diff --git a/lib/features/chat/models/chat_message_model.dart b/lib/features/chat/models/chat_message_model.dart
index 4bffd8b7..84c238be 100644
--- a/lib/features/chat/models/chat_message_model.dart
+++ b/lib/features/chat/models/chat_message_model.dart
@@ -31,6 +31,11 @@ abstract class ChatMessageModel with _$ChatMessageModel {
     @JsonKey(name: 'author_id', fromJson: _parseAuthorId) required int authorId,
     @JsonKey(name: 'updated_at', fromJson: _parseUpdatedAt) required DateTime updatedAt,
     @JsonKey(name: 'read_by_to_user', defaultValue: false) required bool isRead,
+    // @deprecated Backend BC-поле. В broadcast (ChatMessageUpdated) оно
+    // recipient-relative и для второго устройства отправителя всегда false,
+    // поэтому решать «моё/не моё» по нему нельзя. Источник истины — authorId:
+    // сравнивайте его со своим user_id (wsManager.userId). Поле оставлено
+    // только для обратной совместимости парсинга.
     @JsonKey(name: 'is_author_message_auth_user') required bool? isCurrentUserAuthor,
     @JsonKey(name: 'room_id') required String? roomId,
     @JsonKey(name: 'type', unknownEnumValue: ChatMessageType.unknown) ChatMessageType? type,
diff --git a/lib/features/chat/presentation/bloc/chats_cubit/chats_cubit.dart b/lib/features/chat/presentation/bloc/chats_cubit/chats_cubit.dart
index 10f91095..d4e421fa 100644
--- a/lib/features/chat/presentation/bloc/chats_cubit/chats_cubit.dart
+++ b/lib/features/chat/presentation/bloc/chats_cubit/chats_cubit.dart
@@ -144,6 +144,9 @@ class ChatsCubit extends Cubit<ChatsState> {
       final json = jsonDecode(data) as Map<String, dynamic>;
       final message = ChatMessageModel.fromJson(json);
 
+      final currentUserId = wsManager.userId;
+      final isOwn = currentUserId != null && message.authorId == currentUserId;
+
       final currentChatRooms = [...state.chatRooms];
 
       bool wasChanged = false;
@@ -151,10 +154,18 @@ class ChatsCubit extends Cubit<ChatsState> {
       final updatedChatRooms = currentChatRooms.map((chatRoom) {
         if (chatRoom.id == message.roomId) {
           wasChanged = true;
-          if (chatRoom.unreadMessagesCount == 0) {
+          // Идемпотентность: повторная доставка того же message.id (реконнект,
+          // доставка по нескольким каналам) не начисляет непрочитанное дважды.
+          final isDuplicate = message.id != 0 && chatRoom.lastMessage?.id == message.id;
+          // Собственное сообщение (второе устройство автора) обновляет
+          // lastMessage, но не создаёт непрочитанное (S3).
+          if (!isOwn && !isDuplicate && chatRoom.unreadMessagesCount == 0) {
             willIncrementUnreadChats = true;
           }
-          return chatRoom.copyWith(lastMessage: message, unreadMessagesCount: chatRoom.unreadMessagesCount + 1);
+          return chatRoom.copyWith(
+            lastMessage: message,
+            unreadMessagesCount: isOwn || isDuplicate ? chatRoom.unreadMessagesCount : chatRoom.unreadMessagesCount + 1,
+          );
         }
         return chatRoom;
       }).toList();
diff --git a/test/features/chat/presentation/bloc/chats_cubit_test.dart b/test/features/chat/presentation/bloc/chats_cubit_test.dart
index c3af3197..a3569618 100644
--- a/test/features/chat/presentation/bloc/chats_cubit_test.dart
+++ b/test/features/chat/presentation/bloc/chats_cubit_test.dart
@@ -1,4 +1,5 @@
 import 'dart:async';
+import 'dart:convert';
 import 'package:eatvio_app/core/enums/base_state.dart';
 import 'package:eatvio_app/core/models/pagination_model.dart';
 import 'package:eatvio_app/core/websockets/ws_manager.dart';
@@ -43,6 +44,39 @@ void main() {
       }
     });
 
+    ChatRoom buildChatRoom(String chatId, {int unread = 0}) {
+      return ChatRoom(
+        id: chatId,
+        lastMessage: null,
+        users: const Users(
+          fromChatUser: ChatUser(id: 1, name: 'User 1', profilePhotoPath: null, profilePhotoUrl: ''),
+          toChatUser: ChatUser(id: 2, name: 'User 2', profilePhotoPath: null, profilePhotoUrl: ''),
+        ),
+        unreadMessagesCount: unread,
+        chosenPlan: null,
+      );
+    }
+
+    ChannelReadEvent socketEvent({required int id, required int authorId, required String roomId}) {
+      return _FakeChannelReadEvent(jsonEncode(<String, dynamic>{
+        'id': id,
+        'data': 'socket message',
+        'media_data': null,
+        'author_id': authorId,
+        'updated_at': DateTime.now().toIso8601String(),
+        'read_by_to_user': false,
+        'is_author_message_auth_user': false,
+        'room_id': roomId,
+      }));
+    }
+
+    Future<StreamController<ChannelReadEvent>> connectToSocketStream() async {
+      final controller = StreamController<ChannelReadEvent>.broadcast();
+      when(mockWsManager.newMessagesStream).thenAnswer((_) => controller.stream);
+      await chatsCubit.connectToWebSocket();
+      return controller;
+    }
+
     test('начальное состояние - initial', () {
       expect(chatsCubit.state, isA<ChatsState>());
       expect(chatsCubit.state.state, BaseState.initial);
@@ -180,6 +214,76 @@ void main() {
       verify(mockWsManager.newMessagesStream).called(1);
     });
 
+    test('_handleNewMessageViaSocket - собственное сообщение обновляет lastMessage без непрочитанного', () async {
+      const chatId = 'chat-id';
+      chatsCubit.emit(ChatsState(state: BaseState.success, chatRooms: [buildChatRoom(chatId)]));
+      when(mockWsManager.userId).thenReturn(42);
+
+      final controller = await connectToSocketStream();
+      controller.add(socketEvent(id: 100, authorId: 42, roomId: chatId));
+      await Future.delayed(const Duration(milliseconds: 100));
+
+      final room = chatsCubit.state.chatRooms.firstWhere((r) => r.id == chatId);
+      expect(room.lastMessage?.id, 100);
+      expect(room.unreadMessagesCount, 0);
+      expect(chatsCubit.state.chatsWithUnreadMessagesCount, 0);
+
+      await controller.close();
+    });
+
+    test('_handleNewMessageViaSocket - чужое сообщение увеличивает непрочитанное', () async {
+      const chatId = 'chat-id';
+      chatsCubit.emit(ChatsState(state: BaseState.success, chatRooms: [buildChatRoom(chatId)]));
+      when(mockWsManager.userId).thenReturn(42);
+
+      final controller = await connectToSocketStream();
+      controller.add(socketEvent(id: 200, authorId: 7, roomId: chatId));
+      await Future.delayed(const Duration(milliseconds: 100));
+
+      final room = chatsCubit.state.chatRooms.firstWhere((r) => r.id == chatId);
+      expect(room.lastMessage?.id, 200);
+      expect(room.unreadMessagesCount, 1);
+      expect(chatsCubit.state.chatsWithUnreadMessagesCount, 1);
+
+      await controller.close();
+    });
+
+    test('_handleNewMessageViaSocket - повторная доставка того же id не двоит непрочитанное', () async {
+      const chatId = 'chat-id';
+      chatsCubit.emit(ChatsState(state: BaseState.success, chatRooms: [buildChatRoom(chatId)]));
+      when(mockWsManager.userId).thenReturn(42);
+
+      final controller = await connectToSocketStream();
+      controller.add(socketEvent(id: 300, authorId: 7, roomId: chatId));
+      await Future.delayed(const Duration(milliseconds: 100));
+      controller.add(socketEvent(id: 300, authorId: 7, roomId: chatId));
+      await Future.delayed(const Duration(milliseconds: 100));
+
+      final room = chatsCubit.state.chatRooms.firstWhere((r) => r.id == chatId);
+      expect(room.unreadMessagesCount, 1);
+      expect(chatsCubit.state.chatsWithUnreadMessagesCount, 1);
+
+      await controller.close();
+    });
+
+    test('_handleNewMessageViaSocket - чужое сообщение в непрочитанном чате не поднимает счётчик чатов', () async {
+      const chatId = 'chat-id';
+      chatsCubit.emit(
+        ChatsState(state: BaseState.success, chatRooms: [buildChatRoom(chatId, unread: 2)], chatsWithUnreadMessagesCount: 1),
+      );
+      when(mockWsManager.userId).thenReturn(42);
+
+      final controller = await connectToSocketStream();
+      controller.add(socketEvent(id: 400, authorId: 7, roomId: chatId));
+      await Future.delayed(const Duration(milliseconds: 100));
+
+      final room = chatsCubit.state.chatRooms.firstWhere((r) => r.id == chatId);
+      expect(room.unreadMessagesCount, 3);
+      expect(chatsCubit.state.chatsWithUnreadMessagesCount, 1);
+
+      await controller.close();
+    });
+
     test('close - закрывает cubit и отписывается от подписок', () async {
       final mockSubscription1 = MockStreamSubscription();
 
@@ -476,3 +580,12 @@ void main() {
     });
   });
 }
+
+/// Облегчённый фейк события канала: ChatsCubit использует только event.data,
+/// поэтому реальный ChannelReadEvent (требует Channel) не нужен.
+class _FakeChannelReadEvent extends Fake implements ChannelReadEvent {
+  _FakeChannelReadEvent(this.data);
+
+  @override
+  final dynamic data;
+}