Tabryn

The Browser Runtime for AI Agents

Your browser. Your session. Any agent.

npm version license node typescript vitest

Installation • Features • Architecture • Tools • CLI • Contributing

Tabryn connects AI coding agents to the Chrome browser you're already using — existing tabs, existing sessions, real application state — through a universal MCP browser runtime.

Why Tabryn?

Browser automation traditionally means running a separate browser or profile. Coding agents need controlled access to the real development browser — the one with your logged-in sessions, your localhost tabs, your actual application state. Tabryn bridges this gap.

Features

Feature	Description
Real Browser State	Access your actual Chrome tabs, sessions, and cookies
MCP Native	First-class Model Context Protocol support
Zero Config	Works out of the box with your existing Chrome
Secure by Design	Local-only communication, no credential exposure
Multi-Agent	Works with Claude Code, Codex, Kiro, OpenCode, Gemini CLI, and more

Installation

# Clone and build
git clone https://github.com/idugeni/tabryn.git
cd tabryn
npm install
npm run build

# Set up native messaging host
node dist/cli/index.js install

Load Chrome Extension

Open chrome://extensions
Enable Developer mode
Click Load unpacked
Select the extension/ directory

That's it! Extension will auto-configure on first connection.

Add to MCP Client

claude mcp add tabryn -- node /path/to/tabryn/dist/mcp/index.js

Add to .vscode/mcp.json:

{
  "servers": {
    "tabryn": {
      "command": "node",
      "args": ["/path/to/tabryn/dist/mcp/index.js"]
    }
  }
}

Add to your MCP config:

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

Verify

node dist/cli/index.js doctor

Architecture

┌─────────────┐     ┌─────────────┐     ┌─────────────┐     ┌─────────────┐
│  AI Agent   │────▶│  MCP Server │────▶│    Bridge   │────▶│   Chrome    │
│             │◀────│             │◀────│             │◀────│  Extension  │
└─────────────┘     └─────────────┘     └─────────────┘     └─────────────┘
     stdio               TCP            Native Messaging      DevTools API

Supported Agents:

Claude Code ─┐
Codex CLI ───┤
Kiro ────────┤
OpenCode ────┤
OpenClaw ────┼──→ Tabryn ──→ Your Chrome
Hermes ──────┤
Gemini CLI ──┤
Custom Agent ┘

Available Tools

Tool	Description
`list_tabs`	List all open Chrome tabs
`select_tab`	Activate a specific tab
`create_tab`	Open a new tab
`close_tab`	Close a tab
`navigate`	Navigate to URL or go back/forward
`read_page`	Read page accessibility tree
`screenshot`	Capture tab screenshot
`click`	Click at coordinates
`type`	Type text into focused element
`scroll`	Scroll the page
`form_input`	Set form element values
`execute_js`	Execute JavaScript in page context
`read_console`	Read console messages
`read_network`	Read network requests
`reload`	Reload the page
`wait`	Wait for page condition

Example: Development Workflow

┌──────────────────────────────────────────────────────────────────────────┐
│  Agent: Edit code → Run dev server → list_tabs → find localhost tab     │
│  Agent: screenshot → inspect UI → read_console → find errors            │
│  Agent: click → interact → reload → verify fix                          │
└──────────────────────────────────────────────────────────────────────────┘

CLI Commands

Command	Description
`tabryn install`	Set up native messaging host and extension
`tabryn mcp`	Start the MCP server
`tabryn doctor`	Diagnose setup and connection issues

Configuration

Environment Variables

Variable	Default	Description
`TABRYN_PORT`	`18766`	TCP port for MCP server ↔ Bridge communication

Security

Tabryn is designed with security as a first-class requirement:

No credential exposure — Cookies, passwords, and session tokens are never sent to agents
Permission boundaries — Users control which tabs are accessible
Input validation — All messages are validated before processing
Local-only communication — All traffic stays on localhost

See SECURITY.md for the full security model.

Architecture Decision Records

ADR-0001: Communication Protocol — Why Native Messaging + TCP

Contributing

See CONTRIBUTING.md for development setup and guidelines.

License

MIT © idugeni

Built with ❤️ for the AI agent community

GitHub Stars GitHub Forks