Qwen3 parser for tool calls and reasoning.
Qwen3 XML tool call format::
<tool_call>
<function=func_name>
<parameter=key>value</parameter>
</function>
</tool_call>
The argument body consists of <parameter=NAME>VALUE</parameter> tags. The _qwen3_arg_converter parses these into a JSON object.
Classes:
-
Qwen3Parser – Qwen3 parser: <think>/</think> reasoning +
Qwen3Parser
Bases: ParserEngine
Qwen3 parser: <think>/</think> reasoning + <tool_call> XML tool calls in a single engine.
<tool_call> as implicit reasoning end- Unpaired
<tool_call> token ID detection for is_reasoning_end
Source code in vllm/parser/qwen3.py
| class Qwen3Parser(ParserEngine):
"""Qwen3 parser: ``<think>``/``</think>`` reasoning +
``<tool_call>`` XML tool calls in a single engine.
- ``<tool_call>`` as implicit reasoning end
- Unpaired ``<tool_call>`` token ID detection for ``is_reasoning_end``
"""
def __init__(
self,
tokenizer: TokenizerLike,
tools: list[Tool] | None = None,
**kwargs,
) -> None:
chat_kwargs = kwargs.get("chat_template_kwargs", {}) or {}
self.thinking_enabled = chat_kwargs.get("enable_thinking", True)
kwargs.setdefault(
"parser_engine_config",
qwen3_config(thinking=self.thinking_enabled),
)
super().__init__(
tokenizer,
tools,
**kwargs,
)
vocab = self.vocab
self._tool_call_token_id: int | None = vocab.get("<tool_call>")
self._tool_call_end_token_id: int | None = vocab.get("</tool_call>")
def extract_reasoning(
self,
model_output: str,
request: ChatCompletionRequest | ResponsesRequest,
) -> tuple[str | None, str | None]:
if not self.thinking_enabled:
return None, model_output
return super().extract_reasoning(model_output, request)
def is_reasoning_end(self, input_ids: list[int]) -> bool:
if super().is_reasoning_end(input_ids):
return True
tool_call_id = self._tool_call_token_id
tool_call_end_id = self._tool_call_end_token_id
if tool_call_id is not None:
for i in range(len(input_ids) - 1, -1, -1):
if input_ids[i] == tool_call_id:
if tool_call_end_id is not None and any(
input_ids[j] == tool_call_end_id
for j in range(i + 1, len(input_ids))
):
continue
return True
return False
|