diff --git a/backend/app/services/subscription/unified_executor.py b/backend/app/services/subscription/unified_executor.py
index 6c1d39ae6..281ab2345 100644
--- a/backend/app/services/subscription/unified_executor.py
+++ b/backend/app/services/subscription/unified_executor.py
@@ -209,6 +209,47 @@ async def _execute_sse_sync(
             f"content_length={len(accumulated_content)}"
         )
 
+        # Build result from accumulated content or final_event
+        # Check if final_event is an error event
+        from shared.models import EventType
+
+        result = None
+        error_message = None
+        status = "COMPLETED"
+
+        if final_event and final_event.type == EventType.ERROR.value:
+            # Handle error event
+            status = "FAILED"
+            error_message = final_event.error or "Unknown error"
+            logger.warning(
+                f"[_execute_sse_sync] Error event received: "
+                f"execution_id={execution_data.execution_id}, error={error_message}"
+            )
+        elif accumulated_content:
+            result = {"value": accumulated_content}
+        elif final_event and final_event.result:
+            result = final_event.result
+
+        # Publish TaskCompletedEvent for unified handling
+        logger.info(
+            f"[_execute_sse_sync] About to publish TaskCompletedEvent: "
+            f"task_id={execution_data.task_id}, subtask_id={execution_data.subtask_id}, "
+            f"status={status}, execution_id={execution_data.execution_id}"
+        )
+        await event_bus.publish(
+            TaskCompletedEvent(
+                task_id=execution_data.task_id,
+                subtask_id=execution_data.subtask_id,
+                user_id=execution_data.user_id,
+                status=status,
+                result=result,
+                error=error_message,
+            )
+        )
+        logger.info(
+            f"[_execute_sse_sync] TaskCompletedEvent published successfully: "
+            f"execution_id={execution_data.execution_id}"
+        )
         # TaskCompletedEvent is published by StatusUpdatingEmitter
 
     except Exception as e:
@@ -275,6 +316,30 @@ async def _execute_http_callback(
         except Exception:
             pass  # Error already handled via emitter
 
+        # Check if final_event is an error event
+        from shared.models import EventType
+
+        if final_event and final_event.type == EventType.ERROR.value:
+            error_message = final_event.error or "Unknown error"
+            logger.error(
+                f"[_execute_http_callback] Error event received: "
+                f"execution_id={execution_data.execution_id}, error={error_message}"
+            )
+            # Publish TaskCompletedEvent with FAILED status
+            from app.core.events import TaskCompletedEvent, get_event_bus
+
+            event_bus = get_event_bus()
+            await event_bus.publish(
+                TaskCompletedEvent(
+                    task_id=execution_data.task_id,
+                    subtask_id=execution_data.subtask_id,
+                    user_id=execution_data.user_id,
+                    status="FAILED",
+                    error=error_message,
+                )
+            )
+            return
+
         logger.info(
             f"[_execute_http_callback] HTTP+Callback completed: "
             f"execution_id={execution_data.execution_id}, "