The Agent Engineering Platform
LangChain.js is a TypeScript framework for building LLM-powered applications. Chain together interoperable components, integrate with 20+ providers, and build agents that can handle complex tasks.
Quick Start
Get up and running with LangChain.js in minutes.Installation
Install LangChain.js with npm, pnpm, or yarn
Quickstart Guide
Build your first LLM application in 5 minutes
Core Concepts
Learn about runnables, agents, and the framework architecture
API Reference
Explore the complete API documentation
Key Features
Everything you need to build production-ready LLM applications.Agent Engineering
Build agents with LangGraph integration for complex task orchestration
Composable Runnables
Chain components together with the powerful Runnable interface
20+ Integrations
Connect to OpenAI, Anthropic, Google, and many more providers
Structured Tools
Create tools with function calling and schema validation
Memory & History
Manage conversation state and long-term memory
Streaming Support
Real-time streaming responses for better UX
Popular Guides
Learn how to build with LangChain.js.Building Agents
Create agents that can handle complex, multi-step tasks
Working with Chat Models
Learn to use chat models from any provider
Prompt Engineering
Master prompt templates and prompt optimization
Retrieval (RAG)
Build retrieval-augmented generation applications
Ecosystem
LangChain.js is part of a larger ecosystem.LangGraph
Build agents with customizable architecture and human-in-the-loop workflows
LangSmith
Debug, test, and monitor your LLM applications in production