Browser Control MCP

An MCP server paired with a browser extension that enables LLM clients, such as Claude Desktop, to control the user’s local browser (Firefox).

Features

The MCP server supports the following tools:

• Open or close tabs
• Get the list of opened tabs
• Reorder opened tabs
• Read and search the browser’s history
• Read webpages text content and links
• Find and highlight text in a browser tab

In addition, the contents of each opened tab in the browser is available as an MCP resource, allowing the user to select browser tabs in the MCP client itself (e.g. Claude) and load their content into the context.

Example use-cases:

Tab management

• “Close all non-work related tabs in my browser.”
• “Rearrange tabs in my browser in an order that makes sense.”
• “Close all tabs in my browser that haven’t been accessed within the past 24 hours”

Browser history search

• “Help me find an article in my browser history about the Milford track in NZ.”
• “Open all the articles about AI that I visited during the last week, up to 10 articles, avoid duplications.”

Browsing and research

• “Open hackernews in my browser, then open the top story, read it, also read the comments. Do the comments agree with the story?”
• “In my browser, use Google Scholar to search for papers about L-theanine in the last 3 years. Open the 3 most cited papers. Read them and summarize them for me.”
• “Use google search in my browser to look for flower shops. Open the 10 most relevant results. Show me a table of each flower shop with location and opening hours.”

Installation

Clone this repository, then run the following commands in the main repository directory to build both the MCP server and the browser extension.

npm install
npm install --prefix mcp-server
npm install --prefix firefox-extension
npm run build

The final npm run build command will also generate a shared secret between the MCP server and the extension.

Usage with Claude Desktop:

Add the following configuration to claude_desktop_config.json (use the Edit Config button in Claude Desktop Developer settings):

{
    "mcpServers": {
        "browser-control": {
            "command": "node",
            "args": [
                "<path to repo>/mcp-server/dist/server.js"
            ]
        }
    }
}

Replace <path to repo> with the correct path.

Make sure to restart Claude Desktop.

Usage with Firefox

The browser-control-mcp extension was developed for Firefox.

To install the extension:

1. Type about:debugging in the Firefox URL bar
2. Click on “This Firefox”
3. click on “Load Temporary Add-on…”
4. Select the manifest.json file under the firefox-extension folder in this project

If you prefer not to run the extension on your personal Firefox browser, an alternative is to download a separate Firefox instance (such as Firefox Developer Edition, available at https://www.mozilla.org/en-US/firefox/developer/).