python-fastapi

# FastAPI - Modern Python Web APIs FastAPI is a modern, fast web framework for building APIs with Python, using standard Python type hints. FastAPI automatically validates requests, generates OpenAPI documentation, and provides excellent developer experience. ## Quick Start ### Basic Application ```python from fastapi import FastAPI from pydantic import BaseModel app = FastAPI( title="My API", description="API for my application", version="1.0.0", ) class Item(BaseModel): name: str price: float @app.get("/") def read_root(): return {"message": "Hello World"} @app.post("/items", response_model=Item) def create_item(item: Item): return item ``` **Run with:** ```bash uvicorn main:app --reload ``` ## Core Concepts ### Request & Response Models Use Pydantic models for automatic validation and serialization: ```python from pydantic import BaseModel, EmailStr, Field class CreateUserRequest(BaseModel): email: EmailStr name: str = Field(min_length=1, max_length=100) age: int = Field(ge=18, le=120) class UserResponse(BaseModel): id: int email: str name: str model_config = {"from_attributes": True} # Enable ORM mode @app.post("/users", response_model=UserResponse) def create_user(user: CreateUserRequest): """Request validated, response serialized automatically""" return user ``` See `references/validation.md` for detailed validation patterns including custom validators and field constraints. ### Routers f...