Support OpenAI API json_schema response format (#1363)

python/sglang/srt/openai_api/protocol.py

@@ -82,6 +82,14 @@ class StreamOptions(BaseModel):
     include_usage: Optional[bool] = False
 
 
+class JsonSchemaResponseFormat(BaseModel):
+    name: str
+    description: Optional[str] = None
+    # use alias to workaround pydantic conflict
+    schema_: Optional[Dict[str, object]] = Field(alias="schema", default=None)
+    strict: Optional[bool] = False
+
+
 class FileRequest(BaseModel):
     # https://platform.openai.com/docs/api-reference/files/create
     file: bytes  # The File object (not file name) to be uploaded
@@ -237,8 +245,8 @@ ChatCompletionMessageParam = Union[
 
 
 class ResponseFormat(BaseModel):
-    # type must be "json_object" or "text"
-    type: Literal["text", "json_object"]
+    type: Literal["text", "json_object", "json_schema"]
+    json_schema: Optional[JsonSchemaResponseFormat] = None
 
 
 class ChatCompletionRequest(BaseModel):
@@ -264,7 +272,6 @@ class ChatCompletionRequest(BaseModel):
 
     # Extra parameters for SRT backend only and will be ignored by OpenAI models.
     regex: Optional[str] = None
-    json_schema: Optional[str] = None
     min_tokens: Optional[int] = 0
     repetition_penalty: Optional[float] = 1.0
     stop_token_ids: Optional[List[int]] = Field(default_factory=list)