LangChain

The Python/JS framework for chains, agents and RAG pipelines

langchain.com · Free open source; LangSmith free tier

LangChain (and LangGraph) orchestrates LLM apps — retrieval pipelines, multi-step agents, tool use — with the largest ecosystem of integrations.

Capabilities

Capabilities

  • LangGraph agent orchestration, retrievers/loaders for everything, LangSmith observability

Best for

  • Python-first AI clones with complex agent/RAG flows

Not for

  • Simple chat features (direct SDK or AI SDK is less abstraction)