Widgetbook allows developers to fully customize how use cases are previewed. Use the appBuilder property of WidgetbookApp to specify your custom AppBuilder method.

While the appBuilder function is still available for use, developers also have the flexibility to define their Addons to inject functionality directly into the Widget tree.Follow the Addons documentation

Custom Material app builder
Widget build(BuildContext context) {
  return Widgetbook.material(
    // ... rest of the code
    appBuilder: (context, child) {
      return AwesomePackage(
        child: MaterialApp(
          debugShowCheckedModeBanner: false,
          home: child,

Widgetbook now uses your custom AppBuilder method.