diff --git a/lib/app/view/app.dart b/lib/app/view/app.dart
index 766a0a83c..f1d4d65b7 100644
--- a/lib/app/view/app.dart
+++ b/lib/app/view/app.dart
@@ -21,7 +21,13 @@ import 'package:webtrit_phone/resolvers/resolvers.dart';
 final _logger = Logger('AppWidget');
 
 class App extends StatefulWidget {
-  const App({super.key});
+  const App({super.key, this.embeddedPreview = false});
+
+  /// Whether the app runs embedded inside another Flutter host (realtime
+  /// preview). When true, Firebase-backed integrations such as the analytics
+  /// navigator observer are skipped to avoid touching a misconfigured/absent
+  /// Firebase app.
+  final bool embeddedPreview;
 
   @override
   State<App> createState() => _AppState();
@@ -147,7 +153,7 @@ class _AppState extends State<App> {
                   deepLinkBuilder: isDeepLinkEnabled ? appRouter.deepLinkBuilder : null,
                   navigatorObservers: () => [
                     AppRouterObserver(),
-                    context.read<AppAnalyticsRepository>().createObserver(),
+                    if (!widget.embeddedPreview) context.read<AppAnalyticsRepository>().createObserver(),
                     AutoRouteObserver(),
                   ],
                   reevaluateListenable: ReevaluateListenable.stream(
diff --git a/lib/bootstrap.dart b/lib/bootstrap.dart
index ea28a88d2..897f90023 100644
--- a/lib/bootstrap.dart
+++ b/lib/bootstrap.dart
@@ -39,20 +39,32 @@ import 'services/services.dart';
 // Dart isolates do not share memory -- each background isolate gets its own instance.
 IsolateContext? _isolateContext;
 
-Future<InstanceRegistry> bootstrap() async {
+/// Boots the application dependencies.
+///
+/// When [embeddedPreview] is true the app is hosted inside another Flutter app
+/// (e.g. the theme configurator's realtime preview) that already owns the
+/// default Firebase app — which may be misconfigured for this app or absent.
+/// In that mode all Firebase side effects are skipped and Firebase-backed
+/// services fall back to local, offline-safe implementations so the embedded
+/// app can render without a valid Firebase configuration.
+Future<InstanceRegistry> bootstrap({bool embeddedPreview = false}) async {
   final registry = InstanceRegistry();
 
   // External SDKs (Side effects only, don't need registration)
-  await _initFirebaseApp();
-  await _initFirebaseMessaging();
-  await _initLocalPushs();
+  if (!embeddedPreview) {
+    await _initFirebaseApp();
+    await _initFirebaseMessaging();
+    await _initLocalPushs();
+  }
 
   // Initialize Components
 
   // App Info & Device Data
 
   final packageInfo = await PackageInfoFactory.init();
-  final appInfo = await AppInfo.init(FirebaseAppIdProvider());
+  final appInfo = await AppInfo.init(
+    embeddedPreview ? const SharedPreferencesAppIdProvider() : FirebaseAppIdProvider(),
+  );
   final deviceInfo = await DeviceInfoFactory.init();
 
   // Storages
@@ -99,7 +111,22 @@ Future<InstanceRegistry> bootstrap() async {
 
   // Remote configuration
   final remoteCacheConfigService = await DefaultRemoteCacheConfigService.init();
-  final cachedRemoteConfigService = await CachedRemoteConfigService.init(remoteCacheConfigService);
+  // Firebase Remote Config (and its underlying Installations) may be unavailable
+  // when the app is embedded in another host (e.g. the theme configurator's
+  // realtime preview) that owns the default Firebase app, or when offline. Fall
+  // back to the local shared-preferences cache so bootstrap still completes;
+  // [DefaultRemoteCacheConfigService] also implements [RemoteConfigService].
+  RemoteConfigService cachedRemoteConfigService;
+  if (embeddedPreview) {
+    cachedRemoteConfigService = remoteCacheConfigService;
+  } else {
+    try {
+      cachedRemoteConfigService = await CachedRemoteConfigService.init(remoteCacheConfigService);
+    } catch (e, s) {
+      Logger('bootstrap').warning('Firebase Remote Config init failed; using local cache fallback', e, s);
+      cachedRemoteConfigService = remoteCacheConfigService;
+    }
+  }
 
   final featureAccessStreamFactory = FeatureAccessStreamFactory(
     appThemes: appThemes,
diff --git a/lib/main.dart b/lib/main.dart
index b199fc7e7..c67b0ce8e 100644
--- a/lib/main.dart
+++ b/lib/main.dart
@@ -66,10 +66,15 @@ void _onRootLogRecord(LogRecord record) {
 }
 
 class RootApp extends StatelessWidget {
-  const RootApp({super.key, required this.instanceRegistry});
+  const RootApp({super.key, required this.instanceRegistry, this.embeddedPreview = false});
 
   final InstanceRegistry instanceRegistry;
 
+  /// Whether the app runs embedded inside another Flutter host (e.g. the theme
+  /// configurator's realtime preview). Forwarded to [App] so Firebase-backed
+  /// integrations such as the analytics navigator observer are skipped.
+  final bool embeddedPreview;
+
   @override
   Widget build(BuildContext context) {
     return MultiProvider(
@@ -147,7 +152,12 @@ class RootApp extends StatelessWidget {
                 create: (_) => instanceRegistry.get(),
                 dispose: disposeIfDisposable,
               ),
-              RepositoryProvider.value(value: AppAnalyticsRepository(instance: FirebaseAnalytics.instance)),
+              // Lazy so embedders that skip Firebase (e.g. the configurator's realtime
+              // preview) never touch FirebaseAnalytics.instance, which throws when the
+              // host's default Firebase app is misconfigured/absent.
+              RepositoryProvider<AppAnalyticsRepository>(
+                create: (_) => AppAnalyticsRepository(instance: FirebaseAnalytics.instance),
+              ),
               RepositoryProvider<RegisterStatusRepository>.value(value: registerStatusRepository),
               RepositoryProvider<PresenceSettingsRepository>.value(value: presenceSettingsRepository),
               RepositoryProvider<QueuedTerminationRequestsRepository>.value(value: queuedTerminationRequestsRepository),
@@ -176,7 +186,7 @@ class RootApp extends StatelessWidget {
               RepositoryProvider<UserLocalDatasource>(create: (_) => instanceRegistry.get()),
               RepositoryProvider<AuthRepository>(create: (_) => instanceRegistry.get()),
             ],
-            child: const App(),
+            child: App(embeddedPreview: embeddedPreview),
           );
         },
       ),