diff --git a/chats/serializers.py b/chats/serializers.py
index 9c6200b0..75d7df13 100644
--- a/chats/serializers.py
+++ b/chats/serializers.py
@@ -7,7 +7,7 @@
     ProjectChatMessage,
 )
 from files.serializers import UserFileSerializer
-from users.serializers import UserListSerializer, UserDetailSerializer
+from users.serializers import UserListSerializer, UserDetailSerializer, UserChatSerializer
 
 
 class DirectChatListSerializer(serializers.ModelSerializer):
@@ -128,7 +128,8 @@ class Meta:
 
 
 class DirectChatMessageListSerializer(serializers.ModelSerializer):
-    author = UserDetailSerializer()
+    # author = UserDetailSerializer()
+    author = UserChatSerializer()
     reply_to = DirectChatMessageSerializer(allow_null=True)
     files = serializers.SerializerMethodField()
 
diff --git a/users/serializers.py b/users/serializers.py
index c7caf56b..a255571c 100644
--- a/users/serializers.py
+++ b/users/serializers.py
@@ -349,6 +349,29 @@ def update(self, instance, validated_data):
         return instance
 
 
+class UserChatSerializer(serializers.ModelSerializer[CustomUser]):
+    is_online = serializers.SerializerMethodField()
+
+    def get_is_online(self, user: CustomUser):
+        request = self.context.get("request")
+        if request and request.user.is_authenticated and request.user.id == user.id:
+            return True
+        cache_key = get_user_online_cache_key(user)
+        return cache.get(cache_key, False)
+
+    class Meta:
+        model = CustomUser
+        fields = [
+            "id",
+            "first_name",
+            "last_name",
+            "patronymic",
+            "avatar",
+            "is_active",
+            "is_online",
+        ]
+
+
 class UserListSerializer(
     serializers.ModelSerializer[CustomUser], SkillsWriteSerializerMixin
 ):