mackeys

Disable keyboard keys on macOS using hidutil.

Map the key to an undefined usage so it does nothing:

hidutil property --set '{"UserKeyMapping":[{
  "HIDKeyboardModifierMappingSrc": 0x<KEY_CODE>,
  "HIDKeyboardModifierMappingDst": 0xFF000001
}]}'

To disable multiple keys, add more entries to the UserKeyMapping array.

The moon/DND key on MacBook keyboards is 0x10000009B:

hidutil property --set '{"UserKeyMapping":[{
  "HIDKeyboardModifierMappingSrc": 0x10000009B,
  "HIDKeyboardModifierMappingDst": 0xFF000001
}]}'

This disables DND while leaving fn+F6 intact.

Caps Lock is 0x700000039:

hidutil property --set '{"UserKeyMapping":[{
  "HIDKeyboardModifierMappingSrc": 0x700000039,
  "HIDKeyboardModifierMappingDst": 0xFF000001
}]}'

If you still want Caps Lock but want to prevent accidental activation, hidutil has a built-in debounce. This requires a 1-second hold:

hidutil property --set '{"CapsLockDelayOverride":1000}'

Adjust the value in milliseconds.

Multiple properties can be set in a single command:

# Debounce caps lock (require 1 second hold)
# Disable DoNotDisturb by mapping 0x10000009B to 0xFF000001 (undefined usage, silently dropped)
hidutil property --set '{
  "CapsLockDelayOverride":1000,
  "UserKeyMapping":[{
    "HIDKeyboardModifierMappingSrc":0x10000009b,
    "HIDKeyboardModifierMappingDst":0xff000001
}]}'

Clear all disabled keys:

hidutil property --set '{"UserKeyMapping":[]}'

Clear CapsLock debounce:

hidutil property --set '{"CapsLockDelayOverride":0}'

These settings do not survive a reboot. Run the commands again after restarting, or save them to a script.

If you don't know the key code for the key you want to disable, build and run the helper:

make
./snoop-key

Press any key and it prints the hidutil code. It is fn-aware, so pressing the moon key without fn shows DoNotDisturb 0x10000009B, while fn+moon shows F6 0x70000003F.

There is also a script that wraps snoop-key and outputs the full hidutil command for you:

./disable-key.sh

Press the key when prompted and it prints the command:

# Disable DoNotDisturb by mapping 0x10000009B to 0xFF000001 (undefined usage, silently dropped)
hidutil property --set '{"UserKeyMapping":[{"HIDKeyboardModifierMappingSrc":0x10000009b,"HIDKeyboardModifierMappingDst":0xff000001}]}'

snoop-key requires Input Monitoring permission. Add your terminal app at:

System Settings > Privacy & Security > Input Monitoring