FastAPI

FastAPI is a modern, high-performance Python web framework created by Sebastian Ramirez, known as tiangolo, in 2018, built on top of Starlette for web handling and Pydantic for data validation, providing automatic API documentation, type safety, async support, and dependency injection with performance comparable to Node.js and Go frameworks, adopted by Microsoft, Uber, and Netflix with over seven hundred thousand weekly downloads from PyPI and an active community of contributors. The type hint integration uses Python type annotations to automatically validate request data, serialize responses, and generate interactive API documentation, with function parameter types defining query parameters, path parameters, request bodies, headers, cookies, and form data, eliminating boilerplate validation code while providing compile-time type checking through mypy and IDE auto-completion. The automatic documentation generates interactive Swagger UI and ReDoc pages directly from the API code, with request and response schemas, example values, authentication flows, and endpoint descriptions extracted from type hints and docstrings, enabling frontend developers and API consumers to explore and test endpoints without external documentation. The async and await support leverages Python asyncio for high-concurrency workloads including database queries, HTTP client calls, and WebSocket connections, with background tasks for non-blocking operations and server-sent events for real-time streaming. The dependency injection system provides a hierarchical, scoped mechanism for database sessions, authentication, configuration, and shared logic, with automatic cleanup and resource management. The testing client enables end-to-end testing. The OAuth and JWT integration provides security patterns. The SQLModel integration combines SQLAlchemy and Pydantic. Designed for Python backend developers and API engineers.