diff --git a/packages/gen/gen_ai_hub/orchestration_v2/models/message.py b/packages/gen/gen_ai_hub/orchestration_v2/models/message.py
index d3b40d09..bac701c4 100644
--- a/packages/gen/gen_ai_hub/orchestration_v2/models/message.py
+++ b/packages/gen/gen_ai_hub/orchestration_v2/models/message.py
@@ -67,8 +67,8 @@ class ReasoningBlock(BaseModel):
         content: The reasoning content.
         signature: Signature string for hidden reasoning content.
     """
-    content: str
-    signature: str
+    content: Optional[str] = None
+    signature: Optional[str] = None