Pydantic AI — Agent Frameworks Platform

Pydantic AI is a Python agent framework built by the creators of Pydantic — the validation library used in over 90% of Python AI codebases. It leverages Python type hints to make every agent input, output, and tool call type-safe, with automatic schema validation and self-correction when LLM outputs don't match the expected structure.

Core features include structured output validation (the LLM is forced to return exactly the schema you specify, with retries on failure), tool registration via decorators that auto-generate JSON schemas, dependency injection for testable agents, and seamless integration with Pydantic Logfire for real-time tracing, performance monitoring, and cost tracking.

Pydantic AI is fully free and open-source (MIT license, 16.5K+ GitHub stars). It's positioned as the type-safety-first alternative to LangChain/LangGraph for Python developers who already know Pydantic — minimal learning curve, native async streaming, and small dependency footprint. Latest release v1.85.1 shipped April 22, 2026.