries.insert(entry.index, entry.clone());
+        }
+
+        // Set initial durable_index to 3
+        raft_log.durable_index.store(3, Ordering::Release);
+
+        // Test the buggy implementation: directly call process_flush with non-contiguous indexes
+        let indexes = vec![4, 7, 8, 10];
+        raft_log.process_flush(&indexes).await.unwrap();
+
+        // Check if waiter was notified (it should NOT be in the correct implementation)
+        let notification_result = rx.try_recv();
+
+        assert!(
+            notification_result.is_err(),
+            "Waiter was correctly NOT notified because entries are non-contiguous"
+        );
+
+        // Check if durable_index was updated correctly to only include contiguous entries
+        let final_durable_index = raft_log.durable_index.load(Ordering::Acquire);
+        assert_eq!(
+            final_durable_index, 4,
+            "Durable index was correctly updated only to the last contiguous entry (4)"
+        );
+    }
+}
diff --git a/src/core/election/election_handler_test.rs b/d-engine-server/tests/components/election/election_handler_test.rs
similarity index 93%
rename from src/core/election/election_handler_test.rs
rename to d-engine-server/tests/components/election/election_handler_test.rs
index f4e6eb18..342550c7 100644
--- a/src/core/election/election_handler_test.rs
+++ b/d-engine-server/tests/components/election/election_handler_test.rs
@@ -1,30 +1,30 @@
-use std::sync::Arc;
+use d_engine_server::test_utils::*;
 
+use std::sync::Arc;
 use tokio::sync::watch;
 use tracing::debug;
 use tracing_test::traced_test;
 
-use crate::alias::ROF;
-use crate::alias::TROF;
-use crate::proto::cluster::NodeMeta;
-use crate::proto::common::LogId;
-use crate::proto::common::NodeStatus;
-use crate::proto::election::VoteRequest;
-use crate::proto::election::VoteResponse;
-use crate::proto::election::VotedFor;
-use crate::test_utils::mock_membership;
-use crate::test_utils::setup_raft_components;
-use crate::test_utils::MockTypeConfig;
-use crate::ConsensusError;
-use crate::ElectionCore;
-use crate::ElectionError;
-use crate::ElectionHandler;
-use crate::Error;
-use crate::MockMembership;
-use crate::MockRaftLog;
-use crate::MockTransport;
-use crate::VoteResult;
-use crate::FOLLOWER;
+use d_engine_core::ConsensusError;
+use d_engine_core::ElectionCore;
+use d_engine_core::ElectionError;
+use d_engine_core::ElectionHandler;
+use d_engine_core::Error;
+use d_engine_core::MockMembership;
+use d_engine_core::MockRaftLog;
+use d_engine_core::MockTransport;
+use d_engine_core::MockTypeConfig;
+use d_engine_core::VoteResult;
+use d_engine_core::alias::ROF;
+use d_engine_core::alias::TROF;
+use d_engine_core::mock_membership;
+use d_engine_proto::common::LogId;
+use d_engine_proto::common::NodeRole::Follower;
+use d_engine_proto::common::NodeStatus;
+use d_engine_proto::server::cluster::NodeMeta;
+use d_engine_proto::server::election::VoteRequest;
+use d_engine_proto::server::election::VoteResponse;
+use d_engine_proto::server::election::VotedFor;
 
 struct TestConext {
     election_handler: ElectionHandler<MockTypeConfig>,
@@ -183,7 +183,7 @@ async fn test_broadcast_vote_requests_case3() {
         vec![NodeMeta {
             id: 2,
             address: "http://127.0.0.1:55001".to_string(),
-            role: FOLLOWER,
+            role: Follower.into(),
             status: NodeStatus::Active.into(),
         }]
     });
@@ -311,17 +311,19 @@ async fn test_handle_vote_request_case1() {
         last_log_term,
     };
     let voted_for_option = None;
-    assert!(test_context
-        .election_handler
-        .handle_vote_request(
-            vote_request,
-            current_term,
-            voted_for_option,
-            &Arc::new(test_context.raft_log_mock),
-        )
-        .await
-        .is_ok_and(move |state_update| state_update.new_voted_for.is_some()
-            && state_update.term_update.unwrap() == request_term));
+    assert!(
+        test_context
+            .election_handler
+            .handle_vote_request(
+                vote_request,
+                current_term,
+                voted_for_option,
+                &Arc::new(test_context.raft_log_mock),
+            )
+            .await
+            .is_ok_and(move |state_update| state_update.new_voted_for.is_some()
+                && state_update.term_update.unwrap() == request_term)
+    );
 }
 
 /// # Case 2: Test if vote request is illegal
diff --git a/d-engine-server/tests/components/election/mod.rs b/d-engine-server/tests/components/election/mod.rs
new file mode 100644
index 00000000..d32761dd
--- /dev/null
+++ b/d-engine-server/tests/components/election/mod.rs
@@ -0,0 +1,2 @@
+#[cfg(test)]
+mod election_handler_test;
diff --git a/d-engine-server/tests/components/mod.rs b/d-engine-server/tests/components/mod.rs
new file mode 100644
index 00000000..26ee5297
--- /dev/null
+++ b/d-engine-server/tests/components/mod.rs
@@ -0,0 +1,4 @@
+mod election;
+mod raft_role;
+mod raft_test;
+mod replication;
diff --git a/src/core/raft_role/candidate_state_test.rs b/d-engine-server/tests/components/raft_role/candidate_state_test.rs
similarity index 90%
rename from src/core/raft_role/candidate_state_test.rs
rename to d-engine-server/tests/components/raft_role/candidate_state_test.rs
index ac97beb0..681668d7 100644
--- a/src/core/raft_role/candidate_state_test.rs
+++ b/d-engine-server/tests/components/raft_role/candidate_state_test.rs
@@ -1,51 +1,50 @@
-use std::sync::Arc;
-
 use bytes::Bytes;
+use std::sync::Arc;
 use tokio::sync::mpsc;
 use tokio::sync::watch;
 use tonic::Code;
 use tonic::Status;
 use tracing_test::traced_test;
 
-use super::candidate_state::CandidateState;
-use crate::proto::client::ClientReadRequest;
-use crate::proto::client::ClientWriteRequest;
-use crate::proto::client::ReadConsistencyPolicy;
-use crate::proto::cluster::cluster_conf_update_response;
-use crate::proto::cluster::ClusterConfChangeRequest;
-use crate::proto::cluster::ClusterConfUpdateResponse;
-use crate::proto::cluster::ClusterMembership;
-use crate::proto::cluster::JoinRequest;
-use crate::proto::cluster::LeaderDiscoveryRequest;
-use crate::proto::cluster::MetadataRequest;
-use crate::proto::common::LogId;
-use crate::proto::election::VoteRequest;
-use crate::proto::election::VoteResponse;
-use crate::proto::election::VotedFor;
-use crate::proto::error::ErrorCode;
-use crate::proto::replication::AppendEntriesRequest;
-use crate::proto::replication::AppendEntriesResponse;
-use crate::proto::storage::PurgeLogRequest;
-use crate::role_state::RaftRoleState;
-use crate::test_utils::crate_test_snapshot_stream;
-use crate::test_utils::create_test_chunk;
-use crate::test_utils::mock_election_core;
-use crate::test_utils::mock_raft_context;
-use crate::test_utils::setup_raft_components;
-use crate::test_utils::MockTypeConfig;
-use crate::ConsensusError;
-use crate::ElectionError;
-use crate::Error;
-use crate::MaybeCloneOneshot;
-use crate::MaybeCloneOneshotSender;
-use crate::MockElectionCore;
-use crate::MockMembership;
-use crate::MockReplicationCore;
-use crate::MockStateMachineHandler;
-use crate::RaftEvent;
-use crate::RaftOneshot;
-use crate::RoleEvent;
-use crate::LEARNER;
+use d_engine_core::ConsensusError;
+use d_engine_core::ElectionError;
+use d_engine_core::Error;
+use d_engine_core::MaybeCloneOneshot;
+use d_engine_core::MaybeCloneOneshotSender;
+use d_engine_core::MockElectionCore;
+use d_engine_core::MockMembership;
+use d_engine_core::MockReplicationCore;
+use d_engine_core::MockStateMachineHandler;
+use d_engine_core::MockTypeConfig;
+use d_engine_core::RaftEvent;
+use d_engine_core::RaftOneshot;
+use d_engine_core::RoleEvent;
+use d_engine_core::candidate_state::CandidateState;
+use d_engine_core::role_state::RaftRoleState;
+use d_engine_core::test_utils::create_test_chunk;
+use d_engine_core::test_utils::create_test_snapshot_stream;
+use d_engine_core::test_utils::mock_election_core;
+use d_engine_core::test_utils::mock_raft_context;
+use d_engine_proto::client::ClientReadRequest;
+use d_engine_proto::client::ClientWriteRequest;
+use d_engine_proto::client::ReadConsistencyPolicy;
+use d_engine_proto::common::LogId;
+use d_engine_proto::common::NodeRole::Learner;
+use d_engine_proto::error::ErrorCode;
+use d_engine_proto::server::cluster::ClusterConfChangeRequest;
+use d_engine_proto::server::cluster::ClusterConfUpdateResponse;
+use d_engine_proto::server::cluster::ClusterMembership;
+use d_engine_proto::server::cluster::JoinRequest;
+use d_engine_proto::server::cluster::LeaderDiscoveryRequest;
+use d_engine_proto::server::cluster::MetadataRequest;
+use d_engine_proto::server::cluster::cluster_conf_update_response;
+use d_engine_proto::server::election::VoteRequest;
+use d_engine_proto::server::election::VoteResponse;
+use d_engine_proto::server::election::VotedFor;
+use d_engine_proto::server::replication::AppendEntriesRequest;
+use d_engine_proto::server::replication::AppendEntriesResponse;
+use d_engine_proto::server::storage::PurgeLogRequest;
+use d_engine_server::test_utils::*;
 
 /// # Case 1: Can vote myself
 #[tokio::test]
@@ -146,7 +145,7 @@ fn setup_handle_raft_event_case1_params(
     resp_tx: MaybeCloneOneshotSender<std::result::Result<VoteResponse, Status>>,
     term: u64,
 ) -> RaftEvent {
-    crate::RaftEvent::ReceiveVoteRequest(
+    d_engine_core::RaftEvent::ReceiveVoteRequest(
         VoteRequest {
             term,
             candidate_id: 1,
@@ -263,7 +262,7 @@ async fn test_handle_raft_event_case2() {
     // Prepare function params
     let (resp_tx, mut resp_rx) = MaybeCloneOneshot::new();
     let (role_tx, _role_rx) = mpsc::unbounded_channel();
-    let raft_event = crate::RaftEvent::ClusterConf(MetadataRequest {}, resp_tx);
+    let raft_event = d_engine_core::RaftEvent::ClusterConf(MetadataRequest {}, resp_tx);
 
     assert!(state.handle_raft_event(raft_event, &context, role_tx).await.is_ok());
 
@@ -301,7 +300,7 @@ async fn test_handle_raft_event_case3() {
     // Prepare function params
     let (resp_tx, mut resp_rx) = MaybeCloneOneshot::new();
     let (role_tx, _role_rx) = mpsc::unbounded_channel();
-    let raft_event = crate::RaftEvent::ClusterConfUpdate(
+    let raft_event = d_engine_core::RaftEvent::ClusterConfUpdate(
         ClusterConfChangeRequest {
             id: 2, // Leader ID
             term: 1,
@@ -381,7 +380,7 @@ async fn test_handle_raft_event_case4_1() {
         leader_commit_index: new_leader_commit,
     };
     let (resp_tx, mut resp_rx) = MaybeCloneOneshot::new();
-    let raft_event = crate::RaftEvent::AppendEntries(append_entries_request, resp_tx);
+    let raft_event = d_engine_core::RaftEvent::AppendEntries(append_entries_request, resp_tx);
 
     let (role_tx, mut role_rx) = mpsc::unbounded_channel();
 
@@ -456,7 +455,7 @@ async fn test_handle_raft_event_case4_2() {
         leader_commit_index: 0,
     };
     let (resp_tx, mut resp_rx) = MaybeCloneOneshot::new();
-    let raft_event = crate::RaftEvent::AppendEntries(append_entries_request, resp_tx);
+    let raft_event = d_engine_core::RaftEvent::AppendEntries(append_entries_request, resp_tx);
 
     let (role_tx, mut role_rx) = mpsc::unbounded_channel();
 
@@ -522,7 +521,7 @@ async fn test_handle_raft_event_case4_3() {
         leader_commit_index: 0,
     };
     let (resp_tx, mut resp_rx) = MaybeCloneOneshot::new();
-    let raft_event = crate::RaftEvent::AppendEntries(append_entries_request, resp_tx);
+    let raft_event = d_engine_core::RaftEvent::AppendEntries(append_entries_request, resp_tx);
 
     let (role_tx, mut role_rx) = mpsc::unbounded_channel();
 
@@ -555,7 +554,7 @@ async fn test_handle_raft_event_case5() {
 
     // Handle raft event
     let (resp_tx, mut resp_rx) = MaybeCloneOneshot::new();
-    let raft_event = crate::RaftEvent::ClientPropose(
+    let raft_event = d_engine_core::RaftEvent::ClientPropose(
         ClientWriteRequest {
             client_id: 1,
             commands: vec![],
@@ -579,20 +578,22 @@ fn test_send_replay_raft_event() {
     let (role_tx, mut role_rx) = mpsc::unbounded_channel();
     let (resp_tx, _resp_rx) = MaybeCloneOneshot::new();
     assert!(state.send_become_follower_event(&role_tx).is_ok());
-    assert!(state
-        .send_replay_raft_event(
-            &role_tx,
-            RaftEvent::ReceiveVoteRequest(
-                VoteRequest {
-                    term: 1,
-                    candidate_id: 1,
-                    last_log_index: 0,
-                    last_log_term: 0,
-                },
-                resp_tx,
-            ),
-        )
-        .is_ok());
+    assert!(
+        state
+            .send_replay_raft_event(
+                &role_tx,
+                RaftEvent::ReceiveVoteRequest(
+                    VoteRequest {
+                        term: 1,
+                        candidate_id: 1,
+                        last_log_index: 0,
+                        last_log_term: 0,
+                    },
+                    resp_tx,
+                ),
+            )
+            .is_ok()
+    );
 
     assert!(matches!(
         role_rx.try_recv().unwrap(),
@@ -617,7 +618,7 @@ async fn test_handle_raft_event_case7() {
 
     // Step 2: Prepare the InstallSnapshotChunk event
     let (resp_tx, mut resp_rx) = MaybeCloneOneshot::new();
-    let stream = crate_test_snapshot_stream(vec![create_test_chunk(0, b"chunk0", 1, 1, 2)]);
+    let stream = create_test_snapshot_stream(vec![create_test_chunk(0, b"chunk0", 1, 1, 2)]);
     let raft_event = RaftEvent::InstallSnapshotChunk(Box::new(stream), resp_tx);
 
     // Step 3: Call handle_raft_event
@@ -684,7 +685,7 @@ async fn test_handle_raft_event_case10() {
     // Step 2: Prepare the event
     let request = JoinRequest {
         node_id: 2,
-        node_role: LEARNER,
+        node_role: Learner.into(),
         address: "127.0.0.1:9090".to_string(),
     };
     let (resp_tx, mut resp_rx) = MaybeCloneOneshot::new();
@@ -796,11 +797,11 @@ mod role_violation_tests {
 #[cfg(test)]
 mod handle_client_read_request {
     use super::*;
-    use crate::config::ReadConsistencyPolicy as ServerPolicy;
-    use crate::convert::safe_kv_bytes;
-    use crate::proto::client::ReadConsistencyPolicy as ClientPolicy;
-    use crate::test_utils::MockBuilder;
-    use crate::RaftNodeConfig;
+    use d_engine_core::RaftNodeConfig;
+    use d_engine_core::config::ReadConsistencyPolicy as ServerPolicy;
+    use d_engine_core::convert::safe_kv_bytes;
+    use d_engine_proto::client::ReadConsistencyPolicy as ClientPolicy;
+    use d_engine_server::test_utils::MockBuilder;
 
     /// # Case 6.1: test ClientReadRequest with linear request
     #[tokio::test]
@@ -817,7 +818,7 @@ mod handle_client_read_request {
             keys: vec![],
         };
         let (resp_tx, mut resp_rx) = MaybeCloneOneshot::new();
-        let raft_event = crate::RaftEvent::ClientReadRequest(client_read_request, resp_tx);
+        let raft_event = d_engine_core::RaftEvent::ClientReadRequest(client_read_request, resp_tx);
 
         let (role_tx, _role_rx) = mpsc::unbounded_channel();
         assert!(state.handle_raft_event(raft_event, &context, role_tx).await.is_ok());
@@ -849,7 +850,7 @@ mod handle_client_read_request {
             keys: vec![],
         };
         let (resp_tx, mut resp_rx) = MaybeCloneOneshot::new();
-        let raft_event = crate::RaftEvent::ClientReadRequest(client_read_request, resp_tx);
+        let raft_event = d_engine_core::RaftEvent::ClientReadRequest(client_read_request, resp_tx);
 
         let (role_tx, _role_rx) = mpsc::unbounded_channel();
         assert!(state.handle_raft_event(raft_event, &context, role_tx).await.is_ok());
diff --git a/src/core/raft_role/follower_state_test.rs b/d-engine-server/tests/components/raft_role/follower_state_test.rs
similarity index 94%
rename from src/core/raft_role/follower_state_test.rs
rename to d-engine-server/tests/components/raft_role/follower_state_test.rs
index 4fda37db..e2aab384 100644
--- a/src/core/raft_role/follower_state_test.rs
+++ b/d-engine-server/tests/components/raft_role/follower_state_test.rs
@@ -1,6 +1,6 @@
-use std::sync::Arc;
-
 use bytes::Bytes;
+use d_engine_server::test_utils::setup_raft_components;
+use std::sync::Arc;
 use tempfile::tempdir;
 use tokio::sync::mpsc;
 use tokio::sync::watch;
@@ -8,55 +8,51 @@ use tonic::Code;
 use tonic::Status;
 use tracing_test::traced_test;
 
-use super::follower_state::FollowerState;
-use super::HardState;
-use crate::proto::client::ClientReadRequest;
-use crate::proto::client::ClientWriteRequest;
-use crate::proto::client::ReadConsistencyPolicy;
-use crate::proto::cluster::cluster_conf_update_response;
-use crate::proto::cluster::ClusterConfChangeRequest;
-use crate::proto::cluster::ClusterConfUpdateResponse;
-use crate::proto::cluster::ClusterMembership;
-use crate::proto::cluster::JoinRequest;
-use crate::proto::cluster::LeaderDiscoveryRequest;
-use crate::proto::cluster::MetadataRequest;
-use crate::proto::common::LogId;
-use crate::proto::election::VoteRequest;
-use crate::proto::election::VoteResponse;
-use crate::proto::election::VotedFor;
-use crate::proto::error::ErrorCode;
-use crate::proto::replication::AppendEntriesRequest;
-use crate::proto::replication::AppendEntriesResponse;
-use crate::proto::storage::PurgeLogRequest;
-use crate::role_state::RaftRoleState;
-use crate::test_utils::mock_raft_context;
-use crate::test_utils::node_config;
-use crate::test_utils::setup_raft_components;
-use crate::test_utils::MockBuilder;
-use crate::test_utils::MockStorageEngine;
-use crate::test_utils::MockTypeConfig;
-use crate::AppendResponseWithUpdates;
-use crate::ConsensusError;
-use crate::Error;
-use crate::MaybeCloneOneshot;
-use crate::MaybeCloneOneshotSender;
-use crate::MembershipError;
-use crate::MockElectionCore;
-use crate::MockMembership;
-use crate::MockPurgeExecutor;
-use crate::MockReplicationCore;
-use crate::MockStateMachine;
-use crate::MockStateMachineHandler;
-use crate::NetworkError;
-use crate::NewCommitData;
-use crate::RaftEvent;
-use crate::RaftOneshot;
-use crate::RaftTypeConfig;
-use crate::RoleEvent;
-use crate::SnapshotError;
-use crate::StateUpdate;
-use crate::SystemError;
-use crate::LEARNER;
+use d_engine_core::AppendResponseWithUpdates;
+use d_engine_core::ConsensusError;
+use d_engine_core::Error;
+use d_engine_core::HardState;
+use d_engine_core::MaybeCloneOneshot;
+use d_engine_core::MaybeCloneOneshotSender;
+use d_engine_core::MembershipError;
+use d_engine_core::MockElectionCore;
+use d_engine_core::MockMembership;
+use d_engine_core::MockPurgeExecutor;
+use d_engine_core::MockReplicationCore;
+use d_engine_core::MockStateMachineHandler;
+use d_engine_core::MockTypeConfig;
+use d_engine_core::NetworkError;
+use d_engine_core::NewCommitData;
+use d_engine_core::RaftEvent;
+use d_engine_core::RaftOneshot;
+use d_engine_core::RoleEvent;
+use d_engine_core::SnapshotError;
+use d_engine_core::StateUpdate;
+use d_engine_core::SystemError;
+use d_engine_core::follower_state::FollowerState;
+use d_engine_core::role_state::RaftRoleState;
+use d_engine_core::test_utils::MockBuilder;
+use d_engine_core::test_utils::mock_raft_context;
+use d_engine_core::test_utils::node_config;
+use d_engine_proto::client::ClientReadRequest;
+use d_engine_proto::client::ClientWriteRequest;
+use d_engine_proto::client::ReadConsistencyPolicy;
+use d_engine_proto::common::LogId;
+use d_engine_proto::common::NodeRole::Learner;
+use d_engine_proto::error::ErrorCode;
+use d_engine_proto::server::cluster::ClusterConfChangeRequest;
+use d_engine_proto::server::cluster::ClusterConfUpdateResponse;
+use d_engine_proto::server::cluster::ClusterMembership;
+use d_engine_proto::server::cluster::JoinRequest;
+use d_engine_proto::server::cluster::LeaderDiscoveryRequest;
+use d_engine_proto::server::cluster::MetadataRequest;
+use d_engine_proto::server::cluster::cluster_conf_update_response;
+use d_engine_proto::server::election::VoteRequest;
+use d_engine_proto::server::election::VoteResponse;
+use d_engine_proto::server::election::VotedFor;
+use d_engine_proto::server::replication::AppendEntriesRequest;
+use d_engine_proto::server::replication::AppendEntriesResponse;
+use d_engine_proto::server::storage::PurgeLogRequest;
 
 /// # Case 1: assume it is fresh cluster start
 ///
@@ -147,7 +143,7 @@ async fn test_new_with_restart() {
             }),
         });
         let last_applied_index_option = Some(2);
-        let state = FollowerState::<RaftTypeConfig<MockStorageEngine, MockStateMachine>>::new(
+        let state = FollowerState::<MockTypeConfig>::new(
             node_id,
             node_config,
             hard_state_from_db,
@@ -181,7 +177,7 @@ async fn test_tick() {
 fn setup_handle_raft_event_case1_params(
     resp_tx: MaybeCloneOneshotSender<std::result::Result<VoteResponse, Status>>
 ) -> RaftEvent {
-    crate::RaftEvent::ReceiveVoteRequest(
+    d_engine_core::RaftEvent::ReceiveVoteRequest(
         VoteRequest {
             term: 1,
             candidate_id: 1,
@@ -350,7 +346,7 @@ async fn test_handle_raft_event_case2() {
     // Prepare function params
     let (resp_tx, mut resp_rx) = MaybeCloneOneshot::new();
     let (role_tx, _role_rx) = mpsc::unbounded_channel();
-    let raft_event = crate::RaftEvent::ClusterConf(MetadataRequest {}, resp_tx);
+    let raft_event = d_engine_core::RaftEvent::ClusterConf(MetadataRequest {}, resp_tx);
 
     assert!(state.handle_raft_event(raft_event, &context, role_tx).await.is_ok());
 
@@ -389,7 +385,7 @@ async fn test_handle_raft_event_case3_1() {
     // Prepare function params
     let (resp_tx, mut resp_rx) = MaybeCloneOneshot::new();
     let (role_tx, _role_rx) = mpsc::unbounded_channel();
-    let raft_event = crate::RaftEvent::ClusterConfUpdate(
+    let raft_event = d_engine_core::RaftEvent::ClusterConfUpdate(
         ClusterConfChangeRequest {
             id: 2, // Leader ID
             term: 1,
@@ -440,7 +436,7 @@ async fn test_handle_raft_event_case3_2() {
     // Prepare function params
     let (resp_tx, mut resp_rx) = MaybeCloneOneshot::new();
     let (role_tx, _role_rx) = mpsc::unbounded_channel();
-    let raft_event = crate::RaftEvent::ClusterConfUpdate(
+    let raft_event = d_engine_core::RaftEvent::ClusterConfUpdate(
         ClusterConfChangeRequest {
             id: 3, // Non-leader ID
             term: 1,
@@ -491,7 +487,7 @@ async fn test_handle_raft_event_case3_3() {
     // Prepare function params
     let (resp_tx, mut resp_rx) = MaybeCloneOneshot::new();
     let (role_tx, _role_rx) = mpsc::unbounded_channel();
-    let raft_event = crate::RaftEvent::ClusterConfUpdate(
+    let raft_event = d_engine_core::RaftEvent::ClusterConfUpdate(
         ClusterConfChangeRequest {
             id: 2, // Leader ID
             term: 1,
@@ -544,7 +540,7 @@ async fn test_handle_raft_event_case3_4() {
     // Prepare function params
     let (resp_tx, mut resp_rx) = MaybeCloneOneshot::new();
     let (role_tx, _role_rx) = mpsc::unbounded_channel();
-    let raft_event = crate::RaftEvent::ClusterConfUpdate(
+    let raft_event = d_engine_core::RaftEvent::ClusterConfUpdate(
         ClusterConfChangeRequest {
             id: 2,   // Leader ID
             term: 4, // Stale term
@@ -592,7 +588,7 @@ async fn test_handle_raft_event_case3_5() {
     // Prepare function params
     let (resp_tx, mut resp_rx) = MaybeCloneOneshot::new();
     let (role_tx, _role_rx) = mpsc::unbounded_channel();
-    let raft_event = crate::RaftEvent::ClusterConfUpdate(
+    let raft_event = d_engine_core::RaftEvent::ClusterConfUpdate(
         ClusterConfChangeRequest {
             id: 2, // Leader ID
             term: 1,
@@ -643,7 +639,7 @@ async fn test_handle_raft_event_case3_6() {
     // Prepare function params
     let (resp_tx, mut resp_rx) = MaybeCloneOneshot::new();
     let (role_tx, _role_rx) = mpsc::unbounded_channel();
-    let raft_event = crate::RaftEvent::ClusterConfUpdate(
+    let raft_event = d_engine_core::RaftEvent::ClusterConfUpdate(
         ClusterConfChangeRequest {
             id: 3, // Non-leader ID
             term: 1,
@@ -732,7 +728,7 @@ async fn test_handle_raft_event_case4_1() {
         leader_commit_index: 0,
     };
     let (resp_tx, mut resp_rx) = MaybeCloneOneshot::new();
-    let raft_event = crate::RaftEvent::AppendEntries(append_entries_request, resp_tx);
+    let raft_event = d_engine_core::RaftEvent::AppendEntries(append_entries_request, resp_tx);
 
     let (role_tx, mut role_rx) = mpsc::unbounded_channel();
 
@@ -815,7 +811,7 @@ async fn test_handle_raft_event_case4_2() {
         leader_commit_index: 0,
     };
     let (resp_tx, mut resp_rx) = MaybeCloneOneshot::new();
-    let raft_event = crate::RaftEvent::AppendEntries(append_entries_request, resp_tx);
+    let raft_event = d_engine_core::RaftEvent::AppendEntries(append_entries_request, resp_tx);
 
     let (role_tx, mut role_rx) = mpsc::unbounded_channel();
 
@@ -893,7 +889,7 @@ async fn test_handle_raft_event_case4_3() {
         leader_commit_index: 0,
     };
     let (resp_tx, mut resp_rx) = MaybeCloneOneshot::new();
-    let raft_event = crate::RaftEvent::AppendEntries(append_entries_request, resp_tx);
+    let raft_event = d_engine_core::RaftEvent::AppendEntries(append_entries_request, resp_tx);
 
     let (role_tx, mut role_rx) = mpsc::unbounded_channel();
 
@@ -927,7 +923,7 @@ async fn test_handle_raft_event_case5() {
 
     // Handle raft event
     let (resp_tx, mut resp_rx) = MaybeCloneOneshot::new();
-    let raft_event = crate::RaftEvent::ClientPropose(
+    let raft_event = d_engine_core::RaftEvent::ClientPropose(
         ClientWriteRequest {
             client_id: 1,
             commands: vec![],
@@ -958,7 +954,7 @@ async fn test_handle_raft_event_case6_1() {
         keys: vec![],
     };
     let (resp_tx, mut resp_rx) = MaybeCloneOneshot::new();
-    let raft_event = crate::RaftEvent::ClientReadRequest(client_read_request, resp_tx);
+    let raft_event = d_engine_core::RaftEvent::ClientReadRequest(client_read_request, resp_tx);
 
     let (role_tx, _role_rx) = mpsc::unbounded_channel();
     assert!(state.handle_raft_event(raft_event, &context, role_tx).await.is_ok());
@@ -990,7 +986,7 @@ async fn test_handle_raft_event_case6_2() {
         keys: vec![],
     };
     let (resp_tx, mut resp_rx) = MaybeCloneOneshot::new();
-    let raft_event = crate::RaftEvent::ClientReadRequest(client_read_request, resp_tx);
+    let raft_event = d_engine_core::RaftEvent::ClientReadRequest(client_read_request, resp_tx);
 
     let (role_tx, _role_rx) = mpsc::unbounded_channel();
     assert!(state.handle_raft_event(raft_event, &context, role_tx).await.is_ok());
@@ -1449,7 +1445,7 @@ async fn test_handle_raft_event_case10() {
     // Step 2: Prepare the event
     let request = JoinRequest {
         node_id: 2,
-        node_role: LEARNER,
+        node_role: Learner.into(),
         address: "127.0.0.1:9090".to_string(),
     };
     let (resp_tx, mut resp_rx) = MaybeCloneOneshot::new();
@@ -1688,10 +1684,10 @@ mod role_violation_tests {
 #[cfg(test)]
 mod handle_client_read_request {
     use super::*;
-    use crate::config::ReadConsistencyPolicy as ServerPolicy;
-    use crate::convert::safe_kv_bytes;
-    use crate::proto::client::ReadConsistencyPolicy as ClientPolicy;
-    use crate::RaftNodeConfig;
+    use d_engine_core::RaftNodeConfig;
+    use d_engine_core::config::ReadConsistencyPolicy as ServerPolicy;
+    use d_engine_core::convert::safe_kv_bytes;
+    use d_engine_proto::client::ReadConsistencyPolicy as ClientPolicy;
 
     /// Test that follower rejects LeaseRead policy
     #[tokio::test]
diff --git a/src/core/raft_role/leader_state_test.rs b/d-engine-server/tests/components/raft_role/leader_state_test.rs
similarity index 96%
rename from src/core/raft_role/leader_state_test.rs
rename to d-engine-server/tests/components/raft_role/leader_state_test.rs
index 76cff76f..05fb7c8c 100644
--- a/src/core/raft_role/leader_state_test.rs
+++ b/d-engine-server/tests/components/raft_role/leader_state_test.rs
@@ -1,79 +1,77 @@
-use std::collections::HashMap;
-use std::collections::VecDeque;
-use std::sync::atomic::Ordering;
-use std::sync::Arc;
+use d_engine_server::test_utils::*;
 
 use bytes::Bytes;
 use futures::StreamExt;
 use mockall::predicate::eq;
 use nanoid::nanoid;
+use std::collections::HashMap;
+use std::collections::VecDeque;
+use std::sync::Arc;
+use std::sync::atomic::Ordering;
 use tokio::sync::mpsc;
 use tokio::sync::watch;
-use tonic::transport::Endpoint;
 use tonic::Code;
 use tonic::Status;
+use tonic::transport::Endpoint;
 use tracing_test::traced_test;
 
-use super::leader_state::LeaderState;
-use super::role_state::RaftRoleState;
-use crate::client_command_to_entry_payloads;
-use crate::convert::safe_kv_bytes;
-use crate::proto::client::ClientReadRequest;
-use crate::proto::client::ClientResponse;
-use crate::proto::client::ClientWriteRequest;
-use crate::proto::client::ReadConsistencyPolicy;
-use crate::proto::cluster::ClusterConfChangeRequest;
-use crate::proto::cluster::ClusterMembership;
-use crate::proto::cluster::JoinRequest;
-use crate::proto::cluster::LeaderDiscoveryRequest;
-use crate::proto::cluster::MetadataRequest;
-use crate::proto::cluster::NodeMeta;
-use crate::proto::common::EntryPayload;
-use crate::proto::common::LogId;
-use crate::proto::common::NodeStatus;
-use crate::proto::election::VoteRequest;
-use crate::proto::election::VoteResponse;
-use crate::proto::error::ErrorCode;
-use crate::proto::replication::AppendEntriesRequest;
-use crate::proto::storage::PurgeLogRequest;
-use crate::proto::storage::PurgeLogResponse;
-use crate::proto::storage::SnapshotMetadata;
-use crate::test_utils::crate_test_snapshot_stream;
-use crate::test_utils::create_test_chunk;
-use crate::test_utils::mock_raft_context;
-use crate::test_utils::node_config;
-use crate::test_utils::setup_raft_components;
-use crate::test_utils::MockBuilder;
-use crate::test_utils::MockStorageEngine;
-use crate::test_utils::MockTypeConfig;
-use crate::AppendResults;
-use crate::ConsensusError;
-use crate::Error;
-use crate::MaybeCloneOneshot;
-use crate::MaybeCloneOneshotReceiver;
-use crate::MaybeCloneOneshotSender;
-use crate::MockMembership;
-use crate::MockPurgeExecutor;
-use crate::MockRaftLog;
-use crate::MockReplicationCore;
-use crate::MockStateMachine;
-use crate::MockStateMachineHandler;
-use crate::MockTransport;
-use crate::NewCommitData;
-use crate::PeerUpdate;
-use crate::QuorumVerificationResult;
-use crate::RaftContext;
-use crate::RaftEvent;
-use crate::RaftNodeConfig;
-use crate::RaftOneshot;
-use crate::RaftRequestWithSignal;
-use crate::RaftTypeConfig;
-use crate::ReplicationError;
-use crate::RoleEvent;
-use crate::SnapshotError;
-use crate::FOLLOWER;
-use crate::LEADER;
-use crate::LEARNER;
+use d_engine_core::AppendResults;
+use d_engine_core::ConsensusError;
+use d_engine_core::Error;
+use d_engine_core::MaybeCloneOneshot;
+use d_engine_core::MaybeCloneOneshotReceiver;
+use d_engine_core::MaybeCloneOneshotSender;
+use d_engine_core::MockMembership;
+use d_engine_core::MockPurgeExecutor;
+use d_engine_core::MockRaftLog;
+use d_engine_core::MockReplicationCore;
+use d_engine_core::MockStateMachine;
+use d_engine_core::MockStateMachineHandler;
+use d_engine_core::MockTransport;
+use d_engine_core::MockTypeConfig;
+use d_engine_core::NewCommitData;
+use d_engine_core::PeerUpdate;
+use d_engine_core::QuorumVerificationResult;
+use d_engine_core::RaftContext;
+use d_engine_core::RaftEvent;
+use d_engine_core::RaftNodeConfig;
+use d_engine_core::RaftOneshot;
+use d_engine_core::RaftRequestWithSignal;
+use d_engine_core::ReplicationError;
+use d_engine_core::RoleEvent;
+use d_engine_core::SnapshotError;
+use d_engine_core::client_command_to_entry_payloads;
+use d_engine_core::convert::safe_kv_bytes;
+use d_engine_core::leader_state::LeaderState;
+use d_engine_core::role_state::RaftRoleState;
+use d_engine_core::test_utils::MockBuilder;
+use d_engine_core::test_utils::create_test_chunk;
+use d_engine_core::test_utils::create_test_snapshot_stream;
+use d_engine_core::test_utils::mock_raft_context;
+use d_engine_core::test_utils::node_config;
+use d_engine_proto::client::ClientReadRequest;
+use d_engine_proto::client::ClientResponse;
+use d_engine_proto::client::ClientWriteRequest;
+use d_engine_proto::client::ReadConsistencyPolicy;
+use d_engine_proto::common::EntryPayload;
+use d_engine_proto::common::LogId;
+use d_engine_proto::common::NodeRole::Follower;
+use d_engine_proto::common::NodeRole::Leader;
+use d_engine_proto::common::NodeRole::Learner;
+use d_engine_proto::common::NodeStatus;
+use d_engine_proto::error::ErrorCode;
+use d_engine_proto::server::cluster::ClusterConfChangeRequest;
+use d_engine_proto::server::cluster::ClusterMembership;
+use d_engine_proto::server::cluster::JoinRequest;
+use d_engine_proto::server::cluster::LeaderDiscoveryRequest;
+use d_engine_proto::server::cluster::MetadataRequest;
+use d_engine_proto::server::cluster::NodeMeta;
+use d_engine_proto::server::election::VoteRequest;
+use d_engine_proto::server::election::VoteResponse;
+use d_engine_proto::server::replication::AppendEntriesRequest;
+use d_engine_proto::server::storage::PurgeLogRequest;
+use d_engine_proto::server::storage::PurgeLogResponse;
+use d_engine_proto::server::storage::SnapshotMetadata;
 
 struct ProcessRaftRequestTestContext {
     state: LeaderState<MockTypeConfig>,
@@ -364,20 +362,22 @@ async fn test_process_raft_request_case2() {
     let (resp_tx, _resp_rx) = MaybeCloneOneshot::new();
     let (role_tx, _role_rx) = mpsc::unbounded_channel();
 
-    assert!(test_context
-        .state
-        .process_raft_request(
-            RaftRequestWithSignal {
-                id: nanoid!(),
-                payloads: client_command_to_entry_payloads(client_propose_request.commands),
-                sender: resp_tx,
-            },
-            &test_context.raft_context,
-            false,
-            &role_tx
-        )
-        .await
-        .is_ok());
+    assert!(
+        test_context
+            .state
+            .process_raft_request(
+                RaftRequestWithSignal {
+                    id: nanoid!(),
+                    payloads: client_command_to_entry_payloads(client_propose_request.commands),
+                    sender: resp_tx,
+                },
+                &test_context.raft_context,
+                false,
+                &role_tx
+            )
+            .await
+            .is_ok()
+    );
 }
 
 /// # Case 1: state_machine_handler::update_pending should be executed once
@@ -1008,7 +1008,7 @@ async fn test_handle_raft_event_case7() {
     let mut state = LeaderState::<MockTypeConfig>::new(1, context.node_config());
     let (resp_tx, mut resp_rx) = MaybeCloneOneshot::new();
 
-    let stream = crate_test_snapshot_stream(vec![create_test_chunk(0, b"chunk0", 1, 1, 2)]);
+    let stream = create_test_snapshot_stream(vec![create_test_chunk(0, b"chunk0", 1, 1, 2)]);
     let raft_event = RaftEvent::InstallSnapshotChunk(Box::new(stream), resp_tx);
 
     let (role_tx, mut role_rx) = mpsc::unbounded_channel();
@@ -1161,7 +1161,7 @@ mod snapshot_created_event_tests {
             vec![NodeMeta {
                 id: 2,
                 address: "http://127.0.0.1:55001".to_string(),
-                role: FOLLOWER,
+                role: Follower.into(),
                 status: NodeStatus::Active.into(),
             }]
         });
@@ -1213,7 +1213,7 @@ mod snapshot_created_event_tests {
             vec![NodeMeta {
                 id: 2,
                 address: "".to_string(),
-                role: FOLLOWER,
+                role: Follower.into(),
                 status: NodeStatus::Active.into(),
             }]
         });
@@ -1355,7 +1355,7 @@ mod snapshot_created_event_tests {
             vec![NodeMeta {
                 id: 2,
                 address: "http://127.0.0.1:55001".to_string(),
-                role: FOLLOWER,
+                role: Follower.into(),
                 status: NodeStatus::Active.into(),
             }]
         });
@@ -1429,7 +1429,7 @@ mod snapshot_created_event_tests {
             vec![NodeMeta {
                 id: 2,
                 address: "http://127.0.0.1:55001".to_string(),
-                role: FOLLOWER,
+                role: Follower.into(),
                 status: NodeStatus::Active.into(),
             }]
         });
@@ -1501,13 +1501,13 @@ mod snapshot_created_event_tests {
                 NodeMeta {
                     id: 2,
                     address: "http://127.0.0.1:55001".to_string(),
-                    role: FOLLOWER,
+                    role: Follower.into(),
                     status: NodeStatus::Active.into(),
                 },
                 NodeMeta {
                     id: 3,
                     address: "http://127.0.0.1:55002".to_string(),
-                    role: FOLLOWER,
+                    role: Follower.into(),
                     status: NodeStatus::Active.into(),
                 },
             ]
@@ -1653,7 +1653,7 @@ async fn test_handle_raft_event_case10_1_discover_leader_success() {
         Some(NodeMeta {
             id: 1,
             address: "127.0.0.1:50051".to_string(),
-            role: LEADER,
+            role: Leader.into(),
             status: NodeStatus::Active.into(),
         })
     });
@@ -1733,7 +1733,7 @@ async fn test_handle_raft_event_case10_4_different_leader_terms() {
         Some(NodeMeta {
             id: 1,
             address: "127.0.0.1:50051".to_string(),
-            role: LEADER,
+            role: Leader.into(),
             status: NodeStatus::Active.into(),
         })
     });
@@ -1779,7 +1779,7 @@ async fn test_handle_raft_event_case10_5_invalid_node_id() {
         Some(NodeMeta {
             id: 1,
             address: "127.0.0.1:50051".to_string(),
-            role: LEADER,
+            role: Leader.into(),
             status: NodeStatus::Active.into(),
         })
     });
@@ -1810,9 +1810,9 @@ async fn test_handle_raft_event_case10_5_invalid_node_id() {
 fn test_state_size() {
     println!(
         "LeaderState size: {}",
-        size_of::<LeaderState<RaftTypeConfig<MockStorageEngine, MockStateMachine>>>()
+        size_of::<LeaderState<MockTypeConfig>>()
     );
-    assert!(size_of::<LeaderState<RaftTypeConfig<MockStorageEngine, MockStateMachine>>>() <= 360);
+    assert!(size_of::<LeaderState<MockTypeConfig>>() <= 360);
 }
 
 /// # Case 1: Valid purge conditions with cluster consensus
@@ -2137,13 +2137,13 @@ async fn test_process_batch_case2_2_quorum_non_verifiable_failure() {
         vec![
             NodeMeta {
                 id: 2,
-                role: FOLLOWER,
+                role: Follower.into(),
                 address: "127.0.0.1:0".to_string(),
                 status: NodeStatus::Active.into(),
             },
             NodeMeta {
                 id: 3,
-                role: FOLLOWER,
+                role: Follower.into(),
                 address: "127.0.0.1:0".to_string(),
                 status: NodeStatus::Active.into(),
             },
@@ -2251,13 +2251,13 @@ async fn test_process_batch_case4_partial_timeouts() {
             NodeMeta {
                 id: 2,
                 address: "http://127.0.0.1:55001".to_string(),
-                role: FOLLOWER,
+                role: Follower.into(),
                 status: NodeStatus::Active.into(),
             },
             NodeMeta {
                 id: 3,
                 address: "http://127.0.0.1:55002".to_string(),
-                role: FOLLOWER,
+                role: Follower.into(),
                 status: NodeStatus::Active.into(),
             },
         ]
@@ -2311,13 +2311,13 @@ async fn test_process_batch_case5_all_timeout() {
             NodeMeta {
                 id: 2,
                 address: "http://127.0.0.1:55001".to_string(),
-                role: FOLLOWER,
+                role: Follower.into(),
                 status: NodeStatus::Active.into(),
             },
             NodeMeta {
                 id: 3,
                 address: "http://127.0.0.1:55002".to_string(),
-                role: FOLLOWER,
+                role: Follower.into(),
                 status: NodeStatus::Active.into(),
             },
         ]
@@ -2520,19 +2520,19 @@ async fn test_verify_internal_quorum_case3_non_verifiable_failure() {
             NodeMeta {
                 id: 2,
                 address: "".to_string(),
-                role: FOLLOWER,
+                role: Follower.into(),
                 status: NodeStatus::Active.into(),
             },
             NodeMeta {
                 id: 3,
                 address: "".to_string(),
-                role: FOLLOWER,
+                role: Follower.into(),
                 status: NodeStatus::Active.into(),
             },
             NodeMeta {
                 id: 4,
                 address: "".to_string(),
-                role: FOLLOWER,
+                role: Follower.into(),
                 status: NodeStatus::Active.into(),
             },
         ]
@@ -2723,7 +2723,7 @@ async fn test_handle_join_cluster_case1_success() {
         vec![NodeMeta {
             id: 2,
             address: "http://127.0.0.1:55001".to_string(),
-            role: FOLLOWER,
+            role: Follower.into(),
             status: NodeStatus::Active.into(),
         }]
     });
@@ -2786,7 +2786,7 @@ async fn test_handle_join_cluster_case1_success() {
         .handle_join_cluster(
             JoinRequest {
                 node_id,
-                node_role: LEARNER,
+                node_role: Learner.into(),
                 address: address.clone(),
             },
             sender,
@@ -2828,7 +2828,7 @@ async fn test_handle_join_cluster_case2_node_exists() {
         .handle_join_cluster(
             JoinRequest {
                 node_id,
-                node_role: LEARNER,
+                node_role: Learner.into(),
                 address: "127.0.0.1:8080".to_string(),
             },
             sender,
@@ -2884,7 +2884,7 @@ async fn test_handle_join_cluster_case3_quorum_failed() {
         .handle_join_cluster(
             JoinRequest {
                 node_id,
-                node_role: LEARNER,
+                node_role: Learner.into(),
                 address: "127.0.0.1:8080".to_string(),
             },
             sender,
@@ -2921,7 +2921,7 @@ async fn test_handle_join_cluster_case4_quorum_error() {
         vec![NodeMeta {
             id: 2,
             address: "http://127.0.0.1:55001".to_string(),
-            role: FOLLOWER,
+            role: Follower.into(),
             status: NodeStatus::Active.into(),
         }]
     });
@@ -2941,7 +2941,7 @@ async fn test_handle_join_cluster_case4_quorum_error() {
         .handle_join_cluster(
             JoinRequest {
                 node_id,
-                node_role: LEARNER,
+                node_role: Learner.into(),
                 address: "127.0.0.1:8080".to_string(),
             },
             sender,
@@ -2984,7 +2984,7 @@ async fn test_handle_join_cluster_case5_snapshot_triggered() {
         vec![NodeMeta {
             id: 2,
             address: "http://127.0.0.1:55001".to_string(),
-            role: FOLLOWER,
+            role: Follower.into(),
             status: NodeStatus::Active.into(),
         }]
     });
@@ -3041,7 +3041,7 @@ async fn test_handle_join_cluster_case5_snapshot_triggered() {
         .handle_join_cluster(
             JoinRequest {
                 node_id,
-                node_role: LEARNER,
+                node_role: Learner.into(),
                 address,
             },
             sender,
@@ -3057,15 +3057,14 @@ async fn test_handle_join_cluster_case5_snapshot_triggered() {
 
 #[cfg(test)]
 mod trigger_background_snapshot_test {
-    use std::sync::Arc;
-
     use futures::stream;
+    use std::sync::Arc;
 
     use super::*;
-    use crate::core::raft_role::leader_state::LeaderState;
-    use crate::proto::storage::SnapshotChunk;
-    use crate::proto::storage::SnapshotMetadata;
-    use crate::SnapshotConfig;
+    use d_engine_core::SnapshotConfig;
+    use d_engine_core::leader_state::LeaderState;
+    use d_engine_proto::server::storage::SnapshotChunk;
+    use d_engine_proto::server::storage::SnapshotMetadata;
 
     fn mock_membership(should_fail: bool) -> MockMembership<MockTypeConfig> {
         let mut membership = MockMembership::<MockTypeConfig>::new();
@@ -3083,7 +3082,7 @@ mod trigger_background_snapshot_test {
         let mut handler = MockStateMachineHandler::<MockTypeConfig>::new();
         handler.expect_load_snapshot_data().returning(move |_| {
             if should_fail {
-                Err(crate::SnapshotError::OperationFailed("mock error".to_string()).into())
+                Err(d_engine_core::SnapshotError::OperationFailed("mock error".to_string()).into())
             } else {
                 let chunk = SnapshotChunk {
                     data: Bytes::from(vec![1, 2, 3]),
@@ -3106,7 +3105,7 @@ mod trigger_background_snapshot_test {
 
     fn make_metadata() -> SnapshotMetadata {
         SnapshotMetadata {
-            last_included: Some(crate::proto::common::LogId { index: 1, term: 1 }),
+            last_included: Some(d_engine_proto::common::LogId { index: 1, term: 1 }),
             ..Default::default()
         }
     }
@@ -3119,7 +3118,7 @@ mod trigger_background_snapshot_test {
         let config = default_snapshot_config();
         let metadata = make_metadata();
 
-        let result = LeaderState::<crate::test_utils::MockTypeConfig>::trigger_background_snapshot(
+        let result = LeaderState::<MockTypeConfig>::trigger_background_snapshot(
             2, metadata, sm_handler, membership, config,
         )
         .await;
@@ -3135,7 +3134,7 @@ mod trigger_background_snapshot_test {
         let config = default_snapshot_config();
         let metadata = make_metadata();
 
-        let result = LeaderState::<crate::test_utils::MockTypeConfig>::trigger_background_snapshot(
+        let result = LeaderState::<MockTypeConfig>::trigger_background_snapshot(
             2, metadata, sm_handler, membership, config,
         )
         .await;
@@ -3151,7 +3150,7 @@ mod trigger_background_snapshot_test {
         let config = default_snapshot_config();
         let metadata = make_metadata();
 
-        let result = LeaderState::<crate::test_utils::MockTypeConfig>::trigger_background_snapshot(
+        let result = LeaderState::<MockTypeConfig>::trigger_background_snapshot(
             2, metadata, sm_handler, membership, config,
         )
         .await;
@@ -3167,11 +3166,11 @@ mod batch_promote_learners_test {
     use mockall::predicate::*;
 
     use super::*;
-    use crate::core::raft_role::leader_state::LeaderState;
-    use crate::core::raft_role::RoleEvent;
-    use crate::membership::MockMembership;
-    use crate::proto::common::NodeStatus;
-    use crate::RaftContext;
+    use d_engine_core::MockMembership;
+    use d_engine_core::RaftContext;
+    use d_engine_core::RoleEvent;
+    use d_engine_core::leader_state::LeaderState;
+    use d_engine_proto::common::NodeStatus;
 
     enum VerifyInternalQuorumWithRetrySuccess {
         Success,
@@ -3208,7 +3207,7 @@ mod batch_promote_learners_test {
                 .map(|id| NodeMeta {
                     id: id as u32,
                     address: format!("addr_{id}"),
-                    role: FOLLOWER,
+                    role: Follower.into(),
                     status: NodeStatus::Active.into(),
                 })
                 .collect()
@@ -3366,12 +3365,12 @@ mod pending_promotion_tests {
 
     use bytes::Bytes;
     use parking_lot::Mutex;
-    use tokio::time::timeout;
     use tokio::time::Instant;
+    use tokio::time::timeout;
 
     use super::*;
-    use crate::leader_state::calculate_safe_batch_size;
-    use crate::leader_state::PendingPromotion;
+    use d_engine_core::leader_state::PendingPromotion;
+    use d_engine_core::leader_state::calculate_safe_batch_size;
 
     // Test fixture
     struct TestFixture {
@@ -3409,7 +3408,7 @@ mod pending_promotion_tests {
                         id,
                         address: "".to_string(),
                         status: NodeStatus::Active as i32,
-                        role: FOLLOWER,
+                        role: Follower.into(),
                     })
                     .collect()
             });
@@ -3579,11 +3578,13 @@ mod pending_promotion_tests {
     #[tokio::test]
     async fn test_handle_stale_learner() {
         let mut fixture = TestFixture::new("test_handle_stale_learner", true).await;
-        assert!(fixture
-            .leader_state
-            .handle_stale_learner(1, &fixture.raft_context)
-            .await
-            .is_ok());
+        assert!(
+            fixture
+                .leader_state
+                .handle_stale_learner(1, &fixture.raft_context)
+                .await
+                .is_ok()
+        );
     }
 
     #[tokio::test]
@@ -3599,7 +3600,7 @@ mod pending_promotion_tests {
                     id,
                     address: "".to_string(),
                     status: NodeStatus::Active as i32,
-                    role: FOLLOWER,
+                    role: Follower.into(),
                 })
                 .collect()
         });
@@ -3739,14 +3740,12 @@ mod pending_promotion_tests {
 mod stale_learner_tests {
     use std::sync::Arc;
     use std::time::Duration;
-
     use tokio::time::Instant;
 
     use super::*;
-    use crate::leader_state::PendingPromotion;
-    use crate::test_utils;
-    use crate::test_utils::*;
-    use crate::RaftNodeConfig; // Assuming you have test utilities
+    use d_engine_core::RaftNodeConfig;
+    use d_engine_core::leader_state::PendingPromotion;
+    use d_engine_core::test_utils;
 
     // Setup helper
     fn create_test_leader_state(
@@ -3945,9 +3944,9 @@ mod stale_learner_tests {
 #[cfg(test)]
 mod handle_client_read_request {
     use super::*;
-    use crate::config::ReadConsistencyPolicy as ServerPolicy;
-    use crate::convert::safe_kv_bytes;
-    use crate::proto::client::ReadConsistencyPolicy as ClientPolicy;
+    use d_engine_core::config::ReadConsistencyPolicy as ServerPolicy;
+    use d_engine_core::convert::safe_kv_bytes;
+    use d_engine_proto::client::ReadConsistencyPolicy as ClientPolicy;
 
     /// Test LeaseRead policy with valid lease
     #[tokio::test]
@@ -4177,8 +4176,8 @@ mod handle_client_read_request {
 #[cfg(test)]
 mod lease_validity_tests {
     use super::*;
-    use crate::test_utils::MockBuilder;
-    use crate::RaftNodeConfig;
+    use d_engine_core::RaftNodeConfig;
+    use d_engine_core::test_utils::MockBuilder;
     use std::sync::Arc;
     use std::time::{SystemTime, UNIX_EPOCH};
     use tokio::sync::watch;
diff --git a/src/core/raft_role/learner_state_test.rs b/d-engine-server/tests/components/raft_role/learner_state_test.rs
similarity index 94%
rename from src/core/raft_role/learner_state_test.rs
rename to d-engine-server/tests/components/raft_role/learner_state_test.rs
index 42070f52..e5e9a30a 100644
--- a/src/core/raft_role/learner_state_test.rs
+++ b/d-engine-server/tests/components/raft_role/learner_state_test.rs
@@ -1,51 +1,50 @@
+use bytes::Bytes;
 use std::sync::Arc;
 use std::thread::sleep;
 use std::time::Duration;
-
-use bytes::Bytes;
 use tokio::sync::mpsc;
 use tokio::sync::watch;
 use tonic::Code;
 use tracing::debug;
 use tracing_test::traced_test;
 
-use crate::learner_state::LearnerState;
-use crate::proto::client::ClientReadRequest;
-use crate::proto::client::ClientWriteRequest;
-use crate::proto::cluster::cluster_conf_update_response;
-use crate::proto::cluster::ClusterConfChangeRequest;
-use crate::proto::cluster::ClusterConfUpdateResponse;
-use crate::proto::cluster::JoinRequest;
-use crate::proto::cluster::JoinResponse;
-use crate::proto::cluster::LeaderDiscoveryRequest;
-use crate::proto::cluster::LeaderDiscoveryResponse;
-use crate::proto::cluster::MetadataRequest;
-use crate::proto::common::LogId;
-use crate::proto::election::VoteRequest;
-use crate::proto::error::ErrorCode;
-use crate::proto::replication::AppendEntriesRequest;
-use crate::proto::replication::AppendEntriesResponse;
-use crate::proto::storage::PurgeLogRequest;
-use crate::role_state::RaftRoleState;
-use crate::test_utils::mock_membership;
-use crate::test_utils::mock_raft_context;
-use crate::test_utils::MockTypeConfig;
-use crate::AppendResponseWithUpdates;
-use crate::ConsensusError;
-use crate::Error;
-use crate::MaybeCloneOneshot;
-use crate::MembershipError;
-use crate::MockMembership;
-use crate::MockReplicationCore;
-use crate::MockTransport;
-use crate::NetworkError;
-use crate::NewCommitData;
-use crate::RaftContext;
-use crate::RaftEvent;
-use crate::RaftOneshot;
-use crate::RoleEvent;
-use crate::SystemError;
-use crate::LEARNER;
+use d_engine_core::AppendResponseWithUpdates;
+use d_engine_core::ConsensusError;
+use d_engine_core::Error;
+use d_engine_core::MaybeCloneOneshot;
+use d_engine_core::MembershipError;
+use d_engine_core::MockMembership;
+use d_engine_core::MockReplicationCore;
+use d_engine_core::MockTransport;
+use d_engine_core::MockTypeConfig;
+use d_engine_core::NetworkError;
+use d_engine_core::NewCommitData;
+use d_engine_core::RaftContext;
+use d_engine_core::RaftEvent;
+use d_engine_core::RaftOneshot;
+use d_engine_core::RoleEvent;
+use d_engine_core::SystemError;
+use d_engine_core::learner_state::LearnerState;
+use d_engine_core::role_state::RaftRoleState;
+use d_engine_core::test_utils::mock_membership;
+use d_engine_core::test_utils::mock_raft_context;
+use d_engine_proto::client::ClientReadRequest;
+use d_engine_proto::client::ClientWriteRequest;
+use d_engine_proto::common::LogId;
+use d_engine_proto::common::NodeRole::Learner;
+use d_engine_proto::error::ErrorCode;
+use d_engine_proto::server::cluster::ClusterConfChangeRequest;
+use d_engine_proto::server::cluster::ClusterConfUpdateResponse;
+use d_engine_proto::server::cluster::JoinRequest;
+use d_engine_proto::server::cluster::JoinResponse;
+use d_engine_proto::server::cluster::LeaderDiscoveryRequest;
+use d_engine_proto::server::cluster::LeaderDiscoveryResponse;
+use d_engine_proto::server::cluster::MetadataRequest;
+use d_engine_proto::server::cluster::cluster_conf_update_response;
+use d_engine_proto::server::election::VoteRequest;
+use d_engine_proto::server::replication::AppendEntriesRequest;
+use d_engine_proto::server::replication::AppendEntriesResponse;
+use d_engine_proto::server::storage::PurgeLogRequest;
 
 /// Validate Follower step up as Candidate in new election round
 #[tokio::test]
@@ -151,7 +150,7 @@ async fn test_handle_raft_event_case3() {
     // Prepare function params
     let (resp_tx, mut resp_rx) = MaybeCloneOneshot::new();
     let (role_tx, _role_rx) = mpsc::unbounded_channel();
-    let raft_event = crate::RaftEvent::ClusterConfUpdate(
+    let raft_event = d_engine_core::RaftEvent::ClusterConfUpdate(
         ClusterConfChangeRequest {
             id: 2, // Leader ID
             term: 1,
@@ -516,7 +515,7 @@ async fn test_handle_raft_event_case10() {
     // Step 2: Prepare the event
     let request = JoinRequest {
         node_id: 2,
-        node_role: LEARNER,
+        node_role: Learner.into(),
         address: "127.0.0.1:9090".to_string(),
     };
     let (resp_tx, mut resp_rx) = MaybeCloneOneshot::new();
@@ -627,9 +626,8 @@ fn mock_context(
 ) -> RaftContext<MockTypeConfig> {
     let temp_dir = tempfile::tempdir().unwrap();
     let case_path = temp_dir.path().join(case_name);
-    let raft_context = mock_raft_context(case_path.to_str().unwrap(), shutdown_signal, None);
 
-    raft_context
+    mock_raft_context(case_path.to_str().unwrap(), shutdown_signal, None)
 }
 
 /// Tests leader selection with multiple valid responses
diff --git a/d-engine-server/tests/components/raft_role/mod.rs b/d-engine-server/tests/components/raft_role/mod.rs
new file mode 100644
index 00000000..7e8fe882
--- /dev/null
+++ b/d-engine-server/tests/components/raft_role/mod.rs
@@ -0,0 +1,8 @@
+#[cfg(test)]
+mod candidate_state_test;
+#[cfg(test)]
+mod follower_state_test;
+#[cfg(test)]
+mod leader_state_test;
+#[cfg(test)]
+mod learner_state_test;
diff --git a/src/core/raft_test.rs b/d-engine-server/tests/components/raft_test.rs
similarity index 95%
rename from src/core/raft_test.rs
rename to d-engine-server/tests/components/raft_test.rs
index bd4d129b..5a661a46 100644
--- a/src/core/raft_test.rs
+++ b/d-engine-server/tests/components/raft_test.rs
@@ -1,38 +1,45 @@
+use d_engine_core::MockReplicationCore;
+use d_engine_core::RaftEvent;
 use std::collections::HashMap;
 use std::sync::Arc;
 use std::time::Duration;
-
 use tokio::sync::mpsc;
 use tokio::sync::watch;
 use tokio::time;
 use tokio::time::timeout;
 use tracing_test::traced_test;
 
-use super::*;
-use crate::candidate_state::CandidateState;
-use crate::cluster::is_candidate;
-use crate::cluster::is_follower;
-use crate::cluster::is_leader;
-use crate::cluster::is_learner;
-use crate::leader_state::LeaderState;
-use crate::proto::cluster::MetadataRequest;
-use crate::proto::cluster::NodeMeta;
-use crate::proto::common::NodeStatus;
-use crate::proto::election::VoteResponse;
-use crate::test_utils::mock_raft;
-use crate::test_utils::MockTypeConfig;
-use crate::AppendResults;
-use crate::ConsensusError;
-use crate::ElectionError;
-use crate::Error;
-use crate::MaybeCloneOneshot;
-use crate::MockElectionCore;
-use crate::MockMembership;
-use crate::MockRaftLog;
-use crate::MockTransport;
-use crate::PeerUpdate;
-use crate::RaftOneshot;
-use crate::VoteResult;
+use d_engine_core::AppendResults;
+use d_engine_core::ConsensusError;
+use d_engine_core::ElectionError;
+use d_engine_core::Error;
+use d_engine_core::MaybeCloneOneshot;
+use d_engine_core::MockElectionCore;
+use d_engine_core::MockMembership;
+use d_engine_core::MockRaftLog;
+use d_engine_core::MockTransport;
+use d_engine_core::MockTypeConfig;
+use d_engine_core::NewCommitData;
+use d_engine_core::PeerUpdate;
+use d_engine_core::RaftOneshot;
+use d_engine_core::RaftRole;
+use d_engine_core::RoleEvent;
+use d_engine_core::TestEvent;
+use d_engine_core::VoteResult;
+use d_engine_core::candidate_state::CandidateState;
+use d_engine_core::cluster::is_candidate;
+use d_engine_core::cluster::is_follower;
+use d_engine_core::cluster::is_leader;
+use d_engine_core::cluster::is_learner;
+use d_engine_core::leader_state::LeaderState;
+use d_engine_proto::common::NodeRole::Candidate;
+use d_engine_proto::common::NodeRole::Follower;
+use d_engine_proto::common::NodeRole::Leader;
+use d_engine_proto::common::NodeStatus;
+use d_engine_proto::server::cluster::MetadataRequest;
+use d_engine_proto::server::cluster::NodeMeta;
+use d_engine_proto::server::election::VoteResponse;
+use d_engine_server::test_utils::mock_raft;
 
 /// # Case 1: Tick has higher priority than role event
 #[tokio::test]
@@ -47,7 +54,7 @@ async fn test_tick_priority_over_role_event() {
     raft.ctx.storage.raft_log = Arc::new(raft_log);
     raft.ctx.handlers.replication_handler = replication_core;
     // 2. Add state listeners
-    let role_tx = raft.role_tx.clone();
+    let role_tx = raft.role_event_sender();
     let (monitor_tx, mut monitor_rx) = mpsc::unbounded_channel::<i32>();
     raft.register_role_transition_listener(monitor_tx);
 
@@ -95,8 +102,8 @@ async fn test_role_event_priority_over_event_rx() {
     raft.ctx.handlers.replication_handler = replication_core;
 
     // 2. Add state listeners
-    let raft_tx = raft.event_tx.clone();
-    let role_tx = raft.role_tx.clone();
+    let raft_tx = raft.event_sender();
+    let role_tx = raft.role_event_sender();
     let (monitor_tx, mut monitor_rx) = mpsc::unbounded_channel::<i32>();
     raft.register_role_transition_listener(monitor_tx.clone());
     let (event_monitor_tx, mut event_monitor_rx) = mpsc::unbounded_channel::<TestEvent>();
@@ -396,13 +403,13 @@ async fn test_election_timeout_case4() {
             NodeMeta {
                 id: peer1_id,
                 address: "http://127.0.0.1:55001".to_string(),
-                role: FOLLOWER,
+                role: Follower.into(),
                 status: NodeStatus::Active.into(),
             },
             NodeMeta {
                 id: peer2_id,
                 address: "http://127.0.0.1:55002".to_string(),
-                role: CANDIDATE,
+                role: Candidate.into(),
                 status: NodeStatus::Active.into(),
             },
         ]
@@ -730,7 +737,7 @@ async fn test_handle_role_event_state_update_case1_1() {
     raft.register_new_commit_listener(tx);
     raft.handle_role_event(RoleEvent::NotifyNewCommitIndex(NewCommitData {
         new_commit_index,
-        role: LEADER,
+        role: Leader.into(),
         current_term: 1,
     }))
     .await
@@ -760,7 +767,7 @@ async fn test_handle_role_event_state_update_case1_2() {
     raft.register_new_commit_listener(tx);
     raft.handle_role_event(RoleEvent::NotifyNewCommitIndex(NewCommitData {
         new_commit_index,
-        role: LEADER,
+        role: Leader.into(),
         current_term: 1,
     }))
     .await
@@ -800,7 +807,7 @@ async fn test_handle_role_event_state_update_case1_3_1() {
     raft.register_new_commit_listener(tx);
     raft.handle_role_event(RoleEvent::NotifyNewCommitIndex(NewCommitData {
         new_commit_index,
-        role: LEADER,
+        role: Leader.into(),
         current_term: 1,
     }))
     .await
@@ -831,7 +838,7 @@ async fn test_handle_role_event_state_update_case1_3_2() {
         vec![NodeMeta {
             id: 2,
             address: "http://127.0.0.1:55001".to_string(),
-            role: FOLLOWER,
+            role: Follower.into(),
             status: NodeStatus::Active.into(),
         }]
     });
@@ -912,7 +919,7 @@ async fn test_handle_role_event_state_update_case1_4() {
     raft.register_new_commit_listener(tx);
     raft.handle_role_event(RoleEvent::NotifyNewCommitIndex(NewCommitData {
         new_commit_index,
-        role: LEADER,
+        role: Leader.into(),
         current_term: 1,
     }))
     .await
@@ -993,7 +1000,7 @@ async fn test_handle_role_event_state_update_case1_5_1() {
     raft.ctx.handlers.replication_handler = replication_handler;
 
     // 2. Add state listeners
-    let role_tx = raft.role_tx.clone();
+    let role_tx = raft.role_event_sender();
     let (monitor_tx, mut monitor_rx) = mpsc::unbounded_channel::<i32>();
     raft.register_role_transition_listener(monitor_tx);
 
@@ -1051,7 +1058,7 @@ async fn test_handle_role_event_state_update_case1_5_2() {
     raft.ctx.handlers.replication_handler = replication_core;
 
     // 2. Add state listeners
-    let role_tx = raft.role_tx.clone();
+    let role_tx = raft.role_event_sender();
     let (monitor_tx, mut monitor_rx) = mpsc::unbounded_channel::<i32>();
     raft.register_role_transition_listener(monitor_tx);
 
diff --git a/d-engine-server/tests/components/replication/mod.rs b/d-engine-server/tests/components/replication/mod.rs
new file mode 100644
index 00000000..13c10a49
--- /dev/null
+++ b/d-engine-server/tests/components/replication/mod.rs
@@ -0,0 +1 @@
+mod replication_handler_test;
diff --git a/src/core/replication/replication_handler_test.rs b/d-engine-server/tests/components/replication/replication_handler_test.rs
similarity index 95%
rename from src/core/replication/replication_handler_test.rs
rename to d-engine-server/tests/components/replication/replication_handler_test.rs
index 78b1bbab..28bfe0e5 100644
--- a/src/core/replication/replication_handler_test.rs
+++ b/d-engine-server/tests/components/replication/replication_handler_test.rs
@@ -9,50 +9,50 @@ use tokio::sync::watch;
 use tracing::debug;
 use tracing_test::traced_test;
 
-use super::ReplicationCore;
-use super::ReplicationData;
-use super::ReplicationHandler;
-use crate::client_command_to_entry_payloads;
-use crate::convert::safe_kv_bytes;
-use crate::proto::client::write_command::Insert;
-use crate::proto::client::write_command::Operation;
-use crate::proto::client::WriteCommand;
-use crate::proto::cluster::NodeMeta;
-use crate::proto::common::entry_payload::Payload;
-use crate::proto::common::Entry;
-use crate::proto::common::EntryPayload;
-use crate::proto::common::LogId;
-use crate::proto::common::NodeStatus;
-use crate::proto::replication::append_entries_response;
-use crate::proto::replication::AppendEntriesRequest;
-use crate::proto::replication::AppendEntriesResponse;
-use crate::proto::replication::ConflictResult;
-use crate::proto::replication::SuccessResult;
-use crate::test_utils::generate_insert_commands;
-use crate::test_utils::mock_raft_context;
-use crate::test_utils::setup_raft_components;
-use crate::test_utils::simulate_insert_command;
-use crate::test_utils::MockTypeConfig;
-use crate::AppendResult;
-use crate::ConsensusError;
-use crate::Error;
-use crate::FileStorageEngine;
-use crate::LeaderStateSnapshot;
-use crate::MockMembership;
-use crate::MockRaftLog;
-use crate::MockStateMachine;
-use crate::MockTransport;
-use crate::NetworkError;
-use crate::PeerUpdate;
-use crate::RaftLog;
-use crate::RaftTypeConfig;
-use crate::ReplicationError;
-use crate::StateSnapshot;
-use crate::StorageError;
-use crate::SystemError;
-use crate::FOLLOWER;
-use crate::LEADER;
-use crate::LEARNER;
+use d_engine_core::AppendResult;
+use d_engine_core::ConsensusError;
+use d_engine_core::Error;
+use d_engine_core::LeaderStateSnapshot;
+use d_engine_core::MockMembership;
+use d_engine_core::MockRaftLog;
+use d_engine_core::MockStateMachine;
+use d_engine_core::MockTransport;
+use d_engine_core::MockTypeConfig;
+use d_engine_core::NetworkError;
+use d_engine_core::PeerUpdate;
+use d_engine_core::RaftLog;
+use d_engine_core::ReplicationCore;
+use d_engine_core::ReplicationData;
+use d_engine_core::ReplicationError;
+use d_engine_core::ReplicationHandler;
+use d_engine_core::StateSnapshot;
+use d_engine_core::StorageError;
+use d_engine_core::SystemError;
+use d_engine_core::client_command_to_entry_payloads;
+use d_engine_core::convert::safe_kv_bytes;
+use d_engine_core::test_utils::generate_insert_commands;
+use d_engine_core::test_utils::mock_raft_context;
+use d_engine_proto::client::WriteCommand;
+use d_engine_proto::client::write_command::Insert;
+use d_engine_proto::client::write_command::Operation;
+use d_engine_proto::common::Entry;
+use d_engine_proto::common::EntryPayload;
+use d_engine_proto::common::LogId;
+use d_engine_proto::common::NodeRole::Follower;
+use d_engine_proto::common::NodeRole::Leader;
+use d_engine_proto::common::NodeRole::Learner;
+use d_engine_proto::common::NodeStatus;
+use d_engine_proto::common::entry_payload::Payload;
+use d_engine_proto::server::cluster::NodeMeta;
+use d_engine_proto::server::replication::AppendEntriesRequest;
+use d_engine_proto::server::replication::AppendEntriesResponse;
+use d_engine_proto::server::replication::ConflictResult;
+use d_engine_proto::server::replication::SuccessResult;
+use d_engine_proto::server::replication::append_entries_response;
+use d_engine_server::FileStorageEngine;
+use d_engine_server::node::RaftTypeConfig;
+use d_engine_server::test_utils::setup_raft_components;
+use d_engine_server::test_utils::simulate_insert_command;
 
 /// # Case 1: The peer3's next_index is equal to
 ///     the end of the leader's old log,
@@ -521,9 +521,11 @@ fn test_stale_term() {
         leader_id: 2,
     };
 
-    assert!(handler
-        .check_append_entries_request_is_legal(my_term, &request, &Arc::new(raft_log))
-        .is_higher_term());
+    assert!(
+        handler
+            .check_append_entries_request_is_legal(my_term, &request, &Arc::new(raft_log))
+            .is_higher_term()
+    );
 }
 
 /// # Case 1: follower local raft log length > prev_log_index
@@ -622,9 +624,11 @@ fn test_virtual_log_handling() {
         leader_id: 2,
     };
 
-    assert!(handler
-        .check_append_entries_request_is_legal(my_term, &request, &Arc::new(raft_log))
-        .is_success());
+    assert!(
+        handler
+            .check_append_entries_request_is_legal(my_term, &request, &Arc::new(raft_log))
+            .is_success()
+    );
 }
 #[test]
 fn test_virtual_log_with_non_empty_log() {
@@ -860,9 +864,9 @@ mod handle_raft_request_in_batch_test {
     use tracing::debug;
 
     use super::*;
-    use crate::convert::safe_kv_bytes;
-    use crate::test_utils::node_config;
-    use crate::test_utils::MockBuilder;
+    use d_engine_core::convert::safe_kv_bytes;
+    use d_engine_core::test_utils::node_config;
+    use d_engine_server::test_utils::MockBuilder;
 
     /// # Case 1: No peers found
     /// ## Validation Criteria
@@ -884,7 +888,7 @@ mod handle_raft_request_in_batch_test {
             current_term: 1,
             voted_for: None,
             commit_index: 1,
-            role: LEADER,
+            role: Leader.into(),
         };
         let leader_state_snapshot = LeaderStateSnapshot {
             next_index: HashMap::new(),
@@ -924,7 +928,7 @@ mod handle_raft_request_in_batch_test {
             current_term: 1,
             voted_for: None,
             commit_index: 1,
-            role: LEADER,
+            role: Leader.into(),
         };
         let leader_state_snapshot = LeaderStateSnapshot {
             next_index: HashMap::new(),
@@ -937,7 +941,7 @@ mod handle_raft_request_in_batch_test {
             vec![NodeMeta {
                 id: peer2_id,
                 address: "http://127.0.0.1:55001".to_string(),
-                role: FOLLOWER,
+                role: Follower.into(),
                 status: NodeStatus::Active.into(),
             }]
         });
@@ -945,7 +949,7 @@ mod handle_raft_request_in_batch_test {
             vec![NodeMeta {
                 id: peer2_id,
                 address: "http://127.0.0.1:55001".to_string(),
-                role: FOLLOWER,
+                role: Follower.into(),
                 status: NodeStatus::Active.into(),
             }]
         });
@@ -1004,7 +1008,7 @@ mod handle_raft_request_in_batch_test {
             current_term: 1,
             voted_for: None,
             commit_index: 1,
-            role: LEADER,
+            role: Leader.into(),
         };
         let leader_state_snapshot = LeaderStateSnapshot {
             next_index: HashMap::new(),
@@ -1069,7 +1073,7 @@ mod handle_raft_request_in_batch_test {
             current_term: 2, // Leader's term is 2
             voted_for: None,
             commit_index: 1,
-            role: LEADER,
+            role: Leader.into(),
         };
         let leader_state_snapshot = LeaderStateSnapshot {
             next_index: HashMap::from_iter(vec![(peer2_id, 3)]),
@@ -1102,7 +1106,7 @@ mod handle_raft_request_in_batch_test {
             vec![NodeMeta {
                 id: peer2_id,
                 address: "http://127.0.0.1:55001".to_string(),
-                role: FOLLOWER,
+                role: Follower.into(),
                 status: NodeStatus::Active.into(),
             }]
         });
@@ -1138,7 +1142,7 @@ mod handle_raft_request_in_batch_test {
             current_term: 1,
             voted_for: None,
             commit_index: 1,
-            role: LEADER,
+            role: Leader.into(),
         };
         let leader_state_snapshot = LeaderStateSnapshot {
             next_index: HashMap::new(),
@@ -1170,7 +1174,7 @@ mod handle_raft_request_in_batch_test {
             vec![NodeMeta {
                 id: peer2_id,
                 address: "http://127.0.0.1:55001".to_string(),
-                role: FOLLOWER,
+                role: Follower.into(),
                 status: NodeStatus::Active.into(),
             }]
         });
@@ -1225,7 +1229,7 @@ mod handle_raft_request_in_batch_test {
             current_term: 1,
             voted_for: None,
             commit_index: 5,
-            role: LEADER,
+            role: Leader.into(),
         };
         let leader_state_snapshot = LeaderStateSnapshot {
             next_index: HashMap::from([(peer2_id, 6)]),
@@ -1261,7 +1265,7 @@ mod handle_raft_request_in_batch_test {
         membership.expect_replication_peers().returning(move || {
             vec![NodeMeta {
                 id: peer2_id,
-                role: FOLLOWER,
+                role: Follower.into(),
                 address: "".to_string(),
                 status: NodeStatus::Active.into(),
             }]
@@ -1334,7 +1338,7 @@ mod handle_raft_request_in_batch_test {
             current_term: 6,
             voted_for: None,
             commit_index: 10,
-            role: LEADER,
+            role: Leader.into(),
         };
 
         // Initial next_index values from test case description
@@ -1422,7 +1426,7 @@ mod handle_raft_request_in_batch_test {
                 NodeMeta {
                     id: id as u32,
                     address: "http://127.0.0.1:55001".to_string(),
-                    role: FOLLOWER,
+                    role: Follower.into(),
                     status: NodeStatus::Active.into(),
                 }
             })
@@ -1564,7 +1568,7 @@ mod handle_raft_request_in_batch_test {
             current_term: 1,
             voted_for: None,
             commit_index: 5,
-            role: LEADER,
+            role: Leader.into(),
         };
         let leader_state_snapshot = LeaderStateSnapshot {
             next_index: HashMap::from([(peer2_id, 6), (peer3_id, 6), (peer4_id, 6), (peer5_id, 6)]),
@@ -1618,25 +1622,25 @@ mod handle_raft_request_in_batch_test {
                 NodeMeta {
                     id: peer2_id,
                     address: "http://127.0.0.1:55001".to_string(),
-                    role: FOLLOWER,
+                    role: Follower.into(),
                     status: NodeStatus::Active.into(),
                 },
                 NodeMeta {
                     id: peer3_id,
                     address: "http://127.0.0.1:55002".to_string(),
-                    role: FOLLOWER,
+                    role: Follower.into(),
                     status: NodeStatus::Active.into(),
                 },
                 NodeMeta {
                     id: peer4_id,
                     address: "http://127.0.0.1:55003".to_string(),
-                    role: FOLLOWER,
+                    role: Follower.into(),
                     status: NodeStatus::Active.into(),
                 },
                 NodeMeta {
                     id: peer5_id,
                     address: "http://127.0.0.1:55004".to_string(),
-                    role: FOLLOWER,
+                    role: Follower.into(),
                     status: NodeStatus::Active.into(),
                 },
             ]
@@ -1727,7 +1731,7 @@ mod handle_raft_request_in_batch_test {
             current_term: 1,
             voted_for: None,
             commit_index: 5,
-            role: LEADER,
+            role: Leader.into(),
         };
         let leader_state_snapshot = LeaderStateSnapshot {
             next_index: HashMap::from([(peer2_id, 6), (peer3_id, 6)]),
@@ -1771,13 +1775,13 @@ mod handle_raft_request_in_batch_test {
                 NodeMeta {
                     id: peer2_id,
                     address: "http://127.0.0.1:55001".to_string(),
-                    role: FOLLOWER,
+                    role: Follower.into(),
                     status: NodeStatus::Active.into(),
                 },
                 NodeMeta {
                     id: peer3_id,
                     address: "http://127.0.0.1:55002".to_string(),
-                    role: FOLLOWER,
+                    role: Follower.into(),
                     status: NodeStatus::Active.into(),
                 },
             ]
@@ -1856,7 +1860,7 @@ mod handle_raft_request_in_batch_test {
             current_term: 1,
             voted_for: None,
             commit_index: 5,
-            role: LEADER,
+            role: Leader.into(),
         };
         let leader_state_snapshot = LeaderStateSnapshot {
             next_index: HashMap::from([(peer2_id, 6), (peer3_id, 6)]),
@@ -1901,13 +1905,13 @@ mod handle_raft_request_in_batch_test {
                 NodeMeta {
                     id: peer2_id,
                     address: "http://127.0.0.1:55001".to_string(),
-                    role: FOLLOWER,
+                    role: Follower.into(),
                     status: NodeStatus::Active.into(),
                 },
                 NodeMeta {
                     id: peer3_id,
                     address: "http://127.0.0.1:55002".to_string(),
-                    role: FOLLOWER,
+                    role: Follower.into(),
                     status: NodeStatus::Active.into(),
                 },
             ]
@@ -1977,7 +1981,7 @@ mod handle_raft_request_in_batch_test {
             current_term: 1,
             voted_for: None,
             commit_index: 5,
-            role: LEADER,
+            role: Leader.into(),
         };
         let leader_state_snapshot = LeaderStateSnapshot {
             next_index: HashMap::from([(peer2_id, 6), (peer3_id, 6)]),
@@ -2022,13 +2026,13 @@ mod handle_raft_request_in_batch_test {
                 NodeMeta {
                     id: peer2_id,
                     address: "http://127.0.0.1:55001".to_string(),
-                    role: FOLLOWER,
+                    role: Follower.into(),
                     status: NodeStatus::Active.into(),
                 },
                 NodeMeta {
                     id: peer3_id,
                     address: "http://127.0.0.1:55002".to_string(),
-                    role: FOLLOWER,
+                    role: Follower.into(),
                     status: NodeStatus::Active.into(),
                 },
             ]
@@ -2093,7 +2097,7 @@ mod handle_raft_request_in_batch_test {
             current_term: 1,
             voted_for: None,
             commit_index: 5,
-            role: LEADER,
+            role: Leader.into(),
         };
         let leader_state_snapshot = LeaderStateSnapshot {
             next_index: HashMap::from([(peer2_id, 6), (peer3_id, 6)]),
@@ -2196,7 +2200,7 @@ mod handle_raft_request_in_batch_test {
             current_term: 1,
             voted_for: None,
             commit_index: 5,
-            role: LEADER,
+            role: Leader.into(),
         };
         let leader_state_snapshot = LeaderStateSnapshot {
             next_index: HashMap::from([(peer2_id, 6)]),
@@ -2228,7 +2232,7 @@ mod handle_raft_request_in_batch_test {
             vec![NodeMeta {
                 id: peer2_id,
                 address: "http://127.0.0.1:55001".to_string(),
-                role: FOLLOWER,
+                role: Follower.into(),
                 status: NodeStatus::Active.into(),
             }]
         });
@@ -2279,13 +2283,13 @@ mod handle_raft_request_in_batch_test {
                 NodeMeta {
                     id: voter_id,
                     address: "http://127.0.0.1:55001".to_string(),
-                    role: FOLLOWER,
+                    role: Follower.into(),
                     status: NodeStatus::Active.into(),
                 },
                 NodeMeta {
                     id: learner_id,
                     address: "http://127.0.0.1:55002".to_string(),
-                    role: LEARNER,
+                    role: Learner.into(),
                     status: NodeStatus::Joining.into(),
                 },
             ]
@@ -2294,7 +2298,7 @@ mod handle_raft_request_in_batch_test {
             vec![NodeMeta {
                 id: voter_id,
                 address: "http://127.0.0.1:55001".to_string(),
-                role: FOLLOWER,
+                role: Follower.into(),
                 status: NodeStatus::Active.into(),
             }]
         });
@@ -2335,7 +2339,7 @@ mod handle_raft_request_in_batch_test {
             current_term: 1,
             voted_for: None,
             commit_index: 5,
-            role: LEADER,
+            role: Leader.into(),
         };
         let leader_state_snapshot = LeaderStateSnapshot {
             next_index: HashMap::from([(voter_id, 6), (learner_id, 6)]),
@@ -2384,13 +2388,13 @@ mod handle_raft_request_in_batch_test {
                 NodeMeta {
                     id: voter_id,
                     address: "http://127.0.0.1:55001".to_string(),
-                    role: FOLLOWER,
+                    role: Follower.into(),
                     status: NodeStatus::Active.into(),
                 },
                 NodeMeta {
                     id: pending_id,
                     address: "http://127.0.0.1:55002".to_string(),
-                    role: LEARNER,
+                    role: Learner.into(),
                     status: NodeStatus::Syncing.into(),
                 },
             ]
@@ -2399,7 +2403,7 @@ mod handle_raft_request_in_batch_test {
             vec![NodeMeta {
                 id: voter_id,
                 address: "http://127.0.0.1:55001".to_string(),
-                role: FOLLOWER,
+                role: Follower.into(),
                 status: NodeStatus::Active.into(),
             }]
         });
@@ -2440,7 +2444,7 @@ mod handle_raft_request_in_batch_test {
             current_term: 1,
             voted_for: None,
             commit_index: 5,
-            role: LEADER,
+            role: Leader.into(),
         };
         let leader_state_snapshot = LeaderStateSnapshot {
             next_index: HashMap::from([(voter_id, 6), (pending_id, 6)]),
@@ -2488,13 +2492,13 @@ mod handle_raft_request_in_batch_test {
                 NodeMeta {
                     id: learner1,
                     address: "http://127.0.0.1:55001".to_string(),
-                    role: LEARNER,
+                    role: Learner.into(),
                     status: NodeStatus::Joining.into(),
                 },
                 NodeMeta {
                     id: learner2,
                     address: "http://127.0.0.1:55002".to_string(),
-                    role: LEARNER,
+                    role: Learner.into(),
                     status: NodeStatus::Joining.into(),
                 },
             ]
@@ -2537,7 +2541,7 @@ mod handle_raft_request_in_batch_test {
             current_term: 1,
             voted_for: None,
             commit_index: 5,
-            role: LEADER,
+            role: Leader.into(),
         };
         let leader_state_snapshot = LeaderStateSnapshot {
             next_index: HashMap::from([(learner1, 6), (learner2, 6)]),
@@ -2599,7 +2603,7 @@ mod handle_raft_request_in_batch_test {
             current_term: 1,
             voted_for: None,
             commit_index: 1,
-            role: LEADER,
+            role: Leader.into(),
         };
         let leader_state_snapshot = LeaderStateSnapshot {
             next_index: HashMap::new(),
@@ -2642,19 +2646,19 @@ mod handle_raft_request_in_batch_test {
                 NodeMeta {
                     id: voter_id,
                     address: "http://127.0.0.1:55001".to_string(),
-                    role: FOLLOWER,
+                    role: Follower.into(),
                     status: NodeStatus::Active as i32,
                 },
                 NodeMeta {
                     id: joining_id,
                     address: "http://127.0.0.1:55002".to_string(),
-                    role: LEARNER,
+                    role: Learner.into(),
                     status: NodeStatus::Joining as i32,
                 },
                 NodeMeta {
                     id: pending_id,
                     address: "http://127.0.0.1:55003".to_string(),
-                    role: LEARNER,
+                    role: Learner.into(),
                     status: NodeStatus::Syncing as i32,
                 },
             ]
@@ -2663,7 +2667,7 @@ mod handle_raft_request_in_batch_test {
             vec![NodeMeta {
                 id: voter_id,
                 address: "http://127.0.0.1:55001".to_string(),
-                role: FOLLOWER,
+                role: Follower.into(),
                 status: NodeStatus::Active as i32,
             }]
         });
@@ -2709,7 +2713,7 @@ mod handle_raft_request_in_batch_test {
             current_term: 1,
             voted_for: None,
             commit_index: 10,
-            role: LEADER,
+            role: Leader.into(),
         };
         let leader_state_snapshot = LeaderStateSnapshot {
             next_index: HashMap::from([(voter_id, 11), (joining_id, 11), (pending_id, 11)]),
@@ -2755,14 +2759,14 @@ mod handle_raft_request_in_batch_test {
             vec![
                 NodeMeta {
                     id: voter_id,
-                    role: FOLLOWER,
+                    role: Follower.into(),
                     status: NodeStatus::Active.into(),
                     ..Default::default()
                 },
                 NodeMeta {
                     id: pending_id,
                     status: NodeStatus::Joining as i32,
-                    role: LEARNER,
+                    role: Learner.into(),
                     ..Default::default()
                 },
             ]
@@ -2770,7 +2774,7 @@ mod handle_raft_request_in_batch_test {
         membership.expect_voters().returning(move || {
             vec![NodeMeta {
                 id: voter_id,
-                role: FOLLOWER,
+                role: Follower.into(),
                 status: NodeStatus::Active.into(),
                 ..Default::default()
             }]
@@ -2812,7 +2816,7 @@ mod handle_raft_request_in_batch_test {
             current_term: 1,
             voted_for: None,
             commit_index: 5,
-            role: LEADER,
+            role: Leader.into(),
         };
         let leader_state_snapshot = LeaderStateSnapshot {
             next_index: HashMap::from([(2, 6), (3, 6)]),
@@ -2901,7 +2905,7 @@ mod handle_raft_request_in_batch_test {
             current_term: 1,
             voted_for: None,
             commit_index: leader_commit_index,
-            role: LEADER,
+            role: Leader.into(),
         };
         let leader_state_snapshot = LeaderStateSnapshot {
             next_index: HashMap::from([(learner_id, learner_match_index + 1)]),
@@ -2945,7 +2949,7 @@ mod handle_raft_request_in_batch_test {
             vec![NodeMeta {
                 id: learner_id,
                 address: "http://127.0.0.1:55001".to_string(),
-                role: LEARNER,
+                role: Learner.into(),
                 status: NodeStatus::Syncing.into(),
             }]
         });
@@ -2985,7 +2989,7 @@ mod handle_raft_request_in_batch_test {
             current_term: 1,
             voted_for: None,
             commit_index: 1,
-            role: LEADER,
+            role: Leader.into(),
         };
         let leader_state_snapshot = LeaderStateSnapshot {
             next_index: HashMap::from([(learner_id, 1 + 1)]),
diff --git a/d-engine-server/tests/integration_test.rs b/d-engine-server/tests/integration_test.rs
new file mode 100644
index 00000000..fdc19bca
--- /dev/null
+++ b/d-engine-server/tests/integration_test.rs
@@ -0,0 +1,2 @@
+#[cfg(any(test, feature = "test-utils"))]
+mod components;
diff --git a/d-engine/Cargo.toml b/d-engine/Cargo.toml
new file mode 100644
index 00000000..f9e19499
--- /dev/null
+++ b/d-engine/Cargo.toml
@@ -0,0 +1,32 @@
+[package]
+name = "d-engine"
+version = "0.2.0"
+edition = "2024"
+authors = ["Joshua Chi <joshokn@gmail.com>"]
+description = "A lightweight and strongly consistent Raft consensus engine written in Rust. It is a base to build reliable and scalable distributed systems."
+homepage = "https://github.com/deventlab/d-engine"
+repository = "https://github.com/deventlab/d-engine"
+license = "MIT OR Apache-2.0"
+keywords = [
+    "raft",
+    "consensus",
+    "distributed-systems",
+    "storage",
+    "fault-tolerance",
+]
+categories = ["concurrency", "asynchronous", "algorithms", "database"]
+readme = "../README.md"
+
+[package.metadata.docs.rs]
+all-features = true
+rustdoc-args = ["--cfg", "docsrs"]
+
+[features]
+client = ["dep:d-engine-client"]
+server = ["dep:d-engine-server"]
+full = ["client", "server"]
+rocksdb = ["server", "d-engine-server/rocksdb"]
+
+[dependencies]
+d-engine-client = { workspace = true, optional = true }
+d-engine-server = { workspace = true, optional = true }
diff --git a/d-engine/src/lib.rs b/d-engine/src/lib.rs
new file mode 100644
index 00000000..a1a088b0
--- /dev/null
+++ b/d-engine/src/lib.rs
@@ -0,0 +1,192 @@
+//! # d-engine
+//!
+//! A lightweight and strongly consistent Raft consensus engine written in Rust.
+//! Build reliable and scalable distributed systems by embedding d-engine into your applications.
+//!
+//! ## Quick Start
+//!
+//! Add d-engine to your `Cargo.toml` with features you need:
+//!
+//! ```toml
+//! # For client-only applications
+//! d-engine = { version = "0.2", features = ["client"] }
+//!
+//! # For server/embedded applications
+//! d-engine = { version = "0.2", features = ["server"] }
+//!
+//! # For applications that need both
+//! d-engine = { version = "0.2", features = ["full"] }
+//! ```
+//!
+//! ## Features
+//!
+//! - **`client`** - Client library for connecting to d-engine servers
+//! - **`server`** - Embed a d-engine Raft server into your application
+//! - **`full`** - Both client and server capabilities
+//!
+//! ## Client Example
+//!
+//! ```rust,ignore
+//! use d_engine::Client;
+//!
+//! #[tokio::main]
+//! async fn main() -> Result<(), Box<dyn std::error::Error>> {
+//!     let client = Client::builder(vec![
+//!         "http://localhost:9081".into(),
+//!         "http://localhost:9082".into(),
+//!     ])
+//!     .build()
+//!     .await?;
+//!
+//!     // Write data
+//!     client.kv().put("key", "value").await?;
+//!
+//!     // Read data
+//!     let value = client.kv().get("key").await?;
+//!     println!("Value: {:?}", value);
+//!
+//!     Ok(())
+//! }
+//! ```
+//!
+//! ## Server Example (Embedded)
+//!
+//! ```rust,ignore
+//! use d_engine::{NodeBuilder, FileStorageEngine, FileStateMachine};
+//! use std::sync::Arc;
+//! use std::path::PathBuf;
+//!
+//! #[tokio::main]
+//! async fn main() -> Result<(), Box<dyn std::error::Error>> {
+//!     let (tx, rx) = tokio::sync::watch::channel(());
+//!
+//!     let storage = Arc::new(FileStorageEngine::new(PathBuf::from("/tmp/storage"))?);
+//!     let state_machine = Arc::new(FileStateMachine::new(PathBuf::from("/tmp/sm")).await?);
+//!
+//!     let node = NodeBuilder::new(None, rx)
+//!         .storage_engine(storage)
+//!         .state_machine(state_machine)
+//!         .build()
+//!         .start_rpc_server()
+//!         .await
+//!         .ready()?;
+//!
+//!     node.run().await?;
+//!     Ok(())
+//! }
+//! ```
+//!
+//! ## Architecture
+//!
+//! d-engine is designed with a modular architecture:
+//!
+//! - **d-engine-proto**: Protocol definitions (Protobuf/gRPC)
+//! - **d-engine-core**: Core Raft algorithm implementation
+//! - **d-engine-client**: Client library for cluster communication
+//! - **d-engine-server**: Production-ready server runtime
+//!
+//! This main crate re-exports the public APIs from these components based on
+//! enabled features, providing a unified interface for developers.
+
+#![warn(missing_docs)]
+#![cfg_attr(docsrs, feature(doc_cfg))]
+
+// ==================== Client API ====================
+
+#[cfg(feature = "client")]
+#[cfg_attr(docsrs, doc(cfg(feature = "client")))]
+pub use d_engine_client::{
+    // Main entry points
+    Client,
+    // Error types
+    ClientApiError,
+    ClientBuilder,
+    // Configuration
+    ClientConfig,
+    // Specialized clients
+    ClusterClient,
+    KvClient,
+};
+
+#[cfg(feature = "client")]
+#[cfg_attr(docsrs, doc(cfg(feature = "client")))]
+/// Protocol types for client operations
+pub mod protocol {
+    pub use d_engine_client::protocol::{ClientResult, ReadConsistencyPolicy, WriteCommand};
+}
+
+#[cfg(feature = "client")]
+#[cfg_attr(docsrs, doc(cfg(feature = "client")))]
+/// Cluster management types
+pub mod cluster_types {
+    pub use d_engine_client::cluster_types::{NodeMeta, NodeStatus};
+}
+
+// ==================== Server API ====================
+
+#[cfg(feature = "server")]
+#[cfg_attr(docsrs, doc(cfg(feature = "server")))]
+pub use d_engine_server::{
+    // Error types
+    Error,
+    // Storage implementations
+    FileStateMachine,
+    FileStorageEngine,
+    // Data types
+    HardState,
+    // Extension traits for custom implementations
+    LogStore,
+    MetaStore,
+    // Main entry points
+    Node,
+    NodeBuilder,
+    ProstError,
+    Result,
+    SnapshotError,
+    StateMachine,
+    StorageEngine,
+    StorageError,
+};
+
+#[cfg(all(feature = "server", feature = "rocksdb"))]
+#[cfg_attr(docsrs, doc(cfg(all(feature = "server", feature = "rocksdb"))))]
+pub use d_engine_server::{RocksDBStateMachine, RocksDBStorageEngine};
+
+#[cfg(feature = "server")]
+#[cfg_attr(docsrs, doc(cfg(feature = "server")))]
+/// Common Raft protocol types
+pub mod common {
+    pub use d_engine_server::common::{Entry, EntryPayload, LogId, entry_payload};
+}
+
+#[cfg(feature = "server")]
+#[cfg_attr(docsrs, doc(cfg(feature = "server")))]
+/// Client write command types
+pub mod write_command {
+    pub use d_engine_server::client::{WriteCommand, write_command};
+}
+
+#[cfg(feature = "server")]
+#[cfg_attr(docsrs, doc(cfg(feature = "server")))]
+/// Server storage types
+pub mod storage {
+    pub use d_engine_server::server_storage::SnapshotMetadata;
+}
+
+// ==================== Convenience Re-exports ====================
+
+/// Convenient prelude for quick imports
+///
+/// Import everything you need with:
+/// ```rust,ignore
+/// use d_engine::prelude::*;
+/// ```
+pub mod prelude {
+    #[cfg(feature = "client")]
+    pub use d_engine_client::{Client, ClientBuilder};
+
+    #[cfg(feature = "server")]
+    pub use d_engine_server::{
+        FileStateMachine, FileStorageEngine, Node, NodeBuilder, StateMachine, StorageEngine,
+    };
+}
diff --git a/examples/client_usage/Cargo.lock b/examples/client_usage/Cargo.lock
index c9b798f0..7b22f0fc 100644
--- a/examples/client_usage/Cargo.lock
+++ b/examples/client_usage/Cargo.lock
@@ -2,48 +2,21 @@
 # It is not intended for manual editing.
 version = 4
 
-[[package]]
-name = "addr2line"
-version = "0.25.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1b5d307320b3181d6d7954e663bd7c774a838b8220fe0593c86d9fb09f498b4b"
-dependencies = [
- "gimli",
-]
-
 [[package]]
 name = "adler2"
 version = "2.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "320119579fcad9c21884f5c4861d16174d0e06250625266f50fe6898340abefa"
 
-[[package]]
-name = "ahash"
-version = "0.8.12"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5a15f179cd60c4584b8a8c596927aadc462e27f2ca70c04e0071964a73ba7a75"
-dependencies = [
- "cfg-if",
- "once_cell",
- "version_check",
- "zerocopy",
-]
-
 [[package]]
 name = "aho-corasick"
-version = "1.1.3"
+version = "1.1.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8e60d3430d3a69478ad0993f19238d2df97c507009a52b3c10addcd7f6bcb916"
+checksum = "ddd31a130427c27518df266943a5308ed92d4b226cc639f5a8f1002816174301"
 dependencies = [
  "memchr",
 ]
 
-[[package]]
-name = "allocator-api2"
-version = "0.2.21"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "683d7910e743518b0e34f1186f92494becacb047c7b6bf616c96772180fef923"
-
 [[package]]
 name = "anstream"
 version = "0.6.21"
@@ -106,19 +79,6 @@ version = "1.7.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "69f7f8c3906b62b754cd5326047894316021dcfe5a194c8ea52bdd94934a3457"
 
-[[package]]
-name = "async-compression"
-version = "0.4.32"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5a89bce6054c720275ac2432fbba080a66a2106a44a1b804553930ca6909f4e0"
-dependencies = [
- "compression-codecs",
- "compression-core",
- "futures-core",
- "pin-project-lite",
- "tokio",
-]
-
 [[package]]
 name = "async-stream"
 version = "0.3.6"
@@ -222,56 +182,17 @@ dependencies = [
  "tower-service",
 ]
 
-[[package]]
-name = "backtrace"
-version = "0.3.76"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bb531853791a215d7c62a30daf0dde835f381ab5de4589cfe7c649d2cbe92bd6"
-dependencies = [
- "addr2line",
- "cfg-if",
- "libc",
- "miniz_oxide",
- "object",
- "rustc-demangle",
- "windows-link",
-]
-
 [[package]]
 name = "base64"
 version = "0.22.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "72b3254f16251a8381aa12e40e3c4d2f0199f8c6508fbecb9d91f575e0fbb8c6"
 
-[[package]]
-name = "bincode"
-version = "1.3.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b1f45e9417d87227c7a56d22e471c6206462cba514c7590c09aff4cf6d1ddcad"
-dependencies = [
- "serde",
-]
-
-[[package]]
-name = "bitflags"
-version = "1.3.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"
-
 [[package]]
 name = "bitflags"
-version = "2.9.4"
+version = "2.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2261d10cca569e4643e526d8dc2e62e433cc8aba21ab764233731f8d369bf394"
-
-[[package]]
-name = "block-buffer"
-version = "0.10.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3078c7629b62d3f0439517fa394996acacc5cbc91c5a20d8c658e77abd503a71"
-dependencies = [
- "generic-array",
-]
+checksum = "812e12b5285cc515a9c72a5c1d3b6d46a19dac5acfef5265968c166106e31dd3"
 
 [[package]]
 name = "bytes"
@@ -284,9 +205,9 @@ dependencies = [
 
 [[package]]
 name = "cc"
-version = "1.2.41"
+version = "1.2.44"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ac9fe6cdbb24b6ade63616c0a0688e45bb56732262c158df3c0c4bea4ca47cb7"
+checksum = "37521ac7aabe3d13122dc382493e20c9416f299d2ccd5b3a5340a2570cdeb0f3"
 dependencies = [
  "find-msvc-tools",
  "shlex",
@@ -294,15 +215,15 @@ dependencies = [
 
 [[package]]
 name = "cfg-if"
-version = "1.0.3"
+version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2fd1289c04a9ea8cb22300a459a72a385d7c73d3259e2ed7dcb2af674838cfa9"
+checksum = "9330f8b2ff13f34540b44e946ef35111825727b38d33286ef986142615121801"
 
 [[package]]
 name = "clap"
-version = "4.5.49"
+version = "4.5.51"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f4512b90fa68d3a9932cea5184017c5d200f5921df706d45e853537dea51508f"
+checksum = "4c26d721170e0295f191a69bd9a1f93efcdb0aff38684b61ab5750468972e5f5"
 dependencies = [
  "clap_builder",
  "clap_derive",
@@ -310,9 +231,9 @@ dependencies = [
 
 [[package]]
 name = "clap_builder"
-version = "4.5.49"
+version = "4.5.51"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0025e98baa12e766c67ba13ff4695a887a1eba19569aad00a472546795bd6730"
+checksum = "75835f0c7bf681bfd05abe44e965760fea999a5286c6eb2d59883634fd02011a"
 dependencies = [
  "anstream",
  "anstyle",
@@ -344,44 +265,6 @@ version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b05b61dc5112cbb17e4b6cd61790d9845d13888356391624cbe7e41efeac1e75"
 
-[[package]]
-name = "compression-codecs"
-version = "0.4.31"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ef8a506ec4b81c460798f572caead636d57d3d7e940f998160f52bd254bf2d23"
-dependencies = [
- "compression-core",
- "flate2",
- "memchr",
-]
-
-[[package]]
-name = "compression-core"
-version = "0.4.29"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e47641d3deaf41fb1538ac1f54735925e275eaf3bf4d55c81b137fba797e5cbb"
-
-[[package]]
-name = "config"
-version = "0.14.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "68578f196d2a33ff61b27fae256c3164f65e36382648e30666dde05b8cc9dfdf"
-dependencies = [
- "nom",
- "pathdiff",
- "serde",
- "toml",
-]
-
-[[package]]
-name = "cpufeatures"
-version = "0.2.17"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "59ed5838eebb26a2bb2e58f6d5b5316989ae9d08bab10e0e6d103e656d1b0280"
-dependencies = [
- "libc",
-]
-
 [[package]]
 name = "crc32fast"
 version = "1.5.0"
@@ -392,139 +275,45 @@ dependencies = [
 ]
 
 [[package]]
-name = "crossbeam"
-version = "0.8.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1137cd7e7fc0fb5d3c5a8678be38ec56e819125d8d7907411fe24ccb943faca8"
-dependencies = [
- "crossbeam-channel",
- "crossbeam-deque",
- "crossbeam-epoch",
- "crossbeam-queue",
- "crossbeam-utils",
-]
-
-[[package]]
-name = "crossbeam-channel"
-version = "0.5.15"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "82b8f8f868b36967f9606790d1903570de9ceaf870a7bf9fbbd3016d636a2cb2"
-dependencies = [
- "crossbeam-utils",
-]
-
-[[package]]
-name = "crossbeam-deque"
-version = "0.8.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9dd111b7b7f7d55b72c0a6ae361660ee5853c9af73f70c3c2ef6858b950e2e51"
-dependencies = [
- "crossbeam-epoch",
- "crossbeam-utils",
-]
-
-[[package]]
-name = "crossbeam-epoch"
-version = "0.9.18"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5b82ac4a3c2ca9c3460964f020e1402edd5753411d7737aa39c3714ad1b5420e"
-dependencies = [
- "crossbeam-utils",
-]
-
-[[package]]
-name = "crossbeam-queue"
-version = "0.3.12"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0f58bbc28f91df819d0aa2a2c00cd19754769c2fad90579b3592b1c9ba7a3115"
-dependencies = [
- "crossbeam-utils",
-]
-
-[[package]]
-name = "crossbeam-skiplist"
-version = "0.1.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "df29de440c58ca2cc6e587ec3d22347551a32435fbde9d2bff64e78a9ffa151b"
-dependencies = [
- "crossbeam-epoch",
- "crossbeam-utils",
-]
-
-[[package]]
-name = "crossbeam-utils"
-version = "0.8.21"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d0a5c400df2834b80a4c3327b3aad3a4c4cd4de0629063962b03235697506a28"
-
-[[package]]
-name = "crypto-common"
-version = "0.1.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1bfb12502f3fc46cca1bb51ac28df9d618d813cdc3d2f25b9fe775a34af26bb3"
+name = "d-engine"
+version = "0.2.0"
 dependencies = [
- "generic-array",
- "typenum",
+ "d-engine-client",
 ]
 
 [[package]]
-name = "d-engine"
-version = "0.1.3"
+name = "d-engine-client"
+version = "0.2.0"
 dependencies = [
  "arc-swap",
- "async-compression",
- "async-stream",
- "bincode",
  "bytes",
- "config",
- "crc32fast",
- "crossbeam",
- "crossbeam-skiplist",
- "dashmap",
- "flate2",
+ "d-engine-proto",
  "futures",
- "http-body",
- "http-body-util",
- "lru",
- "memmap2",
- "metrics",
- "nanoid",
- "parking_lot",
- "prost",
  "rand",
- "rcgen",
- "ring",
  "serde",
- "sha2",
- "tempfile",
- "thiserror",
  "tokio",
  "tokio-stream",
- "tokio-tar",
- "tokio-util",
  "tonic",
- "tonic-build",
  "tonic-health",
  "tracing",
- "vergen",
 ]
 
 [[package]]
-name = "dashmap"
-version = "5.5.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "978747c1d849a7d2ee5e8adc0159961c48fb7e5db2f06af6723b80123bb53856"
+name = "d-engine-proto"
+version = "0.2.0"
 dependencies = [
- "cfg-if",
- "hashbrown 0.14.5",
- "lock_api",
- "once_cell",
- "parking_lot_core",
+ "bytes",
+ "prost",
+ "serde",
+ "tonic",
+ "tonic-build",
+ "tracing",
+ "vergen",
 ]
 
 [[package]]
 name = "dengine-client-demo"
-version = "0.1.0"
+version = "0.2.0"
 dependencies = [
  "anyhow",
  "clap",
@@ -535,23 +324,13 @@ dependencies = [
 
 [[package]]
 name = "deranged"
-version = "0.5.4"
+version = "0.5.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a41953f86f8a05768a6cda24def994fd2f424b04ec5c719cf89989779f199071"
+checksum = "ececcb659e7ba858fb4f10388c250a7252eb0a27373f1a72b8748afdd248e587"
 dependencies = [
  "powerfmt",
 ]
 
-[[package]]
-name = "digest"
-version = "0.10.7"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9ed9a281f7bc9b7576e61468ba615a66a5c8cfdff42420a70aa82701a3b1e292"
-dependencies = [
- "block-buffer",
- "crypto-common",
-]
-
 [[package]]
 name = "either"
 version = "1.15.0"
@@ -593,18 +372,6 @@ version = "2.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "37909eebbb50d72f9059c3b6d82c0463f2ff062c9e95845c43a6c9c0355411be"
 
-[[package]]
-name = "filetime"
-version = "0.2.26"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bc0505cd1b6fa6580283f6bdf70a73fcf4aba1184038c90902b92b3dd0df63ed"
-dependencies = [
- "cfg-if",
- "libc",
- "libredox",
- "windows-sys 0.60.2",
-]
-
 [[package]]
 name = "find-msvc-tools"
 version = "0.1.4"
@@ -619,12 +386,11 @@ checksum = "1d674e81391d1e1ab681a28d99df07927c6d4aa5b027d7da16ba32d1d21ecd99"
 
 [[package]]
 name = "flate2"
-version = "1.1.4"
+version = "1.1.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dc5a4e564e38c699f2880d3fda590bedc2e69f3f84cd48b457bd892ce61d0aa9"
+checksum = "bfe33edd8e85a12a67454e37f8c75e730830d83e313556ab9ebf9ee7fbeb3bfb"
 dependencies = [
  "crc32fast",
- "libz-sys",
  "miniz_oxide",
 ]
 
@@ -634,12 +400,6 @@ version = "1.0.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3f9eec918d3f24069decb9af1554cad7c880e2da24a9afd88aca000531ab82c1"
 
-[[package]]
-name = "foldhash"
-version = "0.1.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d9c4f5dac5e15c24eb999c26181a6ca40b39fe946cbe4c263c7209467bc83af2"
-
 [[package]]
 name = "futures"
 version = "0.3.31"
@@ -729,16 +489,6 @@ dependencies = [
  "slab",
 ]
 
-[[package]]
-name = "generic-array"
-version = "0.14.9"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4bb6743198531e02858aeaea5398fcc883e71851fcbcb5a2f773e2fb6cb1edf2"
-dependencies = [
- "typenum",
- "version_check",
-]
-
 [[package]]
 name = "getrandom"
 version = "0.2.16"
@@ -747,27 +497,21 @@ checksum = "335ff9f135e4384c8150d6f27c6daed433577f86b4750418338c01a1a2528592"
 dependencies = [
  "cfg-if",
  "libc",
- "wasi 0.11.1+wasi-snapshot-preview1",
+ "wasi",
 ]
 
 [[package]]
 name = "getrandom"
-version = "0.3.3"
+version = "0.3.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "26145e563e54f2cadc477553f1ec5ee650b00862f0a58bcd12cbdc5f0ea2d2f4"
+checksum = "899def5c37c4fd7b2664648c28120ecec138e4d395b459e5ca34f9cce2dd77fd"
 dependencies = [
  "cfg-if",
  "libc",
  "r-efi",
- "wasi 0.14.7+wasi-0.2.4",
+ "wasip2",
 ]
 
-[[package]]
-name = "gimli"
-version = "0.32.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e629b9b98ef3dd8afe6ca2bd0f89306cec16d43d907889945bc5d6687f2f13c7"
-
 [[package]]
 name = "h2"
 version = "0.4.12"
@@ -780,7 +524,7 @@ dependencies = [
  "futures-core",
  "futures-sink",
  "http",
- "indexmap 2.11.4",
+ "indexmap 2.12.0",
  "slab",
  "tokio",
  "tokio-util",
@@ -793,23 +537,6 @@ version = "0.12.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8a9ee70c43aaf417c914396645a0fa852624801b24ebb7ae78fe8272889ac888"
 
-[[package]]
-name = "hashbrown"
-version = "0.14.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e5274423e17b7c9fc20b6e7e208532f9b19825d82dfd615708b70edd83df41f1"
-
-[[package]]
-name = "hashbrown"
-version = "0.15.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9229cfe53dfd69f0609a49f65461bd93001ea1ef889cd5529dd176593f5338a1"
-dependencies = [
- "allocator-api2",
- "equivalent",
- "foldhash",
-]
-
 [[package]]
 name = "hashbrown"
 version = "0.16.0"
@@ -952,30 +679,19 @@ dependencies = [
 
 [[package]]
 name = "indexmap"
-version = "2.11.4"
+version = "2.12.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4b0f83760fb341a774ed326568e19f5a863af4a952def8c39f9ab92fd95b88e5"
+checksum = "6717a8d2a5a929a1a2eb43a12812498ed141a0bcfb7e8f7844fbdbe4303bba9f"
 dependencies = [
  "equivalent",
  "hashbrown 0.16.0",
 ]
 
-[[package]]
-name = "io-uring"
-version = "0.7.10"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "046fa2d4d00aea763528b4950358d0ead425372445dc8ff86312b3c69ff7727b"
-dependencies = [
- "bitflags 2.9.4",
- "cfg-if",
- "libc",
-]
-
 [[package]]
 name = "is_terminal_polyfill"
-version = "1.70.1"
+version = "1.70.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7943c866cc5cd64cbc25b2e01621d07fa8eb2a1a23160ee81ce38704e97b8ecf"
+checksum = "a6cb138bb79a146c1bd460005623e142ef0181e3d0219cb493e02f7d08a35695"
 
 [[package]]
 name = "itertools"
@@ -998,28 +714,6 @@ version = "0.2.177"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2874a2af47a2325c2001a6e6fad9b16a53b802102b528163885171cf92b15976"
 
-[[package]]
-name = "libredox"
-version = "0.1.10"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "416f7e718bdb06000964960ffa43b4335ad4012ae8b99060261aa4a8088d5ccb"
-dependencies = [
- "bitflags 2.9.4",
- "libc",
- "redox_syscall 0.5.18",
-]
-
-[[package]]
-name = "libz-sys"
-version = "1.1.22"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8b70e7a7df205e92a1a4cd9aaae7898dac0aa555503cc0a649494d0d60e7651d"
-dependencies = [
- "cc",
- "pkg-config",
- "vcpkg",
-]
-
 [[package]]
 name = "linux-raw-sys"
 version = "0.11.0"
@@ -1041,15 +735,6 @@ version = "0.4.28"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "34080505efa8e45a4b816c349525ebe327ceaa8559756f0356cba97ef3bf7432"
 
-[[package]]
-name = "lru"
-version = "0.15.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0281c2e25e62316a5c9d98f2d2e9e95a37841afdaf4383c177dbb5c1dfab0568"
-dependencies = [
- "hashbrown 0.15.5",
-]
-
 [[package]]
 name = "matchit"
 version = "0.7.3"
@@ -1062,37 +747,12 @@ version = "2.7.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f52b00d39961fc5b2736ea853c9cc86238e165017a493d1d5c8eac6bdc4cc273"
 
-[[package]]
-name = "memmap2"
-version = "0.9.8"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "843a98750cd611cc2965a8213b53b43e715f13c37a9e096c6408e69990961db7"
-dependencies = [
- "libc",
-]
-
-[[package]]
-name = "metrics"
-version = "0.24.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "25dea7ac8057892855ec285c440160265225438c3c45072613c25a4b26e98ef5"
-dependencies = [
- "ahash",
- "portable-atomic",
-]
-
 [[package]]
 name = "mime"
 version = "0.3.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6877bb514081ee2a7ff5ef9de3281f14a4dd4bceac4c09388074a6b5df8a139a"
 
-[[package]]
-name = "minimal-lexical"
-version = "0.2.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "68354c5c6bd36d73ff3feceb05efa59b6acb7626617f4962be322a825e61f79a"
-
 [[package]]
 name = "miniz_oxide"
 version = "0.8.9"
@@ -1105,13 +765,13 @@ dependencies = [
 
 [[package]]
 name = "mio"
-version = "1.0.4"
+version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "78bed444cc8a2160f01cbcf811ef18cac863ad68ae8ca62092e8db51d51c761c"
+checksum = "69d83b0086dc8ecf3ce9ae2874b2d1290252e2a30720bea58a5c6639b0092873"
 dependencies = [
  "libc",
- "wasi 0.11.1+wasi-snapshot-preview1",
- "windows-sys 0.59.0",
+ "wasi",
+ "windows-sys 0.61.2",
 ]
 
 [[package]]
@@ -1120,25 +780,6 @@ version = "0.10.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1d87ecb2933e8aeadb3e3a02b828fed80a7528047e68b4f424523a0981a3a084"
 
-[[package]]
-name = "nanoid"
-version = "0.4.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3ffa00dec017b5b1a8b7cf5e2c008bfda1aa7e0697ac1508b491fdf2622fb4d8"
-dependencies = [
- "rand",
-]
-
-[[package]]
-name = "nom"
-version = "7.1.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d273983c5a657a70a3e8f2a01329822f3b8c8172b73826411a55751e404a0a4a"
-dependencies = [
- "memchr",
- "minimal-lexical",
-]
-
 [[package]]
 name = "num-conv"
 version = "0.1.0"
@@ -1154,15 +795,6 @@ dependencies = [
  "libc",
 ]
 
-[[package]]
-name = "object"
-version = "0.37.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ff76201f031d8863c38aa7f905eca4f53abbfa15f609db4277d44cd8938f33fe"
-dependencies = [
- "memchr",
-]
-
 [[package]]
 name = "once_cell"
 version = "1.21.3"
@@ -1171,9 +803,9 @@ checksum = "42f5e15c9953c5e4ccceeb2e7382a716482c34515315f7b03532b8b4e8393d2d"
 
 [[package]]
 name = "once_cell_polyfill"
-version = "1.70.1"
+version = "1.70.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a4895175b425cb1f87721b59f0f286c2092bd4af812243672510e1ac53e2e0ad"
+checksum = "384b8ab6d37215f3c5301a95a4accb5d64aa607f1fcb26a11b5303878451b4fe"
 
 [[package]]
 name = "parking_lot"
@@ -1193,27 +825,11 @@ checksum = "2621685985a2ebf1c516881c026032ac7deafcda1a2c9b7850dc81e3dfcb64c1"
 dependencies = [
  "cfg-if",
  "libc",
- "redox_syscall 0.5.18",
+ "redox_syscall",
  "smallvec",
  "windows-link",
 ]
 
-[[package]]
-name = "pathdiff"
-version = "0.2.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "df94ce210e5bc13cb6651479fa48d14f601d9858cfe0467f43ae157023b938d3"
-
-[[package]]
-name = "pem"
-version = "3.0.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1d30c53c26bc5b31a98cd02d20f25a7c8567146caf63ed593a9d87b2775291be"
-dependencies = [
- "base64",
- "serde_core",
-]
-
 [[package]]
 name = "percent-encoding"
 version = "2.3.2"
@@ -1227,7 +843,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3672b37090dbd86368a4145bc067582552b29c27377cad4e0a306c97f9bd7772"
 dependencies = [
  "fixedbitset",
- "indexmap 2.11.4",
+ "indexmap 2.12.0",
 ]
 
 [[package]]
@@ -1262,18 +878,6 @@ version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8b870d8c151b6f2fb93e84a13146138f05d02ed11c7e7c54f8826aaaf7c9f184"
 
-[[package]]
-name = "pkg-config"
-version = "0.3.32"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7edddbd0b52d732b21ad9a5fab5c704c14cd949e5e9a1ec5929a24fded1b904c"
-
-[[package]]
-name = "portable-atomic"
-version = "1.11.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f84267b20a16ea918e43c6a88433c2d54fa145c92a811b5b047ccbe153674483"
-
 [[package]]
 name = "powerfmt"
 version = "0.2.0"
@@ -1301,9 +905,9 @@ dependencies = [
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.101"
+version = "1.0.103"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "89ae43fd86e4158d6db51ad8e2b80f313af9cc74f5c0e03ccb87de09998732de"
+checksum = "5ee95bc4ef87b8d5ba32e8b7714ccc834865276eab0aed5c9958d00ec45f49e8"
 dependencies = [
  "unicode-ident",
 ]
@@ -1405,35 +1009,13 @@ dependencies = [
  "getrandom 0.2.16",
 ]
 
-[[package]]
-name = "rcgen"
-version = "0.13.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "75e669e5202259b5314d1ea5397316ad400819437857b90861765f24c4cf80a2"
-dependencies = [
- "pem",
- "ring",
- "rustls-pki-types",
- "time",
- "yasna",
-]
-
-[[package]]
-name = "redox_syscall"
-version = "0.3.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "567664f262709473930a4bf9e51bf2ebf3348f2e748ccc50dea20646858f8f29"
-dependencies = [
- "bitflags 1.3.2",
-]
-
 [[package]]
 name = "redox_syscall"
 version = "0.5.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ed2bf2547551a7053d6fdfafda3f938979645c44812fbfcda098faae3f1a362d"
 dependencies = [
- "bitflags 2.9.4",
+ "bitflags",
 ]
 
 [[package]]
@@ -1479,19 +1061,13 @@ dependencies = [
  "windows-sys 0.52.0",
 ]
 
-[[package]]
-name = "rustc-demangle"
-version = "0.1.26"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "56f7d92ca342cea22a06f2121d944b4fd82af56988c270852495420f961d4ace"
-
 [[package]]
 name = "rustix"
 version = "1.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cd15f8a2c5551a84d56efdc1cd049089e409ac19a3072d5037a17fd70719ff3e"
 dependencies = [
- "bitflags 2.9.4",
+ "bitflags",
  "errno",
  "libc",
  "linux-raw-sys",
@@ -1500,9 +1076,9 @@ dependencies = [
 
 [[package]]
 name = "rustls"
-version = "0.23.32"
+version = "0.23.34"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cd3c25631629d034ce7cd9940adc9d45762d46de2b0f57193c4443b92c6d4d40"
+checksum = "6a9586e9ee2b4f8fab52a0048ca7334d7024eef48e2cb9407e3497bb7cab7fa7"
 dependencies = [
  "log",
  "once_cell",
@@ -1524,18 +1100,18 @@ dependencies = [
 
 [[package]]
 name = "rustls-pki-types"
-version = "1.12.0"
+version = "1.13.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "229a4a4c221013e7e1f1a043678c5cc39fe5171437c88fb47151a21e6f5b5c79"
+checksum = "94182ad936a0c91c324cd46c6511b9510ed16af436d7b5bab34beab0afd55f7a"
 dependencies = [
  "zeroize",
 ]
 
 [[package]]
 name = "rustls-webpki"
-version = "0.103.7"
+version = "0.103.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e10b3f4191e8a80e6b43eebabfac91e5dcecebb27a71f04e820c47ec41d314bf"
+checksum = "2ffdfa2f5286e2247234e03f680868ac2815974dc39e00ea15adc445d0aafe52"
 dependencies = [
  "ring",
  "rustls-pki-types",
@@ -1584,26 +1160,6 @@ dependencies = [
  "syn",
 ]
 
-[[package]]
-name = "serde_spanned"
-version = "0.6.9"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bf41e0cfaf7226dca15e8197172c295a782857fcb97fad1808a166870dee75a3"
-dependencies = [
- "serde",
-]
-
-[[package]]
-name = "sha2"
-version = "0.10.9"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a7507d819769d01a365ab707794a4084392c824f54a7a6a7862f8c3d0892b283"
-dependencies = [
- "cfg-if",
- "cpufeatures",
- "digest",
-]
-
 [[package]]
 name = "shlex"
 version = "1.3.0"
@@ -1671,9 +1227,9 @@ checksum = "13c2bddecc57b384dee18652358fb23172facb8a2c51ccc10d74c157bdea3292"
 
 [[package]]
 name = "syn"
-version = "2.0.106"
+version = "2.0.108"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ede7c438028d4436d71104916910f5bb611972c5cfd7f89b8300a8186e6fada6"
+checksum = "da58917d35242480a05c2897064da0a80589a2a0476c9a3f2fdc83b53502e917"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -1693,7 +1249,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2d31c77bdf42a745371d260a26ca7163f1e0924b64afa0b688e61b5a9fa02f16"
 dependencies = [
  "fastrand",
- "getrandom 0.3.3",
+ "getrandom 0.3.4",
  "once_cell",
  "rustix",
  "windows-sys 0.61.2",
@@ -1708,26 +1264,6 @@ dependencies = [
  "winapi-util",
 ]
 
-[[package]]
-name = "thiserror"
-version = "1.0.69"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b6aaf5339b578ea85b50e080feb250a3e8ae8cfcdff9a461c9ec2904bc923f52"
-dependencies = [
- "thiserror-impl",
-]
-
-[[package]]
-name = "thiserror-impl"
-version = "1.0.69"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4fee6c4efc90059e10f81e6d42c60a18f76588c3d74cb83a0b242a2b6c7504c1"
-dependencies = [
- "proc-macro2",
- "quote",
- "syn",
-]
-
 [[package]]
 name = "time"
 version = "0.3.44"
@@ -1763,29 +1299,26 @@ dependencies = [
 
 [[package]]
 name = "tokio"
-version = "1.47.1"
+version = "1.48.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "89e49afdadebb872d3145a5638b59eb0691ea23e46ca484037cfab3b76b95038"
+checksum = "ff360e02eab121e0bc37a2d3b4d4dc622e6eda3a8e5253d5435ecf5bd4c68408"
 dependencies = [
- "backtrace",
  "bytes",
- "io-uring",
  "libc",
  "mio",
  "parking_lot",
  "pin-project-lite",
  "signal-hook-registry",
- "slab",
  "socket2 0.6.1",
  "tokio-macros",
- "windows-sys 0.59.0",
+ "windows-sys 0.61.2",
 ]
 
 [[package]]
 name = "tokio-macros"
-version = "2.5.0"
+version = "2.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6e06d43f1345a3bcd39f6a56dbb7dcab2ba47e68e8ac134855e7e2bdbaf8cab8"
+checksum = "af407857209536a95c8e56f8231ef2c2e2aff839b22e07a1ffcbc617e9db9fa5"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -1813,21 +1346,6 @@ dependencies = [
  "tokio",
 ]
 
-[[package]]
-name = "tokio-tar"
-version = "0.3.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9d5714c010ca3e5c27114c1cdeb9d14641ace49874aa5626d7149e47aedace75"
-dependencies = [
- "filetime",
- "futures-core",
- "libc",
- "redox_syscall 0.3.5",
- "tokio",
- "tokio-stream",
- "xattr",
-]
-
 [[package]]
 name = "tokio-util"
 version = "0.7.16"
@@ -1841,47 +1359,6 @@ dependencies = [
  "tokio",
 ]
 
-[[package]]
-name = "toml"
-version = "0.8.23"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dc1beb996b9d83529a9e75c17a1686767d148d70663143c7854d8b4a09ced362"
-dependencies = [
- "serde",
- "serde_spanned",
- "toml_datetime",
- "toml_edit",
-]
-
-[[package]]
-name = "toml_datetime"
-version = "0.6.11"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "22cddaf88f4fbc13c51aebbf5f8eceb5c7c5a9da2ac40a13519eb5b0a0e8f11c"
-dependencies = [
- "serde",
-]
-
-[[package]]
-name = "toml_edit"
-version = "0.22.27"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "41fe8c660ae4257887cf66394862d21dbca4a6ddd26f04a3560410406a2f819a"
-dependencies = [
- "indexmap 2.11.4",
- "serde",
- "serde_spanned",
- "toml_datetime",
- "toml_write",
- "winnow",
-]
-
-[[package]]
-name = "toml_write"
-version = "0.1.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5d99f8c9a7727884afe522e9bd5edbfc91a3312b36a77b5fb8926e4c31a41801"
-
 [[package]]
 name = "tonic"
 version = "0.12.3"
@@ -2025,17 +1502,11 @@ version = "0.2.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e421abadd41a4225275504ea4d6566923418b7f05506fbc9c0fe86ba7396114b"
 
-[[package]]
-name = "typenum"
-version = "1.19.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "562d481066bde0658276a35467c4af00bdc6ee726305698a55b86e61d7ad82bb"
-
 [[package]]
 name = "unicode-ident"
-version = "1.0.19"
+version = "1.0.22"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f63a545481291138910575129486daeaf8ac54aee4387fe7906919f7830c7d9d"
+checksum = "9312f7c4f6ff9069b165498234ce8be658059c6728633667c526e27dc2cf1df5"
 
 [[package]]
 name = "untrusted"
@@ -2049,12 +1520,6 @@ version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "06abde3611657adf66d383f00b093d7faecc7fa57071cce2578660c9f1010821"
 
-[[package]]
-name = "vcpkg"
-version = "0.2.15"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "accd4ea62f7bb7a82fe23066fb0957d48ef677f6eeb8215f372f52e48bb32426"
-
 [[package]]
 name = "vergen"
 version = "8.3.2"
@@ -2067,12 +1532,6 @@ dependencies = [
  "time",
 ]
 
-[[package]]
-name = "version_check"
-version = "0.9.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0b928f33d975fc6ad9f86c8f283853ad26bdd5b10b7f1542aa2fa15e2289105a"
-
 [[package]]
 name = "want"
 version = "0.3.1"
@@ -2088,15 +1547,6 @@ version = "0.11.1+wasi-snapshot-preview1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ccf3ec651a847eb01de73ccad15eb7d99f80485de043efb2f370cd654f4ea44b"
 
-[[package]]
-name = "wasi"
-version = "0.14.7+wasi-0.2.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "883478de20367e224c0090af9cf5f9fa85bed63a95c1abf3afc5c083ebc06e8c"
-dependencies = [
- "wasip2",
-]
-
 [[package]]
 name = "wasip2"
 version = "1.0.1+wasi-0.2.4"
@@ -2152,15 +1602,6 @@ dependencies = [
  "windows-targets 0.52.6",
 ]
 
-[[package]]
-name = "windows-sys"
-version = "0.59.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1e38bc4d79ed67fd075bcc251a1c39b32a1776bbe92e5bef1f0bf1f8c531853b"
-dependencies = [
- "windows-targets 0.52.6",
-]
-
 [[package]]
 name = "windows-sys"
 version = "0.60.2"
@@ -2308,40 +1749,12 @@ version = "0.53.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d6bbff5f0aada427a1e5a6da5f1f98158182f26556f345ac9e04d36d0ebed650"
 
-[[package]]
-name = "winnow"
-version = "0.7.13"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "21a0236b59786fed61e2a80582dd500fe61f18b5dca67a4a067d0bc9039339cf"
-dependencies = [
- "memchr",
-]
-
 [[package]]
 name = "wit-bindgen"
 version = "0.46.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f17a85883d4e6d00e8a97c586de764dabcc06133f7f1d55dce5cdc070ad7fe59"
 
-[[package]]
-name = "xattr"
-version = "1.6.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "32e45ad4206f6d2479085147f02bc2ef834ac85886624a23575ae137c8aa8156"
-dependencies = [
- "libc",
- "rustix",
-]
-
-[[package]]
-name = "yasna"
-version = "0.5.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e17bb3549cc1321ae1296b9cdc2698e2b6cb1992adfa19a8c72e5b7a738f44cd"
-dependencies = [
- "time",
-]
-
 [[package]]
 name = "zerocopy"
 version = "0.8.27"
diff --git a/examples/client_usage/Cargo.toml b/examples/client_usage/Cargo.toml
index ec34d894..9e09b914 100644
--- a/examples/client_usage/Cargo.toml
+++ b/examples/client_usage/Cargo.toml
@@ -1,10 +1,10 @@
 [package]
 name = "dengine-client-demo"
-version = "0.1.0"
+version = "0.2.0"
 edition = "2021"
 
 [dependencies]
-d-engine = { path = "../../../d-engine" }
+d-engine = { path = "../../d-engine", features = ["client"] }
 
 clap = { version = "4.0", features = ["derive"] }
 tokio = { version = "1.36.0", features = ["full"] }
diff --git a/examples/client_usage/src/main.rs b/examples/client_usage/src/main.rs
index 398cd230..d452e5af 100644
--- a/examples/client_usage/src/main.rs
+++ b/examples/client_usage/src/main.rs
@@ -1,13 +1,11 @@
 use anyhow::Result;
 use clap::Parser;
 use clap::Subcommand;
-use d_engine::client::ClientApiError;
-use d_engine::config::ReadConsistencyPolicy;
-use d_engine::proto::client::ClientResult;
-use d_engine::proto::cluster::NodeMeta;
-use d_engine::proto::common::NodeStatus;
-use d_engine::ClientBuilder;
-use d_engine::ConvertError;
+use d_engine::{
+    cluster_types::{NodeMeta, NodeStatus},
+    protocol::{ClientResult, ReadConsistencyPolicy},
+    Client, ClientApiError, ClientBuilder,
+};
 
 #[derive(Parser)]
 #[command(version, about, long_about = None)]
@@ -73,7 +71,7 @@ async fn main() -> Result<()> {
 }
 
 async fn handle_write(
-    client: &d_engine::Client,
+    client: &Client,
     key: u64,
     value: u64,
 ) -> Result<()> {
@@ -87,7 +85,7 @@ async fn handle_write(
 }
 
 async fn handle_delete(
-    client: &d_engine::Client,
+    client: &Client,
     key: u64,
 ) -> Result<()> {
     println!("Deleting key({key})");
@@ -100,7 +98,7 @@ async fn handle_delete(
 }
 
 async fn handle_read(
-    client: &d_engine::Client,
+    client: &Client,
     key: u64,
     consistency: &str,
 ) -> Result<()> {
@@ -129,7 +127,7 @@ async fn handle_read(
 }
 
 async fn handle_cluster_command(
-    client: &d_engine::Client,
+    client: &Client,
     node_id: u32,
     address: String,
 ) -> crate::Result<()> {
@@ -160,7 +158,11 @@ pub fn safe_vk<K: AsRef<[u8]>>(bytes: K) -> crate::Result<u64> {
     let expected_len = 8;
 
     if bytes.len() != expected_len {
-        return Err(ConvertError::InvalidLength(bytes.len()).into());
+        return Err(anyhow::anyhow!(
+            "Invalid length for value key conversion: expected {}, got {}",
+            expected_len,
+            bytes.len()
+        ));
     }
     let array: [u8; 8] = bytes.try_into().expect("Guaranteed safe after length check");
     Ok(u64::from_be_bytes(array))
@@ -170,7 +172,7 @@ pub fn safe_vk<K: AsRef<[u8]>>(bytes: K) -> crate::Result<u64> {
 ///
 /// # Examples
 /// ```
-/// use d_engine::convert::safe_kv;
+/// use convert::safe_kv;
 ///
 /// let bytes = safe_kv(0x1234_5678_9ABC_DEF0);
 /// assert_eq!(bytes, [0x12, 0x34, 0x56, 0x78, 0x9A, 0xBC, 0xDE, 0xF0]);
diff --git a/examples/rocksdb-cluster/Cargo.lock b/examples/rocksdb-cluster/Cargo.lock
index c14129e4..a9f4d428 100644
--- a/examples/rocksdb-cluster/Cargo.lock
+++ b/examples/rocksdb-cluster/Cargo.lock
@@ -2,15 +2,6 @@
 # It is not intended for manual editing.
 version = 4
 
-[[package]]
-name = "addr2line"
-version = "0.24.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dfbe277e56a376000877090da837660b4427aad530e3028d44e0bffe4f89a1c1"
-dependencies = [
- "gimli",
-]
-
 [[package]]
 name = "adler2"
 version = "2.0.1"
@@ -31,9 +22,9 @@ dependencies = [
 
 [[package]]
 name = "aho-corasick"
-version = "1.1.3"
+version = "1.1.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8e60d3430d3a69478ad0993f19238d2df97c507009a52b3c10addcd7f6bcb916"
+checksum = "ddd31a130427c27518df266943a5308ed92d4b226cc639f5a8f1002816174301"
 dependencies = [
  "memchr",
 ]
@@ -46,9 +37,9 @@ checksum = "683d7910e743518b0e34f1186f92494becacb047c7b6bf616c96772180fef923"
 
 [[package]]
 name = "anyhow"
-version = "1.0.99"
+version = "1.0.100"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b0674a1ddeecb70197781e945de4b3b8ffb61fa939a5597bcf48503737663100"
+checksum = "a23eb6b1614318a8071c9b2521f36b424b2c83db5eb3a0fead4a6c0809af6e61"
 
 [[package]]
 name = "arc-swap"
@@ -58,15 +49,13 @@ checksum = "69f7f8c3906b62b754cd5326047894316021dcfe5a194c8ea52bdd94934a3457"
 
 [[package]]
 name = "async-compression"
-version = "0.4.28"
+version = "0.4.32"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6448dfb3960f0b038e88c781ead1e7eb7929dfc3a71a1336ec9086c00f6d1e75"
+checksum = "5a89bce6054c720275ac2432fbba080a66a2106a44a1b804553930ca6909f4e0"
 dependencies = [
  "compression-codecs",
  "compression-core",
- "flate2",
  "futures-core",
- "memchr",
  "pin-project-lite",
  "tokio",
 ]
@@ -118,9 +107,9 @@ checksum = "c08606f8c3cbf4ce6ec8e28fb0014a2c086708fe954eaa885384a6165172e7e8"
 
 [[package]]
 name = "aws-lc-rs"
-version = "1.13.3"
+version = "1.14.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5c953fe1ba023e6b7730c0d4b031d06f267f23a46167dcbd40316644b10a17ba"
+checksum = "879b6c89592deb404ba4dc0ae6b58ffd1795c78991cbb5b8bc441c48a070440d"
 dependencies = [
  "aws-lc-sys",
  "zeroize",
@@ -128,11 +117,11 @@ dependencies = [
 
 [[package]]
 name = "aws-lc-sys"
-version = "0.30.0"
+version = "0.32.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dbfd150b5dbdb988bcc8fb1fe787eb6b7ee6180ca24da683b61ea5405f3d43ff"
+checksum = "107a4e9d9cab9963e04e84bb8dee0e25f2a987f9a8bad5ed054abd439caa8f8c"
 dependencies = [
- "bindgen 0.69.5",
+ "bindgen",
  "cc",
  "cmake",
  "dunce",
@@ -186,21 +175,6 @@ dependencies = [
  "tower-service",
 ]
 
-[[package]]
-name = "backtrace"
-version = "0.3.75"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6806a6321ec58106fea15becdad98371e28d92ccbc7c8f1b3b6dd724fe8f1002"
-dependencies = [
- "addr2line",
- "cfg-if",
- "libc",
- "miniz_oxide",
- "object",
- "rustc-demangle",
- "windows-targets 0.52.6",
-]
-
 [[package]]
 name = "base64"
 version = "0.22.1"
@@ -236,43 +210,22 @@ dependencies = [
  "virtue",
 ]
 
-[[package]]
-name = "bindgen"
-version = "0.69.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "271383c67ccabffb7381723dea0672a673f292304fcb45c01cc648c7a8d58088"
-dependencies = [
- "bitflags 2.9.3",
- "cexpr",
- "clang-sys",
- "itertools 0.12.1",
- "lazy_static",
- "lazycell",
- "log",
- "prettyplease",
- "proc-macro2",
- "quote",
- "regex",
- "rustc-hash 1.1.0",
- "shlex",
- "syn",
- "which",
-]
-
 [[package]]
 name = "bindgen"
 version = "0.72.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "993776b509cfb49c750f11b8f07a46fa23e0a1386ffc01fb1e7d343efc387895"
 dependencies = [
- "bitflags 2.9.3",
+ "bitflags 2.10.0",
  "cexpr",
  "clang-sys",
- "itertools 0.12.1",
+ "itertools 0.13.0",
+ "log",
+ "prettyplease",
  "proc-macro2",
  "quote",
  "regex",
- "rustc-hash 2.1.1",
+ "rustc-hash",
  "shlex",
  "syn",
 ]
@@ -285,9 +238,9 @@ checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"
 
 [[package]]
 name = "bitflags"
-version = "2.9.3"
+version = "2.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "34efbcccd345379ca2868b2b2c9d3782e9cc58ba87bc7d79d5b53d9c9ae6f25d"
+checksum = "812e12b5285cc515a9c72a5c1d3b6d46a19dac5acfef5265968c166106e31dd3"
 
 [[package]]
 name = "block-buffer"
@@ -325,10 +278,11 @@ dependencies = [
 
 [[package]]
 name = "cc"
-version = "1.2.34"
+version = "1.2.44"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "42bc4aea80032b7bf409b0bc7ccad88853858911b7713a8062fdc0623867bedc"
+checksum = "37521ac7aabe3d13122dc382493e20c9416f299d2ccd5b3a5340a2570cdeb0f3"
 dependencies = [
+ "find-msvc-tools",
  "jobserver",
  "libc",
  "shlex",
@@ -345,9 +299,9 @@ dependencies = [
 
 [[package]]
 name = "cfg-if"
-version = "1.0.3"
+version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2fd1289c04a9ea8cb22300a459a72a385d7c73d3259e2ed7dcb2af674838cfa9"
+checksum = "9330f8b2ff13f34540b44e946ef35111825727b38d33286ef986142615121801"
 
 [[package]]
 name = "clang-sys"
@@ -371,22 +325,20 @@ dependencies = [
 
 [[package]]
 name = "compression-codecs"
-version = "0.4.28"
+version = "0.4.31"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "46cc6539bf1c592cff488b9f253b30bc0ec50d15407c2cf45e27bd8f308d5905"
+checksum = "ef8a506ec4b81c460798f572caead636d57d3d7e940f998160f52bd254bf2d23"
 dependencies = [
  "compression-core",
  "flate2",
- "futures-core",
  "memchr",
- "pin-project-lite",
 ]
 
 [[package]]
 name = "compression-core"
-version = "0.4.28"
+version = "0.4.29"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2957e823c15bde7ecf1e8b64e537aa03a6be5fda0e2334e99887669e75b12e01"
+checksum = "e47641d3deaf41fb1538ac1f54735925e275eaf3bf4d55c81b137fba797e5cbb"
 
 [[package]]
 name = "config"
@@ -512,9 +464,15 @@ dependencies = [
 
 [[package]]
 name = "d-engine"
-version = "0.1.3"
+version = "0.2.0"
+dependencies = [
+ "d-engine-server",
+]
+
+[[package]]
+name = "d-engine-core"
+version = "0.1.0"
 dependencies = [
- "arc-swap",
  "async-compression",
  "async-stream",
  "bincode 1.3.3",
@@ -523,8 +481,8 @@ dependencies = [
  "crc32fast",
  "crossbeam",
  "crossbeam-skiplist",
+ "d-engine-proto",
  "dashmap",
- "flate2",
  "futures",
  "http-body",
  "http-body-util",
@@ -532,12 +490,8 @@ dependencies = [
  "memmap2",
  "metrics",
  "nanoid",
- "parking_lot",
  "prost",
  "rand 0.8.5",
- "rcgen",
- "ring",
- "rocksdb",
  "serde",
  "sha2",
  "tempfile",
@@ -545,14 +499,55 @@ dependencies = [
  "tokio",
  "tokio-stream",
  "tokio-tar",
- "tokio-util",
+ "tonic",
+ "tracing",
+]
+
+[[package]]
+name = "d-engine-proto"
+version = "0.2.0"
+dependencies = [
+ "bytes",
+ "prost",
+ "serde",
  "tonic",
  "tonic-build",
- "tonic-health",
  "tracing",
  "vergen",
 ]
 
+[[package]]
+name = "d-engine-server"
+version = "0.2.0"
+dependencies = [
+ "arc-swap",
+ "bincode 1.3.3",
+ "bytes",
+ "config",
+ "crc32fast",
+ "crossbeam",
+ "crossbeam-skiplist",
+ "d-engine-core",
+ "d-engine-proto",
+ "dashmap",
+ "futures",
+ "http-body",
+ "http-body-util",
+ "metrics",
+ "parking_lot",
+ "prost",
+ "rcgen",
+ "rocksdb",
+ "serde",
+ "tempfile",
+ "tokio",
+ "tokio-stream",
+ "tokio-util",
+ "tonic",
+ "tonic-health",
+ "tracing",
+]
+
 [[package]]
 name = "dashmap"
 version = "5.5.3"
@@ -568,9 +563,9 @@ dependencies = [
 
 [[package]]
 name = "deranged"
-version = "0.4.0"
+version = "0.5.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9c9e6a11ca8224451684bc0d7d5a7adbf8f2fd6887261a1cfc3c0432f9d4068e"
+checksum = "ececcb659e7ba858fb4f10388c250a7252eb0a27373f1a72b8748afdd248e587"
 dependencies = [
  "powerfmt",
 ]
@@ -605,12 +600,12 @@ checksum = "877a4ace8713b0bcf2a4e7eec82529c029f1d0619886d18145fea96c3ffe5c0f"
 
 [[package]]
 name = "errno"
-version = "0.3.13"
+version = "0.3.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "778e2ac28f6c47af28e4907f13ffd1e1ddbd400980a9abd7c8df189bf578a5ad"
+checksum = "39cab71617ae0d63f51a36d69f866391735b51691dbda63cf6f96d042b63efeb"
 dependencies = [
  "libc",
- "windows-sys 0.60.2",
+ "windows-sys 0.61.2",
 ]
 
 [[package]]
@@ -631,6 +626,12 @@ dependencies = [
  "windows-sys 0.60.2",
 ]
 
+[[package]]
+name = "find-msvc-tools"
+version = "0.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "52051878f80a721bb68ebfbc930e07b65ba72f2da88968ea5c06fd6ca3d3a127"
+
 [[package]]
 name = "fixedbitset"
 version = "0.5.7"
@@ -639,12 +640,11 @@ checksum = "1d674e81391d1e1ab681a28d99df07927c6d4aa5b027d7da16ba32d1d21ecd99"
 
 [[package]]
 name = "flate2"
-version = "1.1.2"
+version = "1.1.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4a3d7db9596fecd151c5f638c0ee5d5bd487b6e0ea232e5dc96d5250f6f94b1d"
+checksum = "bfe33edd8e85a12a67454e37f8c75e730830d83e313556ab9ebf9ee7fbeb3bfb"
 dependencies = [
  "crc32fast",
- "libz-sys",
  "miniz_oxide",
 ]
 
@@ -757,9 +757,9 @@ dependencies = [
 
 [[package]]
 name = "generic-array"
-version = "0.14.7"
+version = "0.14.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "85649ca51fd72272d7821adaf274ad91c288277713d9c18820d8499a7ff69e9a"
+checksum = "4bb6743198531e02858aeaea5398fcc883e71851fcbcb5a2f773e2fb6cb1edf2"
 dependencies = [
  "typenum",
  "version_check",
@@ -773,27 +773,21 @@ checksum = "335ff9f135e4384c8150d6f27c6daed433577f86b4750418338c01a1a2528592"
 dependencies = [
  "cfg-if",
  "libc",
- "wasi 0.11.1+wasi-snapshot-preview1",
+ "wasi",
 ]
 
 [[package]]
 name = "getrandom"
-version = "0.3.3"
+version = "0.3.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "26145e563e54f2cadc477553f1ec5ee650b00862f0a58bcd12cbdc5f0ea2d2f4"
+checksum = "899def5c37c4fd7b2664648c28120ecec138e4d395b459e5ca34f9cce2dd77fd"
 dependencies = [
  "cfg-if",
  "libc",
  "r-efi",
- "wasi 0.14.2+wasi-0.2.4",
+ "wasip2",
 ]
 
-[[package]]
-name = "gimli"
-version = "0.31.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "07e28edb80900c19c28f1072f2e8aeca7fa06b23cd4169cefe1af5aa3260783f"
-
 [[package]]
 name = "glob"
 version = "0.3.3"
@@ -812,7 +806,7 @@ dependencies = [
  "futures-core",
  "futures-sink",
  "http",
- "indexmap 2.11.0",
+ "indexmap 2.12.0",
  "slab",
  "tokio",
  "tokio-util",
@@ -843,19 +837,16 @@ dependencies = [
 ]
 
 [[package]]
-name = "heck"
-version = "0.5.0"
+name = "hashbrown"
+version = "0.16.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2304e00983f87ffb38b55b444b5e3b60a884b5d30c0fca7d82fe33449bbe55ea"
+checksum = "5419bdc4f6a9207fbeba6d11b604d481addf78ecd10c11ad51e76c2f6482748d"
 
 [[package]]
-name = "home"
-version = "0.5.11"
+name = "heck"
+version = "0.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "589533453244b0995c858700322199b2becb13b627df2851f64a2775d024abcf"
-dependencies = [
- "windows-sys 0.59.0",
-]
+checksum = "2304e00983f87ffb38b55b444b5e3b60a884b5d30c0fca7d82fe33449bbe55ea"
 
 [[package]]
 name = "http"
@@ -958,9 +949,9 @@ dependencies = [
 
 [[package]]
 name = "hyper-util"
-version = "0.1.16"
+version = "0.1.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8d9b05277c7e8da2c93a568989bb6207bef0112e8d17df7a6eda4a3cf143bc5e"
+checksum = "3c6995591a8f1380fcb4ba966a252a4b29188d51d2b89e3a252f5305be65aea8"
 dependencies = [
  "bytes",
  "futures-channel",
@@ -971,7 +962,7 @@ dependencies = [
  "hyper",
  "libc",
  "pin-project-lite",
- "socket2 0.6.0",
+ "socket2 0.6.1",
  "tokio",
  "tower-service",
  "tracing",
@@ -989,23 +980,12 @@ dependencies = [
 
 [[package]]
 name = "indexmap"
-version = "2.11.0"
+version = "2.12.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f2481980430f9f78649238835720ddccc57e52df14ffce1c6f37391d61b563e9"
+checksum = "6717a8d2a5a929a1a2eb43a12812498ed141a0bcfb7e8f7844fbdbe4303bba9f"
 dependencies = [
  "equivalent",
- "hashbrown 0.15.5",
-]
-
-[[package]]
-name = "io-uring"
-version = "0.7.10"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "046fa2d4d00aea763528b4950358d0ead425372445dc8ff86312b3c69ff7727b"
-dependencies = [
- "bitflags 2.9.3",
- "cfg-if",
- "libc",
+ "hashbrown 0.16.0",
 ]
 
 [[package]]
@@ -1016,9 +996,9 @@ checksum = "469fb0b9cefa57e3ef31275ee7cacb78f2fdca44e4765491884a2b119d4eb130"
 
 [[package]]
 name = "itertools"
-version = "0.12.1"
+version = "0.13.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ba291022dbbd398a455acf126c1e341954079855bc60dfdda641363bd6922569"
+checksum = "413ee7dfc52ee1a4949ceeb7dbc8a33f2d6c088194d9f922fb8318faf1f01186"
 dependencies = [
  "either",
 ]
@@ -1044,15 +1024,15 @@ version = "0.1.34"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9afb3de4395d6b3e67a780b6de64b51c978ecf11cb9a462c66be7d4ca9039d33"
 dependencies = [
- "getrandom 0.3.3",
+ "getrandom 0.3.4",
  "libc",
 ]
 
 [[package]]
 name = "js-sys"
-version = "0.3.77"
+version = "0.3.82"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1cfaf33c695fc6e08064efbc1f72ec937429614f25eef83af942d0e227c3a28f"
+checksum = "b011eec8cc36da2aab2d5cff675ec18454fad408585853910a202391cf9f8e65"
 dependencies = [
  "once_cell",
  "wasm-bindgen",
@@ -1064,37 +1044,31 @@ version = "1.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "bbd2bcb4c963f2ddae06a2efc7e9f3591312473c50c6685e1f298068316e66fe"
 
-[[package]]
-name = "lazycell"
-version = "1.3.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "830d08ce1d1d941e6b30645f1a0eb5643013d835ce3779a5fc208261dbe10f55"
-
 [[package]]
 name = "libc"
-version = "0.2.175"
+version = "0.2.177"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6a82ae493e598baaea5209805c49bbf2ea7de956d50d7da0da1164f9c6d28543"
+checksum = "2874a2af47a2325c2001a6e6fad9b16a53b802102b528163885171cf92b15976"
 
 [[package]]
 name = "libloading"
-version = "0.8.8"
+version = "0.8.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "07033963ba89ebaf1584d767badaa2e8fcec21aedea6b8c0346d487d49c28667"
+checksum = "d7c4b02199fee7c5d21a5ae7d8cfa79a6ef5bb2fc834d6e9058e89c825efdc55"
 dependencies = [
  "cfg-if",
- "windows-targets 0.53.3",
+ "windows-link",
 ]
 
 [[package]]
 name = "libredox"
-version = "0.1.9"
+version = "0.1.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "391290121bad3d37fbddad76d8f5d1c1c314cfc646d143d7e07a3086ddff0ce3"
+checksum = "416f7e718bdb06000964960ffa43b4335ad4012ae8b99060261aa4a8088d5ccb"
 dependencies = [
- "bitflags 2.9.3",
+ "bitflags 2.10.0",
  "libc",
- "redox_syscall 0.5.17",
+ "redox_syscall 0.5.18",
 ]
 
 [[package]]
@@ -1103,7 +1077,7 @@ version = "0.17.3+10.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cef2a00ee60fe526157c9023edab23943fae1ce2ab6f4abb2a807c1746835de9"
 dependencies = [
- "bindgen 0.72.1",
+ "bindgen",
  "bzip2-sys",
  "cc",
  "libc",
@@ -1125,31 +1099,24 @@ dependencies = [
 
 [[package]]
 name = "linux-raw-sys"
-version = "0.4.15"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d26c52dbd32dccf2d10cac7725f8eae5296885fb5703b261f7d0a0739ec807ab"
-
-[[package]]
-name = "linux-raw-sys"
-version = "0.9.4"
+version = "0.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cd945864f07fe9f5371a27ad7b52a172b4b499999f1d97574c9fa68373937e12"
+checksum = "df1d3c3b53da64cf5760482273a98e575c651a67eec7f77df96b5b642de8f039"
 
 [[package]]
 name = "lock_api"
-version = "0.4.13"
+version = "0.4.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "96936507f153605bddfcda068dd804796c84324ed2510809e5b2a624c81da765"
+checksum = "224399e74b87b5f3557511d98dff8b14089b3dadafcab6bb93eab67d3aace965"
 dependencies = [
- "autocfg",
  "scopeguard",
 ]
 
 [[package]]
 name = "log"
-version = "0.4.27"
+version = "0.4.28"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "13dc2df351e3202783a1fe0d44375f7295ffb4049267b0f3018346dc122a1d94"
+checksum = "34080505efa8e45a4b816c349525ebe327ceaa8559756f0356cba97ef3bf7432"
 
 [[package]]
 name = "lru"
@@ -1172,11 +1139,11 @@ dependencies = [
 
 [[package]]
 name = "matchers"
-version = "0.1.0"
+version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8263075bb86c5a1b1427b5ae862e8889656f126e9f77c484496e8b47cf5c5558"
+checksum = "d1525a2a28c7f4fa0fc98bb91ae755d1e2d1505079e05539e35bc876b5d65ae9"
 dependencies = [
- "regex-automata 0.1.10",
+ "regex-automata",
 ]
 
 [[package]]
@@ -1187,15 +1154,15 @@ checksum = "0e7465ac9959cc2b1404e8e2367b43684a6d13790fe23056cc8c6c5a6b7bcb94"
 
 [[package]]
 name = "memchr"
-version = "2.7.5"
+version = "2.7.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "32a282da65faaf38286cf3be983213fcf1d2e2a58700e808f83f4ea9a4804bc0"
+checksum = "f52b00d39961fc5b2736ea853c9cc86238e165017a493d1d5c8eac6bdc4cc273"
 
 [[package]]
 name = "memmap2"
-version = "0.9.8"
+version = "0.9.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "843a98750cd611cc2965a8213b53b43e715f13c37a9e096c6408e69990961db7"
+checksum = "744133e4a0e0a658e1374cf3bf8e415c4052a15a111acd372764c55b4177d490"
 dependencies = [
  "libc",
 ]
@@ -1221,12 +1188,12 @@ dependencies = [
  "hyper",
  "hyper-rustls",
  "hyper-util",
- "indexmap 2.11.0",
+ "indexmap 2.12.0",
  "ipnet",
  "metrics",
  "metrics-util",
  "quanta",
- "thiserror 2.0.16",
+ "thiserror 2.0.17",
  "tokio",
  "tracing",
 ]
@@ -1266,17 +1233,18 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1fa76a2c86f704bdb222d66965fb3d63269ce38518b83cb0575fca855ebb6316"
 dependencies = [
  "adler2",
+ "simd-adler32",
 ]
 
 [[package]]
 name = "mio"
-version = "1.0.4"
+version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "78bed444cc8a2160f01cbcf811ef18cac863ad68ae8ca62092e8db51d51c761c"
+checksum = "69d83b0086dc8ecf3ce9ae2874b2d1290252e2a30720bea58a5c6639b0092873"
 dependencies = [
  "libc",
- "wasi 0.11.1+wasi-snapshot-preview1",
- "windows-sys 0.59.0",
+ "wasi",
+ "windows-sys 0.61.2",
 ]
 
 [[package]]
@@ -1306,12 +1274,11 @@ dependencies = [
 
 [[package]]
 name = "nu-ansi-term"
-version = "0.46.0"
+version = "0.50.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "77a8165726e8236064dbb45459242600304b42a5ea24ee2948e18e023bf7ba84"
+checksum = "7957b9740744892f114936ab4a57b3f487491bbeafaf8083688b16841a4240e5"
 dependencies = [
- "overload",
- "winapi",
+ "windows-sys 0.61.2",
 ]
 
 [[package]]
@@ -1329,15 +1296,6 @@ dependencies = [
  "libc",
 ]
 
-[[package]]
-name = "object"
-version = "0.36.7"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "62948e14d923ea95ea2c7c86c71013138b66525b86bdc08d2dcc262bdb497b87"
-dependencies = [
- "memchr",
-]
-
 [[package]]
 name = "once_cell"
 version = "1.21.3"
@@ -1350,17 +1308,11 @@ version = "0.1.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d05e27ee213611ffe7d6348b942e8f942b37114c00cc03cec254295a4a17852e"
 
-[[package]]
-name = "overload"
-version = "0.1.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b15813163c1d831bf4a13c3610c05c0d03b39feb07f7e09fa234dac9b15aaf39"
-
 [[package]]
 name = "parking_lot"
-version = "0.12.4"
+version = "0.12.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "70d58bf43669b5795d1576d0641cfb6fbb2057bf629506267a92807158584a13"
+checksum = "93857453250e3077bd71ff98b6a65ea6621a19bb0f559a85248955ac12c45a1a"
 dependencies = [
  "lock_api",
  "parking_lot_core",
@@ -1368,15 +1320,15 @@ dependencies = [
 
 [[package]]
 name = "parking_lot_core"
-version = "0.9.11"
+version = "0.9.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bc838d2a56b5b1a6c25f55575dfc605fabb63bb2365f6c2353ef9159aa69e4a5"
+checksum = "2621685985a2ebf1c516881c026032ac7deafcda1a2c9b7850dc81e3dfcb64c1"
 dependencies = [
  "cfg-if",
  "libc",
- "redox_syscall 0.5.17",
+ "redox_syscall 0.5.18",
  "smallvec",
- "windows-targets 0.52.6",
+ "windows-link",
 ]
 
 [[package]]
@@ -1387,12 +1339,12 @@ checksum = "df94ce210e5bc13cb6651479fa48d14f601d9858cfe0467f43ae157023b938d3"
 
 [[package]]
 name = "pem"
-version = "3.0.5"
+version = "3.0.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "38af38e8470ac9dee3ce1bae1af9c1671fffc44ddfd8bd1d0a3445bf349a8ef3"
+checksum = "1d30c53c26bc5b31a98cd02d20f25a7c8567146caf63ed593a9d87b2775291be"
 dependencies = [
  "base64",
- "serde",
+ "serde_core",
 ]
 
 [[package]]
@@ -1408,7 +1360,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3672b37090dbd86368a4145bc067582552b29c27377cad4e0a306c97f9bd7772"
 dependencies = [
  "fixedbitset",
- "indexmap 2.11.0",
+ "indexmap 2.12.0",
 ]
 
 [[package]]
@@ -1482,9 +1434,9 @@ dependencies = [
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.101"
+version = "1.0.103"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "89ae43fd86e4158d6db51ad8e2b80f313af9cc74f5c0e03ccb87de09998732de"
+checksum = "5ee95bc4ef87b8d5ba32e8b7714ccc834865276eab0aed5c9958d00ec45f49e8"
 dependencies = [
  "unicode-ident",
 ]
@@ -1551,16 +1503,16 @@ dependencies = [
  "libc",
  "once_cell",
  "raw-cpuid",
- "wasi 0.11.1+wasi-snapshot-preview1",
+ "wasi",
  "web-sys",
  "winapi",
 ]
 
 [[package]]
 name = "quote"
-version = "1.0.40"
+version = "1.0.41"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1885c039570dc00dcb4ff087a89e185fd56bae234ddc7f056a945bf36467248d"
+checksum = "ce25767e7b499d1b604768e7cde645d14cc8584231ea6b295e9c9eb22c02e1d1"
 dependencies = [
  "proc-macro2",
 ]
@@ -1627,7 +1579,7 @@ version = "0.9.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "99d9a13982dcf210057a8a78572b2217b667c3beacbf3a0d8b454f6f82837d38"
 dependencies = [
- "getrandom 0.3.3",
+ "getrandom 0.3.4",
 ]
 
 [[package]]
@@ -1641,11 +1593,11 @@ dependencies = [
 
 [[package]]
 name = "raw-cpuid"
-version = "11.5.0"
+version = "11.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c6df7ab838ed27997ba19a4664507e6f82b41fe6e20be42929332156e5e85146"
+checksum = "498cd0dc59d73224351ee52a95fee0f1a617a2eae0e7d9d720cc622c73a54186"
 dependencies = [
- "bitflags 2.9.3",
+ "bitflags 2.10.0",
 ]
 
 [[package]]
@@ -1672,56 +1624,41 @@ dependencies = [
 
 [[package]]
 name = "redox_syscall"
-version = "0.5.17"
+version = "0.5.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5407465600fb0548f1442edf71dd20683c6ed326200ace4b1ef0763521bb3b77"
+checksum = "ed2bf2547551a7053d6fdfafda3f938979645c44812fbfcda098faae3f1a362d"
 dependencies = [
- "bitflags 2.9.3",
+ "bitflags 2.10.0",
 ]
 
 [[package]]
 name = "regex"
-version = "1.11.1"
+version = "1.12.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b544ef1b4eac5dc2db33ea63606ae9ffcfac26c1416a2806ae0bf5f56b201191"
+checksum = "843bc0191f75f3e22651ae5f1e72939ab2f72a4bc30fa80a066bd66edefc24d4"
 dependencies = [
  "aho-corasick",
  "memchr",
- "regex-automata 0.4.9",
- "regex-syntax 0.8.5",
-]
-
-[[package]]
-name = "regex-automata"
-version = "0.1.10"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6c230d73fb8d8c1b9c0b3135c5142a8acee3a0558fb8db5cf1cb65f8d7862132"
-dependencies = [
- "regex-syntax 0.6.29",
+ "regex-automata",
+ "regex-syntax",
 ]
 
 [[package]]
 name = "regex-automata"
-version = "0.4.9"
+version = "0.4.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "809e8dc61f6de73b46c85f4c96486310fe304c434cfa43669d7b40f711150908"
+checksum = "5276caf25ac86c8d810222b3dbb938e512c55c6831a10f3e6ed1c93b84041f1c"
 dependencies = [
  "aho-corasick",
  "memchr",
- "regex-syntax 0.8.5",
+ "regex-syntax",
 ]
 
 [[package]]
 name = "regex-syntax"
-version = "0.6.29"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f162c6dd7b008981e4d40210aca20b4bd0f9b60ca9271061b07f78537722f2e1"
-
-[[package]]
-name = "regex-syntax"
-version = "0.8.5"
+version = "0.8.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2b15c43186be67a4fd63bee50d0303afffcef381492ebe2c5d87f324e1b8815c"
+checksum = "7a2d987857b319362043e95f5353c0535c1f58eec5336fdfcf626430af7def58"
 
 [[package]]
 name = "ring"
@@ -1749,7 +1686,7 @@ dependencies = [
 
 [[package]]
 name = "rocksdb-demo"
-version = "0.1.3"
+version = "0.2.0"
 dependencies = [
  "async-trait",
  "bincode 2.0.1",
@@ -1763,18 +1700,6 @@ dependencies = [
  "tracing-subscriber",
 ]
 
-[[package]]
-name = "rustc-demangle"
-version = "0.1.26"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "56f7d92ca342cea22a06f2121d944b4fd82af56988c270852495420f961d4ace"
-
-[[package]]
-name = "rustc-hash"
-version = "1.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "08d43f7aa6b08d49f382cde6a7982047c3426db949b1424bc4b7ec9ae12c6ce2"
-
 [[package]]
 name = "rustc-hash"
 version = "2.1.1"
@@ -1783,35 +1708,22 @@ checksum = "357703d41365b4b27c590e3ed91eabb1b663f07c4c084095e60cbed4362dff0d"
 
 [[package]]
 name = "rustix"
-version = "0.38.44"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fdb5bc1ae2baa591800df16c9ca78619bf65c0488b41b96ccec5d11220d8c154"
-dependencies = [
- "bitflags 2.9.3",
- "errno",
- "libc",
- "linux-raw-sys 0.4.15",
- "windows-sys 0.59.0",
-]
-
-[[package]]
-name = "rustix"
-version = "1.0.8"
+version = "1.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "11181fbabf243db407ef8df94a6ce0b2f9a733bd8be4ad02b4eda9602296cac8"
+checksum = "cd15f8a2c5551a84d56efdc1cd049089e409ac19a3072d5037a17fd70719ff3e"
 dependencies = [
- "bitflags 2.9.3",
+ "bitflags 2.10.0",
  "errno",
  "libc",
- "linux-raw-sys 0.9.4",
- "windows-sys 0.60.2",
+ "linux-raw-sys",
+ "windows-sys 0.61.2",
 ]
 
 [[package]]
 name = "rustls"
-version = "0.23.31"
+version = "0.23.34"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c0ebcbd2f03de0fc1122ad9bb24b127a5a6cd51d72604a3f3c50ac459762b6cc"
+checksum = "6a9586e9ee2b4f8fab52a0048ca7334d7024eef48e2cb9407e3497bb7cab7fa7"
 dependencies = [
  "aws-lc-rs",
  "log",
@@ -1825,9 +1737,9 @@ dependencies = [
 
 [[package]]
 name = "rustls-native-certs"
-version = "0.8.1"
+version = "0.8.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7fcff2dd52b58a8d98a70243663a0d234c4e2b79235637849d15913394a247d3"
+checksum = "9980d917ebb0c0536119ba501e90834767bffc3d60641457fd84a1f3fd337923"
 dependencies = [
  "openssl-probe",
  "rustls-pki-types",
@@ -1846,18 +1758,18 @@ dependencies = [
 
 [[package]]
 name = "rustls-pki-types"
-version = "1.12.0"
+version = "1.13.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "229a4a4c221013e7e1f1a043678c5cc39fe5171437c88fb47151a21e6f5b5c79"
+checksum = "94182ad936a0c91c324cd46c6511b9510ed16af436d7b5bab34beab0afd55f7a"
 dependencies = [
  "zeroize",
 ]
 
 [[package]]
 name = "rustls-webpki"
-version = "0.103.4"
+version = "0.103.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0a17884ae0c1b773f1ccd2bd4a8c72f16da897310a98b0e84bf349ad5ead92fc"
+checksum = "2ffdfa2f5286e2247234e03f680868ac2815974dc39e00ea15adc445d0aafe52"
 dependencies = [
  "aws-lc-rs",
  "ring",
@@ -1879,11 +1791,11 @@ checksum = "28d3b2b1366ec20994f1fd18c3c594f05c5dd4bc44d8bb0c1c632c8d6829481f"
 
 [[package]]
 name = "schannel"
-version = "0.1.27"
+version = "0.1.28"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1f29ebaa345f945cec9fbbc532eb307f0fdad8161f281b6369539c8d84876b3d"
+checksum = "891d81b926048e76efe18581bf793546b4c0eaf8448d72be8de2bbee5fd166e1"
 dependencies = [
- "windows-sys 0.59.0",
+ "windows-sys 0.61.2",
 ]
 
 [[package]]
@@ -1894,11 +1806,11 @@ checksum = "94143f37725109f92c262ed2cf5e59bce7498c01bcc1502d7b9afe439a4e9f49"
 
 [[package]]
 name = "security-framework"
-version = "3.3.0"
+version = "3.5.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "80fb1d92c5028aa318b4b8bd7302a5bfcf48be96a37fc6fc790f806b0004ee0c"
+checksum = "b3297343eaf830f66ede390ea39da1d462b6b0c1b000f420d0a83f898bbbe6ef"
 dependencies = [
- "bitflags 2.9.3",
+ "bitflags 2.10.0",
  "core-foundation",
  "core-foundation-sys",
  "libc",
@@ -1907,9 +1819,9 @@ dependencies = [
 
 [[package]]
 name = "security-framework-sys"
-version = "2.14.0"
+version = "2.15.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "49db231d56a190491cb4aeda9527f1ad45345af50b0851622a7adb8c03b01c32"
+checksum = "cc1f0cbffaac4852523ce30d8bd3c5cdc873501d96ff467ca09b6767bb8cd5c0"
 dependencies = [
  "core-foundation-sys",
  "libc",
@@ -1917,18 +1829,28 @@ dependencies = [
 
 [[package]]
 name = "serde"
-version = "1.0.219"
+version = "1.0.228"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5f0e2c6ed6606019b4e29e69dbaba95b11854410e5347d525002456dbbb786b6"
+checksum = "9a8e94ea7f378bd32cbbd37198a4a91436180c5bb472411e48b5ec2e2124ae9e"
+dependencies = [
+ "serde_core",
+ "serde_derive",
+]
+
+[[package]]
+name = "serde_core"
+version = "1.0.228"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "41d385c7d4ca58e59fc732af25c3983b67ac852c1a25000afe1175de458b67ad"
 dependencies = [
  "serde_derive",
 ]
 
 [[package]]
 name = "serde_derive"
-version = "1.0.219"
+version = "1.0.228"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5b0276cf7f2c73365f7157c8123c21cd9a50fbbd844757af28ca1f5925fc2a00"
+checksum = "d540f220d3187173da220f885ab66608367b6574e925011a9353e4badda91d79"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -1937,14 +1859,15 @@ dependencies = [
 
 [[package]]
 name = "serde_json"
-version = "1.0.143"
+version = "1.0.145"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d401abef1d108fbd9cbaebc3e46611f4b1021f714a0597a71f41ee463f5f4a5a"
+checksum = "402a6f66d8c709116cf22f558eab210f5a50187f702eb4d7e5ef38d9a7f1c79c"
 dependencies = [
  "itoa",
  "memchr",
  "ryu",
  "serde",
+ "serde_core",
 ]
 
 [[package]]
@@ -1991,6 +1914,12 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "simd-adler32"
+version = "0.3.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d66dc143e6b11c1eddc06d5c423cfc97062865baf299914ab64caa38182078fe"
+
 [[package]]
 name = "sketches-ddsketch"
 version = "0.3.0"
@@ -2021,12 +1950,12 @@ dependencies = [
 
 [[package]]
 name = "socket2"
-version = "0.6.0"
+version = "0.6.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "233504af464074f9d066d7b5416c5f9b894a5862a6506e306f7b816cdd6f1807"
+checksum = "17129e116933cf371d018bb80ae557e889637989d8638274fb25622827b03881"
 dependencies = [
  "libc",
- "windows-sys 0.59.0",
+ "windows-sys 0.60.2",
 ]
 
 [[package]]
@@ -2037,9 +1966,9 @@ checksum = "13c2bddecc57b384dee18652358fb23172facb8a2c51ccc10d74c157bdea3292"
 
 [[package]]
 name = "syn"
-version = "2.0.106"
+version = "2.0.108"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ede7c438028d4436d71104916910f5bb611972c5cfd7f89b8300a8186e6fada6"
+checksum = "da58917d35242480a05c2897064da0a80589a2a0476c9a3f2fdc83b53502e917"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -2054,15 +1983,15 @@ checksum = "0bf256ce5efdfa370213c1dabab5935a12e49f2c58d15e9eac2870d3b4f27263"
 
 [[package]]
 name = "tempfile"
-version = "3.21.0"
+version = "3.23.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "15b61f8f20e3a6f7e0649d825294eaf317edce30f82cf6026e7e4cb9222a7d1e"
+checksum = "2d31c77bdf42a745371d260a26ca7163f1e0924b64afa0b688e61b5a9fa02f16"
 dependencies = [
  "fastrand",
- "getrandom 0.3.3",
+ "getrandom 0.3.4",
  "once_cell",
- "rustix 1.0.8",
- "windows-sys 0.60.2",
+ "rustix",
+ "windows-sys 0.61.2",
 ]
 
 [[package]]
@@ -2076,11 +2005,11 @@ dependencies = [
 
 [[package]]
 name = "thiserror"
-version = "2.0.16"
+version = "2.0.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3467d614147380f2e4e374161426ff399c91084acd2363eaf549172b3d5e60c0"
+checksum = "f63587ca0f12b72a0600bcba1d40081f830876000bb46dd2337a3051618f4fc8"
 dependencies = [
- "thiserror-impl 2.0.16",
+ "thiserror-impl 2.0.17",
 ]
 
 [[package]]
@@ -2096,9 +2025,9 @@ dependencies = [
 
 [[package]]
 name = "thiserror-impl"
-version = "2.0.16"
+version = "2.0.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6c5e1be1c48b9172ee610da68fd9cd2770e7a4056cb3fc98710ee6906f0c7960"
+checksum = "3ff15c8ecd7de3849db632e14d18d2571fa09dfc5ed93479bc4485c7a517c913"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -2116,9 +2045,9 @@ dependencies = [
 
 [[package]]
 name = "time"
-version = "0.3.41"
+version = "0.3.44"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8a7619e19bc266e0f9c5e6686659d394bc57973859340060a69221e57dbc0c40"
+checksum = "91e7d9e3bb61134e77bde20dd4825b97c010155709965fedf0f49bb138e52a9d"
 dependencies = [
  "deranged",
  "itoa",
@@ -2133,15 +2062,15 @@ dependencies = [
 
 [[package]]
 name = "time-core"
-version = "0.1.4"
+version = "0.1.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c9e9a38711f559d9e3ce1cdb06dd7c5b8ea546bc90052da6d06bb76da74bb07c"
+checksum = "40868e7c1d2f0b8d73e4a8c7f0ff63af4f6d19be117e90bd73eb1d62cf831c6b"
 
 [[package]]
 name = "time-macros"
-version = "0.2.22"
+version = "0.2.24"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3526739392ec93fd8b359c8e98514cb3e8e021beb4e5f597b00a0221f8ed8a49"
+checksum = "30cfb0125f12d9c277f35663a0a33f8c30190f4e4574868a330595412d34ebf3"
 dependencies = [
  "num-conv",
  "time-core",
@@ -2149,28 +2078,25 @@ dependencies = [
 
 [[package]]
 name = "tokio"
-version = "1.47.1"
+version = "1.48.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "89e49afdadebb872d3145a5638b59eb0691ea23e46ca484037cfab3b76b95038"
+checksum = "ff360e02eab121e0bc37a2d3b4d4dc622e6eda3a8e5253d5435ecf5bd4c68408"
 dependencies = [
- "backtrace",
  "bytes",
- "io-uring",
  "libc",
  "mio",
  "pin-project-lite",
  "signal-hook-registry",
- "slab",
- "socket2 0.6.0",
+ "socket2 0.6.1",
  "tokio-macros",
- "windows-sys 0.59.0",
+ "windows-sys 0.61.2",
 ]
 
 [[package]]
 name = "tokio-macros"
-version = "2.5.0"
+version = "2.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6e06d43f1345a3bcd39f6a56dbb7dcab2ba47e68e8ac134855e7e2bdbaf8cab8"
+checksum = "af407857209536a95c8e56f8231ef2c2e2aff839b22e07a1ffcbc617e9db9fa5"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -2179,9 +2105,9 @@ dependencies = [
 
 [[package]]
 name = "tokio-rustls"
-version = "0.26.2"
+version = "0.26.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8e727b36a1a0e8b74c376ac2211e40c2c8af09fb4013c60d910495810f008e9b"
+checksum = "1729aa945f29d91ba541258c8df89027d5792d85a8841fb65e8bf0f4ede4ef61"
 dependencies = [
  "rustls",
  "tokio",
@@ -2253,7 +2179,7 @@ version = "0.22.27"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "41fe8c660ae4257887cf66394862d21dbca4a6ddd26f04a3560410406a2f819a"
 dependencies = [
- "indexmap 2.11.0",
+ "indexmap 2.12.0",
  "serde",
  "serde_spanned",
  "toml_datetime",
@@ -2440,14 +2366,14 @@ dependencies = [
 
 [[package]]
 name = "tracing-subscriber"
-version = "0.3.19"
+version = "0.3.20"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e8189decb5ac0fa7bc8b96b7cb9b2701d60d48805aca84a238004d665fcc4008"
+checksum = "2054a14f5307d601f88daf0553e1cbf472acc4f2c51afab632431cdcd72124d5"
 dependencies = [
  "matchers",
  "nu-ansi-term",
  "once_cell",
- "regex",
+ "regex-automata",
  "serde",
  "serde_json",
  "sharded-slab",
@@ -2467,15 +2393,15 @@ checksum = "e421abadd41a4225275504ea4d6566923418b7f05506fbc9c0fe86ba7396114b"
 
 [[package]]
 name = "typenum"
-version = "1.18.0"
+version = "1.19.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1dccffe3ce07af9386bfd29e80c0ab1a8205a2fc34e4bcd40364df902cfa8f3f"
+checksum = "562d481066bde0658276a35467c4af00bdc6ee726305698a55b86e61d7ad82bb"
 
 [[package]]
 name = "unicode-ident"
-version = "1.0.18"
+version = "1.0.22"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5a5f39404a5da50712a4c1eecf25e90dd62b613502b7e925fd4e4d19b5c96512"
+checksum = "9312f7c4f6ff9069b165498234ce8be658059c6728633667c526e27dc2cf1df5"
 
 [[package]]
 name = "untrusted"
@@ -2541,44 +2467,32 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ccf3ec651a847eb01de73ccad15eb7d99f80485de043efb2f370cd654f4ea44b"
 
 [[package]]
-name = "wasi"
-version = "0.14.2+wasi-0.2.4"
+name = "wasip2"
+version = "1.0.1+wasi-0.2.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9683f9a5a998d873c0d21fcbe3c083009670149a8fab228644b8bd36b2c48cb3"
+checksum = "0562428422c63773dad2c345a1882263bbf4d65cf3f42e90921f787ef5ad58e7"
 dependencies = [
- "wit-bindgen-rt",
+ "wit-bindgen",
 ]
 
 [[package]]
 name = "wasm-bindgen"
-version = "0.2.100"
+version = "0.2.105"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1edc8929d7499fc4e8f0be2262a241556cfc54a0bea223790e71446f2aab1ef5"
+checksum = "da95793dfc411fbbd93f5be7715b0578ec61fe87cb1a42b12eb625caa5c5ea60"
 dependencies = [
  "cfg-if",
  "once_cell",
+ "rustversion",
  "wasm-bindgen-macro",
-]
-
-[[package]]
-name = "wasm-bindgen-backend"
-version = "0.2.100"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2f0a0651a5c2bc21487bde11ee802ccaf4c51935d0d3d42a6101f98161700bc6"
-dependencies = [
- "bumpalo",
- "log",
- "proc-macro2",
- "quote",
- "syn",
  "wasm-bindgen-shared",
 ]
 
 [[package]]
 name = "wasm-bindgen-macro"
-version = "0.2.100"
+version = "0.2.105"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7fe63fc6d09ed3792bd0897b314f53de8e16568c2b3f7982f468c0bf9bd0b407"
+checksum = "04264334509e04a7bf8690f2384ef5265f05143a4bff3889ab7a3269adab59c2"
 dependencies = [
  "quote",
  "wasm-bindgen-macro-support",
@@ -2586,48 +2500,36 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-macro-support"
-version = "0.2.100"
+version = "0.2.105"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8ae87ea40c9f689fc23f209965b6fb8a99ad69aeeb0231408be24920604395de"
+checksum = "420bc339d9f322e562942d52e115d57e950d12d88983a14c79b86859ee6c7ebc"
 dependencies = [
+ "bumpalo",
  "proc-macro2",
  "quote",
  "syn",
- "wasm-bindgen-backend",
  "wasm-bindgen-shared",
 ]
 
 [[package]]
 name = "wasm-bindgen-shared"
-version = "0.2.100"
+version = "0.2.105"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1a05d73b933a847d6cccdda8f838a22ff101ad9bf93e33684f39c1f5f0eece3d"
+checksum = "76f218a38c84bcb33c25ec7059b07847d465ce0e0a76b995e134a45adcb6af76"
 dependencies = [
  "unicode-ident",
 ]
 
 [[package]]
 name = "web-sys"
-version = "0.3.77"
+version = "0.3.82"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "33b6dd2ef9186f1f2072e409e99cd22a975331a6b3591b12c764e0e55c60d5d2"
+checksum = "3a1f95c0d03a47f4ae1f7a64643a6bb97465d9b740f0fa8f90ea33915c99a9a1"
 dependencies = [
  "js-sys",
  "wasm-bindgen",
 ]
 
-[[package]]
-name = "which"
-version = "4.4.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "87ba24419a2078cd2b0f2ede2691b6c66d8e47836da3b6db8265ebad47afbfc7"
-dependencies = [
- "either",
- "home",
- "once_cell",
- "rustix 0.38.44",
-]
-
 [[package]]
 name = "winapi"
 version = "0.3.9"
@@ -2652,9 +2554,9 @@ checksum = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
 
 [[package]]
 name = "windows-link"
-version = "0.1.3"
+version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5e6ad25900d524eaabdbbb96d20b4311e1e7ae1699af4fb28c17ae66c80d798a"
+checksum = "f0805222e57f7521d6a62e36fa9163bc891acd422f971defe97d64e70d0a4fe5"
 
 [[package]]
 name = "windows-sys"
@@ -2667,20 +2569,20 @@ dependencies = [
 
 [[package]]
 name = "windows-sys"
-version = "0.59.0"
+version = "0.60.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1e38bc4d79ed67fd075bcc251a1c39b32a1776bbe92e5bef1f0bf1f8c531853b"
+checksum = "f2f500e4d28234f72040990ec9d39e3a6b950f9f22d3dba18416c35882612bcb"
 dependencies = [
- "windows-targets 0.52.6",
+ "windows-targets 0.53.5",
 ]
 
 [[package]]
 name = "windows-sys"
-version = "0.60.2"
+version = "0.61.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f2f500e4d28234f72040990ec9d39e3a6b950f9f22d3dba18416c35882612bcb"
+checksum = "ae137229bcbd6cdf0f7b80a31df61766145077ddf49416a728b02cb3921ff3fc"
 dependencies = [
- "windows-targets 0.53.3",
+ "windows-link",
 ]
 
 [[package]]
@@ -2701,19 +2603,19 @@ dependencies = [
 
 [[package]]
 name = "windows-targets"
-version = "0.53.3"
+version = "0.53.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d5fe6031c4041849d7c496a8ded650796e7b6ecc19df1a431c1a363342e5dc91"
+checksum = "4945f9f551b88e0d65f3db0bc25c33b8acea4d9e41163edf90dcd0b19f9069f3"
 dependencies = [
  "windows-link",
- "windows_aarch64_gnullvm 0.53.0",
- "windows_aarch64_msvc 0.53.0",
- "windows_i686_gnu 0.53.0",
- "windows_i686_gnullvm 0.53.0",
- "windows_i686_msvc 0.53.0",
- "windows_x86_64_gnu 0.53.0",
- "windows_x86_64_gnullvm 0.53.0",
- "windows_x86_64_msvc 0.53.0",
+ "windows_aarch64_gnullvm 0.53.1",
+ "windows_aarch64_msvc 0.53.1",
+ "windows_i686_gnu 0.53.1",
+ "windows_i686_gnullvm 0.53.1",
+ "windows_i686_msvc 0.53.1",
+ "windows_x86_64_gnu 0.53.1",
+ "windows_x86_64_gnullvm 0.53.1",
+ "windows_x86_64_msvc 0.53.1",
 ]
 
 [[package]]
@@ -2724,9 +2626,9 @@ checksum = "32a4622180e7a0ec044bb555404c800bc9fd9ec262ec147edd5989ccd0c02cd3"
 
 [[package]]
 name = "windows_aarch64_gnullvm"
-version = "0.53.0"
+version = "0.53.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "86b8d5f90ddd19cb4a147a5fa63ca848db3df085e25fee3cc10b39b6eebae764"
+checksum = "a9d8416fa8b42f5c947f8482c43e7d89e73a173cead56d044f6a56104a6d1b53"
 
 [[package]]
 name = "windows_aarch64_msvc"
@@ -2736,9 +2638,9 @@ checksum = "09ec2a7bb152e2252b53fa7803150007879548bc709c039df7627cabbd05d469"
 
 [[package]]
 name = "windows_aarch64_msvc"
-version = "0.53.0"
+version = "0.53.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c7651a1f62a11b8cbd5e0d42526e55f2c99886c77e007179efff86c2b137e66c"
+checksum = "b9d782e804c2f632e395708e99a94275910eb9100b2114651e04744e9b125006"
 
 [[package]]
 name = "windows_i686_gnu"
@@ -2748,9 +2650,9 @@ checksum = "8e9b5ad5ab802e97eb8e295ac6720e509ee4c243f69d781394014ebfe8bbfa0b"
 
 [[package]]
 name = "windows_i686_gnu"
-version = "0.53.0"
+version = "0.53.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c1dc67659d35f387f5f6c479dc4e28f1d4bb90ddd1a5d3da2e5d97b42d6272c3"
+checksum = "960e6da069d81e09becb0ca57a65220ddff016ff2d6af6a223cf372a506593a3"
 
 [[package]]
 name = "windows_i686_gnullvm"
@@ -2760,9 +2662,9 @@ checksum = "0eee52d38c090b3caa76c563b86c3a4bd71ef1a819287c19d586d7334ae8ed66"
 
 [[package]]
 name = "windows_i686_gnullvm"
-version = "0.53.0"
+version = "0.53.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9ce6ccbdedbf6d6354471319e781c0dfef054c81fbc7cf83f338a4296c0cae11"
+checksum = "fa7359d10048f68ab8b09fa71c3daccfb0e9b559aed648a8f95469c27057180c"
 
 [[package]]
 name = "windows_i686_msvc"
@@ -2772,9 +2674,9 @@ checksum = "240948bc05c5e7c6dabba28bf89d89ffce3e303022809e73deaefe4f6ec56c66"
 
 [[package]]
 name = "windows_i686_msvc"
-version = "0.53.0"
+version = "0.53.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "581fee95406bb13382d2f65cd4a908ca7b1e4c2f1917f143ba16efe98a589b5d"
+checksum = "1e7ac75179f18232fe9c285163565a57ef8d3c89254a30685b57d83a38d326c2"
 
 [[package]]
 name = "windows_x86_64_gnu"
@@ -2784,9 +2686,9 @@ checksum = "147a5c80aabfbf0c7d901cb5895d1de30ef2907eb21fbbab29ca94c5b08b1a78"
 
 [[package]]
 name = "windows_x86_64_gnu"
-version = "0.53.0"
+version = "0.53.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2e55b5ac9ea33f2fc1716d1742db15574fd6fc8dadc51caab1c16a3d3b4190ba"
+checksum = "9c3842cdd74a865a8066ab39c8a7a473c0778a3f29370b5fd6b4b9aa7df4a499"
 
 [[package]]
 name = "windows_x86_64_gnullvm"
@@ -2796,9 +2698,9 @@ checksum = "24d5b23dc417412679681396f2b49f3de8c1473deb516bd34410872eff51ed0d"
 
 [[package]]
 name = "windows_x86_64_gnullvm"
-version = "0.53.0"
+version = "0.53.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0a6e035dd0599267ce1ee132e51c27dd29437f63325753051e71dd9e42406c57"
+checksum = "0ffa179e2d07eee8ad8f57493436566c7cc30ac536a3379fdf008f47f6bb7ae1"
 
 [[package]]
 name = "windows_x86_64_msvc"
@@ -2808,9 +2710,9 @@ checksum = "589f6da84c646204747d1270a2a5661ea66ed1cced2631d546fdfb155959f9ec"
 
 [[package]]
 name = "windows_x86_64_msvc"
-version = "0.53.0"
+version = "0.53.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "271414315aff87387382ec3d271b52d7ae78726f5d44ac98b4f4030c91880486"
+checksum = "d6bbff5f0aada427a1e5a6da5f1f98158182f26556f345ac9e04d36d0ebed650"
 
 [[package]]
 name = "winnow"
@@ -2822,22 +2724,19 @@ dependencies = [
 ]
 
 [[package]]
-name = "wit-bindgen-rt"
-version = "0.39.0"
+name = "wit-bindgen"
+version = "0.46.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6f42320e61fe2cfd34354ecb597f86f413484a798ba44a8ca1165c58d42da6c1"
-dependencies = [
- "bitflags 2.9.3",
-]
+checksum = "f17a85883d4e6d00e8a97c586de764dabcc06133f7f1d55dce5cdc070ad7fe59"
 
 [[package]]
 name = "xattr"
-version = "1.5.1"
+version = "1.6.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "af3a19837351dc82ba89f8a125e22a3c475f05aba604acc023d62b2739ae2909"
+checksum = "32e45ad4206f6d2479085147f02bc2ef834ac85886624a23575ae137c8aa8156"
 dependencies = [
  "libc",
- "rustix 1.0.8",
+ "rustix",
 ]
 
 [[package]]
@@ -2851,18 +2750,18 @@ dependencies = [
 
 [[package]]
 name = "zerocopy"
-version = "0.8.26"
+version = "0.8.27"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1039dd0d3c310cf05de012d8a39ff557cb0d23087fd44cad61df08fc31907a2f"
+checksum = "0894878a5fa3edfd6da3f88c4805f4c8558e2b996227a3d864f47fe11e38282c"
 dependencies = [
  "zerocopy-derive",
 ]
 
 [[package]]
 name = "zerocopy-derive"
-version = "0.8.26"
+version = "0.8.27"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9ecf5b4cc5364572d7f4c329661bcc82724222973f2cab6f050a4e5c22f75181"
+checksum = "88d2b8d9c68ad2b9e4340d7832716a4d21a22a1154777ad56ea55c51a9cf3831"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -2871,15 +2770,15 @@ dependencies = [
 
 [[package]]
 name = "zeroize"
-version = "1.8.1"
+version = "1.8.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ced3678a2879b30306d323f4542626697a464a97c0a07c9aebf7ebca65cd4dde"
+checksum = "b97154e67e32c85465826e8bcc1c59429aaaf107c1e4a9e53c8d8ccd5eff88d0"
 
 [[package]]
 name = "zstd-sys"
-version = "2.0.15+zstd.1.5.7"
+version = "2.0.16+zstd.1.5.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "eb81183ddd97d0c74cedf1d50d85c8d08c1b8b68ee863bdee9e706eedba1a237"
+checksum = "91e19ebc2adc8f83e43039e79776e3fda8ca919132d68a1fed6a5faca2683748"
 dependencies = [
  "cc",
  "pkg-config",
diff --git a/examples/rocksdb-cluster/Cargo.toml b/examples/rocksdb-cluster/Cargo.toml
index d2de9124..212a2283 100644
--- a/examples/rocksdb-cluster/Cargo.toml
+++ b/examples/rocksdb-cluster/Cargo.toml
@@ -1,11 +1,11 @@
 [package]
 name = "rocksdb-demo"
-version = "0.1.3"
-edition = "2021"
+version = "0.2.0"
+edition = "2024"
 
 [dependencies]
+d-engine = { path = "../../d-engine", features = ["server", "rocksdb"] }
 # d-engine = "0.1.4"
-d-engine = { path = "../../../d-engine", features = ["rocksdb"] }
 
 bytes = "1.10"
 prost = { version = "0.13", default-features = false }
diff --git a/examples/rocksdb-cluster/src/main.rs b/examples/rocksdb-cluster/src/main.rs
index f61e9bdd..311bc60f 100644
--- a/examples/rocksdb-cluster/src/main.rs
+++ b/examples/rocksdb-cluster/src/main.rs
@@ -1,13 +1,13 @@
-use d_engine::file_io::open_file_for_append;
 use d_engine::NodeBuilder;
 use d_engine::{RocksDBStateMachine, RocksDBStorageEngine};
 use std::env;
 use std::error::Error;
+use std::fs::OpenOptions;
 use std::path::{Path, PathBuf};
 use std::sync::Arc;
 use std::time::Duration;
-use tokio::signal::unix::signal;
 use tokio::signal::unix::SignalKind;
+use tokio::signal::unix::signal;
 use tokio::sync::watch;
 use tracing::{error, info};
 use tracing_appender::non_blocking::WorkerGuard;
@@ -125,3 +125,16 @@ async fn graceful_shutdown(graceful_tx: watch::Sender<()>) {
 
     info!("Shutdown completed");
 }
+
+fn open_file_for_append(path: PathBuf) -> Result<std::fs::File, Box<dyn Error>> {
+    // Create parent directories if they don't exist
+    if let Some(parent) = path.parent() {
+        if parent != Path::new("") {
+            std::fs::create_dir_all(parent)?;
+        }
+    }
+
+    let log_file = OpenOptions::new().append(true).create(true).open(&path)?;
+
+    Ok(log_file)
+}
diff --git a/examples/sled-cluster/Cargo.toml b/examples/sled-cluster/Cargo.toml
index 0acdb615..0f3f4551 100644
--- a/examples/sled-cluster/Cargo.toml
+++ b/examples/sled-cluster/Cargo.toml
@@ -4,9 +4,8 @@ version = "0.1.3"
 edition = "2021"
 
 [dependencies]
+d-engine = { path = "../../d-engine", features = ["server"] }
 # d-engine = "0.1.4"
-d-engine = { path = "../../../d-engine" }
-
 
 sled = { version = "0.34.7", features = [
     "compression",
diff --git a/examples/sled-cluster/src/converters.rs b/examples/sled-cluster/src/converters.rs
new file mode 100644
index 00000000..ad4a1da9
--- /dev/null
+++ b/examples/sled-cluster/src/converters.rs
@@ -0,0 +1,47 @@
+//! Helper functions for converting between u64 and byte arrays.
+//!
+//! This module provides utility functions for serializing/deserializing
+//! u64 values to/from byte arrays used as keys in sled.
+
+use d_engine::StorageError;
+use sled::IVec;
+
+/// Convert a u64 value to an 8-byte big-endian vector.
+///
+/// # Arguments
+/// * `value` - The u64 value to convert
+///
+/// # Returns
+/// An 8-byte vector in big-endian byte order
+#[inline]
+pub(crate) fn safe_kv(value: u64) -> Vec<u8> {
+    value.to_be_bytes().to_vec()
+}
+
+/// Convert an 8-byte big-endian slice to a u64 value.
+///
+/// # Arguments
+/// * `bytes` - A byte slice to convert
+///
+/// # Returns
+/// `Ok(u64)` if the slice is exactly 8 bytes, `Err` otherwise
+#[inline]
+pub(crate) fn safe_vk(bytes: &[u8]) -> Result<u64, StorageError> {
+    if bytes.len() != 8 {
+        return Err(StorageError::DbError(format!(
+            "Invalid byte length: expected 8, got {}",
+            bytes.len()
+        )));
+    }
+    let mut arr = [0u8; 8];
+    arr.copy_from_slice(bytes);
+    Ok(u64::from_be_bytes(arr))
+}
+
+/// Convert an IVec (sled's byte vector) to a u64 value.
+///
+/// This is a convenience wrapper around `safe_vk` for sled's IVec type.
+#[inline]
+pub(crate) fn safe_vk_ivec(ivec: IVec) -> Result<u64, StorageError> {
+    safe_vk(&ivec[..])
+}
diff --git a/examples/sled-cluster/src/lib.rs b/examples/sled-cluster/src/lib.rs
index b55f4174..c6e7d5fd 100644
--- a/examples/sled-cluster/src/lib.rs
+++ b/examples/sled-cluster/src/lib.rs
@@ -1,5 +1,7 @@
+mod converters;
 mod sled_state_machine;
 mod sled_storage_engine;
+pub(crate) use converters::{safe_kv, safe_vk, safe_vk_ivec};
 pub use sled_state_machine::*;
 pub use sled_storage_engine::*;
 
diff --git a/examples/sled-cluster/src/main.rs b/examples/sled-cluster/src/main.rs
index 46d272aa..14106b96 100644
--- a/examples/sled-cluster/src/main.rs
+++ b/examples/sled-cluster/src/main.rs
@@ -1,8 +1,8 @@
-use d_engine::file_io::open_file_for_append;
 use d_engine::NodeBuilder;
 use sled_demo::{SledStateMachine, SledStorageEngine};
 use std::env;
 use std::error::Error;
+use std::fs::{File, OpenOptions};
 use std::path::{Path, PathBuf};
 use std::sync::Arc;
 use std::time::Duration;
@@ -90,6 +90,21 @@ async fn start_dengine_server(
     println!("Exiting program.");
 }
 
+/// Opens a file for appending, creating parent directories if needed
+fn open_file_for_append<P: AsRef<Path>>(path: P) -> std::io::Result<File> {
+    let path = path.as_ref();
+
+    // Create parent directories if they don't exist
+    if let Some(parent) = path.parent() {
+        if !parent.as_os_str().is_empty() {
+            std::fs::create_dir_all(parent)?;
+        }
+    }
+
+    // Open file for appending, create if doesn't exist
+    OpenOptions::new().create(true).append(true).open(path)
+}
+
 pub fn init_observability(log_dir: String) -> Result<WorkerGuard, Box<dyn Error + Send>> {
     let log_file = open_file_for_append(Path::new(&log_dir).join("d.log")).unwrap();
 
diff --git a/examples/sled-cluster/src/sled_engine_test.rs b/examples/sled-cluster/src/sled_engine_test.rs
index 162b5549..12d0e277 100644
--- a/examples/sled-cluster/src/sled_engine_test.rs
+++ b/examples/sled-cluster/src/sled_engine_test.rs
@@ -1,10 +1,12 @@
 use super::*;
-use async_trait::async_trait;
 use bytes::{Bytes, BytesMut};
 use d_engine::{
-    proto::{client::write_command::Insert, common::Entry},
-    storage_engine_test::{StorageEngineBuilder, StorageEngineTestSuite},
-    Error, LogStore, StorageEngine,
+    client::{
+        write_command::{Insert, Operation},
+        WriteCommand,
+    },
+    common::{entry_payload::Payload, Entry, EntryPayload},
+    LogStore, Result, StorageEngine,
 };
 use prost::Message;
 use std::sync::Arc;
@@ -13,45 +15,60 @@ use tracing::debug;
 use tracing_test::traced_test;
 use uuid::Uuid;
 
+/// Helper for building temporary sled storage engines for testing
 pub struct SledStorageEngineBuilder {
     temp_dir: TempDir,
 }
 
 impl SledStorageEngineBuilder {
+    /// Creates a new builder with a temporary directory
     pub fn new() -> Self {
         let temp_dir = TempDir::new().unwrap();
         Self { temp_dir }
     }
-}
-
-#[async_trait]
-impl StorageEngineBuilder for SledStorageEngineBuilder {
-    type Engine = SledStorageEngine;
 
-    async fn build(&self) -> Result<Arc<Self::Engine>, Error> {
+    /// Builds a new storage engine instance
+    pub async fn build(&self) -> Result<Arc<SledStorageEngine>> {
         let unique_path = format!("sled_{}", Uuid::new_v4());
         let path = self.temp_dir.path().join(unique_path);
-
         let engine = SledStorageEngine::new(path, 1)?;
         Ok(Arc::new(engine))
     }
-
-    async fn cleanup(&self) -> Result<(), Error> {
-        // TempDir will be cleaned up automatically when dropped
-        Ok(())
-    }
 }
 
 #[tokio::test]
 #[traced_test]
-async fn test_sled_storage_engine() -> Result<(), Error> {
+async fn test_sled_storage_engine_basic() -> Result<()> {
     let builder = SledStorageEngineBuilder::new();
-    StorageEngineTestSuite::run_all_tests(builder).await
+    let engine = builder.build().await?;
+    let log_store = engine.log_store();
+
+    // Basic test: persist a few entries
+    let entries = vec![
+        Entry {
+            index: 1,
+            term: 1,
+            payload: Some(create_test_command_payload(1)),
+        },
+        Entry {
+            index: 2,
+            term: 1,
+            payload: Some(create_test_command_payload(2)),
+        },
+    ];
+
+    log_store.persist_entries(entries).await?;
+
+    // Verify entries can be retrieved
+    let retrieved = log_store.entry(1).await?;
+    assert!(retrieved.is_some(), "Entry 1 should exist");
+
+    Ok(())
 }
 
 #[tokio::test]
 #[traced_test]
-async fn test_sled_performance() -> Result<(), Error> {
+async fn test_sled_performance() -> Result<()> {
     let builder = SledStorageEngineBuilder::new();
     let engine = builder.build().await?;
     let log_store = engine.log_store();
@@ -61,7 +78,7 @@ async fn test_sled_performance() -> Result<(), Error> {
     let entries = (1..=10000)
         .map(|i| Entry {
             index: i,
-            term: i,
+            term: 1,
             payload: Some(create_test_command_payload(i)),
         })
         .collect();
@@ -71,31 +88,29 @@ async fn test_sled_performance() -> Result<(), Error> {
 
     debug!("Persisted 10,000 entries in {duration:?}");
     assert!(
-        duration.as_millis() < 1000,
-        "Should persist 10k entries in <1s"
+        duration.as_millis() < 5000,
+        "Should persist 10k entries in <5s"
     );
 
-    builder.cleanup().await?;
     Ok(())
 }
 
-fn create_test_command_payload(index: u64) -> d_engine::proto::common::EntryPayload {
-    // Create a simple insert command
+/// Helper function to create a test command payload
+fn create_test_command_payload(index: u64) -> EntryPayload {
     let key = Bytes::from(format!("key_{index}").into_bytes());
     let value = Bytes::from(format!("value_{index}").into_bytes());
 
     let insert = Insert { key, value };
-    let operation = d_engine::proto::client::write_command::Operation::Insert(insert);
-    let write_cmd = d_engine::proto::client::WriteCommand {
+    let operation = Operation::Insert(insert);
+    let write_cmd = WriteCommand {
         operation: Some(operation),
     };
 
     let mut buffer = BytesMut::new();
     write_cmd.encode(&mut buffer).expect("Failed to encode insert command");
     let buffer = buffer.freeze();
-    d_engine::proto::common::EntryPayload {
-        payload: Some(d_engine::proto::common::entry_payload::Payload::Command(
-            buffer,
-        )),
+
+    EntryPayload {
+        payload: Some(Payload::Command(buffer)),
     }
 }
diff --git a/examples/sled-cluster/src/sled_state_machine.rs b/examples/sled-cluster/src/sled_state_machine.rs
index 3b54e4cf..b3f8b95f 100644
--- a/examples/sled-cluster/src/sled_state_machine.rs
+++ b/examples/sled-cluster/src/sled_state_machine.rs
@@ -4,20 +4,15 @@ use arc_swap::ArcSwap;
 use async_trait::async_trait;
 use bincode::config;
 use bytes::Bytes;
-use d_engine::convert::safe_kv;
-use d_engine::convert::safe_vk;
-use d_engine::proto::client::write_command::Delete;
-use d_engine::proto::client::write_command::Insert;
-use d_engine::proto::client::write_command::Operation;
-use d_engine::proto::client::WriteCommand;
-use d_engine::proto::common::entry_payload::Payload;
-use d_engine::proto::common::Entry;
-use d_engine::proto::common::LogId;
-use d_engine::proto::storage::SnapshotMetadata;
-use d_engine::Error;
-use d_engine::SnapshotError;
-use d_engine::StateMachine;
-use d_engine::StorageError;
+use d_engine::{
+    common::{entry_payload::Payload, Entry, LogId},
+    storage::SnapshotMetadata,
+    write_command::{
+        write_command::{Delete, Insert, Operation},
+        WriteCommand,
+    },
+    Result, SnapshotError, StateMachine, StorageError,
+};
 use parking_lot::Mutex;
 use prost::Message;
 use sled::Batch;
@@ -37,6 +32,7 @@ use tracing::trace;
 use tracing::warn;
 
 use crate::compute_checksum_from_folder_path;
+use crate::{safe_kv, safe_vk, safe_vk_ivec};
 
 /// Sled database tree namespaces
 pub(crate) const STATE_MACHINE_TREE: &str = "_state_machine_tree";
@@ -97,13 +93,13 @@ impl Drop for SledStateMachine {
 
 #[async_trait]
 impl StateMachine for SledStateMachine {
-    fn start(&self) -> Result<(), Error> {
+    fn start(&self) -> Result<()> {
         debug!("start state machine");
         self.is_serving.store(true, Ordering::Release);
         Ok(())
     }
 
-    fn stop(&self) -> Result<(), Error> {
+    fn stop(&self) -> Result<()> {
         debug!("stop state machine");
         self.is_serving.store(false, Ordering::Release);
         Ok(())
@@ -125,12 +121,15 @@ impl StateMachine for SledStateMachine {
     fn update_last_snapshot_metadata(
         &self,
         snapshot_metadata: &SnapshotMetadata,
-    ) -> Result<(), Error> {
+    ) -> Result<()> {
         debug!(%self.node_id, ?snapshot_metadata, "update_last_snapshot_metadata");
         let last_included = snapshot_metadata.last_included.unwrap();
         self.last_included_index.store(last_included.index, Ordering::SeqCst);
         self.last_included_term.store(last_included.term, Ordering::SeqCst);
-        *self.last_snapshot_checksum.lock() = Some(snapshot_metadata.checksum_array()?);
+        let checksum = snapshot_metadata
+            .checksum_array()
+            .map_err(|e| SnapshotError::OperationFailed(format!("{e:?}")))?;
+        *self.last_snapshot_checksum.lock() = Some(checksum);
 
         Ok(())
     }
@@ -164,7 +163,7 @@ impl StateMachine for SledStateMachine {
     fn get(
         &self,
         key_buffer: &[u8],
-    ) -> Result<Option<Bytes>, Error> {
+    ) -> Result<Option<Bytes>> {
         match self.current_tree().get(key_buffer) {
             Ok(Some(v)) => Ok(Some(Bytes::copy_from_slice(&v))),
             Ok(None) => Ok(None),
@@ -192,7 +191,7 @@ impl StateMachine for SledStateMachine {
     async fn apply_chunk(
         &self,
         chunk: Vec<Entry>,
-    ) -> Result<(), Error> {
+    ) -> Result<()> {
         trace!("Applying chunk: {:?}.", chunk);
 
         let mut highest_index_entry: Option<LogId> = None;
@@ -280,7 +279,7 @@ impl StateMachine for SledStateMachine {
         Ok(())
     }
 
-    fn save_hard_state(&self) -> Result<(), Error> {
+    fn save_hard_state(&self) -> Result<()> {
         let last_applied = self.last_applied();
         self.persist_last_applied(last_applied)?;
 
@@ -295,7 +294,7 @@ impl StateMachine for SledStateMachine {
     fn persist_last_applied(
         &self,
         last_applied: LogId,
-    ) -> Result<(), Error> {
+    ) -> Result<()> {
         debug!(%self.node_id, ?last_applied, "persist_last_applied");
         let db = self.db.load();
         let tree = db
@@ -303,12 +302,12 @@ impl StateMachine for SledStateMachine {
             .map_err(|e| StorageError::DbError(e.to_string()))?;
         tree.insert(
             STATE_MACHINE_META_KEY_LAST_APPLIED_INDEX,
-            &safe_kv(last_applied.index),
+            safe_kv(last_applied.index),
         )
         .map_err(|e| StorageError::DbError(e.to_string()))?;
         tree.insert(
             STATE_MACHINE_META_KEY_LAST_APPLIED_TERM,
-            &safe_kv(last_applied.term),
+            safe_kv(last_applied.term),
         )
         .map_err(|e| StorageError::DbError(e.to_string()))?;
 
@@ -319,7 +318,7 @@ impl StateMachine for SledStateMachine {
     fn persist_last_snapshot_metadata(
         &self,
         last_snapshot_metadata: &SnapshotMetadata,
-    ) -> Result<(), Error> {
+    ) -> Result<()> {
         debug!(%self.node_id, ?last_snapshot_metadata, "persist_last_snapshot_metadata");
         let db = self.db.load();
         let tree = db
@@ -330,7 +329,7 @@ impl StateMachine for SledStateMachine {
         Ok(())
     }
 
-    fn flush(&self) -> Result<(), Error> {
+    fn flush(&self) -> Result<()> {
         let db = self.db.load();
         match db.flush() {
             Ok(bytes) => {
@@ -348,7 +347,7 @@ impl StateMachine for SledStateMachine {
         Ok(())
     }
 
-    async fn flush_async(&self) -> Result<(), Error> {
+    async fn flush_async(&self) -> Result<()> {
         self.flush()
     }
 
@@ -357,7 +356,7 @@ impl StateMachine for SledStateMachine {
         &self,
         new_snapshot_dir: PathBuf,
         last_included: LogId,
-    ) -> Result<Bytes, Error> {
+    ) -> Result<Bytes> {
         // 1. Get a lightweight write lock (to prevent concurrent snapshot generation)
         let _guard = self.snapshot_lock.write().await;
 
@@ -379,7 +378,7 @@ impl StateMachine for SledStateMachine {
                 Ok(v) => v,
                 Err(e) => {
                     error!(?e, "generate_snapshot_data::safe_vk");
-                    return Err(e);
+                    return Err(e.into());
                 }
             };
             if key_num > last_included.index {
@@ -437,7 +436,7 @@ impl StateMachine for SledStateMachine {
         &self,
         metadata: &SnapshotMetadata,
         decompressed_snapshot_path: PathBuf,
-    ) -> Result<(), Error> {
+    ) -> Result<()> {
         if let Some(new_last_included) = metadata.last_included {
             debug!(
                 ?new_last_included,
@@ -521,7 +520,7 @@ impl StateMachine for SledStateMachine {
         self.current_tree().len()
     }
 
-    async fn reset(&self) -> Result<(), Error> {
+    async fn reset(&self) -> Result<()> {
         let db = self.db.load();
         db.clear().map_err(|e| StorageError::DbError(e.to_string()))?;
         Ok(())
@@ -532,7 +531,7 @@ impl SledStateMachine {
     pub fn new<P: AsRef<Path> + std::fmt::Debug>(
         path: P,
         node_id: u32,
-    ) -> Result<Self, Error> {
+    ) -> Result<Self> {
         let db = Arc::new(
             init_sled_state_machine_db(path).map_err(|e| StorageError::DbError(e.to_string()))?,
         );
@@ -582,25 +581,23 @@ impl SledStateMachine {
         Ok(sm)
     }
 
-    fn load_state_machine_metadata(tree: &sled::Tree) -> Result<(u64, u64), Error> {
+    fn load_state_machine_metadata(tree: &sled::Tree) -> Result<(u64, u64)> {
         let index = tree
             .get(STATE_MACHINE_META_KEY_LAST_APPLIED_INDEX)
             .map_err(|e| StorageError::DbError(e.to_string()))?
-            .map(safe_vk)
+            .map(safe_vk_ivec)
             .unwrap_or(Ok(0))?;
 
         let term = tree
             .get(STATE_MACHINE_META_KEY_LAST_APPLIED_TERM)
             .map_err(|e| StorageError::DbError(e.to_string()))?
-            .map(safe_vk)
+            .map(safe_vk_ivec)
             .unwrap_or(Ok(0))?;
 
         Ok((index, term))
     }
 
-    pub(super) fn load_snapshot_metadata(
-        tree: &sled::Tree
-    ) -> Result<Option<SnapshotMetadata>, Error> {
+    pub(super) fn load_snapshot_metadata(tree: &sled::Tree) -> Result<Option<SnapshotMetadata>> {
         if let Ok(Some(v)) = tree.get(LAST_SNAPSHOT_METADATA_KEY) {
             info!(
                 "found SnapshotMetadata from DB with key: {}",
@@ -631,7 +628,7 @@ impl SledStateMachine {
     pub(super) fn apply_batch(
         &self,
         batch: Batch,
-    ) -> Result<(), Error> {
+    ) -> Result<()> {
         if let Err(e) = self.current_tree().apply_batch(batch) {
             error!("state_machine apply_batch failed: {}", e);
             return Err(StorageError::DbError(e.to_string()).into());
@@ -650,7 +647,7 @@ impl SledStateMachine {
         &self,
         tree: sled::Tree,
         last_snapshot_metadata: &SnapshotMetadata,
-    ) -> Result<(), Error> {
+    ) -> Result<()> {
         let config = config::standard();
         let v = bincode::serde::encode_to_vec(last_snapshot_metadata, config)
             .map_err(|e| StorageError::DbError(e.to_string()))?;
@@ -668,14 +665,14 @@ impl SledStateMachine {
 fn new_tree(
     db: &sled::Db,
     key: &str,
-) -> Result<sled::Tree, Error> {
+) -> Result<sled::Tree> {
     db.open_tree(key)
         .map_err(|e| SnapshotError::OperationFailed(format!("{e:?}")).into())
 }
 
 pub fn init_sled_state_machine_db(
     sled_db_root_path: impl AsRef<std::path::Path> + std::fmt::Debug
-) -> Result<sled::Db, sled::Error> {
+) -> std::result::Result<sled::Db, sled::Error> {
     tracing::debug!(
         "init_sled_state_machine_db from path: {:?}",
         sled_db_root_path
diff --git a/examples/sled-cluster/src/sled_storage_engine.rs b/examples/sled-cluster/src/sled_storage_engine.rs
index 3c56a059..85c7c986 100644
--- a/examples/sled-cluster/src/sled_storage_engine.rs
+++ b/examples/sled-cluster/src/sled_storage_engine.rs
@@ -1,16 +1,10 @@
 use async_trait::async_trait;
 use bincode::config;
 use bytes::Bytes;
-use d_engine::convert::safe_vk;
-use d_engine::proto::common::Entry;
-use d_engine::proto::common::LogId;
-use d_engine::Error;
-use d_engine::HardState;
-use d_engine::LogStore;
-use d_engine::MetaStore;
-use d_engine::ProstError;
-use d_engine::StorageEngine;
-use d_engine::StorageError;
+use d_engine::{
+    common::{Entry, LogId},
+    Error, HardState, LogStore, MetaStore, ProstError, Result, StorageEngine, StorageError,
+};
 use prost::Message;
 use sled::Batch;
 use sled::IVec;
@@ -62,7 +56,7 @@ impl LogStore for SledLogStore {
     async fn persist_entries(
         &self,
         entries: Vec<Entry>,
-    ) -> Result<(), Error> {
+    ) -> Result<()> {
         let mut batch = Batch::default();
         let mut max_index = 0;
 
@@ -84,7 +78,7 @@ impl LogStore for SledLogStore {
     async fn entry(
         &self,
         index: u64,
-    ) -> Result<Option<Entry>, Error> {
+    ) -> Result<Option<Entry>> {
         let key = SledStorageEngine::index_to_key(index);
         match self.tree.get(key).map_err(|e| StorageError::DbError(e.to_string()))? {
             Some(bytes) => {
@@ -99,7 +93,7 @@ impl LogStore for SledLogStore {
     fn get_entries(
         &self,
         range: RangeInclusive<u64>,
-    ) -> Result<Vec<Entry>, Error> {
+    ) -> Result<Vec<Entry>> {
         let start = SledStorageEngine::index_to_key(*range.start());
         let end = SledStorageEngine::index_to_key(*range.end());
         let mut entries = Vec::new();
@@ -117,7 +111,7 @@ impl LogStore for SledLogStore {
     async fn purge(
         &self,
         cutoff_index: LogId,
-    ) -> Result<(), Error> {
+    ) -> Result<()> {
         let start = SledStorageEngine::index_to_key(0);
         let end = SledStorageEngine::index_to_key(cutoff_index.index);
         let mut batch = Batch::default();
@@ -135,7 +129,7 @@ impl LogStore for SledLogStore {
     async fn truncate(
         &self,
         from_index: u64,
-    ) -> Result<(), Error> {
+    ) -> Result<()> {
         let start_key = SledStorageEngine::index_to_key(from_index);
         let mut batch = Batch::default();
 
@@ -149,13 +143,13 @@ impl LogStore for SledLogStore {
     }
 
     #[instrument(skip(self))]
-    fn flush(&self) -> Result<(), Error> {
+    fn flush(&self) -> Result<()> {
         trace!("LogStore flush");
         self.tree.flush().map_err(|e| StorageError::DbError(e.to_string()))?;
         Ok(())
     }
 
-    async fn flush_async(&self) -> Result<(), Error> {
+    async fn flush_async(&self) -> Result<()> {
         trace!("LogStore flush");
         self.tree
             .flush_async()
@@ -165,7 +159,7 @@ impl LogStore for SledLogStore {
     }
 
     #[instrument(skip(self))]
-    async fn reset(&self) -> Result<(), Error> {
+    async fn reset(&self) -> Result<()> {
         self.tree.clear().map_err(|e| StorageError::DbError(e.to_string()))?;
         Ok(())
     }
@@ -173,13 +167,16 @@ impl LogStore for SledLogStore {
     #[instrument(skip(self))]
     fn last_index(&self) -> u64 {
         match self.tree.last() {
-            Ok(Some((key, _))) => match safe_vk(&key) {
-                Ok(index) => index,
-                Err(err) => {
-                    tracing::warn!("Invalid key format in sled: {:?}", err);
+            Ok(Some((key, _))) => {
+                if key.len() >= 8 {
+                    let mut bytes = [0u8; 8];
+                    bytes.copy_from_slice(&key[0..8]);
+                    u64::from_be_bytes(bytes)
+                } else {
+                    tracing::warn!("Invalid key format in sled: key too short");
                     0
                 }
-            },
+            }
             _ => 0,
         }
     }
@@ -190,7 +187,7 @@ impl MetaStore for SledMetaStore {
     fn save_hard_state(
         &self,
         state: &HardState,
-    ) -> Result<(), Error> {
+    ) -> Result<()> {
         let config = config::standard();
         match bincode::serde::encode_to_vec(state, config) {
             Ok(v) => {
@@ -219,7 +216,7 @@ impl MetaStore for SledMetaStore {
         Ok(())
     }
 
-    fn load_hard_state(&self) -> Result<Option<HardState>, Error> {
+    fn load_hard_state(&self) -> Result<Option<HardState>> {
         info!(
             "pending load_role_hard_state_from_db with key: {:?}",
             HARD_STATE_KEY
@@ -262,12 +259,12 @@ impl MetaStore for SledMetaStore {
         }
     }
 
-    fn flush(&self) -> Result<(), Error> {
+    fn flush(&self) -> Result<()> {
         self.tree.flush().map_err(|e| StorageError::DbError(e.to_string()))?;
         Ok(())
     }
 
-    async fn flush_async(&self) -> Result<(), Error> {
+    async fn flush_async(&self) -> Result<()> {
         trace!("MetaStore flush");
         self.tree
             .flush_async()
@@ -307,7 +304,7 @@ impl SledStorageEngine {
     pub fn new<P: AsRef<Path> + std::fmt::Debug>(
         path: P,
         node_id: u32,
-    ) -> Result<Self, Error> {
+    ) -> Result<Self> {
         let (log_tree, meta_tree) = init_sled_log_tree_and_meta_tree(path, node_id)
             .map_err(|e| StorageError::DbError(e.to_string()))?;
 
@@ -344,7 +341,7 @@ impl SledLogStore {
         &self,
         key: K,
         value: V,
-    ) -> Result<Option<Vec<u8>>, Error>
+    ) -> Result<Option<Vec<u8>>>
     where
         K: AsRef<[u8]> + 'static,
         V: AsRef<[u8]> + 'static,
@@ -363,7 +360,7 @@ impl SledLogStore {
     pub fn get<K>(
         &self,
         key: K,
-    ) -> Result<Option<Bytes>, Error>
+    ) -> Result<Option<Bytes>>
     where
         K: AsRef<[u8]> + Send + 'static,
     {
@@ -390,7 +387,7 @@ impl SledMetaStore {
         &self,
         key: K,
         value: V,
-    ) -> Result<Option<Vec<u8>>, Error>
+    ) -> Result<Option<Vec<u8>>>
     where
         K: AsRef<[u8]> + 'static,
         V: AsRef<[u8]> + 'static,
@@ -409,7 +406,7 @@ impl SledMetaStore {
     pub fn get<K>(
         &self,
         key: K,
-    ) -> Result<Option<Bytes>, Error>
+    ) -> Result<Option<Bytes>>
     where
         K: AsRef<[u8]> + Send + 'static,
     {
@@ -433,7 +430,7 @@ impl SledMetaStore {
 pub fn init_sled_log_tree_and_meta_tree(
     sled_db_root_path: impl AsRef<std::path::Path> + std::fmt::Debug,
     node_id: u32,
-) -> Result<(sled::Tree, sled::Tree), sled::Error> {
+) -> std::result::Result<(sled::Tree, sled::Tree), sled::Error> {
     let db = init_sled_storage_engine_db(&sled_db_root_path)?;
     let log_tree_name = format!("raft_log_{RAFT_LOG_NAMESPACE}_{node_id}");
     let meta_tree_name = format!("raft_meta_{RAFT_META_NAMESPACE}_{node_id}");
@@ -445,7 +442,7 @@ pub fn init_sled_log_tree_and_meta_tree(
 
 pub fn init_sled_storage_engine_db(
     sled_db_root_path: impl AsRef<std::path::Path> + std::fmt::Debug
-) -> Result<sled::Db, sled::Error> {
+) -> std::result::Result<sled::Db, sled::Error> {
     tracing::debug!(
         "init_sled_storage_engine_db from path: {:?}",
         &sled_db_root_path
diff --git a/examples/sled-cluster/src/state_machine/sled_state_machine_test.rs b/examples/sled-cluster/src/state_machine/sled_state_machine_test.rs
index bc3e6771..9a2484c1 100644
--- a/examples/sled-cluster/src/state_machine/sled_state_machine_test.rs
+++ b/examples/sled-cluster/src/state_machine/sled_state_machine_test.rs
@@ -15,15 +15,15 @@ use d_engine::convert::safe_kv;
 use d_engine::file_io::compute_checksum_from_folder_path;
 use d_engine::init_sled_state_machine_db;
 use d_engine::init_sled_storages;
-use d_engine::proto::common::Entry;
-use d_engine::proto::common::EntryPayload;
-use d_engine::proto::common::LogId;
-use d_engine::proto::storage::SnapshotMetadata;
 use d_engine::test_utils::generate_delete_commands;
 use d_engine::test_utils::generate_insert_commands;
 use d_engine::test_utils::reset_dbs;
 use d_engine::test_utils::reuse_dbs;
 use d_engine::StateMachine;
+use d_engine::common::Entry;
+use d_engine::common::EntryPayload;
+use d_engine::common::LogId;
+use d_engine::storage::SnapshotMetadata;
 
 pub fn setup_raft_components(
     db_path: &str,
diff --git a/examples/sled-cluster/src/storage_engine/sled_storage_engine_test.rs b/examples/sled-cluster/src/storage_engine/sled_storage_engine_test.rs
index 07debe51..d33ea1a8 100644
--- a/examples/sled-cluster/src/storage_engine/sled_storage_engine_test.rs
+++ b/examples/sled-cluster/src/storage_engine/sled_storage_engine_test.rs
@@ -1,8 +1,4 @@
 use super::*;
-use d_engine::proto::common::Entry;
-use d_engine::proto::common::EntryPayload;
-use d_engine::proto::common::LogId;
-use d_engine::proto::election::VotedFor;
 use d_engine::Error;
 use d_engine::HardState;
 use d_engine::LogStore;
@@ -10,6 +6,10 @@ use d_engine::MetaStore;
 use d_engine::ProstError;
 use d_engine::StorageEngine;
 use d_engine::SystemError;
+use d_engine::common::Entry;
+use d_engine::common::EntryPayload;
+use d_engine::common::LogId;
+use d_engine::election::VotedFor;
 use std::ops::RangeInclusive;
 use std::sync::Arc;
 use tempfile::TempDir;
diff --git a/examples/three-nodes-cluster/Cargo.toml b/examples/three-nodes-cluster/Cargo.toml
index 0e02c396..b7953eba 100644
--- a/examples/three-nodes-cluster/Cargo.toml
+++ b/examples/three-nodes-cluster/Cargo.toml
@@ -4,8 +4,8 @@ version = "0.1.4"
 edition = "2021"
 
 [dependencies]
+d-engine = { path = "../../d-engine", features = ["server", "rocksdb"] }
 # d-engine = "0.1.1"
-d-engine = { path = "../../../d-engine", features = ["rocksdb"] }
 # d-engine = { git = "https://github.com/deventlab/d-engine.git", branch = "feature/79-snapshot" }
 
 metrics-exporter-prometheus = "0.17.2"
diff --git a/examples/three-nodes-cluster/src/main.rs b/examples/three-nodes-cluster/src/main.rs
index 3e075a92..31d82088 100644
--- a/examples/three-nodes-cluster/src/main.rs
+++ b/examples/three-nodes-cluster/src/main.rs
@@ -1,11 +1,11 @@
-use d_engine::file_io::open_file_for_append;
-use d_engine::node::NodeBuilder;
+use d_engine::NodeBuilder;
 // use d_engine::FileStateMachine;
 // use d_engine::FileStorageEngine;
 use d_engine::RocksDBStateMachine;
 use d_engine::RocksDBStorageEngine;
 use std::env;
 use std::error::Error;
+use std::fs::OpenOptions;
 use std::path::Path;
 use std::path::PathBuf;
 use std::sync::Arc;
@@ -190,3 +190,16 @@ async fn collect_tokio_metrics(
         }
     }
 }
+
+fn open_file_for_append(path: PathBuf) -> Result<std::fs::File, Box<dyn Error>> {
+    // Create parent directories if they don't exist
+    if let Some(parent) = path.parent() {
+        if parent != Path::new("") {
+            std::fs::create_dir_all(parent)?;
+        }
+    }
+
+    let log_file = OpenOptions::new().append(true).create(true).open(&path)?;
+
+    Ok(log_file)
+}
diff --git a/scripts/pre-release-checklist.sh b/scripts/pre-release-checklist.sh
deleted file mode 100755
index bff51705..00000000
--- a/scripts/pre-release-checklist.sh
+++ /dev/null
@@ -1,132 +0,0 @@
-#!/usr/bin/env bash
-# pre-release-checklist.sh
-set -euxo pipefail
-
-# Add color output
-RED='\033[0;31m'
-GREEN='\033[0;32m'
-YELLOW='\033[1;33m'
-NC='\033[0m' # No Color
-
-function header() {
-    echo -e "${YELLOW}\n==> $1${NC}"
-}
-
-function success() {
-    echo -e "${GREEN}[✓] $1${NC}"
-}
-
-function error() {
-    echo -e "${RED}[✗] $1${NC}"
-    exit 1
-}
-
-# --------------------------
-# 1. Test Suite Verification
-# --------------------------
-header "Running test suite"
-
-TEST_TYPES=(
-    "Unit Tests: cargo test --lib -- --nocapture"
-    "Integration Tests: cargo test --tests -- --nocapture"
-    "Documentation Tests: cargo test --doc"
-    "Benchmark Tests: cargo bench -- --nocapture"
-)
-
-for test_case in "${TEST_TYPES[@]}"; do
-    IFS=':' read -r test_name test_cmd <<< "$test_case"
-    echo -e "\n${YELLOW}▶ Running $test_name${NC}"
-    
-    if eval "$test_cmd"; then
-        success "$test_name passed"
-    else
-        error "$test_name failed"
-    fi
-done
-
-# --------------------------
-# Final Report
-# --------------------------
-header "Test Summary"
-echo -e "${GREEN}All checks passed! Ready for release.${NC}"
-
-
-# --------------------------
-# 2. Code quality checks
-# --------------------------
-header "Running code quality checks"
-cargo clippy --all-targets --all-features -- -D warnings || error "Clippy found issues"
-cargo fmt --all -- --check || error "Code formatting issues found"
-
-
-# --------------------------
-# 3. CHANGELOG reminder
-# --------------------------
-header "Checking CHANGELOG updates"
-if git diff --exit-code --name-only CHANGELOG.md; then
-    success "No changes detected in CHANGELOG.md."
-else
-    success "CHANGELOG.md is updated"
-fi
-
-# # --------------------------
-# # 4. 3-node cluster example test
-# # --------------------------
-# header "Testing 3-node cluster example"
-# (
-#     cd examples/three-nodes-cluster || error "Cluster example directory not found"
-
-#     # Clean previous runs
-#     make clean
-
-#     # Start the cluster and capture logs
-#     LOG_FILE="logs/leader_detection.log"
-#     mkdir -p logs
-#     make start-cluster > "$LOG_FILE" 2>&1 &
-#     CLUSTER_PID=$!
-
-#     # Set the detection timeout (in seconds)
-#     TIMEOUT=30
-#     LEADER_DETECTED=0
-
-#     # Real-time monitoring log
-#     timeout $TIMEOUTs tail -Fn0 "$LOG_FILE" | \
-#     while read -r line
-#     do
-#         if echo "$line" | grep -q "switch to Leader now."; then
-#             LEADER_DETECTED=1
-
-#             # Get and terminate all demo processes
-#             pids=$(pgrep -f "target/release/demo")
-#             if [ -n "$pids" ]; then
-#                 echo "Killing demo processes: $pids"
-#                 kill $pids
-#             fi
-
-#             # Terminate the log monitoring loop
-#             pkill -P $$ timeout
-#             break
-#         fi
-#     done
-
-#     # Handling timeouts
-#     if [ $LEADER_DETECTED -eq 0 ]; then
-#         error "Leader not detected within $TIMEOUT seconds"
-#     fi
-
-#     # Wait for the cluster process to exit
-#     wait $CLUSTER_PID
-
-#     # Verify that the process has terminated
-#     if pgrep -f "target/release/demo" >/dev/null; then
-#         error "Failed to kill all demo processes"
-#     fi
-
-#     success "Cluster test passed"
-# ) || error "Cluster test failed"
-
-
-# --------------------------
-# All checks passed
-# --------------------------
-echo -e "${GREEN}\nAll pre-release checks passed! Ready for deployment.${NC}"
\ No newline at end of file
diff --git a/src/client/mod.rs b/src/client/mod.rs
deleted file mode 100644
index 2226d4d9..00000000
--- a/src/client/mod.rs
+++ /dev/null
@@ -1,339 +0,0 @@
-//! Client module for distributed consensus system
-//!
-//! Provides core components for interacting with the d_engine cluster:
-//! - [`Client`] - Main entry point with cluster access
-//! - [`ClientBuilder`] - Configurable client construction
-//! - [`KvClient`] - Key-value store operations
-//! - [`ClusterClient`] - Cluster management operations
-//! - [`ConnectionPool`] - Underlying connection management
-//!
-//! # Basic Usage
-//! ```no_run
-//! use d_engine::client::{Client, ClientBuilder};
-//! use std::time::Duration;
-//! use core::error::Error;
-//!
-//! #[tokio::main(flavor = "current_thread")]
-//! async fn main(){
-//!     // Initialize client with automatic cluster discovery
-//!     let client = Client::builder(vec![
-//!         "http://node1:9081".into(),
-//!         "http://node2:9082".into()
-//!     ])
-//!     .connect_timeout(Duration::from_secs(3))
-//!     .request_timeout(Duration::from_secs(1))
-//!     .enable_compression(true)
-//!     .build()
-//!     .await
-//!     .unwrap();
-//!
-//!     // Execute key-value operations
-//!     client.kv().put("user:1001", "Alice").await.unwrap();
-//!
-//!     let value = client.kv().get("user:1001").await.unwrap();
-//!
-//!     println!("User data: {:?}", value);
-//!
-//!     // Perform cluster management
-//!     let members = client.cluster().list_members().await.unwrap();
-//!     println!("Cluster members: {:?}", members);
-//!
-//! }
-//! ```
-
-mod builder;
-mod cluster;
-mod config;
-mod error;
-mod kv;
-mod pool;
-
-pub use builder::*;
-use bytes::Bytes;
-pub use cluster::*;
-pub use config::*;
-pub use error::*;
-pub use kv::*;
-pub use pool::*;
-
-#[cfg(test)]
-mod cluster_test;
-#[cfg(test)]
-mod kv_test;
-#[cfg(test)]
-mod pool_test;
-
-use std::sync::Arc;
-
-use arc_swap::ArcSwap;
-use tracing::error;
-
-use crate::proto::client::client_response::SuccessResult;
-use crate::proto::client::write_command;
-use crate::proto::client::ClientResponse;
-use crate::proto::client::ClientResult;
-use crate::proto::client::ReadResults;
-use crate::proto::client::WriteCommand;
-use crate::proto::error::ErrorCode;
-
-/// Main entry point for interacting with the d_engine cluster
-///
-/// Manages connections and provides access to specialized clients:
-/// - Use [`kv()`](Client::kv) for data operations
-/// - Use [`cluster()`](Client::cluster) for cluster administration
-///
-/// Created through the [`builder()`](Client::builder) method
-#[derive(Clone)]
-pub struct Client {
-    /// Key-value store client interface
-    pub(super) kv: KvClient,
-
-    /// Cluster management client interface
-    pub(super) cluster: ClusterClient,
-
-    pub(super) inner: Arc<ArcSwap<ClientInner>>,
-}
-
-#[derive(Clone)]
-pub struct ClientInner {
-    pub(super) pool: ConnectionPool,
-    pub(super) client_id: u32,
-    pub(super) config: ClientConfig,
-    pub(super) endpoints: Vec<String>,
-}
-
-impl Client {
-    /// Access the key-value operations client
-    ///
-    /// # Examples
-    /// ```rust,ignore
-    /// client.kv().put("key", "value").await?;
-    /// ```
-    pub fn kv(&self) -> &KvClient {
-        &self.kv
-    }
-
-    /// Access the cluster management client
-    ///
-    /// # Examples
-    /// ```rust,ignore
-    /// client.cluster().add_node("node3:9083").await?;
-    /// ```
-    pub fn cluster(&self) -> &ClusterClient {
-        &self.cluster
-    }
-
-    /// Create a configured client builder
-    ///
-    /// Starts client construction process with specified bootstrap endpoints.
-    /// Chain configuration methods before calling
-    /// [`build()`](ClientBuilder::build).
-    ///
-    /// # Arguments
-    /// * `endpoints` - Initial cluster nodes for discovery
-    ///
-    /// # Panics
-    /// Will panic if no valid endpoints provided
-    pub fn builder(endpoints: Vec<String>) -> ClientBuilder {
-        assert!(!endpoints.is_empty(), "At least one endpoint required");
-        ClientBuilder::new(endpoints)
-    }
-
-    pub async fn refresh(
-        &mut self,
-        new_endpoints: Option<Vec<String>>,
-    ) -> std::result::Result<(), ClientApiError> {
-        // Get a writable lock
-        let old_inner = self.inner.load();
-        let config = old_inner.config.clone();
-        let endpoints = new_endpoints.unwrap_or(old_inner.endpoints.clone());
-
-        let new_pool = ConnectionPool::create(endpoints.clone(), config.clone()).await?;
-
-        let new_inner = Arc::new(ClientInner {
-            pool: new_pool,
-            client_id: old_inner.client_id,
-            config,
-            endpoints,
-        });
-
-        self.inner.store(new_inner);
-        Ok(())
-    }
-}
-
-impl WriteCommand {
-    /// Create write command for key-value pair
-    ///
-    /// # Parameters
-    /// - `key`: Byte array for storage key
-    /// - `value`: Byte array to be stored
-    pub fn insert(
-        key: impl Into<Bytes>,
-        value: impl Into<Bytes>,
-    ) -> Self {
-        let cmd = write_command::Insert {
-            key: key.into(),
-            value: value.into(),
-        };
-        Self {
-            operation: Some(write_command::Operation::Insert(cmd)),
-        }
-    }
-
-    /// Create deletion command for specified key
-    ///
-    /// # Parameters
-    /// - `key`: Byte array of key to delete
-    pub fn delete(key: impl Into<Bytes>) -> Self {
-        let cmd = write_command::Delete { key: key.into() };
-        Self {
-            operation: Some(write_command::Operation::Delete(cmd)),
-        }
-    }
-}
-impl ClientResponse {
-    /// Build success response for write operations
-    ///
-    /// # Returns
-    /// Response with NoError code and write confirmation
-    pub fn write_success() -> Self {
-        Self {
-            error: ErrorCode::Success as i32,
-            success_result: Some(SuccessResult::WriteAck(true)),
-            metadata: None,
-        }
-    }
-
-    /// Check if the write operation was successful
-    ///
-    /// # Returns
-    /// - `true` if the response indicates a successful write operation
-    /// - `false` if the response indicates a failed write operation or is not a write response
-    pub fn is_write_success(&self) -> bool {
-        self.error == ErrorCode::Success as i32
-            && matches!(self.success_result, Some(SuccessResult::WriteAck(true)))
-    }
-
-    /// Build success response for read operations
-    ///
-    /// # Parameters
-    /// - `results`: Vector of retrieved key-value pairs
-    pub fn read_results(results: Vec<ClientResult>) -> Self {
-        Self {
-            error: ErrorCode::Success as i32,
-            success_result: Some(SuccessResult::ReadData(ReadResults { results })),
-            metadata: None,
-        }
-    }
-
-    /// Build generic error response for any operation type
-    ///
-    /// # Parameters
-    /// - `error_code`: Predefined client request error code
-    pub fn client_error(error_code: ErrorCode) -> Self {
-        Self {
-            error: error_code as i32,
-            success_result: None,
-            metadata: None,
-        }
-    }
-
-    /// Convert response to boolean write result
-    ///
-    /// # Returns
-    /// - `Ok(true)` on successful write
-    /// - `Err` with converted error code on failure
-    pub fn into_write_result(&self) -> std::result::Result<bool, ClientApiError> {
-        self.validate_error()?;
-        Ok(match self.success_result {
-            Some(SuccessResult::WriteAck(success)) => success,
-            _ => false,
-        })
-    }
-
-    /// Convert response to read results
-    ///
-    /// # Returns
-    /// Vector of optional key-value pairs wrapped in Result
-    pub fn into_read_results(
-        &self
-    ) -> std::result::Result<Vec<Option<ClientResult>>, ClientApiError> {
-        self.validate_error()?;
-        match &self.success_result {
-            Some(SuccessResult::ReadData(data)) => data
-                .results
-                .clone()
-                .into_iter()
-                .map(|item| {
-                    Ok(Some(ClientResult {
-                        key: item.key,
-                        value: item.value,
-                    }))
-                })
-                .collect(),
-            _ => {
-                error!("Invalid response type for read operation");
-                unreachable!()
-            }
-        }
-    }
-
-    /// Validate error code in response header
-    ///
-    /// # Internal Logic
-    /// Converts numeric error code to enum variant
-    pub(crate) fn validate_error(&self) -> std::result::Result<(), ClientApiError> {
-        match ErrorCode::try_from(self.error).unwrap_or(ErrorCode::Uncategorized) {
-            ErrorCode::Success => Ok(()),
-            e => Err(e.into()),
-        }
-    }
-
-    /// Check if this response indicates the leader's term is outdated
-    pub fn is_term_outdated(&self) -> bool {
-        ErrorCode::try_from(self.error).map(|e| e.is_term_outdated()).unwrap_or(false)
-    }
-
-    /// Check if this response indicates a quorum timeout or failure to receive majority responses
-    pub fn is_quorum_timeout_or_failure(&self) -> bool {
-        ErrorCode::try_from(self.error)
-            .map(|e| e.is_quorum_timeout_or_failure())
-            .unwrap_or(false)
-    }
-
-    /// Check if this response indicates a failure to receive majority responses
-    pub fn is_propose_failure(&self) -> bool {
-        ErrorCode::try_from(self.error).map(|e| e.is_propose_failure()).unwrap_or(false)
-    }
-
-    /// Check if this response indicates a a retry required
-    pub fn is_retry_required(&self) -> bool {
-        ErrorCode::try_from(self.error).map(|e| e.is_retry_required()).unwrap_or(false)
-    }
-}
-
-impl ErrorCode {
-    /// Check if this error indicates the leader's term is outdated
-    pub(crate) fn is_term_outdated(&self) -> bool {
-        matches!(self, ErrorCode::TermOutdated)
-    }
-
-    /// Check if this error indicates a quorum timeout or failure to receive majority responses
-    pub(crate) fn is_quorum_timeout_or_failure(&self) -> bool {
-        matches!(
-            self,
-            ErrorCode::ConnectionTimeout | ErrorCode::ProposeFailed | ErrorCode::ClusterUnavailable
-        )
-    }
-
-    /// Check if this error indicates a failure to receive majority responses
-    pub(crate) fn is_propose_failure(&self) -> bool {
-        matches!(self, ErrorCode::ProposeFailed)
-    }
-
-    /// Check if this error indicates a retry required
-    pub(crate) fn is_retry_required(&self) -> bool {
-        matches!(self, ErrorCode::RetryRequired)
-    }
-}
diff --git a/src/constants.rs b/src/constants.rs
deleted file mode 100644
index 29bd0cea..00000000
--- a/src/constants.rs
+++ /dev/null
@@ -1,2 +0,0 @@
-/// Snapshot dir
-pub(crate) const SNAPSHOT_DIR_PREFIX: &str = "snapshot-";
diff --git a/src/lib.rs b/src/lib.rs
deleted file mode 100644
index 8a74934c..00000000
--- a/src/lib.rs
+++ /dev/null
@@ -1,45 +0,0 @@
-#![doc = include_str!("docs/overview.md")]
-
-// #![warn(missing_docs)]
-
-pub mod client;
-pub mod config;
-pub mod docs;
-pub mod node;
-pub mod proto;
-pub mod storage;
-
-#[doc(hidden)]
-pub use client::*;
-#[doc(hidden)]
-pub use config::*;
-#[doc(hidden)]
-pub use node::*;
-
-mod constants;
-mod core;
-mod errors;
-mod membership;
-mod network;
-mod type_config;
-
-#[doc(hidden)]
-pub use core::*;
-
-pub use errors::*;
-pub(crate) use membership::*;
-pub(crate) use network::*;
-pub use storage::*;
-
-#[doc(hidden)]
-pub mod utils;
-#[doc(hidden)]
-pub use type_config::*;
-#[doc(hidden)]
-pub use utils::*;
-
-//-----------------------------------------------------------
-// Test utils
-#[cfg(test)]
-#[doc(hidden)]
-pub mod test_utils;
diff --git a/src/proto/client_extensions.rs b/src/proto/client_extensions.rs
deleted file mode 100644
index b5934d16..00000000
--- a/src/proto/client_extensions.rs
+++ /dev/null
@@ -1,35 +0,0 @@
-//! Extensions for protobuf-generated client types
-//!
-//! This module provides additional methods for protobuf-generated types
-//! that are not automatically generated by the protobuf compiler.
-
-use crate::proto::client::ClientReadRequest;
-use crate::proto::client::ReadConsistencyPolicy;
-
-impl ClientReadRequest {
-    /// Checks if the consistency_policy field is present in the request
-    ///
-    /// Returns true if the client explicitly specified a consistency policy,
-    /// false if the field is absent (should use server default).
-    pub fn has_consistency_policy(&self) -> bool {
-        self.consistency_policy.is_some()
-    }
-
-    /// Gets the consistency policy value safely
-    ///
-    /// Returns Some(policy) if present, None if field is absent.
-    /// Safer alternative that doesn't panic.
-    pub fn get_consistency_policy(&self) -> Option<ReadConsistencyPolicy> {
-        self.consistency_policy.and_then(|policy_i32| {
-            match policy_i32 {
-                x if x == ReadConsistencyPolicy::LeaseRead as i32 => {
-                    Some(ReadConsistencyPolicy::LeaseRead)
-                }
-                x if x == ReadConsistencyPolicy::LinearizableRead as i32 => {
-                    Some(ReadConsistencyPolicy::LinearizableRead)
-                }
-                _ => None, // Invalid value
-            }
-        })
-    }
-}
diff --git a/src/proto/mod.rs b/src/proto/mod.rs
deleted file mode 100644
index e2875525..00000000
--- a/src/proto/mod.rs
+++ /dev/null
@@ -1,34 +0,0 @@
-//! Protocol Buffer definitions and generated code for RPC services.
-//!
-//! This module contains auto-generated Rust types from Protobuf definitions,
-//! typically created using [`tonic-build`] or `protoc` compiler plugins.
-
-pub mod common {
-    include!("../generated/raft.common.rs");
-}
-
-pub mod error {
-    include!("../generated/raft.error.rs");
-}
-
-pub mod cluster {
-    include!("../generated/raft.cluster.rs");
-}
-
-pub mod replication {
-    include!("../generated/raft.replication.rs");
-}
-
-pub mod election {
-    include!("../generated/raft.election.rs");
-}
-
-pub mod storage {
-    include!("../generated/raft.storage.rs");
-}
-
-pub mod client {
-    include!("../generated/raft.client.rs");
-}
-
-pub mod client_extensions;
diff --git a/src/storage/raft_log.rs b/src/storage/raft_log.rs
deleted file mode 100644
index 26e12387..00000000
--- a/src/storage/raft_log.rs
+++ /dev/null
@@ -1,162 +0,0 @@
-//! Core model in Raft: RaftLog Definition
-
-use std::ops::RangeInclusive;
-
-#[cfg(test)]
-use mockall::automock;
-use tonic::async_trait;
-
-use crate::proto::common::entry_payload::Payload;
-use crate::proto::common::Entry;
-use crate::proto::common::EntryPayload;
-use crate::proto::common::LogId;
-use crate::Result;
-
-// /// Configurable persistence strategy for Raft logs
-// #[derive(Clone, Copy, Debug, Serialize, Deserialize, PartialEq)]
-// pub enum PersistenceStrategy {
-//     /// Persist logs to disk before replicating to followers
-//     /// (Stronger durability, lower throughput)
-//     DiskFirst,
-
-//     /// Replicate logs immediately and persist asynchronously
-//     /// (Higher throughput, optimized for low-latency networks)
-//     MemFirst,
-
-//     /// Persist logs in batches at fixed intervals
-//     /// (Balanced approach for mixed workloads)
-//     Batched(usize, u64), // (batch_size, interval_ms)
-// }
-
-// impl Default for PersistenceStrategy {
-//     fn default() -> Self {
-//         Self::Batched(1000, 10)
-//     }
-// }
-
-#[cfg_attr(test, automock)]
-#[async_trait]
-pub trait RaftLog: Send + Sync + 'static {
-    fn entry(
-        &self,
-        index: u64,
-    ) -> Result<Option<Entry>>;
-
-    fn first_entry_id(&self) -> u64;
-
-    fn last_entry_id(&self) -> u64;
-
-    fn last_log_id(&self) -> Option<LogId>;
-
-    fn last_entry(&self) -> Option<Entry>;
-
-    fn is_empty(&self) -> bool;
-
-    fn entry_term(
-        &self,
-        entry_id: u64,
-    ) -> Option<u64>;
-
-    fn pre_allocate_raft_logs_next_index(&self) -> u64;
-
-    /// Pre-allocates a contiguous range of log indices
-    /// Returns inclusive range [start, end] where (end - start + 1) == count
-    fn pre_allocate_id_range(
-        &self,
-        count: u64,
-    ) -> RangeInclusive<u64>;
-
-    fn last_index_for_term(
-        &self,
-        term: u64,
-    ) -> Option<u64>;
-
-    fn first_index_for_term(
-        &self,
-        term: u64,
-    ) -> Option<u64>;
-
-    fn get_entries_range(
-        &self,
-        range: RangeInclusive<u64>,
-    ) -> Result<Vec<Entry>>;
-
-    async fn filter_out_conflicts_and_append(
-        &self,
-        prev_log_index: u64,
-        prev_log_term: u64,
-        new_entries: Vec<Entry>,
-    ) -> Result<Option<LogId>>;
-
-    async fn append_entries(
-        &self,
-        entries: Vec<Entry>,
-    ) -> Result<()>;
-
-    async fn insert_batch(
-        &self,
-        logs: Vec<Entry>,
-    ) -> Result<()>;
-
-    /// Clear out all the entries in local logs before last_applied
-    /// this function will be invoked only when entries been applied to state
-    /// machine successfully
-    async fn purge_logs_up_to(
-        &self,
-        cutoff_index: LogId,
-    ) -> Result<()>;
-
-    async fn flush(&self) -> Result<()>;
-
-    /// @Write
-    async fn reset(&self) -> Result<()>;
-
-    fn calculate_majority_matched_index(
-        &self,
-        current_term: u64,
-        commit_index: u64,
-        matched_ids: Vec<u64>,
-    ) -> Option<u64>;
-
-    fn load_hard_state(&self) -> Result<Option<crate::HardState>>;
-
-    fn save_hard_state(
-        &self,
-        hard_state: &crate::HardState,
-    ) -> Result<()>;
-}
-
-impl EntryPayload {
-    #[allow(dead_code)]
-    #[inline]
-    pub(crate) fn is_config(&self) -> bool {
-        match self.payload {
-            Some(Payload::Command(_)) => false,
-            Some(Payload::Config(_)) => true,
-            Some(Payload::Noop(_)) => false,
-            None => false,
-        }
-    }
-
-    #[allow(dead_code)]
-    #[inline]
-    pub(crate) fn is_command(&self) -> bool {
-        match self.payload {
-            Some(Payload::Command(_)) => true,
-            Some(Payload::Config(_)) => false,
-            Some(Payload::Noop(_)) => false,
-            None => false,
-        }
-    }
-
-    #[allow(dead_code)]
-    #[inline]
-    pub(crate) fn is_noop(&self) -> bool {
-        match self.payload {
-            Some(Payload::Command(_)) => false,
-            Some(Payload::Config(_)) => false,
-            Some(Payload::Noop(_)) => true,
-            None => false,
-        }
-    }
-}
diff --git a/src/test_utils/integration/mod.rs b/src/test_utils/integration/mod.rs
deleted file mode 100644
index afe594c1..00000000
--- a/src/test_utils/integration/mod.rs
+++ /dev/null
@@ -1,253 +0,0 @@
-//! Integration test module for simulating RaftContext components with actual
-//! underlying operations.
-//!
-//! This module provides real-world implementations of storage, network and
-//! handler components rather than using mocking frameworks. Designed for
-//! testing Raft consensus algorithm internals with the following
-//! characteristics:
-//!
-//! - Uses **real storage backends** (SledRaftLog, SledStateStorage) with test isolation through
-//!   temporary databases
-//! - Implements **actual network transport** (GrpcTransport) for RPC communication
-//! - Contains complete handler implementations (ElectionHandler, ReplicationHandler)
-//! - Maintains real cluster membership state
-//!
-//! The [`TestContext`] struct encapsulates a complete testing environment
-//! containing:
-//! - Storage components (raft log, state machine, snapshots)
-//! - Network transport layer
-//! - Cluster membership configuration
-//! - Core Raft handlers
-//!
-//! The [`setup_raft_context`] function initializes a test environment with:
-//! - Fresh database instances via [`reset_dbs`]
-//! - Default or custom peer configurations
-//! - Real gRPC transport binding
-//! - Complete handler chains
-//!
-//! This differs from unit test mocks in that:
-//! - All I/O operations use actual storage implementations
-//! - Network communication uses real transport layers
-//! - State changes persist across operations
-//! - Full Raft state transitions are exercised
-//!
-//! Typical usage scenarios:
-//! - Integration testing of Raft protocol implementation
-//! - End-to-end simulation of node behavior
-//! - Cluster formation and interaction tests
-//! - Failure scenario testing with real component interactions
-
-mod snapshot;
-use std::path::PathBuf;
-use std::sync::Arc;
-
-#[allow(unused)]
-pub(crate) use snapshot::*;
-use tokio::sync::watch;
-
-use super::generate_insert_commands;
-use crate::alias::MOF;
-use crate::alias::ROF;
-use crate::alias::SMOF;
-use crate::alias::TROF;
-use crate::grpc::grpc_transport::GrpcTransport;
-use crate::proto::cluster::NodeMeta;
-use crate::proto::common::Entry;
-use crate::proto::common::EntryPayload;
-use crate::proto::common::NodeStatus;
-use crate::test_utils::mock_state_machine;
-use crate::test_utils::MockTypeConfig;
-use crate::BufferedRaftLog;
-use crate::DefaultStateMachineHandler;
-use crate::ElectionHandler;
-use crate::FileStateMachine;
-use crate::FileStorageEngine;
-use crate::FlushPolicy;
-use crate::LogSizePolicy;
-use crate::MockStateMachine;
-use crate::PersistenceConfig;
-use crate::PersistenceStrategy;
-use crate::RaftLog;
-use crate::RaftMembership;
-use crate::RaftNodeConfig;
-use crate::RaftRole;
-use crate::RaftTypeConfig;
-use crate::ReplicationHandler;
-use crate::StateMachine;
-use crate::StorageEngine;
-use crate::TypeConfig;
-
-#[allow(dead_code)]
-pub struct TestContext<T>
-where
-    T: TypeConfig,
-{
-    pub id: u32,
-
-    // Storages
-    pub raft_log: Arc<ROF<T>>,
-    pub state_machine: Arc<SMOF<T>>,
-
-    // Network
-    pub transport: Arc<TROF<T>>,
-
-    // Cluster Membership
-    pub membership: Arc<MOF<T>>,
-
-    // Handlers
-    pub election_handler: ElectionHandler<T>,
-    pub replication_handler: ReplicationHandler<T>,
-    pub state_machine_handler: DefaultStateMachineHandler<T>,
-
-    pub node_config: RaftNodeConfig,
-    pub arc_node_config: Arc<RaftNodeConfig>,
-}
-
-// If param `restart` is true, we will not reset dbs
-pub fn setup_raft_components(
-    db_path: &str,
-    peers_meta_option: Option<Vec<NodeMeta>>,
-    restart: bool,
-) -> TestContext<RaftTypeConfig<FileStorageEngine, MockStateMachine>> {
-    println!("Test setup_raft_components ...");
-
-    std::env::remove_var("CONFIG_PATH");
-    std::env::remove_var("RAFT__INITIAL_CLUSTER");
-    //start from fresh
-    let id = 1;
-
-    // let tempdir = tempfile::tempdir().unwrap();
-    let path = PathBuf::from(db_path);
-    let storage_engine = Arc::new(FileStorageEngine::new(path).unwrap());
-    if restart {
-        storage_engine.log_store().reset_sync().unwrap();
-    }
-
-    let (buffered_raft_log, receiver) = BufferedRaftLog::new(
-        id,
-        PersistenceConfig {
-            strategy: PersistenceStrategy::DiskFirst,
-            flush_policy: FlushPolicy::Immediate,
-            max_buffered_entries: 10000,
-            ..Default::default()
-        },
-        storage_engine.clone(),
-    );
-    let buffered_raft_log = buffered_raft_log.start(receiver);
-    let mock_state_machine = mock_state_machine();
-    let last_applied_pair = mock_state_machine.last_applied();
-
-    let grpc_transport = GrpcTransport::new(id);
-
-    let peers_meta = if let Some(meta) = peers_meta_option {
-        meta
-    } else {
-        let follower_role = RaftRole::<MockTypeConfig>::follower_role_i32();
-        vec![
-            NodeMeta {
-                id: 1,
-                address: "127.0.0.1:8080".to_string(),
-                role: follower_role,
-                status: NodeStatus::Active.into(),
-            },
-            NodeMeta {
-                id: 2,
-                address: "127.0.0.1:8081".to_string(),
-                role: follower_role,
-                status: NodeStatus::Active.into(),
-            },
-            NodeMeta {
-                id: 3,
-                address: "127.0.0.1:8082".to_string(),
-                role: follower_role,
-                status: NodeStatus::Active.into(),
-            },
-        ]
-    };
-
-    let (_graceful_tx, _graceful_rx) = watch::channel(());
-
-    // Each unit test db path will be different
-    let mut node_config = RaftNodeConfig::default();
-    node_config.cluster.db_root_dir = PathBuf::from(db_path);
-    node_config.cluster.initial_cluster = peers_meta.clone();
-
-    let snapshot_policy = LogSizePolicy::new(
-        node_config.raft.snapshot.max_log_entries_before_snapshot,
-        node_config.raft.snapshot.snapshot_cool_down_since_last_check,
-    );
-
-    let state_machine = Arc::new(mock_state_machine);
-    let state_machine_handler = DefaultStateMachineHandler::new(
-        id,
-        last_applied_pair.index,
-        node_config.raft.commit_handler.max_entries_per_chunk,
-        state_machine.clone(),
-        node_config.raft.snapshot.clone(),
-        snapshot_policy,
-    );
-
-    let node_config_clone = node_config.clone();
-    let arc_node_config = Arc::new(node_config);
-
-    TestContext::<RaftTypeConfig<FileStorageEngine, MockStateMachine>> {
-        id,
-        raft_log: buffered_raft_log,
-        state_machine,
-        transport: Arc::new(grpc_transport),
-        membership: Arc::new(RaftMembership::new(
-            id,
-            arc_node_config.cluster.initial_cluster.clone(),
-            node_config_clone.clone(),
-        )),
-        election_handler: ElectionHandler::new(id),
-        replication_handler: ReplicationHandler::new(id),
-        node_config: node_config_clone,
-        arc_node_config,
-        state_machine_handler,
-    }
-}
-
-pub(crate) async fn insert_raft_log(
-    raft_log: &Arc<ROF<RaftTypeConfig<FileStorageEngine, FileStateMachine>>>,
-    ids: Vec<u64>,
-    term: u64,
-) {
-    let mut entries = Vec::new();
-    for id in ids {
-        let log = Entry {
-            index: raft_log.pre_allocate_raft_logs_next_index(),
-            term,
-            payload: Some(EntryPayload::command(generate_insert_commands(vec![id]))),
-        };
-        entries.push(log);
-    }
-    if let Err(e) = raft_log.insert_batch(entries).await {
-        panic!("error:{e:?}");
-    }
-}
-
-pub(crate) async fn insert_state_machine(
-    state_machine: &SMOF<RaftTypeConfig<FileStorageEngine, FileStateMachine>>,
-    ids: Vec<u64>,
-    term: u64,
-) {
-    let mut entries = Vec::new();
-    for id in ids {
-        let log = Entry {
-            index: id,
-            term,
-            payload: Some(EntryPayload::command(generate_insert_commands(vec![id]))),
-        };
-        entries.push(log);
-    }
-    if let Err(e) = state_machine.apply_chunk(entries).await {
-        panic!("error: {e:?}");
-    }
-}
-
-pub(crate) fn node_config(db_path: &str) -> RaftNodeConfig {
-    let mut s = RaftNodeConfig::new().expect("RaftNodeConfig should be inited successfully.");
-    s.cluster.db_root_dir = PathBuf::from(db_path);
-    s
-}
diff --git a/src/test_utils/mod.rs b/src/test_utils/mod.rs
deleted file mode 100644
index b6a12c35..00000000
--- a/src/test_utils/mod.rs
+++ /dev/null
@@ -1,13 +0,0 @@
-//! the test_utils folder here will share utils or test components betwee unit
-//! tests and integrations tests
-mod common;
-mod entry_builder;
-mod integration;
-mod mock;
-pub mod mock_type_config;
-
-pub use common::*;
-pub use entry_builder::*;
-pub use integration::*;
-pub use mock::*;
-pub use mock_type_config::*;
diff --git a/src/utils/mod.rs b/src/utils/mod.rs
deleted file mode 100644
index 0fb4eac2..00000000
--- a/src/utils/mod.rs
+++ /dev/null
@@ -1,44 +0,0 @@
-#[allow(dead_code)]
-pub mod async_task;
-
-#[allow(dead_code)]
-pub mod cluster;
-
-#[allow(dead_code)]
-pub mod convert;
-
-#[allow(dead_code)]
-pub mod file_io;
-
-#[allow(dead_code)]
-pub mod net;
-
-#[allow(dead_code)]
-pub mod time;
-
-#[allow(dead_code)]
-pub mod scoped_timer;
-
-#[allow(dead_code)]
-pub mod stream;
-
-#[cfg(test)]
-mod utils_test;
-
-#[cfg(test)]
-mod file_io_test;
-
-#[cfg(test)]
-mod async_task_test;
-
-#[cfg(test)]
-mod convert_test;
-
-#[cfg(test)]
-mod net_test;
-
-#[cfg(test)]
-mod stream_test;
-
-#[cfg(test)]
-mod time_test;