LangChain, a Python package for building applications with large language models (LLMs), has evolved significantly over its two years of existence. Initially focused on enabling developers to build context-aware, agentic applications by connecting LLMs to external sources of computation and data, the ecosystem has since matured and expanded. LangChain now offers three key products: LangChain, an open-source library; LangGraph, a flexible orchestration framework for building agents with customizable cognitive architectures; and LangSmith, which provides testing and observability tools for production-ready LLM applications. As the generative AI ecosystem continues to grow, LangChain remains dedicated to making it easy for developers to build reliable, impactful applications using LLMs.