diff --git a/.github/workflows/test_dart.yml b/.github/workflows/test_dart.yml
index 751df78226..024cde81bd 100644
--- a/.github/workflows/test_dart.yml
+++ b/.github/workflows/test_dart.yml
@@ -38,6 +38,11 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
+      - name: Set up Flutter
+        uses: subosito/flutter-action@v2
+        with:
+          channel: 'stable'
+
       - name: Set up Dart ${{ matrix.dart-version }}
         uses: dart-lang/setup-dart@v1.6.0
         with:
@@ -49,7 +54,11 @@ jobs:
           for dir in $(find Dart -name pubspec.yaml -exec dirname {} \;); do
             echo "::group::Testing $dir"
             cd "$dir"
-            dart pub get
+            if grep -q "sdk: flutter" pubspec.yaml; then
+              flutter pub get
+            else
+              dart pub get
+            fi
             dart format --set-exit-if-changed .
             dart analyze .
             cd - > /dev/null
diff --git a/Dart/multi_counter/.gitignore b/Dart/multi_counter/.gitignore
new file mode 100644
index 0000000000..bdad04710f
--- /dev/null
+++ b/Dart/multi_counter/.gitignore
@@ -0,0 +1,9 @@
+.dart_tool
+.firebaserc
+.firebase
+*-debug.log
+
+app/.flutter-plugins-dependencies
+app/build
+
+server/bin/server
diff --git a/Dart/multi_counter/README.md b/Dart/multi_counter/README.md
new file mode 100644
index 0000000000..8b5935c29a
--- /dev/null
+++ b/Dart/multi_counter/README.md
@@ -0,0 +1,10 @@
+# Multi-counter
+
+This is sample code from a talk at Cloud Next 2026.
+
+[Unify your tech stack with Dart](https://www.googlecloudevents.com/next-vegas/session-library?session_id=3911912&name=unify-your-tech-stack-with-dart)
+
+This sample contains three projects:
+- `app/` A Flutter application for a shared multi-counter.
+- `server/` A Cloud Functions for Firebase project containing functions for the multi-counter written in Dart.
+- `shared/` A shared Dart package containing logic and models used by both the app and the server.
diff --git a/Dart/multi_counter/analysis_options.yaml b/Dart/multi_counter/analysis_options.yaml
new file mode 100644
index 0000000000..9a8cf6f6e6
--- /dev/null
+++ b/Dart/multi_counter/analysis_options.yaml
@@ -0,0 +1,8 @@
+include: package:dart_flutter_team_lints/analysis_options.yaml
+
+linter:
+  rules:
+    - avoid_redundant_argument_values
+    - prefer_expression_function_bodies
+    - unnecessary_breaks
+    - unnecessary_ignore
diff --git a/Dart/multi_counter/app/.metadata b/Dart/multi_counter/app/.metadata
new file mode 100644
index 0000000000..c25593b787
--- /dev/null
+++ b/Dart/multi_counter/app/.metadata
@@ -0,0 +1,30 @@
+# This file tracks properties of this Flutter project.
+# Used by Flutter tool to assess capabilities and perform upgrades etc.
+#
+# This file should be version controlled and should not be manually edited.
+
+version:
+  revision: "0c2d316b1565bc97fcf6125fa87dfb90ef05ed8f"
+  channel: "main"
+
+project_type: app
+
+# Tracks metadata for the flutter migrate command
+migration:
+  platforms:
+    - platform: root
+      create_revision: 0c2d316b1565bc97fcf6125fa87dfb90ef05ed8f
+      base_revision: 0c2d316b1565bc97fcf6125fa87dfb90ef05ed8f
+    - platform: web
+      create_revision: 0c2d316b1565bc97fcf6125fa87dfb90ef05ed8f
+      base_revision: 0c2d316b1565bc97fcf6125fa87dfb90ef05ed8f
+
+  # User provided section
+
+  # List of Local paths (relative to this file) that should be
+  # ignored by the migrate tool.
+  #
+  # Files that are not part of the templates will be ignored by default.
+  unmanaged_files:
+    - 'lib/main.dart'
+    - 'ios/Runner.xcodeproj/project.pbxproj'
diff --git a/Dart/multi_counter/app/lib/firebase_options.dart b/Dart/multi_counter/app/lib/firebase_options.dart
new file mode 100644
index 0000000000..11c0816586
--- /dev/null
+++ b/Dart/multi_counter/app/lib/firebase_options.dart
@@ -0,0 +1,23 @@
+// File generated by FlutterFire CLI.
+// ignore_for_file: type=lint
+import 'package:firebase_core/firebase_core.dart' show FirebaseOptions;
+import 'package:flutter/foundation.dart' show defaultTargetPlatform, kIsWeb;
+
+/// Default [FirebaseOptions] for use with your Firebase apps.
+///
+/// Example:
+/// ```dart
+/// import 'firebase_options.dart';
+/// // ...
+/// await Firebase.initializeApp(
+///   options: DefaultFirebaseOptions.currentPlatform,
+/// );
+/// ```
+class DefaultFirebaseOptions {
+  static FirebaseOptions get currentPlatform {
+    throw UnsupportedError(
+      'DefaultFirebaseOptions have not been configured for $defaultTargetPlatform - '
+      'you can reconfigure this by running the FlutterFire CLI again.',
+    );
+  }
+}
diff --git a/Dart/multi_counter/app/lib/main.dart b/Dart/multi_counter/app/lib/main.dart
new file mode 100644
index 0000000000..f231f9563c
--- /dev/null
+++ b/Dart/multi_counter/app/lib/main.dart
@@ -0,0 +1,12 @@
+import 'package:flutter/material.dart';
+
+import 'src/app.dart';
+import 'src/config_state.dart';
+
+void main() async {
+  WidgetsFlutterBinding.ensureInitialized();
+
+  await initializeWorld();
+
+  runApp(const MyApp());
+}
diff --git a/Dart/multi_counter/app/lib/src/app.dart b/Dart/multi_counter/app/lib/src/app.dart
new file mode 100644
index 0000000000..2f9b936db0
--- /dev/null
+++ b/Dart/multi_counter/app/lib/src/app.dart
@@ -0,0 +1,42 @@
+import 'package:flutter/material.dart';
+
+import 'router.dart';
+
+class MyApp extends StatelessWidget {
+  const MyApp({super.key});
+
+  @override
+  Widget build(BuildContext context) => MaterialApp.router(
+    debugShowCheckedModeBanner: false,
+    title: 'Flutter Demo',
+    routerConfig: router,
+    theme: ThemeData(
+      useMaterial3: true,
+      colorScheme: const ColorScheme.light(
+        primary: Color(0xFF18181B), // Zinc 900
+        secondary: Color(0xFF3F3F46), // Zinc 700
+        onSecondary: Colors.white,
+      ),
+      appBarTheme: const AppBarTheme(
+        backgroundColor: Colors.white,
+        foregroundColor: Color(0xFF18181B),
+        elevation: 0,
+      ),
+    ),
+    darkTheme: ThemeData(
+      useMaterial3: true,
+      colorScheme: const ColorScheme.dark(
+        primary: Color(0xFFFAFAFA), // Zinc 50
+        secondary: Color(0xFFD4D4D8), // Zinc 300
+        surface: Color(0xFF09090B), // Zinc 950
+        onPrimary: Color(0xFF18181B),
+        onSecondary: Color(0xFF18181B),
+      ),
+      appBarTheme: const AppBarTheme(
+        backgroundColor: Color(0xFF09090B),
+        foregroundColor: Color(0xFFFAFAFA),
+        elevation: 0,
+      ),
+    ),
+  );
+}
diff --git a/Dart/multi_counter/app/lib/src/config_state.dart b/Dart/multi_counter/app/lib/src/config_state.dart
new file mode 100644
index 0000000000..e6cad38100
--- /dev/null
+++ b/Dart/multi_counter/app/lib/src/config_state.dart
@@ -0,0 +1,34 @@
+import 'package:cloud_firestore/cloud_firestore.dart';
+import 'package:cloud_functions/cloud_functions.dart';
+import 'package:firebase_auth/firebase_auth.dart';
+import 'package:firebase_core/firebase_core.dart';
+import 'package:flutter/foundation.dart';
+import 'package:multi_counter_shared/multi_counter_shared.dart';
+
+import '../firebase_options.dart';
+
+Future<void> initializeWorld() async {
+  await Firebase.initializeApp(options: DefaultFirebaseOptions.currentPlatform);
+
+  if (kDebugMode) {
+    await FirebaseAuth.instance.useAuthEmulator('127.0.0.1', 9099);
+    FirebaseFirestore.instance.useFirestoreEmulator('127.0.0.1', 8080);
+    FirebaseFunctions.instance.useFunctionsEmulator('127.0.0.1', 5001);
+  }
+}
+
+final _options = HttpsCallableOptions(timeout: const Duration(seconds: 15));
+
+HttpsCallable get incrementHttpsCallable {
+  if (kDebugMode) {
+    return FirebaseFunctions.instance.httpsCallable(
+      incrementCallable,
+      options: _options,
+    );
+  } else {
+    return FirebaseFunctions.instance.httpsCallableFromUrl(
+      'https://increment-138342796561.us-central1.run.app',
+      options: _options,
+    );
+  }
+}
diff --git a/Dart/multi_counter/app/lib/src/constants.dart b/Dart/multi_counter/app/lib/src/constants.dart
new file mode 100644
index 0000000000..fd6f66d381
--- /dev/null
+++ b/Dart/multi_counter/app/lib/src/constants.dart
@@ -0,0 +1,8 @@
+const appTitle = 'Multi-Counter';
+const maxContentWidth = 440.0;
+const double spaceSize = 16;
+const double doubleSpaceSize = spaceSize * 2;
+
+// TODO: Update this to the final example URI
+const githubDisplayUrl = 'github.com/kevmoo/next26_demo';
+final githubUri = Uri.parse('https://$githubDisplayUrl');
diff --git a/Dart/multi_counter/app/lib/src/router.dart b/Dart/multi_counter/app/lib/src/router.dart
new file mode 100644
index 0000000000..bb46e180f5
--- /dev/null
+++ b/Dart/multi_counter/app/lib/src/router.dart
@@ -0,0 +1,48 @@
+import 'dart:async';
+
+import 'package:firebase_auth/firebase_auth.dart' hide EmailAuthProvider;
+import 'package:flutter/material.dart';
+import 'package:go_router/go_router.dart';
+
+import 'screens/counter/screen.dart';
+import 'screens/login.dart';
+
+final router = GoRouter(
+  initialLocation: '/',
+  routes: [
+    GoRoute(path: '/', builder: (context, state) => const CounterScreen()),
+    GoRoute(path: '/login', builder: (context, state) => const LoginScreen()),
+  ],
+  redirect: (context, state) async {
+    // Ensure we capture the redirect result before checking the auth state.
+    await FirebaseAuth.instance.getRedirectResult();
+
+    final loggedIn = FirebaseAuth.instance.currentUser != null;
+    final loggingIn = state.matchedLocation == '/login';
+
+    if (!loggedIn) return '/login';
+    if (loggingIn) return '/';
+
+    return null;
+  },
+  refreshListenable: GoRouterRefreshStream(
+    FirebaseAuth.instance.authStateChanges(),
+  ),
+);
+
+class GoRouterRefreshStream extends ChangeNotifier {
+  GoRouterRefreshStream(Stream<dynamic> stream) {
+    notifyListeners();
+    _subscription = stream.asBroadcastStream().listen(
+      (dynamic _) => notifyListeners(),
+    );
+  }
+
+  late final StreamSubscription<dynamic> _subscription;
+
+  @override
+  void dispose() {
+    _subscription.cancel();
+    super.dispose();
+  }
+}
diff --git a/Dart/multi_counter/app/lib/src/screens/counter/screen.dart b/Dart/multi_counter/app/lib/src/screens/counter/screen.dart
new file mode 100644
index 0000000000..97a5479db8
--- /dev/null
+++ b/Dart/multi_counter/app/lib/src/screens/counter/screen.dart
@@ -0,0 +1,109 @@
+import 'dart:async';
+
+import 'package:flutter/material.dart';
+import 'package:multi_counter_shared/multi_counter_shared.dart';
+
+import '../../constants.dart';
+import '../../widgets/app_scaffold.dart';
+import 'state.dart';
+
+class CounterScreen extends StatefulWidget {
+  const CounterScreen({super.key});
+
+  @override
+  State<CounterScreen> createState() => _CounterScreenState();
+}
+
+class _CounterScreenState extends State<CounterScreen> {
+  final state = CounterState();
+  late final StreamSubscription<IncrementResponse> _sub;
+  late final Listenable _merger;
+
+  @override
+  void initState() {
+    super.initState();
+
+    _merger = Listenable.merge([state.userCounter, state.globalCounter]);
+
+    ScaffoldFeatureController<SnackBar, SnackBarClosedReason>?
+    snackBarController;
+
+    _sub = state.incrementResponseStream.listen((response) {
+      if (!mounted) return;
+
+      final message = response.message;
+      if (message != null && snackBarController == null) {
+        snackBarController = ScaffoldMessenger.of(context).showSnackBar(
+          SnackBar(
+            content: Text(message),
+            backgroundColor: response.success ? null : Colors.red,
+          ),
+        );
+
+        snackBarController?.closed.then((reason) {
+          snackBarController = null;
+        });
+      }
+    });
+  }
+
+  @override
+  void dispose() {
+    _sub.cancel();
+    state.dispose();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) => AppScaffold(
+    child: ListenableBuilder(
+      listenable: _merger,
+      builder: (context, child) {
+        final globalCount = state.globalCounter.value;
+        return SingleChildScrollView(
+          child: Column(
+            mainAxisSize: MainAxisSize.min,
+            mainAxisAlignment: MainAxisAlignment.center,
+            children: [
+              Text(
+                appTitle,
+                style: Theme.of(context).textTheme.headlineMedium,
+                textAlign: TextAlign.center,
+              ),
+              _spacer,
+              const Text('You have pushed the button this many times:'),
+              Text(
+                '${state.userCounter.value}',
+                style: Theme.of(context).textTheme.headlineMedium,
+              ),
+              _spacer,
+              if (globalCount == null) const Text('...'),
+              if (globalCount != null) ...[
+                const Text('Total button pushes:'),
+                Text(
+                  '${globalCount.totalClicks}',
+                  style: Theme.of(context).textTheme.headlineMedium,
+                ),
+                _spacer,
+                const Text('Total people who have pushed the button:'),
+                Text(
+                  '${globalCount.totalUsers}',
+                  style: Theme.of(context).textTheme.headlineMedium,
+                ),
+              ],
+              _spacer,
+              FloatingActionButton.extended(
+                onPressed: state.increment,
+                tooltip: 'Increment',
+                icon: const Icon(Icons.add),
+                label: const Text('Increment'),
+              ),
+            ],
+          ),
+        );
+      },
+    ),
+  );
+}
+
+const _spacer = SizedBox(height: doubleSpaceSize);
diff --git a/Dart/multi_counter/app/lib/src/screens/counter/state.dart b/Dart/multi_counter/app/lib/src/screens/counter/state.dart
new file mode 100644
index 0000000000..c5dc68a474
--- /dev/null
+++ b/Dart/multi_counter/app/lib/src/screens/counter/state.dart
@@ -0,0 +1,117 @@
+import 'dart:async';
+
+import 'package:cloud_firestore/cloud_firestore.dart';
+import 'package:cloud_functions/cloud_functions.dart';
+import 'package:firebase_auth/firebase_auth.dart';
+import 'package:flutter/foundation.dart';
+import 'package:multi_counter_shared/multi_counter_shared.dart';
+import 'package:stream_transform/stream_transform.dart';
+
+import '../../config_state.dart';
+
+typedef GlobalData = ({int totalUsers, int totalClicks});
+
+class CounterState {
+  CounterState() {
+    _incrementController.stream
+        .switchMap((_) => _callIncrement().asStream())
+        .listen(_handleIncrementResult);
+
+    _initFirestore();
+  }
+
+  final ValueNotifier<int> userCounter = ValueNotifier(0);
+  final ValueNotifier<GlobalData?> globalCounter = ValueNotifier(null);
+
+  final _incrementController = StreamController<void>.broadcast();
+  final _subscriptions = <StreamSubscription>[];
+  final _responseController = StreamController<IncrementResponse>.broadcast();
+
+  Stream<IncrementResponse> get incrementResponseStream =>
+      _responseController.stream;
+
+  // TODO: consider creating shared constants for collection and field names.
+  // ...and putting them in the shared package.
+  void _initFirestore() {
+    final uid = FirebaseAuth.instance.currentUser?.uid;
+    if (uid != null) {
+      _subscriptions.add(
+        FirebaseFirestore.instance
+            .collection(usersCollection)
+            .doc(uid)
+            .snapshots()
+            .listen((snapshot) {
+              if (snapshot.exists) {
+                final data = snapshot.data();
+                if (data != null && data.containsKey(countField)) {
+                  userCounter.value = data[countField] as int;
+                }
+              }
+            }),
+      );
+
+      _subscriptions.add(
+        FirebaseFirestore.instance
+            .collection(globalCollection)
+            .doc(varsDocument)
+            .snapshots()
+            .listen((snapshot) {
+              if (snapshot.data() case {
+                totalCountField: int totalClicks,
+                totalUsersField: int totalUsers,
+              }) {
+                globalCounter.value = (
+                  totalUsers: totalUsers,
+                  totalClicks: totalClicks,
+                );
+              }
+            }),
+      );
+    } else {
+      print('no uid');
+    }
+  }
+
+  // TODO: consider making this a nullable-property and disabling
+  // the button when we're waiting for the function to complete.
+  void increment() {
+    _incrementController.add(null);
+  }
+
+  Future<void> _callIncrement() async {
+    final user = FirebaseAuth.instance.currentUser;
+    if (user == null) {
+      _responseController.add(
+        IncrementResponse.failure('User is not authenticated.'),
+      );
+      return;
+    }
+
+    final idToken = await user.getIdToken();
+    if (idToken == null) {
+      _responseController.add(
+        IncrementResponse.failure('User is not authenticated.'),
+      );
+      return;
+    }
+
+    try {
+      await incrementHttpsCallable.call<void>();
+    } on FirebaseFunctionsException catch (e) {
+      print('Error calling increment: ${e.code} ${e.message}');
+      _responseController.add(IncrementResponse.failure('Error: ${e.code}'));
+    }
+  }
+
+  void _handleIncrementResult(_) {
+    // TODO: handle the result
+  }
+
+  void dispose() {
+    _responseController.close();
+    _incrementController.close();
+    for (final sub in _subscriptions) {
+      sub.cancel();
+    }
+  }
+}
diff --git a/Dart/multi_counter/app/lib/src/screens/login.dart b/Dart/multi_counter/app/lib/src/screens/login.dart
new file mode 100644
index 0000000000..66dc714073
--- /dev/null
+++ b/Dart/multi_counter/app/lib/src/screens/login.dart
@@ -0,0 +1,67 @@
+import 'package:firebase_auth/firebase_auth.dart';
+import 'package:flutter/foundation.dart';
+import 'package:flutter/material.dart';
+
+import '../constants.dart';
+import '../widgets/app_scaffold.dart';
+
+class LoginScreen extends StatelessWidget {
+  const LoginScreen({super.key});
+
+  Future<void> _signIn() async {
+    try {
+      final googleProvider = GoogleAuthProvider()..addScope('email');
+      if (kDebugMode) {
+        await FirebaseAuth.instance.signInWithPopup(googleProvider);
+      } else {
+        await FirebaseAuth.instance.signInWithRedirect(googleProvider);
+      }
+    } catch (e) {
+      print('Google sign in error: $e');
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) => AppScaffold(
+    useCardGradient: true,
+    child: SingleChildScrollView(
+      child: Column(
+        mainAxisSize: MainAxisSize.min,
+        mainAxisAlignment: MainAxisAlignment.center,
+        children: [
+          Text(
+            appTitle,
+            style: Theme.of(context).textTheme.headlineMedium,
+            textAlign: TextAlign.center,
+          ),
+          const SizedBox(height: 8),
+          Text(
+            'Sign in to continue',
+            style: Theme.of(context).textTheme.bodyMedium?.copyWith(
+              color: Theme.of(context).colorScheme.onSurfaceVariant,
+            ),
+            textAlign: TextAlign.center,
+          ),
+          const SizedBox(height: doubleSpaceSize),
+          SizedBox(
+            width: double.infinity,
+            child: ElevatedButton.icon(
+              onPressed: _signIn,
+              icon: const Icon(Icons.login),
+              label: const Text('Sign in with Google'),
+              style: ElevatedButton.styleFrom(
+                padding: const EdgeInsets.symmetric(vertical: spaceSize),
+                backgroundColor: Theme.of(context).colorScheme.primary,
+                foregroundColor: Theme.of(context).colorScheme.onPrimary,
+                elevation: 4,
+                shape: RoundedRectangleBorder(
+                  borderRadius: BorderRadius.circular(12),
+                ),
+              ),
+            ),
+          ),
+        ],
+      ),
+    ),
+  );
+}
diff --git a/Dart/multi_counter/app/lib/src/widgets/about_popup.dart b/Dart/multi_counter/app/lib/src/widgets/about_popup.dart
new file mode 100644
index 0000000000..4d4ab59795
--- /dev/null
+++ b/Dart/multi_counter/app/lib/src/widgets/about_popup.dart
@@ -0,0 +1,119 @@
+import 'package:flutter/gestures.dart';
+import 'package:flutter/material.dart';
+import 'package:url_launcher/url_launcher.dart';
+
+import '../constants.dart';
+
+class AboutPopup extends StatelessWidget {
+  const AboutPopup({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = Theme.of(context);
+    final colorScheme = theme.colorScheme;
+
+    return Dialog(
+      backgroundColor: Colors.transparent,
+      insetPadding: const EdgeInsets.all(spaceSize * 2),
+      child: ConstrainedBox(
+        constraints: const BoxConstraints(maxWidth: maxContentWidth),
+        child: Container(
+          padding: const EdgeInsets.all(doubleSpaceSize),
+          decoration: BoxDecoration(
+            color: colorScheme.surface,
+            borderRadius: BorderRadius.circular(28),
+            border: Border.all(color: colorScheme.outlineVariant),
+            boxShadow: [
+              BoxShadow(
+                color: Colors.black.withValues(alpha: 0.1),
+                blurRadius: 24,
+                offset: const Offset(0, 12),
+              ),
+            ],
+          ),
+          child: Column(
+            mainAxisSize: MainAxisSize.min,
+            crossAxisAlignment: CrossAxisAlignment.stretch,
+            children: [
+              Row(
+                children: [
+                  Icon(
+                    Icons.info_outline,
+                    color: colorScheme.primary,
+                    size: 28,
+                  ),
+                  const SizedBox(width: spaceSize),
+                  Expanded(
+                    child: Text(
+                      'About $appTitle',
+                      style: theme.textTheme.headlineSmall?.copyWith(
+                        fontWeight: FontWeight.bold,
+                      ),
+                    ),
+                  ),
+                  IconButton(
+                    icon: const Icon(Icons.close),
+                    onPressed: () => Navigator.of(context).pop(),
+                    tooltip: 'Close',
+                  ),
+                ],
+              ),
+              const SizedBox(height: doubleSpaceSize),
+              Text(
+                'This is a demo application showcasing the '
+                'integration of Flutter, Firebase, and Dart.',
+                style: theme.textTheme.bodyMedium,
+              ),
+              const SizedBox(height: spaceSize),
+              Text.rich(
+                TextSpan(
+                  children: [
+                    const TextSpan(text: 'Source Code: '),
+                    TextSpan(
+                      text: githubDisplayUrl,
+                      style: TextStyle(
+                        color: colorScheme.primary,
+                        decoration: TextDecoration.underline,
+                      ),
+                      recognizer: TapGestureRecognizer()
+                        ..onTap = () => launchUrl(githubUri),
+                    ),
+                  ],
+                ),
+                style: theme.textTheme.bodyMedium,
+              ),
+              const SizedBox(height: doubleSpaceSize),
+              Container(
+                padding: const EdgeInsets.all(spaceSize),
+                decoration: BoxDecoration(
+                  color: colorScheme.surfaceContainerHighest.withValues(
+                    alpha: 0.5,
+                  ),
+                  borderRadius: BorderRadius.circular(16),
+                ),
+                child: Row(
+                  children: [
+                    Icon(
+                      Icons.privacy_tip_outlined,
+                      color: colorScheme.secondary,
+                    ),
+                    const SizedBox(width: spaceSize),
+                    Expanded(
+                      child: Text(
+                        "Privacy: I won't do anything weird with your email. "
+                        'Promise.',
+                        style: theme.textTheme.bodyMedium?.copyWith(
+                          color: colorScheme.onSurfaceVariant,
+                        ),
+                      ),
+                    ),
+                  ],
+                ),
+              ),
+            ],
+          ),
+        ),
+      ),
+    );
+  }
+}
diff --git a/Dart/multi_counter/app/lib/src/widgets/app_scaffold.dart b/Dart/multi_counter/app/lib/src/widgets/app_scaffold.dart
new file mode 100644
index 0000000000..a4a1ec44c1
--- /dev/null
+++ b/Dart/multi_counter/app/lib/src/widgets/app_scaffold.dart
@@ -0,0 +1,125 @@
+import 'package:firebase_auth/firebase_auth.dart';
+import 'package:flutter/material.dart';
+
+import '../constants.dart';
+import 'about_popup.dart';
+import 'centered_premium_card.dart';
+
+class AppScaffold extends StatelessWidget {
+  final Widget child;
+  final String? title;
+  final bool useCardGradient;
+
+  const AppScaffold({
+    super.key,
+    required this.child,
+    this.title,
+    this.useCardGradient = false,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    final user = FirebaseAuth.instance.currentUser;
+    final size = MediaQuery.of(context).size;
+    final isSmall = size.width < 370 || size.height < 650;
+
+    if (isSmall) {
+      return _buildSmallLayout(context, user);
+    }
+
+    return _buildLargeLayout(context, user);
+  }
+
+  Widget _buildSmallLayout(BuildContext context, User? user) => Scaffold(
+    body: SafeArea(
+      child: SingleChildScrollView(
+        child: Padding(
+          padding: const EdgeInsets.symmetric(
+            vertical: spaceSize / 2,
+            horizontal: spaceSize / 2,
+          ),
+          child: Column(
+            crossAxisAlignment: CrossAxisAlignment.stretch,
+            children: [
+              // Content
+              child,
+
+              const SizedBox(height: doubleSpaceSize),
+
+              // About
+              TextButton.icon(
+                onPressed: () => showDialog<void>(
+                  context: context,
+                  builder: (context) => const AboutPopup(),
+                ),
+                icon: const Icon(Icons.info_outline),
+                label: const Text('About'),
+              ),
+
+              // User info
+              if (user != null) ...[
+                const SizedBox(height: spaceSize),
+                Text(
+                  user.email ?? '',
+                  style: Theme.of(context).textTheme.bodyMedium,
+                  textAlign: TextAlign.center,
+                ),
+                const SizedBox(height: spaceSize / 2),
+                IconButton(
+                  icon: const Icon(Icons.logout),
+                  onPressed: () => FirebaseAuth.instance.signOut(),
+                ),
+              ],
+            ],
+          ),
+        ),
+      ),
+    ),
+  );
+
+  Widget _buildLargeLayout(BuildContext context, User? user) => Scaffold(
+    body: CenteredPremiumCard(useGradient: useCardGradient, child: child),
+    bottomNavigationBar: SafeArea(
+      child: Padding(
+        padding: const EdgeInsets.symmetric(
+          horizontal: spaceSize,
+          vertical: spaceSize / 2,
+        ),
+        child: Column(
+          mainAxisSize: MainAxisSize.min,
+          children: [
+            Row(
+              mainAxisAlignment: MainAxisAlignment.center,
+              children: [
+                TextButton.icon(
+                  onPressed: () => showDialog<void>(
+                    context: context,
+                    builder: (context) => const AboutPopup(),
+                  ),
+                  icon: const Icon(Icons.info_outline),
+                  label: const Text('About'),
+                ),
+                if (user != null) ...[
+                  const SizedBox(width: spaceSize),
+                  Expanded(
+                    child: Text(
+                      user.email ?? '',
+                      style: Theme.of(context).textTheme.bodyMedium,
+                      overflow: TextOverflow.ellipsis,
+                      textAlign: TextAlign.end,
+                    ),
+                  ),
+                  const SizedBox(width: spaceSize / 2),
+                  IconButton(
+                    icon: const Icon(Icons.logout),
+                    onPressed: () => FirebaseAuth.instance.signOut(),
+                  ),
+                ],
+              ],
+            ),
+          ],
+        ),
+      ),
+    ),
+  );
+}
diff --git a/Dart/multi_counter/app/lib/src/widgets/centered_premium_card.dart b/Dart/multi_counter/app/lib/src/widgets/centered_premium_card.dart
new file mode 100644
index 0000000000..4b67360fe7
--- /dev/null
+++ b/Dart/multi_counter/app/lib/src/widgets/centered_premium_card.dart
@@ -0,0 +1,60 @@
+import 'package:flutter/material.dart';
+
+import '../constants.dart';
+
+class CenteredPremiumCard extends StatelessWidget {
+  final Widget child;
+  final bool useGradient;
+  final EdgeInsetsGeometry padding;
+  final double? maxWidth;
+
+  const CenteredPremiumCard({
+    super.key,
+    required this.child,
+    this.useGradient = false,
+    this.padding = const EdgeInsets.all(doubleSpaceSize),
+    this.maxWidth,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = Theme.of(context);
+    final colorScheme = theme.colorScheme;
+
+    return Center(
+      child: Padding(
+        padding: const EdgeInsets.all(spaceSize),
+        child: ConstrainedBox(
+          constraints: BoxConstraints(maxWidth: maxWidth ?? maxContentWidth),
+          child: Container(
+            decoration: BoxDecoration(
+              color: useGradient ? null : colorScheme.surface,
+              gradient: useGradient
+                  ? LinearGradient(
+                      begin: Alignment.topLeft,
+                      end: Alignment.bottomRight,
+                      colors: [
+                        colorScheme.surface,
+                        colorScheme.surfaceContainerHighest.withValues(
+                          alpha: 0.5,
+                        ),
+                      ],
+                    )
+                  : null,
+              borderRadius: BorderRadius.circular(24),
+              boxShadow: [
+                BoxShadow(
+                  color: Colors.black.withValues(alpha: 0.05),
+                  blurRadius: 20,
+                  offset: const Offset(0, 10),
+                ),
+              ],
+              border: Border.all(color: colorScheme.outlineVariant),
+            ),
+            child: Padding(padding: padding, child: child),
+          ),
+        ),
+      ),
+    );
+  }
+}
diff --git a/Dart/multi_counter/app/pubspec.yaml b/Dart/multi_counter/app/pubspec.yaml
new file mode 100644
index 0000000000..cc5746962c
--- /dev/null
+++ b/Dart/multi_counter/app/pubspec.yaml
@@ -0,0 +1,30 @@
+name: multi_counter_app
+publish_to: 'none'
+
+version: 1.0.0+1
+resolution: workspace
+
+environment:
+  sdk: ^3.10.0
+
+dependencies:
+  cloud_firestore: ^6.1.2
+  cloud_functions: ^6.0.0
+  firebase_auth: ^6.1.4
+  firebase_core: ^4.4.0
+  flutter:
+    sdk: flutter
+  go_router: ^17.0.1
+  google_sign_in: any
+  http: ^1.6.0
+  multi_counter_shared: any
+  stream_transform: ^2.1.1
+  url_launcher: ^6.3.2
+
+dev_dependencies:
+  build_runner: 
+  flutter_test:
+    sdk: flutter
+
+flutter:
+  uses-material-design: true
diff --git a/Dart/multi_counter/app/web/favicon.png b/Dart/multi_counter/app/web/favicon.png
new file mode 100644
index 0000000000..8aaa46ac1a
Binary files /dev/null and b/Dart/multi_counter/app/web/favicon.png differ
diff --git a/Dart/multi_counter/app/web/icons/Icon-192.png b/Dart/multi_counter/app/web/icons/Icon-192.png
new file mode 100644
index 0000000000..b749bfef07
Binary files /dev/null and b/Dart/multi_counter/app/web/icons/Icon-192.png differ
diff --git a/Dart/multi_counter/app/web/icons/Icon-512.png b/Dart/multi_counter/app/web/icons/Icon-512.png
new file mode 100644
index 0000000000..88cfd48dff
Binary files /dev/null and b/Dart/multi_counter/app/web/icons/Icon-512.png differ
diff --git a/Dart/multi_counter/app/web/icons/Icon-maskable-192.png b/Dart/multi_counter/app/web/icons/Icon-maskable-192.png
new file mode 100644
index 0000000000..eb9b4d76e5
Binary files /dev/null and b/Dart/multi_counter/app/web/icons/Icon-maskable-192.png differ
diff --git a/Dart/multi_counter/app/web/icons/Icon-maskable-512.png b/Dart/multi_counter/app/web/icons/Icon-maskable-512.png
new file mode 100644
index 0000000000..d69c56691f
Binary files /dev/null and b/Dart/multi_counter/app/web/icons/Icon-maskable-512.png differ
diff --git a/Dart/multi_counter/app/web/index.html b/Dart/multi_counter/app/web/index.html
new file mode 100644
index 0000000000..03232de553
--- /dev/null
+++ b/Dart/multi_counter/app/web/index.html
@@ -0,0 +1,24 @@
+<!DOCTYPE html>
+<html>
+<head>
+  <base href="$FLUTTER_BASE_HREF">
+
+  <meta charset="UTF-8">
+  <meta content="IE=Edge" http-equiv="X-UA-Compatible">
+  <meta name="description" content="A Firebase, Flutter, and Dart demo.">
+
+  <!-- iOS meta tags & icons -->
+  <meta name="mobile-web-app-capable" content="yes">
+  <meta name="apple-mobile-web-app-status-bar-style" content="black">
+  <meta name="apple-mobile-web-app-title" content="app">
+  <link rel="apple-touch-icon" href="icons/Icon-192.png">
+
+  <!-- Favicon -->
+  <link rel="icon" type="image/png" href="favicon.png"/>
+
+  <title>Multi-counter!</title>
+</head>
+<body>
+  <script src="flutter_bootstrap.js" async></script>
+</body>
+</html>
diff --git a/Dart/multi_counter/firebase.json b/Dart/multi_counter/firebase.json
new file mode 100644
index 0000000000..ccc9fe0522
--- /dev/null
+++ b/Dart/multi_counter/firebase.json
@@ -0,0 +1,71 @@
+{
+  "firestore": {
+    "rules": "server/firestore.rules"
+  },
+  "functions": [
+    {
+      "source": "server",
+      "codebase": "default",
+      "runtime": "dart3"
+    }
+  ],
+  "hosting": {
+    "predeploy": "cd app && flutter build web --wasm --no-strip-wasm --source-maps",
+    "public": "app/build/web",
+    "ignore": [
+      "firebase.json",
+      "**/.*"
+    ],
+    "rewrites": [
+      {
+        "source": "**",
+        "destination": "/index.html"
+      }
+    ],
+    "headers": [
+      {
+        "source": "**",
+        "headers": [
+          {
+            "key": "Cross-Origin-Opener-Policy",
+            "value": "same-origin-allow-popups"
+          }
+        ]
+      }
+    ]
+  },
+  "emulators": {
+    "functions": {
+      "port": 5001
+    },
+    "auth": {
+      "port": 9099
+    },
+    "pubsub": {
+      "port": 8085
+    },
+    "firestore": {
+      "port": 8080
+    },
+    "database": {
+      "port": 9000
+    },
+    "ui": {
+      "enabled": true,
+      "port": 4000
+    },
+    "singleProjectMode": true
+  },
+  "flutter": {
+    "platforms": {
+      "dart": {
+        "app/lib/firebase_options.dart": {
+          "projectId": "n26-full-stack-dart",
+          "configurations": {
+            "web": "1:138342796561:web:22e80ba7c9119d66d950b0"
+          }
+        }
+      }
+    }
+  }
+}
diff --git a/Dart/multi_counter/pubspec.lock b/Dart/multi_counter/pubspec.lock
new file mode 100644
index 0000000000..6a0e7e7184
--- /dev/null
+++ b/Dart/multi_counter/pubspec.lock
@@ -0,0 +1,930 @@
+# Generated by pub
+# See https://dart.dev/tools/pub/glossary#lockfile
+packages:
+  _discoveryapis_commons:
+    dependency: transitive
+    description:
+      name: _discoveryapis_commons
+      sha256: "113c4100b90a5b70a983541782431b82168b3cae166ab130649c36eb3559d498"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.0.7"
+  _fe_analyzer_shared:
+    dependency: transitive
+    description:
+      name: _fe_analyzer_shared
+      sha256: "8d7ff3948166b8ec5da0fbb5962000926b8e02f2ed9b3e51d1738905fbd4c98d"
+      url: "https://pub.dev"
+    source: hosted
+    version: "93.0.0"
+  _flutterfire_internals:
+    dependency: transitive
+    description:
+      name: _flutterfire_internals
+      sha256: bda3b7b55958bfd867addc40d067b4b11f7b8846d57671f5b5a6e7f9a56fe3ad
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.3.69"
+  analyzer:
+    dependency: transitive
+    description:
+      name: analyzer
+      sha256: de7148ed2fcec579b19f122c1800933dfa028f6d9fd38a152b04b1516cec120b
+      url: "https://pub.dev"
+    source: hosted
+    version: "10.0.1"
+  args:
+    dependency: transitive
+    description:
+      name: args
+      sha256: d0481093c50b1da8910eb0bb301626d4d8eb7284aa739614d2b394ee09e3ea04
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.7.0"
+  asn1lib:
+    dependency: transitive
+    description:
+      name: asn1lib
+      sha256: "9a8f69025044eb466b9b60ef3bc3ac99b4dc6c158ae9c56d25eeccf5bc56d024"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.6.5"
+  async:
+    dependency: transitive
+    description:
+      name: async
+      sha256: e2eb0491ba5ddb6177742d2da23904574082139b07c1e33b8503b9f46f3e1a37
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.13.1"
+  boolean_selector:
+    dependency: transitive
+    description:
+      name: boolean_selector
+      sha256: "8aab1771e1243a5063b8b0ff68042d67334e3feab9e95b9490f9a6ebf73b42ea"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.1.2"
+  build:
+    dependency: transitive
+    description:
+      name: build
+      sha256: aadd943f4f8cc946882c954c187e6115a84c98c81ad1d9c6cbf0895a8c85da9c
+      url: "https://pub.dev"
+    source: hosted
+    version: "4.0.5"
+  build_config:
+    dependency: transitive
+    description:
+      name: build_config
+      sha256: "4070d2a59f8eec34c97c86ceb44403834899075f66e8a9d59706f8e7834f6f71"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.3.0"
+  build_daemon:
+    dependency: transitive
+    description:
+      name: build_daemon
+      sha256: bf05f6e12cfea92d3c09308d7bcdab1906cd8a179b023269eed00c071004b957
+      url: "https://pub.dev"
+    source: hosted
+    version: "4.1.1"
+  build_runner:
+    dependency: transitive
+    description:
+      name: build_runner
+      sha256: "521daf8d189deb79ba474e43a696b41c49fb3987818dbacf3308f1e03673a75e"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.13.1"
+  built_collection:
+    dependency: transitive
+    description:
+      name: built_collection
+      sha256: "376e3dd27b51ea877c28d525560790aee2e6fbb5f20e2f85d5081027d94e2100"
+      url: "https://pub.dev"
+    source: hosted
+    version: "5.1.1"
+  built_value:
+    dependency: transitive
+    description:
+      name: built_value
+      sha256: "0730c18c770d05636a8f945c32a4d7d81cb6e0f0148c8db4ad12e7748f7e49af"
+      url: "https://pub.dev"
+    source: hosted
+    version: "8.12.5"
+  characters:
+    dependency: transitive
+    description:
+      name: characters
+      sha256: faf38497bda5ead2a8c7615f4f7939df04333478bf32e4173fcb06d428b5716b
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.4.1"
+  checked_yaml:
+    dependency: transitive
+    description:
+      name: checked_yaml
+      sha256: "959525d3162f249993882720d52b7e0c833978df229be20702b33d48d91de70f"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.0.4"
+  clock:
+    dependency: transitive
+    description:
+      name: clock
+      sha256: fddb70d9b5277016c77a80201021d40a2247104d9f4aa7bab7157b7e3f05b84b
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.1.2"
+  cloud_firestore:
+    dependency: transitive
+    description:
+      name: cloud_firestore
+      sha256: "3ac242332166ae5037bd87bc343744bb96d88d7b13f791492b00958ce5cc6c63"
+      url: "https://pub.dev"
+    source: hosted
+    version: "6.3.0"
+  cloud_firestore_platform_interface:
+    dependency: transitive
+    description:
+      name: cloud_firestore_platform_interface
+      sha256: "1bd08b736e1015e8bf5448f5ef67b2087a2380c2c1c7972f8403c1c7b41f5359"
+      url: "https://pub.dev"
+    source: hosted
+    version: "7.2.0"
+  cloud_firestore_web:
+    dependency: transitive
+    description:
+      name: cloud_firestore_web
+      sha256: "18617275ffa2331d3ea058c515ef218bcce2ae13a14bee922563ca6ae2507c26"
+      url: "https://pub.dev"
+    source: hosted
+    version: "5.3.0"
+  cloud_functions:
+    dependency: transitive
+    description:
+      name: cloud_functions
+      sha256: "036aa4f3b880935bda48fd6ab516e0f11686c328a46313226b9cbad9220b4c59"
+      url: "https://pub.dev"
+    source: hosted
+    version: "6.2.0"
+  cloud_functions_platform_interface:
+    dependency: transitive
+    description:
+      name: cloud_functions_platform_interface
+      sha256: "2a52ee909011b0f33ae2074b7a431bc2d7fff4618948d93d5e71830688e0733f"
+      url: "https://pub.dev"
+    source: hosted
+    version: "5.8.12"
+  cloud_functions_web:
+    dependency: transitive
+    description:
+      name: cloud_functions_web
+      sha256: be032545ca1621248ffd251930952835593a9b8136895379930cecea766379a4
+      url: "https://pub.dev"
+    source: hosted
+    version: "5.1.5"
+  code_builder:
+    dependency: transitive
+    description:
+      name: code_builder
+      sha256: "6a6cab2ba4680d6423f34a9b972a4c9a94ebe1b62ecec4e1a1f2cba91fd1319d"
+      url: "https://pub.dev"
+    source: hosted
+    version: "4.11.1"
+  collection:
+    dependency: transitive
+    description:
+      name: collection
+      sha256: "2f5709ae4d3d59dd8f7cd309b4e023046b57d8a6c82130785d2b0e5868084e76"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.19.1"
+  convert:
+    dependency: transitive
+    description:
+      name: convert
+      sha256: b30acd5944035672bc15c6b7a8b47d773e41e2f17de064350988c5d02adb1c68
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.1.2"
+  crypto:
+    dependency: transitive
+    description:
+      name: crypto
+      sha256: c8ea0233063ba03258fbcf2ca4d6dadfefe14f02fab57702265467a19f27fadf
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.0.7"
+  dart_flutter_team_lints:
+    dependency: "direct dev"
+    description:
+      name: dart_flutter_team_lints
+      sha256: ce0f23e2cf95cbd21766d17a7cf88584758b67fd77338d61f2ce77e3cf6d763c
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.5.2"
+  dart_jsonwebtoken:
+    dependency: transitive
+    description:
+      name: dart_jsonwebtoken
+      sha256: cb79ed79baa02b4f59a597bf365873cbd83f9bb15273d63f7803802d21717c7d
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.4.0"
+  dart_style:
+    dependency: transitive
+    description:
+      name: dart_style
+      sha256: "29f7ecc274a86d32920b1d9cfc7502fa87220da41ec60b55f329559d5732e2b2"
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.1.7"
+  equatable:
+    dependency: transitive
+    description:
+      name: equatable
+      sha256: "3e0141505477fd8ad55d6eb4e7776d3fe8430be8e497ccb1521370c3f21a3e2b"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.0.8"
+  fake_async:
+    dependency: transitive
+    description:
+      name: fake_async
+      sha256: "5368f224a74523e8d2e7399ea1638b37aecfca824a3cc4dfdf77bf1fa905ac44"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.3.3"
+  ffi:
+    dependency: transitive
+    description:
+      name: ffi
+      sha256: "6d7fd89431262d8f3125e81b50d3847a091d846eafcd4fdb88dd06f36d705a45"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.2.0"
+  file:
+    dependency: transitive
+    description:
+      name: file
+      sha256: a3b4f84adafef897088c160faf7dfffb7696046cb13ae90b508c2cbc95d3b8d4
+      url: "https://pub.dev"
+    source: hosted
+    version: "7.0.1"
+  firebase_admin_sdk:
+    dependency: transitive
+    description:
+      name: firebase_admin_sdk
+      sha256: "3827a3b30f3e76e9502cafab6fb6be28b29c632e83475b6ce3f146b5e077baad"
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.5.1"
+  firebase_auth:
+    dependency: transitive
+    description:
+      name: firebase_auth
+      sha256: b12cb1e2e87797d27e0041100b73ebf890dbafcff2e7e991d4593f5e8e309808
+      url: "https://pub.dev"
+    source: hosted
+    version: "6.4.0"
+  firebase_auth_platform_interface:
+    dependency: transitive
+    description:
+      name: firebase_auth_platform_interface
+      sha256: c71517b3c78480be42789b05316a7692d69296c17848bd6a9e798300abae1ec7
+      url: "https://pub.dev"
+    source: hosted
+    version: "8.1.9"
+  firebase_auth_web:
+    dependency: transitive
+    description:
+      name: firebase_auth_web
+      sha256: "52b0224eb46b09f387e99710707be2d3f48da67c74fe14202e4b942cbe8ce9fd"
+      url: "https://pub.dev"
+    source: hosted
+    version: "6.1.5"
+  firebase_core:
+    dependency: transitive
+    description:
+      name: firebase_core
+      sha256: d5a94b884dcb1e6d3430298e94bfe002238094cdfd5e29202d536ee2120f9158
+      url: "https://pub.dev"
+    source: hosted
+    version: "4.7.0"
+  firebase_core_platform_interface:
+    dependency: transitive
+    description:
+      name: firebase_core_platform_interface
+      sha256: "0ecda14c1bfc9ed8cac303dd0f8d04a320811b479362a9a4efb14fd331a473ce"
+      url: "https://pub.dev"
+    source: hosted
+    version: "6.0.3"
+  firebase_core_web:
+    dependency: transitive
+    description:
+      name: firebase_core_web
+      sha256: dc5096257cd67292d34d78ceeb90836f02a4be921b5f3934311a02bb2376118c
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.6.0"
+  firebase_functions:
+    dependency: transitive
+    description:
+      name: firebase_functions
+      sha256: c4e9cdcf8a5650223b20992be52517981f277c4e6d9a17c1077c9523a4d65e8f
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.5.1"
+  fixnum:
+    dependency: transitive
+    description:
+      name: fixnum
+      sha256: b6dc7065e46c974bc7c5f143080a6764ec7a4be6da1285ececdc37be96de53be
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.1.1"
+  flutter:
+    dependency: transitive
+    description: flutter
+    source: sdk
+    version: "0.0.0"
+  flutter_test:
+    dependency: transitive
+    description: flutter
+    source: sdk
+    version: "0.0.0"
+  flutter_web_plugins:
+    dependency: transitive
+    description: flutter
+    source: sdk
+    version: "0.0.0"
+  glob:
+    dependency: transitive
+    description:
+      name: glob
+      sha256: c3f1ee72c96f8f78935e18aa8cecced9ab132419e8625dc187e1c2408efc20de
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.1.3"
+  go_router:
+    dependency: transitive
+    description:
+      name: go_router
+      sha256: "5540e4a3f416dd4a93458257b908eb88353cbd0fb5b0a3d1bd7d849ba1e88735"
+      url: "https://pub.dev"
+    source: hosted
+    version: "17.2.1"
+  google_cloud:
+    dependency: transitive
+    description:
+      name: google_cloud
+      sha256: fbcde933b2d8600c3cdb2328f8f4c47628ec29a39e9cef85dee535c7868993c4
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.4.1"
+  google_cloud_firestore:
+    dependency: transitive
+    description:
+      name: google_cloud_firestore
+      sha256: e9a788301ee25cef6ffa86046cb0e80b4974b4a72d23a25231e161587fd84c8c
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.5.1"
+  google_cloud_protobuf:
+    dependency: transitive
+    description:
+      name: google_cloud_protobuf
+      sha256: "5564bfba335f7ca82fcc865f6f2c04b11fd175ec23cb0248f6e22579017e03d1"
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.5.0"
+  google_cloud_rpc:
+    dependency: transitive
+    description:
+      name: google_cloud_rpc
+      sha256: "7eef0b8a77021d19aff96cefcb9356dde4187daac3ecec33d7017637b83cdb4d"
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.5.0"
+  google_cloud_storage:
+    dependency: transitive
+    description:
+      name: google_cloud_storage
+      sha256: "8410cddc2c37b7ef81d154b3533a7d8cf22a175f519fe9ba4ee0d5a790ea3040"
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.6.1"
+  google_identity_services_web:
+    dependency: transitive
+    description:
+      name: google_identity_services_web
+      sha256: "5d187c46dc59e02646e10fe82665fc3884a9b71bc1c90c2b8b749316d33ee454"
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.3.3+1"
+  google_sign_in:
+    dependency: transitive
+    description:
+      name: google_sign_in
+      sha256: "521031b65853b4409b8213c0387d57edaad7e2a949ce6dea0d8b2afc9cb29763"
+      url: "https://pub.dev"
+    source: hosted
+    version: "7.2.0"
+  google_sign_in_android:
+    dependency: transitive
+    description:
+      name: google_sign_in_android
+      sha256: be0d0733a6a7c5da165879d844a239aa87587a3c767a9163faedde581f731f76
+      url: "https://pub.dev"
+    source: hosted
+    version: "7.2.10"
+  google_sign_in_ios:
+    dependency: transitive
+    description:
+      name: google_sign_in_ios
+      sha256: ac1e4c1205267cb7999d1d81333fccffdfda29e853f434bbaf71525498bb6950
+      url: "https://pub.dev"
+    source: hosted
+    version: "6.3.0"
+  google_sign_in_platform_interface:
+    dependency: transitive
+    description:
+      name: google_sign_in_platform_interface
+      sha256: "7f59208c42b415a3cca203571128d6f84f885fead2d5b53eb65a9e27f2965bb5"
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.1.0"
+  google_sign_in_web:
+    dependency: transitive
+    description:
+      name: google_sign_in_web
+      sha256: d473003eeca892f96a01a64fc803378be765071cb0c265ee872c7f8683245d14
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.1.3"
+  googleapis:
+    dependency: transitive
+    description:
+      name: googleapis
+      sha256: "62b5988f228b774448ebd99b53fe8069becb55840f1b28948bb84160373dc0b6"
+      url: "https://pub.dev"
+    source: hosted
+    version: "16.0.0"
+  googleapis_auth:
+    dependency: transitive
+    description:
+      name: googleapis_auth
+      sha256: "661738b763d3e524de69df53bf4e03943e4e01e98265cebcc6684871b06a5379"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.3.0"
+  graphs:
+    dependency: transitive
+    description:
+      name: graphs
+      sha256: "741bbf84165310a68ff28fe9e727332eef1407342fca52759cb21ad8177bb8d0"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.3.2"
+  http:
+    dependency: transitive
+    description:
+      name: http
+      sha256: "87721a4a50b19c7f1d49001e51409bddc46303966ce89a65af4f4e6004896412"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.6.0"
+  http_multi_server:
+    dependency: transitive
+    description:
+      name: http_multi_server
+      sha256: aa6199f908078bb1c5efb8d8638d4ae191aac11b311132c3ef48ce352fb52ef8
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.2.2"
+  http_parser:
+    dependency: transitive
+    description:
+      name: http_parser
+      sha256: "178d74305e7866013777bab2c3d8726205dc5a4dd935297175b19a23a2e66571"
+      url: "https://pub.dev"
+    source: hosted
+    version: "4.1.2"
+  intl:
+    dependency: transitive
+    description:
+      name: intl
+      sha256: "3df61194eb431efc39c4ceba583b95633a403f46c9fd341e550ce0bfa50e9aa5"
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.20.2"
+  io:
+    dependency: transitive
+    description:
+      name: io
+      sha256: dfd5a80599cf0165756e3181807ed3e77daf6dd4137caaad72d0b7931597650b
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.0.5"
+  json_annotation:
+    dependency: transitive
+    description:
+      name: json_annotation
+      sha256: cb09e7dac6210041fad964ed7fbee004f14258b4eca4040f72d1234062ace4c8
+      url: "https://pub.dev"
+    source: hosted
+    version: "4.11.0"
+  json_serializable:
+    dependency: transitive
+    description:
+      name: json_serializable
+      sha256: fbcf404b03520e6e795f6b9b39badb2b788407dfc0a50cf39158a6ae1ca78925
+      url: "https://pub.dev"
+    source: hosted
+    version: "6.13.1"
+  leak_tracker:
+    dependency: transitive
+    description:
+      name: leak_tracker
+      sha256: "33e2e26bdd85a0112ec15400c8cbffea70d0f9c3407491f672a2fad47915e2de"
+      url: "https://pub.dev"
+    source: hosted
+    version: "11.0.2"
+  leak_tracker_flutter_testing:
+    dependency: transitive
+    description:
+      name: leak_tracker_flutter_testing
+      sha256: "1dbc140bb5a23c75ea9c4811222756104fbcd1a27173f0c34ca01e16bea473c1"
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.0.10"
+  leak_tracker_testing:
+    dependency: transitive
+    description:
+      name: leak_tracker_testing
+      sha256: "8d5a2d49f4a66b49744b23b018848400d23e54caf9463f4eb20df3eb8acb2eb1"
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.0.2"
+  lints:
+    dependency: transitive
+    description:
+      name: lints
+      sha256: "12f842a479589fea194fe5c5a3095abc7be0c1f2ddfa9a0e76aed1dbd26a87df"
+      url: "https://pub.dev"
+    source: hosted
+    version: "6.1.0"
+  logging:
+    dependency: transitive
+    description:
+      name: logging
+      sha256: c8245ada5f1717ed44271ed1c26b8ce85ca3228fd2ffdb75468ab01979309d61
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.3.0"
+  matcher:
+    dependency: transitive
+    description:
+      name: matcher
+      sha256: dc0b7dc7651697ea4ff3e69ef44b0407ea32c487a39fff6a4004fa585e901861
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.12.19"
+  material_color_utilities:
+    dependency: transitive
+    description:
+      name: material_color_utilities
+      sha256: "9c337007e82b1889149c82ed242ed1cb24a66044e30979c44912381e9be4c48b"
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.13.0"
+  meta:
+    dependency: transitive
+    description:
+      name: meta
+      sha256: "23f08335362185a5ea2ad3a4e597f1375e78bce8a040df5c600c8d3552ef2394"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.17.0"
+  mime:
+    dependency: transitive
+    description:
+      name: mime
+      sha256: "41a20518f0cb1256669420fdba0cd90d21561e560ac240f26ef8322e45bb7ed6"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.0.0"
+  package_config:
+    dependency: transitive
+    description:
+      name: package_config
+      sha256: f096c55ebb7deb7e384101542bfba8c52696c1b56fca2eb62827989ef2353bbc
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.2.0"
+  path:
+    dependency: transitive
+    description:
+      name: path
+      sha256: "75cca69d1490965be98c73ceaea117e8a04dd21217b37b292c9ddbec0d955bc5"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.9.1"
+  pem:
+    dependency: transitive
+    description:
+      name: pem
+      sha256: e66b389cbb007fa5860d511f08ea604ea68e78afc4e1b543dc227a0f0ef4faf9
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.0.6"
+  petitparser:
+    dependency: transitive
+    description:
+      name: petitparser
+      sha256: "91bd59303e9f769f108f8df05e371341b15d59e995e6806aefab827b58336675"
+      url: "https://pub.dev"
+    source: hosted
+    version: "7.0.2"
+  plugin_platform_interface:
+    dependency: transitive
+    description:
+      name: plugin_platform_interface
+      sha256: "4820fbfdb9478b1ebae27888254d445073732dae3d6ea81f0b7e06d5dedc3f02"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.1.8"
+  pointycastle:
+    dependency: transitive
+    description:
+      name: pointycastle
+      sha256: "92aa3841d083cc4b0f4709b5c74fd6409a3e6ba833ffc7dc6a8fee096366acf5"
+      url: "https://pub.dev"
+    source: hosted
+    version: "4.0.0"
+  pool:
+    dependency: transitive
+    description:
+      name: pool
+      sha256: "978783255c543aa3586a1b3c21f6e9d720eb315376a915872c61ef8b5c20177d"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.5.2"
+  protobuf:
+    dependency: transitive
+    description:
+      name: protobuf
+      sha256: "75ec242d22e950bdcc79ee38dd520ce4ee0bc491d7fadc4ea47694604d22bf06"
+      url: "https://pub.dev"
+    source: hosted
+    version: "6.0.0"
+  pub_semver:
+    dependency: transitive
+    description:
+      name: pub_semver
+      sha256: "5bfcf68ca79ef689f8990d1160781b4bad40a3bd5e5218ad4076ddb7f4081585"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.2.0"
+  pubspec_parse:
+    dependency: transitive
+    description:
+      name: pubspec_parse
+      sha256: "0560ba233314abbed0a48a2956f7f022cce7c3e1e73df540277da7544cad4082"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.5.0"
+  shelf:
+    dependency: transitive
+    description:
+      name: shelf
+      sha256: e7dd780a7ffb623c57850b33f43309312fc863fb6aa3d276a754bb299839ef12
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.4.2"
+  shelf_web_socket:
+    dependency: transitive
+    description:
+      name: shelf_web_socket
+      sha256: "3632775c8e90d6c9712f883e633716432a27758216dfb61bd86a8321c0580925"
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.0.0"
+  sky_engine:
+    dependency: transitive
+    description: flutter
+    source: sdk
+    version: "0.0.0"
+  source_gen:
+    dependency: transitive
+    description:
+      name: source_gen
+      sha256: "732792cfd197d2161a65bb029606a46e0a18ff30ef9e141a7a82172b05ea8ecd"
+      url: "https://pub.dev"
+    source: hosted
+    version: "4.2.2"
+  source_helper:
+    dependency: transitive
+    description:
+      name: source_helper
+      sha256: "1d3b229b2934034fb2e691fbb3d53e0f75a4af7b1407f88425ed8f209bcb1b8f"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.3.11"
+  source_span:
+    dependency: transitive
+    description:
+      name: source_span
+      sha256: "56a02f1f4cd1a2d96303c0144c93bd6d909eea6bee6bf5a0e0b685edbd4c47ab"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.10.2"
+  stack_trace:
+    dependency: transitive
+    description:
+      name: stack_trace
+      sha256: "8b27215b45d22309b5cddda1aa2b19bdfec9df0e765f2de506401c071d38d1b1"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.12.1"
+  stream_channel:
+    dependency: transitive
+    description:
+      name: stream_channel
+      sha256: "969e04c80b8bcdf826f8f16579c7b14d780458bd97f56d107d3950fdbeef059d"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.1.4"
+  stream_transform:
+    dependency: transitive
+    description:
+      name: stream_transform
+      sha256: ad47125e588cfd37a9a7f86c7d6356dde8dfe89d071d293f80ca9e9273a33871
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.1.1"
+  string_scanner:
+    dependency: transitive
+    description:
+      name: string_scanner
+      sha256: "921cd31725b72fe181906c6a94d987c78e3b98c2e205b397ea399d4054872b43"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.4.1"
+  term_glyph:
+    dependency: transitive
+    description:
+      name: term_glyph
+      sha256: "7f554798625ea768a7518313e58f83891c7f5024f88e46e7182a4558850a4b8e"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.2.2"
+  test_api:
+    dependency: transitive
+    description:
+      name: test_api
+      sha256: "8161c84903fd860b26bfdefb7963b3f0b68fee7adea0f59ef805ecca346f0c7a"
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.7.10"
+  typed_data:
+    dependency: transitive
+    description:
+      name: typed_data
+      sha256: f9049c039ebfeb4cf7a7104a675823cd72dba8297f264b6637062516699fa006
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.4.0"
+  url_launcher:
+    dependency: transitive
+    description:
+      name: url_launcher
+      sha256: f6a7e5c4835bb4e3026a04793a4199ca2d14c739ec378fdfe23fc8075d0439f8
+      url: "https://pub.dev"
+    source: hosted
+    version: "6.3.2"
+  url_launcher_android:
+    dependency: transitive
+    description:
+      name: url_launcher_android
+      sha256: "3bb000251e55d4a209aa0e2e563309dc9bb2befea2295fd0cec1f51760aac572"
+      url: "https://pub.dev"
+    source: hosted
+    version: "6.3.29"
+  url_launcher_ios:
+    dependency: transitive
+    description:
+      name: url_launcher_ios
+      sha256: "580fe5dfb51671ae38191d316e027f6b76272b026370708c2d898799750a02b0"
+      url: "https://pub.dev"
+    source: hosted
+    version: "6.4.1"
+  url_launcher_linux:
+    dependency: transitive
+    description:
+      name: url_launcher_linux
+      sha256: d5e14138b3bc193a0f63c10a53c94b91d399df0512b1f29b94a043db7482384a
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.2.2"
+  url_launcher_macos:
+    dependency: transitive
+    description:
+      name: url_launcher_macos
+      sha256: "368adf46f71ad3c21b8f06614adb38346f193f3a59ba8fe9a2fd74133070ba18"
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.2.5"
+  url_launcher_platform_interface:
+    dependency: transitive
+    description:
+      name: url_launcher_platform_interface
+      sha256: "552f8a1e663569be95a8190206a38187b531910283c3e982193e4f2733f01029"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.3.2"
+  url_launcher_web:
+    dependency: transitive
+    description:
+      name: url_launcher_web
+      sha256: d0412fcf4c6b31ecfdb7762359b7206ffba3bbffd396c6d9f9c4616ece476c1f
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.4.2"
+  url_launcher_windows:
+    dependency: transitive
+    description:
+      name: url_launcher_windows
+      sha256: "712c70ab1b99744ff066053cbe3e80c73332b38d46e5e945c98689b2e66fc15f"
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.1.5"
+  vector_math:
+    dependency: transitive
+    description:
+      name: vector_math
+      sha256: d530bd74fea330e6e364cda7a85019c434070188383e1cd8d9777ee586914c5b
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.2.0"
+  vm_service:
+    dependency: transitive
+    description:
+      name: vm_service
+      sha256: "046d3928e16fa4dc46e8350415661755ab759d9fc97fc21b5ab295f71e4f0499"
+      url: "https://pub.dev"
+    source: hosted
+    version: "15.1.0"
+  watcher:
+    dependency: transitive
+    description:
+      name: watcher
+      sha256: "1398c9f081a753f9226febe8900fce8f7d0a67163334e1c94a2438339d79d635"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.2.1"
+  web:
+    dependency: transitive
+    description:
+      name: web
+      sha256: "868d88a33d8a87b18ffc05f9f030ba328ffefba92d6c127917a2ba740f9cfe4a"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.1.1"
+  web_socket:
+    dependency: transitive
+    description:
+      name: web_socket
+      sha256: "34d64019aa8e36bf9842ac014bb5d2f5586ca73df5e4d9bf5c936975cae6982c"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.0.1"
+  web_socket_channel:
+    dependency: transitive
+    description:
+      name: web_socket_channel
+      sha256: d645757fb0f4773d602444000a8131ff5d48c9e47adfe9772652dd1a4f2d45c8
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.0.3"
+  yaml:
+    dependency: transitive
+    description:
+      name: yaml
+      sha256: b9da305ac7c39faa3f030eccd175340f968459dae4af175130b3fc47e40d76ce
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.1.3"
+  yaml_edit:
+    dependency: transitive
+    description:
+      name: yaml_edit
+      sha256: "07c9e63ba42519745182b88ca12264a7ba2484d8239958778dfe4d44fe760488"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.2.4"
+sdks:
+  dart: ">=3.10.0 <4.0.0"
+  flutter: ">=3.38.0"
diff --git a/Dart/multi_counter/pubspec.yaml b/Dart/multi_counter/pubspec.yaml
new file mode 100644
index 0000000000..c1ca6d2797
--- /dev/null
+++ b/Dart/multi_counter/pubspec.yaml
@@ -0,0 +1,12 @@
+name: _multi_counter_workspace
+
+environment:
+  sdk: ^3.10.0
+
+workspace:
+- app
+- server
+- shared
+
+dev_dependencies:
+  dart_flutter_team_lints: ^3.0.0
diff --git a/Dart/multi_counter/server/bin/server.dart b/Dart/multi_counter/server/bin/server.dart
new file mode 100644
index 0000000000..ca10d44a53
--- /dev/null
+++ b/Dart/multi_counter/server/bin/server.dart
@@ -0,0 +1,26 @@
+import 'package:firebase_functions/firebase_functions.dart';
+import 'package:multi_counter_server/src/storage_controller.dart';
+import 'package:multi_counter_shared/multi_counter_shared.dart';
+
+void main(List<String> args) async {
+  await fireUp(args, (firebase) async {
+    final storageController = StorageController(firebase.adminApp.firestore());
+
+    firebase.https.onCall(
+      name: incrementCallable,
+
+      options: const CallableOptions(
+        // TODO: should be explicit here about the supported hosts
+        cors: OptionLiteral(['*']),
+      ),
+      (request, response) async {
+        if (request.auth case AuthData auth?) {
+          await storageController.increment(auth.uid);
+          return CallableResult('success');
+        } else {
+          throw UnauthenticatedError();
+        }
+      },
+    );
+  });
+}
diff --git a/Dart/multi_counter/server/firestore.rules b/Dart/multi_counter/server/firestore.rules
new file mode 100644
index 0000000000..34b40a3088
--- /dev/null
+++ b/Dart/multi_counter/server/firestore.rules
@@ -0,0 +1,31 @@
+rules_version = '2';
+
+service cloud.firestore {
+  match /databases/{database}/documents {
+    // Rules for the 'users' collection
+    // Hierarchy: users (collection) -> {userId} (document) -> count (field)
+    match /users/{userId} {
+      // Users can only read their own document
+      allow read: if request.auth != null && request.auth.uid == userId;
+      
+      // Writes are handled by the backend (Cloud Functions) 
+      // which bypass these rules via service account privileges.
+      allow write: if false;
+    }
+
+    // Rules for the 'global' collection
+    // Hierarchy: global (collection) -> vars (document) -> totalCount, totalUsers (fields)
+    match /global/vars {
+      // Any authenticated user can read global stats
+      allow read: if request.auth != null;
+      
+      // Writes are handled by the backend
+      allow write: if false;
+    }
+    
+    // Default deny all for any other paths
+    match /{path=**} {
+      allow read, write: if false;
+    }
+  }
+}
diff --git a/Dart/multi_counter/server/lib/src/storage_controller.dart b/Dart/multi_counter/server/lib/src/storage_controller.dart
new file mode 100644
index 0000000000..f547ff6895
--- /dev/null
+++ b/Dart/multi_counter/server/lib/src/storage_controller.dart
@@ -0,0 +1,77 @@
+import 'package:google_cloud_firestore/google_cloud_firestore.dart';
+import 'package:multi_counter_shared/multi_counter_shared.dart';
+
+class StorageController {
+  final Firestore _firestore;
+
+  StorageController(this._firestore);
+
+  Future<void> increment(String userId) async {
+    try {
+      await _increment(userId);
+      await _updateGlobalCount();
+    } catch (e, stack) {
+      print('Error incrementing counter for user: $userId');
+      print(e);
+      print(stack);
+      rethrow;
+    }
+  }
+
+  Future<void> _increment(String userId) async {
+    await _firestore.runTransaction<void>((transaction) async {
+      final ref = _firestore.collection(usersCollection).doc(userId);
+
+      final snapshot = await transaction.get(ref);
+
+      if (!snapshot.exists) {
+        // Document doesn't exist, create it with count = 1
+        transaction.set(ref, _saveCount(1));
+      } else {
+        final data = snapshot.data();
+        if (data != null && data.containsKey(countField)) {
+          // Field exists, increment it
+          transaction.update(ref, {countField: const FieldValue.increment(1)});
+        } else {
+          // Field doesn't exist, initialize it to 1
+          transaction.update(ref, _saveCount(1));
+        }
+      }
+    });
+  }
+
+  Future<void> _updateGlobalCount() async {
+    final globalCountSnapshot = await _firestore
+        .collection(usersCollection)
+        .aggregate(const sum(countField), const count())
+        .get();
+
+    var globalCountRaw = globalCountSnapshot.getSum(countField);
+
+    if (globalCountRaw == null || globalCountRaw < 1) {
+      // TODO: we don't want to crash here, but we should log
+      print('Very weird value for global count: "$globalCountRaw');
+      globalCountRaw = 1;
+    }
+
+    final globalCountValue = globalCountRaw.toInt();
+    final userCountValue = globalCountSnapshot.count;
+
+    final globalVars = _firestore
+        .collection(globalCollection)
+        .doc(varsDocument);
+
+    // TODO: Investigate a more efficient way to do this
+    // Maybe with a trigger?
+    await globalVars.set({
+      totalCountField: globalCountValue,
+      totalUsersField: userCountValue,
+    });
+  }
+
+  Future<void> close() async {
+    await _firestore.terminate();
+  }
+}
+
+Map<String, dynamic> _saveCount(int count) => {countField: count};
diff --git a/Dart/multi_counter/server/pubspec.yaml b/Dart/multi_counter/server/pubspec.yaml
new file mode 100644
index 0000000000..985f5e37c8
--- /dev/null
+++ b/Dart/multi_counter/server/pubspec.yaml
@@ -0,0 +1,16 @@
+name: multi_counter_server
+publish_to: none
+resolution: workspace
+
+environment:
+  sdk: ^3.10.0
+
+dependencies:
+  firebase_admin_sdk: ^0.5.0
+  firebase_functions: ^0.5.0
+  google_cloud_firestore: ^0.5.0
+  multi_counter_shared: any # workspace
+
+dev_dependencies:
+  build_runner: ^2.4.0
+  http: ^1.2.2
diff --git a/Dart/multi_counter/shared/README.md b/Dart/multi_counter/shared/README.md
new file mode 100644
index 0000000000..5249489be0
--- /dev/null
+++ b/Dart/multi_counter/shared/README.md
@@ -0,0 +1,37 @@
+# Firestore layout
+
+```
+users/{userId}
+  count: Integer
+
+global/vars
+  totalCount: Integer
+```
+
+**TODO**: Put these in a shared Dart file to ensure they stay in sync with the code.
+
+
+
+## Security Rules
+
+
+**TODO**: Implement/deploy these rules!
+
+```
+rules_version = '2';
+service cloud.firestore {
+  match /databases/{database}/documents {
+    // Allow users to read/write their own data
+    match /users/{userId} {
+      allow read, write: if request.auth != null && request.auth.uid == userId;
+    }
+
+    // Allow authenticated users to only read global data
+    match /global/{docId} {
+      allow read: if request.auth != null;
+      allow write: if false;
+    }
+  }
+}
+```
+
diff --git a/Dart/multi_counter/shared/lib/multi_counter_shared.dart b/Dart/multi_counter/shared/lib/multi_counter_shared.dart
new file mode 100644
index 0000000000..551347e1a2
--- /dev/null
+++ b/Dart/multi_counter/shared/lib/multi_counter_shared.dart
@@ -0,0 +1,2 @@
+export 'src/constants.dart';
+export 'src/messages.dart';
diff --git a/Dart/multi_counter/shared/lib/src/constants.dart b/Dart/multi_counter/shared/lib/src/constants.dart
new file mode 100644
index 0000000000..9d6bb4aa06
--- /dev/null
+++ b/Dart/multi_counter/shared/lib/src/constants.dart
@@ -0,0 +1,17 @@
+/// Firestore constants for the `users` collection.
+///
+/// Hierarchy: `users` (collection) -> {userId} (document) -> `count` (field)
+const usersCollection = 'users';
+const countField = 'count';
+
+/// Firestore constants for the `global` collection.
+///
+/// Hierarchy: `global` (collection) -> `vars` (document) ->
+/// `totalCount`, `totalUsers` (fields)
+const globalCollection = 'global';
+const varsDocument = 'vars';
+const totalCountField = 'totalCount';
+const totalUsersField = 'totalUsers';
+
+/// HTTPS Callable function names.
+const incrementCallable = 'increment';
diff --git a/Dart/multi_counter/shared/lib/src/messages.dart b/Dart/multi_counter/shared/lib/src/messages.dart
new file mode 100644
index 0000000000..6011a30e7b
--- /dev/null
+++ b/Dart/multi_counter/shared/lib/src/messages.dart
@@ -0,0 +1,21 @@
+import 'package:json_annotation/json_annotation.dart';
+
+part 'messages.g.dart';
+
+@JsonSerializable()
+class IncrementResponse {
+  final bool success;
+  final String? message;
+
+  const IncrementResponse({required this.success, this.message});
+
+  factory IncrementResponse.success() => const IncrementResponse(success: true);
+
+  factory IncrementResponse.failure(String message) =>
+      IncrementResponse(success: false, message: message);
+
+  factory IncrementResponse.fromJson(Map<String, dynamic> json) =>
+      _$IncrementResponseFromJson(json);
+
+  Map<String, dynamic> toJson() => _$IncrementResponseToJson(this);
+}
diff --git a/Dart/multi_counter/shared/lib/src/messages.g.dart b/Dart/multi_counter/shared/lib/src/messages.g.dart
new file mode 100644
index 0000000000..4b9c46c922
--- /dev/null
+++ b/Dart/multi_counter/shared/lib/src/messages.g.dart
@@ -0,0 +1,16 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'messages.dart';
+
+// **************************************************************************
+// JsonSerializableGenerator
+// **************************************************************************
+
+IncrementResponse _$IncrementResponseFromJson(Map<String, dynamic> json) =>
+    IncrementResponse(
+      success: json['success'] as bool,
+      message: json['message'] as String?,
+    );
+
+Map<String, dynamic> _$IncrementResponseToJson(IncrementResponse instance) =>
+    <String, dynamic>{'success': instance.success, 'message': instance.message};
diff --git a/Dart/multi_counter/shared/pubspec.yaml b/Dart/multi_counter/shared/pubspec.yaml
new file mode 100644
index 0000000000..9b25a6fb47
--- /dev/null
+++ b/Dart/multi_counter/shared/pubspec.yaml
@@ -0,0 +1,13 @@
+name: multi_counter_shared
+publish_to: none
+resolution: workspace
+
+environment:
+  sdk: ^3.10.0
+
+dependencies:
+  json_annotation: ^4.11.0
+
+dev_dependencies:
+  build_runner: ^2.10.5
+  json_serializable: ^6.12.0
diff --git a/README.md b/README.md
index 9ecbdf405d..6b6fadc66c 100644
--- a/README.md
+++ b/README.md
@@ -21,6 +21,12 @@ To learn how to get started with Cloud Functions for Firebase by having a look a
 
 Minimal samples for each Cloud Functions trigger type.
 
+### Multi-counter
+
+- [Dart](/Dart/multi_counter/)
+
+This sample contains a Flutter app, a shared Dart package, and Dart server-side Cloud Functions showcasing how to build a multi-counter application, as featured in a Cloud Next 2026 talk.
+
 ### Quickstart: Uppercaser for Firestore
 
 - [Node 2nd gen](/Node/quickstarts/uppercase-firestore/)