KeyOn

A keyboard-driven UI navigation tool for macOS, similar to Shortcat. Navigate and click any UI element using only your keyboard.

Features

• Keyboard-driven navigation - Click any button, link, or UI element by typing its label
• Global hotkey - Activate with Cmd+< from anywhere
• Smart labels - Left-hand keyboard priority for faster typing (A, S, D, F, etc.)
• Scroll support - Use Shift+Arrow keys to scroll while overlay is active
• Mouse movement - Arrow keys move the mouse cursor
• Left & right click - Space for left click, Enter for right click
• Auto-refresh - Labels recalculate after scrolling to catch new elements
• Lightweight - Built with Zig and raylib for minimal resource usage
• Menu bar icon - Easy access to quit the app

Installation

Prerequisites

• macOS 11.0 or later
• Zig 0.13 or later
• raylib 5.0 or later
• cliclick (for reliable clicking)

Install dependencies

brew install zig raylib cliclick

Build from source

git clone https://github.com/kidandcat/keyon.git
cd keyon
zig build -Doptimize=ReleaseFast

Install as application

# Create app bundle
mkdir -p /Applications/KeyOn.app/Contents/MacOS
cp zig-out/bin/keyon /Applications/KeyOn.app/Contents/MacOS/
cp Info.plist /Applications/KeyOn.app/Contents/

# Sign the app (required for accessibility permissions)
codesign --force --sign - /Applications/KeyOn.app

Usage

First Run

1. Launch KeyOn from /Applications/KeyOn.app
2. Grant Accessibility permissions when prompted:
   • System Settings → Privacy & Security → Accessibility → Enable KeyOn
3. The app will appear in your menu bar

Keyboard Shortcuts

Shortcut	Action
Cmd+<	Toggle overlay (show/hide labels)
A-Z	Type label characters to filter
Space	Left click on element (or at cursor if no label typed)
Enter	Right click on element (or at cursor if no label typed)
Arrow keys	Move mouse cursor
Shift+Arrow	Scroll in that direction
Backspace	Delete last typed character
Escape	Close overlay

Tips

• Labels prioritize left-hand keys (A, S, D, F, G, Q, W, E, R, T) for faster typing
• Two-letter combos start with left-hand combinations (AS, AD, AF, etc.)
• After scrolling, wait 1 second and labels will refresh to show new elements
• The hint bar at the bottom shows what you've typed

How It Works

KeyOn uses macOS Accessibility APIs to:

1. Detect the frontmost application
2. Scan for clickable UI elements (buttons, links, text fields, etc.)
3. Display labeled overlays on each element
4. Perform clicks using native mouse events

Architecture

src/
├── main.zig          # Application entry point
├── overlay.zig       # Overlay window rendering (raylib)
├── hotkey.zig        # Global keyboard event handling
├── click.zig         # Mouse click and scroll operations
├── accessibility.zig # macOS Accessibility API integration
├── ui_element.zig    # UI element data structure
├── statusbar.m       # Menu bar icon (Objective-C)
└── statusbar.h       # Menu bar header

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

MIT License - see LICENSE for details.

Acknowledgments

• Inspired by Shortcat
• Scroll implementation based on robotgo
• Built with Zig and raylib