LangChain is a software framework that helps facilitate the integration of large language models (LLMs) into applications. As a language model integration framework, LangChain's use-cases largely overlap with those of language models in general, including document analysis and summarization, chatbots, and code analysis.
History LangChain was launched in October 2022 as an open source project by Harrison Chase, while working at machine learning startup Robust Intelligence. In April 2023, LangChain had incorporated and the new startup raised over $20 million in funding at a valuation of at least $200 million from venture firm Sequoia Capital, a week after announcing a $10 million seed investment from Benchmark.
In the third quarter of 2023, the LangChain Expression Language (LCEL) was introduced, which provides a declarative way to define chains of actions.
In October 2023 LangChain introduced LangServe, a deployment tool to host LCEL code as a production-ready API.
In February 2024 LangChain released LangSmith, a closed-source observability and evaluation platform for LLM applications, and announced a US $25 million Series A led by Sequoia Capital. On 14 May 2025 the company launched LangGraph Platform into general availability, providing managed infrastructure for deploying long-running, stateful AI agents.
In April 2025, LangChain was featured in the Forbes AI 50 list.
On 22 October 2025, LangChain 1.0 was released as the first major version of the framework. The release introduced a new create_agent abstraction, middleware for customizing agent behavior, and standardized content blocks for model outputs. It also reduced the scope of the main package, with legacy functionality moved to langchain-classic.
Capabilities LangChain's developers highlight the framework's applicability to use-cases including chatbots, retrieval-augmented generation, document summarization, and synthetic data generation. InfoWorld described LangChain as a software development kit that simplifies the connection between large language models and external applications through a unified API. The magazine also wrote that it can be used to bring in context from sources such as PDFs, web pages, CSV files and relational databases, while making it easier for developers to change the underlying model without major code changes.
As of March 2023, LangChain included integrations with systems including Amazon, Google, and Microsoft Azure cloud storage; API wrappers for news, movie information, and weather; Bash for summarization, syntax and semantics checking, and execution of shell scripts; multiple web scraping subsystems and templates; few-shot learning prompt generation support; finding and summarizing "todo" tasks in code; Google Drive documents, spreadsheets, and presentations summarization, extraction, and creation; Google Search and Microsoft Bing web search; OpenAI, Anthropic, and Hugging Face language models; iFixit repair guides and wikis search and summarization; MapReduce for question answering, combining documents, and question generation; N-gram overlap scoring; PyPDF, pdfminer, fitz, and pymupdf for PDF file text extraction and manipulation; Python and JavaScript code generation, analysis, and debugging; Milvus vector database to store and retrieve vector embeddings; Weaviate vector database to cache embedding and data objects; Redis cache database storage; Python RequestsWrapper and other methods for API requests; SQL and NoSQL databases including JSON support; Streamlit, including for logging; text mapping for k-nearest neighbors search; time zone conversion and calendar operations; tracing and recording stack symbols in threaded and asynchronous subprocess runs; and the WolframAlpha website and SDK. As of April 2023, it can read from more than 50 document types and data sources.
LangChain tools
+Tool nameAccount required?API key required?LicencingFeaturesDocumentation URLAlpha VantageNoYesProprietaryFinancial data, analyticshttps://python.langchain.com/docs/integrations/tools/alpha_vantageApifyNoYesCommercialWeb scraping, automationhttps://python.langchain.com/docs/integrations/providers/apify/ArXivNoNoOpen SourceScientific papers, researchhttps://python.langchain.com/docs/integrations/tools/arxivAWS LambdaYesYesProprietaryServerless computinghttps://python.langchain.com/docs/integrations/tools/awslambdaBashNoNoOpen sourceShell environment accesshttps://python.langchain.com/docs/integrations/tools/bashBearly Code InterpreterNoYesCommercialRemote Python code executionhttps://python.langchain.com/docs/integrations/tools/bearlyBing SearchNoYesProprietarySearch enginehttps://python.langchain.com/docs/integrations/tools/bing_searchBrave SearchNoNoOpen sourcePrivacy-focused searchhttps://python.langchain.com/docs/integrations/tools/brave_searchChatGPT PluginsNoYesProprietaryChatGPThttps://python.langchain.com/docs/integrations/tools/chatgpt_pluginsConneryNoYesCommercialAPI actionshttps://python.langchain.com/docs/integrations/tools/conneryDall-E Image GeneratorNoYesProprietaryText-to-image generationhttps://python.langchain.com/docs/integrations/tools/dalle_image_generatorDataForSEONoYesCommercialSEO data, analyticshttps://python.langchain.com/docs/integrations/tools/dataforseoDuckDuckGo SearchNoNoOpen sourcePrivacy-focused searchhttps://python.langchain.com/docs/integrations/tools/ddgE2B Data AnalysisNoNoOpen sourceData analysishttps://python.langchain.com/docs/integrations/tools/e2b_data_analysisEden AINoYesCommercialAI tools, APIshttps://python.langchain.com/docs/integrations/tools/edenai_toolsEleven Labs Text2SpeechNoYesCommercialText-to-speechhttps://python.langchain.com/docs/integrations/tools/eleven_labs_ttsExa SearchNoYesCommercialWeb searchhttps://python.langchain.com/docs/integrations/tools/exa_searchFile SystemNoNoOpen sourceFile system interactionhttps://python.langchain.com/docs/integrations/tools/filesystemGolden QueryNoYesCommercialNatural language querieshttps://python.langchain.com/docs/integrations/tools/golden_queryGoogle Cloud Text-to-SpeechYesYesProprietaryText-to-speechhttps://python.langchain.com/docs/integrations/tools/google_cloud_texttospeechGoogle DriveYesYesProprietaryGoogle Drive accesshttps://python.langchain.com/docs/integrations/tools/google_driveGoogle FinanceYesYesProprietaryFinancial datahttps://python.langchain.com/docs/integrations/tools/google_financeGoogle JobsYesYesProprietaryJob searchhttps://python.langchain.com/docs/integrations/tools/google_jobsGoogle LensYesYesProprietaryVisual search, recognitionhttps://python.langchain.com/docs/integrations/tools/google_lensGoogle PlacesYesYesProprietaryLocation-based serviceshttps://python.langchain.com/docs/integrations/tools/google_placesGoogle ScholarYesYesProprietaryScholarly article searchhttps://python.langchain.com/docs/integrations/tools/google_scholarGoogle SearchYesYesProprietarySearch enginehttps://python.langchain.com/docs/integrations/tools/google_searchGoogle SerperNoYesCommercialSERP scrapinghttps://python.langchain.com/docs/integrations/tools/google_serperGoogle TrendsYesYesProprietaryTrend datahttps://python.langchain.com/docs/integrations/tools/google_trendsGradioNoNoOpen sourceMachine learning UIshttps://python.langchain.com/docs/integrations/tools/gradio_toolsGraphQLNoNoOpen sourceAPI querieshttps://python.langchain.com/docs/integrations/tools/graphqlHuggingFace HubNoNoOpen sourceHugging Face models, datasetshttps://python.langchain.com/docs/integrations/tools/huggingface_toolsHuman as a toolNoNoN/AHuman inputhttps://python.langchain.com/docs/integrations/tools/human_toolsIFTTT WebHooksNoYesCommercialWeb service automationhttps://python.langchain.com/docs/integrations/tools/iftttIonic ShoppingNoYesCommercialShoppinghttps://python.langchain.com/docs/integrations/tools/ionic_shoppingLemon AgentNoYesCommercialLemon AI interactionhttps://python.langchain.com/docs/integrations/tools/lemonaiMemorizeNoNoOpen sourceFine-tune LLM to memorize information using unsupervised learninghttps://python.langchain.com/docs/integrations/tools/memorizeNucliaNoYesCommercialIndexing of unstructured datahttps://python.langchain.com/docs/integrations/tools/nucliaOpenWeatherMapNoYesCommercialWeather datahttps://python.langchain.com/docs/integrations/tools/openweathermapPolygon Stock Market APINoYesCommercialStock market datahttps://python.langchain.com/docs/integrations/tools/polygonPubMedNoNoOpen sourceBiomedical literaturehttps://python.langchain.com/docs/integrations/tools/pubmedPython REPLNoNoOpen sourcePython shellhttps://python.langchain.com/docs/integrations/tools/pythonReddit SearchNoNoOpen sourceReddit searchhttps://python.langchain.com/docs/integrations/tools/reddit_searchRequestsNoNoOpen sourceHTTP requestshttps://python.langchain.com/docs/integrations/tools/requestsSceneXplainNoNoOpen sourceModel explanationshttps://python.langchain.com/docs/integrations/tools/sceneXplainSearchNoNoOpen sourceQuery various search serviceshttps://python.langchain.com/docs/integrations/tools/search_toolsSearchApiNoYesCommercialQuery various search serviceshttps://python.langchain.com/docs/integrations/tools/searchapiSearxNGNoNoOpen sourcePrivacy-focused searchhttps://python.langchain.com/docs/integrations/tools/searx_searchSemantic Scholar APINoNoOpen sourceAcademic paper searchhttps://python.langchain.com/docs/integrations/tools/semanticscholarSerpAPINoYesCommercialSearch engine results page scrapinghttps://python.langchain.com/docs/integrations/tools/serpapiStackExchangeNoNoOpen sourceStack Exchange accesshttps://python.langchain.com/docs/integrations/tools/stackexchangeTavily SearchNoYesCommercialQuestion answeringhttps://python.langchain.com/docs/integrations/tools/tavily_searchTwilioNoYesCommercialCommunication APIshttps://python.langchain.com/docs/integrations/tools/twilioWikidataNoNoOpen sourceStructured data accesshttps://python.langchain.com/docs/integrations/tools/wikidataWikipediaNoNoOpen sourceWikipedia accesshttps://python.langchain.com/docs/integrations/tools/wikipediaWolfram AlphaNoYesProprietaryComputational knowledgehttps://python.langchain.com/docs/integrations/tools/wolfram_alphaYahoo Finance NewsNoYesCommercialFinancial newshttps://python.langchain.com/docs/integrations/tools/yahoo_finance_newsYoutubeNoYesCommercialYouTube accesshttps://python.langchain.com/docs/integrations/tools/youtubeZapier Natural Language ActionsNoYesCommercialWorkflow automationhttps://python.langchain.com/docs/integrations/tools/zapier
See also CrewAI — framework for building and coordinating multi-agent AI systems Theia AI — framework for integrating AI capabilities and agents into development environments Lists of open-source artificial intelligence software
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