--- Client/Assets/Scripts/Services/UserService.cs (reviewed baseline)

+++ Client/Assets/Scripts/Services/UserService.cs

@@ -155,6 +155,9 @@

             GContext.OnEvent<EvtAPISvrUnauthorized>().Subscribe(evt =>
             {
                 if (evt.SessionVersion != customServerMgr.SessionVersion) return;
+#if UNITY_EDITOR && !SERVICE_HOST
+                if(game.PlayerDataStorage.PlayerKVGameplayLoop.Enabled) { game.PlayerDataStorage.PlayerKVGameplayLoop.Fault("API unauthorized; restart required."); return; }
+#endif
                 InternalId = 0;
                 if (PlayFabClientAPI.IsClientLoggedIn()) _ = LoginApiServer();
             });
@@ -185,6 +188,9 @@

 
         private async Task<ELoginStep> LoginCore(Action<int> progress, int generation)
         {
+#if UNITY_EDITOR && !SERVICE_HOST
+            if(game.PlayerDataStorage.PlayerKVGameplayLoop.Enabled) return await LoginKVGameplayLoopAsync(progress,generation);
+#endif
             if (IsLogin)
             {
                 progress?.Invoke(2);
@@ -344,7 +350,11 @@

             var info_request_parameters = new GetPlayerCombinedInfoRequestParams
             {
                 GetUserAccountInfo = true,
+#if UNITY_EDITOR && !SERVICE_HOST
+                GetUserData = !game.PlayerDataStorage.PlayerKVGameplayLoop.Enabled,
+#else
                 GetUserData = true,
+#endif
                 GetPlayerProfile = true,
                 ProfileConstraints = new PlayerProfileViewConstraints()
                 {
@@ -507,6 +517,9 @@

 
             //InitData should invoke after local time adjusted.
             //save login time to local storage.
+#if UNITY_EDITOR && !SERVICE_HOST
+            if(!game.PlayerDataStorage.PlayerKVGameplayLoop.Enabled)
+#endif
             InitData(playfabUserData, UserId);
 
             return true;
@@ -546,6 +559,9 @@

                     return false;
                 }
                 customServerMgr.UseAccountSession(session);
+#if UNITY_EDITOR && !SERVICE_HOST
+                if(game.PlayerDataStorage.PlayerKVGameplayLoop.Enabled) return true; // Identity is published only after all KV modules load.
+#endif
                 InternalId = session.InternalId;
                 GContext.Publish(new EvtAPISvrLoginSuccess
                 {
@@ -655,6 +671,9 @@

 
         public virtual void Logout()
         {
+#if UNITY_EDITOR && !SERVICE_HOST
+            if(game.PlayerDataStorage.PlayerKVGameplayLoop.Enabled) { _=StopKVGameplayLoopAsync(); return; }
+#endif
             if(kvControlledInstance)
             {
                 logoutGeneration++; InternalId=0; UserId=null; DisplayName=null; AvatarUrl=null;