Context7
Context7 fixes a narrow but common annoyance: AI coding assistants quoting last year's API for a fast-moving library. It is quick to wire into Cursor, Claude Code and similar tools, and the free tier is enough for an individual developer. It only helps for libraries that are indexed and documented well, and it adds prompt tokens on every lookup.
Pros
- Version-specific docs pulled from source rather than model training data
- Works over MCP or via a CLI and skill, with one-command setup
- Free tier plus a $10 per-seat Pro plan
- Open-source code under MIT, built by Upstash
Cons
- Free plan stops at 1,000 calls a month, with a small daily bonus allowance after that
- Quality depends on how well each library's docs are indexed and ranked
- Retrieved snippets consume context window space on every call