ThirdEye Browser Tools

AI-powered Chrome extension and MCP server for webpage manipulation. Allows AI agents like Cursor to take screenshots and refresh webpages remotely.

SSE-based MCP server - connects via URL like Linear MCP, with real-time streaming for large images and progress updates.

Features

• 📸 Screenshot Capture: Take screenshots via AI agent commands with real-time streaming
• 🔄 Page Refresh: Refresh or navigate to pages programmatically
• ⚡ SSE-based MCP: Server-Sent Events for instant responses and progress streaming
• 🌐 Chrome Extension: Browser extension with real-time communication
• 🚀 Simple Setup: One server handles MCP + extension + installation
• 📊 Progress Updates: See screenshot progress in real-time ("Taking screenshot...", "Processing...")

Quick Start

1. Start the Server

# Install and run (no global installation needed)
npx @rapidsd/thirdeye@latest

# Or install globally
npm install -g @rapidsd/thirdeye
thirdeye

One server provides all functionality:

• 🔌 MCP SSE endpoint: http://localhost:7654/sse (for AI agents)
• 📱 Extension API: Real-time communication with Chrome extension
• 🌐 Installation page: http://localhost:7654/install (setup instructions)
• ❤️ Health check: http://localhost:7654/health

2. Install Chrome Extension

1. Visit http://localhost:7654/install for detailed instructions
2. Or manually:
   • Open chrome://extensions/
   • Enable "Developer mode"
   • Click "Load unpacked"
   • Select the extension/ folder from this package

3. Configure Cursor (or other MCP-compatible AI tool)

Add to your Cursor MCP settings (like Linear):

{
  "mcpServers": {
    "@rapidsd/thirdeye": {
      "url": "http://localhost:7654/sse"
    }
  }
}

That's it! No command-line spawning - just a clean URL connection like Linear MCP.

Usage

Once configured, you can use these commands in Cursor:

• "Take a screenshot of the current page"
• "Refresh the current webpage"
• "Navigate to https://example.com and take a screenshot"

Architecture

AI Agent (Cursor) → POST /sse → HTTP Server → SSE Events → Chrome Extension → Webpage
                 ← SSE Stream ←             ← HTTP Response ←

Real-time flow:

1. Cursor sends tool call via POST /sse
2. Server streams progress updates via SSE
3. Extension receives request via SSE events
4. Extension captures screenshot and responds
5. Server streams final result back to Cursor

Development

Build from Source

git clone <repository>
cd thirdeye
npm install
npm run build

# Start the server:
npm start

Project Structure

thirdeye/
├── server/
│   └── index.ts              # Unified server (SSE MCP + Extension API + Installation)
├── dist/                     # Compiled JavaScript output
│   └── index.js             # Main executable
├── extension/
│   ├── manifest.json         # Chrome extension manifest
│   ├── background.js         # Service worker
│   ├── content.js           # Content script
│   ├── popup.html           # Extension popup UI
│   ├── popup.js             # Popup functionality
│   └── icons/               # Extension icons
└── package.json              # Minimal dependencies

API Reference

MCP SSE Endpoint

POST /sse

Main MCP endpoint for all tool calls with streaming responses.

Request format:

{
  "method": "tools/call",
  "params": {
    "name": "take_screenshot",
    "arguments": {}
  }
}

Response format (SSE stream):

event: progress
data: {"status":"requesting_screenshot","message":"Requesting screenshot from extension..."}

event: result  
data: {"content":[{"type":"image","data":"iVBORw0KG...","mimeType":"image/png"}]}

event: complete
data: {"done":true}

MCP Tools

take_screenshot

Takes a screenshot of the current active webpage with streaming progress.

Parameters: None (always uses active tab, always PNG format)

Returns: PNG image data with progress updates

refresh_page

Refreshes the current active webpage or navigates to a new URL.

Parameters:

• url (optional): Navigate to this URL (if not provided, just refreshes current page)

Returns: Success confirmation

Other HTTP Endpoints

GET /api/extension-events

SSE endpoint for Chrome extension real-time communication.

GET /install

Installation page with setup instructions.

GET /health

Health check endpoint.

Troubleshooting

Server Won't Start

• Ensure port 7654 is available
• Check Node.js version (requires ≥18.0.0)

Extension Not Working

• Verify server is running (http://localhost:7654/health)
• Check Chrome extension permissions
• Look for errors in extension console

MCP Integration Issues

• Verify Cursor configuration points to http://localhost:7654/sse
• Test SSE endpoint: curl -X POST http://localhost:7654/sse -H "Content-Type: application/json" -d '{"method":"tools/list","params":{}}'
• Check Cursor's MCP server logs
• Ensure ThirdEye server is running on port 7654

Contributing

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Add tests if applicable
5. Submit a pull request

License

Business Source License 1.1 (BSL-1.1) - see LICENSE file for details.

Commercial use requires a separate license. The software will automatically become Apache 2.0 licensed on 2028-01-01.