langchainjs
LangChain.js - TypeScript framework for building LLM-powered applications with agents, chains, RAG, tools, memory, and integrations for OpenAI, Anthropic, Google, and hundreds of other providers
npx skills add majiayu000/claude-skill-registry --skill langchainjs-enuno-claude-command-and-c --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.
What it does
LangChain.js is a TypeScript framework for building applications powered by large language models. It provides standardized interfaces for connecting LLMs with diverse data sources, tools, and external systems through a modular architecture.
How it works
- It supports building AI agents with tool-calling capabilities and memory for conversations.
- Constructs chains of LLM operations and enables Retrieval Augmented Generation (RAG) with vector stores and retrievers.
- Defines Tools as functions that agents can call to interact with external systems; supports memory, and structured output via Zod or JSON Schema.
- Offers prompt templates, templates variables, and a variety of usage patterns including streaming responses.
- Demonstrates integration patterns for multiple providers and ecosystems, including LangGraph-based orchestration and LangSmith monitoring.
When to use it
- Building AI agents with tool-calling capabilities
- Creating chatbots with conversation memory
- Implementing Retrieval Augmented Generation (RAG) systems
- Connecting LLMs to external data sources and APIs
- Building chains of LLM operations
- Switching between AI providers without code changes
- Streaming LLM responses in real-time
- Implementing structured output from LLMs
- Creating document Q&A systems
- Building semantic search applications
What it can touch
- Tool definitions and usage are shown via code examples, including tools created with the language's tooling utilities.
- It demonstrates how to bind tools to models and how to use agents with those tools.
Caveats
- License is MIT as per frontmatter.
- Version 1.0.0 indicates initial release scope; no explicit risk notes beyond what's shown in examples.
# LangChain.js LangChain.js is a comprehensive TypeScript framework for building applications powered by large language models. It provides standardized interfaces for connecting LLMs with diverse data sources, tools, and external systems through a modular architecture. ## When to Use - Building AI agents with tool-calling capabilities - Creating chatbots with conversation memory - Implementing Retrieval Augmented Generation (RAG) systems - Connecting LLMs to external data sources and APIs - Building chains of LLM operations - Switching between AI providers without code changes - Streaming LLM responses in real-time - Implementing structured output from LLMs - Creating document Q&A systems - Building semantic search applications ## Core Concepts ### Agents Autonomous entities that use LLMs to decide which actions to take. Agents can call tools, access memory, and orchestrate complex workflows. ### Chains Sequences of operations that process inputs through multiple steps. Chains can combine prompts, LLM calls, and post-processing. ### Tools Functions that agents can call to interact with external systems (APIs, databases, web search, etc.). ### Memory Short-term and long-term contex
- When to Use
- Core Concepts
- Agents
- Chains
- Tools
- Memory
- Retrieval
- Messages
- Structured Output
- Installation
- Core Packages
- Provider Packages
- Package Structure
- Supported Environments
Install core packages npm install langchain @langchain/core Or with other package managers pnpm install langchain @langchain/core yarn add langchain @langchain/core bun add langchain @langchain/core OpenAI npm install @langchain/openai Anthropic npm install @langchain/anthropic
What does the langchainjs skill do?
LangChain.js - TypeScript framework for building LLM-powered applications with agents, chains, RAG, tools, memory, and integrations for OpenAI, Anthropic, Google, and hundreds of other providers
How do I install it?
Run `npx skills add majiayu000/claude-skill-registry --skill langchainjs-enuno-claude-command-and-c --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.