Context7 indexes documentation for thousands of open-source libraries and serves it through MCP. The LLM client requests docs for a specific library version, Context7 returns the relevant slices, the agent gets accurate up-to-date API surface area without needing the model to be trained on the latest release. Solves the perennial LLM-hallucinates-an-API-that-does-not-exist problem for library code.
Pricing
Free · Hosted SaaS · Self-host option
Developer Consensus: Pros
Eliminates hallucinated APIs for any library Context7 indexes44× mentioned
Version-pinned doc retrieval — your agent uses your version37× mentioned
Coverage spans npm, PyPI, crates.io, RubyGems, plus most CNCF projects28× mentioned
Latency is sub-200ms for most requests — agents stay responsive19× mentioned
Common Friction Points
Niche or proprietary libraries are not indexed14× mentioned
Hosted version is free now but pricing model is TBD11× mentioned
Doc-fetch tokens count toward your LLM context budget9× mentioned
Self-host story exists but is more involved than the SaaS5× mentioned
Verified Peer Reviews
L
@lib_user_42
Senior Engineer · TypeScript · Mid
Verified
Stopped Cursor from inventing React APIs that do not exist.
Context7 is the missing piece for LLM-assisted coding against rapidly-evolving libraries. We pin to React 19, Context7 serves React 19 docs to Cursor, the suggestions stop hallucinating hooks that got renamed two majors ago.
O
@open_source_dev
Maintainer · Python · Solo
Verified
Coverage of PyPI is surprisingly good for an early product.
I maintain a 30k-star Python library. Context7 indexed it without me doing anything. Users tell me Claude actually answers questions about my library correctly now.
T
@token_budget
Platform Engineer · Mixed · Enterprise
Verified
Watch token usage. Doc dumps add up.
Context7 is great but each doc fetch is 500-2000 tokens depending on the topic. On a heavy day our agent uses 200k+ context just on doc retrieval. Plan for it.
Every review on this page is verified through GitHub OAuth and weighted by reviewer credibility, use-case match, and conflict-of-interest disclosure. Aggregate scores combine with recency decay so rankings reflect current reality.
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