Lighthouse MCP server

Lighthouse MCP Server is a specialized server that wraps around Google's Lighthouse tool, allowing you to measure various performance metrics for web pages through the Model Context Protocol (MCP). It enables running comprehensive audits on any URL to get performance scores and metrics with configurable device emulation and network settings.

Installation Options

Using npx (Recommended)

Run the tool directly without installation:

npx lighthouse-mcp

Global Installation

Install the package globally:

npm install -g lighthouse-mcp

Then run it:

lighthouse-mcp

MCP Configuration

Configuration with npm Installation

Add the following to your MCP settings configuration file:

{
  "mcpServers": {
    "lighthouse": {
      "command": "npx",
      "args": ["lighthouse-mcp"],
      "disabled": false,
      "autoApprove": []
    }
  }
}

Available Tools

run_audit

Run a comprehensive Lighthouse audit on a URL.

Parameters:

• url (required): The URL to audit
• categories (optional): Array of categories to audit (defaults to all)
  • Options: "performance", "accessibility", "best-practices", "seo", "pwa"
• device (optional): Device to emulate (defaults to "mobile")
  • Options: "mobile", "desktop"
• throttling (optional): Whether to apply network throttling (defaults to true)

Example:

{
  "url": "https://example.com",
  "categories": ["performance", "accessibility"],
  "device": "desktop",
  "throttling": false
}

get_performance_score

Get just the performance score for a URL.

Parameters:

• url (required): The URL to audit
• device (optional): Device to emulate (defaults to "mobile")
  • Options: "mobile", "desktop"

Example:

{
  "url": "https://example.com",
  "device": "mobile"
}

Example Usage

Once the MCP server is configured, you can use it with Claude by asking questions like:

What's the performance score for example.com?

Claude will use the get_performance_score tool to analyze the website and return the results.

Requirements

• Node.js 16+
• Chrome/Chromium browser (for Lighthouse)

How to add this MCP server to Cursor

There are two ways to add an MCP server to Cursor. The most common way is to add the server globally in the ~/.cursor/mcp.json file so that it is available in all of your projects.

If you only need the server in a single project, you can add it to the project instead by creating or adding it to the .cursor/mcp.json file.

Adding an MCP server to Cursor globally

To add a global MCP server go to Cursor Settings > MCP and click "Add new global MCP server".

When you click that button the ~/.cursor/mcp.json file will be opened and you can add your server like this:

{
    "mcpServers": {
        "cursor-rules-mcp": {
            "command": "npx",
            "args": [
                "-y",
                "cursor-rules-mcp"
            ]
        }
    }
}

Adding an MCP server to a project

To add an MCP server to a project you can create a new .cursor/mcp.json file or add it to the existing one. This will look exactly the same as the global MCP server example above.

How to use the MCP server

Once the server is installed, you might need to head back to Settings > MCP and click the refresh button.

The Cursor agent will then be able to see the available tools the added MCP server has available and will call them when it needs to.

You can also explictly ask the agent to use the tool by mentioning the tool name and describing what the function does.