Ideas for screen ruler on Wayland

I am thinking of writing a program which behaves similarly to https://github.com/bluegrams/ScreenRuler, but works natively in Linux. However, my understanding of Wayland is that only the compositor itself could perform such an action.

Is there a way that software could interact with the entire screen in Wayland in a way that works across different compositors (GNOME, KDE, etc)? Or am I correct that a code would have to be written for each compositor it interacted with?