diff --git a/CHANGELOG.md b/CHANGELOG.md
index e08180e..5708868 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,31 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ---
 
 ## [Unreleased]
+## v1.20.1 — Improved CLI Error UX & Build Feedback
+
+### ✨ CLI — Error reporting & diagnostics
+- Introduce **Python-like compiler error rendering** with code frames
+  `(file:line:column + surrounding context)`
+- Highlight **only the faulty line** with a red caret (`^`) for instant readability
+- Safely truncate very long lines with **UTF-8–aware ellipsis**
+- Add **precise, Vix-style hints** for common mistakes
+  (e.g. `Response::json()` misuse)
+- Hide verbose alternative diagnostics unless log level is `debug` or `trace`
+- Improve `run` / script error reporting for clearer, actionable diagnostics
+
+### 🔨 CLI — Build output & Ninja integration
+- Restore **live Ninja progress output** (`[x/y %]`) during builds
+- Filter noisy compiler command output in live mode
+- Keep **full raw build logs** in `build.log` for post-mortem diagnostics
+- Let `ErrorHandler` display **structured, human-readable errors** on failure
+- Introduce **progress-only build output mode**
+- Fix unused variables and header warnings in build pipeline
+
+### 🧩 Internal
+- Minor internal cleanups to support improved error UX
+- No breaking changes
+
+
 ## v1.20.0 — Modules, Registry & Dependency Workflow (Latest)
 
 ### ✨ Nouveautés majeures
diff --git a/examples/hello_routes.cpp b/examples/hello_routes.cpp
index 35a20f2..c2740ec 100644
--- a/examples/hello_routes.cpp
+++ b/examples/hello_routes.cpp
@@ -37,7 +37,7 @@ int main()
 
   // Example with path param
   app.get("/users/{id}", [](Request &, Response &res)
-          { res.status(4040).json({"error", "User not found"}); });
+          { res.status(404).json({"error", "User not found"}); });
 
   app.get("/hello", [](const Request &, Response &res)
           {
diff --git a/examples/http/router_params.cpp b/examples/http/router_params.cpp
index 0633c32..2e55104 100644
--- a/examples/http/router_params.cpp
+++ b/examples/http/router_params.cpp
@@ -38,20 +38,20 @@ int main()
   // Example:
   //   GET /posts/2025/hello-world
   //
-  app.get("/posts", [](Request &req, Response &res)
+  app.get("/posts/{year}/{slug}", [](Request &req, Response &res)
           {
-        const auto year = req.query_value("year");
-        const auto slug = req.query_value("slug");
-
-        res.json(json::kv({
-            {"year",       year},
-            {"slug",       slug},
-            {"title",      "Post: " + slug},
-            {"message",    "This is an example route with multiple params."},
-            {"powered_by", "Vix.cpp"},
-            {"params", req.params()},
-            {"query", req.query()}
-        })); });
+  const auto year = req.param("year");
+  const auto slug = req.param("slug");
+
+  res.json(json::kv({
+      {"year", year},
+      {"slug", slug},
+      {"title", "Post: " + slug},
+      {"message", "This is an example route with multiple params."},
+      {"powered_by", "Vix.cpp"},
+      {"params", req.params()},
+      {"query", req.query()}
+  })); });
 
   // Optional: a root route for discoverability
   app.get("/", [](Request &, Response &res)
@@ -59,5 +59,4 @@ int main()
                       "hint", "Try GET /hello/Alice or /posts/2025/hello-world"}); });
 
   app.run(8080);
-  return 0;
 }
diff --git a/modules/cli b/modules/cli
index 8356c52..88b72fe 160000
--- a/modules/cli
+++ b/modules/cli
@@ -1 +1 @@
-Subproject commit 8356c52c79a14ebd490b9f75be227c18213c6dc2
+Subproject commit 88b72fe6d1c50ea9e6ab36856c8d02c8b403cc88
diff --git a/modules/core b/modules/core
index cb37164..1740475 160000
--- a/modules/core
+++ b/modules/core
@@ -1 +1 @@
-Subproject commit cb37164d311259f61e25c5edd16fadbfe826c8cb
+Subproject commit 17404752674c8006acd0a2d509051b9115108331
diff --git a/modules/utils b/modules/utils
index d123f0e..69a2cb4 160000
--- a/modules/utils
+++ b/modules/utils
@@ -1 +1 @@
-Subproject commit d123f0ed9f73c3434d67438967979db440c28283
+Subproject commit 69a2cb4efab39781f6f4ed4de5ee9cdc498dd49b