[Frontend] Add /v1/audio/transcriptions OpenAI API endpoint (#12909)

vllm/entrypoints/openai/api_server.py

@@ -16,10 +16,10 @@ from argparse import Namespace
 from contextlib import asynccontextmanager
 from functools import partial
 from http import HTTPStatus
-from typing import AsyncIterator, Dict, Optional, Set, Tuple, Union
+from typing import Annotated, AsyncIterator, Dict, Optional, Set, Tuple, Union
 
 import uvloop
-from fastapi import APIRouter, Depends, FastAPI, HTTPException, Request
+from fastapi import APIRouter, Depends, FastAPI, Form, HTTPException, Request
 from fastapi.exceptions import RequestValidationError
 from fastapi.middleware.cors import CORSMiddleware
 from fastapi.responses import JSONResponse, Response, StreamingResponse
@@ -61,6 +61,8 @@ from vllm.entrypoints.openai.protocol import (ChatCompletionRequest,
                                               ScoreRequest, ScoreResponse,
                                               TokenizeRequest,
                                               TokenizeResponse,
+                                              TranscriptionRequest,
+                                              TranscriptionResponse,
                                               UnloadLoraAdapterRequest)
 from vllm.entrypoints.openai.reasoning_parsers import ReasoningParserManager
 # yapf: enable
@@ -75,6 +77,8 @@ from vllm.entrypoints.openai.serving_rerank import JinaAIServingRerank
 from vllm.entrypoints.openai.serving_score import OpenAIServingScores
 from vllm.entrypoints.openai.serving_tokenization import (
     OpenAIServingTokenization)
+from vllm.entrypoints.openai.serving_transcription import (
+    OpenAIServingTranscription)
 from vllm.entrypoints.openai.tool_parsers import ToolParserManager
 from vllm.entrypoints.utils import with_cancellation
 from vllm.logger import init_logger
@@ -327,6 +331,10 @@ def tokenization(request: Request) -> OpenAIServingTokenization:
     return request.app.state.openai_serving_tokenization
 
 
+def transcription(request: Request) -> OpenAIServingTranscription:
+    return request.app.state.openai_serving_transcription
+
+
 def engine_client(request: Request) -> EngineClient:
     return request.app.state.engine_client
 
@@ -520,6 +528,31 @@ async def create_score_v1(request: ScoreRequest, raw_request: Request):
     return await create_score(request, raw_request)
 
 
+@router.post("/v1/audio/transcriptions")
+@with_cancellation
+async def create_transcriptions(request: Annotated[TranscriptionRequest,
+                                                   Form()],
+                                raw_request: Request):
+
+    handler = transcription(raw_request)
+    if handler is None:
+        return base(raw_request).create_error_response(
+            message="The model does not support Transcriptions API")
+
+    audio_data = await request.file.read()
+    generator = await handler.create_transcription(audio_data, request,
+                                                   raw_request)
+
+    if isinstance(generator, ErrorResponse):
+        return JSONResponse(content=generator.model_dump(),
+                            status_code=generator.code)
+
+    elif isinstance(generator, TranscriptionResponse):
+        return JSONResponse(content=generator.model_dump())
+
+    return StreamingResponse(content=generator, media_type="text/event-stream")
+
+
 @router.post("/rerank", dependencies=[Depends(validate_json_request)])
 @with_cancellation
 async def do_rerank(request: RerankRequest, raw_request: Request):
@@ -832,6 +865,12 @@ async def init_app_state(
         chat_template=resolved_chat_template,
         chat_template_content_format=args.chat_template_content_format,
     )
+    state.openai_serving_transcription = OpenAIServingTranscription(
+        engine_client,
+        model_config,
+        state.openai_serving_models,
+        request_logger=request_logger,
+    ) if model_config.runner_type == "transcription" else None
     state.task = model_config.task