feat: Add model version tracking with API endpoints and response metadata (#8795)

python/sglang/srt/entrypoints/http_server.py

@@ -88,6 +88,7 @@ from sglang.srt.managers.io_struct import (
     UpdateWeightFromDiskReqInput,
     UpdateWeightsFromDistributedReqInput,
     UpdateWeightsFromTensorReqInput,
+    UpdateWeightVersionReqInput,
     VertexGenerateReqInput,
 )
 from sglang.srt.managers.template_manager import TemplateManager
@@ -342,10 +343,19 @@ async def get_model_info():
         "tokenizer_path": _global_state.tokenizer_manager.server_args.tokenizer_path,
         "is_generation": _global_state.tokenizer_manager.is_generation,
         "preferred_sampling_params": _global_state.tokenizer_manager.server_args.preferred_sampling_params,
+        "weight_version": _global_state.tokenizer_manager.server_args.weight_version,
     }
     return result
 
 
+@app.get("/get_weight_version")
+async def get_weight_version():
+    """Get the current weight version."""
+    return {
+        "weight_version": _global_state.tokenizer_manager.server_args.weight_version
+    }
+
+
 @app.get("/get_server_info")
 async def get_server_info():
     # Returns interna states per DP.
@@ -537,6 +547,12 @@ async def update_weights_from_disk(obj: UpdateWeightFromDiskReqInput, request: R
     success, message, num_paused_requests = (
         await _global_state.tokenizer_manager.update_weights_from_disk(obj, request)
     )
+
+    # Update weight version if provided and weights update was successful
+    if success and obj.weight_version is not None:
+        _update_weight_version_if_provided(obj.weight_version)
+        message += f" Weight version updated to {obj.weight_version}."
+
     content = {
         "success": success,
         "message": message,
@@ -583,6 +599,12 @@ async def update_weights_from_tensor(
     success, message = await _global_state.tokenizer_manager.update_weights_from_tensor(
         obj, request
     )
+
+    # Update weight version if provided and weights update was successful
+    if success and obj.weight_version is not None:
+        _update_weight_version_if_provided(obj.weight_version)
+        message += f" Weight version updated to {obj.weight_version}."
+
     content = {"success": success, "message": message}
     return ORJSONResponse(
         content, status_code=200 if success else HTTPStatus.BAD_REQUEST
@@ -599,6 +621,12 @@ async def update_weights_from_distributed(
             obj, request
         )
     )
+
+    # Update weight version if provided and weights update was successful
+    if success and obj.weight_version is not None:
+        _update_weight_version_if_provided(obj.weight_version)
+        message += f" Weight version updated to {obj.weight_version}."
+
     content = {"success": success, "message": message}
     if success:
         return ORJSONResponse(content, status_code=200)
@@ -606,6 +634,36 @@ async def update_weights_from_distributed(
         return ORJSONResponse(content, status_code=HTTPStatus.BAD_REQUEST)
 
 
+@app.post("/update_weight_version")
+async def update_weight_version(obj: UpdateWeightVersionReqInput, request: Request):
+    """Update the weight version. This operation requires no active requests."""
+    if obj.abort_all_requests:
+        _global_state.tokenizer_manager.abort_request(abort_all=True)
+
+    # Use a simple approach without the complex lock mechanism for now
+    # since weight_version update is a simple operation that doesn't affect model weights
+    try:
+        # Update the weight version in server args (the single source of truth)
+        _global_state.tokenizer_manager.server_args.weight_version = obj.new_version
+
+        return ORJSONResponse(
+            {
+                "success": True,
+                "message": f"Weight version updated to {obj.new_version}",
+                "new_version": obj.new_version,
+            },
+            status_code=HTTPStatus.OK,
+        )
+    except Exception as e:
+        return ORJSONResponse(
+            {
+                "success": False,
+                "message": f"Failed to update weight version: {str(e)}",
+            },
+            status_code=HTTPStatus.BAD_REQUEST,
+        )
+
+
 @app.api_route("/get_weights_by_name", methods=["GET", "POST"])
 async def get_weights_by_name(obj: GetWeightsByNameReqInput, request: Request):
     """Get model parameter by name."""
@@ -966,6 +1024,12 @@ async def vertex_generate(vertex_req: VertexGenerateReqInput, raw_request: Reque
     return ORJSONResponse({"predictions": ret})
 
 
+def _update_weight_version_if_provided(weight_version: Optional[str]) -> None:
+    """Update weight version if provided."""
+    if weight_version is not None:
+        _global_state.tokenizer_manager.server_args.weight_version = weight_version
+
+
 def _create_error_response(e):
     return ORJSONResponse(
         {"error": {"message": str(e)}}, status_code=HTTPStatus.BAD_REQUEST

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

@@ -240,6 +240,7 @@ class CompletionResponse(BaseModel):
     model: str
     choices: List[CompletionResponseChoice]
     usage: UsageInfo
+    metadata: Optional[Dict[str, Any]] = None
 
 
 class CompletionResponseStreamChoice(BaseModel):
@@ -517,6 +518,7 @@ class ChatCompletionResponse(BaseModel):
     model: str
     choices: List[ChatCompletionResponseChoice]
     usage: UsageInfo
+    metadata: Optional[Dict[str, Any]] = None
 
 
 class DeltaMessage(BaseModel):

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

@@ -723,6 +723,7 @@ class OpenAIServingChat(OpenAIServingBase):
             model=request.model,
             choices=choices,
             usage=usage,
+            metadata={"weight_version": ret[0]["meta_info"]["weight_version"]},
         )
 
     def _process_logprobs_tokens(

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

@@ -373,6 +373,7 @@ class OpenAIServingCompletion(OpenAIServingBase):
             created=created,
             choices=choices,
             usage=usage,
+            metadata={"weight_version": ret[0]["meta_info"]["weight_version"]},
         )
 
     def _get_echo_text(self, request: CompletionRequest, index: int) -> str: