langchain-js
Builds LLM-powered applications with LangChain.js for chat, agents, and RAG. Use when creating AI applications with chains, memory, tools, and retrieval-augmented generation in JavaScript.
npx skills add majiayu000/claude-skill-registry --skill langchain-js --agent claude-code
Same command for any agent — swap --agent for codex, cursor, copilot.
Weekly change comes from our own snapshots, not the repository page — it measures attention, not adoption.
# LangChain.js Framework for building LLM-powered applications. Provides abstractions for chat models, chains, agents, RAG, and memory with support for multiple providers. ## Quick Start ```bash npm install langchain @langchain/openai @langchain/core ``` ### Basic Chat ```typescript import { ChatOpenAI } from '@langchain/openai'; const model = new ChatOpenAI({ modelName: 'gpt-4o', temperature: 0.7, }); const response = await model.invoke('What is the capital of France?'); console.log(response.content); ``` ## Chat Models ### OpenAI ```typescript import { ChatOpenAI } from '@langchain/openai'; const model = new ChatOpenAI({ modelName: 'gpt-4o', temperature: 0, maxTokens: 1000, }); const response = await model.invoke([ { role: 'system', content: 'You are a helpful assistant.' }, { role: 'user', content: 'Hello!' }, ]); ``` ### Anthropic ```bash npm install @langchain/anthropic ``` ```typescript import { ChatAnthropic } from '@langchain/anthropic'; const model = new ChatAnthropic({ modelName: 'claude-sonnet-4-20250514', temperature: 0, }); const response = await model.invoke('Explain quantum computing'); ``` ### Google (Gemini) ```bash npm install @langchain/google-genai ``` ```typesc
- Quick Start
- Basic Chat
- Chat Models
- OpenAI
- Anthropic
- Google (Gemini)
- Streaming
- Prompt Templates
- With Model Chain
- Output Parsers
- Structured Output
- Memory (Conversation History)
- RAG (Retrieval-Augmented Generation)
- Document Loading
npm install langchain @langchain/openai @langchain/core npm install @langchain/anthropic npm install @langchain/google-genai npm install @langchain/openai langchain npm install @langchain/langgraph
What does the langchain-js skill do?
Builds LLM-powered applications with LangChain.js for chat, agents, and RAG. Use when creating AI applications with chains, memory, tools, and retrieval-augmented generation in JavaScript.
How do I install it?
Run `npx skills add majiayu000/claude-skill-registry --skill langchain-js --agent claude-code` — it drops the skill into your project so the agent can pick it up. Swap the --agent value for codex, cursor or copilot if you use one of those.
Where does this skill come from?
From majiayu000/claude-skill-registry, a repository with 534 stars. We read it straight from the repository tree rather than a submitted listing, so what you see here is what is actually published.
Is a popular skill a good skill?
Not necessarily. Stars measure attention, not adoption — a repository can trend for a week and be abandoned. That is why we show the weekly change from our own snapshots next to the total, instead of a single flattering number.