[Frontend] Add /classify endpoint (#17032)

Signed-off-by: Frieda (Jingying) Huang <jingyingfhuang@gmail.com>

vllm/entrypoints/openai/api_server.py

@@ -48,6 +48,8 @@ from vllm.entrypoints.openai.cli_args import (log_non_default_args,
 # yapf: disable
 from vllm.entrypoints.openai.protocol import (ChatCompletionRequest,
                                               ChatCompletionResponse,
+                                              ClassificationRequest,
+                                              ClassificationResponse,
                                               CompletionRequest,
                                               CompletionResponse,
                                               DetokenizeRequest,
@@ -71,6 +73,8 @@ from vllm.entrypoints.openai.protocol import (ChatCompletionRequest,
                                               UnloadLoRAAdapterRequest)
 # yapf: enable
 from vllm.entrypoints.openai.serving_chat import OpenAIServingChat
+from vllm.entrypoints.openai.serving_classification import (
+    ServingClassification)
 from vllm.entrypoints.openai.serving_completion import OpenAIServingCompletion
 from vllm.entrypoints.openai.serving_embedding import OpenAIServingEmbedding
 from vllm.entrypoints.openai.serving_engine import OpenAIServing
@@ -373,6 +377,10 @@ def score(request: Request) -> Optional[ServingScores]:
     return request.app.state.openai_serving_scores
 
 
+def classify(request: Request) -> Optional[ServingClassification]:
+    return request.app.state.openai_serving_classification
+
+
 def rerank(request: Request) -> Optional[ServingScores]:
     return request.app.state.openai_serving_scores
 
@@ -405,6 +413,7 @@ async def get_server_load_metrics(request: Request):
     # - /v1/audio/transcriptions
     # - /v1/embeddings
     # - /pooling
+    # - /classify
     # - /score
     # - /v1/score
     # - /rerank
@@ -572,6 +581,27 @@ async def create_pooling(request: PoolingRequest, raw_request: Request):
     assert_never(generator)
 
 
+@router.post("/classify", dependencies=[Depends(validate_json_request)])
+@with_cancellation
+@load_aware_call
+async def create_classify(request: ClassificationRequest,
+                          raw_request: Request):
+    handler = classify(raw_request)
+    if handler is None:
+        return base(raw_request).create_error_response(
+            message="The model does not support Classification API")
+
+    generator = await handler.create_classify(request, raw_request)
+    if isinstance(generator, ErrorResponse):
+        return JSONResponse(content=generator.model_dump(),
+                            status_code=generator.code)
+
+    elif isinstance(generator, ClassificationResponse):
+        return JSONResponse(content=generator.model_dump())
+
+    assert_never(generator)
+
+
 @router.post("/score", dependencies=[Depends(validate_json_request)])
 @with_cancellation
 @load_aware_call
@@ -1001,6 +1031,12 @@ async def init_app_state(
         state.openai_serving_models,
         request_logger=request_logger) if model_config.task in (
             "score", "embed", "pooling") else None
+    state.openai_serving_classification = ServingClassification(
+        engine_client,
+        model_config,
+        state.openai_serving_models,
+        request_logger=request_logger,
+    ) if model_config.task == "classify" else None
     state.jinaai_serving_reranking = ServingScores(
         engine_client,
         model_config,