Context7

Context7 — Version-Specific Library Documentation

Fetches up-to-date, version-specific documentation and code examples from 800+ libraries directly into Claude's context. Eliminates hallucination from training data cutoffs.

When to Use This Skill

• Current API docs: "How do I do X in Next.js 15?" — gets real docs, not cached training data
• Version-specific patterns: Supabase, React, LangChain, etc. APIs that change between versions
• Anti-hallucination: When Claude generates code for external libraries that may have changed
• User triggers: "use context7", "check docs for X", "use library /nextjs/nextjs", "get current API for Y"

When Not to Use

• For internal codebase understanding — use codebase-memory
• For arbitrary web pages — use gemini-url-context or web-summary
• For research synthesis — use notebooklm or perplexity-research

Setup

# Get your API key (free tier available)
npx ctx7 setup

# Or add CONTEXT7_API_KEY to your .env
export CONTEXT7_API_KEY=your_key_here

No key required for basic public library queries. Key unlocks higher rate limits and private libraries.

MCP Tools (2)

Usage Patterns

Pattern 1: Natural language trigger

User: "How do I set up middleware in Next.js 15? Use context7."
Claude calls: resolve-library-id("next.js") → /nextjs/nextjs
Claude calls: query-docs("/nextjs/nextjs", "middleware configuration Next.js 15")
Claude returns: Current, accurate code with Next.js 15 syntax

Pattern 2: Direct library ID

User: "Show me how to use Supabase Row Level Security. Library: /supabase/supabase"
Claude calls: query-docs("/supabase/supabase", "row level security RLS policies")

Pattern 3: Integrated in code generation

When writing code that uses an external library, proactively call context7 for the key APIs to ensure the generated code matches the current version.

Supported Libraries (800+)

Covers: Next.js, React, Supabase, LangChain, Vercel, Tailwind, Prisma, Drizzle, Astro, SvelteKit, Nuxt, Vue, Angular, Express, Fastify, tRPC, Zod, shadcn/ui, Radix UI, Framer Motion, PyTorch, TensorFlow, Pandas, FastAPI, Django, Flask, SQLAlchemy, and hundreds more.

Full list: https://context7.com/libraries

Configuration in MCP Settings

{
  "context7": {
    "command": "npx",
    "args": ["-y", "@upstash/context7-mcp@4.0.7"],
    "env": {
      "CONTEXT7_API_KEY": "<your_key>"
    }
  }
}

Integration with Other Skills

Attribution

Context7 by Upstash. https://github.com/upstash/context7