🧩 Best AI tools for Agent Frameworks

Libraries for building your own autonomous, tool-using AI agents.

Score = 60% editorial fit (estimated) + 20% GitHub stars + 20% HN coverage (live public signals; weight is redistributed when a signal doesn't apply). How we rank →

  1. #1
    79
    LangGraph

    Library from LangChain for building stateful, multi-actor agents as graphs.

    Pick this if you need fine-grained control over agent state and flow.

    Free, open source · ★ 43,368 GitHub · 16 HN stories / 90d

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  2. #2
    75
    CrewAI

    Python framework for orchestrating role-playing, collaborative AI agent crews.

    Pick this if you think in teams of role-based agents.

    Free, open source; paid platform · ★ 59,764 GitHub · 5 HN stories / 90d

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  3. #3
    70
    Pydantic AI

    Type-safe Python agent framework from the Pydantic team.

    Pick this if you value type safety and structured outputs.

    Free, open source · ★ 20,664 GitHub · 4 HN stories / 90d

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  4. #4
    68
    OpenAI Agents SDK

    Lightweight Python SDK for building agents with tools, handoffs and guardrails.

    Pick this if you want a minimal, official SDK with handoffs and tracing.

    Free, open source (API usage billed) · ★ 30,088 GitHub · 0 HN stories / 90d

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  5. #5
    67
    AutoGen

    Microsoft's open-source framework for multi-agent conversational applications.

    Pick this if you want multi-agent chat patterns backed by Microsoft research.

    Free, open source · ★ 61,443 GitHub · 0 HN stories / 90d

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