Add LLM-friendly API documentation

This commit adds a comprehensive LLM.md file containing: - Complete API reference for FastAPI classes and methods - Usage examples with proper code snippets - Parameter descriptions and return types - Structured documentation optimized for LLM consumption The documentation covers all major FastAPI components including: - Core FastAPI application class - Request/Response handling - Dependency injection system - Security and authentication - Background tasks and middleware - WebSocket support - Testing utilities
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+# FastAPI Library API Documentation
+
+FastAPI is a modern, fast (high-performance), web framework for building APIs with Python 3.7+ based on standard Python type hints.
+
+## Installation
+```bash
+pip install fastapi
+pip install "uvicorn[standard]"  # ASGI server
+```
+
+## Core Application
+
+### FastAPI Class
+```python
+from fastapi import FastAPI
+
+class FastAPI(Starlette):
+    """FastAPI app class, the main entrypoint to use FastAPI."""
+```
+
+### Constructor Parameters
+```python
+app = FastAPI(
+    debug: bool = False,
+    routes: Optional[List[BaseRoute]] = None,
+    title: str = "FastAPI",
+    summary: Optional[str] = None,
+    description: str = "",
+    version: str = "0.1.0",
+    openapi_url: Optional[str] = "/openapi.json",
+    openapi_tags: Optional[List[Dict[str, Any]]] = None,
+    servers: Optional[List[Dict[str, Union[str, Any]]]] = None,
+    dependencies: Optional[Sequence[Depends]] = None,
+    default_response_class: Type[Response] = JSONResponse,
+    redirect_slashes: bool = True,
+    docs_url: Optional[str] = "/docs",
+    redoc_url: Optional[str] = "/redoc",
+    swagger_ui_oauth2_redirect_url: Optional[str] = "/docs/oauth2-redirect",
+    swagger_ui_init_oauth: Optional[Dict[str, Any]] = None,
+    middleware: Optional[Sequence[Middleware]] = None,
+    exception_handlers: Optional[Dict[Union[int, Type[Exception]], Callable]] = None,
+    on_startup: Optional[Sequence[Callable]] = None,
+    on_shutdown: Optional[Sequence[Callable]] = None,
+    lifespan: Optional[Lifespan] = None,
+    terms_of_service: Optional[str] = None,
+    contact: Optional[Dict[str, Union[str, Any]]] = None,
+    license_info: Optional[Dict[str, Union[str, Any]]] = None,
+    openapi_prefix: str = "",
+    root_path: str = "",
+    root_path_in_servers: bool = True,
+    responses: Optional[Dict[Union[int, str], Dict[str, Any]]] = None,
+    callbacks: Optional[List[BaseRoute]] = None,
+    webhooks: Optional[APIRouter] = None,
+    deprecated: Optional[bool] = None,
+    include_in_schema: bool = True,
+    swagger_ui_parameters: Optional[Dict[str, Any]] = None,
+    generate_unique_id_function: Callable[[APIRoute], str] = generate_unique_id,
+    separate_input_output_schemas: bool = True,
+)
+```
+
+### HTTP Method Decorators
+```python
+@app.get(path: str, **kwargs)
+@app.post(path: str, **kwargs)
+@app.put(path: str, **kwargs)
+@app.delete(path: str, **kwargs)
+@app.patch(path: str, **kwargs)
+@app.options(path: str, **kwargs)
+@app.head(path: str, **kwargs)
+@app.trace(path: str, **kwargs)
+```
+
+### Core Methods
+```python
+app.api_route(path: str, methods: List[str], **kwargs)
+app.add_api_route(path: str, endpoint: Callable, **kwargs)
+app.websocket(path: str, **kwargs)
+app.include_router(router: APIRouter, prefix: str = "", **kwargs)
+app.openapi() -> Dict[str, Any]
+```
+
+
+## Routing and Path Operations
+
+### APIRouter
+```python
+from fastapi import APIRouter
+
+router = APIRouter(
+    prefix: str = "",
+    tags: Optional[List[Union[str, Enum]]] = None,
+    dependencies: Optional[Sequence[Depends]] = None,
+    default_response_class: Type[Response] = JSONResponse,
+    responses: Optional[Dict[Union[int, str], Dict[str, Any]]] = None,
+    callbacks: Optional[List[BaseRoute]] = None,
+    routes: Optional[List[routing.BaseRoute]] = None,
+    redirect_slashes: bool = True,
+    default: Optional[ASGIApp] = None,
+    dependency_overrides_provider: Optional[Any] = None,
+    route_class: Type[APIRoute] = APIRoute,
+    on_startup: Optional[Sequence[Callable[[], Any]]] = None,
+    on_shutdown: Optional[Sequence[Callable[[], Any]]] = None,
+    lifespan: Optional[Lifespan[Any]] = None,
+    deprecated: Optional[bool] = None,
+    include_in_schema: bool = True,
+    generate_unique_id_function: Callable[[APIRoute], str] = generate_unique_id,
+)
+```
+
+### Router Methods
+```python
+# HTTP method decorators (same as FastAPI app)
+@router.get(path: str, **kwargs)
+@router.post(path: str, **kwargs)
+@router.put(path: str, **kwargs)
+@router.delete(path: str, **kwargs)
+@router.patch(path: str, **kwargs)
+@router.options(path: str, **kwargs)
+@router.head(path: str, **kwargs)
+@router.trace(path: str, **kwargs)
+
+# Core methods
+router.api_route(path: str, methods: List[str], **kwargs)
+router.add_api_route(path: str, endpoint: Callable, **kwargs)
+router.websocket(path: str, **kwargs)
+router.include_router(router: APIRouter, **kwargs)
+```
+
+## Parameter Functions
+
+### Path Parameters
+```python
+from fastapi import Path
+
+def Path(
+    default: Any = ...,
+    *,
+    alias: Optional[str] = None,
+    title: Optional[str] = None,
+    description: Optional[str] = None,
+    gt: Optional[float] = None,
+    ge: Optional[float] = None,
+    lt: Optional[float] = None,
+    le: Optional[float] = None,
+    min_length: Optional[int] = None,
+    max_length: Optional[int] = None,
+    regex: Optional[str] = None,
+    example: Any = Undefined,
+    examples: Optional[Dict[str, Any]] = None,
+    deprecated: Optional[bool] = None,
+    include_in_schema: bool = True,
+    **extra: Any,
+) -> Any
+```
+
+### Query Parameters
+```python
+from fastapi import Query
+
+def Query(
+    default: Any = Undefined,
+    *,
+    alias: Optional[str] = None,
+    title: Optional[str] = None,
+    description: Optional[str] = None,
+    gt: Optional[float] = None,
+    ge: Optional[float] = None,
+    lt: Optional[float] = None,
+    le: Optional[float] = None,
+    min_length: Optional[int] = None,
+    max_length: Optional[int] = None,
+    regex: Optional[str] = None,
+    example: Any = Undefined,
+    examples: Optional[Dict[str, Any]] = None,
+    deprecated: Optional[bool] = None,
+    include_in_schema: bool = True,
+    **extra: Any,
+) -> Any
+```
+
+### Request Body
+```python
+from fastapi import Body
+
+def Body(
+    default: Any = Undefined,
+    *,
+    embed: bool = False,
+    media_type: str = "application/json",
+    alias: Optional[str] = None,
+    title: Optional[str] = None,
+    description: Optional[str] = None,
+    gt: Optional[float] = None,
+    ge: Optional[float] = None,
+    lt: Optional[float] = None,
+    le: Optional[float] = None,
+    min_length: Optional[int] = None,
+    max_length: Optional[int] = None,
+    regex: Optional[str] = None,
+    example: Any = Undefined,
+    examples: Optional[Dict[str, Any]] = None,
+    **extra: Any,
+) -> Any
+```
+
+### Headers and Cookies
+```python
+from fastapi import Header, Cookie
+
+def Header(
+    default: Any = Undefined,
+    *,
+    alias: Optional[str] = None,
+    convert_underscores: bool = True,
+    title: Optional[str] = None,
+    description: Optional[str] = None,
+    gt: Optional[float] = None,
+    ge: Optional[float] = None,
+    lt: Optional[float] = None,
+    le: Optional[float] = None,
+    min_length: Optional[int] = None,
+    max_length: Optional[int] = None,
+    regex: Optional[str] = None,
+    example: Any = Undefined,
+    examples: Optional[Dict[str, Any]] = None,
+    deprecated: Optional[bool] = None,
+    include_in_schema: bool = True,
+    **extra: Any,
+) -> Any
+
+def Cookie(
+    default: Any = Undefined,
+    *,
+    alias: Optional[str] = None,
+    title: Optional[str] = None,
+    description: Optional[str] = None,
+    gt: Optional[float] = None,
+    ge: Optional[float] = None,
+    lt: Optional[float] = None,
+    le: Optional[float] = None,
+    min_length: Optional[int] = None,
+    max_length: Optional[int] = None,
+    regex: Optional[str] = None,
+    example: Any = Undefined,
+    examples: Optional[Dict[str, Any]] = None,
+    deprecated: Optional[bool] = None,
+    include_in_schema: bool = True,
+    **extra: Any,
+) -> Any
+```
+
+### Form Data and File Uploads
+```python
+from fastapi import Form, File, UploadFile
+
+def Form(
+    default: Any = Undefined,
+    *,
+    media_type: str = "application/x-www-form-urlencoded",
+    alias: Optional[str] = None,
+    title: Optional[str] = None,
+    description: Optional[str] = None,
+    gt: Optional[float] = None,
+    ge: Optional[float] = None,
+    lt: Optional[float] = None,
+    le: Optional[float] = None,
+    min_length: Optional[int] = None,
+    max_length: Optional[int] = None,
+    regex: Optional[str] = None,
+    example: Any = Undefined,
+    examples: Optional[Dict[str, Any]] = None,
+    **extra: Any,
+) -> Any
+
+def File(
+    default: Any = Undefined,
+    *,
+    media_type: str = "multipart/form-data",
+    alias: Optional[str] = None,
+    title: Optional[str] = None,
+    description: Optional[str] = None,
+    gt: Optional[float] = None,
+    ge: Optional[float] = None,
+    lt: Optional[float] = None,
+    le: Optional[float] = None,
+    min_length: Optional[int] = None,
+    max_length: Optional[int] = None,
+    example: Any = Undefined,
+    examples: Optional[Dict[str, Any]] = None,
+    **extra: Any,
+) -> Any
+```
+
+
+## Dependency Injection
+
+### Depends Function
+```python
+from fastapi import Depends
+
+def Depends(
+    dependency: Optional[Callable[..., Any]] = None,
+    *,
+    use_cache: bool = True,
+) -> Any
+```
+
+### Security Function
+```python
+from fastapi import Security
+
+def Security(
+    dependency: Optional[Callable[..., Any]] = None,
+    *,
+    scopes: Optional[Sequence[str]] = None,
+    use_cache: bool = True,
+) -> Any
+```
+
+## Security and Authentication
+
+### API Key Authentication
+```python
+from fastapi.security import APIKeyQuery, APIKeyHeader, APIKeyCookie
+
+# API key in query parameters
+api_key_query = APIKeyQuery(name="api_key", auto_error=True)
+
+# API key in headers
+api_key_header = APIKeyHeader(name="X-API-Key", auto_error=True)
+
+# API key in cookies
+api_key_cookie = APIKeyCookie(name="api_key", auto_error=True)
+```
+
+### HTTP Authentication
+```python
+from fastapi.security import HTTPBasic, HTTPBearer, HTTPDigest
+from fastapi.security.http import HTTPBasicCredentials, HTTPAuthorizationCredentials
+
+# HTTP Basic authentication
+basic_auth = HTTPBasic(auto_error=True)
+
+# HTTP Bearer token
+bearer_auth = HTTPBearer(auto_error=True)
+
+# HTTP Digest authentication
+digest_auth = HTTPDigest(auto_error=True)
+```
+
+### OAuth2 Authentication
+```python
+from fastapi.security import OAuth2PasswordBearer, OAuth2AuthorizationCodeBearer
+from fastapi.security.oauth2 import OAuth2PasswordRequestForm, SecurityScopes
+
+# OAuth2 password bearer
+oauth2_scheme = OAuth2PasswordBearer(
+    tokenUrl="token",
+    scopes={"read": "Read access", "write": "Write access"},
+    auto_error=True
+)
+
+# OAuth2 authorization code
+oauth2_code = OAuth2AuthorizationCodeBearer(
+    authorizationUrl="https://example.com/auth",
+    tokenUrl="https://example.com/token",
+    auto_error=True
+)
+```
+
+### OpenID Connect
+```python
+from fastapi.security.open_id_connect_url import OpenIdConnect
+
+openid_connect = OpenIdConnect(
+    openIdConnectUrl="https://example.com/.well-known/openid_configuration",
+    auto_error=True
+)
+```
+
+## Response Types
+
+### Standard Responses
+```python
+from fastapi.responses import (
+    Response, JSONResponse, HTMLResponse, PlainTextResponse,
+    RedirectResponse, StreamingResponse, FileResponse
+)
+
+# JSON response (default)
+return JSONResponse(content={"message": "Hello World"})
+
+# HTML response
+return HTMLResponse(content="<html><body><h1>Hello World</h1></body></html>")
+
+# Plain text response
+return PlainTextResponse(content="Hello World")
+
+# Redirect response
+return RedirectResponse(url="https://example.com")
+
+# File response
+return FileResponse(path="/path/to/file.pdf", filename="download.pdf")
+
+# Streaming response
+def generate():
+    for i in range(1000):
+        yield f"data chunk {i}\n"
+
+return StreamingResponse(generate(), media_type="text/plain")
+```
+
+### High-Performance JSON Responses
+```python
+from fastapi.responses import UJSONResponse, ORJSONResponse
+
+# Ultra-fast JSON with ujson
+return UJSONResponse(content={"message": "Fast JSON"})
+
+# Ultra-fast JSON with orjson
+return ORJSONResponse(content={"message": "Faster JSON"})
+```
+
+## Exception Handling
+
+### HTTP Exceptions
+```python
+from fastapi import HTTPException
+from fastapi.exceptions import (
+    RequestValidationError, WebSocketRequestValidationError,
+    ResponseValidationError, FastAPIError
+)
+
+# Raise HTTP exception
+raise HTTPException(
+    status_code=404,
+    detail="Item not found",
+    headers={"X-Error": "There goes my error"}
+)
+
+# Custom exception handler
+from fastapi.exception_handlers import (
+    http_exception_handler,
+    request_validation_exception_handler,
+    validation_exception_handler
+)
+
+@app.exception_handler(HTTPException)
+async def custom_http_exception_handler(request, exc):
+    return await http_exception_handler(request, exc)
+```
+
+### WebSocket Exceptions
+```python
+from fastapi import WebSocketException
+
+# Raise WebSocket exception
+raise WebSocketException(code=1008, reason="Invalid data")
+```
+
+
+## WebSocket Support
+
+### WebSocket Endpoint
+```python
+from fastapi import WebSocket, WebSocketDisconnect
+from fastapi.websockets import WebSocketState
+
+@app.websocket("/ws")
+async def websocket_endpoint(websocket: WebSocket):
+    await websocket.accept()
+    try:
+        while True:
+            data = await websocket.receive_text()
+            await websocket.send_text(f"Message: {data}")
+    except WebSocketDisconnect:
+        print("Client disconnected")
+```
+
+### WebSocket Methods
+```python
+# Connection management
+await websocket.accept(subprotocol=None)
+await websocket.close(code=1000)
+
+# Receiving data
+data = await websocket.receive()  # Any message
+text = await websocket.receive_text()  # Text message
+bytes_data = await websocket.receive_bytes()  # Binary message
+json_data = await websocket.receive_json()  # JSON message
+
+# Sending data
+await websocket.send(message)
+await websocket.send_text(data)
+await websocket.send_bytes(data)
+await websocket.send_json(data)
+
+# Iterating over messages
+async for message in websocket.iter_text():
+    print(message)
+
+async for message in websocket.iter_bytes():
+    print(message)
+
+async for message in websocket.iter_json():
+    print(message)
+```
+
+### WebSocket States
+```python
+from fastapi.websockets import WebSocketState
+
+# WebSocketState.CONNECTING
+# WebSocketState.CONNECTED
+# WebSocketState.DISCONNECTED
+
+if websocket.client_state == WebSocketState.CONNECTED:
+    await websocket.send_text("Hello")
+```
+
+## Background Tasks
+
+### Background Task Execution
+```python
+from fastapi import BackgroundTasks
+
+def write_log(message: str):
+    with open("log.txt", mode="a") as log:
+        log.write(message)
+
+@app.post("/send-notification/")
+async def send_notification(email: str, background_tasks: BackgroundTasks):
+    background_tasks.add_task(write_log, f"Notification sent to {email}")
+    return {"message": "Notification sent in the background"}
+```
+
+## Testing
+
+### TestClient
+```python
+from fastapi.testclient import TestClient
+
+client = TestClient(app)
+
+# HTTP requests
+response = client.get("/")
+response = client.post("/items/", json={"name": "Foo"})
+response = client.put("/items/1", json={"name": "Bar"})
+response = client.delete("/items/1")
+
+# WebSocket testing
+with client.websocket_connect("/ws") as websocket:
+    websocket.send_text("Hello")
+    data = websocket.receive_text()
+    assert data == "Message: Hello"
+
+# File uploads
+with open("test.txt", "rb") as f:
+    response = client.post("/upload/", files={"file": f})
+
+# Form data
+response = client.post("/form/", data={"username": "testuser"})
+```
+
+## Middleware
+
+### CORS Middleware
+```python
+from fastapi.middleware.cors import CORSMiddleware
+
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=["https://example.com"],
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+```
+
+### Other Middleware
+```python
+from fastapi.middleware.gzip import GZipMiddleware
+from fastapi.middleware.httpsredirect import HTTPSRedirectMiddleware
+from fastapi.middleware.trustedhost import TrustedHostMiddleware
+
+# GZip compression
+app.add_middleware(GZipMiddleware, minimum_size=1000)
+
+# HTTPS redirect
+app.add_middleware(HTTPSRedirectMiddleware)
+
+# Trusted host validation
+app.add_middleware(
+    TrustedHostMiddleware,
+    allowed_hosts=["example.com", "*.example.com"]
+)
+```
+
+## Utilities
+
+### JSON Encoder
+```python
+from fastapi.encoders import jsonable_encoder
+from datetime import datetime
+from pydantic import BaseModel
+
+class Item(BaseModel):
+    name: str
+    timestamp: datetime
+
+item = Item(name="Foo", timestamp=datetime.now())
+json_data = jsonable_encoder(item)
+```
+
+### Static Files
+```python
+from fastapi.staticfiles import StaticFiles
+
+app.mount("/static", StaticFiles(directory="static"), name="static")
+```
+
+## Status Codes
+
+```python
+from fastapi import status
+
+@app.post("/items/", status_code=status.HTTP_201_CREATED)
+def create_item():
+    return {"message": "Item created"}
+
+# Common status codes
+status.HTTP_200_OK
+status.HTTP_201_CREATED
+status.HTTP_204_NO_CONTENT
+status.HTTP_400_BAD_REQUEST
+status.HTTP_401_UNAUTHORIZED
+status.HTTP_403_FORBIDDEN
+status.HTTP_404_NOT_FOUND
+status.HTTP_422_UNPROCESSABLE_ENTITY
+status.HTTP_500_INTERNAL_SERVER_ERROR
+```
+
+
+## Complete Usage Examples
+
+### Basic FastAPI Application
+```python
+from fastapi import FastAPI, HTTPException
+from pydantic import BaseModel
+from typing import Optional
+
+app = FastAPI(title="My API", version="1.0.0")
+
+class Item(BaseModel):
+    name: str
+    description: Optional[str] = None
+    price: float
+    tax: Optional[float] = None
+
+items_db = []
+
+@app.get("/")
+def read_root():
+    return {"Hello": "World"}
+
+@app.get("/items/{item_id}")
+def read_item(item_id: int, q: Optional[str] = None):
+    if item_id >= len(items_db):
+        raise HTTPException(status_code=404, detail="Item not found")
+    return {"item_id": item_id, "q": q, "item": items_db[item_id]}
+
+@app.post("/items/")
+def create_item(item: Item):
+    items_db.append(item)
+    return item
+
+@app.put("/items/{item_id}")
+def update_item(item_id: int, item: Item):
+    if item_id >= len(items_db):
+        raise HTTPException(status_code=404, detail="Item not found")
+    items_db[item_id] = item
+    return item
+
+@app.delete("/items/{item_id}")
+def delete_item(item_id: int):
+    if item_id >= len(items_db):
+        raise HTTPException(status_code=404, detail="Item not found")
+    return items_db.pop(item_id)
+```
+
+### Advanced Application with Authentication
+```python
+from fastapi import FastAPI, Depends, HTTPException, status
+from fastapi.security import OAuth2PasswordBearer, OAuth2PasswordRequestForm
+from pydantic import BaseModel
+from typing import Optional
+import jwt
+from datetime import datetime, timedelta
+
+app = FastAPI()
+
+oauth2_scheme = OAuth2PasswordBearer(tokenUrl="token")
+
+class Token(BaseModel):
+    access_token: str
+    token_type: str
+
+class User(BaseModel):
+    username: str
+    email: Optional[str] = None
+    full_name: Optional[str] = None
+    disabled: Optional[bool] = None
+
+def verify_token(token: str = Depends(oauth2_scheme)):
+    try:
+        payload = jwt.decode(token, "secret", algorithms=["HS256"])
+        username: str = payload.get("sub")
+        if username is None:
+            raise HTTPException(
+                status_code=status.HTTP_401_UNAUTHORIZED,
+                detail="Could not validate credentials",
+                headers={"WWW-Authenticate": "Bearer"},
+            )
+        return username
+    except jwt.PyJWTError:
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="Could not validate credentials",
+            headers={"WWW-Authenticate": "Bearer"},
+        )
+
+@app.post("/token", response_model=Token)
+async def login(form_data: OAuth2PasswordRequestForm = Depends()):
+    # Authenticate user (simplified)
+    if form_data.username == "testuser" and form_data.password == "testpass":
+        access_token_expires = timedelta(minutes=30)
+        access_token = jwt.encode(
+            {"sub": form_data.username, "exp": datetime.utcnow() + access_token_expires},
+            "secret",
+            algorithm="HS256"
+        )
+        return {"access_token": access_token, "token_type": "bearer"}
+    raise HTTPException(
+        status_code=status.HTTP_401_UNAUTHORIZED,
+        detail="Incorrect username or password",
+        headers={"WWW-Authenticate": "Bearer"},
+    )
+
+@app.get("/users/me", response_model=User)
+async def read_users_me(current_user: str = Depends(verify_token)):
+    return User(username=current_user, email="test@example.com")
+
+@app.get("/protected")
+async def protected_route(current_user: str = Depends(verify_token)):
+    return {"message": f"Hello {current_user}, this is a protected route"}
+```
+
+### File Upload Example
+```python
+from fastapi import FastAPI, File, UploadFile, Form
+from typing import List
+import shutil
+
+app = FastAPI()
+
+@app.post("/upload-file/")
+async def upload_file(file: UploadFile = File(...)):
+    with open(f"uploads/{file.filename}", "wb") as buffer:
+        shutil.copyfileobj(file.file, buffer)
+    return {"filename": file.filename, "content_type": file.content_type}
+
+@app.post("/upload-files/")
+async def upload_files(files: List[UploadFile] = File(...)):
+    filenames = []
+    for file in files:
+        with open(f"uploads/{file.filename}", "wb") as buffer:
+            shutil.copyfileobj(file.file, buffer)
+        filenames.append(file.filename)
+    return {"filenames": filenames}
+
+@app.post("/upload-with-form/")
+async def upload_with_form(
+    file: UploadFile = File(...),
+    description: str = Form(...)
+):
+    return {
+        "filename": file.filename,
+        "description": description,
+        "content_type": file.content_type
+    }
+```
+
+### WebSocket Chat Example
+```python
+from fastapi import FastAPI, WebSocket, WebSocketDisconnect
+from typing import List
+
+app = FastAPI()
+
+class ConnectionManager:
+    def __init__(self):
+        self.active_connections: List[WebSocket] = []
+
+    async def connect(self, websocket: WebSocket):
+        await websocket.accept()
+        self.active_connections.append(websocket)
+
+    def disconnect(self, websocket: WebSocket):
+        self.active_connections.remove(websocket)
+
+    async def send_personal_message(self, message: str, websocket: WebSocket):
+        await websocket.send_text(message)
+
+    async def broadcast(self, message: str):
+        for connection in self.active_connections:
+            await connection.send_text(message)
+
+manager = ConnectionManager()
+
+@app.websocket("/ws/{client_id}")
+async def websocket_endpoint(websocket: WebSocket, client_id: int):
+    await manager.connect(websocket)
+    try:
+        while True:
+            data = await websocket.receive_text()
+            await manager.send_personal_message(f"You wrote: {data}", websocket)
+            await manager.broadcast(f"Client #{client_id} says: {data}")
+    except WebSocketDisconnect:
+        manager.disconnect(websocket)
+        await manager.broadcast(f"Client #{client_id} left the chat")
+```
+
+## Running the Application
+
+### Development Server
+```bash
+# Install uvicorn
+pip install "uvicorn[standard]"
+
+# Run the application
+uvicorn main:app --reload
+
+# Run with custom host and port
+uvicorn main:app --host 0.0.0.0 --port 8000 --reload
+```
+
+### Production Deployment
+```bash
+# With Gunicorn
+pip install gunicorn
+gunicorn main:app -w 4 -k uvicorn.workers.UvicornWorker
+
+# With Docker
+# Dockerfile
+FROM python:3.9
+WORKDIR /code
+COPY requirements.txt .
+RUN pip install -r requirements.txt
+COPY . .
+CMD ["uvicorn", "main:app", "--host", "0.0.0.0", "--port", "80"]
+```
+
+## Key Import Statements Summary
+
+```python
+# Core FastAPI
+from fastapi import (
+    FastAPI, APIRouter, Request, Response,
+    HTTPException, WebSocketException,
+    Depends, Security, BackgroundTasks,
+    status
+)
+
+# Parameter functions
+from fastapi import (
+    Path, Query, Body, Header, Cookie,
+    Form, File, UploadFile
+)
+
+# WebSocket support
+from fastapi import WebSocket, WebSocketDisconnect
+from fastapi.websockets import WebSocketState
+
+# Security
+from fastapi.security import (
+    HTTPBasic, HTTPBearer, HTTPDigest,
+    OAuth2PasswordBearer, OAuth2AuthorizationCodeBearer,
+    OAuth2PasswordRequestForm, SecurityScopes,
+    APIKeyQuery, APIKeyHeader, APIKeyCookie
+)
+
+# Responses
+from fastapi.responses import (
+    JSONResponse, HTMLResponse, PlainTextResponse,
+    RedirectResponse, StreamingResponse, FileResponse,
+    UJSONResponse, ORJSONResponse
+)
+
+# Middleware
+from fastapi.middleware.cors import CORSMiddleware
+from fastapi.middleware.gzip import GZipMiddleware
+from fastapi.middleware.httpsredirect import HTTPSRedirectMiddleware
+from fastapi.middleware.trustedhost import TrustedHostMiddleware
+
+# Testing
+from fastapi.testclient import TestClient
+
+# Utilities
+from fastapi.encoders import jsonable_encoder
+from fastapi.staticfiles import StaticFiles
+```
+
+This documentation covers the complete FastAPI API for building modern, fast web APIs with Python. FastAPI provides automatic API documentation, request/response validation, dependency injection, security, and high performance through async support.