LangChain

langchain.com

LangChain offers a comprehensive platform designed for the entire agent engineering lifecycle, enabling teams to build and ship reliable agents to production. Its open-source products include the LangChain framework for pre-built architecture and model integrations, and LangGraph for building custom agent workflows. The platform features LangSmith, which provides observability and tracing for debugging, evaluation tools to improve agent quality with test sets and feedback, and deployment infrastructure built for long-running workloads and human oversight.