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core/engine.py

@@ -135,8 +135,10 @@ class WorkflowEngine:
         start_time = datetime.now()
         
         try:
+            # Convert enum to string value if needed
+            node_type = node.type.value if hasattr(node.type, 'value') else str(node.type)
             output = await self.node_executor.execute(
-                node.type,
+                node_type,
                 node.data.model_dump(),
                 state.variables
             )