diff --git a/packages/celest_auth/example/celest/lib/client.dart b/packages/celest_auth/example/celest/lib/client.dart
index fca02407..b668ada0 100644
--- a/packages/celest_auth/example/celest/lib/client.dart
+++ b/packages/celest_auth/example/celest/lib/client.dart
@@ -6,6 +6,7 @@ library; // ignore_for_file: no_leading_underscores_for_library_prefixes
 
 import 'dart:io' as _$io;
 
+import 'package:celest_core/celest_core.dart';
 import 'package:celest_core/src/util/globals.dart';
 import 'package:http/http.dart' as _$http;
 
@@ -25,21 +26,19 @@ enum CelestEnvironment {
       };
 }
 
-class Celest {
+class Celest with CelestBase {
   var _initialized = false;
 
   late CelestEnvironment _currentEnvironment;
 
+  @override
   late _$http.Client httpClient = _$http.Client();
 
   late Uri _baseUri;
 
   final _functions = CelestFunctions();
 
-  late final CelestAuth _auth = CelestAuth(
-    baseUri: _baseUri,
-    httpClient: httpClient,
-  );
+  late final CelestAuth _auth = CelestAuth(this);
 
   T _checkInitialized<T>(T Function() value) {
     if (!_initialized) {
@@ -52,6 +51,7 @@ class Celest {
   CelestEnvironment get currentEnvironment =>
       _checkInitialized(() => _currentEnvironment);
 
+  @override
   Uri get baseUri => _checkInitialized(() => _baseUri);
 
   CelestFunctions get functions => _checkInitialized(() => _functions);
@@ -59,6 +59,9 @@ class Celest {
   CelestAuth get auth => _checkInitialized(() => _auth);
 
   void init({CelestEnvironment environment = CelestEnvironment.local}) {
+    if (environment != _currentEnvironment) {
+      _auth.signOut();
+    }
     _currentEnvironment = environment;
     _baseUri = environment.baseUri;
     _auth.init();
diff --git a/packages/celest_auth/example/celest/lib/src/client/auth.dart b/packages/celest_auth/example/celest/lib/src/client/auth.dart
index 850f36bf..a8573c92 100644
--- a/packages/celest_auth/example/celest/lib/src/client/auth.dart
+++ b/packages/celest_auth/example/celest/lib/src/client/auth.dart
@@ -6,28 +6,10 @@ library; // ignore_for_file: no_leading_underscores_for_library_prefixes
 
 import 'package:celest_auth/src/auth.dart' as _$auth;
 import 'package:celest_auth/src/flows/email_flow.dart' as _$email_flow;
-import 'package:celest_auth/src/state/auth_state.dart' as _$auth_state;
-import 'package:http/http.dart' as _$http;
+import 'package:celest_core/celest_core.dart';
 
-class CelestAuth implements _$auth.Auth {
-  CelestAuth({
-    required Uri baseUri,
-    required _$http.Client httpClient,
-  }) : _hub = _$auth.AuthImpl(
-          baseUri: baseUri,
-          httpClient: httpClient,
-        );
+extension type CelestAuth._(_$auth.AuthImpl _hub) implements _$auth.Auth {
+  CelestAuth(CelestBase celest) : _hub = _$auth.AuthImpl(celest);
 
-  final _$auth.AuthImpl _hub;
-
-  late final _$email_flow.Email email = _$email_flow.Email(_hub);
-
-  @override
-  void init() => _hub.init();
-
-  @override
-  _$auth_state.AuthState get authState => _hub.authState;
-
-  @override
-  Stream<_$auth_state.AuthState> get authStateChanges => _hub.authStateChanges;
+  _$email_flow.Email get email => _$email_flow.Email(_hub);
 }
diff --git a/packages/celest_auth/lib/src/auth.dart b/packages/celest_auth/lib/src/auth.dart
index ccdcf377..a90f532c 100644
--- a/packages/celest_auth/lib/src/auth.dart
+++ b/packages/celest_auth/lib/src/auth.dart
@@ -3,13 +3,11 @@ import 'dart:async';
 import 'package:celest_auth/src/flows/auth_flow.dart';
 import 'package:celest_auth/src/platform/auth_platform.dart';
 import 'package:celest_auth/src/state/auth_state.dart';
-// ignore: implementation_imports
+import 'package:celest_core/celest_core.dart';
 import 'package:celest_core/src/auth/auth_client.dart';
-// ignore: implementation_imports
 import 'package:celest_core/src/storage/local/local_storage.dart';
-// ignore: implementation_imports
 import 'package:celest_core/src/storage/secure/secure_storage.dart';
-import 'package:http/http.dart' as http;
+import 'package:stream_transform/stream_transform.dart';
 
 /// Coordinates and delegates to the various [AuthFlow] to orchestrate
 /// authentication activities.
@@ -17,19 +15,21 @@ import 'package:http/http.dart' as http;
 /// Generated Celest clients extend this class and mix in the various
 /// [AuthFlow]s supported by the backend.
 abstract interface class Auth {
-  /// Initializes Celest Auth.
+  /// **NOTE**: Must be called before any other getters or methods are accessed.
   ///
-  /// Must be called before any other getters or methods are accessed.
-  void init();
+  /// Initializes Celest Auth, returning the initial [AuthState].
+  Future<AuthState> init();
 
   AuthState get authState;
   Stream<AuthState> get authStateChanges;
+
+  /// Signs out the current user, if any.
+  void signOut();
 }
 
 final class AuthImpl implements Auth {
-  AuthImpl({
-    required this.baseUri,
-    required this.httpClient,
+  AuthImpl(
+    this.celest, {
     LocalStorage? localStorage,
     SecureStorage? secureStorage,
   })  : localStorage = localStorage ?? LocalStorage(),
@@ -41,20 +41,27 @@ final class AuthImpl implements Auth {
       const Unauthenticated(); // TODO(dnys1): const AuthInitializing();
 
   @override
-  Stream<AuthState> get authStateChanges => _authStateController.stream;
+  Stream<AuthState> get authStateChanges =>
+      _authStateController.stream.startWith(_authState);
 
   final StreamController<AuthState> _authStateController =
-      StreamController.broadcast(sync: true);
+      StreamController.broadcast();
 
   late final StreamSubscription<AuthState> _authStateSubscription;
   StreamSubscription<AuthFlowState>? _authFlowSubscription;
 
   @override
-  void init() {
-    _authStateSubscription =
-        authStateChanges.listen((state) => _authState = state);
+  Future<AuthState> init() {
+    return _init ??= Future.sync(() {
+      _authStateSubscription =
+          _authStateController.stream.listen((state) => _authState = state);
+      // TODO(dnys1): Proper init
+      return authStateChanges.first;
+    });
   }
 
+  Future<AuthState>? _init;
+
   Future<StreamSink<FlowState>>
       requestFlow<FlowState extends AuthFlowState>() async {
     switch (_authState) {
@@ -70,9 +77,10 @@ final class AuthImpl implements Auth {
           'User is already authenticated. Sign out before continuing.',
         );
       case Unauthenticated() || NeedsReauthentication():
-        await _authFlowSubscription?.cancel();
+        unawaited(_authFlowSubscription?.cancel());
         final previousState = _authState;
         final controller = StreamController<FlowState>(
+          sync: true,
           onCancel: () => _authStateController.add(previousState),
         );
         _authFlowSubscription = controller.stream.listen(
@@ -87,16 +95,18 @@ final class AuthImpl implements Auth {
     }
   }
 
-  final Uri baseUri;
-  final http.Client httpClient;
+  @override
+  void signOut() {
+    localStorage.delete('userId');
+    secureStorage.delete('cork');
+    _authStateController.add(const Unauthenticated());
+  }
 
+  final CelestBase celest;
   final LocalStorage localStorage;
   final SecureStorage secureStorage;
 
-  late final AuthClient protocol = AuthClient(
-    baseUri: baseUri,
-    httpClient: httpClient,
-  );
+  late final AuthClient protocol = AuthClient(celest);
   late final AuthPlatform platform = AuthPlatform(protocol: protocol);
 
   Future<void> close() async {
diff --git a/packages/celest_auth/lib/src/flows/email_flow.dart b/packages/celest_auth/lib/src/flows/email_flow.dart
index 30327551..a46e5c52 100644
--- a/packages/celest_auth/lib/src/flows/email_flow.dart
+++ b/packages/celest_auth/lib/src/flows/email_flow.dart
@@ -8,11 +8,7 @@ import 'package:celest_core/src/auth/auth_protocol.dart';
 import 'package:celest_core/src/auth/otp/otp_types.dart';
 import 'package:state_notifier/state_notifier.dart';
 
-final class Email {
-  Email(this._hub);
-
-  final AuthImpl _hub;
-
+extension type Email(AuthImpl _hub) {
   Future<EmailSignUpNeedsVerification> signUp({
     required String email,
   }) async {
diff --git a/packages/celest_auth/pubspec.yaml b/packages/celest_auth/pubspec.yaml
index a39033b8..572a8f97 100644
--- a/packages/celest_auth/pubspec.yaml
+++ b/packages/celest_auth/pubspec.yaml
@@ -31,6 +31,7 @@ dependencies:
   shelf: ^1.4.1
   shelf_router: ^1.1.4
   state_notifier: ^1.0.0
+  stream_transform: ^2.1.0
   web: ^0.5.0
 
 dev_dependencies:
diff --git a/packages/celest_core/lib/celest_core.dart b/packages/celest_core/lib/celest_core.dart
index 08c55a9b..61d480d5 100644
--- a/packages/celest_core/lib/celest_core.dart
+++ b/packages/celest_core/lib/celest_core.dart
@@ -5,6 +5,9 @@ library;
 export 'src/auth/auth_exception.dart';
 export 'src/auth/user.dart';
 
+/// Base
+export 'src/base/celest_base.dart';
+
 /// Exceptions
 export 'src/exception/celest_exception.dart';
 export 'src/exception/cloud_exception.dart';
diff --git a/packages/celest_core/lib/src/auth/auth_client.dart b/packages/celest_core/lib/src/auth/auth_client.dart
index f8b555d5..0a88bbaf 100644
--- a/packages/celest_core/lib/src/auth/auth_client.dart
+++ b/packages/celest_core/lib/src/auth/auth_client.dart
@@ -3,41 +3,24 @@ import 'package:celest_core/src/auth/auth_protocol.dart';
 import 'package:celest_core/src/auth/otp/otp_types.dart';
 import 'package:celest_core/src/auth/passkeys/passkey_types.dart';
 import 'package:celest_core/src/base/base_protocol.dart';
-import 'package:http/http.dart' as http;
 
 final class AuthClient implements AuthProtocol {
-  AuthClient({
-    required this.baseUri,
-    http.Client? httpClient,
-  }) : _client = httpClient ?? http.Client();
+  AuthClient(this.celest);
 
-  final http.Client _client;
-  final Uri baseUri;
+  final CelestBase celest;
 
   @override
-  late final PasskeyClient passkeys = PasskeyClient(
-    baseUri: baseUri,
-    httpClient: _client,
-  );
+  late final PasskeyClient passkeys = PasskeyClient(celest);
 
   @override
-  late final EmailClient email = EmailClient(
-    baseUri: baseUri,
-    httpClient: _client,
-  );
+  late final EmailClient email = EmailClient(celest);
 }
 
 final class PasskeyClient with BaseProtocol implements PasskeyProtocol {
-  PasskeyClient({
-    required this.baseUri,
-    required this.httpClient,
-  });
+  PasskeyClient(this.celest);
 
   @override
-  final http.Client httpClient;
-
-  @override
-  final Uri baseUri;
+  final CelestBase celest;
 
   @override
   Future<PasskeyOptions> authenticate({
@@ -63,16 +46,10 @@ final class PasskeyClient with BaseProtocol implements PasskeyProtocol {
 }
 
 final class EmailClient with BaseProtocol implements EmailProtocol {
-  EmailClient({
-    required this.baseUri,
-    required this.httpClient,
-  });
-
-  @override
-  final http.Client httpClient;
+  EmailClient(this.celest);
 
   @override
-  final Uri baseUri;
+  final CelestBase celest;
 
   @override
   Future<OtpParameters> sendOtp({
diff --git a/packages/celest_core/lib/src/base/base_protocol.dart b/packages/celest_core/lib/src/base/base_protocol.dart
index 647c5dff..7338ff19 100644
--- a/packages/celest_core/lib/src/base/base_protocol.dart
+++ b/packages/celest_core/lib/src/base/base_protocol.dart
@@ -1,17 +1,17 @@
 import 'dart:convert';
 
+import 'package:celest_core/src/base/celest_base.dart';
 import 'package:http/http.dart' as http;
 
 mixin BaseProtocol {
-  http.Client get httpClient;
-  Uri get baseUri;
+  CelestBase get celest;
 
   Future<Map<String, Object?>> postJson(
     String path,
     Map<String, Object?> json,
   ) async {
-    final uri = baseUri.resolve(path);
-    final resp = await httpClient.post(
+    final uri = celest.baseUri.resolve(path);
+    final resp = await celest.httpClient.post(
       uri,
       body: jsonEncode(json),
       headers: {
diff --git a/packages/celest_core/lib/src/base/celest_base.dart b/packages/celest_core/lib/src/base/celest_base.dart
new file mode 100644
index 00000000..dc6d5430
--- /dev/null
+++ b/packages/celest_core/lib/src/base/celest_base.dart
@@ -0,0 +1,6 @@
+import 'package:http/http.dart' as http;
+
+abstract mixin class CelestBase {
+  http.Client get httpClient;
+  Uri get baseUri;
+}