diff --git a/py/metadata_collector/metadata_hook.py b/py/metadata_collector/metadata_hook.py
index f1931f7c..b9b40e09 100644
--- a/py/metadata_collector/metadata_hook.py
+++ b/py/metadata_collector/metadata_hook.py
@@ -83,7 +83,7 @@ class MetadataHook:
                         
                         # Record inputs before execution
                         if node_id is not None:
-                            return_types = getattr(obj.__class__, 'RETURN_TYPES', None)
+                            return_types = getattr(obj, 'RETURN_TYPES', None)
                             registry.record_node_execution(node_id, class_type, input_data_all, None, return_types=return_types)
                 except Exception as e:
                     logger.error(f"Error collecting metadata (pre-execution): {str(e)}")
@@ -115,7 +115,7 @@ class MetadataHook:
                         
                         # Record outputs after execution
                         if node_id is not None:
-                            return_types = getattr(obj.__class__, 'RETURN_TYPES', None)
+                            return_types = getattr(obj, 'RETURN_TYPES', None)
                             registry.update_node_execution(node_id, class_type, results, return_types=return_types)
                 except Exception as e:
                     logger.error(f"Error collecting metadata (post-execution): {str(e)}")
@@ -168,7 +168,7 @@ class MetadataHook:
                         class_type = obj.__class__.__name__
                         node_id = unique_id
                         if node_id is not None:
-                            return_types = getattr(obj.__class__, 'RETURN_TYPES', None)
+                            return_types = getattr(obj, 'RETURN_TYPES', None)
                             registry.record_node_execution(node_id, class_type, input_data_all, None, return_types=return_types)
                 except Exception as e:
                     logger.error(f"Error collecting metadata (pre-execution): {str(e)}")
@@ -186,7 +186,7 @@ class MetadataHook:
                         class_type = obj.__class__.__name__
                         node_id = unique_id
                         if node_id is not None:
-                            return_types = getattr(obj.__class__, 'RETURN_TYPES', None)
+                            return_types = getattr(obj, 'RETURN_TYPES', None)
                             registry.update_node_execution(node_id, class_type, results, return_types=return_types)
                 except Exception as e:
                     logger.error(f"Error collecting metadata (post-execution): {str(e)}")
diff --git a/py/metadata_collector/metadata_registry.py b/py/metadata_collector/metadata_registry.py
index e8caa4e2..856771b1 100644
--- a/py/metadata_collector/metadata_registry.py
+++ b/py/metadata_collector/metadata_registry.py
@@ -172,7 +172,7 @@ class MetadataRegistry:
 
         # Extract node-specific metadata
         extractor = NODE_EXTRACTORS.get(class_type, GenericNodeExtractor)
-        if type(extractor) is GenericNodeExtractor:
+        if extractor is GenericNodeExtractor:
             extractor.extract(node_id, processed_inputs, outputs,
                               self.prompt_metadata[self.current_prompt_id],
                               return_types=return_types)
@@ -194,7 +194,7 @@ class MetadataRegistry:
         # Use the same extractor to update with outputs
         extractor = NODE_EXTRACTORS.get(class_type, GenericNodeExtractor)
         if hasattr(extractor, "update"):
-            if type(extractor) is GenericNodeExtractor:
+            if extractor is GenericNodeExtractor:
                 extractor.update(
                     node_id, processed_outputs,
                     self.prompt_metadata[self.current_prompt_id],