nixos-config/nixos/components/gui/kmonad.nix

{ config, pkgs, ... }:
{
  services.xserver = {
    layout = "us";
    xkbOptions = "compose:ralt";
  };
  services.kmonad = {
    enable = true;
    keyboards.dasKeyboard = {
      device = "/dev/input/by-id/usb-Metadot_-_Das_Keyboard_Das_Keyboard-event-kbd";
      extraGroups = [ "video" ];
      defcfg = {
        enable = true;
        fallthrough = true;
        allowCommands = true;
      };
      config = ''
        (defsrc
          grv  1    2    3    4    5    6    7    8    9    0    -    =    bspc
          tab  q    w    e    r    t    y    u    i    o    p    [    ]    \
          caps a    s    d    f    g    h    j    k    l    ;    '    ret
          lsft z    x    c    v    b    n    m    ,    .    /    rsft
          lctl lmet lalt           spc            ralt rmet cmp  rctl
        )

        (defalias sym (layer-toggle symbols))

        (deflayer qwerty
          grv  1    2    3    4    5    6    7    8    9    0    -    =    bspc
          tab  q    w    e    r    t    y    u    i    o    p    [    ]    \
          esc  a    s    d    f    g    h    j    k    l    ;    '    ret
          lsft z    x    c    v    b    n    m    ,    .    /    rsft
          lctl lmet lalt           spc            @sym rmet cmp  rctrl
        )

        (deflayer symbols
          _    ½    ²    ³    ⁴    ⁵    ⁶    ⁷    ⁸    ⁹    ∞    _    _    _
          _    _    _    €    _    ™    _    ü    _    ö    _    _    _    _
          caps ä    ß    _    _    _    _    _    _    _    _    _    _
          _    _    _    ¢    _    _    _    _    _    _    _    _
          _    _    _              _              _    _    _    _)
      '';
    };

  };
}