Langchain.com

LangChain is an open-source framework and engineering platform designed for developers to build, test, and deploy reliable AI agents and applications powered by large language models (LLMs). It provides modular components, pre-built architectures, and integrations with models, tools, databases, and external data sources, enabling rapid development of context-aware systems without extensive custom coding. Key elements include LLM interfaces for querying models like GPT or PaLM via simple APIs, retrieval modules for Retrieval-Augmented Generation (RAG) workflows that fetch and incorporate real-time data from documents, APIs, or vector databases to reduce hallucinations and boost accuracy, and memory capabilities that retain conversation history for coherent, multi-turn interactions. LangChain's LangGraph offers durable runtime with persistence, checkpointing, rewind, and human-in-the-loop support, while LangSmith facilitates tracing, evaluation, and deployment. Developers can chain prompts, orchestrate agents for reasoning and task decomposition, and customize behaviors through middleware for tasks like data compression or sensitivity filtering. With over 90 million monthly downloads, 100k+ GitHub stars, and 1000+ integrations, it simplifies AI development across research, code generation, and search applications. The framework supports streaming, batching, and parallel execution via LangChain Expression Language (LCEL), making it ideal for production-scale workloads. LangChain empowers teams to create chatbots, summarization tools, generative question-answering systems, and more, fostering innovation in agentic AI while maintaining framework neutrality for existing stacks.[1][2][3][5][6]