[Bugfix] fix tool call arguments is empty (#25223)

Signed-off-by: chaunceyjiang <chaunceyjiang@gmail.com> Co-authored-by: xin.li <xin.li@daocloud.io>
2025-09-20 13:29:54 +08:00
parent 6c5f82e5aa
commit f91480b2d4
2 changed files with 65 additions and 3 deletions
--- a/vllm/entrypoints/chat_utils.py
+++ b/vllm/entrypoints/chat_utils.py
@@ -1450,9 +1450,11 @@ def _postprocess_messages(messages: list[ConversationMessage]) -> None:
            and isinstance(message["tool_calls"], list)
        ):
            for item in message["tool_calls"]:
-                item["function"]["arguments"] = json.loads(
-                    item["function"]["arguments"]
-                )
+                # if arguments is None or empty string, set to {}
+                if content := item["function"].get("arguments"):
+                    item["function"]["arguments"] = json.loads(content)
+                else:
+                    item["function"]["arguments"] = {}


 def parse_chat_messages(