| name | pydantic-ai-python |
| description | Build AI agents with PydanticAI — tools, structured output, multi-provider, streaming, multi-agent delegation, MCP, capabilities, evals, graphs. Use when working with pydantic_ai, pydantic-ai, Agent, RunContext, tool decorator, output_type, deps_type, capabilities, or any PydanticAI agent pattern in Python. |
PydanticAI
Python agent framework by the Pydantic team. Model-agnostic, type-safe, dependency-injected.
Installation
uv add pydantic-ai
uv add 'pydantic-ai[openai]'
uv add 'pydantic-ai[logfire]'
Python 3.9+. Requires pydantic v2.
Quick start
from pydantic_ai import Agent
agent = Agent('anthropic:claude-sonnet-4-6', instructions='Be concise.')
result = agent.run_sync('Hello')
print(result.output)
Architecture at a glance
An Agent bundles: instructions, tools/toolsets, output type, dependency type, model, model settings, and capabilities.
Agents are generic: Agent[DepsType, OutputType]. They're designed for reuse — instantiate globally like a FastAPI app.
Running agents
Five modes: run() (async), run_sync(), run_stream() / run_stream_sync(), run_stream_events(), iter() (graph node iteration).
All return result.output typed to your output_type.
Reference files
- agents-and-dependencies.md — Agent construction, instructions, deps, run modes, conversations
- tools-and-toolsets.md — Function tools, toolsets, deferred tools, built-in tools, MCP, common tools
- output-and-streaming.md — Structured output, streaming, validation, output functions
- models-and-providers.md — Provider strings, model settings, fallback, custom models
- capabilities-and-hooks.md — Composable capabilities, hooks, agent specs (YAML/JSON)
- multi-agent.md — Delegation, handoff, programmatic multi-agent patterns
- advanced.md — Multimodal input, thinking, graphs, evals, durable execution, embeddings, extensibility, harness
