light.nix

  programs.light.enable = true;
  services.actkbd = {
    enable = true;
    bindings = [
      # Find the keycodes using:
      # sudo actkbd -v9 -n -s -d /dev/input/event__
      # Where `/dev/input/event__` is one of the descriptors
      { keys = [ 114 ]; events = [ "key" ]; command = "/run/wrappers/bin/light -A 5"; }
      { keys = [ 115 ]; events = [ "key" ]; command = "/run/wrappers/bin/light -U 5"; }
    ];
  };