diff --git a/docs/tasks/routing.md b/docs/tasks/routing.md
index 87696d1..fdd2272 100644
--- a/docs/tasks/routing.md
+++ b/docs/tasks/routing.md
@@ -3,22 +3,14 @@ title: AppView Routing + Trending Milestones
 updated: 2026-04-29
 ---
 
-## M0 - Research + Planning (Complete)
-
-- [x] Validate Bluesky and Blacksky AppView DID/service identities
-- [x] Validate live compatibility for trends/trending-topics endpoints
-- [x] Capture provider divergence (link formats, `suggested` behavior)
-- [x] Update routing spec with provider-switch UX contract and state safety rules
-- [x] Update routing/task plan to include Trending button + `/trending` screen
-
 ## M1 - Core Routing Model
 
-- [ ] Add `appview_provider` setting with defaults and validation
-- [ ] Add login-screen provider selector (Bluesky + Blacksky visible by default)
-- [ ] Persist login-screen provider choice before any auth/network call
-- [ ] Add provider descriptor (`serviceDid`, `publicBaseUrl`, `entrywayUrl`, `webBaseUrl`)
-- [ ] Add `AppViewRouter` abstraction for endpoint/header/link resolution
-- [ ] Add unit tests for provider normalization/defaults and bootstrap ordering
+- [x] Add `appview_provider` setting with defaults and validation
+- [x] Add login-screen provider selector (Bluesky + Blacksky visible by default)
+- [x] Persist login-screen provider choice before any auth/network call
+- [x] Add provider descriptor (`serviceDid`, `publicBaseUrl`, `entrywayUrl`, `webBaseUrl`)
+- [x] Add `AppViewRouter` abstraction for endpoint/header/link resolution
+- [x] Add unit tests for provider normalization/defaults and bootstrap ordering
 
 ## M2 - Header + Request Integration
 
diff --git a/lib/core/bootstrap/auth_bootstrap.dart b/lib/core/bootstrap/auth_bootstrap.dart
new file mode 100644
index 0000000..e4e3e06
--- /dev/null
+++ b/lib/core/bootstrap/auth_bootstrap.dart
@@ -0,0 +1,20 @@
+import 'package:lazurite/features/auth/data/auth_repository.dart';
+import 'package:lazurite/features/auth/data/models/auth_models.dart';
+
+class AuthBootstrapResult {
+  const AuthBootstrapResult({required this.authRepository, required this.restoredSession});
+
+  final AuthRepository authRepository;
+  final AuthTokens? restoredSession;
+}
+
+Future<AuthBootstrapResult> bootstrapAuthDependencies({
+  required Future<void> Function() loadSettings,
+  required AuthRepository Function() createAuthRepository,
+  required Future<AuthTokens?> Function(AuthRepository authRepository) restoreSession,
+}) async {
+  await loadSettings();
+  final authRepository = createAuthRepository();
+  final restoredSession = await restoreSession(authRepository);
+  return AuthBootstrapResult(authRepository: authRepository, restoredSession: restoredSession);
+}
diff --git a/lib/core/database/app_database.dart b/lib/core/database/app_database.dart
index 5deb11c..3c258a7 100644
--- a/lib/core/database/app_database.dart
+++ b/lib/core/database/app_database.dart
@@ -26,13 +26,14 @@ class AppDatabase extends _$AppDatabase {
   static const activeAccountDidSettingKey = 'active_account_did';
 
   @override
-  int get schemaVersion => 17;
+  int get schemaVersion => 18;
 
   @override
   MigrationStrategy get migration => MigrationStrategy(
     onCreate: (migrator) async {
       await migrator.createAll();
       await customStatement("INSERT OR IGNORE INTO settings (key, value) VALUES ('typeahead_provider', 'bluesky')");
+      await customStatement("INSERT OR IGNORE INTO settings (key, value) VALUES ('appview_provider', 'bluesky')");
     },
     onUpgrade: (migrator, from, to) async {
       if (from < 2) {
@@ -119,6 +120,9 @@ class AppDatabase extends _$AppDatabase {
       if (from < 17) {
         await customStatement("INSERT OR IGNORE INTO settings (key, value) VALUES ('typeahead_provider', 'bluesky')");
       }
+      if (from < 18) {
+        await customStatement("INSERT OR IGNORE INTO settings (key, value) VALUES ('appview_provider', 'bluesky')");
+      }
     },
   );
 
diff --git a/lib/core/network/app_view_provider.dart b/lib/core/network/app_view_provider.dart
new file mode 100644
index 0000000..5d3c04f
--- /dev/null
+++ b/lib/core/network/app_view_provider.dart
@@ -0,0 +1,53 @@
+class AppViewProviderDescriptor {
+  const AppViewProviderDescriptor({
+    required this.key,
+    required this.serviceDid,
+    required this.publicBaseUrl,
+    required this.entrywayUrl,
+    required this.webBaseUrl,
+  });
+
+  final String key;
+  final String serviceDid;
+  final Uri publicBaseUrl;
+  final Uri entrywayUrl;
+  final Uri webBaseUrl;
+}
+
+abstract final class AppViewProviders {
+  static const String blueskyKey = 'bluesky';
+  static const String blackskyKey = 'blacksky';
+  static const String defaultKey = blueskyKey;
+  static const Set<String> supportedKeys = {blueskyKey, blackskyKey};
+
+  static final AppViewProviderDescriptor bluesky = AppViewProviderDescriptor(
+    key: blueskyKey,
+    serviceDid: 'did:web:api.bsky.app#bsky_appview',
+    publicBaseUrl: Uri.https('public.api.bsky.app'),
+    entrywayUrl: Uri.https('bsky.social'),
+    webBaseUrl: Uri.https('bsky.app'),
+  );
+
+  static final AppViewProviderDescriptor blacksky = AppViewProviderDescriptor(
+    key: blackskyKey,
+    serviceDid: 'did:web:api.blacksky.community#bsky_appview',
+    publicBaseUrl: Uri.https('api.blacksky.community'),
+    entrywayUrl: Uri.https('blacksky.app'),
+    webBaseUrl: Uri.https('blacksky.app'),
+  );
+
+  static final Map<String, AppViewProviderDescriptor> _builtIns = {blueskyKey: bluesky, blackskyKey: blacksky};
+
+  static String normalizeSettingKey(String? rawKey) {
+    final normalized = rawKey?.trim().toLowerCase();
+    if (normalized == null || !supportedKeys.contains(normalized)) {
+      return defaultKey;
+    }
+    return normalized;
+  }
+
+  static AppViewProviderDescriptor descriptorForSetting(String? rawKey) {
+    final normalizedKey = normalizeSettingKey(rawKey);
+    return _builtIns[normalizedKey] ?? bluesky;
+  }
+}
diff --git a/lib/core/network/app_view_router.dart b/lib/core/network/app_view_router.dart
new file mode 100644
index 0000000..7792dd4
--- /dev/null
+++ b/lib/core/network/app_view_router.dart
@@ -0,0 +1,30 @@
+import 'package:lazurite/core/network/app_view_provider.dart';
+
+class AppViewRouter {
+  AppViewRouter({required this.provider});
+
+  final AppViewProviderDescriptor provider;
+
+  Map<String, String> appBskyProxyHeaders() => {'atproto-proxy': provider.serviceDid};
+
+  Uri publicEndpoint(String xrpcPath, [Map<String, String> queryParameters = const {}]) {
+    final normalizedPath = xrpcPath.startsWith('/') ? xrpcPath : '/$xrpcPath';
+    return provider.publicBaseUrl.replace(path: normalizedPath, queryParameters: queryParameters);
+  }
+
+  Uri entrywayForAuth() => provider.entrywayUrl;
+
+  Uri resolveWebLink(String relativeOrAbsolute) {
+    final trimmed = relativeOrAbsolute.trim();
+    if (trimmed.isEmpty) {
+      return provider.webBaseUrl;
+    }
+
+    final parsed = Uri.tryParse(trimmed);
+    if (parsed != null && parsed.hasScheme) {
+      return parsed;
+    }
+
+    return provider.webBaseUrl.resolve(trimmed);
+  }
+}
diff --git a/lib/features/auth/data/auth_repository.dart b/lib/features/auth/data/auth_repository.dart
index aca0132..a574aa5 100644
--- a/lib/features/auth/data/auth_repository.dart
+++ b/lib/features/auth/data/auth_repository.dart
@@ -11,6 +11,7 @@ import 'package:http/http.dart' as http;
 import 'package:lazurite/core/database/app_database.dart';
 import 'package:lazurite/core/logging/app_logger.dart';
 import 'package:lazurite/core/network/atproto_host_resolver.dart';
+import 'package:lazurite/core/network/app_view_provider.dart';
 import 'package:lazurite/core/network/xrpc_client_factory.dart';
 import 'package:lazurite/features/auth/data/models/auth_models.dart';
 import 'package:url_launcher/url_launcher.dart';
@@ -33,12 +34,14 @@ class AuthRepository {
     SupportsCloseForMode supportsCloseForMode = supportsCloseForLaunchMode,
     OAuthRefreshSession oauthRefreshSession = _defaultOAuthRefreshSession,
     Future<OAuthClientMetadata> Function(String clientId) loadClientMetadata = getClientMetadata,
+    String Function()? oauthServiceResolver,
   }) : _database = database,
        _launchUrlWithMode = launchUrlWithMode,
        _closeInAppBrowser = closeInAppBrowser,
        _supportsCloseForMode = supportsCloseForMode,
        _oauthRefreshSession = oauthRefreshSession,
-       _loadClientMetadata = loadClientMetadata;
+       _loadClientMetadata = loadClientMetadata,
+       _oauthServiceResolver = oauthServiceResolver ?? _defaultOAuthServiceResolver;
 
   static const String kClientId = 'https://lazurite.stormlightlabs.org/client-metadata.json';
   static const String _oauthService = 'bsky.social';
@@ -51,6 +54,7 @@ class AuthRepository {
   final SupportsCloseForMode _supportsCloseForMode;
   final OAuthRefreshSession _oauthRefreshSession;
   final Future<OAuthClientMetadata> Function(String clientId) _loadClientMetadata;
+  final String Function() _oauthServiceResolver;
 
   HttpServer? _callbackServer;
   StreamSubscription<HttpRequest>? _callbackSubscription;
@@ -148,7 +152,7 @@ class AuthRepository {
     try {
       _oauthCompleter = Completer<AuthTokens?>();
       _pendingHandle = handle.trim();
-      _pendingService = _oauthService;
+      _pendingService = normalizeAtprotoServiceHost(_oauthServiceResolver()) ?? _oauthService;
       log.i('AuthRepository: Starting OAuth login for ${_pendingHandle!}');
 
       final metadata = await _loadClientMetadata(kClientId);
@@ -723,6 +727,10 @@ class AuthRepository {
     return oauthClient.refresh(session);
   }
 
+  static String _defaultOAuthServiceResolver() {
+    return AppViewProviders.descriptorForSetting(AppViewProviders.defaultKey).entrywayUrl.host;
+  }
+
   String _summarizeOAuthRefreshError(Object error) {
     final message = error.toString().replaceAll('\n', ' ').trim();
 
diff --git a/lib/features/auth/presentation/login_screen.dart b/lib/features/auth/presentation/login_screen.dart
index 1512c7b..fc29f35 100644
--- a/lib/features/auth/presentation/login_screen.dart
+++ b/lib/features/auth/presentation/login_screen.dart
@@ -1,9 +1,14 @@
+import 'dart:async';
+
 import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
 import 'package:flutter_svg/flutter_svg.dart';
 import 'package:go_router/go_router.dart';
+import 'package:lazurite/core/network/app_view_provider.dart';
 import 'package:lazurite/features/auth/bloc/auth_bloc.dart';
+import 'package:lazurite/features/settings/bloc/settings_cubit.dart';
+import 'package:lazurite/features/settings/bloc/settings_state.dart';
 import 'package:lazurite/features/typeahead/data/typeahead_repository.dart';
 import 'package:lazurite/features/typeahead/data/typeahead_result.dart';
 import 'package:lazurite/features/typeahead/presentation/typeahead_text_field.dart';
@@ -22,6 +27,7 @@ class _LoginScreenState extends State<LoginScreen> {
   final _appPasswordController = TextEditingController();
   final _formKey = GlobalKey<FormState>();
   bool _showDebugForm = false;
+  bool _isPersistingProvider = false;
   late final TypeaheadRepository _typeaheadRepository;
 
   @override
@@ -38,19 +44,33 @@ class _LoginScreenState extends State<LoginScreen> {
     super.dispose();
   }
 
-  void _onOAuthLogin() {
+  Future<void> _onOAuthLogin() async {
     if (!_isHandleValid()) {
       return;
     }
 
+    final persisted = await _persistSelectedProvider();
+    if (!persisted) {
+      return;
+    }
+    if (!mounted) {
+      return;
+    }
     context.read<AuthBloc>().add(OAuthLoginRequested(handle: _handleController.text.trim()));
   }
 
-  void _onAppPasswordLogin() {
+  Future<void> _onAppPasswordLogin() async {
     if (!(_formKey.currentState?.validate() ?? false)) {
       return;
     }
 
+    final persisted = await _persistSelectedProvider();
+    if (!persisted) {
+      return;
+    }
+    if (!mounted) {
+      return;
+    }
     context.read<AuthBloc>().add(
       LoginRequested(handle: _handleController.text.trim(), appPassword: _appPasswordController.text.trim()),
     );
@@ -62,7 +82,35 @@ class _LoginScreenState extends State<LoginScreen> {
 
   void _onTypeaheadSelected(TypeaheadResult result) {
     _handleController.text = result.handle;
-    _onOAuthLogin();
+    unawaited(_onOAuthLogin());
+  }
+
+  Future<bool> _persistSelectedProvider() async {
+    final settingsCubit = context.read<SettingsCubit>();
+    if (_isPersistingProvider) {
+      return false;
+    }
+
+    setState(() {
+      _isPersistingProvider = true;
+    });
+    try {
+      await settingsCubit.setAppViewProvider(settingsCubit.state.appViewProvider);
+      return true;
+    } catch (error) {
+      if (mounted) {
+        ScaffoldMessenger.of(
+          context,
+        ).showSnackBar(SnackBar(content: Text('Failed to save provider selection: $error')));
+      }
+      return false;
+    } finally {
+      if (mounted) {
+        setState(() {
+          _isPersistingProvider = false;
+        });
+      }
+    }
   }
 
   @override
@@ -111,6 +159,39 @@ class _LoginScreenState extends State<LoginScreen> {
                           style: theme.textTheme.bodyLarge?.copyWith(color: colorScheme.onSurfaceVariant),
                         ),
                         const SizedBox(height: 32),
+                        BlocBuilder<SettingsCubit, SettingsState>(
+                          builder: (context, settingsState) {
+                            final selectedProvider = settingsState.appViewProvider;
+                            return Column(
+                              crossAxisAlignment: CrossAxisAlignment.start,
+                              children: [
+                                Text(
+                                  'AppView Provider',
+                                  style: theme.textTheme.labelLarge?.copyWith(fontWeight: FontWeight.w600),
+                                ),
+                                const SizedBox(height: 8),
+                                SegmentedButton<String>(
+                                  segments: const [
+                                    ButtonSegment<String>(value: AppViewProviders.blueskyKey, label: Text('Bluesky')),
+                                    ButtonSegment<String>(value: AppViewProviders.blackskyKey, label: Text('Blacksky')),
+                                  ],
+                                  selected: {selectedProvider},
+                                  onSelectionChanged: (selection) {
+                                    unawaited(context.read<SettingsCubit>().setAppViewProvider(selection.first));
+                                  },
+                                ),
+                                const SizedBox(height: 8),
+                                Text(
+                                  selectedProvider == AppViewProviders.blackskyKey
+                                      ? 'Sign-in will use Blacksky entryway defaults.'
+                                      : 'Sign-in will use Bluesky entryway defaults.',
+                                  style: theme.textTheme.bodySmall?.copyWith(color: colorScheme.onSurfaceVariant),
+                                ),
+                                const SizedBox(height: 16),
+                              ],
+                            );
+                          },
+                        ),
                         TypeaheadTextField(
                           controller: _handleController,
                           repository: _typeaheadRepository,
@@ -136,16 +217,21 @@ class _LoginScreenState extends State<LoginScreen> {
                         const SizedBox(height: 20),
                         BlocBuilder<AuthBloc, AuthState>(
                           builder: (context, state) {
+                            final busy = state.isLoading || _isPersistingProvider;
                             return FilledButton.icon(
-                              onPressed: state.isLoading ? null : _onOAuthLogin,
-                              icon: state.isLoading
+                              onPressed: busy
+                                  ? null
+                                  : () {
+                                      unawaited(_onOAuthLogin());
+                                    },
+                              icon: busy
                                   ? const SizedBox(
                                       width: 18,
                                       height: 18,
                                       child: CircularProgressIndicator(strokeWidth: 2),
                                     )
                                   : const Icon(Icons.language),
-                              label: Text(state.isLoading ? 'Starting sign in...' : 'Continue'),
+                              label: Text(busy ? 'Starting sign in...' : 'Continue'),
                               style: FilledButton.styleFrom(padding: const EdgeInsets.symmetric(vertical: 18)),
                             );
                           },
@@ -206,8 +292,13 @@ class _LoginScreenState extends State<LoginScreen> {
                                     const SizedBox(height: 12),
                                     BlocBuilder<AuthBloc, AuthState>(
                                       builder: (context, state) {
+                                        final busy = state.isLoading || _isPersistingProvider;
                                         return OutlinedButton.icon(
-                                          onPressed: state.isLoading ? null : _onAppPasswordLogin,
+                                          onPressed: busy
+                                              ? null
+                                              : () {
+                                                  unawaited(_onAppPasswordLogin());
+                                                },
                                           icon: const Icon(Icons.login),
                                           label: const Text('Sign In'),
                                         );
diff --git a/lib/features/settings/bloc/settings_cubit.dart b/lib/features/settings/bloc/settings_cubit.dart
index 6a244e9..e30d5f2 100644
--- a/lib/features/settings/bloc/settings_cubit.dart
+++ b/lib/features/settings/bloc/settings_cubit.dart
@@ -1,5 +1,6 @@
 import 'package:flutter_bloc/flutter_bloc.dart';
 import 'package:lazurite/core/database/app_database.dart';
+import 'package:lazurite/core/network/app_view_provider.dart';
 import 'package:lazurite/core/theme/app_theme.dart';
 import 'package:lazurite/core/theme/feed_layout.dart';
 import 'package:lazurite/features/search/data/search_scope.dart';
@@ -47,6 +48,7 @@ class SettingsCubit extends Cubit<SettingsState> {
   static const String _keyTypeaheadProvider = 'typeahead_provider';
   static const String _defaultTypeaheadProvider = 'bluesky';
   static const Set<String> _supportedTypeaheadProviders = {'bluesky', 'community'};
+  static const String _keyAppViewProvider = 'appview_provider';
 
   Future<void> loadSettings() async {
     final paletteStr = await database.getSetting(_keyThemePalette);
@@ -62,9 +64,11 @@ class SettingsCubit extends Cubit<SettingsState> {
     final searchScopeStr = await database.getSetting(_keySearchScope);
     final semanticSearchMaxResultsStr = await database.getSetting(_keySemanticSearchMaxResults);
     final typeaheadProviderStr = await database.getSetting(_keyTypeaheadProvider);
+    final appViewProviderStr = await database.getSetting(_keyAppViewProvider);
     final resolvedTypeaheadProvider = _supportedTypeaheadProviders.contains(typeaheadProviderStr)
         ? typeaheadProviderStr!
         : _defaultTypeaheadProvider;
+    final resolvedAppViewProvider = AppViewProviders.normalizeSettingKey(appViewProviderStr);
 
     emit(
       state.copyWith(
@@ -80,6 +84,7 @@ class SettingsCubit extends Cubit<SettingsState> {
         searchScope: SearchScope.values.firstWhere((s) => s.name == searchScopeStr, orElse: () => SearchScope.both),
         semanticSearchMaxResults: int.tryParse(semanticSearchMaxResultsStr ?? '') ?? 20,
         typeaheadProvider: resolvedTypeaheadProvider,
+        appViewProvider: resolvedAppViewProvider,
       ),
     );
   }
@@ -163,4 +168,10 @@ class SettingsCubit extends Cubit<SettingsState> {
     await database.setSetting(_keyTypeaheadProvider, normalizedProvider);
     emit(state.copyWith(typeaheadProvider: normalizedProvider));
   }
+
+  Future<void> setAppViewProvider(String provider) async {
+    final normalizedProvider = AppViewProviders.normalizeSettingKey(provider);
+    await database.setSetting(_keyAppViewProvider, normalizedProvider);
+    emit(state.copyWith(appViewProvider: normalizedProvider));
+  }
 }
diff --git a/lib/features/settings/bloc/settings_state.dart b/lib/features/settings/bloc/settings_state.dart
index 9d1bbdf..5a49c7c 100644
--- a/lib/features/settings/bloc/settings_state.dart
+++ b/lib/features/settings/bloc/settings_state.dart
@@ -19,6 +19,7 @@ class SettingsState extends Equatable {
     this.searchScope = SearchScope.both,
     this.semanticSearchMaxResults = 20,
     this.typeaheadProvider = 'bluesky',
+    this.appViewProvider = 'bluesky',
   });
 
   final AppThemePalette themePalette;
@@ -42,6 +43,9 @@ class SettingsState extends Equatable {
   /// Configured typeahead backend provider (`bluesky` or `community`).
   final String typeaheadProvider;
 
+  /// Configured AppView provider (`bluesky` or `blacksky`).
+  final String appViewProvider;
+
   SettingsState copyWith({
     AppThemePalette? themePalette,
     AppThemeVariant? themeVariant,
@@ -55,6 +59,7 @@ class SettingsState extends Equatable {
     SearchScope? searchScope,
     int? semanticSearchMaxResults,
     String? typeaheadProvider,
+    String? appViewProvider,
   }) {
     return SettingsState(
       themePalette: themePalette ?? this.themePalette,
@@ -71,6 +76,7 @@ class SettingsState extends Equatable {
       searchScope: searchScope ?? this.searchScope,
       semanticSearchMaxResults: semanticSearchMaxResults ?? this.semanticSearchMaxResults,
       typeaheadProvider: typeaheadProvider ?? this.typeaheadProvider,
+      appViewProvider: appViewProvider ?? this.appViewProvider,
     );
   }
 
@@ -88,5 +94,6 @@ class SettingsState extends Equatable {
     searchScope,
     semanticSearchMaxResults,
     typeaheadProvider,
+    appViewProvider,
   ];
 }
diff --git a/lib/main.dart b/lib/main.dart
index 7a032f0..508a5f9 100644
--- a/lib/main.dart
+++ b/lib/main.dart
@@ -5,11 +5,14 @@ import 'package:bluesky/bluesky_chat.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
 import 'package:go_router/go_router.dart';
+import 'package:lazurite/core/bootstrap/auth_bootstrap.dart';
 import 'package:lazurite/core/database/app_database.dart';
 import 'package:lazurite/core/embedding/embedding_service.dart';
 import 'package:lazurite/core/logging/app_logger.dart';
 import 'package:lazurite/core/logging/logging_bloc_observer.dart';
 import 'package:lazurite/core/logging/logging_navigator_observer.dart';
+import 'package:lazurite/core/network/app_view_provider.dart';
+import 'package:lazurite/core/network/app_view_router.dart';
 import 'package:lazurite/core/network/xrpc_client_factory.dart';
 import 'package:lazurite/core/objectbox/objectbox_store.dart';
 import 'package:lazurite/core/router/app_router.dart';
@@ -62,17 +65,27 @@ Future<void> main() async {
   final objectBoxStore = await ObjectBoxStore.open();
   final embeddingService = EmbeddingService();
   unawaited(embeddingService.initialize());
-  final authRepository = AuthRepository(database: database);
-  final restoredSession = await authRepository.restoreSession();
+  final settingsCubit = SettingsCubit(database: database);
+  final authBootstrap = await bootstrapAuthDependencies(
+    loadSettings: settingsCubit.loadSettings,
+    createAuthRepository: () => AuthRepository(
+      database: database,
+      oauthServiceResolver: () {
+        final provider = AppViewProviders.descriptorForSetting(settingsCubit.state.appViewProvider);
+        final router = AppViewRouter(provider: provider);
+        return router.entrywayForAuth().host;
+      },
+    ),
+    restoreSession: (authRepository) => authRepository.restoreSession(),
+  );
+  final authRepository = authBootstrap.authRepository;
+  final restoredSession = authBootstrap.restoredSession;
   final authBloc = AuthBloc(
     authRepository: authRepository,
     initialState: restoredSession != null
         ? AuthState.authenticated(restoredSession)
         : const AuthState.unauthenticated(),
   );
-
-  final settingsCubit = SettingsCubit(database: database);
-  await settingsCubit.loadSettings();
   final connectivityCubit = ConnectivityCubit(simulateOffline: settingsCubit.state.simulateOffline);
 
   final accountSwitcherCubit = AccountSwitcherCubit(database: database, authRepository: authRepository);
diff --git a/test/core/bootstrap/auth_bootstrap_test.dart b/test/core/bootstrap/auth_bootstrap_test.dart
new file mode 100644
index 0000000..e240ac9
--- /dev/null
+++ b/test/core/bootstrap/auth_bootstrap_test.dart
@@ -0,0 +1,36 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:lazurite/core/bootstrap/auth_bootstrap.dart';
+import 'package:lazurite/features/auth/data/auth_repository.dart';
+import 'package:lazurite/features/auth/data/models/auth_models.dart';
+import 'package:mocktail/mocktail.dart';
+
+class MockAuthRepository extends Mock implements AuthRepository {}
+
+void main() {
+  group('bootstrapAuthDependencies', () {
+    test('loads settings before creating and restoring auth repository', () async {
+      final callOrder = <String>[];
+      final authRepository = MockAuthRepository();
+      const restoredSession = AuthTokens(accessToken: 'token', did: 'did:plc:test', handle: 'user.bsky.social');
+
+      final result = await bootstrapAuthDependencies(
+        loadSettings: () async {
+          callOrder.add('loadSettings');
+        },
+        createAuthRepository: () {
+          callOrder.add('createAuthRepository');
+          return authRepository;
+        },
+        restoreSession: (repository) async {
+          expect(repository, same(authRepository));
+          callOrder.add('restoreSession');
+          return restoredSession;
+        },
+      );
+
+      expect(callOrder, equals(<String>['loadSettings', 'createAuthRepository', 'restoreSession']));
+      expect(result.authRepository, same(authRepository));
+      expect(result.restoredSession, same(restoredSession));
+    });
+  });
+}
diff --git a/test/core/database/app_database_test.dart b/test/core/database/app_database_test.dart
index cad12fa..4f0611b 100644
--- a/test/core/database/app_database_test.dart
+++ b/test/core/database/app_database_test.dart
@@ -228,6 +228,11 @@ void main() {
         expect(value, equals('bluesky'));
       });
 
+      test('should seed default appview provider on database creation', () async {
+        final value = await database.getSetting('appview_provider');
+        expect(value, equals('bluesky'));
+      });
+
       test('should set and get setting', () async {
         await database.setSetting('theme', 'dark');
         final value = await database.getSetting('theme');
diff --git a/test/core/network/app_view_provider_test.dart b/test/core/network/app_view_provider_test.dart
new file mode 100644
index 0000000..dccab04
--- /dev/null
+++ b/test/core/network/app_view_provider_test.dart
@@ -0,0 +1,31 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:lazurite/core/network/app_view_provider.dart';
+
+void main() {
+  group('AppViewProviders', () {
+    test('normalizes known provider keys', () {
+      expect(AppViewProviders.normalizeSettingKey(' BLACKSKY '), equals('blacksky'));
+      expect(AppViewProviders.normalizeSettingKey('bluesky'), equals('bluesky'));
+    });
+
+    test('falls back to default for unknown keys', () {
+      expect(AppViewProviders.normalizeSettingKey('unknown'), equals(AppViewProviders.defaultKey));
+      expect(AppViewProviders.normalizeSettingKey(null), equals(AppViewProviders.defaultKey));
+    });
+
+    test('returns descriptors with expected fields', () {
+      final bluesky = AppViewProviders.descriptorForSetting('bluesky');
+      final blacksky = AppViewProviders.descriptorForSetting('blacksky');
+
+      expect(bluesky.serviceDid, equals('did:web:api.bsky.app#bsky_appview'));
+      expect(bluesky.publicBaseUrl.host, equals('public.api.bsky.app'));
+      expect(bluesky.entrywayUrl.host, equals('bsky.social'));
+      expect(bluesky.webBaseUrl.host, equals('bsky.app'));
+
+      expect(blacksky.serviceDid, equals('did:web:api.blacksky.community#bsky_appview'));
+      expect(blacksky.publicBaseUrl.host, equals('api.blacksky.community'));
+      expect(blacksky.entrywayUrl.host, equals('blacksky.app'));
+      expect(blacksky.webBaseUrl.host, equals('blacksky.app'));
+    });
+  });
+}
diff --git a/test/core/network/app_view_router_test.dart b/test/core/network/app_view_router_test.dart
new file mode 100644
index 0000000..cf01e6e
--- /dev/null
+++ b/test/core/network/app_view_router_test.dart
@@ -0,0 +1,32 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:lazurite/core/network/app_view_provider.dart';
+import 'package:lazurite/core/network/app_view_router.dart';
+
+void main() {
+  group('AppViewRouter', () {
+    test('builds proxy headers and public endpoint URI', () {
+      final router = AppViewRouter(provider: AppViewProviders.blacksky);
+
+      expect(router.appBskyProxyHeaders(), equals({'atproto-proxy': 'did:web:api.blacksky.community#bsky_appview'}));
+      expect(
+        router.publicEndpoint('/xrpc/app.bsky.unspecced.getTrends', {'limit': '10'}).toString(),
+        equals('https://api.blacksky.community/xrpc/app.bsky.unspecced.getTrends?limit=10'),
+      );
+    });
+
+    test('resolves relative links against provider web base', () {
+      final router = AppViewRouter(provider: AppViewProviders.bluesky);
+
+      expect(router.resolveWebLink('/topic/abc123').toString(), equals('https://bsky.app/topic/abc123'));
+      expect(
+        router.resolveWebLink('/profile/alice.bsky.social/feed/aaabbb').toString(),
+        equals('https://bsky.app/profile/alice.bsky.social/feed/aaabbb'),
+      );
+    });
+
+    test('returns absolute links unchanged', () {
+      final router = AppViewRouter(provider: AppViewProviders.bluesky);
+      expect(router.resolveWebLink('https://example.com/path').toString(), equals('https://example.com/path'));
+    });
+  });
+}
diff --git a/test/core/router/app_router_test.dart b/test/core/router/app_router_test.dart
index aac5fa9..66a3872 100644
--- a/test/core/router/app_router_test.dart
+++ b/test/core/router/app_router_test.dart
@@ -363,8 +363,11 @@ void main() {
     final router = AppRouter(authBloc: authBloc).router;
 
     await tester.pumpWidget(
-      BlocProvider<AuthBloc>.value(
-        value: authBloc,
+      MultiBlocProvider(
+        providers: [
+          BlocProvider<AuthBloc>.value(value: authBloc),
+          BlocProvider<SettingsCubit>.value(value: settingsCubit),
+        ],
         child: MaterialApp.router(routerConfig: router),
       ),
     );
diff --git a/test/features/auth/presentation/login_screen_test.dart b/test/features/auth/presentation/login_screen_test.dart
index 32bef22..704ed39 100644
--- a/test/features/auth/presentation/login_screen_test.dart
+++ b/test/features/auth/presentation/login_screen_test.dart
@@ -3,7 +3,10 @@ import 'package:flutter/material.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:go_router/go_router.dart';
+import 'package:lazurite/core/theme/app_theme.dart';
 import 'package:lazurite/features/auth/bloc/auth_bloc.dart';
+import 'package:lazurite/features/settings/bloc/settings_cubit.dart';
+import 'package:lazurite/features/settings/bloc/settings_state.dart';
 import 'package:lazurite/features/auth/presentation/login_screen.dart';
 import 'package:lazurite/features/typeahead/data/typeahead_repository.dart';
 import 'package:lazurite/features/typeahead/data/typeahead_result.dart';
@@ -11,13 +14,25 @@ import 'package:mocktail/mocktail.dart';
 
 class MockAuthBloc extends MockBloc<AuthEvent, AuthState> implements AuthBloc {}
 
+class MockSettingsCubit extends MockCubit<SettingsState> implements SettingsCubit {}
+
 void main() {
   late MockAuthBloc authBloc;
+  late MockSettingsCubit settingsCubit;
 
   setUp(() {
     authBloc = MockAuthBloc();
+    settingsCubit = MockSettingsCubit();
     when(() => authBloc.state).thenReturn(const AuthState.unauthenticated());
     whenListen(authBloc, const Stream<AuthState>.empty(), initialState: const AuthState.unauthenticated());
+    const settingsState = SettingsState(
+      themePalette: AppThemePalette.oxocarbon,
+      themeVariant: AppThemeVariant.dark,
+      useSystemTheme: false,
+    );
+    when(() => settingsCubit.state).thenReturn(settingsState);
+    whenListen(settingsCubit, const Stream<SettingsState>.empty(), initialState: settingsState);
+    when(() => settingsCubit.setAppViewProvider(any())).thenAnswer((_) async {});
   });
 
   Widget buildSubject() {
@@ -29,8 +44,11 @@ void main() {
       routes: [
         GoRoute(
           path: '/login',
-          builder: (context, state) => BlocProvider<AuthBloc>.value(
-            value: authBloc,
+          builder: (context, state) => MultiBlocProvider(
+            providers: [
+              BlocProvider<AuthBloc>.value(value: authBloc),
+              BlocProvider<SettingsCubit>.value(value: settingsCubit),
+            ],
             child: LoginScreen(typeaheadRepository: typeaheadRepository),
           ),
         ),
@@ -102,8 +120,11 @@ void main() {
       routes: [
         GoRoute(
           path: '/login',
-          builder: (context, state) => BlocProvider<AuthBloc>.value(
-            value: authBloc,
+          builder: (context, state) => MultiBlocProvider(
+            providers: [
+              BlocProvider<AuthBloc>.value(value: authBloc),
+              BlocProvider<SettingsCubit>.value(value: settingsCubit),
+            ],
             child: LoginScreen(typeaheadRepository: typeaheadRepository),
           ),
         ),
@@ -124,6 +145,20 @@ void main() {
 
     verify(() => authBloc.add(const OAuthLoginRequested(handle: 'river.bsky.social'))).called(1);
   });
+
+  testWidgets('persists selected provider before triggering OAuth login', (tester) async {
+    await tester.pumpWidget(buildSubject());
+    await tester.pumpAndSettle();
+
+    await tester.enterText(find.byType(TextFormField).first, 'river.bsky.social');
+    await tester.tap(find.text('Continue'));
+    await tester.pumpAndSettle();
+
+    verifyInOrder([
+      () => settingsCubit.setAppViewProvider('bluesky'),
+      () => authBloc.add(const OAuthLoginRequested(handle: 'river.bsky.social')),
+    ]);
+  });
 }
 
 class _FakeTypeaheadRepository extends TypeaheadRepository {
diff --git a/test/features/settings/bloc/settings_cubit_test.dart b/test/features/settings/bloc/settings_cubit_test.dart
index 8fd232f..c9f55d7 100644
--- a/test/features/settings/bloc/settings_cubit_test.dart
+++ b/test/features/settings/bloc/settings_cubit_test.dart
@@ -28,6 +28,7 @@ void main() {
       expect(cubit.state.animationsEnabled, true);
       expect(cubit.state.simulateOffline, false);
       expect(cubit.state.threadAutoCollapseDepth, isNull);
+      expect(cubit.state.appViewProvider, 'bluesky');
     });
 
     test('accepts initial values via constructor', () {
@@ -88,7 +89,8 @@ void main() {
             .having((s) => s.animationsEnabled, 'animationsEnabled', true)
             .having((s) => s.simulateOffline, 'simulateOffline', false)
             .having((s) => s.threadAutoCollapseDepth, 'threadAutoCollapseDepth', isNull)
-            .having((s) => s.typeaheadProvider, 'typeaheadProvider', 'bluesky'),
+            .having((s) => s.typeaheadProvider, 'typeaheadProvider', 'bluesky')
+            .having((s) => s.appViewProvider, 'appViewProvider', 'bluesky'),
       ],
     );
 
@@ -305,5 +307,25 @@ void main() {
       act: (cubit) => cubit.loadSettings(),
       expect: () => [isA<SettingsState>().having((s) => s.typeaheadProvider, 'typeaheadProvider', 'community')],
     );
+
+    blocTest<SettingsCubit, SettingsState>(
+      'setAppViewProvider normalizes and persists provider key',
+      build: () => SettingsCubit(database: database),
+      act: (cubit) => cubit.setAppViewProvider(' BlackSky '),
+      expect: () => [isA<SettingsState>().having((s) => s.appViewProvider, 'appViewProvider', 'blacksky')],
+      verify: (_) async {
+        expect(await database.getSetting('appview_provider'), 'blacksky');
+      },
+    );
+
+    blocTest<SettingsCubit, SettingsState>(
+      'loadSettings falls back to default app view provider for invalid persisted value',
+      build: () => SettingsCubit(database: database),
+      setUp: () async {
+        await database.setSetting('appview_provider', 'unknown-provider');
+      },
+      act: (cubit) => cubit.loadSettings(),
+      expect: () => [isA<SettingsState>().having((s) => s.appViewProvider, 'appViewProvider', 'bluesky')],
+    );
   });
 }
diff --git a/test/features/settings/bloc/settings_state_test.dart b/test/features/settings/bloc/settings_state_test.dart
index e0ffc03..3e2320c 100644
--- a/test/features/settings/bloc/settings_state_test.dart
+++ b/test/features/settings/bloc/settings_state_test.dart
@@ -148,6 +148,7 @@ void main() {
         animationsEnabled: false,
         simulateOffline: true,
         threadAutoCollapseDepth: 3,
+        appViewProvider: 'blacksky',
       );
 
       expect(updated.themePalette, AppThemePalette.nord);
@@ -157,6 +158,7 @@ void main() {
       expect(updated.animationsEnabled, false);
       expect(updated.simulateOffline, true);
       expect(updated.threadAutoCollapseDepth, 3);
+      expect(updated.appViewProvider, 'blacksky');
       expect(original.themePalette, AppThemePalette.oxocarbon);
     });
 
@@ -180,6 +182,7 @@ void main() {
       expect(updated.animationsEnabled, false);
       expect(updated.simulateOffline, true);
       expect(updated.threadAutoCollapseDepth, 4);
+      expect(updated.appViewProvider, 'bluesky');
     });
 
     test('copyWith can clear threadAutoCollapseDepth', () {
@@ -213,6 +216,7 @@ void main() {
       expect(state.props, contains(false));
       expect(state.props, contains(true));
       expect(state.props, contains(6));
+      expect(state.props, contains('bluesky'));
     });
 
     test('defaults feedLayout to card', () {
@@ -250,5 +254,14 @@ void main() {
       );
       expect(state.threadAutoCollapseDepth, isNull);
     });
+
+    test('defaults appViewProvider to bluesky', () {
+      const state = SettingsState(
+        themePalette: AppThemePalette.oxocarbon,
+        themeVariant: AppThemeVariant.dark,
+        useSystemTheme: false,
+      );
+      expect(state.appViewProvider, 'bluesky');
+    });
   });
 }