Files
sglang/python/sglang/srt/entrypoints/openai/serving_chat.py

1220 lines
49 KiB
Python

from __future__ import annotations
import copy
import json
import logging
import time
import uuid
from typing import TYPE_CHECKING, Any, AsyncGenerator, Dict, List, Optional, Union
from fastapi import Request
from fastapi.responses import ORJSONResponse, StreamingResponse
from jsonschema import Draft202012Validator, SchemaError
from sglang.srt.entrypoints.openai.protocol import (
ChatCompletionRequest,
ChatCompletionResponse,
ChatCompletionResponseChoice,
ChatCompletionResponseStreamChoice,
ChatCompletionStreamResponse,
ChatCompletionTokenLogprob,
ChatMessage,
ChoiceLogprobs,
DeltaMessage,
ErrorResponse,
FunctionResponse,
LogProbs,
MessageProcessingResult,
ToolCall,
ToolCallProcessingResult,
ToolChoice,
TopLogprob,
)
from sglang.srt.entrypoints.openai.serving_base import OpenAIServingBase
from sglang.srt.entrypoints.openai.usage_processor import UsageProcessor
from sglang.srt.entrypoints.openai.utils import (
process_hidden_states_from_ret,
to_openai_style_logprobs,
)
from sglang.srt.function_call.core_types import ToolCallItem
from sglang.srt.function_call.function_call_parser import FunctionCallParser
from sglang.srt.function_call.json_array_parser import JsonArrayParser
from sglang.srt.function_call.utils import get_json_schema_constraint
from sglang.srt.managers.io_struct import GenerateReqInput
from sglang.srt.parser.conversation import generate_chat_conv
from sglang.srt.parser.jinja_template_utils import process_content_for_template_format
from sglang.srt.parser.reasoning_parser import ReasoningParser
from sglang.utils import convert_json_schema_to_str
if TYPE_CHECKING:
from sglang.srt.managers.template_manager import TemplateManager
from sglang.srt.managers.tokenizer_manager import TokenizerManager
logger = logging.getLogger(__name__)
class OpenAIServingChat(OpenAIServingBase):
"""Handler for /v1/chat/completions requests"""
def __init__(
self,
tokenizer_manager: TokenizerManager,
template_manager: TemplateManager,
):
super().__init__(tokenizer_manager)
self.template_manager = template_manager
self.tool_call_parser = self.tokenizer_manager.server_args.tool_call_parser
def _request_id_prefix(self) -> str:
return "chatcmpl-"
def _validate_request(self, request: ChatCompletionRequest) -> Optional[str]:
"""Validate that the input is valid."""
if not request.messages:
return "Messages cannot be empty."
if (
isinstance(request.tool_choice, str)
and request.tool_choice.lower() == "required"
and not request.tools
):
return "Tools cannot be empty if tool choice is set to required."
if request.tool_choice is not None and not isinstance(request.tool_choice, str):
if not request.tools:
return "Tools cannot be empty if tool choice is set to a specific tool."
tool_name = request.tool_choice.function.name
tool_exists = any(tool.function.name == tool_name for tool in request.tools)
if not tool_exists:
return f"Tool '{tool_name}' not found in tools list."
# Validate tool definitions
for i, tool in enumerate(request.tools or []):
if tool.function.parameters is None:
continue
try:
Draft202012Validator.check_schema(tool.function.parameters)
except SchemaError as e:
return f"Tool {i} function has invalid 'parameters' schema: {str(e)}"
max_output_tokens = request.max_completion_tokens or request.max_tokens
server_context_length = self.tokenizer_manager.server_args.context_length
if (
max_output_tokens
and server_context_length
and max_output_tokens > server_context_length
):
return (
f"max_completion_tokens is too large: {max_output_tokens}."
f"This model supports at most {server_context_length} completion tokens."
)
if request.response_format and request.response_format.type == "json_schema":
schema = getattr(request.response_format.json_schema, "schema_", None)
if schema is None:
return "schema_ is required for json_schema response format request."
return None
def _convert_to_internal_request(
self,
request: ChatCompletionRequest,
raw_request: Request = None,
) -> tuple[GenerateReqInput, ChatCompletionRequest]:
reasoning_effort = (
request.chat_template_kwargs.pop("reasoning_effort", None)
if request.chat_template_kwargs
else None
)
if reasoning_effort is not None:
request.reasoning_effort = reasoning_effort
"""Convert OpenAI chat completion request to internal format"""
is_multimodal = self.tokenizer_manager.model_config.is_multimodal
# Process messages and apply chat template
processed_messages = self._process_messages(request, is_multimodal)
# Build sampling parameters
sampling_params = self._build_sampling_params(
request,
processed_messages.stop,
processed_messages.tool_call_constraint,
)
# Handle single vs multiple requests
if is_multimodal:
prompt_kwargs = {"text": processed_messages.prompt}
else:
if isinstance(processed_messages.prompt_ids, str):
prompt_kwargs = {"text": processed_messages.prompt_ids}
else:
prompt_kwargs = {"input_ids": processed_messages.prompt_ids}
# Extract custom labels from raw request headers
custom_labels = self.extract_custom_labels(raw_request)
adapted_request = GenerateReqInput(
**prompt_kwargs,
image_data=processed_messages.image_data,
video_data=processed_messages.video_data,
audio_data=processed_messages.audio_data,
sampling_params=sampling_params,
return_logprob=request.logprobs,
logprob_start_len=-1,
top_logprobs_num=request.top_logprobs or 0,
stream=request.stream,
return_text_in_logprobs=True,
modalities=processed_messages.modalities,
lora_path=request.lora_path,
bootstrap_host=request.bootstrap_host,
bootstrap_port=request.bootstrap_port,
bootstrap_room=request.bootstrap_room,
return_hidden_states=request.return_hidden_states,
rid=request.rid,
extra_key=self._compute_extra_key(request),
priority=request.priority,
custom_labels=custom_labels,
)
return adapted_request, request
def _process_messages(
self, request: ChatCompletionRequest, is_multimodal: bool
) -> MessageProcessingResult:
"""Process chat messages and apply chat template"""
is_gpt_oss = (
hasattr(self.tokenizer_manager.model_config, "hf_config")
and hasattr(self.tokenizer_manager.model_config.hf_config, "model_type")
and self.tokenizer_manager.model_config.hf_config.model_type == "gpt_oss"
)
# GptOss model needs to keep special tokens for harmony parsing
if is_gpt_oss:
request.skip_special_tokens = False
tool_call_constraint = None
# Apply chat template and its stop strings
tools = None
if request.tools and request.tool_choice != "none":
request.skip_special_tokens = False
if not isinstance(request.tool_choice, str):
tools = [
item.function.model_dump()
for item in request.tools
if item.function.name == request.tool_choice.function.name
]
else:
tools = [item.function.model_dump() for item in request.tools]
if self.tool_call_parser:
parser = FunctionCallParser(request.tools, self.tool_call_parser)
tool_call_constraint = parser.get_structure_constraint(
request.tool_choice
)
# Handle JSON schema constraint directly for required or named tool choice
if request.tool_choice == "required" or isinstance(
request.tool_choice, ToolChoice
):
json_schema = get_json_schema_constraint(
request.tools, request.tool_choice
)
tool_call_constraint = ("json_schema", json_schema)
# Use chat template
if self.template_manager.chat_template_name is None:
result = self._apply_jinja_template(request, tools, is_multimodal)
else:
result = self._apply_conversation_template(request, is_multimodal)
result.tool_call_constraint = tool_call_constraint
return result
def _apply_jinja_template(
self,
request: ChatCompletionRequest,
tools: Optional[List[Dict]],
is_multimodal: bool,
) -> MessageProcessingResult:
"""Apply Jinja chat template"""
prompt = ""
prompt_ids = []
openai_compatible_messages = []
image_data = []
video_data = []
audio_data = []
modalities = []
template_content_format = self.template_manager.jinja_template_content_format
for message in request.messages:
if message.content is None:
message.content = ""
msg_dict = message.model_dump()
# Process content based on detected template format
processed_msg = process_content_for_template_format(
msg_dict,
template_content_format,
image_data,
video_data,
audio_data,
modalities,
)
# per the Transformers docs & maintainers, tool call arguments in
# assistant-role messages with tool_calls need to be dicts not JSON str -
# this is how tool-use chat templates will expect them moving forwards
# so, for messages that have tool_calls, parse the string (which we get
# from openAI format) to dict
if (
processed_msg["role"] == "assistant"
and "tool_calls" in processed_msg
and isinstance(processed_msg["tool_calls"], list)
):
for item in processed_msg["tool_calls"]:
if "arguments" in item["function"] and isinstance(
item["function"]["arguments"], str
):
item["function"]["arguments"] = json.loads(
item["function"]["arguments"]
)
openai_compatible_messages.append(processed_msg)
# Handle assistant prefix for continue_final_message
assistant_prefix = None
if (
openai_compatible_messages
and openai_compatible_messages[-1]["role"] == "assistant"
):
if request.continue_final_message:
assistant_prefix = openai_compatible_messages[-1]["content"]
openai_compatible_messages = openai_compatible_messages[:-1]
try:
prompt_ids = self.tokenizer_manager.tokenizer.apply_chat_template(
openai_compatible_messages,
tokenize=True,
add_generation_prompt=True,
tools=tools,
reasoning_effort=request.reasoning_effort,
**(
request.chat_template_kwargs if request.chat_template_kwargs else {}
),
)
except Exception:
# This except branch will be triggered when the chosen model
# has a different tools input format that is not compatible
# with openAI's apply_chat_template tool_call format, like Mistral.
tools = (
[t if "function" in t else {"function": t} for t in tools]
if tools
else None
)
prompt_ids = self.tokenizer_manager.tokenizer.apply_chat_template(
openai_compatible_messages,
tokenize=True,
add_generation_prompt=True,
tools=tools,
reasoning_effort=request.reasoning_effort,
**(
request.chat_template_kwargs if request.chat_template_kwargs else {}
),
)
if assistant_prefix:
encoded = self.tokenizer_manager.tokenizer.encode(assistant_prefix)
if encoded and encoded[0] == self.tokenizer_manager.tokenizer.bos_token_id:
encoded = encoded[1:]
prompt_ids += encoded
if is_multimodal:
prompt = self.tokenizer_manager.tokenizer.decode(prompt_ids)
stop = request.stop
image_data = image_data if image_data else None
audio_data = audio_data if audio_data else None
video_data = video_data if video_data else None
modalities = modalities if modalities else []
return MessageProcessingResult(
prompt=prompt,
prompt_ids=prompt_ids,
image_data=image_data,
video_data=video_data,
audio_data=audio_data,
modalities=modalities,
stop=stop,
)
def _apply_conversation_template(
self,
request: ChatCompletionRequest,
is_multimodal: bool,
) -> MessageProcessingResult:
"""Apply conversation template"""
prompt = ""
prompt_ids = []
conv = generate_chat_conv(request, self.template_manager.chat_template_name)
# If we should continue the final assistant message, adjust the conversation.
if (
request.continue_final_message
and request.messages
and request.messages[-1].role == "assistant"
):
# Remove the auto-added blank assistant turn, if present.
if conv.messages and conv.messages[-1][1] is None:
conv.messages.pop()
# Rebuild the prompt from the conversation.
prompt = conv.get_prompt()
# Strip trailing stop tokens or separators that indicate end-of-assistant.
if isinstance(conv.stop_str, list):
for stop_token in conv.stop_str:
if prompt.endswith(stop_token):
prompt = prompt[: -len(stop_token)]
elif isinstance(conv.stop_str, str) and prompt.endswith(conv.stop_str):
prompt = prompt[: -len(conv.stop_str)]
if conv.sep and prompt.endswith(conv.sep):
prompt = prompt[: -len(conv.sep)]
if getattr(conv, "sep2", None) and prompt.endswith(conv.sep2):
prompt = prompt[: -len(conv.sep2)]
else:
prompt = conv.get_prompt()
if self._get_enable_thinking_from_request(request):
prompt += "<think>" # Note(Xinyuan): hard code thinking token
image_data = conv.image_data if conv.image_data else None
video_data = conv.video_data if conv.video_data else None
audio_data = conv.audio_data if conv.audio_data else None
modalities = conv.modalities if conv.modalities else []
stop = copy.copy(conv.stop_str or [] if not request.ignore_eos else [])
if request.stop:
if isinstance(request.stop, str):
stop.append(request.stop)
else:
stop.extend(request.stop)
if not is_multimodal:
prompt_ids = self.tokenizer_manager.tokenizer.encode(prompt)
return MessageProcessingResult(
prompt=prompt,
prompt_ids=prompt_ids,
image_data=image_data,
video_data=video_data,
audio_data=audio_data,
modalities=modalities,
stop=stop,
)
def _build_sampling_params(
self,
request: ChatCompletionRequest,
stop: List[str],
tool_call_constraint: Optional[Any],
) -> Dict[str, Any]:
"""Build sampling parameters for the request"""
sampling_params = {
"temperature": request.temperature,
"max_new_tokens": request.max_tokens or request.max_completion_tokens,
"min_new_tokens": request.min_tokens,
"stop": stop,
"stop_token_ids": request.stop_token_ids,
"top_p": request.top_p,
"top_k": request.top_k,
"min_p": request.min_p,
"presence_penalty": request.presence_penalty,
"frequency_penalty": request.frequency_penalty,
"repetition_penalty": request.repetition_penalty,
"regex": request.regex,
"ebnf": request.ebnf,
"n": request.n,
"no_stop_trim": request.no_stop_trim,
"ignore_eos": request.ignore_eos,
"skip_special_tokens": request.skip_special_tokens,
"logit_bias": request.logit_bias,
}
if request.response_format and request.response_format.type == "json_schema":
sampling_params["json_schema"] = convert_json_schema_to_str(
request.response_format.json_schema.schema_
)
elif request.response_format and request.response_format.type == "json_object":
sampling_params["json_schema"] = '{"type": "object"}'
elif (
request.response_format and request.response_format.type == "structural_tag"
):
sampling_params["structural_tag"] = convert_json_schema_to_str(
request.response_format.model_dump(by_alias=True)
)
# Check if there are already existing output constraints
has_existing_constraints = (
sampling_params.get("regex")
or sampling_params.get("ebnf")
or sampling_params.get("structural_tag")
or sampling_params.get("json_schema")
)
if tool_call_constraint and has_existing_constraints:
logger.warning("Constrained decoding is not compatible with tool calls.")
elif tool_call_constraint:
constraint_type, constraint_value = tool_call_constraint
if constraint_type == "structural_tag":
sampling_params[constraint_type] = convert_json_schema_to_str(
constraint_value.model_dump(by_alias=True)
)
elif constraint_type == "json_schema":
sampling_params[constraint_type] = convert_json_schema_to_str(
constraint_value
)
else:
sampling_params[constraint_type] = constraint_value
return sampling_params
async def _handle_streaming_request(
self,
adapted_request: GenerateReqInput,
request: ChatCompletionRequest,
raw_request: Request,
) -> StreamingResponse:
"""Handle streaming chat completion request"""
return StreamingResponse(
self._generate_chat_stream(adapted_request, request, raw_request),
media_type="text/event-stream",
background=self.tokenizer_manager.create_abort_task(adapted_request),
)
async def _generate_chat_stream(
self,
adapted_request: GenerateReqInput,
request: ChatCompletionRequest,
raw_request: Request,
) -> AsyncGenerator[str, None]:
"""Generate streaming chat completion response"""
# Parsers for tool calls and reasoning
parser_dict = {}
reasoning_parser_dict = {}
# State tracking for streaming
is_firsts = {}
stream_buffers = {}
n_prev_tokens = {}
has_tool_calls = {}
finish_reasons = {}
# Usage tracking
prompt_tokens = {}
completion_tokens = {}
cached_tokens = {}
hidden_states = {}
try:
async for content in self.tokenizer_manager.generate_request(
adapted_request, raw_request
):
index = content.get("index", 0)
prompt_tokens[index] = content["meta_info"]["prompt_tokens"]
completion_tokens[index] = content["meta_info"]["completion_tokens"]
cached_tokens[index] = content["meta_info"].get("cached_tokens", 0)
hidden_states[index] = content["meta_info"].get("hidden_states", None)
# Handle logprobs
choice_logprobs = None
if request.logprobs:
choice_logprobs = self._process_streaming_logprobs(
content, n_prev_tokens.get(index, 0)
)
n_prev_tokens[index] = len(
content["meta_info"]["output_token_logprobs"]
)
finish_reason = content["meta_info"]["finish_reason"]
finish_reason_type = finish_reason["type"] if finish_reason else None
# Track finish_reason for each index
if finish_reason_type:
finish_reasons[index] = finish_reason
# First chunk with role
if is_firsts.get(index, True):
is_firsts[index] = False
delta = DeltaMessage(role="assistant", content="")
choice_data = ChatCompletionResponseStreamChoice(
index=index,
delta=delta,
finish_reason=None,
logprobs=None,
)
chunk = ChatCompletionStreamResponse(
id=content["meta_info"]["id"],
created=int(time.time()),
choices=[choice_data],
model=request.model,
)
yield f"data: {chunk.model_dump_json()}\n\n"
stream_buffer = stream_buffers.get(index, "")
delta = content["text"][len(stream_buffer) :]
stream_buffers[index] = stream_buffer + delta
# Handle reasoning content
if (
self.tokenizer_manager.server_args.reasoning_parser
and request.separate_reasoning
):
reasoning_text, delta = self._process_reasoning_stream(
index, delta, reasoning_parser_dict, content, request
)
if reasoning_text:
choice_data = ChatCompletionResponseStreamChoice(
index=index,
delta=DeltaMessage(reasoning_content=reasoning_text),
finish_reason=None,
)
chunk = ChatCompletionStreamResponse(
id=content["meta_info"]["id"],
created=int(time.time()),
choices=[choice_data],
model=request.model,
)
yield f"data: {chunk.model_dump_json()}\n\n"
# Handle tool calls
if (
request.tool_choice != "none"
and request.tools
and self.tool_call_parser
):
async for chunk in self._process_tool_call_stream(
index,
delta,
parser_dict,
content,
request,
has_tool_calls,
):
if chunk:
yield chunk
# Send any remaining tool call arguments when generation finishes
if finish_reason_type is not None and index in parser_dict:
parser = parser_dict[index]
remaining_chunk = self._check_for_unstreamed_tool_args(
parser, content, request, index
)
if remaining_chunk:
yield remaining_chunk
else:
# Regular content
if delta:
choice_data = ChatCompletionResponseStreamChoice(
index=index,
delta=DeltaMessage(content=delta),
finish_reason=None,
matched_stop=None,
logprobs=choice_logprobs,
)
chunk = ChatCompletionStreamResponse(
id=content["meta_info"]["id"],
created=int(time.time()),
choices=[choice_data],
model=request.model,
)
yield f"data: {chunk.model_dump_json()}\n\n"
# Send finish_reason chunks for each index that completed
for idx, finish_reason_data in finish_reasons.items():
finish_reason_type = finish_reason_data["type"]
# Change finish_reason to "tool_calls" if we had tool calls and stopped naturally
final_finish_reason = finish_reason_type
if has_tool_calls.get(idx, False) and finish_reason_type == "stop":
final_finish_reason = "tool_calls"
finish_reason_chunk = ChatCompletionStreamResponse(
id=content["meta_info"][
"id"
], # NOTE: openai uses the same chatcmpl-id for all indices
created=int(time.time()),
choices=[
ChatCompletionResponseStreamChoice(
index=idx,
delta=DeltaMessage(),
finish_reason=final_finish_reason,
matched_stop=(
finish_reason_data["matched"]
if "matched" in finish_reason_data
else None
),
)
],
model=request.model,
usage=None,
)
yield f"data: {finish_reason_chunk.model_dump_json()}\n\n"
# Send hidden states if requested
if request.return_hidden_states and hidden_states:
for index, choice_hidden_states in hidden_states.items():
if choice_hidden_states:
last_token_hidden_states = (
choice_hidden_states[-1]
if len(choice_hidden_states) > 1
else []
)
hidden_states_chunk = ChatCompletionStreamResponse(
id=content["meta_info"]["id"],
created=int(time.time()),
choices=[
ChatCompletionResponseStreamChoice(
index=index,
delta=DeltaMessage(
hidden_states=last_token_hidden_states
),
finish_reason=None, # Hidden states don't need finish_reason
)
],
model=request.model,
)
yield f"data: {hidden_states_chunk.model_dump_json()}\n\n"
# Additional usage chunk
if request.stream_options and request.stream_options.include_usage:
usage = UsageProcessor.calculate_streaming_usage(
prompt_tokens,
completion_tokens,
cached_tokens,
n_choices=request.n,
enable_cache_report=self.tokenizer_manager.server_args.enable_cache_report,
)
usage_chunk = ChatCompletionStreamResponse(
id=content["meta_info"]["id"],
created=int(time.time()),
choices=[], # Empty choices array as per OpenAI spec
model=request.model,
usage=usage,
)
yield f"data: {usage_chunk.model_dump_json()}\n\n"
except ValueError as e:
error = self.create_streaming_error_response(str(e))
yield f"data: {error}\n\n"
yield "data: [DONE]\n\n"
async def _handle_non_streaming_request(
self,
adapted_request: GenerateReqInput,
request: ChatCompletionRequest,
raw_request: Request,
) -> Union[ChatCompletionResponse, ErrorResponse, ORJSONResponse]:
"""Handle non-streaming chat completion request"""
try:
ret = await self.tokenizer_manager.generate_request(
adapted_request, raw_request
).__anext__()
except ValueError as e:
return self.create_error_response(str(e))
if not isinstance(ret, list):
ret = [ret]
response = self._build_chat_response(
request,
ret,
int(time.time()),
)
return response
def _build_chat_response(
self,
request: ChatCompletionRequest,
ret: List[Dict[str, Any]],
created: int,
) -> Union[ChatCompletionResponse, ORJSONResponse]:
"""Build chat completion response from generation results"""
choices = []
for idx, ret_item in enumerate(ret):
# Process logprobs
choice_logprobs = None
if request.logprobs:
choice_logprobs = self._process_response_logprobs(ret_item)
# Handle hidden states
hidden_states = process_hidden_states_from_ret(ret_item, request)
finish_reason = ret_item["meta_info"]["finish_reason"]
text = ret_item["text"]
# Handle reasoning content
reasoning_text = None
reasoning_parser = self.tokenizer_manager.server_args.reasoning_parser
if reasoning_parser and request.separate_reasoning:
is_force_reasoning = (
self.template_manager.force_reasoning
or self._get_enable_thinking_from_request(request)
)
try:
parser = ReasoningParser(
model_type=reasoning_parser,
stream_reasoning=False,
force_reasoning=is_force_reasoning,
)
reasoning_text, text = parser.parse_non_stream(text)
except Exception as e:
logger.error(f"Reasoning parsing error: {e}")
return self.create_error_response(
"Failed to parse reasoning content",
err_type="InternalServerError",
status_code=500,
)
# Handle tool calls
tool_calls = None
if (
request.tool_choice != "none"
and request.tools
and self.tool_call_parser
):
history_tool_calls_cnt = self._get_history_tool_calls_cnt(request)
tool_calls, text, finish_reason = self._process_tool_calls(
text,
request.tools,
finish_reason,
request.tool_choice,
history_tool_calls_cnt,
)
choice_data = ChatCompletionResponseChoice(
index=idx,
message=ChatMessage(
role="assistant",
content=text if text else None,
tool_calls=tool_calls,
reasoning_content=reasoning_text if reasoning_text else None,
),
logprobs=choice_logprobs,
finish_reason=finish_reason["type"] if finish_reason else None,
matched_stop=(
finish_reason["matched"]
if finish_reason and "matched" in finish_reason
else None
),
hidden_states=hidden_states,
)
choices.append(choice_data)
# Calculate usage
usage = UsageProcessor.calculate_response_usage(
ret,
n_choices=request.n,
enable_cache_report=self.tokenizer_manager.server_args.enable_cache_report,
)
return ChatCompletionResponse(
id=ret[0]["meta_info"]["id"],
created=created,
model=request.model,
choices=choices,
usage=usage,
metadata={"weight_version": ret[0]["meta_info"]["weight_version"]},
)
def _process_logprobs_tokens(
self, logprobs: LogProbs, use_token_index: bool = False
) -> List[ChatCompletionTokenLogprob]:
"""Common helper to process logprobs tokens for both streaming and non-streaming
Args:
logprobs: LogProbs data from model
use_token_index: True for non-streaming (use token_idx), False for streaming (use index 0)
"""
token_logprobs = []
for token_idx, (token, logprob) in enumerate(
zip(logprobs.tokens, logprobs.token_logprobs)
):
token_bytes = list(token.encode("utf-8"))
top_logprobs = []
if logprobs.top_logprobs:
# - Non-streaming (use_token_index=True): uses token_idx for full data
# - Streaming (use_token_index=False): uses index 0 for pre-sliced data
top_logprobs_idx = token_idx if use_token_index else 0
for top_token, top_logprob in logprobs.top_logprobs[
top_logprobs_idx
].items():
top_token_bytes = list(top_token.encode("utf-8"))
top_logprobs.append(
TopLogprob(
token=top_token,
bytes=top_token_bytes,
logprob=top_logprob,
)
)
token_logprobs.append(
ChatCompletionTokenLogprob(
token=token,
bytes=token_bytes,
logprob=logprob,
top_logprobs=top_logprobs,
)
)
return token_logprobs
def _process_response_logprobs(self, ret_item: Dict[str, Any]) -> ChoiceLogprobs:
"""Process logprobs for non-streaming response"""
logprobs = to_openai_style_logprobs(
output_token_logprobs=ret_item["meta_info"]["output_token_logprobs"],
output_top_logprobs=ret_item["meta_info"].get("output_top_logprobs", None),
)
token_logprobs = self._process_logprobs_tokens(logprobs, use_token_index=True)
return ChoiceLogprobs(content=token_logprobs)
def _process_tool_call_id(
self,
call_item: ToolCallItem,
history_tool_calls_cnt: int,
) -> str:
"""Process for generating a new and unique `tool_call_id`"""
if self.tool_call_parser != "kimi_k2":
# A simple uuid is sufficient for all models except for Kimi-K2.
tool_call_id = f"call_{uuid.uuid4().hex[:24]}"
return tool_call_id
else:
# Align with Kimi-K2 format: functions.{name}:{index}
# Kimi-K2 allows multiple tool_calls in one message; SGLang sets call_item.tool_index to the *local* position inside that message.
# Therefore, the index must be corrected by using `history_tool_calls_cnt + call_item.tool_index` to ensure globally unique and properly ordered.
tool_call_id = f"functions.{call_item.name}:{history_tool_calls_cnt+call_item.tool_index}"
logger.debug(
f"Process tool call idx, parser: {self.tool_call_parser}, tool_call_id: {tool_call_id}, history_cnt: {history_tool_calls_cnt}"
)
return tool_call_id
def _process_tool_calls(
self,
text: str,
tools: List[Any],
finish_reason: Dict[str, Any],
tool_choice: Optional[Union[str, ToolChoice]] = None,
history_tool_calls_cnt: int = 0,
) -> ToolCallProcessingResult:
"""Process tool calls in the response"""
# Handle required or named tool choice
if tool_choice == "required" or (
isinstance(tool_choice, ToolChoice) and tool_choice.type == "function"
):
# Set finish reason to tool_calls since we're processing tool calls
if finish_reason["type"] == "stop":
finish_reason["type"] = "tool_calls"
finish_reason["matched"] = None
try:
# For required tool choice, we expect a JSON array of tool calls
tool_call_data = json.loads(text)
tool_calls = []
for i, tool in enumerate(tool_call_data):
# Create a ToolCallItem from the JSON data
call_info = ToolCallItem(
tool_index=i, # Use the loop index as tool_index
name=tool["name"],
parameters=json.dumps(tool["parameters"], ensure_ascii=False),
)
tool_id = self._process_tool_call_id(
call_info, history_tool_calls_cnt
)
tool_calls.append(
ToolCall(
id=tool_id,
index=i,
function=FunctionResponse(
name=tool["name"],
arguments=json.dumps(
tool["parameters"], ensure_ascii=False
),
),
)
)
return ToolCallProcessingResult(tool_calls, "", finish_reason)
except json.JSONDecodeError as e:
logger.error(f"Tool call parsing error: {e}")
return ToolCallProcessingResult(None, text, finish_reason)
# Use parser since output is not constrained by JSON schema
parser = FunctionCallParser(tools, self.tool_call_parser)
if parser.has_tool_call(text):
if finish_reason["type"] == "stop":
finish_reason["type"] = "tool_calls"
finish_reason["matched"] = None
try:
text, call_info_list = parser.parse_non_stream(text)
tool_calls = []
for call_info in call_info_list:
tool_id = self._process_tool_call_id(
call_info, history_tool_calls_cnt
)
tool_calls.append(
ToolCall(
id=tool_id,
index=getattr(call_info, "tool_index", None),
function=FunctionResponse(
name=call_info.name, arguments=call_info.parameters
),
)
)
return ToolCallProcessingResult(tool_calls, text, finish_reason)
except Exception as e:
logger.error(f"Tool call parsing error: {e}")
# Return error but don't fail the whole request
return ToolCallProcessingResult(None, text, finish_reason)
return ToolCallProcessingResult(None, text, finish_reason)
def _process_streaming_logprobs(
self, content: Dict[str, Any], n_prev_token: int
) -> ChoiceLogprobs:
"""Process logprobs for streaming response"""
logprobs = to_openai_style_logprobs(
output_token_logprobs=content["meta_info"]["output_token_logprobs"][
n_prev_token:
],
output_top_logprobs=content["meta_info"].get("output_top_logprobs", [])[
n_prev_token:
],
)
token_logprobs = self._process_logprobs_tokens(logprobs, use_token_index=False)
return ChoiceLogprobs(content=token_logprobs)
def _process_reasoning_stream(
self,
index: int,
delta: str,
reasoning_parser_dict: Dict[int, ReasoningParser],
content: Dict[str, Any],
request: ChatCompletionRequest,
) -> tuple[Optional[str], str]:
"""Process reasoning content in streaming response"""
if index not in reasoning_parser_dict:
is_force_reasoning = (
self.template_manager.force_reasoning
or self._get_enable_thinking_from_request(request)
)
reasoning_parser_dict[index] = ReasoningParser(
self.tokenizer_manager.server_args.reasoning_parser,
request.stream_reasoning,
is_force_reasoning,
)
reasoning_parser = reasoning_parser_dict[index]
return reasoning_parser.parse_stream_chunk(delta)
def _get_history_tool_calls_cnt(self, request: ChatCompletionRequest) -> int:
"""Counts the number of tool calls in the request's message history.
NOTE: This method is only useful for models that include self-increasing
history tool call idx in tool calls id, such as kimi-k2
Args:
request: The chat completion request object.
Returns:
The total number of tool calls in the history, or 0 if not applicable.
"""
messages = getattr(request, "messages", [])
idx = 0
for msg in messages:
if msg.role == "assistant":
tool_calls = getattr(msg, "tool_calls", None)
idx += len(list(tool_calls)) if tool_calls is not None else 0 # noqa
return idx
def _get_enable_thinking_from_request(self, request: ChatCompletionRequest) -> bool:
"""Extracts the 'enable_thinking' flag from request chat_template_kwargs.
NOTE: This parameter is only useful for models that support enable_thinking
flag, such as Qwen3.
Args:
request_obj: The request object (or an item from a list of requests).
Returns:
The boolean value of 'enable_thinking' if found, otherwise False.
"""
if hasattr(request, "chat_template_kwargs") and request.chat_template_kwargs:
# For Qwen3 models, `enable_thinking` is supported.
if request.chat_template_kwargs.get("enable_thinking") is not None:
return request.chat_template_kwargs.get("enable_thinking")
# For DeepSeek-V3.1 models, `thinking` is supported.
elif request.chat_template_kwargs.get("thinking") is not None:
return request.chat_template_kwargs.get("thinking")
else:
return False
return False
async def _process_tool_call_stream(
self,
index: int,
delta: str,
parser_dict: Dict[int, FunctionCallParser],
content: Dict[str, Any],
request: ChatCompletionRequest,
has_tool_calls: Dict[int, bool],
):
"""Process tool calls in streaming response"""
if index not in parser_dict:
# Use JSON detector directly for required or named tool choice
if request.tool_choice == "required" or isinstance(
request.tool_choice, ToolChoice
):
parser_dict[index] = JsonArrayParser()
else:
parser_dict[index] = FunctionCallParser(
tools=request.tools,
tool_call_parser=self.tool_call_parser,
)
parser = parser_dict[index]
# Handle both FunctionCallParser and JsonArrayParser
if isinstance(parser, JsonArrayParser):
result = parser.parse_streaming_increment(delta, request.tools)
normal_text, calls = result.normal_text, result.calls
else:
normal_text, calls = parser.parse_stream_chunk(delta)
# Yield normal text
if normal_text:
choice_data = ChatCompletionResponseStreamChoice(
index=index,
delta=DeltaMessage(content=normal_text),
finish_reason=None,
)
chunk = ChatCompletionStreamResponse(
id=content["meta_info"]["id"],
created=int(time.time()),
choices=[choice_data],
model=request.model,
)
yield f"data: {chunk.model_dump_json()}\n\n"
# Yield tool calls
history_tool_calls_cnt = self._get_history_tool_calls_cnt(request)
for call_item in calls:
# Mark that this choice has tool calls
has_tool_calls[index] = True
# Tool call ID should be generated only once per tool call
if call_item.name:
# First chunk: include ID and function name
tool_call_id = self._process_tool_call_id(
call_item, history_tool_calls_cnt
)
function_name = call_item.name
else:
# Subsequent chunks: null ID and name for argument deltas
tool_call_id = None
function_name = None
tool_call = ToolCall(
id=tool_call_id,
index=call_item.tool_index,
function=FunctionResponse(
name=function_name,
arguments=call_item.parameters,
),
)
choice_data = ChatCompletionResponseStreamChoice(
index=index,
delta=DeltaMessage(tool_calls=[tool_call]),
finish_reason=None,
)
chunk = ChatCompletionStreamResponse(
id=content["meta_info"]["id"],
created=int(time.time()),
choices=[choice_data],
model=request.model,
)
yield f"data: {chunk.model_dump_json()}\n\n"
def _check_for_unstreamed_tool_args(
self,
parser: Union[FunctionCallParser, JsonArrayParser],
content: Dict[str, Any],
request: ChatCompletionRequest,
index: int,
) -> Optional[str]:
"""
Check for any remaining tool call arguments that need to be streamed
when generation finishes. This ensures tool calls are properly completed
even if the model generates the final arguments in the last chunk.
"""
# Get the detector - either from FunctionCallParser or directly if json detector
detector = parser.detector if hasattr(parser, "detector") else parser
# Only check if we have tool calls and the detector has tracked data
if (
not hasattr(detector, "prev_tool_call_arr")
or not detector.prev_tool_call_arr
):
return None
if (
not hasattr(detector, "streamed_args_for_tool")
or not detector.streamed_args_for_tool
):
return None
# Get the last tool call that was being processed
tool_index = len(detector.prev_tool_call_arr) - 1
if tool_index < 0 or tool_index >= len(detector.streamed_args_for_tool):
return None
# Get expected vs actual arguments
expected_args = detector.prev_tool_call_arr[tool_index].get("arguments", {})
expected_call = json.dumps(expected_args, ensure_ascii=False)
actual_call = detector.streamed_args_for_tool[tool_index]
# Check if there are remaining arguments to send
remaining_call = (
expected_call.replace(actual_call, "", 1)
if actual_call in expected_call
else ""
)
if remaining_call:
# Create tool call chunk with remaining arguments
tool_call = ToolCall(
id=None, # No ID for argument deltas
index=tool_index,
function=FunctionResponse(
name=None, # No name for argument deltas
arguments=remaining_call,
),
)
choice_data = ChatCompletionResponseStreamChoice(
index=index,
delta=DeltaMessage(tool_calls=[tool_call]),
finish_reason=None, # Don't send finish_reason with this chunk
)
chunk = ChatCompletionStreamResponse(
id=content["meta_info"]["id"],
created=int(time.time()),
choices=[choice_data],
model=request.model,
)
return f"data: {chunk.model_dump_json()}\n\n"
return None