PydanticAI

PydanticAI

PydanticAI is Pydantic's official agent framework that brings the same philosophy of type safety and validation to AI agents. It provides a clean, model-agnostic API for defining agents with typed system prompts, tool calls with validated inputs/outputs, dependency injection, and built-in streaming.

Key Features

• Type-safe by design — agents declare input deps and output types; Pydantic validates everything
• Model-agnostic — OpenAI, Anthropic, Google Gemini, Ollama, Groq, Mistral, and more via a unified API
• Tools — decorate any Python function as a tool; types are auto-converted to JSON schema
• Dependency injection — pass services (databases, HTTP clients) to agents without global state
• Streaming — first-class async streaming for text and structured outputs
• Logfire integration — zero-config observability with Pydantic's Logfire tracing platform
• Result validation — structured output types are validated with the full Pydantic v2 engine

Quick Start

pip install pydantic-ai

from pydantic_ai import Agent

agent = Agent(
    "openai:gpt-4o-mini",
    system_prompt="You are a concise assistant.",
)

result = agent.run_sync("What is 2 + 2?")
print(result.output)  # 4

Install via ai-supply

npx ai-supply add pydantic-ai-agent-framework

Curated mirror of the open-source PydanticAI project (MIT). Install upstream from the repository.