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vllm-omni/vllm_omni/entrypoints/openai/serving_chat.py
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107 KiB
Python

import asyncio
import base64
import json
import time
import uuid
from collections.abc import AsyncGenerator, AsyncIterator, Callable
from datetime import datetime, timedelta, timezone
from io import BytesIO
from typing import TYPE_CHECKING, Any, Final, Optional, cast
import jinja2
import torch
from fastapi import Request
from PIL import Image
from pydantic import TypeAdapter
from vllm_omni.entrypoints.async_omni import AsyncOmni
from vllm_omni.entrypoints.openai.protocol.chat_completion import OmniChatCompletionResponse
from vllm_omni.inputs.data import OmniDiffusionSamplingParams, OmniTextPrompt
try:
import soundfile
except ImportError:
soundfile = None
from openai.types.chat.chat_completion_audio import ChatCompletionAudio as OpenAIChatCompletionAudio
from vllm.entrypoints.chat_utils import (
ChatCompletionMessageParam,
ChatTemplateContentFormatOption,
ConversationMessage,
get_history_tool_calls_cnt,
make_tool_call_id,
)
from vllm.entrypoints.openai.chat_completion.protocol import (
ChatCompletionNamedToolChoiceParam,
ChatCompletionRequest,
ChatCompletionResponse,
ChatCompletionResponseChoice,
ChatCompletionResponseStreamChoice,
ChatMessage,
)
from vllm.entrypoints.openai.chat_completion.serving import OpenAIServingChat
from vllm.entrypoints.openai.engine.protocol import (
DeltaFunctionCall,
DeltaMessage,
DeltaToolCall,
ErrorInfo,
ErrorResponse,
FunctionCall,
FunctionDefinition,
PromptTokenUsageInfo,
RequestResponseMetadata,
ToolCall,
UsageInfo,
)
from vllm.entrypoints.openai.engine.serving import ChatLikeRequest, clamp_prompt_logprobs
from vllm.entrypoints.openai.parser.harmony_utils import (
get_streamable_parser_for_assistant,
parse_chat_output,
)
from vllm.entrypoints.openai.responses.protocol import ResponsesRequest
from vllm.entrypoints.openai.utils import maybe_filter_parallel_tool_calls
from vllm.entrypoints.utils import should_include_usage
from vllm.inputs.data import PromptType
from vllm.logger import init_logger
from vllm.outputs import RequestOutput
from vllm.reasoning import ReasoningParser
from vllm.renderers import BaseRenderer, merge_kwargs
from vllm.renderers.inputs import TokPrompt
from vllm.sampling_params import SamplingParams
from vllm.tokenizers import TokenizerLike
from vllm.tokenizers import TokenizerLike as AnyTokenizer
from vllm.tokenizers.mistral import (
MistralTokenizer,
maybe_serialize_tool_calls,
truncate_tool_call_ids,
validate_request_params,
)
from vllm.tool_parsers import ToolParser
from vllm.tool_parsers.mistral_tool_parser import MistralToolCall
from vllm.utils.collection_utils import as_list
from vllm_omni.entrypoints.openai.audio_utils_mixin import AudioMixin
from vllm_omni.entrypoints.openai.protocol import OmniChatCompletionStreamResponse
from vllm_omni.entrypoints.openai.protocol.audio import AudioResponse, CreateAudio
from vllm_omni.entrypoints.openai.utils import parse_lora_request
from vllm_omni.lora.request import LoRARequest
from vllm_omni.outputs import OmniRequestOutput
if TYPE_CHECKING:
from vllm_omni.entrypoints.async_omni_diffusion import AsyncOmniDiffusion
logger = init_logger(__name__)
class OmniOpenAIServingChat(OpenAIServingChat, AudioMixin):
"""OpenAI-compatible chat serving for both LLM and Diffusion models.
This class extends OpenAIServingChat to support:
- Standard LLM chat completions
- Diffusion model image generation via chat interface
For diffusion mode, use the `for_diffusion` class method to create an instance.
"""
# Diffusion mode attributes
_diffusion_mode: bool = False
_diffusion_engine: Optional["AsyncOmniDiffusion"] = None
_diffusion_model_name: str = ""
@classmethod
def for_diffusion(
cls,
diffusion_engine: "AsyncOmniDiffusion",
model_name: str,
) -> "OmniOpenAIServingChat":
"""Create a chat serving instance for diffusion models.
Args:
diffusion_engine: The async diffusion engine
model_name: Name of the model being served
Returns:
OmniOpenAIServingChat instance configured for diffusion mode
Note:
Request-level parameters (num_inference_steps, guidance_scale, seed,
height, width, num_frames, fps, etc.) are passed per-request via the API.
"""
instance = cls.__new__(cls)
instance._diffusion_mode = True
instance._diffusion_engine = diffusion_engine
instance._diffusion_model_name = model_name
return instance
async def create_chat_completion(
self,
request: ChatCompletionRequest,
raw_request: Request | None = None,
) -> AsyncGenerator[str, None] | ChatCompletionResponse | ErrorResponse:
"""
Chat 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
Chat Completion API.
For diffusion models, this generates images and returns them
in a chat completion response format.
"""
# Handle diffusion mode
if self._diffusion_mode:
return await self._create_diffusion_chat_completion(request, raw_request)
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 = self._maybe_get_adapters(request, supports_default_mm_loras=True)
model_name = self.models.model_name(lora_request)
renderer = self.renderer
tokenizer = renderer.get_tokenizer()
if tokenizer is None:
tokenizer = await self.engine_client.get_tokenizer()
reasoning_parser: ReasoningParser | None = None
if self.reasoning_parser_cls:
chat_template_kwargs = self._prepare_extra_chat_template_kwargs(
request.chat_template_kwargs,
self.default_chat_template_kwargs,
)
reasoning_parser = self.reasoning_parser_cls(
tokenizer,
chat_template_kwargs=chat_template_kwargs, # type: ignore[call-arg]
)
tool_parser = self.tool_parser
if isinstance(tokenizer, MistralTokenizer):
# because of issues with pydantic we need to potentially
# re-serialize the tool_calls field of the request
# for more info: see comment in `maybe_serialize_tool_calls`
maybe_serialize_tool_calls(request)
truncate_tool_call_ids(request)
validate_request_params(request)
# Check if tool parsing is unavailable (common condition)
tool_parsing_unavailable = (
tool_parser is None and not isinstance(tokenizer, MistralTokenizer) and not self.use_harmony
)
# Validate tool_choice when tool parsing is required but unavailable
if tool_parsing_unavailable and request.tool_choice not in (
None,
"none",
):
if request.tool_choice == "auto" and not self.enable_auto_tools:
# 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'
)
elif request.tool_choice != "auto":
# "required" or named tool requires tool parser
return self.create_error_response(
f'tool_choice="{request.tool_choice}" requires --tool-call-parser to be set'
)
if request.tools is None or (request.tool_choice == "none" and self.exclude_tools_when_tool_choice_none):
tool_dicts = None
else:
tool_dicts = [tool.model_dump() for tool in request.tools]
if not self.use_harmony:
error_check_ret = self._validate_chat_template(
request_chat_template=request.chat_template,
chat_template_kwargs=request.chat_template_kwargs,
trust_request_chat_template=self.trust_request_chat_template,
)
if error_check_ret is not None:
return error_check_ret
chat_template_kwargs = request.chat_template_kwargs or {}
chat_template_kwargs.update(reasoning_effort=request.reasoning_effort)
# Merge chat_template_kwargs with defaults
merged_template_kwargs = self._prepare_extra_chat_template_kwargs(
chat_template_kwargs,
self.default_chat_template_kwargs,
)
conversation, engine_prompts = await self._preprocess_chat(
request,
request.messages,
default_template=request.chat_template or self.chat_template,
default_template_content_format=self.chat_template_content_format,
default_template_kwargs=merged_template_kwargs,
tool_dicts=tool_dicts,
tool_parser=tool_parser,
# OMNI: Additional parameters
renderer=renderer,
add_generation_prompt=request.add_generation_prompt,
continue_final_message=request.continue_final_message,
documents=getattr(request, "documents", None),
add_special_tokens=request.add_special_tokens,
)
else:
should_include_tools = tool_dicts is not None
conversation, engine_prompts = self.openai_serving_render._make_request_with_harmony(
request, should_include_tools
)
except (ValueError, TypeError, RuntimeError, jinja2.TemplateError) as e:
logger.exception("Error in preprocessing prompt inputs")
return self.create_error_response(f"{e} {e.__cause__}")
request_id = f"chatcmpl-{self._base_request_id(raw_request, request.request_id)}"
request_metadata = RequestResponseMetadata(request_id=request_id)
if raw_request:
raw_request.state.request_metadata = request_metadata
output_modalities = getattr(request, "modalities", self.engine_client.output_modalities)
request.modalities = (
output_modalities if output_modalities is not None else self.engine_client.output_modalities
)
# Omni multistage image generation: Stage-0 (AR) should receive a clean
# text prompt (and optional conditioning image/size) so the model's own
# processor can construct the correct inputs.
# If we pass pre-tokenized chat-template ids, GLM-Image can become
# effectively unconditioned and produce nonsense images.
if request.modalities and ("image" in request.modalities):
try:
messages_as_dicts: list[dict[str, Any]] = []
for msg in request.messages:
if hasattr(msg, "model_dump"):
messages_as_dicts.append(msg.model_dump())
elif isinstance(msg, dict):
messages_as_dicts.append(msg)
else:
messages_as_dicts.append(
{
"role": getattr(msg, "role", "user"),
"content": getattr(msg, "content", ""),
}
)
extracted_prompt, reference_images = self._extract_diffusion_prompt_and_images(messages_as_dicts)
if not extracted_prompt:
return self.create_error_response("No text prompt found in messages")
# [NOTE] When sending request via openai client Python library,
# `extra_body` is flattented and merged into the payload's root.
# These extra fields are accessible via `model_extra` property (from Pydantic base class).
# When sending raw request with curl, no flattening happens. Directly read the `extra_body` dict.
extra_body = getattr(request, "extra_body", None)
if not extra_body:
extra_body = request.model_extra or {}
height = extra_body.get("height")
width = extra_body.get("width")
if "size" in extra_body:
try:
size_str = extra_body["size"]
if isinstance(size_str, str) and "x" in size_str.lower():
w, h = size_str.lower().split("x")
width, height = int(w), int(h)
except Exception:
pass
negative_prompt = extra_body.get("negative_prompt")
engine_prompt_image: dict[str, Any] | None = None
is_img2img = False
if reference_images:
# Best-effort decode first reference image for i2i.
try:
img_bytes = base64.b64decode(reference_images[0])
img = Image.open(BytesIO(img_bytes))
engine_prompt_image = {"img2img": img}
is_img2img = True
except Exception:
engine_prompt_image = None
# Override the prompts produced by chat-template preprocessing.
tprompt: OmniTextPrompt = {"prompt": extracted_prompt}
if is_img2img:
tprompt["modalities"] = ["img2img"]
else:
tprompt["modalities"] = ["image"]
if negative_prompt is not None:
tprompt["negative_prompt"] = negative_prompt
# GLM-Image's _call_hf_processor expects target_h/target_w in mm_processor_kwargs
mm_processor_kwargs: dict[str, Any] = {}
if height is not None:
mm_processor_kwargs["target_h"] = height
if width is not None:
mm_processor_kwargs["target_w"] = width
if mm_processor_kwargs:
tprompt["mm_processor_kwargs"] = mm_processor_kwargs
if engine_prompt_image is not None:
tprompt["multi_modal_data"] = engine_prompt_image
engine_prompts = [tprompt]
# Store height/width for applying to diffusion stage sampling params later
_image_gen_height = height
_image_gen_width = width
except Exception as e:
logger.warning("Failed to build image-generation prompt for omni multistage: %s", e)
_image_gen_height = None
_image_gen_width = None
else:
_image_gen_height = None
_image_gen_width = None
# Schedule the request and get the result generator.
generators: list[AsyncGenerator[RequestOutput, None]] = []
try:
for i, engine_prompt in enumerate(engine_prompts):
if hasattr(request, "sampling_params_list"):
sampling_params_list = self._to_sampling_params_list(request.sampling_params_list)
else:
# Use standard OpenAI API parameters for comprehension stage
sampling_params_list = self._build_sampling_params_list_from_request(request)
# Apply user-specified height/width to diffusion stage(s) for image generation
if _image_gen_height is not None or _image_gen_width is not None:
for idx, sp in enumerate(sampling_params_list):
# Diffusion stages typically have height/width attributes
if hasattr(sp, "height") and _image_gen_height is not None:
sp.height = _image_gen_height
if hasattr(sp, "width") and _image_gen_width is not None:
sp.width = _image_gen_width
self._log_inputs(
request_id,
engine_prompt,
params_list=sampling_params_list,
lora_request=lora_request,
)
generator = self.engine_client.generate(
prompt=engine_prompt,
request_id=request_id,
sampling_params_list=sampling_params_list,
output_modalities=output_modalities,
)
generators.append(generator)
except ValueError as e:
return self.create_error_response(e)
assert len(generators) == 1
(result_generator,) = generators
# Streaming response
if request.stream:
return self.chat_completion_stream_generator(
request,
result_generator,
request_id,
model_name,
conversation,
tokenizer,
request_metadata,
reasoning_parser,
)
try:
return await self.chat_completion_full_generator(
request,
result_generator,
request_id,
model_name,
conversation,
tokenizer,
request_metadata,
reasoning_parser,
)
except ValueError as e:
return self.create_error_response(e)
async def _preprocess_chat(
self,
request: ChatLikeRequest | ResponsesRequest,
messages: list[ChatCompletionMessageParam],
default_template: str | None,
default_template_content_format: ChatTemplateContentFormatOption,
default_template_kwargs: dict[str, Any] | None = None,
tool_dicts: list[dict[str, Any]] | None = None,
tool_parser: Callable[[TokenizerLike], ToolParser] | None = None,
# OMNI: Additional parameters for backward compatibility
renderer: BaseRenderer | None = None,
add_generation_prompt: bool = True,
continue_final_message: bool = False,
documents: list[dict[str, str]] | None = None,
add_special_tokens: bool = False,
) -> tuple[list[ConversationMessage], list[TokPrompt]]:
if renderer is None:
renderer = self.renderer
# Keep OMNI compatibility args wired while delegating rendering
# to the upstream async renderer pipeline.
default_template_kwargs = merge_kwargs(
default_template_kwargs,
dict(
tools=tool_dicts,
documents=documents,
add_generation_prompt=add_generation_prompt,
continue_final_message=continue_final_message,
add_special_tokens=add_special_tokens,
tokenize=isinstance(renderer.tokenizer, MistralTokenizer),
),
)
tok_params = request.build_tok_params(self.model_config)
chat_params = request.build_chat_params(
default_template,
default_template_content_format,
).with_defaults(default_template_kwargs)
# OMNI: When use_audio_in_video=True, the qwen2_5_omni_thinker mm
# processor asserts that audio items are present alongside video items
# (inside render_chat_async). We must inject audio_url items into the
# messages BEFORE calling render_chat_async so the mm processor can
# count them correctly during tokenisation.
mm_proc_kw = getattr(request, "mm_processor_kwargs", None) or {}
if mm_proc_kw.get("use_audio_in_video", False):
messages = await self._inject_audio_from_video_urls(messages)
(conversation,), (engine_prompt,) = await renderer.render_chat_async(
[messages],
chat_params,
tok_params,
prompt_extras={
k: v for k in ("mm_processor_kwargs", "cache_salt") if (v := getattr(request, k, None)) is not None
},
)
tokenizer = renderer.get_tokenizer()
# tool parsing is done only if a tool_parser has been set and if
# tool_choice is not "none" (if tool_choice is "none" but a tool_parser
# is set, we want to prevent parsing a tool_call hallucinated by the LLM
should_parse_tools = tool_parser is not None and (
hasattr(request, "tool_choice") and request.tool_choice != "none"
)
if should_parse_tools:
if not isinstance(request, ChatCompletionRequest):
msg = "Tool usage is only supported for Chat Completions API"
raise NotImplementedError(msg)
request = tool_parser(tokenizer).adjust_request( # type: ignore
request=request
)
# Preserve a clean text prompt for downstream stages (e.g., GLM-Image diffusion).
# For image generation, we want the raw user caption instead of a rendered template.
# But for multimodal comprehension (img2text), we MUST keep the rendered prompt
# containing image tokens.
req_modalities = getattr(request, "modalities", [])
if req_modalities and ("image" in req_modalities):
messages_as_dicts: list[dict[str, Any]] = []
for msg in messages:
if hasattr(msg, "model_dump"):
messages_as_dicts.append(msg.model_dump())
elif isinstance(msg, dict):
messages_as_dicts.append(msg)
else:
messages_as_dicts.append(
{
"role": getattr(msg, "role", "user"),
"content": getattr(msg, "content", ""),
}
)
extracted_prompt, _ = self._extract_diffusion_prompt_and_images(messages_as_dicts)
if extracted_prompt:
engine_prompt["prompt"] = extracted_prompt
mm_processor_kwargs = getattr(request, "mm_processor_kwargs", None)
if mm_processor_kwargs is not None:
engine_prompt["mm_processor_kwargs"] = mm_processor_kwargs
if hasattr(request, "cache_salt") and request.cache_salt is not None:
engine_prompt["cache_salt"] = request.cache_salt
return conversation, [engine_prompt]
async def _inject_audio_from_video_urls(
self,
messages: list[ChatCompletionMessageParam],
) -> list[ChatCompletionMessageParam]:
"""Pre-extract audio from video URLs and inject as audio_url content items.
When use_audio_in_video=True, the qwen2_5_omni_thinker multimodal
processor requires that the number of audio items equals the number of
video items (it subtracts mm_counts["video"] from mm_counts["audio"]).
The client only sends video_url items; this method adds the matching
audio_url items on the server side before the renderer processes them.
"""
import io
from vllm_omni.entrypoints.chat_utils import extract_audio_from_video_async
new_messages: list[ChatCompletionMessageParam] = []
for msg in messages:
content = msg.get("content") if isinstance(msg, dict) else getattr(msg, "content", None)
if not isinstance(content, list):
new_messages.append(msg)
continue
video_urls = [
part.get("video_url", {}).get("url")
for part in content
if isinstance(part, dict) and part.get("type") == "video_url" and part.get("video_url", {}).get("url")
]
if not video_urls:
new_messages.append(msg)
continue
audios = await asyncio.gather(*(extract_audio_from_video_async(u) for u in video_urls))
audio_items: list[dict] = []
for audio_array, sample_rate in audios:
buf = io.BytesIO()
if soundfile is not None:
soundfile.write(buf, audio_array, samplerate=int(sample_rate), format="WAV")
else:
import struct
import numpy as np
audio_np = np.asarray(audio_array, dtype=np.float32)
sr = int(sample_rate)
num_channels = 1
bits_per_sample = 32
num_frames = len(audio_np)
data_size = num_frames * num_channels * (bits_per_sample // 8)
# Write minimal RIFF/WAV header
buf.write(b"RIFF")
buf.write(struct.pack("<I", 36 + data_size))
buf.write(b"WAVE")
buf.write(b"fmt ")
buf.write(
struct.pack(
"<IHHIIHH",
16,
3,
num_channels,
sr,
sr * num_channels * (bits_per_sample // 8),
num_channels * (bits_per_sample // 8),
bits_per_sample,
)
)
buf.write(b"data")
buf.write(struct.pack("<I", data_size))
buf.write(audio_np.tobytes())
audio_b64 = base64.b64encode(buf.getvalue()).decode()
audio_items.append(
{
"type": "audio_url",
"audio_url": {"url": f"data:audio/wav;base64,{audio_b64}"},
}
)
new_content = list(content) + audio_items
if isinstance(msg, dict):
new_msg = {**msg, "content": new_content}
else:
new_msg = msg.model_copy(update={"content": new_content})
new_messages.append(new_msg)
return new_messages
def _to_sampling_params_list(self, sampling_params_list: list[dict]) -> list[SamplingParams]:
final_sampling_params_list = []
for sampling_params in sampling_params_list:
if isinstance(sampling_params, dict):
final_sampling_params_list.append(SamplingParams(**sampling_params))
elif isinstance(sampling_params, SamplingParams):
final_sampling_params_list.append(sampling_params)
else:
raise ValueError(f"Invalid sampling params: {sampling_params}")
return final_sampling_params_list
def _get_comprehension_stage_index(self) -> int:
for idx, stage in enumerate(self.engine_client.stage_configs):
if stage.is_comprehension:
return idx
raise ValueError("No comprehension stage (is_comprehension=True) found in stage configs")
# OpenAI API standard sampling parameters that can be safely overridden.
# These are the most commonly used parameters with compatible types
# between ChatCompletionRequest and SamplingParams.
# Users who need more control can use sampling_params_list in extra_body.
_OPENAI_SAMPLING_FIELDS: set[str] = {
"temperature",
"top_p",
"top_k",
"max_tokens",
"min_tokens",
"seed",
"ignore_eos",
"stop",
"stop_token_ids",
"frequency_penalty",
"presence_penalty",
}
def _apply_request_overrides(
self,
default_params: SamplingParams,
request: ChatCompletionRequest,
) -> SamplingParams:
"""Clone default params and override with user-provided request values.
Starts with YAML defaults and only overrides fields that the user
explicitly provided (non-None values) in the request.
Args:
default_params: Default SamplingParams from stage config YAML.
request: The chat completion request containing user-provided values.
Returns:
New SamplingParams with YAML defaults overridden by request values.
"""
params = default_params.clone()
for field_name in self._OPENAI_SAMPLING_FIELDS:
value = getattr(request, field_name, None)
if value is not None:
setattr(params, field_name, value)
return params
def _build_sampling_params_list_from_request(
self,
request: ChatCompletionRequest,
) -> list[SamplingParams]:
"""Build sampling_params_list using standard OpenAI API parameters.
For the comprehension stage, starts with YAML defaults and overrides with
user-provided request values. For other stages, uses cloned YAML defaults.
This approach ensures all YAML defaults (including seed, detokenize, etc.)
are preserved while allowing users to override specific parameters.
Args:
request: The chat completion request containing OpenAI API parameters.
Returns:
List of SamplingParams, one for each stage.
"""
default_params_list = self.engine_client.default_sampling_params_list
comprehension_idx = self._get_comprehension_stage_index()
sampling_params_list = []
for idx, default_params in enumerate(default_params_list):
if isinstance(default_params, dict):
default_params = SamplingParams(**default_params)
if idx == comprehension_idx:
params = self._apply_request_overrides(default_params, request)
sampling_params_list.append(params)
else:
# For other stages, clone default params
sampling_params_list.append(default_params.clone())
return sampling_params_list
def _log_inputs(
self,
request_id: str,
inputs: PromptType | TokPrompt,
params_list: list[SamplingParams] | None,
lora_request: LoRARequest | None,
) -> None:
if self.request_logger is None:
return
components = self._extract_prompt_components(inputs)
self.request_logger.log_inputs(
request_id,
components.text,
components.token_ids,
components.embeds,
params=params_list,
lora_request=lora_request,
)
async def chat_completion_stream_generator(
self,
request: ChatCompletionRequest,
result_generator: AsyncIterator[RequestOutput],
request_id: str,
model_name: str,
conversation: list[ConversationMessage],
tokenizer: AnyTokenizer,
request_metadata: RequestResponseMetadata,
reasoning_parser: ReasoningParser | None = None,
):
created_time = int(time.time())
chunk_object_type: Final = "chat.completion.chunk"
first_iteration_dict = {}
assert hasattr(request, "modalities") and request.modalities is not None, (
"Streaming request must specify output modalities"
)
for modality in request.modalities:
first_iteration_dict[modality] = 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
num_cached_tokens = None
if self.use_harmony:
harmony_parsers = [get_streamable_parser_for_assistant() for _ in range(num_choices)]
harmony_tools_streamed = [False] * num_choices
tools_streamed = [False] * num_choices
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: list[list[int]] | None
function_name_returned = [False] * num_choices
if self.tool_call_id_type == "kimi_k2":
history_tool_call_cnt = get_history_tool_calls_cnt(conversation)
else:
history_tool_call_cnt = 0
# Always track previous_texts for comprehensive output logging
previous_texts = [""] * num_choices
# Only one of these will be used, thus previous_texts and
# all_previous_token_ids will not be used twice in the same iteration.
if tool_choice_auto or reasoning_parser:
# These are only required in "auto" tool choice case
all_previous_token_ids = [[]] * num_choices
# For reasoning parser and tool call all enabled
added_content_delta_arr = [False] * num_choices
reasoning_end_arr = [False] * num_choices
else:
all_previous_token_ids = None
# Prepare the tool parser if it's needed
try:
if tool_choice_auto and self.tool_parser:
tool_parsers: list[ToolParser | None] = [self.tool_parser(tokenizer)] * num_choices
else:
tool_parsers = [None] * num_choices
except Exception as e:
logger.exception("Error in tool parser creation.")
data = self.create_streaming_error_response(e)
yield f"data: {data}\n\n"
yield "data: [DONE]\n\n"
return
stream_options = request.stream_options
include_usage, include_continuous_usage = should_include_usage(stream_options, self.enable_force_include_usage)
last_metrics: dict[str, Any] | None = None
try:
async for omni_res in result_generator:
final_output_type = omni_res.final_output_type
res = omni_res.request_output
if final_output_type not in first_iteration_dict:
logger.warning(f"final output type: {final_output_type} is not needed by the request")
continue
if omni_res.metrics:
last_metrics = omni_res.metrics
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)
# Initialize role before conditional blocks to avoid UnboundLocalError
# when handling audio/image responses
role = self.get_chat_request_role(request)
# 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_dict[final_output_type] and final_output_type == "text":
num_cached_tokens = res.num_cached_tokens
# Send first response for each choice with role
# NOTE: num_choices defaults to 1 so this usually executes once per request
for i in range(num_choices):
choice_data = ChatCompletionResponseStreamChoice(
index=i,
delta=DeltaMessage(
role=role,
content="",
),
logprobs=None,
finish_reason=None,
)
# return prompt_token_ids at the first chunk ever
chunk = OmniChatCompletionStreamResponse(
id=request_id,
object=chunk_object_type,
created=created_time,
choices=[choice_data],
model=model_name,
prompt_token_ids=(res.prompt_token_ids if request.return_token_ids else None),
modality=final_output_type,
)
# if continuous usage stats are requested, add it
if include_continuous_usage:
chunk.usage = UsageInfo(
prompt_tokens=num_prompt_tokens,
completion_tokens=0,
total_tokens=num_prompt_tokens,
)
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:
last_msg_content: str | list[dict[str, 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 = OmniChatCompletionStreamResponse(
id=request_id,
object=chunk_object_type,
created=created_time,
choices=[choice_data],
model=model_name,
modality=final_output_type,
)
if include_continuous_usage:
chunk.usage = UsageInfo(
prompt_tokens=num_prompt_tokens,
completion_tokens=0,
total_tokens=num_prompt_tokens,
)
data = chunk.model_dump_json(exclude_unset=True)
yield f"data: {data}\n\n"
first_iteration_dict[final_output_type] = False
if final_output_type == "text":
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,
return_as_token_id=request.return_tokens_as_token_ids,
)
else:
logprobs = None
if self.use_harmony:
harmony_parser = harmony_parsers[i]
prev_recipient = harmony_parser.current_recipient
delta_text = ""
for token_id in output.token_ids:
harmony_parser.process(token_id)
delta_text += harmony_parser.last_content_delta or ""
cur_channel = harmony_parser.current_channel
cur_recipient = harmony_parser.current_recipient
else:
# output.text is cumulative, extract only the delta portion
previous_text = previous_texts[i] if previous_texts else ""
if output.text is not None:
delta_text = output.text[len(previous_text) :]
else:
delta_text = ""
if not delta_text and not output.token_ids and not previous_num_tokens[i]:
# Chunked prefill case, don't return empty chunks
continue
delta_message: DeltaMessage | None
# just update previous_texts and previous_token_ids
if tool_choice_auto or reasoning_parser:
assert previous_texts is not None
assert all_previous_token_ids is not None
previous_text = previous_texts[i]
previous_token_ids = all_previous_token_ids[i]
current_text = previous_text + delta_text
# avoid the None + list error.
if previous_token_ids:
current_token_ids = previous_token_ids + as_list(output.token_ids)
else:
current_token_ids = as_list(output.token_ids)
if self.use_harmony:
if cur_channel == "final":
delta_message = DeltaMessage(content=delta_text)
elif cur_channel == "analysis":
if request.include_reasoning:
delta_message = DeltaMessage(reasoning=delta_text)
else:
delta_message = None
elif (
cur_channel == "commentary" and cur_recipient and cur_recipient.startswith("functions.")
):
# Count completed tool calls to determine index
base_index = 0
for msg in harmony_parser.messages:
if (
msg.channel == "commentary"
and msg.recipient
and msg.recipient.startswith("functions.")
):
base_index += 1
if prev_recipient != cur_recipient:
tool_name = cur_recipient.split("functions.", 1)[1]
delta_message = DeltaMessage(
tool_calls=[
DeltaToolCall(
id=make_tool_call_id(),
type="function",
function=DeltaFunctionCall(
name=tool_name,
arguments="",
),
index=base_index,
)
]
)
elif delta_text:
delta_message = DeltaMessage(
tool_calls=[
DeltaToolCall(
index=base_index,
function=DeltaFunctionCall(arguments=delta_text),
)
]
)
else:
delta_message = None
if delta_message is not None:
harmony_tools_streamed[i] = True
else:
delta_message = None
# handle streaming deltas for tools with named tool_choice
elif tool_choice_function_name:
if (
reasoning_parser
and not reasoning_end_arr[i]
and not reasoning_parser.is_reasoning_end(previous_token_ids)
):
assert reasoning_parser is not None
delta_message = reasoning_parser.extract_reasoning_streaming(
previous_text,
current_text,
delta_text,
previous_token_ids,
current_token_ids,
output.token_ids,
)
# When encountering think end id in delta_token_ids
# or think end id in prompt_token_ids
# i.e {"enable_thinking": False},
# set reasoning status to end.
# Only keep 'content', remove 'reasoning'.
if reasoning_parser.is_reasoning_end(as_list(output.token_ids)) or (
res.prompt_token_ids and reasoning_parser.is_reasoning_end(res.prompt_token_ids)
):
reasoning_end_arr[i] = True
if delta_message and delta_message.content:
# This need to be added to next `delta_text`
current_text = delta_message.content
delta_message.content = None
else:
current_text = ""
else:
# Just to add remaining `content`
if reasoning_parser:
delta_text = previous_text + delta_text
current_text = ""
if function_name_returned[i]:
delta_tool_call = DeltaToolCall(
function=DeltaFunctionCall(arguments=delta_text),
index=i,
)
else:
delta_tool_call = DeltaToolCall(
id=make_tool_call_id(),
type="function",
function=DeltaFunctionCall(
name=tool_choice_function_name,
arguments=delta_text,
),
index=i,
)
function_name_returned[i] = True
delta_message = DeltaMessage(
tool_calls=[
delta_tool_call,
]
)
tools_streamed[i] = True
elif request.tool_choice == "required":
assert previous_texts is not None
previous_text = previous_texts[i]
current_text = previous_text + delta_text
fn_name_returned = function_name_returned[i]
output_token_ids = as_list(output.token_ids)
if (
reasoning_parser is not None
and not reasoning_end_arr[i]
and res.prompt_token_ids
and reasoning_parser.is_reasoning_end(res.prompt_token_ids)
):
reasoning_end_arr[i] = True
if reasoning_parser and not reasoning_end_arr[i]:
delta_message = reasoning_parser.extract_reasoning_streaming(
previous_text,
current_text,
delta_text,
previous_token_ids,
current_token_ids,
output_token_ids,
)
if reasoning_parser.is_reasoning_end(output_token_ids):
reasoning_end_arr[i] = True
if delta_message and delta_message.content:
current_text = delta_message.content
delta_message.content = None
else:
# reasoning ended
current_text = ""
else:
# either finished reasoning or no reasoning at all
content = current_text
delta_message, function_name_returned[i] = self.extract_tool_call_required_streaming(
previous_text=previous_text,
current_text=content,
delta_text=delta_text,
function_name_returned=fn_name_returned,
tool_call_idx=history_tool_call_cnt,
)
if (
delta_message
and delta_message.tool_calls
and delta_message.tool_calls[0].id is not None
):
history_tool_call_cnt += 1
tools_streamed[i] = True
# handle streaming deltas for tools with "auto" tool choice
# and reasoning parser
elif tool_choice_auto and reasoning_parser:
assert tool_parser is not None
assert reasoning_parser is not None
assert added_content_delta_arr is not None
assert reasoning_end_arr is not None
output_token_ids = as_list(output.token_ids)
if not reasoning_end_arr[i]:
delta_message = reasoning_parser.extract_reasoning_streaming(
previous_text,
current_text,
delta_text,
previous_token_ids,
current_token_ids,
output_token_ids,
)
# When encountering think end id in prompt_token_ids
# i.e {"enable_thinking": False},
# set reasoning status to end.
# Remove the text and token ids related
# to 'reasoning'.
if res.prompt_token_ids and reasoning_parser.is_reasoning_end(res.prompt_token_ids):
reasoning_end_arr[i] = True
current_token_ids = output_token_ids
if delta_message and delta_message.content:
current_text = delta_message.content
delta_message.content = None
else:
current_text = ""
# When encountering think end id in delta_token_ids,
# set reasoning status to end.
# Remove the text and token ids related
# to 'reasoning'.
if reasoning_parser.is_reasoning_end(output_token_ids):
reasoning_end_arr[i] = True
current_token_ids = reasoning_parser.extract_content_ids(output_token_ids)
if delta_message and delta_message.content:
current_text = delta_message.content
delta_message.content = None
else:
current_text = ""
# handle tool calls only after reasoning is done,
else:
delta_token_ids = output_token_ids
# First time to tool call,
# add the remaining text and token ids
# to delta from previous
if not added_content_delta_arr[i]:
added_content_delta_arr[i] = True
previous_text = ""
previous_token_ids = []
delta_text = current_text
delta_token_ids = current_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=delta_token_ids,
request=request,
)
if delta_message and delta_message.tool_calls:
tools_streamed[i] = True
# when only tool calls
elif tool_choice_auto:
assert tool_parser is not None
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,
)
if delta_message and delta_message.tool_calls:
tools_streamed[i] = True
# when only reasoning
elif reasoning_parser:
delta_message = reasoning_parser.extract_reasoning_streaming(
previous_text,
current_text,
delta_text,
previous_token_ids,
current_token_ids,
output.token_ids,
)
# handle streaming just a content delta
else:
delta_message = DeltaMessage(content=delta_text)
# update the previous values for the next iteration
if (tool_choice_auto or reasoning_parser) and not self.use_harmony:
assert previous_texts is not None
assert all_previous_token_ids is not None
previous_texts[i] = current_text
all_previous_token_ids[i] = current_token_ids
else:
# Update for comprehensive logging even in simple case
assert previous_texts is not None
previous_texts[i] += 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:
if output.finish_reason is None and not request.return_token_ids:
continue
delta_message = DeltaMessage()
# Log streaming delta if output logging is enabled
if self.enable_log_outputs and self.request_logger:
delta_content = ""
if delta_message.content:
delta_content = delta_message.content
elif delta_message.tool_calls:
delta_content = "".join(
tc.function.arguments
for tc in delta_message.tool_calls
if tc.function and tc.function.arguments
)
if delta_content:
self.request_logger.log_outputs(
request_id=request_id,
outputs=delta_content,
output_token_ids=as_list(output.token_ids),
finish_reason=output.finish_reason,
is_streaming=True,
delta=True,
)
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,
token_ids=(as_list(output.token_ids) if request.return_token_ids else None),
)
# 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 structured outputs
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:
latest_delta_len = 0
if (
isinstance(
delta_message.tool_calls[0].function,
DeltaFunctionCall,
)
) and isinstance(delta_message.tool_calls[0].function.arguments, str):
latest_delta_len = len(delta_message.tool_calls[0].function.arguments)
# get the expected call based on partial JSON
# parsing which "autocompletes" the JSON.
# Tool parsers (e.g. Qwen3Coder) store
# arguments as a JSON string in
# prev_tool_call_arr. Calling json.dumps()
# on an already-serialized string would
# double-serialize it (e.g. '{"k":1}' becomes
# '"{\\"k\\":1}"'), which then causes the
# replace() below to fail and append the
# entire double-serialized string as a
# spurious final delta.
args = tool_parser.prev_tool_call_arr[index].get("arguments", {})
if isinstance(args, str):
expected_call = args
else:
expected_call = json.dumps(args, ensure_ascii=False)
# get what we've streamed so far for arguments
# for the current tool
actual_call = tool_parser.streamed_args_for_tool[index]
if latest_delta_len > 0:
actual_call = actual_call[:-latest_delta_len]
# 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
# In OpenAI's API, when a tool is called, the
# finish_reason is:
# "tool_calls" for "auto" or "required" tool calls,
# and "stop" for named tool calls.
if (
auto_tools_called
or (tools_streamed[i] and not tool_choice_function_name)
or (self.use_harmony and harmony_tools_streamed[i])
):
finish_reason_ = "tool_calls"
else:
finish_reason_ = output.finish_reason if output.finish_reason else "stop"
choice_data = ChatCompletionResponseStreamChoice(
index=i,
delta=delta_message,
logprobs=logprobs,
finish_reason=finish_reason_,
stop_reason=output.stop_reason,
token_ids=(as_list(output.token_ids) if request.return_token_ids else None),
)
finish_reason_sent[i] = True
choice_data = maybe_filter_parallel_tool_calls(choice_data, request)
chunk = OmniChatCompletionStreamResponse(
id=request_id,
object=chunk_object_type,
created=created_time,
choices=[choice_data],
model=model_name,
modality=final_output_type,
metrics=omni_res.metrics,
)
# handle usage stats if requested & if continuous
if include_continuous_usage:
completion_tokens = previous_num_tokens[i]
chunk.usage = UsageInfo(
prompt_tokens=num_prompt_tokens,
completion_tokens=completion_tokens,
total_tokens=num_prompt_tokens + completion_tokens,
)
data = chunk.model_dump_json(exclude_unset=True)
yield f"data: {data}\n\n"
elif final_output_type == "audio":
role = self.get_chat_request_role(request)
choices_data = self._create_audio_choice(omni_res, role, request, stream=True)
chunk = OmniChatCompletionStreamResponse(
id=request_id,
object=chunk_object_type,
created=created_time,
choices=choices_data,
model=model_name,
modality=final_output_type,
)
chunk.usage = UsageInfo(
prompt_tokens=num_prompt_tokens,
completion_tokens=0,
total_tokens=num_prompt_tokens,
)
data = chunk.model_dump_json(exclude_unset=True)
yield f"data: {data}\n\n"
else:
logger.warning(f"Unsupported streaming final output type: {final_output_type}")
continue
# once the final token is handled, if stream_options.include_usage
# is sent, send the usage
if include_usage:
completion_tokens = sum(previous_num_tokens)
final_usage = UsageInfo(
prompt_tokens=num_prompt_tokens,
completion_tokens=completion_tokens,
total_tokens=num_prompt_tokens + completion_tokens,
)
if self.enable_prompt_tokens_details and num_cached_tokens:
final_usage.prompt_tokens_details = PromptTokenUsageInfo(cached_tokens=num_cached_tokens)
final_usage_chunk = OmniChatCompletionStreamResponse(
id=request_id,
object=chunk_object_type,
created=created_time,
choices=[],
model=model_name,
usage=final_usage,
metrics=last_metrics,
)
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,
)
# Log complete streaming response if output logging is enabled
if self.enable_log_outputs and self.request_logger:
# Log the complete response for each choice
for i in range(num_choices):
full_text = (
previous_texts[i]
if previous_texts and i < len(previous_texts)
else f"<streaming_complete: {previous_num_tokens[i]} tokens>"
)
self.request_logger.log_outputs(
request_id=request_id,
outputs=full_text,
output_token_ids=None, # Consider also logging all token IDs
finish_reason="streaming_complete",
is_streaming=True,
delta=False,
)
except Exception as e:
logger.exception("Error in chat completion stream generator.")
data = self.create_streaming_error_response(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,
model_name: str,
conversation: list[ConversationMessage],
tokenizer: TokenizerLike,
request_metadata: RequestResponseMetadata,
reasoning_parser: ReasoningParser | None = None,
) -> ErrorResponse | OmniChatCompletionResponse:
created_time = int(time.time())
final_res: RequestOutput | None = None
final_outputs: list[OmniRequestOutput] = []
try:
async for res in result_generator:
final_outputs.append(res)
except asyncio.CancelledError:
return self.create_error_response("Client disconnected")
except ValueError as e:
return self.create_error_response(e)
assert final_outputs is not None
choices: list[ChatCompletionResponseChoice] = []
usage = UsageInfo(prompt_tokens=0, completion_tokens=0, total_tokens=0)
role = self.get_chat_request_role(request)
prompt_logprobs = None
prompt_token_ids = None
kv_transfer_params = None
response_metrics: dict[str, Any] | None = None
# Build requested modalities set for filtering
requested_modalities = (
set(request.modalities) if hasattr(request, "modalities") and request.modalities else None
)
for omni_outputs in final_outputs:
choices_data = []
if omni_outputs.request_output is not None and not getattr(omni_outputs.request_output, "finished", False):
continue
# Filter outputs based on requested modalites
if requested_modalities is not None and omni_outputs.final_output_type not in requested_modalities:
logger.warning(f"final output type: {omni_outputs.final_output_type} is not needed by the request")
continue
if omni_outputs.final_output_type == "text":
(
choices_data,
usage,
prompt_logprobs,
prompt_token_ids,
kv_transfer_params,
) = self._create_text_choice(
request,
omni_outputs,
tokenizer,
conversation,
role,
reasoning_parser,
)
elif omni_outputs.final_output_type == "audio":
choices_data = self._create_audio_choice(omni_outputs, role, request, stream=False)
elif omni_outputs.final_output_type == "image":
choices_data = self._create_image_choice(omni_outputs, role, request, stream=False)
else:
logger.warning(f"Unsupported final output type: {omni_outputs.final_output_type}")
continue
if omni_outputs.metrics:
response_metrics = omni_outputs.metrics
choices.extend(choices_data)
response = OmniChatCompletionResponse(
id=request_id,
created=created_time,
model=model_name,
choices=choices,
usage=usage,
prompt_logprobs=prompt_logprobs,
prompt_token_ids=prompt_token_ids,
kv_transfer_params=kv_transfer_params,
metrics=response_metrics,
)
# Log complete response if output logging is enabled
if self.enable_log_outputs and self.request_logger:
for choice in choices:
output_text = ""
if choice.message.content:
output_text = choice.message.content
elif choice.message.tool_calls:
# For tool calls, log the function name and arguments
tool_call_descriptions = []
for tc in choice.message.tool_calls:
if hasattr(tc.function, "name") and hasattr(tc.function, "arguments"):
tool_call_descriptions.append(f"{tc.function.name}({tc.function.arguments})")
tool_calls_str = ", ".join(tool_call_descriptions)
output_text = f"[tool_calls: {tool_calls_str}]"
if output_text:
# Get the corresponding output token IDs
output_token_ids = None
if choice.index < len(final_res.outputs):
output_token_ids = final_res.outputs[choice.index].token_ids
self.request_logger.log_outputs(
request_id=request_id,
outputs=output_text,
output_token_ids=output_token_ids,
finish_reason=choice.finish_reason,
is_streaming=False,
delta=False,
)
return response
def _create_text_choice(
self,
request: ChatCompletionRequest,
omni_outputs: OmniRequestOutput,
tokenizer: TokenizerLike,
conversation: list[ConversationMessage],
role: str,
reasoning_parser: ReasoningParser | None = None,
):
final_res = omni_outputs.request_output
if self.tool_call_id_type == "kimi_k2":
history_tool_call_cnt = get_history_tool_calls_cnt(conversation)
else:
history_tool_call_cnt = 0
choices: list[ChatCompletionResponseChoice] = []
for output in final_res.outputs:
token_ids = output.token_ids
out_logprobs = output.logprobs
tool_call_info = None
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,
return_as_token_id=request.return_tokens_as_token_ids,
)
else:
logprobs = None
if self.use_harmony:
reasoning_content, content, _ = parse_chat_output(token_ids)
if not request.include_reasoning:
reasoning_content = None
if self.tool_parser is not None:
tool_parser = self.tool_parser(tokenizer)
# NOTE: We use token_ids for openai tool parser
tool_call_info = tool_parser.extract_tool_calls(
"",
request=request,
token_ids=token_ids, # type: ignore
)
content = tool_call_info.content
message = ChatMessage(
role=role,
reasoning_content=reasoning_content,
content=content,
tool_calls=tool_call_info.tool_calls,
)
else:
message = ChatMessage(
role=role,
reasoning_content=reasoning_content,
content=content,
)
choice_data = ChatCompletionResponseChoice(
index=output.index,
message=message,
logprobs=logprobs,
finish_reason=(
"tool_calls"
if (tool_call_info is not None and tool_call_info.tools_called)
else (output.finish_reason if output.finish_reason else "stop")
),
stop_reason=output.stop_reason,
)
choices.append(choice_data)
continue
if reasoning_parser:
# If the reasoning parser is enabled,
# tool calls are extracted exclusively from the content.
reasoning_content, content = reasoning_parser.extract_reasoning(output.text, request=request)
if not request.include_reasoning:
reasoning_content = None
else:
reasoning_content = None
content = output.text
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)
and request.tool_choice != "required"
):
message = ChatMessage(role=role, reasoning_content=reasoning_content, content=content)
# if the request uses tools and specified a tool choice
elif request.tool_choice and type(request.tool_choice) is ChatCompletionNamedToolChoiceParam:
tool_call_class = MistralToolCall if isinstance(tokenizer, MistralTokenizer) else ToolCall
message = ChatMessage(
role=role,
reasoning_content=reasoning_content,
content="",
tool_calls=[
tool_call_class(
function=FunctionCall(
name=request.tool_choice.function.name,
arguments=content,
)
)
],
)
elif request.tool_choice and request.tool_choice == "required":
tool_call_class = MistralToolCall if isinstance(tokenizer, MistralTokenizer) else ToolCall
# the fields of FunctionDefinition are a superset of the
# tool call outputs and can be used for parsing
assert content is not None
tool_calls = TypeAdapter(list[FunctionDefinition]).validate_json(content)
tool_call_ids = []
for tool_call in tool_calls:
tool_call_ids.append(
make_tool_call_id(
id_type=self.tool_call_id_type,
func_name=tool_call.name,
idx=history_tool_call_cnt,
)
)
history_tool_call_cnt += 1
message = ChatMessage(
role=role,
content="",
tool_calls=[
tool_call_class(
id=tool_call_ids[i],
function=FunctionCall(
name=tool_call.name,
arguments=json.dumps(tool_call.parameters, ensure_ascii=False),
),
)
for i, tool_call in enumerate(tool_calls)
],
reasoning_content=reasoning_content,
)
# 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, reasoning_content=reasoning_content, content=content)
# 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.exception("Error in tool parser creation.")
return self.create_error_response(e)
tool_call_info = tool_parser.extract_tool_calls(content if content is not None else "", 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,
reasoning_content=reasoning_content,
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.
ret_content = content
# try to use content return from tool parser first,
# tool parser may do some modify for the content.
if tool_call_info.content and len(tool_call_info.content) > 0:
ret_content = tool_call_info.content
message = ChatMessage(
role=role,
reasoning_content=reasoning_content,
content=ret_content,
)
# 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, reasoning_content=reasoning_content, content=content)
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,
token_ids=(as_list(output.token_ids) if request.return_token_ids else None),
)
choices.append(choice_data)
if request.echo:
last_msg_content: str | list[dict[str, str]] = ""
if conversation and "content" in conversation[-1] and conversation[-1].get("role") == role:
last_msg_content = conversation[-1]["content"] or ""
if isinstance(last_msg_content, list):
last_msg_content = "\n".join(msg["text"] for msg in last_msg_content)
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,
)
if self.enable_prompt_tokens_details and final_res.num_cached_tokens:
usage.prompt_tokens_details = PromptTokenUsageInfo(cached_tokens=final_res.num_cached_tokens)
prompt_logprobs = clamp_prompt_logprobs(final_res.prompt_logprobs)
prompt_token_ids = final_res.prompt_token_ids if request.return_token_ids else None
kv_transfer_params = final_res.kv_transfer_params
return choices, usage, prompt_logprobs, prompt_token_ids, kv_transfer_params
def _create_audio_choice(
self, omni_outputs: OmniRequestOutput, role: str, request: ChatCompletionRequest, stream: bool = False
):
choices: list[ChatCompletionResponseChoice] = []
final_res = omni_outputs.request_output
# OMNI: Access multimodal_output from CompletionOutput (outputs[0]), not from RequestOutput
# Reference: examples/offline_inference/qwen3_omni/end2end.py line 421
audio_data = final_res.outputs[0].multimodal_output.get("audio")
if isinstance(audio_data, list):
if stream:
audio_tensor = audio_data[-1]
else:
audio_tensor = torch.cat(audio_data, dim=-1)
else:
audio_tensor = audio_data
audio_tensor = audio_tensor.float().detach().cpu().numpy()
# Ensure audio is 1D (flatten if needed)
if audio_tensor.ndim > 1:
audio_tensor = audio_tensor.flatten()
audio_obj = CreateAudio(
audio_tensor=audio_tensor,
sample_rate=24000,
response_format="wav",
speed=1.0,
stream_format="audio",
base64_encode=True,
)
audio_response: AudioResponse = self.create_audio(audio_obj)
audio_base64 = audio_response.audio_data
# Generate unique ID for the audio
audio_id = f"audio-{uuid.uuid4().hex[:16]}"
# Set expiration time (e.g., 24 hours from now) as Unix timestamp
expires_at = int((datetime.now(timezone.utc) + timedelta(hours=24)).timestamp())
# Create OpenAIChatCompletionAudio object with all required fields
audio_obj = OpenAIChatCompletionAudio(
id=audio_id,
data=audio_base64,
expires_at=expires_at,
transcript="", # Empty transcript if not available
)
for output in final_res.outputs:
if stream:
choice_data = ChatCompletionResponseStreamChoice(
index=output.index,
delta=DeltaMessage(role=role, content=audio_base64),
logprobs=None,
finish_reason="stop",
stop_reason=output.stop_reason,
token_ids=(as_list(output.token_ids) if request.return_token_ids else None),
)
else:
choice_data = ChatCompletionResponseChoice(
index=output.index,
message=ChatMessage(role=role, audio=audio_obj),
logprobs=None,
finish_reason="stop",
stop_reason=None,
)
choices.append(choice_data)
return choices
def _create_image_choice(
self, omni_outputs: OmniRequestOutput, role: str, request: ChatCompletionRequest, stream: bool = False
):
"""Create chat completion response choices for image output.
Converts image tensor or PIL Image output from diffusion models
into base64-encoded image data for API response.
Args:
omni_outputs: Output containing image data from diffusion stage
role: The role for the response message (e.g., "assistant")
Returns:
List of ChatCompletionResponseChoice with image content
"""
from PIL import Image
choices: list[ChatCompletionResponseChoice] = []
final_res = omni_outputs.request_output
# Handle profiling data
stage_durations = omni_outputs.stage_durations
# Handle different image output formats
images = []
# First check omni_outputs.images directly (for diffusion mode via from_diffusion)
if omni_outputs.images:
images = omni_outputs.images
# Fall back to request_output for pipeline mode
# OMNI: Access multimodal_output from CompletionOutput (outputs[0]), not from RequestOutput
elif final_res is not None and final_res.outputs:
completion_output = final_res.outputs[0]
if hasattr(completion_output, "multimodal_output") and completion_output.multimodal_output:
image_data = completion_output.multimodal_output.get("image")
if image_data is not None:
if isinstance(image_data, Image.Image):
images.append(image_data)
elif hasattr(image_data, "cpu"): # Tensor
import numpy as np
# Convert tensor to PIL Image
img_array = image_data.float().detach().cpu().numpy()
# Handle different tensor formats (CHW -> HWC)
if img_array.ndim == 3 and img_array.shape[0] in [1, 3, 4]:
img_array = np.transpose(img_array, (1, 2, 0))
# Normalize to 0-255
if img_array.max() <= 1.0:
img_array = (img_array * 255).astype(np.uint8)
else:
img_array = img_array.astype(np.uint8)
# Handle grayscale
if img_array.ndim == 2:
images.append(Image.fromarray(img_array, mode="L"))
elif img_array.shape[-1] == 1:
images.append(Image.fromarray(img_array.squeeze(-1), mode="L"))
elif img_array.shape[-1] == 3:
images.append(Image.fromarray(img_array, mode="RGB"))
elif img_array.shape[-1] == 4:
images.append(Image.fromarray(img_array, mode="RGBA"))
elif hasattr(final_res, "images") and final_res.images:
images = final_res.images
# Convert images to base64
image_contents = []
for img in images:
with BytesIO() as buffer:
img.save(buffer, format="PNG")
img_bytes = buffer.getvalue()
img_base64 = base64.b64encode(img_bytes).decode("utf-8")
image_contents.append(
{
"type": "image_url",
"image_url": {
"url": f"data:image/png;base64,{img_base64}",
},
"stage_durations": stage_durations,
}
)
# Create message content
if len(image_contents) == 1:
content = image_contents
elif len(image_contents) > 1:
content = image_contents
else:
content = [{"type": "text", "text": "Image generation completed but no images were produced."}]
# Create response choice
# Use model_construct to bypass validation for multimodal content
# (ChatMessage.content only accepts str, but we need list for images)
# Then use object.__setattr__ to directly set the field, bypassing Pydantic's type checking
import warnings as warnings_module
with warnings_module.catch_warnings():
warnings_module.filterwarnings("ignore", category=UserWarning, module="pydantic")
message = ChatMessage.model_construct(role=role)
object.__setattr__(message, "content", content)
# Mark content as set in fields_set to ensure proper serialization
if hasattr(message, "__pydantic_fields_set__"):
message.__pydantic_fields_set__.add("content")
choice_data = ChatCompletionResponseChoice(
index=0,
message=message,
logprobs=None,
finish_reason="stop",
stop_reason=None,
)
choices.append(choice_data)
return choices
# ==================== Diffusion Mode Methods ====================
async def _create_diffusion_chat_completion(
self,
request: ChatCompletionRequest,
raw_request: Request | None = None,
) -> ChatCompletionResponse | ErrorResponse:
"""Generate images via chat completion interface for diffusion models.
Args:
request: Chat completion request
raw_request: Raw FastAPI request object
Returns:
ChatCompletionResponse with generated images or ErrorResponse
"""
try:
request_id = f"chatcmpl-{uuid.uuid4().hex[:16]}"
created_time = int(time.time())
# Convert messages to dict format
messages = []
for msg in request.messages:
if hasattr(msg, "model_dump"):
messages.append(msg.model_dump())
elif isinstance(msg, dict):
messages.append(msg)
else:
messages.append({"role": getattr(msg, "role", "user"), "content": getattr(msg, "content", "")})
# Extract prompt and images from messages
prompt, reference_images = self._extract_diffusion_prompt_and_images(messages)
if not prompt:
return self._create_error_response("No text prompt found in messages")
# Extract generation parameters from extra_body (preferred)
# Reference: text_to_image.py and text_to_video.py for supported parameters
# [NOTE] When sending request via openai client Python library,
# `extra_body` is flattented and merged into the payload's root.
# These extra fields are accessible via `model_extra` property (from Pydantic base class).
# When sending raw request with curl, no flattening happens. Directly read the `extra_body` dict.
extra_body = getattr(request, "extra_body", None)
if not extra_body:
extra_body = request.model_extra or {}
# Parse size if provided (supports "1024x1024" format)
height = extra_body.get("height")
width = extra_body.get("width")
if "size" in extra_body:
try:
size_str = extra_body["size"]
if isinstance(size_str, str) and "x" in size_str.lower():
w, h = size_str.lower().split("x")
width, height = int(w), int(h)
except ValueError:
logger.warning("Invalid size format: %s", extra_body.get("size"))
# Get request parameters from extra_body.
# Avoid hardcoded defaults here — let each pipeline's forward()
# method apply its own model-specific default when the user does
# not provide a value.
num_inference_steps = extra_body.get("num_inference_steps")
guidance_scale = extra_body.get("guidance_scale")
true_cfg_scale = extra_body.get("true_cfg_scale") or extra_body.get("cfg_scale")
seed = extra_body.get("seed")
negative_prompt = extra_body.get("negative_prompt")
num_outputs_per_prompt = extra_body.get("num_outputs_per_prompt", 1)
# Text-to-video parameters (ref: text_to_video.py)
num_frames = extra_body.get("num_frames")
guidance_scale_2 = extra_body.get("guidance_scale_2")
lora_body = extra_body.get("lora")
# Qwen-Image-Layered parameters
layers = extra_body.get("layers")
resolution = extra_body.get("resolution")
logger.info(
"Diffusion chat request %s: prompt=%r, ref_images=%d, params=%s",
request_id,
prompt[:50] + "..." if len(prompt) > 50 else prompt,
len(reference_images),
{k: v for k, v in extra_body.items() if v is not None},
)
# Decode reference images if provided
pil_images: list[Image.Image] = []
for img_b64 in reference_images:
try:
img_bytes = base64.b64decode(img_b64)
pil_images.append(Image.open(BytesIO(img_bytes)))
except Exception as e:
logger.warning("Failed to decode reference image: %s", e)
# Build generation kwargs
gen_prompt: OmniTextPrompt = {
"prompt": prompt,
"negative_prompt": negative_prompt,
}
gen_params = OmniDiffusionSamplingParams(
height=height,
width=width,
num_outputs_per_prompt=num_outputs_per_prompt,
seed=seed,
)
# Only override defaults when the user explicitly provides values
if num_inference_steps is not None:
gen_params.num_inference_steps = num_inference_steps
if guidance_scale is not None:
gen_params.guidance_scale = guidance_scale
if true_cfg_scale is not None:
gen_params.true_cfg_scale = true_cfg_scale
if num_frames is not None:
gen_params.num_frames = num_frames
if guidance_scale_2 is not None:
gen_params.guidance_scale_2 = guidance_scale_2
if layers is not None:
gen_params.layers = layers
if resolution is not None:
gen_params.resolution = resolution
# Parse per-request LoRA (works for both AsyncOmniDiffusion and AsyncOmni).
if lora_body and isinstance(lora_body, dict):
try:
lora_req, lora_scale = parse_lora_request(lora_body)
if lora_req is not None:
gen_params.lora_request = lora_req
if lora_scale is not None:
gen_params.lora_scale = lora_scale
except Exception as e: # pragma: no cover - safeguard
logger.warning("Failed to parse LoRA request: %s", e)
# Add reference image if provided
if pil_images:
if len(pil_images) == 1:
gen_prompt["multi_modal_data"] = {}
gen_prompt["multi_modal_data"]["image"] = pil_images[0]
else:
od_config = getattr(self._diffusion_engine, "od_config", None)
supports_multimodal_inputs = getattr(od_config, "supports_multimodal_inputs", False)
if od_config is None:
# TODO: entry is asyncOmni. We hack the od config here.
supports_multimodal_inputs = True
if supports_multimodal_inputs:
gen_prompt["multi_modal_data"] = {}
gen_prompt["multi_modal_data"]["image"] = pil_images
else:
return self._create_error_response(
"Multiple input images are not supported by the current diffusion model. "
"For multi-image editing, start the server with Qwen-Image-Edit-2509 "
"and send multiple images in the user message content.",
status_code=400,
)
# Generate image
# Handle both AsyncOmniDiffusion (returns OmniRequestOutput) and AsyncOmni (returns AsyncGenerator)
if isinstance(self._diffusion_engine, AsyncOmni):
diffusion_engine = cast(AsyncOmni, self._diffusion_engine)
result = None
async for output in diffusion_engine.generate(
prompt=gen_prompt,
sampling_params_list=[gen_params], # Pass as single-stage params
request_id=request_id,
):
result = output
if result is None:
return self._create_error_response("No output generated from AsyncOmni")
else:
# AsyncOmniDiffusion: direct call
diffusion_engine = cast(AsyncOmniDiffusion, self._diffusion_engine)
result = await diffusion_engine.generate(
prompt=gen_prompt,
sampling_params=gen_params,
request_id=request_id,
)
# Extract images from result
# Handle nested OmniRequestOutput structure where images might be in request_output
images = getattr(result.request_output, "images", [])
stage_durations = result.stage_durations
# Convert images to base64 content
image_contents: list[dict[str, Any]] = []
flat_images = []
for item in images:
if isinstance(item, list):
flat_images.extend(item)
else:
flat_images.append(item)
for img in flat_images:
with BytesIO() as buffer:
img.save(buffer, format="PNG")
img_base64 = base64.b64encode(buffer.getvalue()).decode("utf-8")
image_contents.append(
{
"type": "image_url",
"image_url": {
"url": f"data:image/png;base64,{img_base64}",
},
"stage_durations": stage_durations,
}
)
# Build response
if not image_contents:
content = "Image generation completed but no images were produced."
else:
content = image_contents
# Use model_construct to bypass validation for multimodal content
# (ChatMessage.content only accepts str, but we need list for images)
# Then use object.__setattr__ to directly set the field, bypassing Pydantic's type checking
import warnings as warnings_module
with warnings_module.catch_warnings():
warnings_module.filterwarnings("ignore", category=UserWarning, module="pydantic")
message = ChatMessage.model_construct(role="assistant")
object.__setattr__(message, "content", content)
# Mark content as set in fields_set to ensure proper serialization
if hasattr(message, "__pydantic_fields_set__"):
message.__pydantic_fields_set__.add("content")
choice = ChatCompletionResponseChoice.model_construct(
index=0,
message=message,
finish_reason="stop",
logprobs=None,
stop_reason=None,
)
response = ChatCompletionResponse(
id=request_id,
created=created_time,
model=self._diffusion_model_name,
choices=[choice],
usage=UsageInfo(
prompt_tokens=len(prompt.split()),
completion_tokens=1,
total_tokens=len(prompt.split()) + 1,
),
)
logger.info(
"Diffusion chat completed for request %s: %d images",
request_id,
len(images),
)
return response
except Exception as e:
logger.exception("Diffusion chat completion failed: %s", e)
return self._create_error_response(
f"Image generation failed: {str(e)}",
status_code=500,
)
def _extract_diffusion_prompt_and_images(
self,
messages: list[dict[str, Any]],
) -> tuple[str, list[str]]:
"""Extract text prompt and base64 images from chat messages.
Args:
messages: List of chat messages
Returns:
Tuple of (prompt_text, list_of_base64_images)
"""
prompt_parts: list[str] = []
images: list[str] = []
for message in messages:
role = message.get("role", "")
if role != "user":
continue
content = message.get("content", "")
# String content
if isinstance(content, str):
prompt_parts.append(content)
continue
# List of content items
if isinstance(content, list):
for item in content:
if isinstance(item, str):
prompt_parts.append(item)
elif isinstance(item, dict):
# Handle {"type": "text", "text": "..."} format
if item.get("type") == "text":
prompt_parts.append(item.get("text", ""))
# Handle {"text": "..."} format
elif "text" in item and "type" not in item:
prompt_parts.append(item["text"])
# Handle {"type": "image_url", "image_url": {"url": "..."}}
elif item.get("type") == "image_url":
url = item.get("image_url", {}).get("url", "")
if url.startswith("data:image"):
try:
_, b64_data = url.split(",", 1)
images.append(b64_data)
except ValueError:
logger.warning("Invalid data URL format")
# Handle {"image": "base64..."} format
elif "image" in item:
images.append(item["image"])
prompt = " ".join(prompt_parts).strip()
return prompt, images
def _create_error_response(
self,
message: str,
err_type: str = "BadRequestError",
status_code: int = 400,
) -> ErrorResponse:
"""Create an error response following OpenAI error format."""
return ErrorResponse(
error=ErrorInfo(
message=message,
type=err_type,
code=status_code,
)
)