Developer Guide

Set up and run Context7 MCP locally for development

This guide covers how to set up the Context7 MCP server locally for development and testing.

Getting Started

Clone the project and install dependencies:

git clone https://github.com/upstash/context7.git
cd context7
pnpm i

Build:

pnpm run build

Run the server:

node packages/mcp/dist/index.js

CLI Arguments

context7-mcp accepts the following CLI flags:

Flag	Description	Default
--transport <stdio|http>	Transport to use. Use http for remote HTTP server or stdio for local integration.	stdio
--port <number>	Port to listen on when using http transport.	3000
--api-key <key>	API key for authentication (or set CONTEXT7_API_KEY env var).	-

Get your API key by creating an account at context7.com/dashboard.

Examples

HTTP transport on port 8080:

node packages/mcp/dist/index.js --transport http --port 8080

Stdio transport with API key:

node packages/mcp/dist/index.js --transport stdio --api-key YOUR_API_KEY

Environment Variables

You can use the CONTEXT7_API_KEY environment variable instead of passing the --api-key flag. This is useful for:

• Storing API keys securely in .env files
• Integration with MCP server setups that use dotenv
• Tools that prefer environment variable configuration

The --api-key CLI flag takes precedence over the environment variable when both are provided.

Using .env File

# .env
CONTEXT7_API_KEY=your_api_key_here
CONTEXT7_API_URL=https://context7.com/api

CONTEXT7_API_URL sets the base URL for Context7 API calls and defaults to https://context7.com/api. Override it for self-hosted deployments or proxies that sit in front of the API.

MCP Configuration with Environment Variable

{
  "mcpServers": {
    "context7": {
      "command": "npx",
      "args": ["-y", "@upstash/context7-mcp"],
      "env": {
        "CONTEXT7_API_KEY": "YOUR_API_KEY"
      }
    }
  }
}

MCP Tools

The server registers two tools. Both are read-only, idempotent, and open-world (annotations: readOnlyHint, idempotentHint, and openWorldHint are true; destructiveHint is false).

resolve-library-id

Resolves a package/product name to a Context7-compatible library ID and returns matching libraries. Call this before query-docs unless the user already provides a library ID in /org/project or /org/project/version format.

Parameter	Type	Required	Description
libraryName	string	yes	Library name to search for and resolve to a Context7-compatible library ID. Use the official name with proper punctuation (e.g., “Next.js” not “nextjs”).
query	string	yes	What to look up in the library’s documentation, used to rank results by relevance. Sent to the Context7 API; do not include sensitive or confidential information.

query-docs

Retrieves and queries up-to-date documentation and code examples for a library. Requires a valid library ID from resolve-library-id (or one provided directly by the user).

Parameter	Type	Required	Description
libraryId	string	yes	Exact Context7-compatible library ID (e.g., /vercel/next.js or /vercel/next.js/v14.3.0-canary.87).
query	string	yes	What to look up, scoped to a single concept. Make a separate call per concept unless the question is about how concepts interact. Do not include sensitive or confidential information.

The server declares the prompts and resources capabilities but registers no prompts and no resources — prompts/list and resources/list answer with empty collections.

Local Development Configuration

When developing locally, use this configuration to run from source:

{
  "mcpServers": {
    "context7": {
      "command": "npx",
      "args": ["tsx", "/path/to/folder/context7/packages/mcp/src/index.ts", "--api-key", "YOUR_API_KEY"]
    }
  }
}

Testing with MCP Inspector

Test your setup using the MCP Inspector:

npx -y @modelcontextprotocol/inspector npx @upstash/context7-mcp

This opens an interactive inspector to verify Context7 tools are working correctly.