Context7 for Cursor and Claude Code: setup and verification

When an agent suggests an unfamiliar library method, ask where it came from. A plausible example may belong to another package version or not match the API at all. Verification requires documentation for the library your project actually uses.

Context7 finds library documentation and supplies relevant passages to an agent. It connects to Cursor and Claude Code. It provides sources for API work; you still need to verify the resulting code in your application. Context7 overview.

• Context7 overview

This guide covers local clients and a control request that distinguishes an actual documentation lookup from an answer based on memory. Instructions were checked against official materials; no connection to your account or practical account test was performed.

When Context7 helps

Choose a library-dependent task: router configuration, form handling, an ORM query or SDK file upload. You need to know which methods exist, their inputs and documented behavior.

For a typo or your own business logic, external library search may add nothing. Identify the missing knowledge first.

Do not ask to “connect all documentation.” Ask a specific question the source should answer.

How documentation lookup works

The MCP connection has two main tools: `resolve-library-id` finds the library identifier, and `query-docs` retrieves material for a question. Skip resolution when the identifier is already known. Integration documentation.

• Integration documentation

Task and package version
        ↓
Choose the correct library
        ↓
Find an answer in documentation
        ↓
Compare with project code
        ↓
Make and verify the change

Check each transition independently. Rewriting an example neatly does not fix choosing the wrong library. Relevant documentation does not prove correct integration into your application.

Prepare before installation

You need Cursor or Claude Code, internet access and working Node.js with npm/npx for setup. The ctx7 installer requires Node.js 18 or newer; use a supported LTS release for a new environment. CLI requirements.

• CLI requirements

In a normal terminal:

node --version
npx --version

If either command is missing, configure Node.js in the environment that will run setup. Check the actual macOS, Windows or WSL terminal you use.

If Context7 is already connected, inspect its configuration before reinstalling. Duplicate entries with different authentication methods make it harder to tell which connection the agent uses.

Connect Claude Code

Run in a terminal:

npx ctx7 setup --claude

The installer guides OAuth sign-in and connection selection. Follow its prompts and complete browser authorization. This is the documented starting path for Claude Code.

• Claude Code

Two modes are available: MCP and CLI + Skills. MCP exposes server tools; CLI + Skills uses ctx7 commands guided by a skill. Choose MCP for the control request below so you can inspect named tool calls. CLI setup is global by default; `--project` scopes it to the current project. Setup modes.

• Setup modes

Afterward, open Claude Code and run `/mcp` to inspect available servers and their status. MCP management.

• MCP management

If you chose CLI + Skills, look for actual ctx7 commands instead of an MCP server. These are different routes to documentation.

Connect Cursor

Use its separate terminal command:

npx ctx7 setup --cursor

Complete authorization and choose MCP to reproduce this guide's control request. Cursor instructions.

• Cursor instructions

For manual setup, open Cursor's MCP settings. Global configuration is `~/.cursor/mcp.json`; project configuration is `.cursor/mcp.json`. Context7 documents this HTTP configuration:

{
  "mcpServers": {
    "context7": {
      "url": "https://mcp.context7.com/mcp",
      "headers": {
        "Authorization": "Bearer YOUR_API_KEY"
      }
    }
  }
}

`YOUR_API_KEY` is a placeholder for your account's key. This matches the official client configuration. In an existing file, add context7 inside mcpServers while preserving other connections.

• official client configuration

Do not commit a personal key to a shared repository. A personal configuration file is easier for the first manual setup. OAuth uses a different endpoint, `https://mcp.context7.com/mcp/oauth`; do not mix authentication methods. Authentication options.

• Authentication options

Automatic setup is usually sufficient. Use manual configuration when you need to inspect or manage it yourself.

Verify actual Context7 use

Start with a familiar library so a wrong source is easier to spot. In a project using Zod, ask:

Find the installed Zod version. Use Context7 to determine how that version validates email and returns validation results without throwing. Resolve the library first, then query documentation. Show the identifier, source links and a short example. If the documentation cannot confirm the version, say so. Do not modify files.

This is a learning prompt, not a recorded service result. If Zod is absent, choose a familiar installed package and a small API question.

Check three levels:

If you supplied the identifier, missing `resolve-library-id` is fine. What matters is querying the correct library. An eloquent answer after a tool error does not turn a failed lookup into verification.

Why the library version matters

Mentioning a version narrows the request, but you still need to match it to the returned material. Context7 CLI offers versioned identifiers when search results contain them; select from the actual returned list. Libraries and versions.

• Libraries and versions

If your project uses an older major version and the example targets a newer one, do not immediately migrate everything to fit it. First find whether the installed version supports the operation. A dependency upgrade is a separate decision with broader effects.

Use this sequence:

1. Identify the installed version from project files.
2. Find the documented operation.
3. Check the example's compatibility.
4. Make a limited change and run a relevant check.

If you cannot confirm the version, open the release's official documentation or migration guide directly. One tool returning nothing does not mean the library has no solution.

Must you always write “use context7”?

An explicit `use context7` helps test the connection. Automatic setup may also install a documentation skill. Invocation options.

• Invocation options

For ongoing work, define when to use it:

When a solution depends on an external library API, first identify
the installed version and find suitable documentation through Context7.
If the source is unavailable or its version unconfirmed, report that
and check the official documentation directly.

This is a suggested rule. Put it in CLAUDE.md or Cursor project rules. It defines a trigger and fallback without demanding external searches for every wording change.

• CLAUDE.md

If Context7 does not work

Inspect the stage that failed. Reinstalling the whole client rarely explains the cause.

The first four concern access; the last two concern lookup and application. Consult Troubleshooting for technical details.

• Troubleshooting

Cursor Cloud Agents use a separate MCP configuration. A working local setup does not prove availability in a cloud run. Follow the Cloud Agents instructions.

• Cloud Agents instructions