Add freeform tag search and viewer sort for live lists.

Helix cannot filter by tags or sort ascending; use Twitch GQL for Search→Tags→streams and Most/Fewest viewers on Top, category, and tag screens.

Co-authored-by: Cursor <cursoragent@cursor.com>

DESIGN.md

@@ -36,6 +36,15 @@ Browser vaft hooks `Worker`/`fetch` and rewrites m3u8. Frosty’s native player
 - Third-party proxies
 - HLS segment stripping inside `better_native_video_player` (unless smoke tests demand it)
 
+## Tags + viewer sort (v5.2.2+)
+
+Helix cannot filter by freeform tags or sort ascending. GQL covers both:
+
+- Search: `SearchFreeformTags` → tap → `TagStreams` (`streams` + `freeformTags`)
+- Sort: Top (asc), category (`game.streams`), tag — `VIEWER_COUNT` / `VIEWER_COUNT_ASC` via `StreamSortButton`
+
+Key code: `lib/apis/twitch_gql_api.dart`, `lib/screens/home/search/`, `lib/widgets/stream_sort_button.dart`, `ListStore` / `ListType.tag`.
+
 ## Build
 
 Flutter **3.47.0** (pinned in `pubspec.yaml`). Local SDK: `/home/yuna/.local/flutter-3.47.0`.

lib/apis/twitch_gql_api.dart

@@ -5,14 +5,47 @@ import 'package:flutter/foundation.dart';
 import 'package:frosty/apis/base_api_client.dart';
 import 'package:frosty/constants.dart';
 import 'package:frosty/models/playback_access_token.dart';
+import 'package:frosty/models/stream.dart';
 
-/// Twitch GQL API client for fetching playback access tokens.
+/// Viewer sort for GQL directory / tag stream lists.
+enum StreamViewerSort {
+  viewersDesc,
+  viewersAsc;
+
+  String get gqlValue => switch (this) {
+    StreamViewerSort.viewersDesc => 'VIEWER_COUNT',
+    StreamViewerSort.viewersAsc => 'VIEWER_COUNT_ASC',
+  };
+}
+
+/// Twitch GQL API client for playback tokens and directory queries
+/// (freeform tags + sorted streams) that Helix does not expose.
 ///
 /// Uses the Twitch web client ID (not the app's registered client ID)
 /// since the GQL endpoint requires it.
 class TwitchGqlApi extends BaseApiClient {
   TwitchGqlApi(Dio dio) : super(dio, 'https://gql.twitch.tv');
 
+  static const _gqlHeaders = <String, String>{
+    'Client-ID': twitchGqlClientId,
+    'Content-Type': 'application/json',
+  };
+
+  Future<JsonMap> _gql(Map<String, Object?> body) async {
+    final response = await post<JsonMap>(
+      '/gql',
+      data: body,
+      headers: _gqlHeaders,
+    );
+    final errors = response['errors'];
+    if (errors is List && errors.isNotEmpty && response['data'] == null) {
+      final message = (errors.first as JsonMap)['message'] as String? ??
+          'Twitch GQL error';
+      throw ApiException(message);
+    }
+    return response;
+  }
+
   /// Browser-consistent User-Agent for playback-related requests. Twitch has
   /// rejected access-token requests with non-browser UAs before
   /// (streamlink#6574); sending one consistent with the web client ID and
@@ -140,4 +173,138 @@ class TwitchGqlApi extends BaseApiClient {
     }
     return buffer.toString();
   }
+
+  /// Freeform tag name suggestions for search-as-you-type.
+  Future<List<String>> searchFreeformTags({
+    required String query,
+    int first = 20,
+  }) async {
+    if (query.trim().isEmpty) return const [];
+
+    final response = await _gql({
+      'operationName': 'SearchFreeformTags',
+      'query':
+          r'query SearchFreeformTags($query: String!, $first: Int) {'
+          r' searchFreeformTags(userQuery: $query, first: $first) {'
+          r' edges { node { tagName } } } }',
+      'variables': {'query': query, 'first': first},
+    });
+
+    final edges =
+        (((response['data'] as JsonMap?)?['searchFreeformTags']
+                as JsonMap?)?['edges']
+            as List?) ??
+        const [];
+
+    return edges
+        .map((edge) {
+          final node = (edge as JsonMap)['node'] as JsonMap?;
+          return node?['tagName'] as String?;
+        })
+        .whereType<String>()
+        .toList();
+  }
+
+  /// Live streams matching optional [freeformTags], sorted by viewer count.
+  Future<StreamsTwitch> getStreams({
+    List<String>? freeformTags,
+    StreamViewerSort sort = StreamViewerSort.viewersDesc,
+    String? cursor,
+    int first = 30,
+  }) async {
+    final response = await _gql({
+      'operationName': 'FrostyTopStreams',
+      'query':
+          r'query FrostyTopStreams($first: Int, $after: Cursor, $tags: [String!], $sort: StreamSort) {'
+          r' streams(first: $first, after: $after, options: { sort: $sort, freeformTags: $tags }) {'
+          r' edges { cursor node {'
+          r' id title viewersCount createdAt'
+          r' game { id name }'
+          r' broadcaster { id login displayName }'
+          r' } } pageInfo { hasNextPage } } }',
+      'variables': {
+        'first': first,
+        'after': cursor,
+        'tags': freeformTags,
+        'sort': sort.gqlValue,
+      },
+    });
+
+    final connection =
+        (response['data'] as JsonMap?)?['streams'] as JsonMap? ?? const {};
+    return _streamsFromConnection(connection);
+  }
+
+  /// Live streams under a category/game, with viewer sort (Helix has no asc).
+  Future<StreamsTwitch> getGameStreams({
+    required String gameId,
+    StreamViewerSort sort = StreamViewerSort.viewersDesc,
+    String? cursor,
+    int first = 30,
+  }) async {
+    final response = await _gql({
+      'operationName': 'FrostyGameStreams',
+      'query':
+          r'query FrostyGameStreams($id: ID!, $first: Int, $after: Cursor, $sort: StreamSort) {'
+          r' game(id: $id) { streams(first: $first, after: $after, options: { sort: $sort }) {'
+          r' edges { cursor node {'
+          r' id title viewersCount createdAt'
+          r' game { id name }'
+          r' broadcaster { id login displayName }'
+          r' } } pageInfo { hasNextPage } } } }',
+      'variables': {
+        'id': gameId,
+        'first': first,
+        'after': cursor,
+        'sort': sort.gqlValue,
+      },
+    });
+
+    final game = (response['data'] as JsonMap?)?['game'] as JsonMap?;
+    if (game == null) {
+      return const StreamsTwitch([], {});
+    }
+    return _streamsFromConnection(game['streams'] as JsonMap? ?? const {});
+  }
+
+  StreamsTwitch _streamsFromConnection(JsonMap connection) {
+    final edges = (connection['edges'] as List?) ?? const [];
+    final pageInfo = connection['pageInfo'] as JsonMap?;
+    final hasNext = pageInfo?['hasNextPage'] as bool? ?? false;
+
+    final streams = <StreamTwitch>[];
+    String? nextCursor;
+
+    for (final edge in edges) {
+      final edgeMap = edge as JsonMap;
+      nextCursor = edgeMap['cursor'] as String?;
+      final node = edgeMap['node'] as JsonMap?;
+      if (node == null) continue;
+      streams.add(_streamFromNode(node));
+    }
+
+    return StreamsTwitch(
+      streams,
+      hasNext && nextCursor != null ? {'cursor': nextCursor} : const {},
+    );
+  }
+
+  StreamTwitch _streamFromNode(JsonMap node) {
+    final broadcaster = node['broadcaster'] as JsonMap? ?? const {};
+    final game = node['game'] as JsonMap? ?? const {};
+    final login = broadcaster['login'] as String? ?? '';
+
+    return StreamTwitch(
+      broadcaster['id'] as String? ?? '',
+      login,
+      broadcaster['displayName'] as String? ?? login,
+      game['id'] as String? ?? '',
+      game['name'] as String? ?? '',
+      node['title'] as String? ?? '',
+      (node['viewersCount'] as num?)?.toInt() ?? 0,
+      node['createdAt'] as String? ?? '',
+      // Helix-style placeholder so existing thumbnail widgets keep working.
+      'https://static-cdn.jtvnw.net/previews-ttv/live_user_$login-{width}x{height}.jpg',
+    );
+  }
 }

lib/screens/channel/video/native_video_store.g.dart

@@ -67,9 +67,6 @@ mixin _$NativeVideoStore on NativeVideoStoreBase, Store {
     return super._blockingAds;
   }
 
-  @override
-  bool get isBlockingAds => blockingAds;
-
   @override
   bool get _blockingAds => blockingAds;
 

lib/screens/home/search/search.dart

@@ -2,8 +2,10 @@ import 'package:collection/collection.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_mobx/flutter_mobx.dart';
 import 'package:frosty/apis/twitch_api.dart';
+import 'package:frosty/apis/twitch_gql_api.dart';
 import 'package:frosty/screens/home/search/search_results_categories.dart';
 import 'package:frosty/screens/home/search/search_results_channels.dart';
+import 'package:frosty/screens/home/search/search_results_tags.dart';
 import 'package:frosty/screens/home/search/search_store.dart';
 import 'package:frosty/screens/home/stream_list/streams_list.dart';
 import 'package:frosty/screens/settings/stores/auth_store.dart';
@@ -31,6 +33,7 @@ class _SearchState extends State<Search> {
   late final _searchStore = SearchStore(
     authStore: context.read<AuthStore>(),
     twitchApi: context.read<TwitchApi>(),
+    twitchGqlApi: context.read<TwitchGqlApi>(),
   );
 
   @override
@@ -171,6 +174,20 @@ class _SearchState extends State<Search> {
                       ),
                     ),
                     SearchResultsCategories(searchStore: _searchStore),
+                    SliverToBoxAdapter(
+                      child: Builder(
+                        builder: (context) => SectionHeader(
+                          'Tags',
+                          padding: EdgeInsets.fromLTRB(
+                            16 + MediaQuery.of(context).padding.left,
+                            8,
+                            16 + MediaQuery.of(context).padding.right,
+                            8,
+                          ),
+                        ),
+                      ),
+                    ),
+                    SearchResultsTags(searchStore: _searchStore),
                     // Add padding for bottom navigation bar
                     const SliverBottomPadding(),
                   ],
@@ -204,7 +221,7 @@ class _SearchState extends State<Search> {
                         onChanged: _searchStore.onSearchTextChanged,
                         decoration: InputDecoration(
                           prefixIcon: const Icon(Icons.search_rounded),
-                          hintText: 'Search channels or categories',
+                          hintText: 'Search channels, categories, or tags',
                           suffixIcon:
                               _searchStore.textFieldFocusNode.hasFocus ||
                                   _searchStore.searchText.isNotEmpty

lib/screens/home/search/search_results_tags.dart

@@ -0,0 +1,97 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_mobx/flutter_mobx.dart';
+import 'package:frosty/screens/home/search/search_store.dart';
+import 'package:frosty/screens/home/search/tag_streams.dart';
+import 'package:frosty/widgets/alert_message.dart';
+import 'package:frosty/widgets/skeleton_loader.dart';
+import 'package:mobx/mobx.dart';
+
+class SearchResultsTags extends StatelessWidget {
+  final SearchStore searchStore;
+
+  const SearchResultsTags({super.key, required this.searchStore});
+
+  @override
+  Widget build(BuildContext context) {
+    return Observer(
+      builder: (context) {
+        final future = searchStore.tagFuture;
+
+        if (future == null) {
+          if (searchStore.isSearching) {
+            return _tagSkeletons();
+          }
+          return const SliverToBoxAdapter(child: SizedBox.shrink());
+        }
+
+        switch (future.status) {
+          case FutureStatus.pending:
+            return _tagSkeletons();
+          case FutureStatus.rejected:
+            return const SliverToBoxAdapter(
+              child: SizedBox(
+                height: 100.0,
+                child: AlertMessage(
+                  message: 'Unable to load tags',
+                  vertical: true,
+                ),
+              ),
+            );
+          case FutureStatus.fulfilled:
+            final List<String> tags = future.result as List<String>? ?? const [];
+
+            if (tags.isEmpty) {
+              return const SliverToBoxAdapter(
+                child: SizedBox(
+                  height: 100.0,
+                  child: AlertMessage(
+                    message: 'No matching tags',
+                    vertical: true,
+                  ),
+                ),
+              );
+            }
+
+            return SliverList.builder(
+              itemCount: tags.length,
+              itemBuilder: (context, index) {
+                final tag = tags[index];
+                return ListTile(
+                  leading: const Icon(Icons.tag_rounded),
+                  title: Text(tag),
+                  onTap: () {
+                    Navigator.push(
+                      context,
+                      MaterialPageRoute(
+                        settings: const RouteSettings(
+                          name: TagStreams.routeName,
+                        ),
+                        builder: (context) => TagStreams(tagName: tag),
+                      ),
+                    );
+                  },
+                );
+              },
+            );
+        }
+      },
+    );
+  }
+
+  Widget _tagSkeletons() {
+    return SliverList.builder(
+      itemCount: 4,
+      itemBuilder: (context, index) => ListTile(
+        leading: SkeletonLoader(
+          width: 24,
+          height: 24,
+          borderRadius: BorderRadius.circular(4),
+        ),
+        title: SkeletonLoader(
+          height: 16,
+          borderRadius: BorderRadius.circular(4),
+        ),
+      ),
+    );
+  }
+}

lib/screens/home/search/search_store.dart

@@ -2,6 +2,7 @@ import 'dart:async';
 
 import 'package:flutter/widgets.dart';
 import 'package:frosty/apis/twitch_api.dart';
+import 'package:frosty/apis/twitch_gql_api.dart';
 import 'package:frosty/models/category.dart';
 import 'package:frosty/models/channel.dart';
 import 'package:frosty/screens/settings/stores/auth_store.dart';
@@ -17,6 +18,8 @@ abstract class SearchStoreBase with Store {
 
   final TwitchApi twitchApi;
 
+  final TwitchGqlApi twitchGqlApi;
+
   final textEditingController = TextEditingController();
 
   final textFieldFocusNode = FocusNode();
@@ -40,7 +43,14 @@ abstract class SearchStoreBase with Store {
   @readonly
   ObservableFuture<CategoriesTwitch?>? _categoryFuture;
 
-  SearchStoreBase({required this.authStore, required this.twitchApi}) {
+  @readonly
+  ObservableFuture<List<String>>? _tagFuture;
+
+  SearchStoreBase({
+    required this.authStore,
+    required this.twitchApi,
+    required this.twitchGqlApi,
+  }) {
     init();
   }
 
@@ -75,6 +85,7 @@ abstract class SearchStoreBase with Store {
       _isSearching = false;
       _channelFuture = null;
       _categoryFuture = null;
+      _tagFuture = null;
       return;
     }
 
@@ -127,6 +138,8 @@ abstract class SearchStoreBase with Store {
       }
       return categories;
     }).asObservable();
+
+    _tagFuture = twitchGqlApi.searchFreeformTags(query: query).asObservable();
   }
 
   /// Find a specific channel provided the [query].

lib/screens/home/search/search_store.g.dart

@@ -109,6 +109,26 @@ mixin _$SearchStore on SearchStoreBase, Store {
     });
   }
 
+  late final _$_tagFutureAtom = Atom(
+    name: 'SearchStoreBase._tagFuture',
+    context: context,
+  );
+
+  ObservableFuture<List<String>>? get tagFuture {
+    _$_tagFutureAtom.reportRead();
+    return super._tagFuture;
+  }
+
+  @override
+  ObservableFuture<List<String>>? get _tagFuture => tagFuture;
+
+  @override
+  set _tagFuture(ObservableFuture<List<String>>? value) {
+    _$_tagFutureAtom.reportWrite(value, super._tagFuture, () {
+      super._tagFuture = value;
+    });
+  }
+
   late final _$initAsyncAction = AsyncAction(
     'SearchStoreBase.init',
     context: context,

lib/screens/home/search/tag_streams.dart

@@ -0,0 +1,83 @@
+import 'package:flutter/material.dart';
+import 'package:frosty/apis/twitch_gql_api.dart';
+import 'package:frosty/screens/home/stream_list/stream_list_store.dart';
+import 'package:frosty/screens/home/stream_list/streams_list.dart';
+import 'package:frosty/widgets/blurred_container.dart';
+import 'package:frosty/widgets/stream_sort_button.dart';
+
+/// Streams matching a freeform tag (search → tap tag).
+class TagStreams extends StatefulWidget {
+  static const routeName = 'TagStreams';
+
+  final String tagName;
+
+  const TagStreams({super.key, required this.tagName});
+
+  @override
+  State<TagStreams> createState() => _TagStreamsState();
+}
+
+class _TagStreamsState extends State<TagStreams> {
+  var _sortOrder = StreamViewerSort.viewersDesc;
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = Theme.of(context);
+
+    return Scaffold(
+      backgroundColor: theme.scaffoldBackgroundColor,
+      extendBody: true,
+      extendBodyBehindAppBar: true,
+      body: Stack(
+        children: [
+          Positioned.fill(
+            child: StreamsList(
+              key: ValueKey(_sortOrder),
+              listType: ListType.tag,
+              freeformTag: widget.tagName,
+              sortOrder: _sortOrder,
+              showJumpButton: true,
+            ),
+          ),
+          Positioned(
+            top: 0,
+            left: 0,
+            right: 0,
+            child: BlurredContainer(
+              gradientDirection: GradientDirection.up,
+              padding: EdgeInsets.only(
+                top: MediaQuery.of(context).padding.top,
+                left: MediaQuery.of(context).padding.left,
+                right: MediaQuery.of(context).padding.right,
+              ),
+              child: SizedBox(
+                height: kToolbarHeight,
+                child: Row(
+                  children: [
+                    IconButton(
+                      tooltip: 'Back',
+                      icon: Icon(Icons.adaptive.arrow_back_rounded),
+                      onPressed: Navigator.of(context).pop,
+                    ),
+                    Expanded(
+                      child: Text(
+                        widget.tagName,
+                        style: theme.textTheme.titleLarge,
+                        maxLines: 1,
+                        overflow: TextOverflow.ellipsis,
+                      ),
+                    ),
+                    StreamSortButton(
+                      sortOrder: _sortOrder,
+                      onChanged: (order) => setState(() => _sortOrder = order),
+                    ),
+                  ],
+                ),
+              ),
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+}

lib/screens/home/stream_list/stream_list_store.dart

@@ -3,6 +3,7 @@ import 'dart:io';
 import 'package:flutter/widgets.dart';
 import 'package:frosty/apis/base_api_client.dart';
 import 'package:frosty/apis/twitch_api.dart';
+import 'package:frosty/apis/twitch_gql_api.dart';
 import 'package:frosty/models/category.dart';
 import 'package:frosty/models/followed_channel.dart';
 import 'package:frosty/models/stream.dart';
@@ -23,12 +24,22 @@ abstract class ListStoreBase with Store {
   /// Twitch API service class for making requests.
   final TwitchApi twitchApi;
 
+  /// GQL client for tag streams and ascending viewer sort (Helix has neither).
+  final TwitchGqlApi? twitchGqlApi;
+
   /// The type of list that this store is handling.
   final ListType listType;
 
   /// The category id to use when fetching streams if the [listType] is [ListType.category].
   final String? categoryId;
 
+  /// Freeform tag name when [listType] is [ListType.tag].
+  final String? freeformTag;
+
+  /// Viewer sort for top / category / tag lists.
+  @observable
+  StreamViewerSort sortOrder;
+
   /// The scroll controller used for handling scroll to top (if provided).
   /// If provided, will use the [ScrollToTop] widget to scroll to the top of the list instead of the bottom tab bar.
   final ScrollController? scrollController;
@@ -151,7 +162,10 @@ abstract class ListStoreBase with Store {
     required this.settingsStore,
     required this.twitchApi,
     required this.listType,
+    this.twitchGqlApi,
     this.categoryId,
+    this.freeformTag,
+    this.sortOrder = StreamViewerSort.viewersDesc,
     this.scrollController,
   }) {
     if (scrollController != null) {
@@ -213,13 +227,38 @@ abstract class ListStoreBase with Store {
           );
           break;
         case ListType.top:
+          // Helix is always viewer-desc; ascending needs GQL.
+          if (sortOrder == StreamViewerSort.viewersAsc &&
+              twitchGqlApi != null) {
+            newStreams = await twitchGqlApi!.getStreams(
+              sort: sortOrder,
+              cursor: _streamsCursor,
+            );
+          } else {
             newStreams = await twitchApi.getTopStreams(cursor: _streamsCursor);
+          }
           break;
         case ListType.category:
+          if (sortOrder == StreamViewerSort.viewersAsc &&
+              twitchGqlApi != null) {
+            newStreams = await twitchGqlApi!.getGameStreams(
+              gameId: categoryId!,
+              sort: sortOrder,
+              cursor: _streamsCursor,
+            );
+          } else {
             newStreams = await twitchApi.getStreamsUnderCategory(
               gameId: categoryId!,
               cursor: _streamsCursor,
             );
+          }
+          break;
+        case ListType.tag:
+          newStreams = await twitchGqlApi!.getStreams(
+            freeformTags: [freeformTag!],
+            sort: sortOrder,
+            cursor: _streamsCursor,
+          );
           break;
       }
 
@@ -245,6 +284,14 @@ abstract class ListStoreBase with Store {
     _isAllStreamsLoading = false;
   }
 
+  /// Changes viewer sort and reloads from the first page.
+  @action
+  Future<void> setSortOrder(StreamViewerSort order) async {
+    if (sortOrder == order) return;
+    sortOrder = order;
+    await refreshStreams();
+  }
+
   @action
   Future<void> getPinnedStreams() async {
     if (settingsStore.pinnedChannelIds.isEmpty) {
@@ -359,4 +406,5 @@ abstract class ListStoreBase with Store {
 /// [ListType.followed] is the list of streams that the user is following.
 /// [ListType.top] is the list of top streams.
 /// [ListType.category] is the list of streams under a category.
-enum ListType { followed, top, category }
+/// [ListType.tag] is the list of streams matching a freeform tag (GQL).
+enum ListType { followed, top, category, tag }

lib/screens/home/stream_list/stream_list_store.g.dart

@@ -56,6 +56,24 @@ mixin _$ListStore on ListStoreBase, Store {
         name: 'ListStoreBase.offlineChannels',
       )).value;
 
+  late final _$sortOrderAtom = Atom(
+    name: 'ListStoreBase.sortOrder',
+    context: context,
+  );
+
+  @override
+  StreamViewerSort get sortOrder {
+    _$sortOrderAtom.reportRead();
+    return super.sortOrder;
+  }
+
+  @override
+  set sortOrder(StreamViewerSort value) {
+    _$sortOrderAtom.reportWrite(value, super.sortOrder, () {
+      super.sortOrder = value;
+    });
+  }
+
   late final _$_allStreamsAtom = Atom(
     name: 'ListStoreBase._allStreams',
     context: context,
@@ -302,6 +320,16 @@ mixin _$ListStore on ListStoreBase, Store {
     return _$getStreamsAsyncAction.run(() => super.getStreams());
   }
 
+  late final _$setSortOrderAsyncAction = AsyncAction(
+    'ListStoreBase.setSortOrder',
+    context: context,
+  );
+
+  @override
+  Future<void> setSortOrder(StreamViewerSort order) {
+    return _$setSortOrderAsyncAction.run(() => super.setSortOrder(order));
+  }
+
   late final _$getPinnedStreamsAsyncAction = AsyncAction(
     'ListStoreBase.getPinnedStreams',
     context: context,
@@ -349,6 +377,7 @@ mixin _$ListStore on ListStoreBase, Store {
   @override
   String toString() {
     return '''
+sortOrder: ${sortOrder},
 showJumpButton: ${showJumpButton},
 isOfflineChannelsExpanded: ${isOfflineChannelsExpanded},
 hasMore: ${hasMore},

lib/screens/home/stream_list/streams_list.dart

@@ -2,6 +2,7 @@ import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_mobx/flutter_mobx.dart';
 import 'package:frosty/apis/twitch_api.dart';
+import 'package:frosty/apis/twitch_gql_api.dart';
 import 'package:frosty/models/stream.dart';
 import 'package:frosty/screens/home/stream_list/large_stream_card.dart';
 import 'package:frosty/screens/home/stream_list/offline_channel_card.dart';
@@ -25,6 +26,12 @@ class StreamsList extends StatefulWidget {
 
   final String? categoryId;
 
+  /// Freeform tag when [listType] is [ListType.tag].
+  final String? freeformTag;
+
+  /// Viewer sort for top / category / tag lists.
+  final StreamViewerSort sortOrder;
+
   /// The scroll controller to use for scroll to top functionality.
   final ScrollController? scrollController;
 
@@ -34,6 +41,8 @@ class StreamsList extends StatefulWidget {
     super.key,
     required this.listType,
     this.categoryId,
+    this.freeformTag,
+    this.sortOrder = StreamViewerSort.viewersDesc,
     this.scrollController,
     this.showJumpButton = false,
   });
@@ -63,8 +72,11 @@ class _StreamsListState extends State<StreamsList>
       authStore: context.read<AuthStore>(),
       settingsStore: context.read<SettingsStore>(),
       twitchApi: context.read<TwitchApi>(),
+      twitchGqlApi: context.read<TwitchGqlApi>(),
       listType: widget.listType,
       categoryId: widget.categoryId,
+      freeformTag: widget.freeformTag,
+      sortOrder: widget.sortOrder,
       scrollController: widget.scrollController ?? _scrollController,
     );
   }
@@ -95,6 +107,8 @@ class _StreamsListState extends State<StreamsList>
         ? kToolbarHeight
         : widget.listType == ListType.category
         ? kToolbarHeight + 122
+        : widget.listType == ListType.tag
+        ? kToolbarHeight
         : 0.0;
 
     final topPadding = MediaQuery.of(context).padding.top + extraTopPadding;
@@ -209,9 +223,12 @@ class _StreamsListState extends State<StreamsList>
               );
             } else {
               statusWidget = AlertMessage(
-                message: widget.listType == ListType.followed
-                    ? 'No followed streams'
-                    : 'No top streams',
+                message: switch (widget.listType) {
+                  ListType.followed => 'No followed streams',
+                  ListType.tag => 'No streams with this tag',
+                  ListType.category => 'No streams in this category',
+                  ListType.top => 'No top streams',
+                },
                 vertical: true,
               );
             }

lib/screens/home/top/categories/category_streams.dart

@@ -1,6 +1,7 @@
 import 'package:flutter/material.dart';
 import 'package:flutter_mobx/flutter_mobx.dart';
 import 'package:frosty/apis/twitch_api.dart';
+import 'package:frosty/apis/twitch_gql_api.dart';
 import 'package:frosty/constants.dart';
 import 'package:frosty/screens/home/stream_list/stream_list_store.dart';
 import 'package:frosty/screens/home/stream_list/streams_list.dart';
@@ -9,6 +10,7 @@ import 'package:frosty/screens/settings/stores/settings_store.dart';
 import 'package:frosty/widgets/blurred_container.dart';
 import 'package:frosty/widgets/frosty_cached_network_image.dart';
 import 'package:frosty/widgets/skeleton_loader.dart';
+import 'package:frosty/widgets/stream_sort_button.dart';
 import 'package:provider/provider.dart';
 
 /// A widget that displays a list of streams under the provided [categoryId].
@@ -25,11 +27,14 @@ class CategoryStreams extends StatefulWidget {
 }
 
 class _CategoryStreamsState extends State<CategoryStreams> {
+  var _sortOrder = StreamViewerSort.viewersDesc;
+
   late final _listStore = ListStore(
     listType: ListType.category,
     categoryId: widget.categoryId,
     authStore: context.read<AuthStore>(),
     twitchApi: context.read<TwitchApi>(),
+    twitchGqlApi: context.read<TwitchGqlApi>(),
     settingsStore: context.read<SettingsStore>(),
   );
 
@@ -46,8 +51,10 @@ class _CategoryStreamsState extends State<CategoryStreams> {
           // Stream list content behind the pinned elements
           Positioned.fill(
             child: StreamsList(
+              key: ValueKey(_sortOrder),
               listType: ListType.category,
               categoryId: widget.categoryId,
+              sortOrder: _sortOrder,
               showJumpButton: true,
             ),
           ),
@@ -76,6 +83,12 @@ class _CategoryStreamsState extends State<CategoryStreams> {
                           icon: Icon(Icons.adaptive.arrow_back_rounded),
                           onPressed: Navigator.of(context).pop,
                         ),
+                        const Spacer(),
+                        StreamSortButton(
+                          sortOrder: _sortOrder,
+                          onChanged: (order) =>
+                              setState(() => _sortOrder = order),
+                        ),
                       ],
                     ),
                   ),
@@ -108,8 +121,7 @@ class _CategoryStreamsState extends State<CategoryStreams> {
                               ),
                               Expanded(
                                 child: Column(
-                                    crossAxisAlignment:
-                                        CrossAxisAlignment.start,
+                                  crossAxisAlignment: CrossAxisAlignment.start,
                                   spacing: 8,
                                   children: [
                                     SkeletonLoader(

lib/screens/home/top/top.dart

@@ -1,9 +1,11 @@
 import 'package:flutter/material.dart';
+import 'package:frosty/apis/twitch_gql_api.dart';
 import 'package:frosty/screens/home/home_store.dart';
 import 'package:frosty/screens/home/stream_list/stream_list_store.dart';
 import 'package:frosty/screens/home/stream_list/streams_list.dart';
 import 'package:frosty/screens/home/top/categories/categories.dart';
 import 'package:frosty/widgets/blurred_container.dart';
+import 'package:frosty/widgets/stream_sort_button.dart';
 
 class TopSection extends StatefulWidget {
   final HomeStore homeStore;
@@ -17,17 +19,21 @@ class TopSection extends StatefulWidget {
 class _TopSectionState extends State<TopSection>
     with SingleTickerProviderStateMixin {
   late final _tabBarController = TabController(length: 2, vsync: this);
+  var _sortOrder = StreamViewerSort.viewersDesc;
 
   @override
   void initState() {
     super.initState();
-    _tabBarController.addListener(
-      () => widget.homeStore.topSectionCurrentIndex = _tabBarController.index,
-    );
+    _tabBarController.addListener(() {
+      widget.homeStore.topSectionCurrentIndex = _tabBarController.index;
+      setState(() {});
+    });
   }
 
   @override
   Widget build(BuildContext context) {
+    final showSort = _tabBarController.index == 0;
+
     return Stack(
       children: [
         Positioned.fill(
@@ -35,7 +41,9 @@ class _TopSectionState extends State<TopSection>
             controller: _tabBarController,
             children: [
               StreamsList(
+                key: ValueKey(_sortOrder),
                 listType: ListType.top,
+                sortOrder: _sortOrder,
                 scrollController:
                     widget.homeStore.topSectionScrollControllers[0],
               ),
@@ -57,6 +65,9 @@ class _TopSectionState extends State<TopSection>
               left: MediaQuery.of(context).padding.left,
               right: MediaQuery.of(context).padding.right,
             ),
+            child: Row(
+              children: [
+                Expanded(
                   child: TabBar(
                     isScrollable: true,
                     controller: _tabBarController,
@@ -66,6 +77,14 @@ class _TopSectionState extends State<TopSection>
                     ],
                   ),
                 ),
+                if (showSort)
+                  StreamSortButton(
+                    sortOrder: _sortOrder,
+                    onChanged: (order) => setState(() => _sortOrder = order),
+                  ),
+              ],
+            ),
+          ),
         ),
       ],
     );

lib/widgets/stream_sort_button.dart

@@ -0,0 +1,38 @@
+import 'package:flutter/material.dart';
+import 'package:frosty/apis/twitch_gql_api.dart';
+
+/// Toggles viewer-count sort between descending (default) and ascending.
+class StreamSortButton extends StatelessWidget {
+  final StreamViewerSort sortOrder;
+  final ValueChanged<StreamViewerSort> onChanged;
+
+  const StreamSortButton({
+    super.key,
+    required this.sortOrder,
+    required this.onChanged,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    final isAsc = sortOrder == StreamViewerSort.viewersAsc;
+
+    return PopupMenuButton<StreamViewerSort>(
+      tooltip: 'Sort by viewers',
+      icon: Icon(
+        isAsc ? Icons.arrow_upward_rounded : Icons.arrow_downward_rounded,
+      ),
+      initialValue: sortOrder,
+      onSelected: onChanged,
+      itemBuilder: (context) => [
+        const PopupMenuItem(
+          value: StreamViewerSort.viewersDesc,
+          child: Text('Most viewers'),
+        ),
+        const PopupMenuItem(
+          value: StreamViewerSort.viewersAsc,
+          child: Text('Fewest viewers'),
+        ),
+      ],
+    );
+  }
+}

pubspec.yaml

@@ -17,7 +17,7 @@ publish_to: "none" # Remove this line if you wish to publish to pub.dev
 # https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html
 # In Windows, build-name is used as the major, minor, and patch parts
 # of the product and file versions while build-number is used as the build suffix.
-version: 5.2.1+71
+version: 5.2.2+72
 
 environment:
   sdk: ^3.9.0