diff --git a/CHANGELOG.md b/CHANGELOG.md
index 33309dc..ea5dafc 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,21 @@
 
 All notable changes to this project will be documented in this file.
 
+## [1.2.1] - 2026-04-24
+
+### 🚀 Features
+- **Built-in FastAPI Response**: Added `BFastResponse` directly to the `b_fast` package for easier integration.
+- **Improved Type Support**: Better handling of `BFastError` and updated `BFastResponse` to use built-in encoder.
+
+### 🔧 Fixes
+- **Module Visibility**: Fixed `ModuleNotFoundError`/`ImportError` when using the library in external projects by correctly exporting `BFast` in `__init__.py`.
+- **Typings Organization**: Moved and renamed `.pyi` file to `python/b_fast/_b_fast.pyi` to ensure correct recognition by IDEs and type checkers after installation.
+- **FastAPI Dependency**: Updated `README` to recommend installation with `[fastapi]` extra for projects using FastAPI.
+
+### 📚 Documentation
+- Updated `README` with simplified FastAPI usage example.
+- Fixed installation instructions for better clarity.
+
 ## [1.1.0] - 2026-02-07
 
 ### 🚀 Features
diff --git a/Cargo.toml b/Cargo.toml
index d8a3f05..ca390e2 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "b_fast"
-version = "1.2.0"
+version = "1.2.1"
 edition = "2021"
 
 [lib]
diff --git a/README.md b/README.md
index ae2fee6..245b43d 100644
--- a/README.md
+++ b/README.md
@@ -64,11 +64,17 @@ Complete test including network transfer and deserialization (10,000 objects):
 
 ### Backend (Python)
 ```bash
-uv add bfast-py
+# Basic installation
+pip install bfast-py
+
+# With FastAPI support
+pip install "bfast-py[fastapi]"
 ```
-or
+or with `uv`:
 ```bash
-pip install bfast-py
+uv add bfast-py
+# or
+uv add "bfast-py[fastapi]"
 ```
 
 ### Frontend (TypeScript)
@@ -81,22 +87,12 @@ npm install bfast-client
 ### Backend (Python)
 
 #### 1. FastAPI (Direct Integration) ⭐ Recommended
-B-FAST integrates seamlessly as a response class.
+B-FAST includes a built-in `BFastResponse` for seamless integration.
 
 ```python
-from fastapi import FastAPI, Response
+from fastapi import FastAPI
 from pydantic import BaseModel
-import b_fast
-
-class BFastResponse(Response):
-    media_type = "application/x-bfast"
-    
-    def __init__(self, content=None, *args, **kwargs):
-        super().__init__(content, *args, **kwargs)
-        self.encoder = b_fast.BFast()
-
-    def render(self, content) -> bytes:
-        return self.encoder.encode_packed(content, compress=True)
+from b_fast import BFastResponse
 
 app = FastAPI()
 
@@ -106,6 +102,7 @@ class User(BaseModel):
 
 @app.get("/users", response_class=BFastResponse)
 async def get_users():
+    # Returns binary B-FAST data with automatic LZ4 compression
     return [User(id=i, name=f"User {i}") for i in range(1000)]
 ```
 
diff --git a/client-ts/package-lock.json b/client-ts/package-lock.json
index 5056f37..7c219ac 100644
--- a/client-ts/package-lock.json
+++ b/client-ts/package-lock.json
@@ -1,17 +1,32 @@
 {
-  "name": "@b-fast/client",
-  "version": "1.0.0",
+  "name": "bfast-client",
+  "version": "1.1.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
-      "name": "@b-fast/client",
-      "version": "1.0.0",
+      "name": "bfast-client",
+      "version": "1.1.0",
+      "license": "MIT",
       "dependencies": {
         "lz4js": "^0.2.0"
       },
       "devDependencies": {
+        "@types/node": "^25.6.0",
         "typescript": "^5.0.0"
+      },
+      "engines": {
+        "node": ">=14.0.0"
+      }
+    },
+    "node_modules/@types/node": {
+      "version": "25.6.0",
+      "resolved": "https://registry.npmjs.org/@types/node/-/node-25.6.0.tgz",
+      "integrity": "sha512-+qIYRKdNYJwY3vRCZMdJbPLJAtGjQBudzZzdzwQYkEPQd+PJGixUL5QfvCLDaULoLv+RhT3LDkwEfKaAkgSmNQ==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "undici-types": "~7.19.0"
       }
     },
     "node_modules/lz4js": {
@@ -33,6 +48,13 @@
       "engines": {
         "node": ">=14.17"
       }
+    },
+    "node_modules/undici-types": {
+      "version": "7.19.2",
+      "resolved": "https://registry.npmjs.org/undici-types/-/undici-types-7.19.2.tgz",
+      "integrity": "sha512-qYVnV5OEm2AW8cJMCpdV20CDyaN3g0AjDlOGf1OW4iaDEx8MwdtChUp4zu4H0VP3nDRF/8RKWH+IPp9uW0YGZg==",
+      "dev": true,
+      "license": "MIT"
     }
   }
 }
diff --git a/client-ts/package.json b/client-ts/package.json
index 908b3a4..7f52ab4 100644
--- a/client-ts/package.json
+++ b/client-ts/package.json
@@ -32,9 +32,10 @@
     "lz4js": "^0.2.0"
   },
   "devDependencies": {
+    "@types/node": "^25.6.0",
     "typescript": "^5.0.0"
   },
   "engines": {
     "node": ">=14.0.0"
   }
-}
\ No newline at end of file
+}
diff --git a/pyproject.toml b/pyproject.toml
index 534b367..a9262ab 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "maturin"
 
 [project]
 name = "bfast-py"
-version = "1.2.0"
+version = "1.2.1"
 description = "⚡ B-FAST (Binary Fast Adaptive Serialization Transfer) - Protocolo de serialização binária de ultra-alta performance, desenvolvido em Rust para o ecossistema Python e TypeScript"
 readme = "README.md"
 requires-python = ">=3.8"
diff --git a/python/b_fast/__init__.py b/python/b_fast/__init__.py
index a61c2bc..f368754 100644
--- a/python/b_fast/__init__.py
+++ b/python/b_fast/__init__.py
@@ -4,8 +4,8 @@
 Ultra-fast binary serialization library with Rust backend.
 """
 
-from ._b_fast import BFast
+from ._b_fast import BFast, BFastError
 from .integration import BFastResponse
 
-__version__ = "1.2.0"
-__all__ = ["BFast", "BFastResponse"]
+__version__ = "1.2.1"
+__all__ = ["BFast", "BFastError", "BFastResponse"]
diff --git a/python/b_fast.pyi b/python/b_fast/_b_fast.pyi
similarity index 100%
rename from python/b_fast.pyi
rename to python/b_fast/_b_fast.pyi
diff --git a/python/b_fast/integration.py b/python/b_fast/integration.py
index 946fe24..4093298 100644
--- a/python/b_fast/integration.py
+++ b/python/b_fast/integration.py
@@ -19,14 +19,14 @@ class BFastResponse(Response):
     def __init__(self, content: Any, **kwargs):
         if not FASTAPI_AVAILABLE:
             raise ImportError(
-                "FastAPI is required to use BFastResponse. Install it with 'pip install fastapi'."
+                "FastAPI is required to use BFastResponse. Install it with 'pip install bfast-py[fastapi]'."
             )
 
         # Delayed import to avoid circular dependency
         from ._b_fast import BFast
 
-        super().__init__(content=content, **kwargs)
         self.encoder = BFast()
+        super().__init__(content=content, **kwargs)
 
     def render(self, content: Any) -> bytes:
         return self.encoder.encode_packed(content, compress=True)