📺 GhostScreen

Stealth screen sharing for macOS — share your screen in a second Google Meet without the first meeting knowing.

The Scenario

You're in Meet #1 sharing your screen. You need to also share your screen with someone in Meet #2 — without Meet #1 detecting anything.

How It Works

┌──────────────┐     ┌─────────────────┐     ┌──────────────────┐
│  Your Screen │────▶│  GhostScreen    │────▶│  Chrome Tab      │
│              │     │  (Electron app)  │     │  localhost:9777   │
│              │     │  captures screen │     │  shows your       │
│              │     │  via WebSocket   │     │  screen live      │
└──────────────┘     └─────────────────┘     └──────────────────┘
                       invisible to                  │
                       screen share            ┌─────▼──────────┐
                                               │  Meet #2       │
                                               │  "Share Tab"   │
                                               │  this tab      │
                                               └────────────────┘

1. GhostScreen runs as an invisible Electron app (content-protected, no focus steal)
2. It captures your screen at 15 FPS and streams via WebSocket
3. A local viewer page (localhost:9777) displays the live stream
4. In Meet #2, you "Share a Tab" → select the viewer tab
5. Meet #1 sees nothing different — GhostScreen is invisible to screen capture

Setup

cd ghost-screen
npm install
npm start

Usage

1. Start the app — it auto-starts streaming
2. Press ⌘⇧V or click "Open Viewer" to open the stream in Chrome
3. In Meet #2: click "Present" → "A Tab" → select the localhost:9777 tab
4. Done! Meet #1 is completely unaware

Keyboard Shortcuts

Shortcut	Action
⌘⇧S	Start / Stop streaming
⌘⇧V	Open viewer in browser
⌘⇧P	Show / Hide control panel

Viewer Shortcuts

Key	Action
S	Toggle FPS stats
F	Toggle fullscreen

Settings

In the control panel you can adjust:

• FPS (1-30): Higher = smoother but more CPU. 15 is recommended.
• Quality (10-100%): JPEG quality. 70% is a good balance.

Why This Works

Feature	How
Invisible to screen share	setContentProtection(true) — macOS excludes the window from capture
No focus steal	focusable: false + type: 'panel' — never takes focus from Meet
Hidden from dock	app.dock.hide() — no dock icon
Hidden from Cmd+Tab	skipTaskbar: true
All workspaces	setVisibleOnAllWorkspaces(true)

Architecture

• Main Process: Electron app that captures screen using desktopCapturer, runs Express HTTP server + WebSocket server
• Control Panel: Content-protected overlay window for managing the stream
• Viewer Page: Plain HTML page served at localhost:9777 that receives JPEG frames over WebSocket and displays them

macOS Permissions

On first run, grant these in System Settings → Privacy & Security:

• Screen Recording: Required for desktopCapturer
• Accessibility: May be needed for global shortcuts

Troubleshooting

Issue	Fix
Black screen in viewer	Grant Screen Recording permission, restart app
Choppy stream	Lower FPS to 10, lower quality to 50%
Port in use	Another instance may be running. Kill it: lsof -i :9777
High CPU	Lower FPS and quality in the control panel