Context7 MCP
51K stars. Solves the #1 Claude coding problem: hallucinated API calls from outdated training data. Grounds responses in real, current documentation.
Pulls current, version-specific library documentation and code examples straight from the source into Claude's context, eliminating hallucinated or outdated APIs. Works in two modes: a ctx7 CLI + skill (no MCP required) or an MCP server exposing resolve-library-id and query-docs tools. Free to use; a free API key from context7.com raises rate limits.
- Get accurate, up-to-date coding docs instead of outdated guesses
- Look up the correct way to use any software library instantly
- Avoid errors caused by Claude suggesting features that no longer exist
51K stars. Solves the #1 Claude coding problem: hallucinated API calls from outdated training data. Grounds responses in real, current documentation.
Any developer using Claude for coding. Especially valuable when working with fast-changing libraries (React, Next.js, etc.).
https://github.com/upstash/context7
By Upstash
How to Get It
npx ctx7 setup
Tip: Paste this into a Claude Code conversation. Verify command matches your Claude Code version.
Once it’s connected, paste this into Claude:
Help me get accurate, up-to-date coding docs instead of outdated guesses
Trust Signals Reviewed
Data & Access
Community Pulse Growing
Discussed on Hacker News, Reddit
- Context7 MCP Server: Up-to-date documentation for LLMs and AI code editors — Hacker News · 3 pts
1 mentions across 1 sources
Reviewer notes
Reviewed review. These are observations, not a security certification.
2.4M monthly downloads — among most downloaded MCP servers in ecosystem. v2.1.6, actively maintained. No API key required for basic use. Completely universal — any developer using any library benefits. Low setup friction. Main risk is external service dependency on Context7's hosted service.
Read-only access to public documentation — extremely low permission surface. No credentials required beyond optional API token. Dependencies: undici (HTTP), jose (JWT). Upstash is mid-size cloud vendor with good track record.
2026-04-02: LIMITATION: Coverage depends on which libraries Context7 has indexed — obscure or private packages return nothing. Rate-limited without an API key.
Things to check
- Requires MCP-compatible Claude interface; free tier has rate limits unless API key provided. Coverage depends on whether libraries are indexed in Upstash's documentation database.
How to evaluate tools before deploying →
Data shown here comes from public APIs and automated scanning. Reviewer notes reflect one person's experience. This is not a security certification or legal recommendation. Always evaluate tools according to your own organization's policies.
Evaluation
2.4M monthly downloads — among most downloaded MCP servers in ecosystem. v2.1.6, actively maintained. No API key required for basic use. Completely universal — any developer using any library benefits. Low setup friction. Main risk is external service dependency on Context7's hosted service.