LangChain

Last updated
LangChain
Developer(s) Harrison Chase
Initial releaseOctober 2022
Stable release
0.1.16 [1] / 11 April 2024;16 months ago (11 April 2024)
Repository github.com/langchain-ai/langchain
Written in Python and JavaScript
Type Software framework for large language model application development
License MIT License
Website LangChain.com

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. [2]

Contents

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. [3] [4]

In the third quarter of 2023, the LangChain Expression Language (LCEL) was introduced, which provides a declarative way to define chains of actions. [5] [6]

In October 2023 LangChain introduced LangServe, a deployment tool to host LCEL code as a production-ready API. [7]

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. [8] On 14 May 2025 the company launched LangGraph Platform into general availability, providing managed infrastructure for deploying long-running, stateful AI agents. [9]

Capabilities

LangChain's developers highlight the framework's applicability to use-cases including chatbots, [10] retrieval-augmented generation, [11] document summarization, [12] and synthetic data generation. [13]

As of March 2023, LangChain included integrations with systems including Amazon, Google, and Microsoft Azure cloud storage; [14] 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; [15] 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 [16] to store and retrieve vector embeddings; Weaviate vector database [17] 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 Wolfram Alpha website and SDK. [18] As of April 2023, it can read from more than 50 document types and data sources. [19]

LangChain tools

Tool nameAccount required?API key required?LicencingFeaturesDocumentation URL
Alpha VantageNoYesProprietaryFinancial data, analyticshttps://python.langchain.com/docs/integrations/tools/alpha_vantage
ApifyNoYesCommercialWeb scraping, automationhttps://python.langchain.com/docs/integrations/providers/apify/
ArXivNoNoOpen SourceScientific papers, researchhttps://python.langchain.com/docs/integrations/tools/arxiv
AWS LambdaYesYesProprietaryServerless computinghttps://python.langchain.com/docs/integrations/tools/awslambda
BashNoNoOpen sourceShell environment accesshttps://python.langchain.com/docs/integrations/tools/bash
Bearly Code InterpreterNoYesCommercialRemote Python code executionhttps://python.langchain.com/docs/integrations/tools/bearly
Bing SearchNoYesProprietarySearch enginehttps://python.langchain.com/docs/integrations/tools/bing_search
Brave SearchNoNoOpen sourcePrivacy-focused searchhttps://python.langchain.com/docs/integrations/tools/brave_search
ChatGPT PluginsNoYesProprietaryChatGPThttps://python.langchain.com/docs/integrations/tools/chatgpt_plugins
ConneryNoYesCommercialAPI actionshttps://python.langchain.com/docs/integrations/tools/connery
Dall-E Image GeneratorNoYesProprietaryText-to-image generationhttps://python.langchain.com/docs/integrations/tools/dalle_image_generator
DataForSEONoYesCommercialSEO data, analyticshttps://python.langchain.com/docs/integrations/tools/dataforseo
DuckDuckGo SearchNoNoOpen sourcePrivacy-focused searchhttps://python.langchain.com/docs/integrations/tools/ddg
E2B Data AnalysisNoNoOpen sourceData analysishttps://python.langchain.com/docs/integrations/tools/e2b_data_analysis
Eden AINoYesCommercialAI tools, APIshttps://python.langchain.com/docs/integrations/tools/edenai_tools
Eleven Labs Text2SpeechNoYesCommercialText-to-speechhttps://python.langchain.com/docs/integrations/tools/eleven_labs_tts
Exa SearchNoYesCommercialWeb searchhttps://python.langchain.com/docs/integrations/tools/exa_search
File SystemNoNoOpen sourceFile system interactionhttps://python.langchain.com/docs/integrations/tools/filesystem
Golden QueryNoYesCommercialNatural language querieshttps://python.langchain.com/docs/integrations/tools/golden_query
Google Cloud Text-to-SpeechYesYesProprietaryText-to-speechhttps://python.langchain.com/docs/integrations/tools/google_cloud_texttospeech
Google DriveYesYesProprietaryGoogle Drive accesshttps://python.langchain.com/docs/integrations/tools/google_drive
Google FinanceYesYesProprietaryFinancial datahttps://python.langchain.com/docs/integrations/tools/google_finance
Google JobsYesYesProprietaryJob searchhttps://python.langchain.com/docs/integrations/tools/google_jobs
Google LensYesYesProprietaryVisual search, recognitionhttps://python.langchain.com/docs/integrations/tools/google_lens
Google PlacesYesYesProprietaryLocation-based serviceshttps://python.langchain.com/docs/integrations/tools/google_places
Google ScholarYesYesProprietaryScholarly article searchhttps://python.langchain.com/docs/integrations/tools/google_scholar
Google SearchYesYesProprietarySearch enginehttps://python.langchain.com/docs/integrations/tools/google_search
Google SerperNoYesCommercialSERP scrapinghttps://python.langchain.com/docs/integrations/tools/google_serper
Google TrendsYesYesProprietaryTrend datahttps://python.langchain.com/docs/integrations/tools/google_trends
GradioNoNoOpen sourceMachine learning UIshttps://python.langchain.com/docs/integrations/tools/gradio_tools
GraphQLNoNoOpen sourceAPI querieshttps://python.langchain.com/docs/integrations/tools/graphql
HuggingFace HubNoNoOpen sourceHugging Face models, datasetshttps://python.langchain.com/docs/integrations/tools/huggingface_tools
Human as a toolNoNoN/AHuman inputhttps://python.langchain.com/docs/integrations/tools/human_tools
IFTTT WebHooksNoYesCommercialWeb service automationhttps://python.langchain.com/docs/integrations/tools/ifttt
Ionic ShoppingNoYesCommercialShoppinghttps://python.langchain.com/docs/integrations/tools/ionic_shopping
Lemon AgentNoYesCommercialLemon AI interactionhttps://python.langchain.com/docs/integrations/tools/lemonai
MemorizeNoNoOpen sourceFine-tune LLM to memorize information using unsupervised learninghttps://python.langchain.com/docs/integrations/tools/memorize
NucliaNoYesCommercialIndexing of unstructured datahttps://python.langchain.com/docs/integrations/tools/nuclia
OpenWeatherMapNoYesCommercialWeather datahttps://python.langchain.com/docs/integrations/tools/openweathermap
Polygon Stock Market APINoYesCommercialStock market datahttps://python.langchain.com/docs/integrations/tools/polygon
PubMedNoNoOpen sourceBiomedical literaturehttps://python.langchain.com/docs/integrations/tools/pubmed
Python REPLNoNoOpen sourcePython shellhttps://python.langchain.com/docs/integrations/tools/python
Reddit SearchNoNoOpen sourceReddit searchhttps://python.langchain.com/docs/integrations/tools/reddit_search
RequestsNoNoOpen sourceHTTP requestshttps://python.langchain.com/docs/integrations/tools/requests
SceneXplainNoNoOpen sourceModel explanationshttps://python.langchain.com/docs/integrations/tools/sceneXplain
SearchNoNoOpen sourceQuery various search serviceshttps://python.langchain.com/docs/integrations/tools/search_tools
SearchApiNoYesCommercialQuery various search serviceshttps://python.langchain.com/docs/integrations/tools/searchapi
SearxNGNoNoOpen sourcePrivacy-focused searchhttps://python.langchain.com/docs/integrations/tools/searx_search
Semantic Scholar APINoNoOpen sourceAcademic paper searchhttps://python.langchain.com/docs/integrations/tools/semanticscholar
SerpAPINoYesCommercialSearch engine results page scrapinghttps://python.langchain.com/docs/integrations/tools/serpapi
StackExchangeNoNoOpen sourceStack Exchange accesshttps://python.langchain.com/docs/integrations/tools/stackexchange
Tavily SearchNoYesCommercialQuestion answeringhttps://python.langchain.com/docs/integrations/tools/tavily_search
TwilioNoYesCommercialCommunication APIshttps://python.langchain.com/docs/integrations/tools/twilio
WikidataNoNoOpen sourceStructured data accesshttps://python.langchain.com/docs/integrations/tools/wikidata
WikipediaNoNoOpen sourceWikipedia accesshttps://python.langchain.com/docs/integrations/tools/wikipedia
Wolfram AlphaNoYesProprietaryComputational knowledgehttps://python.langchain.com/docs/integrations/tools/wolfram_alpha
Yahoo Finance NewsNoYesCommercialFinancial newshttps://python.langchain.com/docs/integrations/tools/yahoo_finance_news
YoutubeNoYesCommercialYouTube accesshttps://python.langchain.com/docs/integrations/tools/youtube
Zapier Natural Language ActionsNoYesCommercialWorkflow automationhttps://python.langchain.com/docs/integrations/tools/zapier

References

  1. ↑ "Release 0.1.16". 11 April 2024. Retrieved 23 April 2024.
  2. ↑ Buniatyan, Davit (2023). "Code Understanding Using LangChain". Activeloop.
  3. ↑ Palazzolo, Stephanie (2023-04-13). "AI startup LangChain taps Sequoia to lead funding round at a valuation of at least $200 million". Business Insider. Archived from the original on 2023-04-18. Retrieved 2023-04-18.
  4. ↑ Griffith, Erin; Metz, Cade (2023-03-14). "'Let 1,000 Flowers Bloom': A.I. Funding Frenzy Escalates". The New York Times. ISSN   0362-4331. Archived from the original on 2023-04-18. Retrieved 2023-04-18.
  5. ↑ Mansurova, Mariya (2023-10-30). "Topic Modelling in production: Leveraging LangChain to move from ad-hoc Jupyter Notebooks to production modular service". towardsdatascience.com. Retrieved 2024-07-08.
  6. ↑ "LangChain Expression Language". langchain.dev. 2023-08-01. Retrieved 2024-07-08.
  7. ↑ "Introducing LangServe, the best way to deploy your LangChains". LangChain Blog. 2023-10-12. Retrieved 2023-10-17.
  8. ↑ "Announcing the General Availability of LangSmith and Our Series A Led By Sequoia Capital". LangChain Blog. 2024-02-15. Retrieved 2025-08-03.
  9. ↑ "LangGraph Platform is now Generally Available: Deploy & manage long-running, stateful Agents". LangChain Blog. 2025-05-14. Retrieved 2025-08-03.
  10. ↑ "Chatbots | 🦜️🔗 Langchain". python.langchain.com. Archived from the original on 2024-03-14. Retrieved 2023-11-26.
  11. ↑ "Retrieval-augmented generation (RAG) | 🦜️🔗 Langchain". python.langchain.com. Archived from the original on 2024-03-28. Retrieved 2023-11-26.
  12. ↑ "Summarization | 🦜️🔗 Langchain". python.langchain.com. Archived from the original on 2024-01-06. Retrieved 2023-11-26.
  13. ↑ "Synthetic data generation | 🦜️🔗 Langchain". python.langchain.com. Archived from the original on 2024-03-07. Retrieved 2023-11-26.
  14. ↑ "Azure Cognitive Search and LangChain: A Seamless Integration for Enhanced Vector Search Capabilities". TECHCOMMUNITY.MICROSOFT.COM. Retrieved 2024-08-31.
  15. ↑ "Best Alternative AI Content Strategies and LLM Frameworks". Medium. 2024-08-31. Retrieved 2024-08-31.
  16. ↑ "Milvus — LangChain". python.langchain.com. Retrieved 2023-10-29.
  17. ↑ "Weaviate". python.langchain.com. Retrieved 2024-01-17.
  18. ↑ Hug, Daniel Patrick (2023-03-08). "Hierarchical topic tree of LangChain's integrations" (PDF). GitHub. Archived from the original on 2023-04-29. Retrieved 2023-04-18.
  19. ↑ "Document Loaders — LangChain 0.0.142". python.langchain.com. Archived from the original on 2023-04-18. Retrieved 2023-04-18.
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