accomendate json schema in the "schema" field, not in "json_schema" field of response_format (#9786)

python/sglang/srt/entrypoints/openai/protocol.py

@@ -460,6 +460,38 @@ class ChatCompletionRequest(BaseModel):
                 values["tool_choice"] = "auto"
         return values
 
+    @model_validator(mode="before")
+    @classmethod
+    def set_json_schema(cls, values):
+        response_format = values.get("response_format")
+        if not response_format:
+            return values
+
+        if response_format.get("type") != "json_schema":
+            return values
+
+        schema = response_format.pop("schema", None)
+        json_schema = response_format.get("json_schema")
+
+        if json_schema:
+            return values
+
+        if schema:
+            name_ = schema.get("title", "Schema")
+            strict_ = False
+            if "properties" in schema and "strict" in schema["properties"]:
+                item = schema["properties"].pop("strict", None)
+                if item and item.get("default", False):
+                    strict_ = True
+
+            response_format["json_schema"] = {
+                "name": name_,
+                "schema": schema,
+                "strict": strict_,
+            }
+
+        return values
+
     # Extra parameters for SRT backend only and will be ignored by OpenAI models.
     top_k: int = -1
     min_p: float = 0.0