diff --git a/Sagaway.IntegrationTests/Sagaway.IntegrationTests.OrchestrationService/Actors/TestActor.cs b/Sagaway.IntegrationTests/Sagaway.IntegrationTests.OrchestrationService/Actors/TestActor.cs
index b84be5d..ec505b3 100644
--- a/Sagaway.IntegrationTests/Sagaway.IntegrationTests.OrchestrationService/Actors/TestActor.cs
+++ b/Sagaway.IntegrationTests/Sagaway.IntegrationTests.OrchestrationService/Actors/TestActor.cs
@@ -33,10 +33,16 @@ protected override ISaga<TestActorOperations> ReBuildSaga()
         }
 
         var sagaBuilder = Saga<TestActorOperations>.Create(_actorHost.Id.ToString(), this, _logger)
-            .WithOnSuccessCompletionCallback(OnSuccessCompletionCallbackAsync)
-            .WithOnRevertedCallback(OnRevertedCallbackAsync)
-            .WithOnFailedRevertedCallback(OnFailedRevertedCallbackAsync)
-            .WithOnFailedCallback(OnFailedCallbackAsync);
+                // Synchronous Callbacks
+                .WithOnSuccessCompletionCallback(OnSuccessCompletionCallback)
+                .WithOnRevertedCallback(OnRevertedCallback)
+                .WithOnFailedRevertedCallback(OnFailedRevertedCallback)
+                .WithOnFailedCallback(OnFailedCallback)
+                // Asynchronous Callbacks
+                .WithOnSuccessCompletionCallbackAsync(OnSuccessCompletionCallbackAsync)
+                .WithOnRevertedCallbackAsync(OnRevertedCallbackAsync)
+                .WithOnFailedRevertedCallbackAsync(OnFailedRevertedCallbackAsync)
+                .WithOnFailedCallbackAsync(OnFailedCallbackAsync);
 
         if (_testInfo?.ServiceACall?.InUse ?? false)
         {
@@ -311,58 +317,93 @@ private async Task<bool> ValidateRevertCallTestServiceAsync(TestActorOperations
 
     #region Saga Completion Methods
 
-    private async void OnFailedRevertedCallbackAsync(string sagaLog)
+    // Synchronous Callback Methods
+    private void OnSuccessCompletionCallback(string sagaLog)
     {
-        _logger.LogError("The Test {TestName} has resulted a failure and left some unused resources. log: {sagaLog}", _testInfo!.TestName,
-            Environment.NewLine + sagaLog);
+        _logger.LogError("The Test {TestName} has resulted in success. (Synchronous Callback) log: {sagaLog}", _testInfo!.TestName, sagaLog);
+        var testResult = new TestResult
+        {
+            TestInfo = _testInfo,
+            IsSuccess = true,
+            SagaLog = sagaLog
+        };
+        Task.Run(() => PublishMessageToSignalRAsync(testResult));
+    }
 
+    private void OnRevertedCallback(string sagaLog)
+    {
+        _logger.LogError("The Test {TestName} has resulted in a failure. All resources are deleted. (Synchronous Callback) log: {sagaLog}", _testInfo!.TestName, sagaLog);
         var testResult = new TestResult
         {
             TestInfo = _testInfo,
             IsSuccess = false,
             SagaLog = sagaLog
         };
-
-        await PublishMessageToSignalRAsync(testResult);
+        Task.Run(() => PublishMessageToSignalRAsync(testResult));
     }
 
-    private async void OnRevertedCallbackAsync(string sagaLog)
+    private void OnFailedRevertedCallback(string sagaLog)
     {
-        _logger.LogError("The Test {TestName} has resulted a failure. log: {sagaLog}", _testInfo!.TestName,
-            Environment.NewLine + sagaLog);
-
+        _logger.LogError("The Test {TestName} has failed and left some unused resources. (Synchronous Callback) log: {sagaLog}", _testInfo!.TestName, sagaLog);
         var testResult = new TestResult
         {
             TestInfo = _testInfo,
             IsSuccess = false,
             SagaLog = sagaLog
         };
-
-        await PublishMessageToSignalRAsync(testResult);
+        Task.Run(() => PublishMessageToSignalRAsync(testResult));
     }
 
-    private async void OnFailedCallbackAsync(string sagaLog)
+    private void OnFailedCallback(string sagaLog)
     {
-        _logger.LogError("The Test {TestName} has resulted a failure, starting reverting resources.", _testInfo!.TestName);
-
-        await Task.CompletedTask;
+        _logger.LogError("The Test {TestName} has failed. Starting to revert resources. (Synchronous Callback)", _testInfo!.TestName);
+        // Optionally, send a message to the customer
     }
 
-    private async void OnSuccessCompletionCallbackAsync(string sagaLog)
+    // Asynchronous Callback Methods
+    private async Task OnSuccessCompletionCallbackAsync(string sagaLog)
     {
-        _logger.LogError("The Test {TestName} has resulted a success. log: {sagaLog}", _testInfo!.TestName,
-            Environment.NewLine + sagaLog);
-
+        _logger.LogError("The Test {TestName} has resulted in success. (Asynchronous Callback) log: {sagaLog}", _testInfo!.TestName, sagaLog);
         var testResult = new TestResult
         {
             TestInfo = _testInfo,
             IsSuccess = true,
             SagaLog = sagaLog
         };
+        await PublishMessageToSignalRAsync(testResult);
+    }
 
+    private async Task OnRevertedCallbackAsync(string sagaLog)
+    {
+        _logger.LogError("The Test {TestName} has resulted in a failure. All resources are deleted. (Asynchronous Callback) log: {sagaLog}", _testInfo!.TestName, sagaLog);
+        var testResult = new TestResult
+        {
+            TestInfo = _testInfo,
+            IsSuccess = false,
+            SagaLog = sagaLog
+        };
         await PublishMessageToSignalRAsync(testResult);
     }
 
+    private async Task OnFailedRevertedCallbackAsync(string sagaLog)
+    {
+        _logger.LogError("The Test {TestName} has failed and left some unused resources. (Asynchronous Callback) log: {sagaLog}", _testInfo!.TestName, sagaLog);
+        var testResult = new TestResult
+        {
+            TestInfo = _testInfo,
+            IsSuccess = false,
+            SagaLog = sagaLog
+        };
+        await PublishMessageToSignalRAsync(testResult);
+    }
+
+    private async Task OnFailedCallbackAsync(string sagaLog)
+    {
+        _logger.LogError("The Test {TestName} has failed. Starting to revert resources. (Asynchronous Callback)", _testInfo!.TestName);
+        // Optionally, send a message to the customer
+        await Task.CompletedTask;
+    }
+
     private async Task OnSagaCompletedAsync(object? _, SagaCompletionEventArgs e)
     {
         _logger.LogInformation($"Saga {e.SagaId} completed with status {e.Status}");
diff --git a/Sagaway.IntegrationTests/Sagaway.IntegrationTests.TestSubSagaCommunicationService/MainSagaActor.cs b/Sagaway.IntegrationTests/Sagaway.IntegrationTests.TestSubSagaCommunicationService/MainSagaActor.cs
index 19e65c2..f7dcd1a 100644
--- a/Sagaway.IntegrationTests/Sagaway.IntegrationTests.TestSubSagaCommunicationService/MainSagaActor.cs
+++ b/Sagaway.IntegrationTests/Sagaway.IntegrationTests.TestSubSagaCommunicationService/MainSagaActor.cs
@@ -17,10 +17,17 @@ public MainSagaActor(ActorHost host, ILogger<MainSagaActor> logger, IServiceProv
     protected override ISaga<MainSagaActorOperations> ReBuildSaga()
     {
         var sagaBuilder = Saga<MainSagaActorOperations>.Create(ActorHost.Id.ToString(), this, Logger)
-            .WithOnSuccessCompletionCallback(OnSuccessCompletionCallbackAsync)
-            .WithOnRevertedCallback(OnRevertedCallbackAsync)
-            .WithOnFailedRevertedCallback(OnFailedRevertedCallbackAsync)
-            .WithOnFailedCallback(OnFailedCallbackAsync)
+            // Synchronous Callbacks
+            .WithOnSuccessCompletionCallback(OnSuccessCompletionCallback)
+            .WithOnRevertedCallback(OnRevertedCallback)
+            .WithOnFailedRevertedCallback(OnFailedRevertedCallback)
+            .WithOnFailedCallback(OnFailedCallback)
+
+            // Asynchronous Callbacks
+            .WithOnSuccessCompletionCallbackAsync(OnSuccessCompletionCallbackAsync)
+            .WithOnRevertedCallbackAsync(OnRevertedCallbackAsync)
+            .WithOnFailedRevertedCallbackAsync(OnFailedRevertedCallbackAsync)
+            .WithOnFailedCallbackAsync(OnFailedCallbackAsync)
 
             .WithOperation(MainSagaActorOperations.CallSubSaga)
             .WithDoOperation(OnCallSubSagaAsync)
@@ -67,27 +74,52 @@ public Task<TestResult> GetTestResultAsync()
         return Task.FromResult(_testResult);
     }
 
+    // Synchronous Callback Methods
+    private void OnSuccessCompletionCallback(string log)
+    {
+        Logger.LogInformation("MainSagaActor completed successfully. (Synchronous Callback)");
+    }
+
+    private void OnRevertedCallback(string log)
+    {
+        Logger.LogInformation("MainSagaActor reverted successfully. (Synchronous Callback)");
+    }
+
+    private void OnFailedRevertedCallback(string log)
+    {
+        Logger.LogInformation("MainSagaActor failed to revert. (Synchronous Callback)");
+    }
+
+    private void OnFailedCallback(string log)
+    {
+        Logger.LogInformation("MainSagaActor failed. (Synchronous Callback)");
+    }
 
-    private void OnSuccessCompletionCallbackAsync(string obj)
+    // Asynchronous Callback Methods
+    private async Task OnSuccessCompletionCallbackAsync(string log)
     {
         _testResult = TestResult.Succeeded;
-        Logger.LogInformation("MainSagaActor completed successfully.");
+        Logger.LogInformation("MainSagaActor completed successfully. (Asynchronous Callback)");
+        await Task.CompletedTask;
     }
 
-    private void OnRevertedCallbackAsync(string obj)
+    private async Task OnRevertedCallbackAsync(string log)
     {
-        Logger.LogInformation("MainSagaActor reverted successfully.");
+        Logger.LogInformation("MainSagaActor reverted successfully. (Asynchronous Callback)");
+        await Task.CompletedTask;
     }
 
-    private void OnFailedRevertedCallbackAsync(string obj)
+    private async Task OnFailedRevertedCallbackAsync(string log)
     {
-        Logger.LogInformation("MainSagaActor failed to revert.");
+        Logger.LogInformation("MainSagaActor failed to revert. (Asynchronous Callback)");
+        await Task.CompletedTask;
     }
 
-    private void OnFailedCallbackAsync(string obj)
+    private async Task OnFailedCallbackAsync(string log)
     {
         _testResult = TestResult.Failed;
-        Logger.LogInformation("MainSagaActor failed.");
+        Logger.LogInformation("MainSagaActor failed. (Asynchronous Callback)");
+        await Task.CompletedTask;
     }
 
     private async Task OnCallSubSagaAsync()
diff --git a/Sagaway.IntegrationTests/Sagaway.IntegrationTests.TestSubSagaCommunicationService/SubSagaActor.cs b/Sagaway.IntegrationTests/Sagaway.IntegrationTests.TestSubSagaCommunicationService/SubSagaActor.cs
index 7c08ae2..59a2ea8 100644
--- a/Sagaway.IntegrationTests/Sagaway.IntegrationTests.TestSubSagaCommunicationService/SubSagaActor.cs
+++ b/Sagaway.IntegrationTests/Sagaway.IntegrationTests.TestSubSagaCommunicationService/SubSagaActor.cs
@@ -17,10 +17,16 @@ public SubSagaActor(ActorHost host, ILogger<SubSagaActor> logger, IServiceProvid
     protected override ISaga<SubSagaActorOperations> ReBuildSaga()
     {
         var sagaBuilder = Saga<SubSagaActorOperations>.Create(ActorHost.Id.ToString(), this, Logger)
-            .WithOnSuccessCompletionCallback(OnSuccessCompletionCallbackAsync)
-            .WithOnRevertedCallback(OnRevertedCallbackAsync)
-            .WithOnFailedRevertedCallback(OnFailedRevertedCallbackAsync)
-            .WithOnFailedCallback(OnFailedCallbackAsync)
+             // Synchronous Callbacks
+            .WithOnSuccessCompletionCallback(OnSuccessCompletionCallback)
+            .WithOnRevertedCallback(OnRevertedCallback)
+            .WithOnFailedRevertedCallback(OnFailedRevertedCallback)
+            .WithOnFailedCallback(OnFailedCallback)
+            // Asynchronous Callbacks
+            .WithOnSuccessCompletionCallbackAsync(OnSuccessCompletionCallbackAsync)
+            .WithOnRevertedCallbackAsync(OnRevertedCallbackAsync)
+            .WithOnFailedRevertedCallbackAsync(OnFailedRevertedCallbackAsync)
+            .WithOnFailedCallbackAsync(OnFailedCallbackAsync)
 
             .WithOperation(SubSagaActorOperations.Add)
             .WithDoOperation(OnAddInSubSagaAsync)
@@ -68,7 +74,7 @@ public async Task AddAsync(int a, int b, TimeSpan delay)
     private async Task OnAddInSubSagaAsync()
     {
         //take delay from state store
-        var delay = StateManager.GetStateAsync<double>("delay").Result;
+        var delay = await StateManager.GetStateAsync<double>("delay");
         Logger.LogInformation("AddInSubSagaAsync called to test the sub-saga with delay {Delay}", delay);
 
         await Task.Delay(TimeSpan.FromSeconds(delay));
@@ -93,24 +99,50 @@ public async Task DoneAsync()
         await CallbackMainSagaAsync(new DoneResult {Result = true});
     }
 
-    private void OnSuccessCompletionCallbackAsync(string obj)
+    // Synchronous Callback Methods
+    private void OnSuccessCompletionCallback(string log)
     {
-        Logger.LogInformation("MainSagaActor completed successfully.");
+        Logger.LogInformation("SubSagaActor completed successfully. (Synchronous Callback)");
     }
 
-    private void OnRevertedCallbackAsync(string obj)
+    private void OnRevertedCallback(string log)
     {
-        Logger.LogInformation("MainSagaActor reverted successfully.");
+        Logger.LogInformation("SubSagaActor reverted successfully. (Synchronous Callback)");
     }
 
-    private void OnFailedRevertedCallbackAsync(string obj)
+    private void OnFailedRevertedCallback(string log)
     {
-        Logger.LogInformation("MainSagaActor failed to revert.");
+        Logger.LogInformation("SubSagaActor failed to revert. (Synchronous Callback)");
     }
 
-    private void OnFailedCallbackAsync(string obj)
+    private void OnFailedCallback(string log)
     {
-        Logger.LogInformation("MainSagaActor failed.");
+        Logger.LogInformation("SubSagaActor failed. (Synchronous Callback)");
+    }
+
+    // Asynchronous Callback Methods
+    private async Task OnSuccessCompletionCallbackAsync(string log)
+    {
+        Logger.LogInformation("SubSagaActor completed successfully. (Asynchronous Callback)");
+        await Task.CompletedTask;
+    }
+
+    private async Task OnRevertedCallbackAsync(string log)
+    {
+        Logger.LogInformation("SubSagaActor reverted successfully. (Asynchronous Callback)");
+        await Task.CompletedTask;
+    }
+
+    private async Task OnFailedRevertedCallbackAsync(string log)
+    {
+        Logger.LogInformation("SubSagaActor failed to revert. (Asynchronous Callback)");
+        await Task.CompletedTask;
+    }
+
+    private async Task OnFailedCallbackAsync(string log)
+    {
+        Logger.LogInformation("SubSagaActor failed. (Asynchronous Callback)");
+        await Task.CompletedTask;
     }
 
     private Task OnEndSagaAsync()
diff --git a/Sagaway.ReservationDemo/Sagaway.ReservationDemo.ReservationManager/Actors/CarReservation/CarReservationActor.cs b/Sagaway.ReservationDemo/Sagaway.ReservationDemo.ReservationManager/Actors/CarReservation/CarReservationActor.cs
index 8fa8c9c..6e83817 100644
--- a/Sagaway.ReservationDemo/Sagaway.ReservationDemo.ReservationManager/Actors/CarReservation/CarReservationActor.cs
+++ b/Sagaway.ReservationDemo/Sagaway.ReservationDemo.ReservationManager/Actors/CarReservation/CarReservationActor.cs
@@ -26,10 +26,16 @@ public CarReservationActor(ActorHost host, ILogger<CarReservationActor> logger,
     protected override ISaga<CarReservationActorOperations> ReBuildSaga()
     {
         var saga = Saga<CarReservationActorOperations>.Create(_actorHost.Id.ToString(), this, _logger)
-            .WithOnSuccessCompletionCallback(OnSuccessCompletionCallbackAsync)
-            .WithOnRevertedCallback(OnRevertedCallbackAsync)
-            .WithOnFailedRevertedCallback(OnFailedRevertedCallbackAsync)
-            .WithOnFailedCallback(OnFailedCallbackAsync)
+            // Synchronous Callbacks
+            .WithOnSuccessCompletionCallback(OnSuccessCompletionCallback)
+            .WithOnRevertedCallback(OnRevertedCallback)
+            .WithOnFailedRevertedCallback(OnFailedRevertedCallback)
+            .WithOnFailedCallback(OnFailedCallback)
+            // Asynchronous Callbacks
+            .WithOnSuccessCompletionCallbackAsync(OnSuccessCompletionCallbackAsync)
+            .WithOnRevertedCallbackAsync(OnRevertedCallbackAsync)
+            .WithOnFailedRevertedCallbackAsync(OnFailedRevertedCallbackAsync)
+            .WithOnFailedCallbackAsync(OnFailedCallbackAsync)
 
             .WithOperation(CarReservationActorOperations.CarBooking)
             .WithDoOperation(BookCarReservationAsync)
@@ -336,38 +342,62 @@ private async Task<bool> ValidateRevertBillReservationAsync()
 
     #region Saga Completion Methods
 
-    private async void OnFailedRevertedCallbackAsync(string sagaLog)
+    // Synchronous Callback Methods
+    private void OnSuccessCompletionCallback(string sagaLog)
     {
-        _logger.LogError("The car reservation has failed and left some unused resources.");
+        _logger.LogInformation("The car reservation has succeeded. (Synchronous Callback)");
+        _logger.LogInformation("The car reservation log:" + Environment.NewLine + sagaLog);
+        // Optionally, send a message to the customer
+    }
+
+    private void OnRevertedCallback(string sagaLog)
+    {
+        _logger.LogError("The car reservation has failed and all resources are deleted. (Synchronous Callback)");
         _logger.LogError("The car reservation log:" + Environment.NewLine + sagaLog);
+    }
 
-        await Task.CompletedTask;
+    private void OnFailedRevertedCallback(string sagaLog)
+    {
+        _logger.LogError("The car reservation has failed and left some unused resources. (Synchronous Callback)");
+        _logger.LogError("The car reservation log:" + Environment.NewLine + sagaLog);
     }
 
-    private async void OnRevertedCallbackAsync(string sagaLog)
+    private void OnFailedCallback(string sagaLog)
     {
-        _logger.LogError("The car reservation has failed and all resources are deleted.");
+        _logger.LogError("The car reservation has failed starting reverting resources. (Synchronous Callback)");
         _logger.LogError("The car reservation log:" + Environment.NewLine + sagaLog);
+        // Optionally, send a message to the customer
+    }
 
+    // Asynchronous Callback Methods
+    private async Task OnSuccessCompletionCallbackAsync(string sagaLog)
+    {
+        _logger.LogInformation("The car reservation has succeeded. (Asynchronous Callback)");
+        _logger.LogInformation("The car reservation log:" + Environment.NewLine + sagaLog);
+        // Optionally, send a message to the customer
         await Task.CompletedTask;
     }
 
-    private async void OnFailedCallbackAsync(string sagaLog)
+    private async Task OnRevertedCallbackAsync(string sagaLog)
     {
-        _logger.LogError("The car reservation has failed starting reverting resources.");
+        _logger.LogError("The car reservation has failed and all resources are deleted. (Asynchronous Callback)");
         _logger.LogError("The car reservation log:" + Environment.NewLine + sagaLog);
-
         await Task.CompletedTask;
-        //Option: Send a message to the customer
     }
 
-    private async void OnSuccessCompletionCallbackAsync(string sagaLog)
+    private async Task OnFailedRevertedCallbackAsync(string sagaLog)
     {
-        _logger.LogInformation("The car reservation has succeeded.");
-        _logger.LogInformation("The car reservation log:" + Environment.NewLine + sagaLog);
+        _logger.LogError("The car reservation has failed and left some unused resources. (Asynchronous Callback)");
+        _logger.LogError("The car reservation log:" + Environment.NewLine + sagaLog);
+        await Task.CompletedTask;
+    }
 
+    private async Task OnFailedCallbackAsync(string sagaLog)
+    {
+        _logger.LogError("The car reservation has failed starting reverting resources. (Asynchronous Callback)");
+        _logger.LogError("The car reservation log:" + Environment.NewLine + sagaLog);
+        // Optionally, send a message to the customer
         await Task.CompletedTask;
-        //Option: Send a message to the customer
     }
 
     private async Task OnSagaCompletedAsync(object? _, SagaCompletionEventArgs e)
diff --git a/Sagaway.ReservationDemo/Sagaway.ReservationDemo.ReservationManager/Actors/CarReservationCancellation/CarReservationCancellationActor.cs b/Sagaway.ReservationDemo/Sagaway.ReservationDemo.ReservationManager/Actors/CarReservationCancellation/CarReservationCancellationActor.cs
index 5afe7a7..f93e508 100644
--- a/Sagaway.ReservationDemo/Sagaway.ReservationDemo.ReservationManager/Actors/CarReservationCancellation/CarReservationCancellationActor.cs
+++ b/Sagaway.ReservationDemo/Sagaway.ReservationDemo.ReservationManager/Actors/CarReservationCancellation/CarReservationCancellationActor.cs
@@ -27,10 +27,16 @@ public CarReservationCancellationActor(ActorHost host, ILogger<CarReservationCan
     protected override ISaga<CarCancelReservationActorOperations> ReBuildSaga()
     {
         var saga = Saga<CarCancelReservationActorOperations>.Create(_actorHost.Id.ToString(), this, _logger)
-            .WithOnSuccessCompletionCallback(OnSuccessCompletionCallbackAsync)
-            .WithOnRevertedCallback(OnRevertedCallbackAsync)
-            .WithOnFailedRevertedCallback(OnFailedRevertedCallbackAsync)
-            .WithOnFailedCallback(OnFailedCallbackAsync)
+            // Synchronous Callbacks
+            .WithOnSuccessCompletionCallback(OnSuccessCompletionCallback)
+            .WithOnRevertedCallback(OnRevertedCallback)
+            .WithOnFailedRevertedCallback(OnFailedRevertedCallback)
+            .WithOnFailedCallback(OnFailedCallback)
+            // Asynchronous Callbacks
+            .WithOnSuccessCompletionCallbackAsync(OnSuccessCompletionCallbackAsync)
+            .WithOnRevertedCallbackAsync(OnRevertedCallbackAsync)
+            .WithOnFailedRevertedCallbackAsync(OnFailedRevertedCallbackAsync)
+            .WithOnFailedCallbackAsync(OnFailedCallbackAsync)
 
             .WithOperation(CarCancelReservationActorOperations.CancelBooking)
             .WithDoOperation(CancelCarBookingAsync)
@@ -356,38 +362,62 @@ await DaprClient.InvokeMethodAsync<BillingState>(HttpMethod.Get, "billing-manage
 
     #region Saga Completion Methods
 
-    private async void OnFailedRevertedCallbackAsync(string sagaLog)
+    // Synchronous Callback Methods
+    private void OnSuccessCompletionCallback(string sagaLog)
     {
-        _logger.LogError("The car reservation cancelling has failed and left some unused resources.");
+        _logger.LogInformation("The car reservation cancelling has succeeded. (Synchronous Callback)");
+        _logger.LogInformation("The car reservation cancelling log:" + Environment.NewLine + sagaLog);
+        // Optionally, send a message to the customer
+    }
+
+    private void OnRevertedCallback(string sagaLog)
+    {
+        _logger.LogError("The car reservation cancelling has failed and all resources are deleted. (Synchronous Callback)");
         _logger.LogError("The car reservation cancelling log:" + Environment.NewLine + sagaLog);
+    }
 
-        await Task.CompletedTask;
+    private void OnFailedRevertedCallback(string sagaLog)
+    {
+        _logger.LogError("The car reservation cancelling has failed and left some unused resources. (Synchronous Callback)");
+        _logger.LogError("The car reservation cancelling log:" + Environment.NewLine + sagaLog);
     }
 
-    private async void OnRevertedCallbackAsync(string sagaLog)
+    private void OnFailedCallback(string sagaLog)
     {
-        _logger.LogError("The car reservation cancelling has failed and all resources are deleted.");
+        _logger.LogError("The car reservation cancelling has failed starting reverting resources. (Synchronous Callback)");
         _logger.LogError("The car reservation cancelling log:" + Environment.NewLine + sagaLog);
+        // Optionally, send a message to the customer
+    }
 
-        await Task.CompletedTask;
+    // Asynchronous Callback Methods
+    private Task OnSuccessCompletionCallbackAsync(string sagaLog)
+    {
+        _logger.LogInformation("The car reservation cancelling has succeeded. (Asynchronous Callback)");
+        _logger.LogInformation("The car reservation cancelling log:" + Environment.NewLine + sagaLog);
+        // Optionally, send a message to the customer
+        return Task.CompletedTask;
     }
 
-    private async void OnFailedCallbackAsync(string sagaLog)
+    private Task OnRevertedCallbackAsync(string sagaLog)
     {
-        _logger.LogError("The car reservation cancelling has failed starting reverting resources.");
+        _logger.LogError("The car reservation cancelling has failed and all resources are deleted. (Asynchronous Callback)");
         _logger.LogError("The car reservation cancelling log:" + Environment.NewLine + sagaLog);
-
-        await Task.CompletedTask;
-        //Option: Send a message to the customer
+        return Task.CompletedTask;
     }
 
-    private async void OnSuccessCompletionCallbackAsync(string sagaLog)
+    private Task OnFailedRevertedCallbackAsync(string sagaLog)
     {
-        _logger.LogInformation("The car reservation cancelling has succeeded.");
-        _logger.LogInformation("The car reservation cancelling log:" + Environment.NewLine + sagaLog);
+        _logger.LogError("The car reservation cancelling has failed and left some unused resources. (Asynchronous Callback)");
+        _logger.LogError("The car reservation cancelling log:" + Environment.NewLine + sagaLog);
+        return Task.CompletedTask;
+    }
 
-        await Task.CompletedTask;
-        //Option: Send a message to the customer
+    private Task OnFailedCallbackAsync(string sagaLog)
+    {
+        _logger.LogError("The car reservation cancelling has failed starting reverting resources. (Asynchronous Callback)");
+        _logger.LogError("The car reservation cancelling log:" + Environment.NewLine + sagaLog);
+        // Optionally, send a message to the customer
+        return Task.CompletedTask;
     }
 
     private async Task OnSagaCompletedAsync(object? _, SagaCompletionEventArgs e)
diff --git a/Sagaway.Tests/ApprovalFiles/test_O1_After_O2_and_O3.approved.txt b/Sagaway.Tests/ApprovalFiles/test_O1_After_O2_and_O3.approved.txt
index 72632bb..9b4265f 100644
--- a/Sagaway.Tests/ApprovalFiles/test_O1_After_O2_and_O3.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_O1_After_O2_and_O3.approved.txt
@@ -80,7 +80,7 @@ HasRevertValidate: False
 Calling Op2: Success True
 Calling Op3: Success True
 Calling Op1: Success True
-OnSuccessCompletionCallback: Success.
+OnSuccessCompletionCallbackAsync: Success.
 Run Log:
 [*time*][Op2]: Start Executing Op2
 [*time*][Op2]: Op2 Success
diff --git a/Sagaway.Tests/ApprovalFiles/test_O1_O2_O3_O5_O4.approved.txt b/Sagaway.Tests/ApprovalFiles/test_O1_O2_O3_O5_O4.approved.txt
index a3c7c55..829d7e3 100644
--- a/Sagaway.Tests/ApprovalFiles/test_O1_O2_O3_O5_O4.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_O1_O2_O3_O5_O4.approved.txt
@@ -134,7 +134,7 @@ Calling Op2: Success True
 Calling Op3: Success True
 Calling Op5: Success True
 Calling Op4: Success True
-OnSuccessCompletionCallback: Success.
+OnSuccessCompletionCallbackAsync: Success.
 Run Log:
 [*time*][Op1]: Start Executing Op1
 [*time*][Op1]: Op1 Success
diff --git a/Sagaway.Tests/ApprovalFiles/test_O5_O4_O3_O2_O1.approved.txt b/Sagaway.Tests/ApprovalFiles/test_O5_O4_O3_O2_O1.approved.txt
index 7359635..f8ddfd8 100644
--- a/Sagaway.Tests/ApprovalFiles/test_O5_O4_O3_O2_O1.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_O5_O4_O3_O2_O1.approved.txt
@@ -134,7 +134,7 @@ Calling Op4: Success True
 Calling Op3: Success True
 Calling Op2: Success True
 Calling Op1: Success True
-OnSuccessCompletionCallback: Success.
+OnSuccessCompletionCallbackAsync: Success.
 Run Log:
 [*time*][Op5]: Start Executing Op5
 [*time*][Op5]: Op5 Success
diff --git a/Sagaway.Tests/ApprovalFiles/test_five_deactivated_each.approved.txt b/Sagaway.Tests/ApprovalFiles/test_five_deactivated_each.approved.txt
index 71b95e4..27561f0 100644
--- a/Sagaway.Tests/ApprovalFiles/test_five_deactivated_each.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_five_deactivated_each.approved.txt
@@ -139,7 +139,7 @@ Calling Op4: Success True
 Op4 Validate returns True
 Calling Op5: Success True
 Op5 Validate returns True
-OnSuccessCompletionCallback: Success.
+OnSuccessCompletionCallbackAsync: Success.
 Run Log:
 [*time*][Op1]: Start Executing Op1
 [*time*][Op1]: Registering reminder Op1:Retry for Op1 with interval 00:00:01
diff --git a/Sagaway.Tests/ApprovalFiles/test_five_deactivated_each_exponential_wait.approved.txt b/Sagaway.Tests/ApprovalFiles/test_five_deactivated_each_exponential_wait.approved.txt
index 2cc1e74..b46f25a 100644
--- a/Sagaway.Tests/ApprovalFiles/test_five_deactivated_each_exponential_wait.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_five_deactivated_each_exponential_wait.approved.txt
@@ -139,7 +139,7 @@ Calling Op4: Success True
 Op4 Validate returns True
 Calling Op5: Success True
 Op5 Validate returns True
-OnSuccessCompletionCallback: Success.
+OnSuccessCompletionCallbackAsync: Success.
 Run Log:
 [*time*][Op1]: Start Executing Op1
 [*time*][Op1]: Registering reminder Op1:Retry for Op1 with interval 00:00:02
diff --git a/Sagaway.Tests/ApprovalFiles/test_five_failfast_on_third.approved.txt b/Sagaway.Tests/ApprovalFiles/test_five_failfast_on_third.approved.txt
index 1acdfb6..a47c1da 100644
--- a/Sagaway.Tests/ApprovalFiles/test_five_failfast_on_third.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_five_failfast_on_third.approved.txt
@@ -133,7 +133,7 @@ HasRevertValidate: False
 Calling Op1: Success True
 Calling Op2: Success True
 Calling Op3: Success True
-OnRevertedCallback: Reverted.
+OnRevertedCallbackAsync: Reverted.
 Run Log:
 [*time*][Op1]: Start Executing Op1
 [*time*][Op1]: Op1 Success
@@ -161,4 +161,5 @@ OnSagaCompleted: Id: test Status: Reverted
 5: EndOperation - SagaID: test, Operation: Op2, Outcome: Succeeded
 6: StartOperation - SagaID: test, Operation: Op3
 7: EndOperation - SagaID: test, Operation: Op3, Outcome: Failed
-8: EndSaga - SagaID: test, Outcome: Reverted
+8: CustomEvent - SagaID: test, Event: SagaFailure, Properties: None
+9: EndSaga - SagaID: test, Outcome: Reverted
diff --git a/Sagaway.Tests/ApprovalFiles/test_five_fast_success_on_third.approved.txt b/Sagaway.Tests/ApprovalFiles/test_five_fast_success_on_third.approved.txt
index 2aa30dd..2fe99d5 100644
--- a/Sagaway.Tests/ApprovalFiles/test_five_fast_success_on_third.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_five_fast_success_on_third.approved.txt
@@ -133,7 +133,7 @@ HasRevertValidate: False
 Calling Op1: Success True
 Calling Op2: Success True
 Calling Op3: Success True
-OnSuccessCompletionCallback: Success.
+OnSuccessCompletionCallbackAsync: Success.
 Run Log:
 [*time*][Op1]: Start Executing Op1
 [*time*][Op1]: Op1 Success
diff --git a/Sagaway.Tests/ApprovalFiles/test_five_fast_success_on_third_with_second_done.approved.txt b/Sagaway.Tests/ApprovalFiles/test_five_fast_success_on_third_with_second_done.approved.txt
index f8b50e4..aa29b19 100644
--- a/Sagaway.Tests/ApprovalFiles/test_five_fast_success_on_third_with_second_done.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_five_fast_success_on_third_with_second_done.approved.txt
@@ -133,7 +133,7 @@ HasRevertValidate: False
 Calling Op1: Success True
 Calling Op2: Success True
 Calling Op3: Success True
-OnSuccessCompletionCallback: Success.
+OnSuccessCompletionCallbackAsync: Success.
 Run Log:
 [*time*][Op1]: Start Executing Op1
 [*time*][Op1]: Op1 Success
diff --git a/Sagaway.Tests/ApprovalFiles/test_five_success.approved.txt b/Sagaway.Tests/ApprovalFiles/test_five_success.approved.txt
index 9d1e6bf..1cafcf9 100644
--- a/Sagaway.Tests/ApprovalFiles/test_five_success.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_five_success.approved.txt
@@ -134,7 +134,7 @@ Calling Op2: Success True
 Calling Op3: Success True
 Calling Op4: Success True
 Calling Op5: Success True
-OnSuccessCompletionCallback: Success.
+OnSuccessCompletionCallbackAsync: Success.
 Run Log:
 [*time*][Op1]: Start Executing Op1
 [*time*][Op1]: Op1 Success
diff --git a/Sagaway.Tests/ApprovalFiles/test_five_throw_on_fifth.approved.txt b/Sagaway.Tests/ApprovalFiles/test_five_throw_on_fifth.approved.txt
index e9c8cbf..7547fd5 100644
--- a/Sagaway.Tests/ApprovalFiles/test_five_throw_on_fifth.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_five_throw_on_fifth.approved.txt
@@ -133,7 +133,7 @@ Calling Op1: Success True
 Calling Op2: Success True
 Calling Op3: Success True
 Calling Op4: Success True
-OnRevertedCallback: Reverted.
+OnRevertedCallbackAsync: Reverted.
 Run Log:
 [*time*][Op1]: Start Executing Op1
 [*time*][Op1]: Op1 Success
@@ -174,4 +174,5 @@ OnSagaCompleted: Id: test Status: Reverted
 10: StartOperation - SagaID: test, Operation: Op5
 11: Exception - SagaID: test, Context: Error when calling Op5, Exception: Throwing exception on call 1
 12: EndOperation - SagaID: test, Operation: Op5, Outcome: Failed
-13: EndSaga - SagaID: test, Outcome: Reverted
+13: CustomEvent - SagaID: test, Event: SagaFailure, Properties: None
+14: EndSaga - SagaID: test, Outcome: Reverted
diff --git a/Sagaway.Tests/ApprovalFiles/test_five_throw_on_fifth_report_failure.approved.txt b/Sagaway.Tests/ApprovalFiles/test_five_throw_on_fifth_report_failure.approved.txt
index 38ad54f..7b0d599 100644
--- a/Sagaway.Tests/ApprovalFiles/test_five_throw_on_fifth_report_failure.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_five_throw_on_fifth_report_failure.approved.txt
@@ -133,7 +133,7 @@ Calling Op1: Success True
 Calling Op2: Success True
 Calling Op3: Success True
 Calling Op4: Success True
-OnFailCallback: Fail.
+OnFailedCallbackAsync: Fail.
 Run Log:
 [*time*][Op1]: Start Executing Op1
 [*time*][Op1]: Op1 Success
diff --git a/Sagaway.Tests/ApprovalFiles/test_single_fail_and_exponential_retry.approved.txt b/Sagaway.Tests/ApprovalFiles/test_single_fail_and_exponential_retry.approved.txt
index c3d6284..624f743 100644
--- a/Sagaway.Tests/ApprovalFiles/test_single_fail_and_exponential_retry.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_single_fail_and_exponential_retry.approved.txt
@@ -27,7 +27,7 @@ HasRevertValidate: False
 
 Calling Op1: Success False
 Calling Op1: Success True
-OnSuccessCompletionCallback: Success.
+OnSuccessCompletionCallbackAsync: Success.
 Run Log:
 [*time*][Op1]: Start Executing Op1
 [*time*][Op1]: Registering reminder Op1:Retry for Op1 with interval 00:00:02
diff --git a/Sagaway.Tests/ApprovalFiles/test_single_fail_and_retry.approved.txt b/Sagaway.Tests/ApprovalFiles/test_single_fail_and_retry.approved.txt
index a1ca4f1..144b445 100644
--- a/Sagaway.Tests/ApprovalFiles/test_single_fail_and_retry.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_single_fail_and_retry.approved.txt
@@ -27,7 +27,7 @@ HasRevertValidate: False
 
 Calling Op1: Success False
 Calling Op1: Success True
-OnSuccessCompletionCallback: Success.
+OnSuccessCompletionCallbackAsync: Success.
 Run Log:
 [*time*][Op1]: Start Executing Op1
 [*time*][Op1]: Registering reminder Op1:Retry for Op1 with interval 00:00:10
diff --git a/Sagaway.Tests/ApprovalFiles/test_single_fail_fast_and_retry.approved.txt b/Sagaway.Tests/ApprovalFiles/test_single_fail_fast_and_retry.approved.txt
index cfe7abf..e32f59b 100644
--- a/Sagaway.Tests/ApprovalFiles/test_single_fail_fast_and_retry.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_single_fail_fast_and_retry.approved.txt
@@ -27,7 +27,7 @@ HasRevertValidate: False
 Set to fail fast
 
 Calling Op1: Success True
-OnRevertedCallback: Reverted.
+OnRevertedCallbackAsync: Reverted.
 Run Log:
 [*time*][Op1]: Start Executing Op1
 [*time*][Op1]: Registering reminder Op1:Retry for Op1 with interval 00:00:10
@@ -42,4 +42,5 @@ OnSagaCompleted: Id: test Status: Reverted
 1: StartSaga - SagaID: test, Type: SagaOperations
 2: StartOperation - SagaID: test, Operation: Op1
 3: EndOperation - SagaID: test, Operation: Op1, Outcome: Failed
-4: EndSaga - SagaID: test, Outcome: Reverted
+4: CustomEvent - SagaID: test, Event: SagaFailure, Properties: None
+5: EndSaga - SagaID: test, Outcome: Reverted
diff --git a/Sagaway.Tests/ApprovalFiles/test_single_fail_no_retry.approved.txt b/Sagaway.Tests/ApprovalFiles/test_single_fail_no_retry.approved.txt
index 1c35a20..d2e587d 100644
--- a/Sagaway.Tests/ApprovalFiles/test_single_fail_no_retry.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_single_fail_no_retry.approved.txt
@@ -26,7 +26,7 @@ HasValidate: False
 HasRevertValidate: False
 
 Calling Op1: Success False
-OnRevertedCallback: Reverted.
+OnRevertedCallbackAsync: Reverted.
 Run Log:
 [*time*][Op1]: Start Executing Op1
 [*time*][Op1]: Op1 Failed. Retries exhausted.
@@ -40,4 +40,5 @@ OnSagaCompleted: Id: test Status: Reverted
 1: StartSaga - SagaID: test, Type: SagaOperations
 2: StartOperation - SagaID: test, Operation: Op1
 3: EndOperation - SagaID: test, Operation: Op1, Outcome: Failed
-4: EndSaga - SagaID: test, Outcome: Reverted
+4: CustomEvent - SagaID: test, Event: SagaFailure, Properties: None
+5: EndSaga - SagaID: test, Outcome: Reverted
diff --git a/Sagaway.Tests/ApprovalFiles/test_single_fail_no_retry_report_failure.approved.txt b/Sagaway.Tests/ApprovalFiles/test_single_fail_no_retry_report_failure.approved.txt
index 70e37e1..b80113f 100644
--- a/Sagaway.Tests/ApprovalFiles/test_single_fail_no_retry_report_failure.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_single_fail_no_retry_report_failure.approved.txt
@@ -26,7 +26,7 @@ HasValidate: False
 HasRevertValidate: False
 
 Calling Op1: Success False
-OnFailCallback: Fail.
+OnFailedCallbackAsync: Fail.
 Run Log:
 [*time*][Op1]: Start Executing Op1
 [*time*][Op1]: Op1 Failed. Retries exhausted.
diff --git a/Sagaway.Tests/ApprovalFiles/test_single_long_wait_validate_exception.approved.txt b/Sagaway.Tests/ApprovalFiles/test_single_long_wait_validate_exception.approved.txt
index 8cac1b2..7cf9b9c 100644
--- a/Sagaway.Tests/ApprovalFiles/test_single_long_wait_validate_exception.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_single_long_wait_validate_exception.approved.txt
@@ -29,7 +29,7 @@ HasRevertValidate: False
 Calling Op1: Success True
 Calling Op1: Success True
 Op1 Validate returns True
-OnSuccessCompletionCallback: Success.
+OnSuccessCompletionCallbackAsync: Success.
 Run Log:
 [*time*][Op1]: Start Executing Op1
 [*time*][Op1]: Registering reminder Op1:Retry for Op1 with interval 00:00:02
diff --git a/Sagaway.Tests/ApprovalFiles/test_single_long_wait_validate_false.approved.txt b/Sagaway.Tests/ApprovalFiles/test_single_long_wait_validate_false.approved.txt
index cbceb5f..6ce35c8 100644
--- a/Sagaway.Tests/ApprovalFiles/test_single_long_wait_validate_false.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_single_long_wait_validate_false.approved.txt
@@ -29,7 +29,7 @@ Calling Op1: Success True
 Op1 Validate returns False
 Calling Op1: Success True
 Op1 Validate returns False
-OnRevertedCallback: Reverted.
+OnRevertedCallbackAsync: Reverted.
 Run Log:
 [*time*][Op1]: Start Executing Op1
 [*time*][Op1]: Registering reminder Op1:Retry for Op1 with interval 00:00:02
@@ -53,4 +53,5 @@ OnSagaCompleted: Id: test Status: Reverted
 3: RetryAttempt - SagaID: test, Operation: Op1, Attempt: 1
 4: StartOperation - SagaID: test, Operation: Op1
 5: EndOperation - SagaID: test, Operation: Op1, Outcome: Failed
-6: EndSaga - SagaID: test, Outcome: Reverted
+6: CustomEvent - SagaID: test, Event: SagaFailure, Properties: None
+7: EndSaga - SagaID: test, Outcome: Reverted
diff --git a/Sagaway.Tests/ApprovalFiles/test_single_long_wait_validate_false_with_revert.approved.txt b/Sagaway.Tests/ApprovalFiles/test_single_long_wait_validate_false_with_revert.approved.txt
index 09cc0e5..4102fba 100644
--- a/Sagaway.Tests/ApprovalFiles/test_single_long_wait_validate_false_with_revert.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_single_long_wait_validate_false_with_revert.approved.txt
@@ -31,7 +31,7 @@ Calling Op1: Success False
 Op1 Validate returns False
 Calling revert for Op1: Success False
 Calling revert for Op1: Success True
-OnRevertedCallback: Reverted.
+OnRevertedCallbackAsync: Reverted.
 Run Log:
 [*time*][Op1]: Start Executing Op1
 [*time*][Op1]: Registering reminder Op1:Retry for Op1 with interval 00:00:02
@@ -63,4 +63,5 @@ OnSagaCompleted: Id: test Status: Reverted
 7: RetryAttempt - SagaID: test, Operation: RevertOp1, Attempt: 1
 8: StartOperation - SagaID: test, Operation: RevertOp1
 9: EndOperation - SagaID: test, Operation: RevertOp1, Outcome: Reverted
-10: EndSaga - SagaID: test, Outcome: Reverted
+10: CustomEvent - SagaID: test, Event: SagaFailure, Properties: None
+11: EndSaga - SagaID: test, Outcome: Reverted
diff --git a/Sagaway.Tests/ApprovalFiles/test_single_long_wait_validate_false_with_revert_exception.approved.txt b/Sagaway.Tests/ApprovalFiles/test_single_long_wait_validate_false_with_revert_exception.approved.txt
index 58206aa..a7cd56a 100644
--- a/Sagaway.Tests/ApprovalFiles/test_single_long_wait_validate_false_with_revert_exception.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_single_long_wait_validate_false_with_revert_exception.approved.txt
@@ -35,7 +35,7 @@ Op1 Validate returns False
 Calling revert for Op1: Success False
 Calling revert for Op1: Success False
 Calling revert for Op1: Success True
-OnRevertedCallback: Reverted.
+OnRevertedCallbackAsync: Reverted.
 Run Log:
 [*time*][Op1]: Start Executing Op1
 [*time*][Op1]: Registering reminder Op1:Retry for Op1 with interval 00:00:02
@@ -72,4 +72,5 @@ OnSagaCompleted: Id: test Status: Reverted
 9: RetryAttempt - SagaID: test, Operation: RevertOp1, Attempt: 2
 10: StartOperation - SagaID: test, Operation: RevertOp1
 11: EndOperation - SagaID: test, Operation: RevertOp1, Outcome: Reverted
-12: EndSaga - SagaID: test, Outcome: Reverted
+12: CustomEvent - SagaID: test, Event: SagaFailure, Properties: None
+13: EndSaga - SagaID: test, Outcome: Reverted
diff --git a/Sagaway.Tests/ApprovalFiles/test_single_long_wait_validate_false_with_revert_fails.approved.txt b/Sagaway.Tests/ApprovalFiles/test_single_long_wait_validate_false_with_revert_fails.approved.txt
index 829427f..823889a 100644
--- a/Sagaway.Tests/ApprovalFiles/test_single_long_wait_validate_false_with_revert_fails.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_single_long_wait_validate_false_with_revert_fails.approved.txt
@@ -31,7 +31,7 @@ Calling Op1: Success False
 Op1 Validate returns False
 Calling revert for Op1: Success False
 Calling revert for Op1: Success False
-OnFailedRevertedCallback: FailedReverted.
+OnFailedRevertedCallbackAsync: FailedReverted.
 Run Log:
 [*time*][Op1]: Start Executing Op1
 [*time*][Op1]: Registering reminder Op1:Retry for Op1 with interval 00:00:02
@@ -63,4 +63,5 @@ OnSagaCompleted: Id: test Status: RevertFailed
 7: RetryAttempt - SagaID: test, Operation: RevertOp1, Attempt: 1
 8: StartOperation - SagaID: test, Operation: RevertOp1
 9: EndOperation - SagaID: test, Operation: RevertOp1, Outcome: RevertFailed
-10: EndSaga - SagaID: test, Outcome: PartiallyReverted
+10: CustomEvent - SagaID: test, Event: SagaFailure, Properties: None
+11: EndSaga - SagaID: test, Outcome: PartiallyReverted
diff --git a/Sagaway.Tests/ApprovalFiles/test_single_long_wait_validate_true.approved.txt b/Sagaway.Tests/ApprovalFiles/test_single_long_wait_validate_true.approved.txt
index b6fb268..01013dc 100644
--- a/Sagaway.Tests/ApprovalFiles/test_single_long_wait_validate_true.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_single_long_wait_validate_true.approved.txt
@@ -27,7 +27,7 @@ HasRevertValidate: False
 
 Calling Op1: Success True
 Op1 Validate returns True
-OnSuccessCompletionCallback: Success.
+OnSuccessCompletionCallbackAsync: Success.
 Run Log:
 [*time*][Op1]: Start Executing Op1
 [*time*][Op1]: Registering reminder Op1:Retry for Op1 with interval 00:00:02
diff --git a/Sagaway.Tests/ApprovalFiles/test_single_success.approved.txt b/Sagaway.Tests/ApprovalFiles/test_single_success.approved.txt
index 8bc5b5d..e4e0f4d 100644
--- a/Sagaway.Tests/ApprovalFiles/test_single_success.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_single_success.approved.txt
@@ -26,7 +26,7 @@ HasValidate: False
 HasRevertValidate: False
 
 Calling Op1: Success True
-OnSuccessCompletionCallback: Success.
+OnSuccessCompletionCallbackAsync: Success.
 Run Log:
 [*time*][Op1]: Start Executing Op1
 [*time*][Op1]: Op1 Success
diff --git a/Sagaway.Tests/ApprovalFiles/test_single_throw_exception.approved.txt b/Sagaway.Tests/ApprovalFiles/test_single_throw_exception.approved.txt
index bb29ef1..a104849 100644
--- a/Sagaway.Tests/ApprovalFiles/test_single_throw_exception.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_single_throw_exception.approved.txt
@@ -25,7 +25,7 @@ HasRevert: False
 HasValidate: False
 HasRevertValidate: False
 
-OnRevertedCallback: Reverted.
+OnRevertedCallbackAsync: Reverted.
 Run Log:
 [*time*][Op1]: Start Executing Op1
 [*time*][Op1]: Error when calling Op1. Error: Throwing exception on call 1. Retry in 00:00:00 seconds
@@ -42,4 +42,5 @@ OnSagaCompleted: Id: test Status: Reverted
 2: StartOperation - SagaID: test, Operation: Op1
 3: Exception - SagaID: test, Context: Error when calling Op1, Exception: Throwing exception on call 1
 4: EndOperation - SagaID: test, Operation: Op1, Outcome: Failed
-5: EndSaga - SagaID: test, Outcome: Reverted
+5: CustomEvent - SagaID: test, Event: SagaFailure, Properties: None
+6: EndSaga - SagaID: test, Outcome: Reverted
diff --git a/Sagaway.Tests/ApprovalFiles/test_single_throw_exception_and_exponential_retry.approved.txt b/Sagaway.Tests/ApprovalFiles/test_single_throw_exception_and_exponential_retry.approved.txt
index 2cd7f16..53bce8a 100644
--- a/Sagaway.Tests/ApprovalFiles/test_single_throw_exception_and_exponential_retry.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_single_throw_exception_and_exponential_retry.approved.txt
@@ -26,7 +26,7 @@ HasValidate: False
 HasRevertValidate: False
 
 Calling Op1: Success True
-OnSuccessCompletionCallback: Success.
+OnSuccessCompletionCallbackAsync: Success.
 Run Log:
 [*time*][Op1]: Start Executing Op1
 [*time*][Op1]: Registering reminder Op1:Retry for Op1 with interval 00:00:02
diff --git a/Sagaway.Tests/ApprovalFiles/test_single_throw_exception_and_retry.approved.txt b/Sagaway.Tests/ApprovalFiles/test_single_throw_exception_and_retry.approved.txt
index 9dbe1fc..f975a4a 100644
--- a/Sagaway.Tests/ApprovalFiles/test_single_throw_exception_and_retry.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_single_throw_exception_and_retry.approved.txt
@@ -26,7 +26,7 @@ HasValidate: False
 HasRevertValidate: False
 
 Calling Op1: Success True
-OnSuccessCompletionCallback: Success.
+OnSuccessCompletionCallbackAsync: Success.
 Run Log:
 [*time*][Op1]: Start Executing Op1
 [*time*][Op1]: Registering reminder Op1:Retry for Op1 with interval 00:00:02
diff --git a/Sagaway.Tests/ApprovalFiles/test_single_throw_exception_report_fail.approved.txt b/Sagaway.Tests/ApprovalFiles/test_single_throw_exception_report_fail.approved.txt
index 0f7ba99..32a675a 100644
--- a/Sagaway.Tests/ApprovalFiles/test_single_throw_exception_report_fail.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_single_throw_exception_report_fail.approved.txt
@@ -25,7 +25,7 @@ HasRevert: False
 HasValidate: False
 HasRevertValidate: False
 
-OnFailCallback: Fail.
+OnFailedCallbackAsync: Fail.
 Run Log:
 [*time*][Op1]: Start Executing Op1
 [*time*][Op1]: Error when calling Op1. Error: Throwing exception on call 1. Retry in 00:00:00 seconds
diff --git a/Sagaway.Tests/ApprovalFiles/test_single_throw_exception_twice_and_retry_three_times.approved.txt b/Sagaway.Tests/ApprovalFiles/test_single_throw_exception_twice_and_retry_three_times.approved.txt
index da4f747..c5d665c 100644
--- a/Sagaway.Tests/ApprovalFiles/test_single_throw_exception_twice_and_retry_three_times.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_single_throw_exception_twice_and_retry_three_times.approved.txt
@@ -27,7 +27,7 @@ HasValidate: False
 HasRevertValidate: False
 
 Calling Op1: Success True
-OnSuccessCompletionCallback: Success.
+OnSuccessCompletionCallbackAsync: Success.
 Run Log:
 [*time*][Op1]: Start Executing Op1
 [*time*][Op1]: Registering reminder Op1:Retry for Op1 with interval 00:00:02
diff --git a/Sagaway.Tests/ApprovalFiles/test_two_both_failed_revert_fails_2_times.approved.txt b/Sagaway.Tests/ApprovalFiles/test_two_both_failed_revert_fails_2_times.approved.txt
index 0bfa2aa..aee8e4a 100644
--- a/Sagaway.Tests/ApprovalFiles/test_two_both_failed_revert_fails_2_times.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_two_both_failed_revert_fails_2_times.approved.txt
@@ -55,7 +55,7 @@ Calling Op1: Success False
 Calling revert for Op1: Success False
 Calling revert for Op1: Success False
 Calling revert for Op1: Success True
-OnRevertedCallback: Reverted.
+OnRevertedCallbackAsync: Reverted.
 Run Log:
 [*time*][Op1]: Start Executing Op1
 [*time*][Op1]: Op1 Failed. Retries exhausted.
@@ -83,4 +83,5 @@ OnSagaCompleted: Id: test Status: Reverted
 7: RetryAttempt - SagaID: test, Operation: RevertOp1, Attempt: 2
 8: StartOperation - SagaID: test, Operation: RevertOp1
 9: EndOperation - SagaID: test, Operation: RevertOp1, Outcome: Reverted
-10: EndSaga - SagaID: test, Outcome: Reverted
+10: CustomEvent - SagaID: test, Event: SagaFailure, Properties: None
+11: EndSaga - SagaID: test, Outcome: Reverted
diff --git a/Sagaway.Tests/ApprovalFiles/test_two_first_deactivate_saga.approved.txt b/Sagaway.Tests/ApprovalFiles/test_two_first_deactivate_saga.approved.txt
index bb0aec7..65512fe 100644
--- a/Sagaway.Tests/ApprovalFiles/test_two_first_deactivate_saga.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_two_first_deactivate_saga.approved.txt
@@ -54,7 +54,7 @@ HasRevertValidate: False
 Calling Op1: Success True
 Op1 Validate returns True
 Calling Op2: Success True
-OnSuccessCompletionCallback: Success.
+OnSuccessCompletionCallbackAsync: Success.
 Run Log:
 [*time*][Op1]: Start Executing Op1
 [*time*][Op1]: Registering reminder Op1:Retry for Op1 with interval 00:00:01
diff --git a/Sagaway.Tests/ApprovalFiles/test_two_first_failed_fast_after_running_second.approved.txt b/Sagaway.Tests/ApprovalFiles/test_two_first_failed_fast_after_running_second.approved.txt
index b9055d9..2e61a47 100644
--- a/Sagaway.Tests/ApprovalFiles/test_two_first_failed_fast_after_running_second.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_two_first_failed_fast_after_running_second.approved.txt
@@ -54,7 +54,7 @@ Set to fail fast
 
 Calling Op2: Success True
 Calling Op1: Success True
-OnRevertedCallback: Reverted.
+OnRevertedCallbackAsync: Reverted.
 Run Log:
 [*time*][Op2]: Start Executing Op2
 [*time*][Op2]: Op2 Success
@@ -74,4 +74,5 @@ OnSagaCompleted: Id: test Status: Reverted
 3: EndOperation - SagaID: test, Operation: Op2, Outcome: Succeeded
 4: StartOperation - SagaID: test, Operation: Op1
 5: EndOperation - SagaID: test, Operation: Op1, Outcome: Failed
-6: EndSaga - SagaID: test, Outcome: Reverted
+6: CustomEvent - SagaID: test, Event: SagaFailure, Properties: None
+7: EndSaga - SagaID: test, Outcome: Reverted
diff --git a/Sagaway.Tests/ApprovalFiles/test_two_first_fast_succeeded_second_not_run.approved.txt b/Sagaway.Tests/ApprovalFiles/test_two_first_fast_succeeded_second_not_run.approved.txt
index 3d501fd..004813b 100644
--- a/Sagaway.Tests/ApprovalFiles/test_two_first_fast_succeeded_second_not_run.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_two_first_fast_succeeded_second_not_run.approved.txt
@@ -53,7 +53,7 @@ HasValidate: False
 HasRevertValidate: False
 
 Calling Op1: Success True
-OnSuccessCompletionCallback: Success.
+OnSuccessCompletionCallbackAsync: Success.
 Run Log:
 [*time*][Op1]: Start Executing Op1
 [*time*][Op1]: Op1 Success
diff --git a/Sagaway.Tests/ApprovalFiles/test_two_first_success_second_fail_no_retry.approved.txt b/Sagaway.Tests/ApprovalFiles/test_two_first_success_second_fail_no_retry.approved.txt
index 69a7c49..e186735 100644
--- a/Sagaway.Tests/ApprovalFiles/test_two_first_success_second_fail_no_retry.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_two_first_success_second_fail_no_retry.approved.txt
@@ -53,7 +53,7 @@ HasRevertValidate: False
 
 Calling Op1: Success True
 Calling Op2: Success False
-OnRevertedCallback: Reverted.
+OnRevertedCallbackAsync: Reverted.
 Run Log:
 [*time*][Op1]: Start Executing Op1
 [*time*][Op1]: Op1 Success
@@ -73,4 +73,5 @@ OnSagaCompleted: Id: test Status: Reverted
 3: EndOperation - SagaID: test, Operation: Op1, Outcome: Succeeded
 4: StartOperation - SagaID: test, Operation: Op2
 5: EndOperation - SagaID: test, Operation: Op2, Outcome: Failed
-6: EndSaga - SagaID: test, Outcome: Reverted
+6: CustomEvent - SagaID: test, Event: SagaFailure, Properties: None
+7: EndSaga - SagaID: test, Outcome: Reverted
diff --git a/Sagaway.Tests/ApprovalFiles/test_two_first_success_second_fail_no_retry_report_failure.approved.txt b/Sagaway.Tests/ApprovalFiles/test_two_first_success_second_fail_no_retry_report_failure.approved.txt
index 312e438..dec12ff 100644
--- a/Sagaway.Tests/ApprovalFiles/test_two_first_success_second_fail_no_retry_report_failure.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_two_first_success_second_fail_no_retry_report_failure.approved.txt
@@ -53,7 +53,7 @@ HasRevertValidate: False
 
 Calling Op1: Success True
 Calling Op2: Success False
-OnFailCallback: Fail.
+OnFailedCallbackAsync: Fail.
 Run Log:
 [*time*][Op1]: Start Executing Op1
 [*time*][Op1]: Op1 Success
diff --git a/Sagaway.Tests/ApprovalFiles/test_two_long_wait_validate_exception.approved.txt b/Sagaway.Tests/ApprovalFiles/test_two_long_wait_validate_exception.approved.txt
index 82d2e54..3918c9b 100644
--- a/Sagaway.Tests/ApprovalFiles/test_two_long_wait_validate_exception.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_two_long_wait_validate_exception.approved.txt
@@ -28,7 +28,7 @@ HasRevertValidate: False
 Calling Op1: Success True
 Calling Op1: Success True
 Op1 Validate returns False
-OnRevertedCallback: Reverted.
+OnRevertedCallbackAsync: Reverted.
 Run Log:
 [*time*][Op1]: Start Executing Op1
 [*time*][Op1]: Registering reminder Op1:Retry for Op1 with interval 00:00:02
@@ -53,4 +53,5 @@ OnSagaCompleted: Id: test Status: Reverted
 3: RetryAttempt - SagaID: test, Operation: Op1, Attempt: 1
 4: StartOperation - SagaID: test, Operation: Op1
 5: EndOperation - SagaID: test, Operation: Op1, Outcome: Failed
-6: EndSaga - SagaID: test, Outcome: Reverted
+6: CustomEvent - SagaID: test, Event: SagaFailure, Properties: None
+7: EndSaga - SagaID: test, Outcome: Reverted
diff --git a/Sagaway.Tests/ApprovalFiles/test_two_long_wait_validate_false_with_revert_exception.approved.txt b/Sagaway.Tests/ApprovalFiles/test_two_long_wait_validate_false_with_revert_exception.approved.txt
index dfe7c1a..bf79cc2 100644
--- a/Sagaway.Tests/ApprovalFiles/test_two_long_wait_validate_false_with_revert_exception.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_two_long_wait_validate_false_with_revert_exception.approved.txt
@@ -62,7 +62,7 @@ Op2 Validate returns False
 Calling revert for Op2: Success False
 Calling revert for Op2: Success False
 Calling revert for Op2: Success False
-OnFailedRevertedCallback: FailedReverted.
+OnFailedRevertedCallbackAsync: FailedReverted.
 Run Log:
 [*time*][Op1]: Start Executing Op1
 [*time*][Op1]: Op1 Success
@@ -105,4 +105,5 @@ OnSagaCompleted: Id: test Status: RevertFailed
 11: RetryAttempt - SagaID: test, Operation: RevertOp2, Attempt: 2
 12: StartOperation - SagaID: test, Operation: RevertOp2
 13: EndOperation - SagaID: test, Operation: RevertOp2, Outcome: RevertFailed
-14: EndSaga - SagaID: test, Outcome: PartiallyReverted
+14: CustomEvent - SagaID: test, Event: SagaFailure, Properties: None
+15: EndSaga - SagaID: test, Outcome: PartiallyReverted
diff --git a/Sagaway.Tests/ApprovalFiles/test_two_ops_throw_exception_on_first.approved.txt b/Sagaway.Tests/ApprovalFiles/test_two_ops_throw_exception_on_first.approved.txt
index cd2feab..57af7a9 100644
--- a/Sagaway.Tests/ApprovalFiles/test_two_ops_throw_exception_on_first.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_two_ops_throw_exception_on_first.approved.txt
@@ -51,7 +51,7 @@ HasRevert: False
 HasValidate: False
 HasRevertValidate: False
 
-OnRevertedCallback: Reverted.
+OnRevertedCallbackAsync: Reverted.
 Run Log:
 [*time*][Op1]: Start Executing Op1
 [*time*][Op1]: Error when calling Op1. Error: Throwing exception on call 1. Retry in 00:00:00 seconds
@@ -69,4 +69,5 @@ OnSagaCompleted: Id: test Status: Reverted
 2: StartOperation - SagaID: test, Operation: Op1
 3: Exception - SagaID: test, Context: Error when calling Op1, Exception: Throwing exception on call 1
 4: EndOperation - SagaID: test, Operation: Op1, Outcome: Failed
-5: EndSaga - SagaID: test, Outcome: Reverted
+5: CustomEvent - SagaID: test, Event: SagaFailure, Properties: None
+6: EndSaga - SagaID: test, Outcome: Reverted
diff --git a/Sagaway.Tests/ApprovalFiles/test_two_ops_throw_exception_on_second.approved.txt b/Sagaway.Tests/ApprovalFiles/test_two_ops_throw_exception_on_second.approved.txt
index 383dcd1..3b2ccd9 100644
--- a/Sagaway.Tests/ApprovalFiles/test_two_ops_throw_exception_on_second.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_two_ops_throw_exception_on_second.approved.txt
@@ -52,7 +52,7 @@ HasValidate: False
 HasRevertValidate: False
 
 Calling Op1: Success True
-OnRevertedCallback: Reverted.
+OnRevertedCallbackAsync: Reverted.
 Run Log:
 [*time*][Op1]: Start Executing Op1
 [*time*][Op1]: Op1 Success
@@ -75,4 +75,5 @@ OnSagaCompleted: Id: test Status: Reverted
 4: StartOperation - SagaID: test, Operation: Op2
 5: Exception - SagaID: test, Context: Error when calling Op2, Exception: Throwing exception on call 1
 6: EndOperation - SagaID: test, Operation: Op2, Outcome: Failed
-7: EndSaga - SagaID: test, Outcome: Reverted
+7: CustomEvent - SagaID: test, Event: SagaFailure, Properties: None
+8: EndSaga - SagaID: test, Outcome: Reverted
diff --git a/Sagaway.Tests/ApprovalFiles/test_two_second_failed_first_depends_on_first.approved.txt b/Sagaway.Tests/ApprovalFiles/test_two_second_failed_first_depends_on_first.approved.txt
index 63d141c..a484809 100644
--- a/Sagaway.Tests/ApprovalFiles/test_two_second_failed_first_depends_on_first.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_two_second_failed_first_depends_on_first.approved.txt
@@ -52,7 +52,7 @@ HasValidate: False
 HasRevertValidate: False
 
 Calling Op2: Success False
-OnRevertedCallback: Reverted.
+OnRevertedCallbackAsync: Reverted.
 Run Log:
 [*time*][Op2]: Start Executing Op2
 [*time*][Op2]: Op2 Failed. Retries exhausted.
@@ -67,4 +67,5 @@ OnSagaCompleted: Id: test Status: Reverted
 1: StartSaga - SagaID: test, Type: SagaOperations
 2: StartOperation - SagaID: test, Operation: Op2
 3: EndOperation - SagaID: test, Operation: Op2, Outcome: Failed
-4: EndSaga - SagaID: test, Outcome: Reverted
+4: CustomEvent - SagaID: test, Event: SagaFailure, Properties: None
+5: EndSaga - SagaID: test, Outcome: Reverted
diff --git a/Sagaway.Tests/ApprovalFiles/test_two_second_failed_first_fast_second.approved.txt b/Sagaway.Tests/ApprovalFiles/test_two_second_failed_first_fast_second.approved.txt
index 6270f41..e56d061 100644
--- a/Sagaway.Tests/ApprovalFiles/test_two_second_failed_first_fast_second.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_two_second_failed_first_fast_second.approved.txt
@@ -53,7 +53,7 @@ HasValidate: False
 HasRevertValidate: False
 
 Calling Op2: Success True
-OnRevertedCallback: Reverted.
+OnRevertedCallbackAsync: Reverted.
 Run Log:
 [*time*][Op2]: Start Executing Op2
 [*time*][Op2]: Op2 Failed Fast.
@@ -68,4 +68,5 @@ OnSagaCompleted: Id: test Status: Reverted
 1: StartSaga - SagaID: test, Type: SagaOperations
 2: StartOperation - SagaID: test, Operation: Op2
 3: EndOperation - SagaID: test, Operation: Op2, Outcome: Failed
-4: EndSaga - SagaID: test, Outcome: Reverted
+4: CustomEvent - SagaID: test, Event: SagaFailure, Properties: None
+5: EndSaga - SagaID: test, Outcome: Reverted
diff --git a/Sagaway.Tests/ApprovalFiles/test_two_success_after_5_retries.approved.txt b/Sagaway.Tests/ApprovalFiles/test_two_success_after_5_retries.approved.txt
index a02e439..b425eda 100644
--- a/Sagaway.Tests/ApprovalFiles/test_two_success_after_5_retries.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_two_success_after_5_retries.approved.txt
@@ -61,7 +61,7 @@ Calling Op2: Success False
 Calling Op2: Success False
 Calling Op2: Success False
 Calling Op2: Success True
-OnSuccessCompletionCallback: Success.
+OnSuccessCompletionCallbackAsync: Success.
 Run Log:
 [*time*][Op1]: Start Executing Op1
 [*time*][Op1]: Registering reminder Op1:Retry for Op1 with interval 00:00:01
diff --git a/Sagaway.Tests/ApprovalFiles/test_two_throw_exception_and_retry.approved.txt b/Sagaway.Tests/ApprovalFiles/test_two_throw_exception_and_retry.approved.txt
index dfffa11..f24af5a 100644
--- a/Sagaway.Tests/ApprovalFiles/test_two_throw_exception_and_retry.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_two_throw_exception_and_retry.approved.txt
@@ -53,7 +53,7 @@ HasRevertValidate: False
 
 Calling Op1: Success True
 Calling Op2: Success True
-OnSuccessCompletionCallback: Success.
+OnSuccessCompletionCallbackAsync: Success.
 Run Log:
 [*time*][Op1]: Start Executing Op1
 [*time*][Op1]: Registering reminder Op1:Retry for Op1 with interval 00:00:02
diff --git a/Sagaway.Tests/ApprovalFiles/test_two_throw_exception_twice_and_retry_three_times.approved.txt b/Sagaway.Tests/ApprovalFiles/test_two_throw_exception_twice_and_retry_three_times.approved.txt
index 169d2ff..0ecad46 100644
--- a/Sagaway.Tests/ApprovalFiles/test_two_throw_exception_twice_and_retry_three_times.approved.txt
+++ b/Sagaway.Tests/ApprovalFiles/test_two_throw_exception_twice_and_retry_three_times.approved.txt
@@ -55,7 +55,7 @@ HasRevertValidate: False
 
 Calling Op1: Success True
 Calling Op2: Success True
-OnSuccessCompletionCallback: Success.
+OnSuccessCompletionCallbackAsync: Success.
 Run Log:
 [*time*][Op1]: Start Executing Op1
 [*time*][Op1]: Registering reminder Op1:Retry for Op1 with interval 00:00:01
diff --git a/Sagaway.Tests/Tests.cs b/Sagaway.Tests/Tests.cs
index cd35c5f..8d506ae 100644
--- a/Sagaway.Tests/Tests.cs
+++ b/Sagaway.Tests/Tests.cs
@@ -106,8 +106,11 @@ public void TestValidationNoOperation()
             // ReSharper disable once UnusedVariable
             var builder = Saga<Operations>.Create("test", new SagaTestHost(ReminderCallBack), _logger)
              .WithOnSuccessCompletionCallback(_ => { })
+             .WithOnSuccessCompletionCallbackAsync(_ => Task.CompletedTask)
              .WithOnRevertedCallback(_ => { })
+             .WithOnRevertedCallbackAsync(_ => Task.CompletedTask)
              .WithOnFailedRevertedCallback(_ => { })
+             .WithOnFailedRevertedCallbackAsync(_ => Task.CompletedTask)
              .Build();
         }
         catch (Exception ex)
@@ -128,7 +131,9 @@ public void TestValidationNoOnSuccessCompletionCallback()
             // ReSharper disable once UnusedVariable
             var builder = Saga<Operations>.Create("test", new SagaTestHost(ReminderCallBack), _logger)
              .WithOnRevertedCallback(_ => { })
+             .WithOnRevertedCallbackAsync(_ => Task.CompletedTask)
              .WithOnFailedRevertedCallback(_ => { })
+             .WithOnFailedRevertedCallbackAsync(_ => Task.CompletedTask)
              .WithOperation(Operations.Op1)
              .WithDoOperation(() => Task.CompletedTask)
              .Build();
@@ -151,7 +156,9 @@ public void TestValidationNoOnRevertedCallback()
             // ReSharper disable once UnusedVariable
             var builder = Saga<Operations>.Create("test", new SagaTestHost(ReminderCallBack), _logger)
              .WithOnSuccessCompletionCallback(_ => { })
+             .WithOnSuccessCompletionCallbackAsync(_ => Task.CompletedTask)
              .WithOnFailedRevertedCallback(_ => { })
+             .WithOnFailedRevertedCallbackAsync(_ => Task.CompletedTask)
              .WithOperation(Operations.Op1)
              .WithDoOperation(() => Task.CompletedTask)
              .Build();
@@ -174,7 +181,9 @@ public void TestValidationNoOnFailedRevertedCallback()
             // ReSharper disable once UnusedVariable
             var builder = Saga<Operations>.Create("test", new SagaTestHost(ReminderCallBack), _logger)
              .WithOnSuccessCompletionCallback(_ => { })
+             .WithOnSuccessCompletionCallbackAsync(_ => Task.CompletedTask)
              .WithOnRevertedCallback(_ => { })
+             .WithOnRevertedCallbackAsync(_ => Task.CompletedTask)
              .WithOperation(Operations.Op1)
              .WithDoOperation(() => Task.CompletedTask)
              .Build();
@@ -197,8 +206,11 @@ public void TestValidationOperationNoDoOperation()
             // ReSharper disable once UnusedVariable
             var builder = Saga<Operations>.Create("test", new SagaTestHost(ReminderCallBack), _logger)
              .WithOnSuccessCompletionCallback(_ => { })
+             .WithOnSuccessCompletionCallbackAsync(_ => Task.CompletedTask)
              .WithOnRevertedCallback(_ => { })
+             .WithOnRevertedCallbackAsync(_ => Task.CompletedTask)
              .WithOnFailedRevertedCallback(_ => { })
+             .WithOnFailedRevertedCallbackAsync(_ => Task.CompletedTask)
              .WithOperation(Operations.Op1)
              .Build();
         }
@@ -291,18 +303,54 @@ private async Task TestRunAsync(string testName, params string[] operations)
         var sb = new StringBuilder();
         sb.AppendLine($"Preparing test {testName}");
 
-        builder.WithOnSuccessCompletionCallback(log => sb.AppendLine($"OnSuccessCompletionCallback: Success.{Environment.NewLine}Run Log:{Environment.NewLine}" + log + Environment.NewLine));
+        // Register both synchronous and asynchronous callbacks with sb.AppendLine included directly
+        builder
+            .WithOnSuccessCompletionCallback(log =>
+            {
+                sb.AppendLine($"OnSuccessCompletionCallback: Success.{Environment.NewLine}Run Log:{Environment.NewLine}" + log + Environment.NewLine);
+            })
+            .WithOnSuccessCompletionCallbackAsync(async log =>
+            {
+                sb.AppendLine($"OnSuccessCompletionCallbackAsync: Success.{Environment.NewLine}Run Log:{Environment.NewLine}" + log + Environment.NewLine);
+                await Task.CompletedTask; // If no asynchronous operation, use Task.CompletedTask
+            });
 
         var buildOperations = BuildTestOperations(operations).ToList();
         
         if (buildOperations.Any(o => o.HasReportFail))
         {
-            builder.WithOnFailedCallback(log => sb.AppendLine($"OnFailCallback: Fail.{Environment.NewLine}Run Log:{Environment.NewLine}" + log + Environment.NewLine));
-        }
+            builder
+                .WithOnFailedCallback(log =>
+                {
+                    sb.AppendLine($"OnFailedCallback: Fail.{Environment.NewLine}Run Log:{Environment.NewLine}" + log + Environment.NewLine);
+                })
+                .WithOnFailedCallbackAsync(async log =>
+                {
+                    sb.AppendLine($"OnFailedCallbackAsync: Fail.{Environment.NewLine}Run Log:{Environment.NewLine}" + log + Environment.NewLine);
+                    await Task.CompletedTask;
+                });
+            }
         else
         {
-            builder.WithOnRevertedCallback(log => sb.AppendLine($"OnRevertedCallback: Reverted.{Environment.NewLine}Run Log:{Environment.NewLine}" + log + Environment.NewLine))
-            .WithOnFailedRevertedCallback(log => sb.AppendLine($"OnFailedRevertedCallback: FailedReverted.{Environment.NewLine}Run Log:{Environment.NewLine}" + log + Environment.NewLine));
+            builder
+                .WithOnRevertedCallback(log =>
+                {
+                    sb.AppendLine($"OnRevertedCallback: Reverted.{Environment.NewLine}Run Log:{Environment.NewLine}" + log + Environment.NewLine);
+                })
+                .WithOnRevertedCallbackAsync(async log =>
+                {
+                    sb.AppendLine($"OnRevertedCallbackAsync: Reverted.{Environment.NewLine}Run Log:{Environment.NewLine}" + log + Environment.NewLine);
+                    await Task.CompletedTask;
+                })
+                .WithOnFailedRevertedCallback(log =>
+                {
+                    sb.AppendLine($"OnFailedRevertedCallback: FailedReverted.{Environment.NewLine}Run Log:{Environment.NewLine}" + log + Environment.NewLine);
+                })
+                .WithOnFailedRevertedCallbackAsync(async log =>
+                {
+                    sb.AppendLine($"OnFailedRevertedCallbackAsync: FailedReverted.{Environment.NewLine}Run Log:{Environment.NewLine}" + log + Environment.NewLine);
+                    await Task.CompletedTask;
+                });
         }
 
         foreach (var testOperation in buildOperations)
diff --git a/Sagaway/Saga.cs b/Sagaway/Saga.cs
index 7c81134..fa86726 100644
--- a/Sagaway/Saga.cs
+++ b/Sagaway/Saga.cs
@@ -19,9 +19,13 @@ public partial class Saga<TEOperations> : ISagaReset, ISaga<TEOperations> where
     private ILogger _logger;
     private readonly ISagaSupport _sagaSupportOperations;
     private readonly Action<string>? _onSuccessCallback;
+    private readonly Func<string, Task>? _onSuccessCallbackAsync;
     private readonly Action<string>? _onFailedCallback;
+    private readonly Func<string, Task>? _onFailedCallbackAsync;
     private readonly Action<string>? _onRevertedCallback;
+    private readonly Func<string, Task>? _onRevertedCallbackAsync;
     private readonly Action<string>? _onRevertFailureCallback;
+    private readonly Func<string, Task>? _onRevertFailureCallbackAsync;
     private bool _deactivated;
     private readonly ILockWrapper _lock;
     private bool _resetSagaState;
@@ -166,8 +170,8 @@ public async Task RecordTelemetryExceptionAsync(Exception exception, string? con
     #endregion //telemetry
 
     private Saga(ILogger logger, string sagaUniqueId, ISagaSupport sagaSupportOperations,
-        IReadOnlyList<SagaOperation> operations, Action<string>? onSuccessCallback, Action<string>? onFailedCallback,
-        Action<string>? onRevertedCallback, Action<string>? onRevertFailureCallback)
+        IReadOnlyList<SagaOperation> operations, Action<string>? onSuccessCallback, Func<string, Task>? onSuccessCallbackAsync, Action<string>? onFailedCallback,
+        Func<string, Task>? onFailedCallbackAsync, Action<string>? onRevertedCallback, Func<string, Task>? onRevertedCallbackAsync, Action<string>? onRevertFailureCallback,Func<string, Task>? onRevertFailureCallbackAsync)
     {
         _logger = logger ?? throw new ArgumentNullException(nameof(logger));
 
@@ -175,9 +179,13 @@ private Saga(ILogger logger, string sagaUniqueId, ISagaSupport sagaSupportOperat
         _sagaSupportOperations = sagaSupportOperations;
         _operations = operations.Select(o => new SagaOperationExecution(this, o, logger)).ToList();
         _onSuccessCallback = onSuccessCallback;
+        _onSuccessCallbackAsync = onSuccessCallbackAsync;
         _onFailedCallback = onFailedCallback;
+        _onFailedCallbackAsync = onFailedCallbackAsync;
         _onRevertedCallback = onRevertedCallback;
+        _onRevertedCallbackAsync = onRevertedCallbackAsync;
         _onRevertFailureCallback = onRevertFailureCallback;
+        _onRevertFailureCallbackAsync = onRevertFailureCallbackAsync;
         _lock = _sagaSupportOperations.CreateLock();
 
         _logger.LogInformation("Created new Saga instance with ID {SagaId}", _sagaUniqueId);
@@ -623,12 +631,21 @@ private async Task CheckForCompletionAsync()
         {
             //Failed is a transient state, so the saga is not done reverting,
             //We ensure that we call the onFailedCallback only once
-            if (Failed && _onFailedCallback != null && !_hasFailedReported)
+            if (Failed && !_hasFailedReported)
             {
                 _logger.LogDebug("Saga {_sagaUniqueId} failed, calling onFailedCallback.", _sagaUniqueId);
 
                 _hasFailedReported = true;
-                _onFailedCallback(recordedSteps);
+
+                if (_onFailedCallbackAsync != null)
+                {
+                    await _onFailedCallbackAsync(recordedSteps);
+                }
+                else if (_onFailedCallback != null)
+                {
+                    _onFailedCallback(recordedSteps);
+                }
+
                 await TelemetryAdapter.RecordCustomEventAsync(_telemetryContext, "SagaFailure");
             }
 
@@ -643,23 +660,44 @@ private async Task CheckForCompletionAsync()
             }
 
             //first handle completion notification
-            if (Succeeded && _onSuccessCallback != null)
+            if (Succeeded)
             {
                 _logger.LogTrace("Saga {_sagaUniqueId} is succeeded, calling onSuccessCallback.", _sagaUniqueId);
 
-                _onSuccessCallback(recordedSteps);
+                if (_onSuccessCallbackAsync != null)
+                {
+                    await _onSuccessCallbackAsync(recordedSteps);
+                }
+                else if (_onSuccessCallback != null)
+                {
+                    _onSuccessCallback(recordedSteps);
+                }
             }
-            else if (Reverted && _onRevertedCallback != null)
+            else if (Reverted)
             {
                 _logger.LogTrace("Saga {_sagaUniqueId} is reverted, calling onRevertedCallback.", _sagaUniqueId);
 
-                _onRevertedCallback(recordedSteps);
+                if (_onRevertedCallbackAsync != null)
+                {
+                    await _onRevertedCallbackAsync(recordedSteps);
+                }
+                else if (_onRevertedCallback != null)
+                {
+                    _onRevertedCallback(recordedSteps);
+                }
             }
-            else if (RevertFailed && _onRevertFailureCallback != null)
+            else if (RevertFailed)
             {
                 _logger.LogTrace("Saga {_sagaUniqueId} is revert failed, calling onRevertFailureCallback.", _sagaUniqueId);
 
-                _onRevertFailureCallback(recordedSteps);
+                if (_onRevertFailureCallbackAsync != null)
+                {
+                    await _onRevertFailureCallbackAsync(recordedSteps);
+                }
+                else if (_onRevertFailureCallback != null)
+                {
+                    _onRevertFailureCallback(recordedSteps);
+                }
             }
         }
         catch (Exception ex)
diff --git a/Sagaway/Sagaway.Builder/SagaBuilder.cs b/Sagaway/Sagaway.Builder/SagaBuilder.cs
index 68bfcf7..988de0d 100644
--- a/Sagaway/Sagaway.Builder/SagaBuilder.cs
+++ b/Sagaway/Sagaway.Builder/SagaBuilder.cs
@@ -14,10 +14,15 @@ public partial class SagaBuilder
         private readonly ISagaSupport _sagaSupportOperations;
         private readonly ILogger _logger;
         private Action<string>? _onSuccessCompletionCallback;
+        private Func<string, Task>? _onSuccessCompletionCallbackAsync;
         private Action<string>? _onRevertedCallback;
+        private Func<string, Task>? _onRevertedCallbackAsync;
         private Action<string>? _onFailedRevertedCallback;
-        private readonly List<SagaOperation> _operations = new();
+        private Func<string, Task>? _onFailedRevertedCallbackAsync;
         private Action<string>? _onFailedCallback;
+        private Func<string, Task>? _onFailedCallbackAsync;
+        private readonly List<SagaOperation> _operations = new();
+       
 
         /// <summary>
         /// The saga fluent interface builder
@@ -43,6 +48,16 @@ public SagaBuilder WithOnSuccessCompletionCallback(Action<string> onSuccessCompl
             return this;
         }
 
+        /// <summary>
+        /// Add an asynchronous action that is called on success completion of the saga
+        /// </summary>
+        /// <param name="onSuccessCompletionCallbackAsync">The asynchronous callback function. Receives the complete saga log</param>
+        /// <returns>The saga builder for fluent build</returns>
+        public SagaBuilder WithOnSuccessCompletionCallbackAsync(Func<string, Task> onSuccessCompletionCallbackAsync)
+        {
+                _onSuccessCompletionCallbackAsync = onSuccessCompletionCallbackAsync;
+                return this;
+        }
 
         /// <summary>
         /// Add an action that is called on a failure of the saga before any compensation is handle, if exists
@@ -55,6 +70,17 @@ public SagaBuilder WithOnFailedCallback(Action<string> onFailedCallback)
             return this;
         }
 
+        /// <summary>
+        /// Add an asynchronous action that is called on a failure of the saga before any compensation is handled, if exists
+        /// </summary>
+        /// <param name="onFailedCallbackAsync">The asynchronous callback function. Receives the partial saga log</param>
+        /// <returns>The saga builder for fluent build</returns>
+        public SagaBuilder WithOnFailedCallbackAsync(Func<string, Task> onFailedCallbackAsync)
+        {
+            _onFailedCallbackAsync = onFailedCallbackAsync;
+            return this;
+        }
+
         /// <summary>
         /// Add an action that is called on a failure of the saga after all compensations (reverts) are done
         /// </summary>
@@ -68,6 +94,19 @@ public SagaBuilder WithOnRevertedCallback(Action<string> onRevertedCallback)
             return this;
         }
 
+        /// <summary>
+        /// Add an asynchronous action that is called on a failure of the saga after all compensations (reverts) are done
+        /// </summary>
+        /// <param name="onRevertedCallbackAsync">The asynchronous callback function. Receives the complete saga log</param>
+        /// <returns>The saga builder for fluent build</returns>
+        /// <remarks>At least one operation failed, all retries are done.  
+        /// The Saga has finished the compensation (revert) process</remarks>
+        public SagaBuilder WithOnRevertedCallbackAsync(Func<string, Task> onRevertedCallbackAsync)
+        {
+            _onRevertedCallbackAsync = onRevertedCallbackAsync;
+            return this;
+        }
+
         /// <summary>
         /// Add an action that is called on a failure in reverting the saga when doing compensations
         /// </summary>
@@ -81,6 +120,19 @@ public SagaBuilder WithOnFailedRevertedCallback(Action<string> onFailedRevertedC
             return this;
         }
 
+        /// <summary>
+        /// Add an asynchronous action that is called on a failure in reverting the saga when doing compensations
+        /// </summary>
+        /// <param name="onFailedRevertedCallbackAsync">The asynchronous callback function. Receives the saga log</param>
+        /// <returns>The saga builder for fluent build</returns>
+        /// <remarks>At least one operation failed, all retries are done, but at least one operation failed to revert.  
+        /// The Saga has finished the compensation (revert) process</remarks>
+        public SagaBuilder WithOnFailedRevertedCallbackAsync(Func<string, Task> onFailedRevertedCallbackAsync)
+        {
+            _onFailedRevertedCallbackAsync = onFailedRevertedCallbackAsync;
+            return this;
+        }
+
         /// <summary>
         /// Add an operation to the saga
         /// </summary>
@@ -102,7 +154,19 @@ private void AddOperation(SagaOperation operation)
         /// <returns>The saga instance</returns>
         public ISaga<TEOperations> Build()
         {
-            var saga = new Saga<TEOperations>(_logger, _sagaUniqueId, _sagaSupportOperations, _operations, _onSuccessCompletionCallback, _onFailedCallback ,_onRevertedCallback, _onFailedRevertedCallback);
+            var saga = new Saga<TEOperations>(
+                _logger, 
+                _sagaUniqueId, 
+                _sagaSupportOperations, 
+                _operations, 
+                _onSuccessCompletionCallback,
+                _onSuccessCompletionCallbackAsync,
+                _onFailedCallback,
+                _onFailedCallbackAsync,
+                _onRevertedCallback,
+                _onRevertedCallbackAsync, 
+                _onFailedRevertedCallback,
+                _onFailedRevertedCallbackAsync);
             return saga;
         }
     }