Core

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<h3>The agent engineering platform.</h3>
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!npm  

LangChain is a framework for building LLM-powered applications. It helps you chain together interoperable components and third-party integrations to simplify AI application development — all while future-proofing decisions as the underlying technology evolves.

Documentation: To learn more about LangChain, check out the docs.

If you're looking for more advanced customization or agent orchestration, check out LangGraph.js. our framework for building agents and controllable workflows.

> [!NOTE]
> Looking for the Python version? Check out LangChain.

To help you ship LangChain apps to production faster, check out LangSmith. LangSmith is a unified developer platform for building, testing, and monitoring LLM applications.

⚡️ Quick Install

You can use npm, pnpm, or yarn to install LangChain.js

npm install -S langchain or pnpm install langchain or yarn add langchain

🚀 Why use LangChain?

LangChain helps developers build applications powered by LLMs through a standard interface for agents, models, embeddings, vector stores, and more.

Use LangChain for:

Real-time data augmentation. Easily connect LLMs to diverse data sources and external/internal systems, drawing from LangChain’s vast library of integrations with model providers, tools, vector stores, retrievers, and more.

Model interoperability. Swap models in and out as your engineering team experiments to find the best choice for your application’s needs. As the industry frontier evolves, adapt quickly — LangChain’s abstractions keep you moving without losing momentum.

Rapid prototyping. Quickly build and iterate on LLM applications with LangChain's modular, component-based architecture. Test different approaches and workflows without rebuilding from scratch, accelerating your development cycle.

Production-ready features. Deploy reliable applications with built-in support for monitoring, evaluation, and debugging through integrations like LangSmith. Scale with confidence using battle-tested patt

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