The BOINC distributed computing client in Debian (Bookworm and previous releases) can check the idle time via the X11 protocol and run GPU jobs when the interactive user is idle, so the user gets GPU power for graphics when they need it and when it’s idle BOINC uses it. This doesn’t work for Wayland and unfortunately no-one has written a Wayland equivalent of xprintidle (which shows the number of milliseconds that the X11 session has been idle in milliseconds.
In the Debian bug system there is bug #813728 about a message every second due to failed attempts to find X11 idle time [1]. On my main workstation with Wayland it logs “Authorization required, but no authorization protocol specified“.
There is also bug #775125 about BOINC not detecting mouse movements [2], I added to it about the issues with Wayland. There’s the package swayidle in Debian that is designed to manage the screen-save process on Wayland, below is an example of how to use it to display output on 5 seconds and 10 seconds of idle.
swayidle -w timeout 5 'echo 5' timeout 10 'echo 10' resume 'echo resume' before-sleep 'echo before-sleep'
The code for swayidle has only 7 comments and isn’t easy to read. I looked in to writing a Wayland equivalent of xprintidle but it would take more work than I’m prepared to invest in it. So it seems to me that the best option might be to have BOINC receive SIGUSR1 and SIGUSR2 for the start and stop of idle time and then have scripts call xprintidle, swayidle, a wrapper for “w” (for systems without graphics) or other methods. To run swayidle as root you can set WAYLAND_DISPLAY=../$USER_ID/wayland-0.