anchor.diff:          default = null;
           description = ''
             Game password.
  +        '';
  +      };
  +      requireUserVerification = mkOption {
  +        type = types.bool;
  +        default = true;
  +        description = ''
  +          When set to true, the server will only allow clients that have a valid factorio.com account.
           '';
         };
         autosave-interval = mkOption {
  
positive.code:           customizations.
          '';
        };
        mods = mkOption {
          type = types.listOf types.package;
          default = [];
  
negative.code:   cfg = config.services.factorio;
    factorio = pkgs.factorio-headless;
    name = "Factorio";
    stateDir = cfg.stateDir;
    mkSavePath = name: "${stateDir}/saves/${name}.zip";
    configFile = pkgs.writeText "factorio.conf" ''
      use-system-read-write-data-directories=true
  