Get startedIntroductionOn this pageIntroductionLangChain is a framework for developing applications powered by language models. It enables applications that:Are context-aware: connect a language model to sources of context (prompt instructions, few shot examples, content to ground its response in, etc.)Reason: rely on a language model to reason (about how to answer based on provided context, what actions to take, etc.)The main value props of LangChain are:Components: abstractions for working with language models, along with a collection of implementations for each abstraction. Components are modular and easy-to-use, whether you are using the rest of the LangChain framework or notOff-the-shelf chains: a structured assembly of components for accomplishing specific higher-level tasksOff-the-shelf chains make it easy to get started. For complex applications, components make it easy to customize existing chains and build new ones.Get started​Here’s how to install LangChain, set up your environment, and start building.We recommend following our Quickstart guide to familiarize yourself with the framework by building your first LangChain application.Note: These docs are for the LangChain Python package. For documentation on LangChain.js, the JS/TS version, head here.Modules​LangChain provides standard, extendable interfaces and external integrations for the following modules, listed from least to most complex:Model I/O​Interface with language modelsRetrieval​Interface with application-specific dataChains​Construct sequences of callsAgents​Let chains choose which tools to use given high-level directivesMemory​Persist application state between runs of a chainCallbacks​Log and stream intermediate steps of any chainExamples, ecosystem, and resources​Use cases​Walkthroughs and best-practices for common end-to-end use cases, like:Document question answeringChatbotsAnalyzing structured dataand much more...Guides​Learn best practices for developing with LangChain.Ecosystem​LangChain is part of a rich ecosystem of tools that integrate with our framework and build on top of it. Check out our growing list of integrations and dependent repos.Additional resources​Our community is full of prolific developers, creative builders, and fantastic teachers. Check out YouTube tutorials for great tutorials from folks in the community, and Gallery for a list of awesome LangChain projects, compiled by the folks at KyroLabs.Community​Head to the Community navigator to find places to ask questions, share feedback, meet other developers, and dream about the future of LLM’s.API reference​Head to the reference section for full documentation of all classes and methods in the LangChain Python package.PreviousGet startedNextInstallationGet startedModulesExamples, ecosystem, and resourcesUse casesGuidesEcosystemAdditional resourcesCommunityAPI reference