Langchain is an open-source framework designed to facilitate the development and deployment of applications powered by large language models (LLMs). It provides tools and interfaces that assist developers in managing language models, building applications, and integrating external data sources for enriched functionality. With a focus on modularity, Langchain allows seamless connection of LLMs to various data environments, enhancing the models' capabilities in real-world applications. Comprehensive documentation and resources are available at their website, https://docs.langchain.com, to support developers in leveraging the framework effectively.