Here's my NixOS flake for a minimal gui consisting of hyprland (compositer), and waybar (status bar), and to keep it minimal, the only apps included are alacritty (terminal emulator), and minigui-settings (settings app).
Run the following command:
sudo nixos-rebuild --flake github:sandmuel/minigui-flake#nixos
Currently requires experimental feature; flakes, to be enabled.