import asyncio import json import time from typing import (AsyncGenerator, AsyncIterator, Callable, Dict, Final, List, Optional) from typing import Sequence as GenericSequence from typing import Union from fastapi import Request from vllm.config import ModelConfig from vllm.engine.async_llm_engine import AsyncLLMEngine from vllm.engine.multiprocessing.client import MQLLMEngineClient from vllm.engine.protocol import EngineClient from vllm.entrypoints.chat_utils import (ConversationMessage, apply_hf_chat_template, apply_mistral_chat_template, load_chat_template, parse_chat_messages_futures) from vllm.entrypoints.logger import RequestLogger from vllm.entrypoints.openai.protocol import ( ChatCompletionLogProb, ChatCompletionLogProbs, ChatCompletionLogProbsContent, ChatCompletionNamedToolChoiceParam, ChatCompletionRequest, ChatCompletionResponse, ChatCompletionResponseChoice, ChatCompletionResponseStreamChoice, ChatCompletionStreamResponse, ChatMessage, DeltaFunctionCall, DeltaMessage, DeltaToolCall, ErrorResponse, FunctionCall, RequestResponseMetadata, ToolCall, UsageInfo) from vllm.entrypoints.openai.serving_engine import (BaseModelPath, LoRAModulePath, OpenAIServing, PromptAdapterPath, TextTokensPrompt) from vllm.entrypoints.openai.tool_parsers import ToolParser, ToolParserManager from vllm.inputs import TokensPrompt from vllm.logger import init_logger from vllm.outputs import CompletionOutput, RequestOutput from vllm.sampling_params import BeamSearchParams, SamplingParams from vllm.sequence import Logprob from vllm.tracing import (contains_trace_headers, extract_trace_headers, log_tracing_disabled_warning) from vllm.transformers_utils.tokenizer import AnyTokenizer, MistralTokenizer from vllm.utils import iterate_with_cancellation, random_uuid logger = init_logger(__name__) class OpenAIServingChat(OpenAIServing): def __init__(self, engine_client: EngineClient, model_config: ModelConfig, base_model_paths: List[BaseModelPath], response_role: str, *, lora_modules: Optional[List[LoRAModulePath]], prompt_adapters: Optional[List[PromptAdapterPath]], request_logger: Optional[RequestLogger], chat_template: Optional[str], return_tokens_as_token_ids: bool = False, enable_auto_tools: bool = False, tool_parser: Optional[str] = None): super().__init__(engine_client=engine_client, model_config=model_config, base_model_paths=base_model_paths, lora_modules=lora_modules, prompt_adapters=prompt_adapters, request_logger=request_logger, return_tokens_as_token_ids=return_tokens_as_token_ids) self.response_role = response_role self.use_tool_use_model_template = False self.chat_template = load_chat_template(chat_template) # set up tool use self.enable_auto_tools: bool = enable_auto_tools if self.enable_auto_tools: logger.info( "\"auto\" tool choice has been enabled please note that while" " the parallel_tool_calls client option is preset for " "compatibility reasons, it will be ignored.") self.tool_parser: Optional[Callable[[AnyTokenizer], ToolParser]] = None if self.enable_auto_tools: try: self.tool_parser = ToolParserManager.get_tool_parser( tool_parser) except Exception as e: raise TypeError("Error: --enable-auto-tool-choice requires " f"tool_parser:'{tool_parser}' which has not " "been registered") from e async def create_chat_completion( self, request: ChatCompletionRequest, raw_request: Optional[Request] = None, ) -> Union[AsyncGenerator[str, None], ChatCompletionResponse, ErrorResponse]: """Completion API similar to OpenAI's API. See https://platform.openai.com/docs/api-reference/chat/create for the API specification. This API mimics the OpenAI ChatCompletion API. """ error_check_ret = await self._check_model(request) if error_check_ret is not None: logger.error("Error with model %s", error_check_ret) return error_check_ret # If the engine is dead, raise the engine's DEAD_ERROR. # This is required for the streaming case, where we return a # success status before we actually start generating text :). if self.engine_client.errored: raise self.engine_client.dead_error try: ( lora_request, prompt_adapter_request, ) = self._maybe_get_adapters(request) model_config = self.model_config tokenizer = await self.engine_client.get_tokenizer(lora_request) conversation, mm_data_future = parse_chat_messages_futures( request.messages, model_config, tokenizer) tool_dicts = None if request.tools is None else [ tool.model_dump() for tool in request.tools ] prompt: Union[str, List[int]] is_mistral_tokenizer = isinstance(tokenizer, MistralTokenizer) if is_mistral_tokenizer: prompt = apply_mistral_chat_template( tokenizer, messages=request.messages, chat_template=request.chat_template or self.chat_template, add_generation_prompt=request.add_generation_prompt, continue_final_message=request.continue_final_message, tools=tool_dicts, documents=request.documents, **(request.chat_template_kwargs or {}), ) else: prompt = apply_hf_chat_template( tokenizer, conversation=conversation, chat_template=request.chat_template or self.chat_template, add_generation_prompt=request.add_generation_prompt, continue_final_message=request.continue_final_message, tools=tool_dicts, documents=request.documents, **(request.chat_template_kwargs or {}), ) except Exception as e: logger.exception("Error in applying chat template from request") return self.create_error_response(str(e)) try: mm_data = await mm_data_future except Exception as e: logger.exception("Error in loading multi-modal data") return self.create_error_response(str(e)) # validation for OpenAI tools # tool_choice = "required" is not supported if request.tool_choice == "required": return self.create_error_response( "tool_choice = \"required\" is not supported!") if not is_mistral_tokenizer and request.tool_choice == "auto" and not ( self.enable_auto_tools and self.tool_parser is not None): # for hf tokenizers, "auto" tools requires # --enable-auto-tool-choice and --tool-call-parser return self.create_error_response( "\"auto\" tool choice requires " "--enable-auto-tool-choice and --tool-call-parser to be set") request_id = f"chat-{random_uuid()}" request_metadata = RequestResponseMetadata(request_id=request_id) if raw_request: raw_request.state.request_metadata = request_metadata try: if self.enable_auto_tools and self.tool_parser: request = self.tool_parser(tokenizer).adjust_request( request=request) if isinstance(prompt, str): prompt_inputs = self._tokenize_prompt_input( request, tokenizer, prompt, truncate_prompt_tokens=request.truncate_prompt_tokens, add_special_tokens=request.add_special_tokens, ) else: assert isinstance(prompt, list) and isinstance( prompt[0], int ), "Prompt has to be either a string or a list of token ids" prompt_inputs = TextTokensPrompt( prompt=tokenizer.decode(prompt), prompt_token_ids=prompt) assert prompt_inputs is not None sampling_params: Union[SamplingParams, BeamSearchParams] default_max_tokens = self.max_model_len - len( prompt_inputs["prompt_token_ids"]) if request.use_beam_search: sampling_params = request.to_beam_search_params( default_max_tokens) else: sampling_params = request.to_sampling_params( default_max_tokens) self._log_inputs(request_id, prompt_inputs, params=sampling_params, lora_request=lora_request, prompt_adapter_request=prompt_adapter_request) engine_inputs = TokensPrompt( prompt_token_ids=prompt_inputs["prompt_token_ids"]) if mm_data is not None: engine_inputs["multi_modal_data"] = mm_data is_tracing_enabled = (await self.engine_client.is_tracing_enabled()) trace_headers = None if is_tracing_enabled and raw_request: trace_headers = extract_trace_headers(raw_request.headers) if (not is_tracing_enabled and raw_request and contains_trace_headers(raw_request.headers)): log_tracing_disabled_warning() if isinstance(sampling_params, BeamSearchParams): assert isinstance(self.engine_client, (AsyncLLMEngine, MQLLMEngineClient)), \ "Beam search is only supported with" \ "AsyncLLMEngine and MQLLMEngineClient." result_generator = self.engine_client.beam_search( engine_inputs['prompt_token_ids'], request_id, sampling_params, ) else: result_generator = self.engine_client.generate( engine_inputs, sampling_params, request_id, lora_request=lora_request, trace_headers=trace_headers, prompt_adapter_request=prompt_adapter_request, priority=request.priority, ) except ValueError as e: # TODO: Use a vllm-specific Validation Error return self.create_error_response(str(e)) if raw_request: result_generator = iterate_with_cancellation( result_generator, raw_request.is_disconnected) # Streaming response if request.stream: return self.chat_completion_stream_generator( request, result_generator, request_id, conversation, tokenizer, request_metadata) try: return await self.chat_completion_full_generator( request, result_generator, request_id, conversation, tokenizer, request_metadata) except ValueError as e: # TODO: Use a vllm-specific Validation Error return self.create_error_response(str(e)) def get_chat_request_role(self, request: ChatCompletionRequest) -> str: if request.add_generation_prompt: return self.response_role return request.messages[-1]["role"] async def chat_completion_stream_generator( self, request: ChatCompletionRequest, result_generator: AsyncIterator[RequestOutput], request_id: str, conversation: List[ConversationMessage], tokenizer: AnyTokenizer, request_metadata: RequestResponseMetadata, ) -> AsyncGenerator[str, None]: model_name = self.base_model_paths[0].name created_time = int(time.time()) chunk_object_type: Final = "chat.completion.chunk" first_iteration = True # Send response for each token for each request.n (index) num_choices = 1 if request.n is None else request.n previous_num_tokens = [0] * num_choices finish_reason_sent = [False] * num_choices num_prompt_tokens = 0 if isinstance(request.tool_choice, ChatCompletionNamedToolChoiceParam): tool_choice_function_name = request.tool_choice.function.name else: tool_choice_function_name = None # Determine whether tools are in use with "auto" tool choice tool_choice_auto = ( not tool_choice_function_name and self._should_stream_with_auto_tool_parsing(request)) all_previous_token_ids: Optional[List[List[int]]] if tool_choice_auto: # These are only required in "auto" tool choice case previous_texts = [""] * num_choices all_previous_token_ids = [[]] * num_choices else: previous_texts, all_previous_token_ids = None, None # Prepare the tool parser if it's needed try: if tool_choice_auto and self.tool_parser: tool_parsers: List[Optional[ToolParser]] = [ self.tool_parser(tokenizer) ] * num_choices else: tool_parsers = [None] * num_choices except RuntimeError as e: logger.error("Error in tool parser creation: %s", e) data = self.create_streaming_error_response(str(e)) yield f"data: {data}\n\n" yield "data: [DONE]\n\n" return try: async for res in result_generator: if res.prompt_token_ids is not None: num_prompt_tokens = len(res.prompt_token_ids) if res.encoder_prompt_token_ids is not None: num_prompt_tokens += len(res.encoder_prompt_token_ids) # We need to do it here, because if there are exceptions in # the result_generator, it needs to be sent as the FIRST # response (by the try...catch). if first_iteration: # Send first response for each request.n (index) with # the role role = self.get_chat_request_role(request) # NOTE num_choices defaults to 1 so this usually executes # once per request for i in range(num_choices): tool_parser = tool_parsers[i] choice_data = ChatCompletionResponseStreamChoice( index=i, delta=DeltaMessage( role=role, content="", ), logprobs=None, finish_reason=None) chunk = ChatCompletionStreamResponse( id=request_id, object=chunk_object_type, created=created_time, choices=[choice_data], model=model_name) # if usage should be included if (request.stream_options and request.stream_options.include_usage): # if continuous usage stats are requested, add it if request.stream_options.continuous_usage_stats: usage = UsageInfo( prompt_tokens=num_prompt_tokens, completion_tokens=0, total_tokens=num_prompt_tokens) chunk.usage = usage # otherwise don't else: chunk.usage = None data = chunk.model_dump_json(exclude_unset=True) yield f"data: {data}\n\n" # Send response to echo the input portion of the # last message if request.echo or request.continue_final_message: last_msg_content: str = "" if conversation and "content" in conversation[ -1] and conversation[-1].get("role") == role: last_msg_content = conversation[-1]["content"] or "" if last_msg_content: for i in range(num_choices): choice_data = ( ChatCompletionResponseStreamChoice( index=i, delta=DeltaMessage( content=last_msg_content), logprobs=None, finish_reason=None)) chunk = ChatCompletionStreamResponse( id=request_id, object=chunk_object_type, created=created_time, choices=[choice_data], model=model_name) if (request.stream_options and request.stream_options.include_usage): if (request.stream_options. continuous_usage_stats): usage = UsageInfo( prompt_tokens=num_prompt_tokens, completion_tokens=0, total_tokens=num_prompt_tokens) chunk.usage = usage else: chunk.usage = None data = chunk.model_dump_json( exclude_unset=True) yield f"data: {data}\n\n" first_iteration = False for output in res.outputs: i = output.index tool_parser = tool_parsers[i] if finish_reason_sent[i]: continue if request.logprobs and request.top_logprobs is not None: assert output.logprobs is not None, ( "Did not output logprobs") logprobs = self._create_chat_logprobs( token_ids=output.token_ids, top_logprobs=output.logprobs, tokenizer=tokenizer, num_output_top_logprobs=request.top_logprobs, ) else: logprobs = None delta_text = output.text delta_message: Optional[DeltaMessage] # handle streaming deltas for tools with named tool_choice if tool_choice_function_name: delta_message = DeltaMessage(tool_calls=[ DeltaToolCall(function=DeltaFunctionCall( name=tool_choice_function_name, arguments=delta_text), index=i) ]) # handle streaming deltas for tools with "auto" tool choice elif tool_choice_auto: assert previous_texts is not None assert all_previous_token_ids is not None assert tool_parser is not None #TODO optimize manipulation of these lists previous_text = previous_texts[i] previous_token_ids = all_previous_token_ids[i] current_text = previous_text + delta_text current_token_ids = previous_token_ids + list( output.token_ids) delta_message = ( tool_parser.extract_tool_calls_streaming( previous_text=previous_text, current_text=current_text, delta_text=delta_text, previous_token_ids=previous_token_ids, current_token_ids=current_token_ids, delta_token_ids=output.token_ids, request=request)) # update the previous values for the next iteration previous_texts[i] = current_text all_previous_token_ids[i] = current_token_ids # handle streaming just a content delta else: delta_message = DeltaMessage(content=delta_text) # set the previous values for the next iteration previous_num_tokens[i] += len(output.token_ids) # if the message delta is None (e.g. because it was a # "control token" for tool calls or the parser otherwise # wasn't ready to send a token, then # get the next token without streaming a chunk if delta_message is None: continue if output.finish_reason is None: # Send token-by-token response for each request.n choice_data = ChatCompletionResponseStreamChoice( index=i, delta=delta_message, logprobs=logprobs, finish_reason=None) chunk = ChatCompletionStreamResponse( id=request_id, object=chunk_object_type, created=created_time, choices=[choice_data], model=model_name) # handle usage stats if requested & if continuous if (request.stream_options and request.stream_options.include_usage): if request.stream_options.continuous_usage_stats: completion_tokens = len(output.token_ids) usage = UsageInfo( prompt_tokens=num_prompt_tokens, completion_tokens=completion_tokens, total_tokens=num_prompt_tokens + completion_tokens, ) chunk.usage = usage else: chunk.usage = None data = chunk.model_dump_json(exclude_unset=True) yield f"data: {data}\n\n" # if the model is finished generating else: # check to make sure we haven't "forgotten" to stream # any tokens that were generated but previously # matched by partial json parsing # only happens if we are NOT using guided decoding auto_tools_called = False if tool_parser: auto_tools_called = len( tool_parser.prev_tool_call_arr) > 0 index = len(tool_parser.prev_tool_call_arr ) - 1 if auto_tools_called else 0 else: index = 0 if self._should_check_for_unstreamed_tool_arg_tokens( delta_message, output) and tool_parser: # get the expected call based on partial JSON # parsing which "autocompletes" the JSON expected_call = json.dumps( tool_parser.prev_tool_call_arr[index].get( "arguments", {})) # get what we've streamed so far for arguments # for the current tool actual_call = tool_parser.streamed_args_for_tool[ index] # check to see if there's anything left to stream remaining_call = expected_call.replace( actual_call, "", 1) # set that as a delta message delta_message = DeltaMessage(tool_calls=[ DeltaToolCall(index=index, function=DeltaFunctionCall( arguments=remaining_call). model_dump(exclude_none=True)) ]) # Send the finish response for each request.n only once choice_data = ChatCompletionResponseStreamChoice( index=i, delta=delta_message, logprobs=logprobs, finish_reason=output.finish_reason if not auto_tools_called else "tool_calls", stop_reason=output.stop_reason) chunk = ChatCompletionStreamResponse( id=request_id, object=chunk_object_type, created=created_time, choices=[choice_data], model=model_name) if (request.stream_options and request.stream_options.include_usage): if request.stream_options.continuous_usage_stats: completion_tokens = len(output.token_ids) usage = UsageInfo( prompt_tokens=num_prompt_tokens, completion_tokens=completion_tokens, total_tokens=num_prompt_tokens + completion_tokens, ) chunk.usage = usage else: chunk.usage = None data = chunk.model_dump_json(exclude_unset=True) yield f"data: {data}\n\n" finish_reason_sent[i] = True # once the final token is handled, if stream_options.include_usage # is sent, send the usage if (request.stream_options and request.stream_options.include_usage): completion_tokens = previous_num_tokens[i] final_usage = UsageInfo( prompt_tokens=num_prompt_tokens, completion_tokens=completion_tokens, total_tokens=num_prompt_tokens + completion_tokens, ) final_usage_chunk = ChatCompletionStreamResponse( id=request_id, object=chunk_object_type, created=created_time, choices=[], model=model_name, usage=final_usage) final_usage_data = (final_usage_chunk.model_dump_json( exclude_unset=True, exclude_none=True)) yield f"data: {final_usage_data}\n\n" # report to FastAPI middleware aggregate usage across all choices num_completion_tokens = sum(previous_num_tokens) request_metadata.final_usage_info = UsageInfo( prompt_tokens=num_prompt_tokens, completion_tokens=num_completion_tokens, total_tokens=num_prompt_tokens + num_completion_tokens) except ValueError as e: # TODO: Use a vllm-specific Validation Error logger.error("error in chat completion stream generator: %s", e) data = self.create_streaming_error_response(str(e)) yield f"data: {data}\n\n" # Send the final done message after all response.n are finished yield "data: [DONE]\n\n" async def chat_completion_full_generator( self, request: ChatCompletionRequest, result_generator: AsyncIterator[RequestOutput], request_id: str, conversation: List[ConversationMessage], tokenizer: AnyTokenizer, request_metadata: RequestResponseMetadata, ) -> Union[ErrorResponse, ChatCompletionResponse]: model_name = self.base_model_paths[0].name created_time = int(time.time()) final_res: Optional[RequestOutput] = None try: async for res in result_generator: final_res = res except asyncio.CancelledError: return self.create_error_response("Client disconnected") assert final_res is not None choices: List[ChatCompletionResponseChoice] = [] role = self.get_chat_request_role(request) for output in final_res.outputs: token_ids = output.token_ids out_logprobs = output.logprobs if request.logprobs and request.top_logprobs is not None: assert out_logprobs is not None, "Did not output logprobs" logprobs = self._create_chat_logprobs( token_ids=token_ids, top_logprobs=out_logprobs, num_output_top_logprobs=request.top_logprobs, tokenizer=tokenizer, ) else: logprobs = None # In the OpenAI API the finish_reason is "tools_called" # if the tool choice is auto and the model produced a tool # call. The same is not true for named function calls auto_tools_called = False # if auto tools are not enabled, and a named tool choice using # outlines is not being used if (not self.enable_auto_tools or not self.tool_parser) and not isinstance( request.tool_choice, ChatCompletionNamedToolChoiceParam): message = ChatMessage(role=role, content=output.text) # if the request uses tools and specified a tool choice elif request.tool_choice and type( request.tool_choice) is ChatCompletionNamedToolChoiceParam: message = ChatMessage( role=role, content="", tool_calls=[ ToolCall(function=FunctionCall( name=request.tool_choice.function.name, arguments=output.text)) ]) # if the request doesn't use tool choice # OR specifies to not use a tool elif not request.tool_choice or request.tool_choice == "none": message = ChatMessage(role=role, content=output.text) # handle when there are tools and tool choice is auto elif request.tools and ( request.tool_choice == "auto" or request.tool_choice is None) and self.enable_auto_tools \ and self.tool_parser: try: tool_parser = self.tool_parser(tokenizer) except RuntimeError as e: logger.error("Error in tool parser creation: %s", e) return self.create_error_response(str(e)) tool_call_info = tool_parser.extract_tool_calls( output.text, request=request) # In the OpenAI API the finish_reason is "tools_called" # if the tool choice is auto and the model produced a tool # call. The same is not true for named function calls auto_tools_called = tool_call_info.tools_called if tool_call_info.tools_called: message = ChatMessage(role=role, content=tool_call_info.content, tool_calls=tool_call_info.tool_calls) else: # FOR NOW make it a chat message; we will have to detect # the type to make it later. message = ChatMessage(role=role, content=output.text) # undetermined case that is still important to handle else: logger.error( "Error in chat_completion_full_generator - cannot determine" " if tools should be extracted. Returning a standard chat " "completion.") message = ChatMessage(role=role, content=output.text) choice_data = ChatCompletionResponseChoice( index=output.index, message=message, logprobs=logprobs, finish_reason="tool_calls" if auto_tools_called else output.finish_reason if output.finish_reason else "stop", stop_reason=output.stop_reason) choices.append(choice_data) if request.echo or request.continue_final_message: last_msg_content = "" if conversation and "content" in conversation[-1] and conversation[ -1].get("role") == role: last_msg_content = conversation[-1]["content"] or "" for choice in choices: full_message = last_msg_content + (choice.message.content or "") choice.message.content = full_message assert final_res.prompt_token_ids is not None num_prompt_tokens = len(final_res.prompt_token_ids) if final_res.encoder_prompt_token_ids is not None: num_prompt_tokens += len(final_res.encoder_prompt_token_ids) num_generated_tokens = sum( len(output.token_ids) for output in final_res.outputs) usage = UsageInfo( prompt_tokens=num_prompt_tokens, completion_tokens=num_generated_tokens, total_tokens=num_prompt_tokens + num_generated_tokens, ) request_metadata.final_usage_info = usage response = ChatCompletionResponse( id=request_id, created=created_time, model=model_name, choices=choices, usage=usage, prompt_logprobs=final_res.prompt_logprobs, ) return response def _get_top_logprobs( self, logprobs: Dict[int, Logprob], top_logprobs: Optional[int], tokenizer: AnyTokenizer) -> List[ChatCompletionLogProb]: return [ ChatCompletionLogProb(token=(token := self._get_decoded_token( p[1], p[0], tokenizer, return_as_token_id=self.return_tokens_as_token_ids)), logprob=max(p[1].logprob, -9999.0), bytes=list( token.encode("utf-8", errors="replace"))) for i, p in enumerate(logprobs.items()) if top_logprobs and i < top_logprobs ] def _create_chat_logprobs( self, token_ids: GenericSequence[int], top_logprobs: GenericSequence[Optional[Dict[int, Logprob]]], tokenizer: AnyTokenizer, num_output_top_logprobs: Optional[int] = None, ) -> ChatCompletionLogProbs: """Create OpenAI-style logprobs.""" logprobs_content: List[ChatCompletionLogProbsContent] = [] for i, token_id in enumerate(token_ids): step_top_logprobs = top_logprobs[i] if step_top_logprobs is None: token = tokenizer.decode(token_id) if self.return_tokens_as_token_ids: token = f"token_id:{token_id}" logprobs_content.append( ChatCompletionLogProbsContent( token=token, bytes=list(token.encode("utf-8", errors="replace")), )) else: step_token = step_top_logprobs[token_id] step_decoded = step_token.decoded_token logprobs_content.append( ChatCompletionLogProbsContent( token=self._get_decoded_token( step_token, token_id, tokenizer, self.return_tokens_as_token_ids, ), logprob=max(step_token.logprob, -9999.0), bytes=None if step_decoded is None else list( step_decoded.encode("utf-8", errors="replace")), top_logprobs=self._get_top_logprobs( step_top_logprobs, num_output_top_logprobs, tokenizer, ), )) return ChatCompletionLogProbs(content=logprobs_content) def _should_stream_with_auto_tool_parsing(self, request: ChatCompletionRequest): """ Utility function to check if streamed tokens should go through the tool call parser that was configured. We only want to do this IF user-provided tools are set, a tool parser is configured, "auto" tool choice is enabled, and the request's tool choice field indicates that "auto" tool choice should be used. """ return (request.tools and self.tool_parser and self.enable_auto_tools and request.tool_choice in ['auto', None]) def _should_check_for_unstreamed_tool_arg_tokens( self, delta_message: Optional[DeltaMessage], output: CompletionOutput, ) -> bool: """ Check to see if we should check for unstreamed tool arguments tokens. This is only applicable when auto tool parsing is enabled, the delta is a tool call with arguments. """ # yapf: disable return bool( # if there is a delta message that includes tool calls which # include a function that has arguments output.finish_reason is not None and self.enable_auto_tools and self.tool_parser and delta_message and delta_message.tool_calls and delta_message.tool_calls[0] and delta_message.tool_calls[0].function and delta_message.tool_calls[0].function.arguments is not None )