sh6drack/zen-mcp

The first MCP server for **Zen Browser**. Automate Zen from Claude Code, Cursor, or any MCP client.
No Selenium. No Playwright. No browser drivers. Just WebSocket.
Setup (2 minutes)
1. Start Zen with remote debugging
> **Pro tip**: Add alias zen='open /Applications/Zen.app --args --remote-debugging-port 9222' to your shell config. Then just run zen.
2. Add to Claude Code
Add to ~/.claude/mcp_servers.json:
> If you cloned instead of npm install, use "command": "node", "args": ["/absolute/path/to/zen-mcp/server.mjs"]
Add to ~/.claude/settings.json:
**That's it.** Start a new Claude Code session and the zen_* tools are available.
20 Tools
Browse
| Tool | What it does |
|------|-------------|
| zen_navigate | Go to a URL |
| zen_list_pages | List all open tabs |
| zen_select_page | Switch to a tab |
| zen_new_tab | Open a new tab |
| zen_close_tab | Close a tab |
See
| Tool | What it does |
|------|-------------|
| zen_snapshot | Page structure with selectors (filter: all/interactive/form) |
| zen_screenshot | Capture a screenshot |
| zen_get_page_text | Get page title, URL, and text |
| zen_get_form_fields | List all form fields with labels and values |
Interact
| Tool | What it does |
|------|-------------|
| zen_click | Click an element |
| zen_fill | Type into an input or textarea |
| zen_select_option | Pick a dropdown option |
| zen_check | Toggle a checkbox or radio |
| zen_press_key | Keyboard input (Enter, Tab, Ctrl+A, etc.) |
| zen_fill_form | Fill multiple fields at once |
| zen_scroll | Scroll the page or to an element |
Utility
| Tool | What it does |
|------|-------------|
| zen_evaluate | Run JavaScript in the page |
| zen_wait | Wait N milliseconds |
| zen_wait_for | Wait for text or element to appear |
| zen_reconnect | Force reconnect to Zen |
How It Works
zen-mcp speaks **WebDriver BiDi** (W3C standard) directly over WebSocket. Form filling uses native value setters with input/change event dispatch so React, Vue, and Angular apps work correctly.
What Works Well
- **Navigation, clicking, form filling** — rock solid, handles React/Vue/Angular
- **Screenshots and page reads** — reliable content extraction
- **Tab management** — open, close, switch between tabs
- **JavaScript evaluation** — run any code in the page context
- **Keyboard input** — shortcuts, Enter, Tab, modifier combos
Known Limitations
- Zen inherits Firefox's WebDriver BiDi implementation, which is still maturing. Some advanced BiDi commands that work in Chrome may not be available yet.
- Zombie sessions can only be cleared by restarting Zen (BiDi session.end is connection-scoped). zen-mcp detects this and tells you what to do.