diff --git a/src/BuiltinExtensions/ComfyUIBackend/ComfyUIAPIAbstractBackend.cs b/src/BuiltinExtensions/ComfyUIBackend/ComfyUIAPIAbstractBackend.cs
index abf94e193..ff883adb1 100644
--- a/src/BuiltinExtensions/ComfyUIBackend/ComfyUIAPIAbstractBackend.cs
+++ b/src/BuiltinExtensions/ComfyUIBackend/ComfyUIAPIAbstractBackend.cs
@@ -516,7 +516,7 @@ async Task doInterruptNow()
                                     ["comfy_index"] = index
                                 };
                             }
-                            takeOutput(new T2IEngine.ImageOutput() { File = new Image(output[preBytes..], mediaType), IsReal = isReal, GenTimeMS = firstStep == 0 ? -1 : (Environment.TickCount64 - firstStep) });
+                            takeOutput(new T2IEngine.ImageOutput() { File = new Image(output[preBytes..], mediaType), IsReal = isReal, BackendInternalHint = currentNode, GenTimeMS = firstStep == 0 ? -1 : (Environment.TickCount64 - firstStep) });
                         }
                         else
                         {
diff --git a/src/Text2Image/T2IEngine.cs b/src/Text2Image/T2IEngine.cs
index c0fc4d84b..9c095f0d1 100644
--- a/src/Text2Image/T2IEngine.cs
+++ b/src/Text2Image/T2IEngine.cs
@@ -29,7 +29,7 @@ public record class PreGenerationEventParams(T2IParamInput UserInput);
         public static Action<PostGenerationEventParams> PostGenerateEvent;
 
         /// <summary>Paramters for <see cref="PostGenerateEvent"/>.</summary>
-        public record class PostGenerationEventParams(MediaFile File, T2IParamInput UserInput, Action RefuseImage);
+        public record class PostGenerationEventParams(MediaFile File, T2IParamInput UserInput, Action RefuseImage, string BackendInternalHint = null);
 
         /// <summary>Extension event, fired after a batch of images were generated.
         /// Use "RefuseImage" to mark an image as removed. Note that it may have already been shown to a user, when the live result websocket API is in use.</summary>
@@ -66,6 +66,9 @@ public Image Img
 
             /// <summary>An action that will remove/discard this file as relevant.</summary>
             public Action RefuseImage;
+
+            /// <summary>Optional text identifying some internal hint from the backend, such as a Comfy Node ID. Format or content not guaranteed, use with caution and validation checks.</summary>
+            public string BackendInternalHint;
         }
 
         /// <summary>List of functions that take a pair of userinput and backend, and returns true if they can fit together, or false if the pair is not valid (add to user_input.RefusalReasons if so).</summary>
@@ -221,7 +224,7 @@ string format(long t)
                     copyInput.ExtraMeta["intermediate"] = "intermediate output";
                 }
                 bool refuse = false;
-                PostGenerateEvent?.Invoke(new(img.File, copyInput, () => refuse = true));
+                PostGenerateEvent?.Invoke(new(img.File, copyInput, () => refuse = true, img.BackendInternalHint));
                 if (refuse)
                 {
                     Logs.Info($"Refused an image.");