diff --git a/.github/workflows/package-apisix-runtime-deb-openresty-1.21.yml b/.github/workflows/package-apisix-runtime-deb-openresty-1.21.yml
index 99e08b017..98604f85d 100644
--- a/.github/workflows/package-apisix-runtime-deb-openresty-1.21.yml
+++ b/.github/workflows/package-apisix-runtime-deb-openresty-1.21.yml
@@ -35,6 +35,8 @@ jobs:
           sudo apt-get install -y make ruby ruby-dev rubygems build-essential
 
       - name: Build apisix-runtime deb
+        env:
+          NGX_HTTP_FFI_CLIENT_TOKEN: ${{ secrets.NGX_HTTP_FFI_CLIENT_TOKEN }}
         run: |
           if [ "${{ matrix.platform.arch }}" == "arm64" ]; then
             make package type=deb app=apisix-runtime runtime_version=${BUILD_APISIX_RUNTIME_VERSION} image_base=debian image_tag=bullseye-slim arch=linux/arm64/v8
diff --git a/.github/workflows/package-apisix-runtime-deb-ubuntu20.04.yml b/.github/workflows/package-apisix-runtime-deb-ubuntu20.04.yml
index f1153eaca..d9b711396 100644
--- a/.github/workflows/package-apisix-runtime-deb-ubuntu20.04.yml
+++ b/.github/workflows/package-apisix-runtime-deb-ubuntu20.04.yml
@@ -28,6 +28,8 @@ jobs:
           sudo apt-get install -y make ruby ruby-dev rubygems build-essential
 
       - name: build apisix-runtime deb
+        env:
+          NGX_HTTP_FFI_CLIENT_TOKEN: ${{ secrets.NGX_HTTP_FFI_CLIENT_TOKEN }}
         run: |
           make package type=deb app=apisix-runtime runtime_version=${BUILD_APISIX_RUNTIME_VERSION} image_base=ubuntu image_tag=24.04
 
diff --git a/.github/workflows/package-apisix-runtime-rpm-el.yml b/.github/workflows/package-apisix-runtime-rpm-el.yml
index d92703683..6f1f80295 100644
--- a/.github/workflows/package-apisix-runtime-rpm-el.yml
+++ b/.github/workflows/package-apisix-runtime-rpm-el.yml
@@ -56,6 +56,7 @@ jobs:
         env:
           # Stream inner docker build output so a failing build step surfaces in CI.
           BUILDKIT_PROGRESS: plain
+          NGX_HTTP_FFI_CLIENT_TOKEN: ${{ secrets.NGX_HTTP_FFI_CLIENT_TOKEN }}
         run: |
           make package type=rpm app=apisix-runtime runtime_version=${BUILD_APISIX_RUNTIME_VERSION} \
             image_base=rockylinux image_tag=${{ matrix.dist.image_tag }} arch=linux/amd64
diff --git a/.github/workflows/package-apisix-runtime-rpm-ubi.yml b/.github/workflows/package-apisix-runtime-rpm-ubi.yml
index e2ecb459f..adf9084b3 100644
--- a/.github/workflows/package-apisix-runtime-rpm-ubi.yml
+++ b/.github/workflows/package-apisix-runtime-rpm-ubi.yml
@@ -26,6 +26,8 @@ jobs:
           sudo apt-get install -y make ruby ruby-dev rubygems build-essential
 
       - name: build apisix-runtime rpm
+        env:
+          NGX_HTTP_FFI_CLIENT_TOKEN: ${{ secrets.NGX_HTTP_FFI_CLIENT_TOKEN }}
         run: |
           make package type=rpm app=apisix-runtime runtime_version=${BUILD_APISIX_RUNTIME_VERSION} image_base=registry.access.redhat.com/ubi9/ubi image_tag=9.6
 
diff --git a/.github/workflows/release-apisix-runtime.yml b/.github/workflows/release-apisix-runtime.yml
index 7ba6f960b..06d18510a 100644
--- a/.github/workflows/release-apisix-runtime.yml
+++ b/.github/workflows/release-apisix-runtime.yml
@@ -52,11 +52,27 @@ jobs:
           sudo apt-get update
           sudo apt-get install -y make ruby ruby-dev rubygems build-essential
 
+      # A released runtime must carry ngx_http_ffi_client. The build itself is
+      # lenient so fork PRs, which get no secrets, still pass; here the secret
+      # has to be there, or the release would silently ship without the module.
+      - name: Require the ngx_http_ffi_client token
+        env:
+          NGX_HTTP_FFI_CLIENT_TOKEN: ${{ secrets.NGX_HTTP_FFI_CLIENT_TOKEN }}
+        run: |
+          if [ -z "${NGX_HTTP_FFI_CLIENT_TOKEN}" ]; then
+            echo "NGX_HTTP_FFI_CLIENT_TOKEN is not set; a release build must carry ngx_http_ffi_client" >&2
+            exit 1
+          fi
+
       - name: Build apisix-runtime deb
+        env:
+          NGX_HTTP_FFI_CLIENT_TOKEN: ${{ secrets.NGX_HTTP_FFI_CLIENT_TOKEN }}
         run: |
           make package type=deb app=apisix-runtime runtime_version="${VERSION}" image_base=debian image_tag=bookworm-slim arch=${{ matrix.platform.build_arch }}
 
       - name: Build apisix-runtime-debug deb
+        env:
+          NGX_HTTP_FFI_CLIENT_TOKEN: ${{ secrets.NGX_HTTP_FFI_CLIENT_TOKEN }}
         run: |
           make package type=deb app=apisix-runtime runtime_version="${VERSION}" image_base=debian image_tag=bookworm-slim arch=${{ matrix.platform.build_arch }} build_latest=latest artifact=apisix-runtime-debug
 
@@ -111,10 +127,23 @@ jobs:
           sudo apt-get update
           sudo apt-get install -y make ruby ruby-dev rubygems build-essential rpm
 
+      # A released runtime must carry ngx_http_ffi_client. The build itself is
+      # lenient so fork PRs, which get no secrets, still pass; here the secret
+      # has to be there, or the release would silently ship without the module.
+      - name: Require the ngx_http_ffi_client token
+        env:
+          NGX_HTTP_FFI_CLIENT_TOKEN: ${{ secrets.NGX_HTTP_FFI_CLIENT_TOKEN }}
+        run: |
+          if [ -z "${NGX_HTTP_FFI_CLIENT_TOKEN}" ]; then
+            echo "NGX_HTTP_FFI_CLIENT_TOKEN is not set; a release build must carry ngx_http_ffi_client" >&2
+            exit 1
+          fi
+
       - name: Build apisix-runtime rpm (${{ matrix.dist.el }} ${{ matrix.platform.rpm_arch }})
         env:
           # Stream inner docker build output so a failing build step surfaces in CI.
           BUILDKIT_PROGRESS: plain
+          NGX_HTTP_FFI_CLIENT_TOKEN: ${{ secrets.NGX_HTTP_FFI_CLIENT_TOKEN }}
         run: |
           make package type=rpm app=apisix-runtime runtime_version="${VERSION}" \
             image_base=rockylinux image_tag=${{ matrix.dist.image_tag }} \
diff --git a/Makefile b/Makefile
index dc67e5f8a..b516567ac 100644
--- a/Makefile
+++ b/Makefile
@@ -39,6 +39,16 @@ endif
 # Set arch to linux/amd64 if it's not defined
 arch ?= linux/amd64
 
+# api7/ngx_http_ffi_client is private, so the runtime build reads a token from
+# a BuildKit secret rather than a build arg, which would land in image history.
+# Without the token the runtime is built without that module.
+NGX_HTTP_FFI_CLIENT_TOKEN ?=
+ifneq ($(NGX_HTTP_FFI_CLIENT_TOKEN),)
+ffi_client_secret=--secret id=ngx_http_ffi_client_token,env=NGX_HTTP_FFI_CLIENT_TOKEN
+else
+ffi_client_secret=
+endif
+
 # Detect the CPU architecture
 CPU_ARCH := $(shell uname -m)
 # Map the architecture to Docker platform
@@ -94,7 +104,7 @@ endif
 ### $(4) is code path
 ifneq ($(buildx), True)
 define build_runtime
-	docker build -t apache/$(1)-$(3):$(runtime_version) \
+	DOCKER_BUILDKIT=1 docker build -t apache/$(1)-$(3):$(runtime_version) \
 		--build-arg checkout_v=$(checkout) \
 		--build-arg VERSION=$(version) \
 		--build-arg RUNTIME_VERSION=$(runtime_version) \
@@ -102,6 +112,7 @@ define build_runtime
 		--build-arg IMAGE_TAG=$(image_tag) \
 		--build-arg BUILD_LATEST=$(build_latest) \
 		--build-arg CODE_PATH=$(4) \
+		$(ffi_client_secret) \
     --platform $(arch) \
 		-f ./dockerfiles/Dockerfile.$(2).$(3) .
 endef
@@ -115,6 +126,7 @@ define build_runtime
 		--build-arg IMAGE_TAG=$(image_tag) \
 		--build-arg BUILD_LATEST=$(build_latest) \
 		--build-arg CODE_PATH=$(4) \
+		$(ffi_client_secret) \
 		--load \
 		--cache-from=$(cache_from) \
 		--cache-to=$(cache_to) \
diff --git a/README.md b/README.md
index 8bb6fab99..0c7778970 100644
--- a/README.md
+++ b/README.md
@@ -18,6 +18,7 @@
 | image_base      | False    | the environment for packaging, if type is `rpm` the default image_base is `centos`, if type is `deb` the default image_base is `ubuntu`                                           | image_base=centos                    |
 | image_tag       | False    | the environment for packaging, it's value can be `16.04\|18.04\|20.04\|6\|7\|8`, if type is `rpm` the default image_tag is `7`, if type is `deb` the default image_tag is `20.04` | image_tag=7                          |
 | buildx          | False    | if `True`, use buildx to build docker images, which may speed up GitHub Actions                                                                                                   | buildx=True                          |
+| NGX_HTTP_FFI_CLIENT_TOKEN | False | environment variable holding a token that can read `api7/ngx_http_ffi_client`. It is passed to the runtime build as a BuildKit secret and never as a build arg. Without it the runtime is built without that module | NGX_HTTP_FFI_CLIENT_TOKEN=ghp_xxx make package ... |
 
 ## Example
 
@@ -106,6 +107,23 @@ ls output/
 apisix-runtime_1.0.0-0~ubuntu20.04_amd64.deb
 ```
 
+### ngx_http_ffi_client
+
+`ngx_http_ffi_client` is the C HTTP client the AI plugins use for outbound LLM
+requests. `api7/ngx_http_ffi_client` is a private repository, so the runtime
+build fetches it only when `NGX_HTTP_FFI_CLIENT_TOKEN` is set, and otherwise
+prints a warning and builds the runtime without it. `ai-proxy` falls back to
+`lua-resty-http` on a runtime that does not carry the module, so both runtimes
+work; only the outbound CPU cost differs.
+
+```sh
+NGX_HTTP_FFI_CLIENT_TOKEN=<token> \
+  make package type=deb app=apisix-runtime version=1.0.0
+```
+
+The commit is pinned by `ngx_http_ffi_client_ver` in `build-apisix-runtime.sh`,
+since the repository carries no tags yet.
+
 ## Details
 
 - `Makefile` the entrance of the packager
diff --git a/build-apisix-runtime.sh b/build-apisix-runtime.sh
index fa231d529..1eac48c1b 100755
--- a/build-apisix-runtime.sh
+++ b/build-apisix-runtime.sh
@@ -36,6 +36,24 @@ fi
 wasm_nginx_module_ver="0.7.0"
 lua_var_nginx_module_ver="v0.5.3"
 lua_resty_events_ver="0.2.0"
+# api7/ngx_http_ffi_client is still a private repository and carries no tags,
+# so it is pinned by commit and fetched with a token. A build without the token
+# leaves the module out and is otherwise unchanged.
+ngx_http_ffi_client_ver=${ngx_http_ffi_client_ver:-"f13fcfa4e923ad82844bf49d9d3b3d283371ef66"}
+if [[ ! "$ngx_http_ffi_client_ver" =~ ^[A-Za-z0-9._/-]+$ ]]; then
+    echo "ERROR: invalid ngx_http_ffi_client_ver: $ngx_http_ffi_client_ver" >&2
+    exit 1
+fi
+# the trace stays off around the token, and only the derived yes/no reaches it
+set +x
+NGX_HTTP_FFI_CLIENT_TOKEN=${NGX_HTTP_FFI_CLIENT_TOKEN:-}
+if [ -n "$NGX_HTTP_FFI_CLIENT_TOKEN" ]; then
+    ngx_http_ffi_client_have_token="yes"
+else
+    ngx_http_ffi_client_have_token="no"
+fi
+set -x
+ngx_http_ffi_client_dir="ngx_http_ffi_client-${ngx_http_ffi_client_ver}"
 
 
 install_openssl_3(){
@@ -134,6 +152,33 @@ else
         lua-var-nginx-module-${lua_var_nginx_module_ver}
 fi
 
+if [ "$repo" == ngx_http_ffi_client ]; then
+    cp -r "$prev_workdir" "./$ngx_http_ffi_client_dir"
+elif [ "$ngx_http_ffi_client_have_token" == "yes" ]; then
+    # A private repository pinned by commit, so fetch rather than clone -b.
+    # The token stays off the trace and out of the repository's git config.
+    mkdir "$ngx_http_ffi_client_dir"
+    (
+        set +x
+        cd "$ngx_http_ffi_client_dir" || exit 1
+        git init -q
+        git -c "http.extraheader=Authorization: Basic $(printf 'x-access-token:%s' \
+                "$NGX_HTTP_FFI_CLIENT_TOKEN" | base64 | tr -d '\n')" \
+            fetch -q --depth=1 \
+            https://github.com/api7/ngx_http_ffi_client.git "$ngx_http_ffi_client_ver"
+        git checkout -q FETCH_HEAD
+    )
+else
+    echo "WARNING: NGX_HTTP_FFI_CLIENT_TOKEN is not set, building apisix-runtime" \
+         "without ngx_http_ffi_client. ai-proxy falls back to lua-resty-http" \
+         "on such a runtime." >&2
+fi
+
+ngx_http_ffi_client_configure_arg=""
+if [ -d "$ngx_http_ffi_client_dir" ]; then
+    ngx_http_ffi_client_configure_arg="--add-module=../$ngx_http_ffi_client_dir"
+fi
+
 cd ngx_multi_upstream_module-${ngx_multi_upstream_module_ver} || exit 1
 ./patch.sh ../openresty-${OPENRESTY_VERSION}
 cd ..
@@ -165,6 +210,11 @@ else
 fi
 
 
+# ngx_http_ffi_client compiles against lua-nginx-module's public API, which it
+# reaches through the bundled copy rather than a separate checkout.
+ngx_lua_bundle_dir=$(find bundle -maxdepth 1 -type d -name 'ngx_lua-*' | head -n 1)
+export NGX_HTTP_LUA_MODULE_DIR="$PWD/$ngx_lua_bundle_dir"
+
 ./configure --prefix="$OR_PREFIX" \
     --with-cc-opt="-DAPISIX_RUNTIME_VER=$runtime_version $cc_opt" \
     --with-ld-opt="-Wl,-rpath,$OR_PREFIX/wasmtime-c-api/lib $ld_opt" \
@@ -177,6 +227,7 @@ fi
     --add-module=../wasm-nginx-module-${wasm_nginx_module_ver} \
     --add-module=../lua-var-nginx-module-${lua_var_nginx_module_ver} \
     --add-module=../lua-resty-events-${lua_resty_events_ver} \
+    $ngx_http_ffi_client_configure_arg \
     --with-poll_module \
     --with-pcre-jit \
     --without-http_rds_json_module \
@@ -220,6 +271,13 @@ sudo install -d "$OR_PREFIX"/lualib/resty/events/compat/
 sudo install -m 644 lualib/resty/events/compat/*.lua "$OR_PREFIX"/lualib/resty/events/compat/
 cd ..
 
+if [ -d "$ngx_http_ffi_client_dir" ]; then
+    # the C module needs its FFI bindings on the runtime's lua_package_path
+    sudo install -d "$OR_PREFIX"/lualib/resty/
+    sudo install -m 644 "$ngx_http_ffi_client_dir"/lib/resty/ngx_http_ffi_client.lua \
+        "$OR_PREFIX"/lualib/resty/
+fi
+
 cd "apisix-nginx-module-${apisix_nginx_module_ver}" || exit 1
 sudo OPENRESTY_PREFIX="$OR_PREFIX" make install
 cd ..
diff --git a/dockerfiles/Dockerfile.apisix-runtime.deb b/dockerfiles/Dockerfile.apisix-runtime.deb
index cda3dfe89..d24f7a955 100644
--- a/dockerfiles/Dockerfile.apisix-runtime.deb
+++ b/dockerfiles/Dockerfile.apisix-runtime.deb
@@ -1,3 +1,4 @@
+# syntax=docker/dockerfile:1
 ARG IMAGE_BASE="debian"
 ARG IMAGE_TAG="bullseye-slim"
 
@@ -20,7 +21,11 @@ ENV build_latest=${BUILD_LATEST:-}
 
 COPY ${CODE_PATH} ./
 
-RUN mv ./utils/build-common.sh ./utils/determine-dist.sh ./ \
+# the secret is optional: without it the runtime is built without
+# ngx_http_ffi_client
+RUN --mount=type=secret,id=ngx_http_ffi_client_token \
+    export NGX_HTTP_FFI_CLIENT_TOKEN="$(cat /run/secrets/ngx_http_ffi_client_token 2>/dev/null || true)" \
+    && mv ./utils/build-common.sh ./utils/determine-dist.sh ./ \
     && ./build-common.sh build_apisix_runtime_deb  ${build_latest} \
     # determine dist and write it into /tmp/dist file
     && ./determine-dist.sh
diff --git a/dockerfiles/Dockerfile.apisix-runtime.rpm b/dockerfiles/Dockerfile.apisix-runtime.rpm
index 82e3b07ca..78dbc03ff 100644
--- a/dockerfiles/Dockerfile.apisix-runtime.rpm
+++ b/dockerfiles/Dockerfile.apisix-runtime.rpm
@@ -1,3 +1,4 @@
+# syntax=docker/dockerfile:1
 ARG IMAGE_BASE="registry.access.redhat.com/ubi9/ubi"
 ARG IMAGE_TAG="9.6"
 
@@ -18,7 +19,11 @@ ENV runtime_version=${RUNTIME_VERSION}
 
 COPY ${CODE_PATH} ./
 
-RUN curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y \
+# the secret is optional: without it the runtime is built without
+# ngx_http_ffi_client
+RUN --mount=type=secret,id=ngx_http_ffi_client_token \
+    export NGX_HTTP_FFI_CLIENT_TOKEN="$(cat /run/secrets/ngx_http_ffi_client_token 2>/dev/null || true)" \
+    && curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y \
     && source "$HOME/.cargo/env" \
     && rustup install 1.69 \
     && rustup default 1.69 \