The largest community building the future of LLM apps

LangChain’s flexible abstractions and AI-first toolkit make it the #1 choice for developers when building with GenAI.

LangChain keeps pace with 
the cutting edge, so you can too. Join 100k+ builders who standardize development in LangChain's Python and TypeScript frameworks.

Augment the power 
of LLMs with your data

LangChain helps connect LLMs to your company’s private sources 
of data and APIs to create context-aware, reasoning applications.

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A complete set of interoperable and interchangeable building blocks

Leverage our comprehensive library of components that together make up sophisticated, end-to-end applications. Want to change your model? Future-proof your application by making vendor optionality part of your LLM infrastructure design.

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Get customizability and control with a durable runtime baked in

LangChain Expression Language (LCEL) lets you build your app in a truly composable way, allowing you to customize it as you see fit. The protocol supports parallelization, fallbacks, batch, streaming, and async all out-of-the-box, freeing you to focus on what matters.

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Smart connections to any source of data or knowledge

Need turnkey observability?

LangSmith shines a light into application behavior and performance. Get prompt-level visibility coupled with tools to debug, test, evaluate, deploy, and monitor your applications with your team.

Why choose LangChain?

LangChain is easy to get started with and gives you choice, flexibility, and power as you scale.

2,600+ contributors
The biggest community of any LLM-centric developer framework.
600+ integrations
Providing the largest library of pluggable integrations.
From 0 to 100
Simple to get started, yet robust enough 
for production. LCEL and LangServe give 
you control and a fast path to deploy.
Over 100 templates
Dozens of pre-built examples to get you 
on your way faster.

One framework. 
Infinite use cases.

Ready to start shipping 
reliable GenAI apps faster?

LangChain and LangSmith are critical parts of the reference 
architecture to get you from prototype to production.