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Build context-aware reasoning applications with LangChain’s flexible abstractions and AI-first toolkits.

Core OSS libraries:

Commercial Platform:

  • LangSmith – platform for building and monitoring production-grade LLM applications

OSS extensions and apps:

  • Open SWE – open source asynchronous coding agent
  • MCP Adapters – make MCP tools compatible with LangChain and LangGraph
  • Open Canvas – document & chat-based UX for writing code or markdown. Inspired by OpenAI's Canvas (TypeScript)
  • OpenGPTs – open source version of OpenAI's GPTs API (Python)
  • Email assistant – AI assistant that helps you maintain your emails (Python)
  • LangChain + Next.js template – template LangChain.js + Next.js application
  • Social media agent – agent for sourcing, curating, and scheduling social media posts with human-in-the-loop (TypeScript)
  • Agent Protocol – our attempt at codifying the framework-agnostic APIs that are needed to serve LLM agents in production

Learn more

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Repositories

Showing 10 of 235 repositories
  • openevals Public

    Readymade evaluators for your LLM apps

    langchain-ai/openevals’s past year of commit activity
    Python 842 MIT 76 6 1 Updated Dec 18, 2025
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    langchain-ai/langchain’s past year of commit activity
    Python 122,160 MIT 20,143 196 (31 issues need help) 111 Updated Dec 18, 2025
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    langchain-ai/langchainjs’s past year of commit activity
    TypeScript 16,562 MIT 2,927 131 (8 issues need help) 32 Updated Dec 18, 2025
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    langchain-ai/docs’s past year of commit activity
    MDX 150 MIT 1,452 139 79 Updated Dec 18, 2025
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    langchain-ai/langgraphjs’s past year of commit activity
    TypeScript 2,364 MIT 363 67 18 Updated Dec 18, 2025
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    langchain-ai/langsmith-sdk’s past year of commit activity
    Python 701 MIT 170 84 25 Updated Dec 17, 2025
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    langchain-ai/langsmith-java’s past year of commit activity
    Kotlin 7 MIT 0 0 1 Updated Dec 17, 2025
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    langchain-ai/langsmith-go’s past year of commit activity
    Go 4 MIT 0 0 1 Updated Dec 17, 2025
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    langchain-ai/deepagents’s past year of commit activity
    Python 7,218 MIT 1,107 87 75 Updated Dec 17, 2025
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    Build resilient language agents as graphs.

    langchain-ai/langgraph’s past year of commit activity
    Python 22,290 MIT 3,918 171 (13 issues need help) 89 Updated Dec 18, 2025