Pydantic AI vs LangGraph (2026)

Short answer: Pydantic AI is best for typed Python agents with structured output: we tested it (7.7/10) and tool calls worked first time offline. LangGraph is best when you need explicit control over state, branching and persistence via graphs.

Pydantic AI vs LangGraph: verdict, side-by-side table and sources.

Pydantic AI 2.56.0LangGraph 1.2.15
What it isOpen-source Python agent framework from the Pydantic team.LangChain's MIT-licensed framework for building stateful, controllable agents as graphs ("Build resilient agents").
PricingOpen sourceOpen source
Latest release we track2.56.0 (13 Oct 2026)1.2.15 (12 Oct 2026)
AgentPick Score88/100 · Hands-on tested 7.7/1090/100
Try itOfficial source ↗Official source ↗

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Our take

Pydantic AI is best for typed Python agents with structured output: we tested it (7.7/10) and tool calls worked first time offline. LangGraph is best when you need explicit control over state, branching and persistence via graphs.

The sourced entries

Pydantic AI 2.56.0 logoPydantic AI 2.56.0

Agent building AgentPick Score 88/100 · #11 in category Hands-on tested · 7.7/10 (15 Oct 2026) Released 13 Oct 2026

Verdict: The cleanest typed-Python agent framework we've tried. In our offline test, tool calls and structured output worked on the first run with no API key, using the built-in TestModel. Live-model quality isn't tested yet.

Test notes: Hand-tested on 15 Oct 2026: installed pydantic-ai-slim==2.56.0 into a clean Python 3.13 venv, built an agent with one tool and a typed Pydantic output, and ran it with the built-in offline TestModel (no API key). The tool was called and a validated structured output came back in about 0.01 s. Downside: it prints a large observability/Logfire banner on run unless PYDANTIC_AI_NO_BANNER=1. Not yet run against a live LLM, so output quality is scored conservatively.

Pricing: Open source

Source: github.com · Last checked 15 Oct 2026

LangGraph 1.2.15 logoLangGraph 1.2.15

Agent building AgentPick Score 90/100 · #4 in category Released 12 Oct 2026

Verdict: The low-level choice when you need explicit control over agent state, branching and persistence. More code than CrewAI's role-based crews, but more control.

Test notes: The verdict is based on the linked public sources only.

Pricing: Open source

Source: github.com pypi.org · Last checked 15 Oct 2026

Every row comes from the sources linked on each card. Last updated 15 Oct 2026.

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