Nice, I just use lxqt-openssh-askpass, but I am on X11. A lighter alternative (for single-text input) would be FLTK. Version 1.4 is really nice, with Wayland support, and they even draw custom window decorations on GNOME. Both Cairo and FLTK should be able to compile with -X; not sure, though, about the status of the Zig bindings.
fltk is c++ based which makes language bindings significantly harder in general. gtk is c based which worked out really well in that aspect.