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LangChain is a framework for building applications powered by language models. It provides abstractions for chains, agents, memory, and retrieval-augmented generation (RAG).

• Composable chains for LLM workflows
• RAG with vector store integrations (Chroma, Pinecone, pgvector)
• Agent framework with tool use
• LangSmith for debugging and monitoring

Used by developers building chatbots, RAG systems, document Q&A, and autonomous agents. The most widely adopted LLM application framework.

Open-source (MIT license). LangSmith: free tier, paid plans for teams. LangServe for deployment.

Visit LangChain official website →