"""A server that provides OpenAI-compatible RESTful APIs. It supports: - Chat Completions. (Reference: https://platform.openai.com/docs/api-reference/chat) - Completions. (Reference: https://platform.openai.com/docs/api-reference/completions) - Embeddings. (Reference: https://platform.openai.com/docs/api-reference/embeddings) Usage: python3 -m fastchat.serve.openai_api_server """ import asyncio import argparse import asyncio import json import logging import os from typing import Generator, Optional, Union, Dict, List, Any import fastapi from fastapi import Depends, HTTPException from fastapi.middleware.cors import CORSMiddleware from fastapi.responses import StreamingResponse, JSONResponse from fastapi.security.http import HTTPAuthorizationCredentials, HTTPBearer import httpx from pydantic import BaseSettings import shortuuid import tiktoken import uvicorn from fastchat.constants import ( WORKER_API_TIMEOUT, WORKER_API_EMBEDDING_BATCH_SIZE, ErrorCode, ) from fastchat.conversation import Conversation, SeparatorStyle from fastchat.model.model_adapter import get_conversation_template from fastapi.exceptions import RequestValidationError from fastchat.protocol.openai_api_protocol import ( ChatCompletionRequest, ChatCompletionResponse, ChatCompletionResponseStreamChoice, ChatCompletionStreamResponse, ChatMessage, ChatCompletionResponseChoice, CompletionRequest, CompletionResponse, CompletionResponseChoice, DeltaMessage, CompletionResponseStreamChoice, CompletionStreamResponse, EmbeddingsRequest, EmbeddingsResponse, ErrorResponse, ModelCard, ModelList, ModelPermission, UsageInfo, ) from fastchat.protocol.api_protocol import ( APIChatCompletionRequest, APITokenCheckRequest, APITokenCheckResponse, APITokenCheckResponseItem, ) logger = logging.getLogger(__name__) conv_template_map = {} class AppSettings(BaseSettings): # The address of the model controller. controller_address: str = "http://localhost:21001" api_keys: List[str] = None app_settings = AppSettings() app = fastapi.FastAPI() headers = {"User-Agent": "FastChat API Server"} get_bearer_token = HTTPBearer(auto_error=False) async def check_api_key( auth: Optional[HTTPAuthorizationCredentials] = Depends(get_bearer_token), ) -> str: if app_settings.api_keys: if auth is None or (token := auth.credentials) not in app_settings.api_keys: raise HTTPException( status_code=401, detail={ "error": { "message": "", "type": "invalid_request_error", "param": None, "code": "invalid_api_key", } }, ) return token else: # api_keys not set; allow all return None def create_error_response(code: int, message: str) -> JSONResponse: return JSONResponse( ErrorResponse(message=message, code=code).dict(), status_code=400 ) @app.exception_handler(RequestValidationError) async def validation_exception_handler(request, exc): return create_error_response(ErrorCode.VALIDATION_TYPE_ERROR, str(exc)) async def check_model(request) -> Optional[JSONResponse]: controller_address = app_settings.controller_address ret = None async with httpx.AsyncClient() as client: try: _worker_addr = await get_worker_address(request.model, client) except: models_ret = await client.post(controller_address + "/list_models") models = models_ret.json()["models"] ret = create_error_response( ErrorCode.INVALID_MODEL, f"Only {'&&'.join(models)} allowed now, your model {request.model}", ) return ret async def check_length(request, prompt, max_tokens): async with httpx.AsyncClient() as client: worker_addr = await get_worker_address(request.model, client) response = await client.post( worker_addr + "/model_details", headers=headers, json={"model": request.model}, timeout=WORKER_API_TIMEOUT, ) context_len = response.json()["context_length"] response = await client.post( worker_addr + "/count_token", headers=headers, json={"model": request.model, "prompt": prompt}, timeout=WORKER_API_TIMEOUT, ) token_num = response.json()["count"] if token_num + max_tokens > context_len: return create_error_response( ErrorCode.CONTEXT_OVERFLOW, f"This model's maximum context length is {context_len} tokens. " f"However, you requested {max_tokens + token_num} tokens " f"({token_num} in the messages, " f"{max_tokens} in the completion). " f"Please reduce the length of the messages or completion.", ) else: return None def check_requests(request) -> Optional[JSONResponse]: # Check all params if request.max_tokens is not None and request.max_tokens <= 0: return create_error_response( ErrorCode.PARAM_OUT_OF_RANGE, f"{request.max_tokens} is less than the minimum of 1 - 'max_tokens'", ) if request.n is not None and request.n <= 0: return create_error_response( ErrorCode.PARAM_OUT_OF_RANGE, f"{request.n} is less than the minimum of 1 - 'n'", ) if request.temperature is not None and request.temperature < 0: return create_error_response( ErrorCode.PARAM_OUT_OF_RANGE, f"{request.temperature} is less than the minimum of 0 - 'temperature'", ) if request.temperature is not None and request.temperature > 2: return create_error_response( ErrorCode.PARAM_OUT_OF_RANGE, f"{request.temperature} is greater than the maximum of 2 - 'temperature'", ) if request.top_p is not None and request.top_p < 0: return create_error_response( ErrorCode.PARAM_OUT_OF_RANGE, f"{request.top_p} is less than the minimum of 0 - 'top_p'", ) if request.top_p is not None and request.top_p > 1: return create_error_response( ErrorCode.PARAM_OUT_OF_RANGE, f"{request.top_p} is greater than the maximum of 1 - 'temperature'", ) if request.stop is not None and ( not isinstance(request.stop, str) and not isinstance(request.stop, list) ): return create_error_response( ErrorCode.PARAM_OUT_OF_RANGE, f"{request.stop} is not valid under any of the given schemas - 'stop'", ) return None def process_input(model_name, inp): if isinstance(inp, str): inp = [inp] elif isinstance(inp, list): if isinstance(inp[0], int): decoding = tiktoken.model.encoding_for_model(model_name) inp = [decoding.decode(inp)] elif isinstance(inp[0], list): decoding = tiktoken.model.encoding_for_model(model_name) inp = [decoding.decode(text) for text in inp] return inp async def get_gen_params( model_name: str, messages: Union[str, List[Dict[str, str]]], *, temperature: float, top_p: float, max_tokens: Optional[int], echo: Optional[bool], stream: Optional[bool], stop: Optional[Union[str, List[str]]], ) -> Dict[str, Any]: conv = await get_conv(model_name) conv = Conversation( name=conv["name"], system=conv["system"], roles=conv["roles"], messages=list(conv["messages"]), # prevent in-place modification offset=conv["offset"], sep_style=SeparatorStyle(conv["sep_style"]), sep=conv["sep"], sep2=conv["sep2"], stop_str=conv["stop_str"], stop_token_ids=conv["stop_token_ids"], ) if isinstance(messages, str): prompt = messages else: for message in messages: msg_role = message["role"] if msg_role == "system": conv.system = message["content"] elif msg_role == "user": conv.append_message(conv.roles[0], message["content"]) elif msg_role == "assistant": conv.append_message(conv.roles[1], message["content"]) else: raise ValueError(f"Unknown role: {msg_role}") # Add a blank message for the assistant. conv.append_message(conv.roles[1], None) prompt = conv.get_prompt() if max_tokens is None: max_tokens = 512 gen_params = { "model": model_name, "prompt": prompt, "temperature": temperature, "top_p": top_p, "max_new_tokens": max_tokens, "echo": echo, "stream": stream, } if not stop: gen_params.update( {"stop": conv.stop_str, "stop_token_ids": conv.stop_token_ids} ) else: gen_params.update({"stop": stop}) logger.debug(f"==== request ====\n{gen_params}") return gen_params async def get_worker_address(model_name: str, client: httpx.AsyncClient) -> str: """ Get worker address based on the requested model :param model_name: The worker's model name :param client: The httpx client to use :return: Worker address from the controller :raises: :class:`ValueError`: No available worker for requested model """ controller_address = app_settings.controller_address ret = await client.post( controller_address + "/get_worker_address", json={"model": model_name} ) worker_addr = ret.json()["address"] # No available worker if worker_addr == "": raise ValueError(f"No available worker for {model_name}") logger.debug(f"model_name: {model_name}, worker_addr: {worker_addr}") return worker_addr async def get_conv(model_name: str): controller_address = app_settings.controller_address async with httpx.AsyncClient() as client: worker_addr = await get_worker_address(model_name, client) conv_template = conv_template_map.get((worker_addr, model_name)) if conv_template is None: response = await client.post( worker_addr + "/worker_get_conv_template", headers=headers, json={"model": model_name}, timeout=WORKER_API_TIMEOUT, ) conv_template = response.json()["conv"] conv_template_map[(worker_addr, model_name)] = conv_template return conv_template @app.get("/v1/models", dependencies=[Depends(check_api_key)]) async def show_available_models(): controller_address = app_settings.controller_address async with httpx.AsyncClient() as client: ret = await client.post(controller_address + "/refresh_all_workers") ret = await client.post(controller_address + "/list_models") models = ret.json()["models"] models.sort() # TODO: return real model permission details model_cards = [] for m in models: model_cards.append(ModelCard(id=m, root=m, permission=[ModelPermission()])) return ModelList(data=model_cards) @app.post("/v1/chat/completions", dependencies=[Depends(check_api_key)]) async def create_chat_completion(request: ChatCompletionRequest): """Creates a completion for the chat message""" error_check_ret = await check_model(request) if error_check_ret is not None: return error_check_ret error_check_ret = check_requests(request) if error_check_ret is not None: return error_check_ret gen_params = await get_gen_params( request.model, request.messages, temperature=request.temperature, top_p=request.top_p, max_tokens=request.max_tokens, echo=False, stream=request.stream, stop=request.stop, ) error_check_ret = await check_length( request, gen_params["prompt"], gen_params["max_new_tokens"] ) if error_check_ret is not None: return error_check_ret if request.stream: generator = chat_completion_stream_generator( request.model, gen_params, request.n ) return StreamingResponse(generator, media_type="text/event-stream") choices = [] chat_completions = [] for i in range(request.n): content = asyncio.create_task(generate_completion(gen_params)) chat_completions.append(content) try: all_tasks = await asyncio.gather(*chat_completions) except Exception as e: return create_error_response(ErrorCode.INTERNAL_ERROR, str(e)) usage = UsageInfo() for i, content in enumerate(all_tasks): if content["error_code"] != 0: return create_error_response(content["error_code"], content["text"]) choices.append( ChatCompletionResponseChoice( index=i, message=ChatMessage(role="assistant", content=content["text"]), finish_reason=content.get("finish_reason", "stop"), ) ) if "usage" in content: task_usage = UsageInfo.parse_obj(content["usage"]) for usage_key, usage_value in task_usage.dict().items(): setattr(usage, usage_key, getattr(usage, usage_key) + usage_value) return ChatCompletionResponse(model=request.model, choices=choices, usage=usage) async def chat_completion_stream_generator( model_name: str, gen_params: Dict[str, Any], n: int ) -> Generator[str, Any, None]: """ Event stream format: https://developer.mozilla.org/en-US/docs/Web/API/Server-sent_events/Using_server-sent_events#event_stream_format """ id = f"chatcmpl-{shortuuid.random()}" finish_stream_events = [] for i in range(n): # First chunk with role choice_data = ChatCompletionResponseStreamChoice( index=i, delta=DeltaMessage(role="assistant"), finish_reason=None, ) chunk = ChatCompletionStreamResponse( id=id, choices=[choice_data], model=model_name ) yield f"data: {chunk.json(exclude_unset=True, ensure_ascii=False)}\n\n" previous_text = "" async for content in generate_completion_stream(gen_params): if content["error_code"] != 0: yield f"data: {json.dumps(content, ensure_ascii=False)}\n\n" yield "data: [DONE]\n\n" return decoded_unicode = content["text"].replace("\ufffd", "") delta_text = decoded_unicode[len(previous_text) :] previous_text = decoded_unicode if len(delta_text) == 0: delta_text = None choice_data = ChatCompletionResponseStreamChoice( index=i, delta=DeltaMessage(content=delta_text), finish_reason=content.get("finish_reason", None), ) chunk = ChatCompletionStreamResponse( id=id, choices=[choice_data], model=model_name ) if delta_text is None: if content.get("finish_reason", None) is not None: finish_stream_events.append(chunk) continue yield f"data: {chunk.json(exclude_unset=True, ensure_ascii=False)}\n\n" # There is not "content" field in the last delta message, so exclude_none to exclude field "content". for finish_chunk in finish_stream_events: yield f"data: {finish_chunk.json(exclude_none=True, ensure_ascii=False)}\n\n" yield "data: [DONE]\n\n" @app.post("/v1/completions", dependencies=[Depends(check_api_key)]) async def create_completion(request: CompletionRequest): error_check_ret = await check_model(request) if error_check_ret is not None: return error_check_ret error_check_ret = check_requests(request) if error_check_ret is not None: return error_check_ret request.prompt = process_input(request.model, request.prompt) for text in request.prompt: error_check_ret = await check_length(request, text, request.max_tokens) if error_check_ret is not None: return error_check_ret if request.stream: generator = generate_completion_stream_generator(request, request.n) return StreamingResponse(generator, media_type="text/event-stream") else: text_completions = [] for text in request.prompt: gen_params = await get_gen_params( request.model, text, temperature=request.temperature, top_p=request.top_p, max_tokens=request.max_tokens, echo=request.echo, stream=request.stream, stop=request.stop, ) for i in range(request.n): content = asyncio.create_task(generate_completion(gen_params)) text_completions.append(content) try: all_tasks = await asyncio.gather(*text_completions) except Exception as e: return create_error_response(ErrorCode.INTERNAL_ERROR, str(e)) choices = [] usage = UsageInfo() for i, content in enumerate(all_tasks): if content["error_code"] != 0: return create_error_response(content["error_code"], content["text"]) choices.append( CompletionResponseChoice( index=i, text=content["text"], logprobs=content.get("logprobs", None), finish_reason=content.get("finish_reason", "stop"), ) ) task_usage = UsageInfo.parse_obj(content["usage"]) for usage_key, usage_value in task_usage.dict().items(): setattr(usage, usage_key, getattr(usage, usage_key) + usage_value) return CompletionResponse( model=request.model, choices=choices, usage=UsageInfo.parse_obj(usage) ) async def generate_completion_stream_generator(request: CompletionRequest, n: int): model_name = request.model id = f"cmpl-{shortuuid.random()}" finish_stream_events = [] for text in request.prompt: for i in range(n): previous_text = "" gen_params = await get_gen_params( request.model, text, temperature=request.temperature, top_p=request.top_p, max_tokens=request.max_tokens, echo=request.echo, stream=request.stream, stop=request.stop, ) async for content in generate_completion_stream(gen_params): if content["error_code"] != 0: yield f"data: {json.dumps(content, ensure_ascii=False)}\n\n" yield "data: [DONE]\n\n" return decoded_unicode = content["text"].replace("\ufffd", "") delta_text = decoded_unicode[len(previous_text) :] previous_text = decoded_unicode # todo: index is not apparent choice_data = CompletionResponseStreamChoice( index=i, text=delta_text, logprobs=content.get("logprobs", None), finish_reason=content.get("finish_reason", None), ) chunk = CompletionStreamResponse( id=id, object="text_completion", choices=[choice_data], model=model_name, ) if len(delta_text) == 0: if content.get("finish_reason", None) is not None: finish_stream_events.append(chunk) continue yield f"data: {chunk.json(exclude_unset=True, ensure_ascii=False)}\n\n" # There is not "content" field in the last delta message, so exclude_none to exclude field "content". for finish_chunk in finish_stream_events: yield f"data: {finish_chunk.json(exclude_unset=True, ensure_ascii=False)}\n\n" yield "data: [DONE]\n\n" async def generate_completion_stream(payload: Dict[str, Any]): controller_address = app_settings.controller_address async with httpx.AsyncClient() as client: worker_addr = await get_worker_address(payload["model"], client) delimiter = b"\0" async with client.stream( "POST", worker_addr + "/worker_generate_stream", headers=headers, json=payload, timeout=WORKER_API_TIMEOUT, ) as response: # content = await response.aread() async for raw_chunk in response.aiter_raw(): for chunk in raw_chunk.split(delimiter): if not chunk: continue data = json.loads(chunk.decode()) yield data async def generate_completion(payload: Dict[str, Any]): async with httpx.AsyncClient() as client: worker_addr = await get_worker_address(payload["model"], client) response = await client.post( worker_addr + "/worker_generate", headers=headers, json=payload, timeout=WORKER_API_TIMEOUT, ) completion = response.json() return completion @app.post("/v1/embeddings", dependencies=[Depends(check_api_key)]) @app.post("/v1/engines/{model_name}/embeddings", dependencies=[Depends(check_api_key)]) async def create_embeddings(request: EmbeddingsRequest, model_name: str = None): """Creates embeddings for the text""" if request.model is None: request.model = model_name error_check_ret = await check_model(request) if error_check_ret is not None: return error_check_ret request.input = process_input(request.model, request.input) data = [] token_num = 0 batch_size = WORKER_API_EMBEDDING_BATCH_SIZE batches = [ request.input[i : min(i + batch_size, len(request.input))] for i in range(0, len(request.input), batch_size) ] for num_batch, batch in enumerate(batches): payload = { "model": request.model, "input": batch, } embedding = await get_embedding(payload) if "error_code" in embedding and embedding["error_code"] != 0: return create_error_response(embedding["error_code"], embedding["text"]) data += [ { "object": "embedding", "embedding": emb, "index": num_batch * batch_size + i, } for i, emb in enumerate(embedding["embedding"]) ] token_num += embedding["token_num"] return EmbeddingsResponse( data=data, model=request.model, usage=UsageInfo( prompt_tokens=token_num, total_tokens=token_num, completion_tokens=None, ), ).dict(exclude_none=True) async def get_embedding(payload: Dict[str, Any]): controller_address = app_settings.controller_address model_name = payload["model"] async with httpx.AsyncClient() as client: worker_addr = await get_worker_address(model_name, client) response = await client.post( worker_addr + "/worker_get_embeddings", headers=headers, json=payload, timeout=WORKER_API_TIMEOUT, ) embedding = response.json() return embedding ### GENERAL API - NOT OPENAI COMPATIBLE ### @app.post("/api/v1/token_check") async def count_tokens(request: APITokenCheckRequest): """ Checks the token count for each message in your list This is not part of the OpenAI API spec. """ checkedList = [] async with httpx.AsyncClient() as client: for item in request.prompts: worker_addr = await get_worker_address(item.model, client) response = await client.post( worker_addr + "/model_details", headers=headers, json={"model": item.model}, timeout=WORKER_API_TIMEOUT, ) context_len = response.json()["context_length"] response = await client.post( worker_addr + "/count_token", headers=headers, json={"prompt": item.prompt, "model": item.model}, timeout=WORKER_API_TIMEOUT, ) token_num = response.json()["count"] can_fit = True if token_num + item.max_tokens > context_len: can_fit = False checkedList.append( APITokenCheckResponseItem( fits=can_fit, contextLength=context_len, tokenCount=token_num ) ) return APITokenCheckResponse(prompts=checkedList) @app.post("/api/v1/chat/completions") async def create_chat_completion(request: APIChatCompletionRequest): """Creates a completion for the chat message""" error_check_ret = await check_model(request) if error_check_ret is not None: return error_check_ret error_check_ret = check_requests(request) if error_check_ret is not None: return error_check_ret gen_params = await get_gen_params( request.model, request.messages, temperature=request.temperature, top_p=request.top_p, max_tokens=request.max_tokens, echo=False, stream=request.stream, stop=request.stop, ) if request.repetition_penalty is not None: gen_params["repetition_penalty"] = request.repetition_penalty error_check_ret = await check_length( request, gen_params["prompt"], gen_params["max_new_tokens"] ) if error_check_ret is not None: return error_check_ret if request.stream: generator = chat_completion_stream_generator( request.model, gen_params, request.n ) return StreamingResponse(generator, media_type="text/event-stream") choices = [] chat_completions = [] for i in range(request.n): content = asyncio.create_task(generate_completion(gen_params)) chat_completions.append(content) try: all_tasks = await asyncio.gather(*chat_completions) except Exception as e: return create_error_response(ErrorCode.INTERNAL_ERROR, str(e)) usage = UsageInfo() for i, content in enumerate(all_tasks): if content["error_code"] != 0: return create_error_response(content["error_code"], content["text"]) choices.append( ChatCompletionResponseChoice( index=i, message=ChatMessage(role="assistant", content=content["text"]), finish_reason=content.get("finish_reason", "stop"), ) ) task_usage = UsageInfo.parse_obj(content["usage"]) for usage_key, usage_value in task_usage.dict().items(): setattr(usage, usage_key, getattr(usage, usage_key) + usage_value) return ChatCompletionResponse(model=request.model, choices=choices, usage=usage) ### END GENERAL API - NOT OPENAI COMPATIBLE ### if __name__ == "__main__": parser = argparse.ArgumentParser( description="FastChat ChatGPT-Compatible RESTful API server." ) parser.add_argument("--host", type=str, default="localhost", help="host name") parser.add_argument("--port", type=int, default=8000, help="port number") parser.add_argument( "--controller-address", type=str, default="http://localhost:21001" ) parser.add_argument( "--allow-credentials", action="store_true", help="allow credentials" ) parser.add_argument( "--allowed-origins", type=json.loads, default=["*"], help="allowed origins" ) parser.add_argument( "--allowed-methods", type=json.loads, default=["*"], help="allowed methods" ) parser.add_argument( "--allowed-headers", type=json.loads, default=["*"], help="allowed headers" ) parser.add_argument( "--api-keys", type=lambda s: s.split(","), help="Optional list of comma separated API keys", ) args = parser.parse_args() app.add_middleware( CORSMiddleware, allow_origins=args.allowed_origins, allow_credentials=args.allow_credentials, allow_methods=args.allowed_methods, allow_headers=args.allowed_headers, ) app_settings.controller_address = args.controller_address app_settings.api_keys = args.api_keys logger.info(f"args: {args}") uvicorn.run(app, host=args.host, port=args.port, log_level="info")