PydanticAI is a Python agent framework built by the creators of Pydantic, designed to bring the same developer experience that made Pydantic the standard for Python data validation to AI agent development. With type-safe, Pydantic-native design, PydanticAI makes it easy to build reliable AI agents with structured inputs and outputs, dependency injection for testing, and streaming response support. It works with all major LLMs and integrates naturally with FastAPI and other Python ecosystem tools, making it the ideal choice for Python developers building production AI applications.