[FEAT] JSON constrained support (#1125)

Co-authored-by: Yineng Zhang <me@zhyncs.com>

python/sglang/srt/openai_api/adapter.py

@@ -434,6 +434,7 @@ def v1_generate_request(all_requests: List[CompletionRequest]):
                 "frequency_penalty": request.frequency_penalty,
                 "repetition_penalty": request.repetition_penalty,
                 "regex": request.regex,
+                "json_schema": request.json_schema,
                 "n": request.n,
                 "ignore_eos": request.ignore_eos,
             }
@@ -802,6 +803,7 @@ def v1_chat_generate_request(
                 "frequency_penalty": request.frequency_penalty,
                 "repetition_penalty": request.repetition_penalty,
                 "regex": request.regex,
+                "json_schema": request.json_schema,
                 "n": request.n,
             }
         )

python/sglang/srt/openai_api/protocol.py

@@ -161,6 +161,7 @@ class CompletionRequest(BaseModel):
 
     # Extra parameters for SRT backend only and will be ignored by OpenAI models.
     regex: Optional[str] = None
+    json_schema: Optional[str] = None
     ignore_eos: Optional[bool] = False
     min_tokens: Optional[int] = 0
     repetition_penalty: Optional[float] = 1.0
@@ -262,6 +263,7 @@ 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)