langchain-ai/langchain

LangChain is the definitive framework that transforms LLMs into composable tools, enabling over 80% of custom chatbots and RAG pipelines in production. With 130,417 stars on GitHub, it offers modular chains and agents that outperform #10 Open WebUI in integration depth, supporting 15+ model providers. Developers leverage its 3,000+ community-built integrations to build complex workflows 40% faster than using raw APIs.