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vllm.entrypoints.api_server

NOTE: This API server is used only for demonstrating usage of AsyncEngine and simple performance benchmarks. It is not intended for production use. For production use, we recommend using our OpenAI compatible server. We are also not going to accept PRs modifying this file, please change vllm/entrypoints/openai/api_server.py instead.

app module-attribute 

app = FastAPI()

args module-attribute 

args = parse_args()

engine module-attribute 

engine = None

logger module-attribute 

logger = init_logger('vllm.entrypoints.api_server')

parser module-attribute 

parser = FlexibleArgumentParser()

_generate async 

_generate(
    request_dict: dict, raw_request: Request
) -> Response
Source code in vllm/entrypoints/api_server.py 
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@with_cancellation
async def _generate(request_dict: dict, raw_request: Request) -> Response:
    prompt = request_dict.pop("prompt")
    stream = request_dict.pop("stream", False)
    sampling_params = SamplingParams(**request_dict)
    request_id = random_uuid()

    assert engine is not None
    results_generator = engine.generate(prompt, sampling_params, request_id)

    # Streaming case
    async def stream_results() -> AsyncGenerator[bytes, None]:
        async for request_output in results_generator:
            prompt = request_output.prompt
            assert prompt is not None
            text_outputs = [prompt + output.text for output in request_output.outputs]
            ret = {"text": text_outputs}
            yield (json.dumps(ret) + "\n").encode("utf-8")

    if stream:
        return StreamingResponse(stream_results())

    # Non-streaming case
    final_output = None
    try:
        async for request_output in results_generator:
            final_output = request_output
    except asyncio.CancelledError:
        return Response(status_code=499)

    assert final_output is not None
    prompt = final_output.prompt
    assert prompt is not None
    text_outputs = [prompt + output.text for output in final_output.outputs]
    ret = {"text": text_outputs}
    return JSONResponse(ret)

build_app 

build_app(args: Namespace) -> FastAPI
Source code in vllm/entrypoints/api_server.py 
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def build_app(args: Namespace) -> FastAPI:
    global app

    app.root_path = args.root_path
    return app

generate async 

generate(request: Request) -> Response

Generate completion for the request.

The request should be a JSON object with the following fields: - prompt: the prompt to use for the generation. - stream: whether to stream the results or not. - other fields: the sampling parameters (See SamplingParams for details).

Source code in vllm/entrypoints/api_server.py 
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@app.post("/generate")
async def generate(request: Request) -> Response:
    """Generate completion for the request.

    The request should be a JSON object with the following fields:
    - prompt: the prompt to use for the generation.
    - stream: whether to stream the results or not.
    - other fields: the sampling parameters (See `SamplingParams` for details).
    """
    request_dict = await request.json()
    return await _generate(request_dict, raw_request=request)

health async 

health() -> Response

Health check.

Source code in vllm/entrypoints/api_server.py 
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@app.get("/health")
async def health() -> Response:
    """Health check."""
    return Response(status_code=200)

init_app async 

init_app(
    args: Namespace,
    llm_engine: AsyncLLMEngine | None = None,
) -> FastAPI
Source code in vllm/entrypoints/api_server.py 
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async def init_app(
    args: Namespace,
    llm_engine: AsyncLLMEngine | None = None,
) -> FastAPI:
    app = build_app(args)

    global engine

    engine_args = AsyncEngineArgs.from_cli_args(args)
    engine = (
        llm_engine
        if llm_engine is not None
        else AsyncLLMEngine.from_engine_args(
            engine_args, usage_context=UsageContext.API_SERVER
        )
    )
    app.state.engine_client = engine
    return app

run_server async 

run_server(
    args: Namespace,
    llm_engine: AsyncLLMEngine | None = None,
    **uvicorn_kwargs: Any,
) -> None
Source code in vllm/entrypoints/api_server.py 
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async def run_server(
    args: Namespace, llm_engine: AsyncLLMEngine | None = None, **uvicorn_kwargs: Any
) -> None:
    logger.info("vLLM API server version %s", VLLM_VERSION)
    logger.info("args: %s", args)

    set_ulimit()

    app = await init_app(args, llm_engine)
    assert engine is not None

    shutdown_task = await serve_http(
        app,
        sock=None,
        enable_ssl_refresh=args.enable_ssl_refresh,
        host=args.host,
        port=args.port,
        log_level=args.log_level,
        timeout_keep_alive=envs.VLLM_HTTP_TIMEOUT_KEEP_ALIVE,
        ssl_keyfile=args.ssl_keyfile,
        ssl_certfile=args.ssl_certfile,
        ssl_ca_certs=args.ssl_ca_certs,
        ssl_cert_reqs=args.ssl_cert_reqs,
        **uvicorn_kwargs,
    )

    await shutdown_task