How Invisible AI Overlays Work — The Technology Behind Meeting Copilot

One of the most common questions we get: "How is the overlay invisible to screen-sharing?" Here's the technical explanation.

Desktop Overlays vs. Browser Extensions

Browser extensions run inside the browser. They modify the DOM, add toolbars, and inject UI elements. When you share your browser window or full screen, everything the extension renders is visible to other participants.

Desktop overlays are different. They're standalone windows rendered by the operating system, positioned on top of other applications. They exist outside the browser entirely.

How Screen-Sharing Works

When you share your screen in Zoom, Meet, or Teams, the software captures either:

1. A specific window — Only the pixels of that window are shared
2. An entire screen — All visible windows on that display are captured

For window sharing, the overlay is never captured because it's a separate window. For full-screen sharing, the overlay can be configured at the OS level to be excluded from screen capture.

Electron and Window Configuration

Meeting Copilot is built with Electron, which provides fine-grained control over window behavior:

• alwaysOnTop: true — The overlay stays above all other windows
• transparent: true — The window background is transparent
• focusable: false — Clicking through the overlay doesn't steal focus from your meeting app
• OS-level flags exclude the window from screen capture APIs

On macOS, this uses the CGWindowSharingType API. On Windows, it uses the WDA_EXCLUDEFROMCAPTURE flag available in Windows 10 2004+.

Real-Time AI Pipeline

The overlay isn't just a display — it's connected to a real-time AI pipeline:

1. Audio capture — Mic and system audio are captured simultaneously
2. Transcription — OpenAI Whisper transcribes speech in near real-time
3. Context assembly — The transcript is combined with your Briefing Pack documents
4. Suggestion generation — GPT-4o generates a speakable suggestion
5. Display — The suggestion appears in the overlay within 2 seconds

Speaker attribution ([ME] vs [OTHER]) is handled by separating mic input from system audio, so the AI knows who said what.

Privacy by Design

The entire pipeline is designed with privacy in mind:

• Recording only happens when you explicitly start a meeting
• Audio is processed and discarded — only the transcript is stored
• Transcripts have configurable retention (30, 90, or 365 days)
• You can delete any meeting and its data at any time
• No data is shared with third parties

Try It Yourself

The best way to understand how the overlay works is to try it. Download Meeting Copilot, start a test meeting, and see the overlay in action.

Download Meeting Copilot for macOS or Windows.