machine_setup/nix/configuration/roles/steam_run_free/default.nix

{
  config,
  lib,
  pkgs,
  ...
}:

{
  imports = [ ];

  options.me = {
    steam_run_free.enable = lib.mkOption {
      type = lib.types.bool;
      default = false;
      example = true;
      description = "Whether we want to install steam_run_free.";
    };
  };

  config = lib.mkIf config.me.steam_run_free.enable {
    environment.systemPackages = with pkgs; [
      steam-run-free
    ];
  };
}