vllm version: 0.19.0
OS: Ubuntu 22.04
GPU: 8 x NVIDIA H20-3e
Model: GLM-5.1-FP8 (zai-org/GLM-5.1)
Serve cmd:
  vllm serve /path/to/GLM-5.1-FP8 \
    --tensor-parallel-size 8 \
    --served-model-name GLM-5.1 \
    --reasoning-parser glm45 \
    --tool-call-parser glm47 \
    --enable-auto-tool-choice \
    --trust-remote-code

---

vllm serve zai-org/GLM-5.1 \
  --tensor-parallel-size 8 \
  --reasoning-parser glm45 \
  --tool-call-parser glm47 \
  --enable-auto-tool-choice

---

curl -s -N -X POST http://localhost:8000/v1/responses \
  -H "Content-Type: application/json" \
  -d '{
    "model":"zai-org/GLM-5.1",
    "input":"What is the weather in Beijing?",
    "tools":[{
      "type":"function",
      "name":"get_weather",
      "description":"Get weather for a city",
      "parameters":{
        "type":"object",
        "properties":{"city":{"type":"string"}},
        "required":["city"]
      }
    }],
    "tool_choice":"auto",
    "max_output_tokens":500,
    "stream":true
  }'

---

ERROR:    Exception in ASGI application
Traceback (most recent call last):
  File ".../starlette/responses.py", line 253, in stream_response
    async for chunk in self.body_iterator:
  File ".../vllm/entrypoints/openai/responses/api_router.py", line 38, in _convert_stream_to_sse_events
    async for event in generator:
  File ".../vllm/entrypoints/openai/responses/serving.py", line 1997, in responses_stream_generator
    async for event_data in processor(
  File ".../vllm/entrypoints/openai/responses/serving.py", line 1403, in _process_simple_streaming_events
    delta_message = tool_parser.extract_tool_calls_streaming(
  File ".../vllm/tool_parsers/glm4_moe_tool_parser.py", line 329, in extract_tool_calls_streaming
    is_string = self._is_string_type(
  File ".../vllm/tool_parsers/glm4_moe_tool_parser.py", line 130, in _is_string_type
    if tool.function.name != tool_name:
       ^^^^^^^^^^^^^
AttributeError: 'FunctionTool' object has no attribute 'function'

---

@staticmethod
def _is_string_type(
    tool_name: str,
    arg_name: str,
    tools: list[Tool] | None,
) -> bool:
    if tools is None:
        return False
    for tool in tools:
        # /v1/chat/completions wraps function data under `.function`;
        # /v1/responses uses a flat `FunctionTool` shape with name/parameters
        # directly on the tool itself. Support both transparently.
        func = tool.function if hasattr(tool, "function") else tool
        if func.name != tool_name:
            continue
        if func.parameters is None:
            return False
        arg_type = (
            func.parameters.get("properties", {})
            .get(arg_name, {})
            .get("type", None)
        )
        return arg_type == "string"
    logger.debug("No tool named '%s'.", tool_name)
    return False