{
  config,
  pkgs,
  ...
}: {
  services.keyd = {
    enable = true;
    keyboards = {
      # The name is just the name of the configuration file, it does not really matter
      default = {
        ids = ["*"]; # what goes into the [id] section, here we select all keyboards
        # Everything but the ID section:
        settings = {
          # The main layer, if you choose to declare it in Nix
          main = {
            capslock = "layer(LWin)"; # you might need to also enclose the key in quotes if it contains non-alphabetical symbols
          };
          otherlayer = {};
        };
        extraConfig = ''
          # put here any extra-config, e.g. you can copy/paste here directly a configuration, just remove the ids part
        '';
      };
    };
  };
}