WebMCP Controller by Hamb_y
Let your own AI agent (Claude Code, Codex, Gemini CLI, opencode, any MCP client) read and drive this Firefox over MCP, with a live AI cursor showing what it's doing. Everything stays on your computer. Needs a small free companion helper app.
Extension Metadata
About this extension
WebMCP Controller connects the Firefox you already use (your tabs, logins and bookmarks) to an AI agent running on your own computer, through the Model Context Protocol (MCP).
What the agent can do:
• List, open, switch, move and close tabs and windows
• Read pages (accessibility snapshot, text, HTML, screenshots)
• Click, type, fill forms, scroll, press keys and wait for content
• Search bookmarks and history, list downloads, restore closed tabs
While it works, a glowing AI cursor glides to whatever it's clicking, with a small bubble saying what it's doing. You can turn it off in the popup.
How it works: Firefox add-ons can't open network ports, so the add-on starts a small companion helper app through Firefox native messaging. The helper serves MCP only on 127.0.0.1 (this computer), and every request needs a random secret token that the add-on generates. Nothing is sent to the developer or any third party. Your AI tool talks to the helper, and the helper talks to this add-on.
Setup (about a minute):
1. Install this add-on.
2. Click its toolbar icon. It shows a one-line command for your system that installs the helper app (Windows, macOS, Linux). Paste it into PowerShell or Terminal.
3. Click "Copy MCP config" and paste it into your AI tool.
Safety:
• Local only by default; token-protected
• Closing tabs or windows and deleting bookmarks need explicit confirmation
• No access to saved passwords; cookies are read-only
Source code for the add-on and the helper (MPL 2.0): https://github.com/hamb1y/webmcp-controller
What the agent can do:
• List, open, switch, move and close tabs and windows
• Read pages (accessibility snapshot, text, HTML, screenshots)
• Click, type, fill forms, scroll, press keys and wait for content
• Search bookmarks and history, list downloads, restore closed tabs
While it works, a glowing AI cursor glides to whatever it's clicking, with a small bubble saying what it's doing. You can turn it off in the popup.
How it works: Firefox add-ons can't open network ports, so the add-on starts a small companion helper app through Firefox native messaging. The helper serves MCP only on 127.0.0.1 (this computer), and every request needs a random secret token that the add-on generates. Nothing is sent to the developer or any third party. Your AI tool talks to the helper, and the helper talks to this add-on.
Setup (about a minute):
1. Install this add-on.
2. Click its toolbar icon. It shows a one-line command for your system that installs the helper app (Windows, macOS, Linux). Paste it into PowerShell or Terminal.
3. Click "Copy MCP config" and paste it into your AI tool.
Safety:
• Local only by default; token-protected
• Closing tabs or windows and deleting bookmarks need explicit confirmation
• No access to saved passwords; cookies are read-only
Source code for the add-on and the helper (MPL 2.0): https://github.com/hamb1y/webmcp-controller
Rated 0 by 0 reviewers
Permissions and data
Required permissions:
- Exchange messages with programs other than Firefox
- Read and modify bookmarks
- Download files and read and modify the browser’s download history
- Access browsing history
- Access recently closed tabs
- Access browser tabs
- Access your data for all web sites
Required data collection, according to the developer:
- Bookmarks
- Browsing activity
- Web site activity
- Web site content
Optional data collection, according to the developer:
- Technical and interaction data
More information
- Add-on Links
- Version
- 0.3.7
- Size
- 77.53 kB
- Last updated
- 9 days ago (4 Oct 2026)
- Related Categories
- Licence
- Mozilla Public Licence 2.0
- Privacy Policy
- Read the privacy policy for this add-on
- Version History
- Add to collection