context7

# Context7 Fetch current documentation for a library from [Context7](https://github.com/upstash/context7) (MIT, Upstash). The `ctx7` CLI and the `@upstash/context7-mcp` server read the same index. Use the CLI for a one-off lookup. Point an MCP client at the server when the agent should call the tools itself. ## When to use The task depends on the current API of a library, framework, SDK, or CLI: a signature, a config field, or a setup step. The query goes to Context7, so keep private code out of it. ## Install The CLI needs Node.js 22.13 or newer. The MCP package needs Node.js 20.18.1 or newer. ```sh node -v npx -y ctx7@latest --version npx -y @upstash/context7-mcp@latest --version ``` Checked on 2026-10-12: `ctx7` 0.6.0 and `@upstash/context7-mcp` 4.3.0. `@latest` moves. Stdio config for an MCP client. Calls without a key returned results. A key from the Context7 dashboard raises the rate limit. If the user already has one, pass it the way that client expects. Leave the key out of this file. ```json { "mcpServers": { "context7": { "command": "npx", "args": ["-y", "@upstash/context7-mcp@latest"] } } } ``` ## Commands Resolve a name, then query that id. `--json` prints output an agent can parse. ```sh npx -y ctx7@latest library react "useEffect cleanup" --json npx -y ctx7@latest docs /react/react "useEffect cleanup function" --json ``` `ctx7 docs` takes `--language` (for example `Python`) so examples in that language rank first. MCP tools, with the fields the 4.3.0 package publishes: 1. `resolve-library-id` with `libraryName` and `query`. 2. `query-docs` with `libraryId` from that result, a `query` about one topic, and optional `language`. Skip the resolve step only when the user already gave an id shaped like `/org/project` or `/org/project/version`. ## Gotchas - Several libraries can share a name. Prefer the id whose name matches, with more snippets and a higher reputation score. - Use the library's usual punctuation in `libraryName`, such as `Next.js`. - An old id can redirect. `/facebook/react` answered with a redirect to `/react/react`. Query the new id. - One topic per query. The MCP tool text says to stop after 3 calls to either tool on the same question. - A failed upstream call sets the tool error flag on `query-docs`. An empty "no documentation" result is a normal answer. - The query is sent to Context7. Leave out keys, passwords, and private code. - `ctx7 setup` and `ctx7 login` change agent config and can open a browser login. Run them only when the user asked to install Context7. --- Also on Honeypot — a free, open index of skills for AI agents: https://honeypot-e6c.pages.dev [](https://honeypot-e6c.pages.dev)