fastapi

FastAPI accelerates REST API development by combining routing, Pydantic data validation, and automatic interactive documentation. You scaffold endpoints, define models, and run the server to get a production-ready service.

Pydantic validation in FastAPI enforces data types on incoming requests automatically using Python type hints. When a client sends data, FastAPI validates it against your Pydantic models before processing, rejecting invalid payloads immediately.

FastAPI supports OAuth2 and JWT authentication out of the box. You secure endpoints using dependency injection, passing validated token data to routes to manage user authentication flows across your REST API.

FastAPI supports both synchronous and asynchronous database integration alongside built-in dependency injection. You inject database sessions into endpoints, allowing ORM operations to run efficiently within your REST API project.

The best way to test FastAPI endpoints is using its built-in TestClient. You simulate requests to your routes, verifying status codes, response payloads, and Pydantic validation behavior across your REST API.

FastAPI allows you to add websockets and background tasks to a Python REST API. These features enable real-time streaming and asynchronous processing alongside standard REST endpoints within the same project structure.