Cass is your on-screen AI companion. It runs as a floating Electron overlay you can toggle and reposition while it helps with whatever you throw at it—coding drills, multiple-choice questions, planning prompts, or quick definitions mid-call.
Note: Cass no longer attempts to enforce invisibility via OS-level screen filtering. Some meeting tools may capture the window as a normal overlay. If your tool offers advanced screen filtering, you can enable it manually.
- Press
Cmd/Ctrl + Enter– Capture screenshots and (optionally) audio notes. - AI Analysis – Screenshots, audio context, and stored session history are streamed to Google Gemini.
- Get Smart Responses – Cass formats output for the task at hand (code fences for LeetCode, clear picks for MCQ, numbered steps for math, structured plans, etc.).
- Continue Conversations – Add context with another
Cmd/Ctrl + Enteror reset withCmd/Ctrl + R.
Perfect for:
- Technical assessments, LeetCode drills, and code walkthroughs
- Client presentations and sales calls
- Educational lectures, training sessions, and study groups
- Everyday productivity moments where you need a private copilot
- Lightweight Overlay: Floating Electron window you can toggle and reposition
- Audio + Visual Processing: Combines system audio, microphone input, and screenshot analysis
- macOS: System audio is captured via Electron loopback (no separate binary). Microphone is mixed in the renderer using Web Audio.
- Contextual AI Responses: Powered by Google Gemini with task-aware formatting (code fences for programming, numbered steps for math, MCQ rationales, polished writing assistance, etc.)
- Follow-up Conversations: Press
Cmd/Ctrl + Enteragain to continue the conversation with new context; responses stream live so you can read as they generate - Reset Functionality: Press
Cmd/Ctrl + Rto start a fresh session - Cross-platform: Works on macOS and Windows
- Persistent Configuration: Remembers API keys and model preferences
- Cass detects common task types and shapes the answer accordingly.
- Coding solutions include fenced code blocks with language hints plus complexity and example walkthroughs.
- Math responses show step-by-step work, labeled formulas, and a clearly called out final answer.
- Multiple-choice answers lead with the correct option, followed by concise reasoning for every choice.
- General planning and writing prompts are formatted with headings or bullet lists to stay scannable.
- Cmd/Ctrl + Enter: Take screenshot and process with AI (includes audio snapshot if recording is active)
- Cmd/Ctrl + B: Take a screenshot (adds to queue without processing)
- Cmd/Ctrl + R: Reset session and clear context
- Cmd/Ctrl + \: Toggle window visibility
- Cmd/Ctrl + Q: Quit the application
- Arrow keys with Cmd/Ctrl: Move window around the screen
Recording: use the microphone button in the overlay to start/stop audio capture; there’s no default keyboard shortcut for this.
- Download and install Cass for your platform
- Grant permissions when prompted (Screen Recording on macOS is required)
- Set up your API key in the configuration tooltip
- Press
Cmd/Ctrl + Enterto take your first screenshot and start using AI assistance
If screenshots fail or audio is unavailable, ensure Cass has the relevant permissions in System Settings > Privacy & Security (Screen Recording, Microphone). Then restart Cass.
Cass no longer ships a native screen-protection helper. Behavior during screen sharing depends on the conference tool. Some tools offer options to hide overlays; enable them if needed.
/electron- Electron main process files (audio recording, screenshot capture, AI processing)/src- React frontend components (renderer process UI)- (no native helpers required)
/assets- Application icons and resources/build- Build configuration and entitlements