BrowserLemon 🍋

An open-source browser bridge that lets AI control your local Chrome's current logged-in session via MCP. It focuses on social media draft creation and publish flows after user approval.

Early MVP: Do not publish to production accounts without direct review. Element refs may become invalid as site UIs change.

Features

• MCP standard input/output (stdio) server

• Uses already-logged-in Chrome tabs: cookies and passwords are never copied to the MCP server

• Page summary, tab list, navigation, click, input

• draft_social_post and publish_social_post which requires explicit confirmed=true

• Localhost-only WebSocket and publish domain allowlist

• MIT license

Related MCP server: Tabryn

Installation

npm install
npm run build

In Chrome, go to chrome://extensions → Developer mode → Load unpacked → select the extension folder in this repository.

MCP client configuration example:

{
  "mcpServers": {
    "browserlemon": {
      "command": "node",
      "args": ["/absolute/path/to/browserlemon/dist/index.js"]
    }
  }
}

After restarting the MCP client, click the BrowserLemon icon in the Chrome toolbar. When the badge shows ON, you are connected.

Recommended Workflow

1. Check the connection with browser_status

2. Use list_tabs and read_page to confirm the target and composer ref

3. Enter text with draft_social_post

4. The user reviews the content in the browser

5. Only call publish_social_post(confirmed=true) when the user has explicitly approved

Security Model

The extension runs with the user's browser permissions, so it is powerful. Run the server only from a trusted local MCP client. The bridge binds only to 127.0.0.1, and password input values are excluded from page snapshots. However, page bodies may contain personal information, so you should also review the data policy of the AI service you connect to.

Supported publish domains: X/Twitter, LinkedIn, Facebook, Instagram, Threads, Bluesky, Mastodon.social. Reading and draft input work on general http(s) pages as well.

Contributing

Bug reports and PRs are welcome. Next priorities are per-site adapters, image upload, scheduled publishing, audit logs, and finer-grained extension permissions.