diff --git a/oproof/serializer.py b/oproof/serializer.py
index ec7167c..e4e238c 100644
--- a/oproof/serializer.py
+++ b/oproof/serializer.py
@@ -6,16 +6,26 @@ def serialize_output(text: str, responses: List[Dict[str, Any]], include_prompts
         result = {
             "original_text": text,
             "responses": [
-                {
-                    "prompt": response.get("prompt", ""),
-                    "response": response.get("response", ""),
-                    "is_valid": response.get("is_valid", False),
-                    "domain": response.get("domain", "unknown"),
-                    "context": response.get("context", "unknown"),
-                    "reason": response.get("reason", "No reason provided"),
-                    "raw_response": response.get("raw_response", "") if include_prompts else None
-                }
+                Serializer._serialize_response(response, include_prompts)
                 for response in responses
             ]
         }
         return result
+
+    @staticmethod
+    def _serialize_response(response: Dict[str, Any], include_prompts: bool) -> Dict[str, Any]:
+        serialized_response = {
+            "prompt": response.get("prompt", ""),
+            "response": response.get("response", ""),
+            "is_valid": response.get("is_valid", False),
+            "domain": response.get("domain", "unknown"),
+            "context": response.get("context", "unknown")
+        }
+        
+        if response.get("reason") is not None:
+            serialized_response["reason"] = response.get("reason")
+        
+        if include_prompts and response.get("raw_response") is not None:
+            serialized_response["raw_response"] = response.get("raw_response")
+        
+        return serialized_response