Preliminary Support for Qwen3XMLDetector (#8260)

Co-authored-by: Chayenne <zhaochen20@outlook.com>

python/sglang/srt/function_call/function_call_parser.py

@@ -14,6 +14,7 @@ from sglang.srt.function_call.kimik2_detector import KimiK2Detector
 from sglang.srt.function_call.llama32_detector import Llama32Detector
 from sglang.srt.function_call.mistral_detector import MistralDetector
 from sglang.srt.function_call.pythonic_detector import PythonicDetector
+from sglang.srt.function_call.qwen3_detector import Qwen3XMLDetector
 from sglang.srt.function_call.qwen25_detector import Qwen25Detector
 
 logger = logging.getLogger(__name__)
@@ -35,6 +36,7 @@ class FunctionCallParser:
         "deepseekv3": DeepSeekV3Detector,
         "pythonic": PythonicDetector,
         "kimi_k2": KimiK2Detector,
+        "qwen3": Qwen3XMLDetector,
     }
 
     def __init__(self, tools: List[Tool], tool_call_parser: str):

python/sglang/srt/function_call/qwen3_detector.py

@@ -0,0 +1,150 @@
+import ast
+import html
+import json
+import logging
+import re
+from typing import Any, Dict, List, Tuple
+
+from sglang.srt.entrypoints.openai.protocol import Tool
+from sglang.srt.function_call.base_format_detector import BaseFormatDetector
+from sglang.srt.function_call.core_types import (
+    StreamingParseResult,
+    StructureInfo,
+    ToolCallItem,
+    _GetInfoFunc,
+)
+from sglang.srt.function_call.ebnf_composer import EBNFComposer
+
+logger = logging.getLogger(__name__)
+
+
+def _safe_val(raw: str) -> Any:
+    raw = html.unescape(raw.strip())
+    try:
+        return json.loads(raw)
+    except Exception:
+        try:
+            return ast.literal_eval(raw)
+        except Exception:
+            return raw
+
+
+class Qwen3XMLDetector(BaseFormatDetector):
+    """
+    Detector for Qwen 3 models.
+    Assumes function call format:
+        <tool_call>
+        <function=execute_bash>
+        <parameter=command>
+        pwd && ls
+        </parameter>
+        </function>
+        </tool_call>
+    """
+
+    def __init__(self):
+        super().__init__()
+        self.tool_call_start_token: str = "<tool_call>"
+        self.tool_call_end_token: str = "</tool_call>"
+        self.tool_call_prefix: str = "<function="
+        self.tool_call_regex = re.compile(
+            r"<tool_call>(.*?)</tool_call>|<tool_call>(.*?)$", re.DOTALL
+        )
+        self.tool_call_function_regex = re.compile(
+            r"<function=(.*?)</function>|<function=(.*)$", re.DOTALL
+        )
+        self.tool_call_parameter_regex = re.compile(
+            r"<parameter=(.*?)</parameter>|<parameter=(.*?)$", re.DOTALL
+        )
+        self._buf: str = ""
+
+    def has_tool_call(self, text: str) -> bool:
+        return self.tool_call_start_token in text
+
+    def detect_and_parse(self, text: str, tools: List[Tool]) -> StreamingParseResult:
+        normal, calls = self._extract(text, tools)
+        return StreamingParseResult(normal_text=normal, calls=calls)
+
+    def parse_streaming_increment(
+        self, new_text: str, tools: List[Tool]
+    ) -> StreamingParseResult:
+        self._buf += new_text
+        normal = ""
+        calls: List[ToolCallItem] = []
+        while True:
+            if self.tool_call_start_token not in self._buf:
+                normal += self._buf
+                self._buf = ""
+                break
+            s = self._buf.find(self.tool_call_start_token)
+            if s > 0:
+                normal += self._buf[:s]
+                self._buf = self._buf[s:]
+            e = self._buf.find(self.tool_call_end_token)
+            if e == -1:
+                break
+            block = self._buf[: e + len(self.tool_call_end_token)]
+            self._buf = self._buf[e + len(self.tool_call_end_token) :]
+            calls.extend(self._parse_block(block, tools))
+        return StreamingParseResult(normal_text=normal, calls=calls)
+
+    def _extract(self, text: str, tools: List[Tool]) -> Tuple[str, List[ToolCallItem]]:
+        normal_parts: List[str] = []
+        calls: List[ToolCallItem] = []
+        cursor = 0
+        while True:
+            s = text.find(self.tool_call_start_token, cursor)
+            if s == -1:
+                normal_parts.append(text[cursor:])
+                break
+            normal_parts.append(text[cursor:s])
+            e = text.find(self.tool_call_end_token, s)
+            if e == -1:
+                normal_parts.append(text[s:])
+                break
+            block = text[s : e + len(self.tool_call_end_token)]
+            cursor = e + len(self.tool_call_end_token)
+            calls.extend(self._parse_block(block, tools))
+        return "".join(normal_parts), calls
+
+    def _parse_block(self, block: str, tools: List[Tool]) -> List[ToolCallItem]:
+        res: List[ToolCallItem] = []
+        for m in self.tool_call_function_regex.findall(block):
+            txt = m[0] if m[0] else m[1]
+            if ">" not in txt:
+                continue
+            idx = txt.index(">")
+            fname = txt[:idx].strip()
+            body = txt[idx + 1 :]
+            params: Dict[str, Any] = {}
+            for pm in self.tool_call_parameter_regex.findall(body):
+                ptxt = pm[0] if pm[0] else pm[1]
+                if ">" not in ptxt:
+                    continue
+                pidx = ptxt.index(">")
+                pname = ptxt[:pidx].strip()
+                pval = ptxt[pidx + 1 :].lstrip("\n").rstrip("\n")
+                params[pname] = _safe_val(pval)
+            raw = {"name": fname, "arguments": params}
+            try:
+                res.extend(self.parse_base_json(raw, tools))
+            except Exception:
+                logger.warning("invalid tool call for %s dropped", fname)
+        return res
+
+    def structure_info(self) -> _GetInfoFunc:
+        return lambda n: StructureInfo(
+            begin=f"{self.tool_call_start_token}\n<function={n}>",
+            end=f"</function>\n{self.tool_call_end_token}",
+            trigger=self.tool_call_start_token,
+        )
+
+    # TODO: fake ebnf for xml + outlines backend
+    def build_ebnf(self, tools: List[Tool]):
+        return EBNFComposer.build_ebnf(
+            tools,
+            individual_call_start_token=self.tool_call_start_token.replace("\n", "\\n"),
+            individual_call_end_token=self.tool_call_end_token.replace("\n", "\\n"),
+            tool_call_separator="\\n",
+            function_format="json",
+        )

python/sglang/srt/server_args.py

@@ -1099,6 +1099,7 @@ class ServerArgs:
                 "deepseekv3",
                 "pythonic",
                 "kimi_k2",
+                "qwen3",
             ],
             default=ServerArgs.tool_call_parser,
             help="Specify the parser for handling tool-call interactions. Options include: 'qwen25', 'mistral', 'llama3', 'deepseekv3', 'pythonic', and 'kimi_k2'.",