FastAPI

FastAPI is a modern, high-performance web framework for building APIs with Python 3.8+ based on standard Python type hints. In the 2026 landscape, it remains the gold standard for AI-driven backends due to its native support for asynchronous programming (ASGI) and seamless integration with Pydantic for data validation. Architecturally, FastAPI sits atop Starlette for web parts and Pydantic for data parts, achieving performance speeds comparable to Node.js and Go. Its unique selling proposition is the automatic generation of interactive OpenAPI (Swagger) and ReDoc documentation, which significantly reduces developer friction. By 2026, the ecosystem has matured to include robust support for Pydantic V2 and tight coupling with machine learning libraries like PyTorch and TensorFlow, making it the preferred choice for deploying LLMs and real-time inference engines. Its dependency injection system allows for modular, testable code, while its security utilities provide out-of-the-box support for OAuth2, JWT, and CORS, catering to enterprise-grade security requirements.