Magnitude MCP

A Model Context Protocol (MCP) server that gives agents the ability to interact with a browser using the Magnitude framework.

Requirements

Since Magnitude relies on vision-based browser interaction, the agent using this MCP must be visually grounded. Generally this means Claude (Sonnet 3.7/4, Opus 4) or Qwen VL series. See docs for more info.

Capabilities

Magnitude MCP enables the same browser actions as the Magnitude agent but for any MCP-compatible agent instead:

• 🖥️ Open a browser with a persistent profile
• 🖱️ Click, type, drag, etc. using pixel-based coordinates
• 👁️ Automatically see screenshot after each interaction
• ⚡ Take multiple actions at once for efficiency

Installation

npm i -g magnitude-mcp@latest

MCP Configuration:

{
  "mcpServers": {
    "magnitude": {
      "command": "npx",
      "args": [
        "magnitude-mcp"
      ]
    }
  }
}

Claude Code Setup

claude mcp add magnitude -- npx magnitude-mcp

Cline Setup

Go to MCP Servers -> Marketplace, search for Magnitude, click Install

Cursor Setup

1. Open Cursor Settings
2. Go to Features > MCP Servers
3. Click "+ Add new global MCP server"
4. Enter the following code:

{
  "mcpServers": {
    "magnitude": {
      "command": "npx",
      "args": [
        "magnitude-mcp"
      ]
    }
  }
}

Windsurf Setup

Add this to your ./codeium/windsurf/model_config.json:

{
  "mcpServers": {
    "magnitude": {
      "command": "npx",
      "args": [
        "magnitude-mcp"
      ]
    }
  }
}

Configuration Options

The MCP can optionally be configured with a different persistent profile directory (for example if you want different projects to use their own browser cookies and local storage), to use stealth mode, or to change the default viewport dimensions.

{
  "mcpServers": {
    "magnitude": {
      "command": "npx",
      "args": [
        "magnitude-mcp"
      ],
      "env": {
        "MAGNITUDE_MCP_PROFILE_DIR": "/Users/myuser/.magnitude/profiles/default", 
        "MAGNITUDE_MCP_STEALTH": "true", 
        "MAGNITUDE_MCP_VIEWPORT_WIDTH": "1024",
        "MAGNITUDE_MCP_VIEWPORT_HEIGHT": "728"
      }
    }
  }
}

• MAGNITUDE_MCP_PROFILE_DIR: Stores cookies and local storage so that credentials can be re-used across agents using the MCP (default: ~/.magnitude/profiles/default)
• MAGNITUDE_MCP_STEALTH: Add extra stealth settings to help with anti-bot detection (default: disabled)
• MAGNITUDE_MCP_VIEWPORT_WIDTH: Override viewport width (default: 1024)
• MAGNITUDE_MCP_VIEWPORT_WIDTH: Override viewport width (default: 728)

Examples

Why connect your agent to a browser?

• Enable coding agents to see and interact with web apps as they build
• Interact with sites that don't have APIs
• Browse documentation that isn't accessible with fetch
• Improvised testing
• Or whatever else you find use for!

It's even suitable for non-engineering tasks if you just want an easily accessible browser agent.

Troubleshooting

If the agent model is not Claude Sonnet 4, Sonnet 3.7, Opus 4, Qwen 2.5 VL, or Qwen 3 VL, it will probably not work with this MCP - because the vast majority of models cannot click accurately based on an image alone.