GitHub - smankoo/open-browser-control: Give AI agents control of your Chrome browser. Works with any MCP client.

4 min read Original article ↗

Give AI agents control of your browser — Chrome or Firefox. Works with Kiro, Claude Code, Claude Desktop, Cursor, and any MCP client.

The AI uses your real browser — your cookies, sessions, and logins. When it hits something it can't handle (sign-in, CAPTCHA, MFA), it asks you to step in, then continues where it left off.

Install either the Chrome or the Firefox extension — the MCP server speaks the same protocol to both.

Quick Start

Step 1: Add MCP config

Add to your MCP client's config:

Kiro — add to .kiro/settings/mcp.json (workspace) or ~/.kiro/settings/mcp.json (global):

{
  "mcpServers": {
    "browser": {
      "command": "npx",
      "args": ["-y", "open-browser-control"]
    }
  }
}
Claude Code
claude mcp add browser -- npx -y open-browser-control
Claude Desktop / Cursor / other MCP clients

Add to your MCP config file:

{
  "mcpServers": {
    "browser": {
      "command": "npx",
      "args": ["-y", "open-browser-control"]
    }
  }
}

Step 2: Install the browser extension

Pick whichever browser you'd like the AI to drive.

Chrome — install from the Chrome Web Store:

Open Browser Control on the Chrome Web Store

Firefox

Unpack the extension and load it in Firefox:

npx -y open-browser-control --extension firefox

This prints a path like ~/open-browser-control-extension-firefox. Then:

  1. Open about:debugging#/runtime/this-firefox
  2. Click Load Temporary Add-on…
  3. Pick the manifest.json inside that folder

Firefox clears unsigned temporary add-ons on restart. For a permanent install, use Firefox Developer Edition (xpinstall.signatures.required=false) or sign the extension via AMO.

Chrome — load unpacked

The extension is auto-installed to ~/open-browser-control-extension/ on first run. Load it in Chrome:

  1. Open chrome://extensions/
  2. Enable Developer mode (toggle in top right)
  3. Click Load unpacked
  4. Select the folder: ~/open-browser-control-extension/

Done. The extension auto-connects when your agent starts. No servers to run, no buttons to click.


How It Works

AI Agent          MCP Server              Browser Extension
(Kiro,       ◄──► (npx open-browser-  ◄──► (Chrome: CDP, or
 Claude, ..)      control)                  Firefox: scripting API)
              stdio    ws://localhost:9334    auto-connect
  1. Your agent starts the MCP server automatically (from the config above)
  2. MCP server starts a WebSocket bridge on localhost:9334
  3. The browser extension (Chrome or Firefox) auto-connects (polls every 2s until it finds the bridge)
  4. Agent sends tool calls → extension executes (via Chrome DevTools Protocol on Chrome, or the WebExtensions scripting API on Firefox) → results flow back

Both extensions implement the same JSON protocol over WebSocket, so the MCP server, bridge, and agents never need to know which browser is on the other end.


User/AI Handoff

Mode What happens
Collaborative (default) Both user and AI interact with the page
AI Control AI drives, user watches
User Control AI paused, user takes over
AI browsing → hits login page → calls browser_request_user("Please sign in")
  → user signs in → clicks "Done" in side panel → AI continues, now authenticated

Browser Tools

19 tools available to the AI:

Tool What it does
browser_navigate Go to a URL
browser_get_dom Get interactive elements with positions and text (primary way to read pages)
browser_get_page_info URL, title, dimensions, scroll position
browser_execute_js Run JavaScript in page context
browser_click Click by selector, text, or coordinates
browser_type Type text, optionally clear first or press Enter
browser_scroll Scroll up/down/left/right
browser_keypress Press any key with modifiers
browser_hover Hover over an element
browser_select_option Pick from a dropdown
browser_wait Wait for element, text, or fixed time
browser_screenshot Capture page as PNG (use sparingly — DOM tools are faster)
browser_request_user Ask user to take over (sign in, CAPTCHA, etc.)
browser_new_tab_group Create a named tab group for a task
browser_new_tab Open a new tab in the current group
browser_close_tab Close a tab
browser_switch_tab Switch to a tab by ID
browser_list_tabs List all open tabs in this session
browser_set_session_name Set the session name (shown on tab group)

Standalone Use (no MCP)

If you're not using an MCP client:

npx -y open-browser-control --bridge    # starts WebSocket bridge only

Connect your agent to ws://localhost:9334 and send JSON messages:

{"type": "action", "action": "navigate", "id": "1", "params": {"url": "https://example.com"}}
{"type": "action", "action": "click", "id": "2", "params": {"text": "Sign In"}}
{"type": "action", "action": "get_dom", "id": "3"}

CLI

npx -y open-browser-control                 # Start MCP server (default)
npx -y open-browser-control --bridge        # Standalone WebSocket bridge
npx -y open-browser-control --extension     # Print extension install path
npx -y open-browser-control --port 9000     # Custom port
npx -y open-browser-control --help          # Help

Development

git clone https://github.com/smankoo/open-browser-control
cd open-browser-control
npm install
npm run build    # builds both browsers → dist/chrome, dist/firefox
                 # and packages to extension/ and extension-firefox/
npm run dev      # watch mode
npm start        # run MCP server locally

Requirements

  • Chrome 116+ or Firefox 128+
  • Node.js 18+