Add 'anyOf' schema support for qwen3_coder tool call parser (#30832)

Co-authored-by: Xinyuan Tong <115166877+JustinTong0323@users.noreply.github.com>
Co-authored-by: Liangsheng Yin <hnyls2002@gmail.com>
Co-authored-by: Alex Nails <alex.nails@radixark.ai>

python/sglang/srt/function_call/qwen3_coder_detector.py

@@ -11,6 +11,7 @@ from sglang.srt.function_call.core_types import (
     ToolCallItem,
     _GetInfoFunc,
 )
+from sglang.srt.function_call.utils import infer_type_from_json_schema
 
 logger = logging.getLogger(__name__)
 
@@ -86,6 +87,13 @@ class Qwen3CoderDetector(BaseFormatDetector):
         logger.warning(f"Tool '{func_name}' is not defined in the tools list.")
         return {}
 
+    def _get_param_type(self, param_schema: Any) -> str:
+        """Infer the parser conversion type from a JSON schema parameter."""
+        inferred_type = infer_type_from_json_schema(param_schema)
+        if inferred_type is None:
+            return "string"
+        return str(inferred_type).strip().lower()
+
     def _convert_param_value(
         self, param_value: str, param_name: str, param_config: dict, func_name: str
     ) -> Any:
@@ -102,13 +110,7 @@ class Qwen3CoderDetector(BaseFormatDetector):
                 )
             return param_value
 
-        if (
-            isinstance(param_config[param_name], dict)
-            and "type" in param_config[param_name]
-        ):
-            param_type = str(param_config[param_name]["type"]).strip().lower()
-        else:
-            param_type = "string"
+        param_type = self._get_param_type(param_config[param_name])
         if param_type in ["string", "str", "text", "varchar", "char", "enum"]:
             return param_value
         elif (

python/sglang/srt/function_call/utils.py

@@ -320,6 +320,9 @@ def infer_type_from_json_schema(schema: Dict[str, Any]) -> Optional[str]:
                 # If all types are the same, return unified type
                 if len(set(types)) == 1:
                     return types[0]
+                # If it's an optional type, return original type.
+                if len(set(types)) == 2 and "null" in types:
+                    return [t for t in types if t != "null"][0]
                 # When types differ, prioritize string (safest)
                 if "string" in types:
                     return "string"