If you're using a 60% keyboard, or any other layout with no F-row, you will have noticed that there is no dedicated Escape key. Grave Escape is a feature that allows you to share the grave key (
~) with Escape.
KC_GRAVE key in your keymap (usually to the left of the
1 key) with
KC_GESC. Most of the time this key will output
KC_ESC when pressed. However, when Shift or GUI are held down it will output
If Mary presses GESC on her keyboard, the OS will see an KC_ESC character. Now if Mary holds Shift down and presses GESC it will output
~, or a shifted backtick. Now if she holds GUI/CMD/WIN, it will output a simple
Escape when pressed,
On macOS CMD/GUI + KC_GRV is actually mapped to a hot key so it will not output a backtick.
There are several possible key combinations this will break, among them Control+Shift+Escape on Windows and Command+Option+Escape on macOS. To work around this, you can
#define these options in your
Always send Escape if Alt is pressed
Always send Escape if Control is pressed
Always send Escape if GUI is pressed
Always send Escape if Shift is pressed