Context7
by Upstash
Pipes up-to-date, version-specific library documentation straight into an agent's context, so generated code matches the API that actually exists instead of a model's stale training data.
Add to Claude Code
claude mcp add context7 -- npx -y @upstash/context7-mcp
About
Context7 fetches current, version-matched documentation and code examples for a library at prompt time, ending the pattern where a model trained on an older API version confidently generates code that no longer exists.
It works via two tools: one resolves a library name to a Context7-specific ID, and the other pulls the relevant documentation for your question — in practice, most people just add "use context7" to a prompt and let the agent orchestrate both calls.
Key features
- Version-matched documentation instead of stale training data
- Covers thousands of popular libraries and frameworks
- Community-extendable — submit any missing project
- Free tier available, API key recommended for higher rate limits
Use cases
- Generate code against the current version of a fast-moving framework like Next.js
- Avoid hallucinated methods when working with a library the model was never trained on
- Pull accurate usage examples for a less-common package
Available tools
resolve-library-id
Turns a library name (e.g. "supabase") into a Context7-specific documentation ID.
get-library-docs
Fetches version-matched documentation and examples for a resolved library ID.
Frequently asked questions
Do I need an API key?
A free key from context7.com/dashboard raises your rate limit, but the server works without one at a lower limit.
How do I actually use it in a prompt?
Append "use context7" to a prompt that involves a specific library, and the agent resolves the library ID and pulls its docs automatically.