I suspect that in your particular case of calculator and mail type keys, those keys might use a different USB device descriptor than standard keyboard keys, and so might be unusable for what you want to do. The documentation for hs.eventtap.event:systemKey() might be helpful to you. A Spoon package of my Hammerspoon modules, mainly for keyboard customization - GitHub - knu/Knu. When I learned about the Karabiner Elements and Hammerspoon combo, I knew I needed to set it up, but my initial set up process ended up taking much longer than a simple installation, so I decided to outline the steps.

If pressing the key you'd like to map causes its name to be printed in the console, then you know you can take actions when the key is pressed the only step remaining is to modify the snippet to test which key is being pressed, instead of always printing its name. As a keyboard shortcut lover, I’ve always enjoyed sharing my favorite shortcuts, and I’m always on the lookout for new ones. This will print the keycode of any keyboard key pressed. Running multiple Hammerspoon scripts Select the Hammerspoon icon from your Macs menu bar, and then click Reload config.

systemDefined then local t = event: systemKey() Which are best open-source Hammerspoon projects in Lua This list will help you: keyboard, awesome-hammerspoon, stackline, VimMode.spoon, Spoons. My solution is to use Hammerspoon to invert the entire display’s colors and keep flashing the display until I switch back to the terminal window.

Hammerspoon keystroke example