The layout widget ran a device query every 10 seconds, in each bar, for as long as the seat had more than one keyboard. Hyprland raises no event when a keyboard arrives or leaves. The merged shell watches /dev/input, where keyboards appear and disappear, the udev records for input devices, and /dev itself so the watch can be armed again if that directory is recreated.

It signals once a burst has been quiet for 500ms, and again three seconds later, in case Hyprland trailed the event. The 10-second timer remains only until a first reading lands, and while a reading leaves the seat in doubt. David Heinemeier Hansson wrote that on a four-keyboard seat the previous shell spawned the device query every 10 seconds, and that an idle test of this branch passed without allowing that query.