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# Copyright 2023-2024 SGLang Team
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# ==============================================================================
"""Server argument declarations, resolution, and CLI registration.
Keep this file in the following top-level order:
1. Imports and the module logger.
2. Public extension-point choice lists, with each legacy ``add_*`` alias
immediately below the choice list it extends.
3. Shared (non-extensible) choice lists, scalar defaults, and deprecated
aliases. A choice list used by only one field belongs inline in that field.
4. ``ServerArgs``: fields first, then resolution/validation helpers, then CLI
registration and small query helpers. New resolution steps are appended at
the end of ``arg_groups.pipeline.run_resolution_pipeline``, immediately
marked complete, unless an earlier dependency is documented explicitly.
5. Module-level ``ServerArgs`` construction/runtime shims.
6. Networking constants and ``PortArgs``.
Model- or vendor-specific utilities belong in ``sglang.srt.arg_groups`` (or
their owning subsystem), not before ``ServerArgs`` in this module.
"""
from __future__ import annotations
import argparse
import copy
import dataclasses
import functools
import json
import logging
import tempfile
import uuid
from typing import Any, Callable, Dict, List, Literal, Optional, Union
from sglang.kernels.ops.kv_canary.consts import RealKvHashMode
from sglang.srt.arg_groups.arg_utils import NS, A, Arg, add_cli_args_from_dataclass
from sglang.srt.arg_groups.argparse_actions import (
DeprecatedAction,
DeprecatedAliasStoreAction,
DeprecatedStoreConstAction,
DeprecatedStoreTrueAction,
LoRAPathAction,
)
from sglang.srt.arg_groups.overrides import (
mamba_extra_buffer_lazy_of,
mamba_extra_buffer_of,
remote_instance_transfer_engine_of,
resolution_projection,
resolving_view,
)
from sglang.srt.environ import envs
from sglang.srt.function_call.function_call_parser import FunctionCallParser
from sglang.srt.lora.lora_registry import LoRARef
from sglang.srt.model_executor.cuda_graph_config import (
Backend,
CudaGraphConfig,
parse_cuda_graph_config_arg,
)
from sglang.srt.parser.reasoning_parser import ReasoningParser
from sglang.srt.runtime_context import (
get_context,
get_platform,
publish,
)
from sglang.srt.speculative.decoupled_spec_io import DecoupledSpecIpcConfig
from sglang.srt.utils.common import (
LORA_TARGET_ALL_MODULES,
SUPPORTED_LORA_TARGET_MODULES,
human_readable_int,
json_list_type,
nullable_str,
)
from sglang.srt.utils.network import NetworkAddress, get_free_port, wait_port_available
logger = logging.getLogger(__name__)
# --------------------------------------------------------------------------
# Extension points: out-of-tree platforms and plugins extend these lists
# before ServerArgs is constructed. Each list owns its adder on the line
# below it. A list with no adder is not an extension point -- inline it into
# the field's Arg(choices=...) instead of hoisting it here.
# --------------------------------------------------------------------------
# --- Model loading and quantization ---
LOAD_FORMAT_CHOICES = [
"auto",
"pt",
"safetensors",
"npcache",
"dummy",
"sharded_state",
"presharded",
"gguf",
# Experimental and intentionally narrow: expert_pack is validated only for
# DeepSeek-V4-Flash-0731 MXFP4 GGUF (MXFP4 experts, FP8 dense weights)
# and KIMI-K3-MXP4-DERISKED-Q2_K-*.gguf (Q2_K gate/up, Q3_K down weights):
# https://huggingface.co/unsloth/DeepSeek-V4-Flash-0731-GGUF
# https://huggingface.co/Blackfrost-AI/KIMI-K3-Q2_K-GGUF-ABLITERATED
"expert_pack",
"bitsandbytes",
"mistral",
"layered",
"flash_rl",
"remote",
"remote_instance",
"fastsafetensors",
"private",
"runai_streamer",
]
add_load_format_choices = LOAD_FORMAT_CHOICES.extend
# NOTE: LoadFormat.IPC_CACHE intentionally has no public --load-format choice.
# It is an internal dispatch format set automatically by ModelRunner when the
# weight cache is enabled (weight_cache_mode != "off"). Exposing it as a CLI
# choice let users create contradictory combos (see _handle_load_format).
# TODO: this list should likely contain only methods that support online quantization, or that support using custom quantization classes compatible with a given `quant_method` in config.json.
# Some of the choices here do NOT support online quantization.
QUANTIZATION_CHOICES = [
"awq",
"fp8", # MOE + linear online quantization.
"mxfp8", # MOE + linear online quantization.
"gptq",
"gptq_marlin",
"awq_marlin",
"bitsandbytes",
"gguf",
# Modelopt has some online quantization support through ModelOptModelLoader.
"modelopt",
"modelopt_fp8",
"modelopt_fp4",
"nvfp4_online",
"modelopt_mixed",
"petit_nvfp4",
"w8a8_int8", # mentioned in quantization.md documentation, supporting compressed-tensors quant_method.
"w8a8_fp8", # mentioned in quantization.md documentation, supporting compressed-tensors quant_method.
"moe_wna16", # custom loading logic for gptq/awq checkpoints (likely untested/unused)
"w4afp8",
"mxfp4", # MOE-only.
"auto-round",
"auto-round-int8",
"compressed-tensors", # for Ktransformers
"modelslim", # for NPU
"mxfp_w4a8", # for NPU W4A8 (MXFP4 weights + MXFP8 activations)
"quark", # AMD Quark quantizer (FP8 / MXFP4 / Int4FP8 etc.)
"quark_int4fp8_moe",
"quark_mxfp4", # Online MOE + linear quantization (incl. NVFP4 -> MXFP4 requantization).
# Apple Silicon MLX backend — on-the-fly quantization of fp16 weights at load
# time via mlx.nn.quantize. Only takes effect when SGLANG_USE_MLX=1.
"mlx_q4", # 4 bits, group_size=64 (mlx-community default)
"mlx_q8", # 8 bits, group_size=64
"unquant",
"humming",
]
add_quantization_method_choices = QUANTIZATION_CHOICES.extend
# --- Attention backends ---
ATTENTION_BACKEND_CHOICES = [
# Common
"triton",
"torch_native",
"flex_attention",
"dsa",
"nsa", # Deprecated alias for "dsa"
"dsv4",
"compressed", # Deprecated alias for "dsv4"
# NVIDIA specific
"cutlass_mla",
"fa3",
"fa4",
"flashinfer",
"flashmla",
"trtllm_mla",
"cutedsl_mla",
"tokenspeed_mla",
"trtllm_mha",
"dual_chunk_flash_attn",
"hpc_ops", # HPC-Ops (https://github.com/Tencent/hpc-ops), Hopper (SM90) only, requires --page-size 64
"minicpm_flashattn",
"minicpm_flashinfer",
# AMD specific
"aiter",
"wave",
# Other platforms
"intel_amx",
"ascend",
"intel_xpu",
]
add_attention_backend_choices = ATTENTION_BACKEND_CHOICES.extend
# trtllm_mha is valid for decode-only dense-MQA drafts. DFLASH rejects it
# earlier when its per-layer attention requirements are not met.
DRAFT_ATTENTION_BACKEND_CHOICES = [
"flashinfer",
"fa3",
"fa4",
"triton",
"ascend",
"trtllm_mha",
]
add_draft_attention_backend_choices = DRAFT_ATTENTION_BACKEND_CHOICES.extend
# Attention backends whose kernels read the chunked prefix-cache layout.
# Out-of-tree platforms may extend this list (via
# add_chunked_prefix_cache_attention_backend) before ServerArgs construction;
# the chunked-prefix gate is evaluated during resolution.
CHUNKED_PREFIX_CACHE_SUPPORTED_ATTENTION_BACKENDS = [
"flashinfer",
"fa3",
"fa4",
"flashmla",
"cutedsl_mla",
"cutlass_mla",
"trtllm_mla",
"tokenspeed_mla",
]
add_chunked_prefix_cache_attention_backend = (
CHUNKED_PREFIX_CACHE_SUPPORTED_ATTENTION_BACKENDS.append
)
DETERMINISTIC_ATTENTION_BACKEND_CHOICES = [
"ascend",
"fa3",
"fa4",
"flashinfer",
"intel_xpu",
"triton",
]
add_deterministic_attention_backend_choices = (
DETERMINISTIC_ATTENTION_BACKEND_CHOICES.extend
)
RADIX_SUPPORTED_DETERMINISTIC_ATTENTION_BACKEND = ["ascend", "fa3", "fa4", "triton"]
add_radix_supported_deterministic_attention_backend_choices = (
RADIX_SUPPORTED_DETERMINISTIC_ATTENTION_BACKEND.extend
)
# --- Transport ---
DISAGG_TRANSFER_BACKEND_CHOICES = [
"mooncake",
"nixl",
"ascend",
"fake",
"mori",
"mooncake_tcp",
]
add_disagg_transfer_backend_choices = DISAGG_TRANSFER_BACKEND_CHOICES.extend
# --- Sampling and grammar ---
GRAMMAR_BACKEND_CHOICES = ["xgrammar", "outlines", "llguidance", "none"]
add_grammar_backend_choices = GRAMMAR_BACKEND_CHOICES.extend
SAMPLING_BACKEND_CHOICES = {"flashinfer", "pytorch", "ascend"}
# --- MoE and GEMM runners ---
MOE_RUNNER_BACKEND_CHOICES = [
"auto",
"deep_gemm",
"triton",
"triton_kernel",
"flashinfer_trtllm",
"experimental_sgl_trtllm",
"flashinfer_trtllm_routed",
"flashinfer_cutlass",
"flashinfer_mxfp4",
"flashinfer_cutedsl",
"cutlass",
"aiter",
"marlin",
"humming",
"experimental_sgl_marlin",
"hpc_ops", # HPC-Ops (https://github.com/Tencent/hpc-ops), FP8 MoE on Hopper (SM90) only
"megamoe",
"intel_xpu",
]
add_moe_runner_backend_choices = MOE_RUNNER_BACKEND_CHOICES.extend
MXFP8_MOE_RUNNER_BACKEND_CHOICES = [
"cutlass",
"deep_gemm",
"flashinfer_trtllm",
"flashinfer_trtllm_routed",
]
add_mxfp8_moe_runner_backend_choices = MXFP8_MOE_RUNNER_BACKEND_CHOICES.extend
FP8_GEMM_RUNNER_BACKEND_CHOICES = [
"auto",
"deep_gemm",
"flashinfer_trtllm",
"flashinfer_cutlass",
"flashinfer_deepgemm",
"flashinfer_cutedsl",
"cutlass",
"triton",
"aiter",
]
add_fp8_gemm_runner_backend_choices = FP8_GEMM_RUNNER_BACKEND_CHOICES.extend
FP4_GEMM_RUNNER_BACKEND_CHOICES = [
"auto",
"flashinfer_cudnn",
"flashinfer_cutedsl",
"flashinfer_cutlass",
"flashinfer_trtllm",
"marlin",
]
add_fp4_gemm_runner_backend_choices = FP4_GEMM_RUNNER_BACKEND_CHOICES.extend
# --- Cache and scheduling policy ---
RADIX_EVICTION_POLICY_CHOICES = ["lru", "lfu", "slru", "priority"]
add_radix_eviction_policy_choices = RADIX_EVICTION_POLICY_CHOICES.extend
# --- Reinforcement learning ---
RL_ON_POLICY_TARGET_CHOICES = ["fsdp"]
add_rl_on_policy_target_choices = RL_ON_POLICY_TARGET_CHOICES.extend
# --- Linear attention ---
LINEAR_ATTN_KERNEL_BACKEND_CHOICES = [
"triton",
"cutedsl",
"flashinfer",
"flashkda",
"nvidia_kda",
"ptx_kda",
"helion",
"intel_xpu",
]
add_linear_attn_kernel_backend_choices = LINEAR_ATTN_KERNEL_BACKEND_CHOICES.extend
# --------------------------------------------------------------------------
# Add new extension points at the end of the matching group above. A new
# choice list is inlined into its field by default; hoisting one here makes
# it public API for out-of-tree code and is a deliberate decision.
# --------------------------------------------------------------------------
@dataclasses.dataclass
class ServerArgs:
"""Server-wide configuration for SGLang.
Adding new arguments
--------------------
1. **Place the field in the right section.** Arguments are grouped by
comment blocks (``# Model and tokenizer``, ``# LoRA``, etc.).
Add new fields to the matching section, or create a new section
with a ``# ---`` banner when none fits.
2. **Use the ``A[T, ...]`` annotation.** ``A`` is an alias for
``typing.Annotated``. The primary CLI flag is auto-derived from the
field name (``tp_size`` → ``--tp-size``). Use ``aliases`` for
longer alternate names
(``aliases=["--tensor-parallel-size"]``)::
# Bare string — simplest form (just help text):
host: A[str, "The host of the HTTP server."] = "127.0.0.1"
trust_remote_code: A[bool, "Whether to allow custom models."] = False
# Arg(...) — when you need choices, aliases, type_parser, etc.:
load_format: A[str, Arg(help="...", choices=CHOICES)] = "auto"
model_path: A[str, Arg(help="...", aliases=["--model"])]
See ``Arg`` in ``arg_groups/arg_utils.py`` for the full list of
supported metadata (``choices``, ``aliases``, ``type_parser``,
``nargs``, ``const``, ``action``, ``no_cli``, …).
3. **Manual entries in ``add_cli_args`` — only for special cases.**
A few arguments cannot use the annotation style and must be
registered manually in ``add_cli_args``:
- **Deprecated flags** that redirect to another field via
``DeprecatedAction`` / ``DeprecatedAliasStoreAction`` / etc.
- **Dynamic choices** computed at runtime (e.g. ``reasoning_parser``
whose choices come from a plugin registry).
- The ``--config`` meta-argument (not a dataclass field).
Everything else should use the ``A[T, ...]`` annotation.
"""
# -------------------------------------------------------------------------
# Model and tokenizer
# -------------------------------------------------------------------------
model_path: A[
str,
Arg(
help="The path of the model weights. This can be a local folder or a Hugging Face repo ID.",
aliases=["--model"],
),
NS("model"),
]
tokenizer_path: A[Optional[str], "The path of the tokenizer.", NS("serving")] = None
tokenizer_mode: A[
str,
Arg(
help="Tokenizer mode. 'auto' will use the fast tokenizer if available, "
"and 'slow' will always use the slow tokenizer.",
choices=["auto", "slow"],
),
NS("serving"),
] = "auto"
tokenizer_backend: A[
str,
Arg(
help="Tokenizer backend. 'huggingface' uses the default HuggingFace "
"tokenizers library, and 'fastokens' uses the fastokens library "
"for faster tokenization. Requires the fastokens package to be installed.",
choices=["huggingface", "fastokens"],
),
NS("serving"),
] = "huggingface"
tokenizer_worker_num: A[
int, "The worker num of the tokenizer manager.", NS("serving")
] = 1
detokenizer_worker_num: A[
int, "The worker num of the detokenizer manager.", NS("serving")
] = 1
skip_tokenizer_init: A[
bool,
"If set, skip init tokenizer and pass input_ids in generate request.",
NS("serving"),
] = False
load_format: A[
str,
Arg(
help="The format of the model weights to load. "
'"auto" will try to load the weights in the safetensors format '
"and fall back to the pytorch bin format if safetensors format "
"is not available. "
'"pt" will load the weights in the pytorch bin format. '
'"safetensors" will load the weights in the safetensors format. '
'"npcache" will load the weights in pytorch format and store '
"a numpy cache to speed up the loading. "
'"dummy" will initialize the weights with random values, '
"which is mainly for profiling."
'"gguf" will load the weights in the gguf format. '
'"expert_pack" is experimental and loads only the validated '
"DeepSeek-V4-Flash-0731 MXFP4 or text-only Kimi-K3 Q2_K GGUF "
"model with routed experts stored in an SSD expert pack. "
'"bitsandbytes" will load the weights using bitsandbytes '
"quantization."
'"layered" loads weights layer by layer so that one can quantize a '
"layer before loading another to make the peak memory envelope "
"smaller."
'"presharded" performs a normal first-time load (with quantization), '
"then dumps a per-rank/per-tensor sharded checkpoint with content "
"deduplication into "
"<model_path>/presharded/<parallelism+quant subfolder>/. "
"Subsequent runs with the same parallelism+quantization config "
"load directly from this presharded checkpoint and skip "
"re-quantization. "
"The dump directory must be on a shared filesystem across all "
"ranks/nodes. Optional model_loader_extra_config roots: "
"presharded_path (target) and draft_presharded_path (speculative "
"draft); each replaces <model_path>/presharded and still gets a "
"config subfolder appended. Use a writable path when model_path "
"is read-only (e.g. HF cache mounts).",
choices=LOAD_FORMAT_CHOICES,
),
NS("model"),
] = "auto"
model_loader_extra_config: A[
str,
"Extra config for model loader. This will be passed to the model loader "
"corresponding to the chosen load_format. For load_format=presharded, "
"JSON may include presharded_path (target cache root), "
"draft_presharded_path (draft cache root), max_file_bytes, "
"hash_num_threads, and verify_on_load.",
NS("model"),
] = "{}"
trust_remote_code: A[
bool,
"Whether or not to allow for custom models defined on the Hub in their own modeling files.",
NS("model"),
] = False
context_length: A[
Optional[int],
Arg(
help="The model's maximum context length. Defaults to None (will use the value from the model's config.json instead)."
f"\n\n{human_readable_int.__doc__}",
type_parser=human_readable_int,
),
NS("model"),
] = None
is_embedding: A[
bool, "Whether to use a CausalLM as an embedding model.", NS("model")
] = False
enable_multimodal: A[
Optional[bool],
"Enable the multimodal functionality for the served model. If the model being served is not multimodal, nothing will happen",
NS("mm"),
] = None
revision: A[
Optional[str],
"The specific model version to use. It can be a branch name, a tag name, or a commit id. If unspecified, will use the default version.",
NS("model"),
] = None
model_impl: A[
str,
Arg(
help=(
"Which implementation of the model to use.\n\n"
'* "auto" will try to use the SGLang implementation if it exists '
"and fall back to the Transformers implementation if no SGLang "
"implementation is available.\n"
'* "sglang" will use the SGLang model implementation.\n'
'* "transformers" will use the Transformers model '
'* "mindspore" will use the MindSpore model '
"implementation.\n"
)
),
NS("model"),
] = "auto"
model_config_parser: A[
str,
Arg(
help=(
'Which model-config parser to use. "auto" picks "mistral" '
'via the is_mistral_model name heuristic, else "hf" '
"(AutoConfig over config.json). Plugins can register additional "
"parsers via @register_model_config_parser."
)
),
NS("model"),
] = "auto"
json_model_override_args: A[
str,
"A dictionary in JSON string format used to override default model configurations.",
NS("model"),
] = "{}"
# -------------------------------------------------------------------------
# Quantization and data type
# -------------------------------------------------------------------------
dtype: A[
str,
Arg(
help=(
"Data type for model weights and activations.\n\n"
'* "auto" will use FP16 precision for FP32 and FP16 models, and '
"BF16 precision for BF16 models.\n"
'* "half" for FP16. Recommended for AWQ quantization.\n'
'* "float16" is the same as "half".\n'
'* "bfloat16" for a balance between precision and range.\n'
'* "float" is shorthand for FP32 precision.\n'
'* "float32" for FP32 precision.'
),
choices=["auto", "half", "float16", "bfloat16", "float", "float32"],
resolvable=True,
),
NS("model"),
] = "auto"
quantization: A[
Optional[str],
Arg(
help="The quantization method.",
choices=QUANTIZATION_CHOICES,
resolvable=True,
),
NS("model"),
] = None
quantization_param_path: A[
Optional[str],
Arg(
help=(
"Path to the JSON file containing the KV cache scaling factors. "
"This should generally be supplied, when KV cache dtype is FP8. "
"Otherwise, KV cache scaling factors default to 1.0, which may "
"cause accuracy issues. "
),
type_parser=nullable_str,
),
NS("model"),
] = None
kv_cache_dtype: A[
str,
Arg(
help=(
'Data type for kv cache storage. "auto" will use model data type. '
'"bf16" or "bfloat16" for BF16 KV cache. "fp8_e5m2" and '
'"fp8_e4m3" are supported for CUDA 11.8+. "mxfp8" is supported '
'by the FA4 backend. "nvfp4" selects '
'the NVFP4 FP4 E2M1 KV cache recipe; "fp4_mx_block16" '
"selects the MX-style block-size-16 FP4 E2M1 KV cache "
"recipe. Both require CUDA 12.8+ and PyTorch 2.8.0+"
),
choices=[
"auto",
"fp8_e5m2",
"fp8_e4m3",
"mxfp8",
"bf16",
"bfloat16",
"nvfp4",
"fp4_mx_block16",
"fp4_e2m1",
],
resolvable=True,
),
NS("model"),
] = "auto"
enable_fp32_lm_head: A[
bool, "If set, the LM head outputs (logits) are in FP32.", NS("exec.features")
] = False
modelopt_quant: A[
Optional[Union[str, Dict]],
(
"The ModelOpt quantization configuration. Supported values: 'fp8', "
"'int4_awq', 'w4a8_awq', 'nvfp4', 'nvfp4_awq'. This requires the "
"NVIDIA Model Optimizer library to be installed: pip install "
"nvidia-modelopt"
),
NS("model"),
] = None
modelopt_checkpoint_restore_path: A[
Optional[str],
(
"Path to restore a previously saved ModelOpt quantized checkpoint. "
"If provided, the quantization process will be skipped and the model "
"will be loaded from this checkpoint."
),
NS("model"),
] = None
modelopt_checkpoint_save_path: A[
Optional[str],
(
"Path to save the ModelOpt quantized checkpoint after quantization. "
"This allows reusing the quantized model in future runs."
),
NS("model"),
] = None
modelopt_export_path: A[
Optional[str],
(
"Path to export the quantized model in HuggingFace format after "
"ModelOpt quantization. The exported model can then be used directly "
"with SGLang for inference. If not provided, the model will not be "
"exported."
),
NS("model"),
] = None
quantize_and_serve: A[
bool,
(
"Quantize the model with ModelOpt and immediately serve it without "
"exporting. This is useful for development and prototyping. For "
"production, it's recommended to use separate quantization and "
"deployment steps."
),
NS("model"),
] = False
rl_quant_profile: A[
Optional[str],
"Path to the FlashRL quantization profile. Required when using --load-format flash_rl.",
NS("model"),
] = None # For flash_rl load format
enable_tf32_matmul: A[
bool,
Arg(
help="Enable float32 matmuls to use TensorFloat32 precision for better performance (via torch.set_float32_matmul_precision). CUDA only.",
resolvable=True,
),
NS("exec.features"),
] = False
# -------------------------------------------------------------------------
# Memory and scheduling
# -------------------------------------------------------------------------
mem_fraction_static: A[
Optional[float],
"The fraction of the memory used for static allocation (model weights and KV cache memory pool). Use a smaller value if you see out-of-memory errors.",
NS("schedule"),
] = None
max_running_requests: A[
Optional[int], "The maximum number of running requests.", NS("schedule")
] = None
max_queued_requests: A[
Optional[int],
"The maximum number of queued requests. This option is ignored when using disaggregation-mode.",
NS("schedule"),
] = None
max_total_tokens: A[
Optional[int],
Arg(
help=(
"The maximum number of tokens in the memory pool. If not "
"specified, it will be automatically calculated based on the "
"memory usage fraction. This option is typically used for "
"development and debugging purposes."
+ f"\n\n{human_readable_int.__doc__}"
),
type_parser=human_readable_int,
),
NS("schedule"),
] = None
chunked_prefill_size: A[
Optional[int],
"The maximum number of tokens in a chunk for the chunked prefill. Setting this to -1 means disabling chunked prefill.",
NS("schedule"),
] = None
prefill_decode_interval: A[
int,
"The number of decode rounds to run after a prefill batch before scheduling the next prefill. In data-parallel attention mode, the interval is synchronized across all DP ranks. Set to 0 to disable.",
NS("schedule"),
] = 0
enable_dynamic_chunking: A[
bool,
"Enable dynamic chunk size adjustment for pipeline parallelism. When enabled, chunk sizes are dynamically calculated based on fitted function to maintain consistent execution time across chunks.",
NS("schedule"),
] = False
max_prefill_tokens: A[
int,
Arg(
help=(
"The maximum number of tokens in a prefill batch. The real bound "
"will be the maximum of this value and the model's maximum "
"context length." + f"\n\n{human_readable_int.__doc__}"
),
type_parser=human_readable_int,
),
NS("schedule"),
] = 16384
prefill_max_requests: A[
Optional[int],
"The maximum number of requests in a prefill batch. If not specified, there is no limit.",
NS("schedule"),
] = None
schedule_policy: A[
str,
Arg(
help="The scheduling policy of the requests.",
choices=[
"lpm",
"random",
"fcfs",
"dfs-weight",
"lof",
"priority",
"routing-key",
],
),
NS("schedule"),
] = "fcfs"
enable_priority_scheduling: A[
bool,
"Enable priority scheduling. Requests with higher priority integer values will be scheduled first by default.",
NS("schedule"),
] = False
disable_priority_preemption: A[
bool, "Disable priority scheduling preemption.", NS("schedule")
] = False
default_priority_value: A[
Optional[int],
"Default priority for requests without explicit priority.",
NS("schedule"),
] = None
abort_on_priority_when_disabled: A[
bool,
"If set, abort requests that specify a priority when priority scheduling is disabled.",
NS("schedule"),
] = False
schedule_low_priority_values_first: A[
bool,
"If specified with --enable-priority-scheduling, the scheduler will schedule requests with lower priority integer values first.",
NS("schedule"),
] = False
priority_scheduling_preemption_threshold: A[
int,
"Minimum difference in priorities for an incoming request to have to preempt running request(s).",
NS("schedule"),
] = 10
retraction_policy: A[
str,
Arg(
help=(
"The decode retraction policy to use when the KV cache is full. "
"'length' preserves the existing behavior and retracts short-output, "
"long-input requests first. 'priority' retracts lower-priority "
"requests first, using the same priority direction as priority "
"scheduling."
),
choices=["length", "priority"],
),
NS("schedule"),
] = "length"
schedule_conservativeness: A[
float,
"How conservative the schedule policy is. A larger value means more conservative scheduling. Use a larger value if you see requests being retracted frequently.",
NS("schedule"),
] = 1.0
page_size: A[
Optional[int],
Arg(help="The number of tokens in a page.", resolvable=True),
NS("schedule"),
] = None
c128_page_size: A[
int,
"The physical page size of the NPU DSV4 C128 KV cache. Must be a positive multiple of 16.",
NS("schedule"),
] = 16
swa_full_tokens_ratio: A[
float,
Arg(
help=(
"The ratio of SWA layer KV tokens / full layer KV tokens, regardless "
"of the number of swa:full layers. It should be between 0 and 1. "
"E.g. 0.5 means if each swa layer has 50 tokens, then each full "
"layer has 100 tokens."
),
resolvable=True,
),
NS("schedule"),
] = 0.8
disable_hybrid_swa_memory: A[
bool,
Arg(help="Disable the hybrid SWA memory pool.", resolvable=True),
NS("schedule"),
] = False
radix_eviction_policy: A[
str,
Arg(
help=(
"The eviction policy of radix trees. 'lru' stands for Least "
"Recently Used, 'lfu' stands for Least Frequently Used, 'slru' "
"stands for Segmented Least Recently Used, and 'priority' evicts "
"lower-priority requests first. See "
"https://docs.sglang.io/docs/advanced_features/radix_eviction_policy "
"for what each policy optimizes for."
),
choices=RADIX_EVICTION_POLICY_CHOICES,
),
NS("memory"),
] = "lru"
radix_eviction_policy_config: A[
Optional[Dict[str, Any]],
Arg(
help=(
"Tuning parameters for --radix-eviction-policy, as a json object "
"passed to the policy as keyword arguments. Only 'slru' takes any "
"today: protected_threshold (int, default 2), e.g. "
"'{\"protected_threshold\": 4}'. An unrecognized key fails at "
"startup, naming the key and the policy. See "
"https://docs.sglang.io/docs/advanced_features/radix_eviction_policy#policy-parameters "
"for the full parameter list."
),
type_parser=json.loads,
),
NS("memory"),
] = None
prefill_only_disable_kv_cache: A[
bool,
"Skip the physical KV cache allocation for embedding-mode prefill-only workloads. Currently only valid with --is-embedding, --chunked-prefill-size=-1, --disable-radix-cache, an FA prefill backend, and non-FP4 KV cache so the fa_skip_kv_cache path is active (no layer reads or writes the cache). Other prefill-only workloads such as scoring/MIS may benefit from this later once their attention paths stop using paged KV. Scheduler admission accounting is unchanged; per-layer K/V tensors are sized to (page_size, head_num, head_dim) placeholders so GPU memory is not wasted.",
NS("schedule"),
] = False
disable_radix_cache: A[
bool,
Arg(
help="Disable RadixAttention for prefix caching.",
resolvable=True,
),
NS("memory"),
] = False
enable_page_major_kv_layout: A[
bool,
"Enable the page-major KV layout: lay out the Mamba state and full/SWA "
"KV caches in a page-granularity envelope (page is the outermost axis, "
"layer-major within a page) instead of the default per-layer "
"(layer-major) layout. Requires the Triton attention / linear-attn / "
"Mamba backends.",
NS("memory"),
] = False
enable_unified_memory: A[
bool,
"Replace the statically-partitioned hybrid-model pools (full-attn KV + "
"SWA/Mamba state) with one byte buffer split dynamically between "
"sub-pools. Requires the Triton attention / linear-attn / Mamba "
"backends; not yet compatible with PD disaggregation or speculative "
"decoding.",
NS("memory"),
] = False
disable_chunked_prefix_cache: A[
bool,
"Disable chunked prefix cache feature for deepseek, which should save overhead for short sequences.",
NS("schedule"),
] = False
disable_overlap_schedule: A[
bool,
Arg(
help="Disable the overlap scheduler, which overlaps the CPU scheduler with GPU model worker.",
resolvable=True,
),
NS("schedule"),
] = False
num_continuous_decode_steps: A[
int,
"Run multiple continuous decoding steps to reduce scheduling overhead. This can potentially increase throughput but may also increase time-to-first-token latency. The default value is 1, meaning only run one decoding step at a time.",
NS("schedule"),
] = 1
scheduler_recv_interval: A[
int,
"The interval to poll requests in scheduler. Can be set to >1 to reduce the overhead of this.",
NS("schedule"),
] = 1
enable_mixed_chunk: A[
bool,
"Enabling mixing prefill and decode in a batch when using chunked prefill.",
NS("schedule"),
] = False
# -------------------------------------------------------------------------
# Distributed topology and parallelism (TP, PP, DP, CP)
# -------------------------------------------------------------------------
nccl_port: A[
Optional[int],
"The port for NCCL distributed environment setup. Defaults to a random port.",
NS("parallel"),
] = None
dist_timeout: A[
Optional[int],
"Set timeout for torch.distributed initialization.",
NS("parallel"),
] = None
dist_init_addr: A[
Optional[str],
Arg(
help="The host address for initializing distributed backend (e.g., `192.168.0.2:25000`).",
aliases=["--nccl-init-addr"],
),
NS("parallel"),
] = None
gated_launch_port: A[
Optional[int],
"The port of the gated launch control server. When set, every rank blocks right after the distributed environment is initialized, before any sizable GPU allocation, until `POST /gate/activate` is sent to this port on the host of the first rank. This lets an external orchestrator defer the memory hungry part of startup to a safe window. Defaults to None, which disables the gate.",
NS("parallel"),
] = None
nnodes: A[int, "The number of nodes.", NS("parallel")] = 1
node_rank: A[int, "The node rank.", NS("parallel")] = 0
tp_size: A[
int,
Arg(
help="The tensor parallelism size.",
aliases=["--tensor-parallel-size"],
),
NS("parallel"),
] = 1
dcp_size: A[
int,
Arg(
help="The decode context parallelism size.",
aliases=["--decode-context-parallel-size"],
),
NS("parallel"),
] = 1
pp_size: A[
int,
Arg(
help="The pipeline parallelism size.",
aliases=["--pipeline-parallel-size"],
),
NS("parallel"),
] = 1
pp_max_micro_batch_size: A[
Optional[int],
"The maximum micro batch size in pipeline parallelism.",
NS("parallel"),
] = None
pp_async_batch_depth: A[
int, "The async batch depth of pipeline parallelism.", NS("parallel")
] = 0
dp_size: A[
int,
Arg(
help="The data parallelism size.",
aliases=["--data-parallel-size"],
),
NS("parallel"),
] = 1
load_balance_method: A[
str,
Arg(
help="The load balancing strategy for data parallelism.",
choices=[
"auto",
"round_robin",
"follow_bootstrap_room",
"total_requests",
"total_tokens",
],
),
NS("parallel"),
] = "auto"
attn_cp_size: A[
int,
Arg(
help="The attention context parallelism size.",
aliases=["--attention-context-parallel-size"],
resolvable=True,
),
NS("parallel"),
] = 1
moe_dp_size: A[
int,
Arg(
help="The moe data parallelism size.",
aliases=["--moe-data-parallel-size"],
),
NS("parallel"),
] = 1
dwdp_size: A[
int,
Arg(
help="DWDP (Distributed Weight Data Parallelism) group size. "
"When > 1, MoE prefill uses weight prefetch instead of token all-to-all. "
"Must equal tp_size. Only supported with --disaggregation-mode null or prefill.",
),
NS("parallel"),
] = 1
dcp_comm_backend: A[
str,
Arg(
help="Communication backend for the decode context-parallel (DCP) "
"attention reduction: 'ag_rs' (AllGather + ReduceScatter), 'a2a' "
"(fused NCCL All-to-All exchange of output+LSE + local Triton LSE "
"combine), or 'fi_a2a' (FlashInfer MNNVL All-to-All kernel; requires "
"SM90+ and MNNVL fabric memory, e.g. GB200 NVL72).",
choices=["ag_rs", "a2a", "fi_a2a"],
resolvable=True,
),
NS("parallel"),
] = "ag_rs"
dcp_replicate_q_proj: A[
Optional[bool],
Arg(
help="For MLA decode context parallelism with the a2a/fi_a2a "
"backend: replicate the Q projection so each DCP rank computes the "
"full-head query locally (redundant projection compute), eliminating "
"the per-layer head-dim all-gather of Q. Trades a small amount of "
"extra GEMM for one fewer collective per layer. Use "
"--no-dcp-replicate-q-proj to disable the model-specific default.",
action=argparse.BooleanOptionalAction,
resolvable=True,
),
NS("parallel"),
] = None
enable_prefill_cp: A[
bool,
"Enable context parallelism for the prefill phase. Select the layout with --cp-strategy.",
NS("parallel"),
] = False
cp_strategy: A[
Optional[str],
Arg(
help="Sharding strategy for prefill CP. 'zigzag' is the former in-seq-split mode; 'interleave' is the former round-robin-split mode.",
choices=("zigzag", "interleave"),
),
NS("parallel"),
] = None
# Split DSA GPU KV/indexer cache layers across CP ranks.
enable_dsa_cache_layer_split: A[
bool,
"Split DSA (DeepSeek Sparse Attention) GPU KV/indexer cache layers across context-parallel ranks to reduce per-rank KV memory. Currently only supported with the mooncake transfer backend (mooncake / mooncake_tcp); mori/nixl support will be added later by the community.",
NS("parallel"),
] = False
enable_dsa_prefill_context_parallel: A[bool, Arg(no_cli=True), NS("parallel")] = (
False
)
dsa_prefill_cp_mode: A[str, Arg(no_cli=True), NS("parallel")] = "round-robin-split"
enable_prefill_context_parallel: A[bool, Arg(no_cli=True), NS("parallel")] = False
prefill_cp_mode: A[str, Arg(no_cli=True), NS("parallel")] = "in-seq-split"
enable_cp_decode_attn_tp: A[
bool,
"Enable attention tensor-parallel weight slicing during decode under context parallel (cp_size>1). Slices the replicated attention linears to the local CP partition, eliminating redundant decode GEMMs.",
NS("parallel"),
] = False
# DP attention
enable_dp_attention: A[
bool,
Arg(
help="Enabling data parallelism for attention and tensor parallelism for FFN. The dp size should be equal to the tp size. Currently DeepSeek-V2 and Qwen 2/3 MoE models are supported.",
resolvable=True,
),
NS("parallel"),
] = False
enable_dp_attention_local_control_broadcast: A[
bool,
"With DP-attention, send control messages to every DP group leader and broadcast within attn_tp_group instead of the full tp_group. Eliminates a costly all-ranks gloo sync on every scheduler iteration.",
NS("parallel"),
] = False
enable_dp_lm_head: A[
bool,
Arg(
help="Enable vocabulary parallel across the attention TP group to avoid all-gather across DP groups, optimizing performance under DP attention.",
resolvable=True,
),
NS("parallel"),
] = False
enable_tp_lm_head_all_to_all: A[
Optional[bool],
Arg(
help="Use all-to-all instead of TP all-gather followed by DP scatter "
"for the TP-sharded LM head under DP attention. By default this is "
"enabled only on decode-only PD nodes with pure DP attention "
"(tp_size == dp_size > 1 and attn_cp_size == 1), and disabled on "
"prefill-only and colocated nodes. Pass "
"--no-enable-tp-lm-head-all-to-all to opt out. The path is "
"incompatible with --enable-dp-lm-head; batches without an equal "
"padded row count fall back to the existing all-gather path.",
action=argparse.BooleanOptionalAction,
resolvable=True,
),
NS("parallel"),
] = None
enable_attn_tp_input_scattered: A[
bool,
"Allow input of attention to be scattered when only using tensor parallelism, to reduce the computational load of operations such as qkv latent.",
NS("parallel"),
] = False
enable_shared_experts_attn_tp: A[
bool,
"Shard shared expert weights across the attention TP group when using an expert-parallel all-to-all backend.",
NS("parallel"),
] = False
enable_dense_mlp_attn_tp: A[
bool,
"Shard dense MLP weights across the attention TP group under DP attention.",
NS("parallel"),
] = False
enable_layernorm_sp: A[
bool,
"Enable Megatron-style sequence parallelism (arXiv:2205.05198) for the "
"LayerNorm/residual regions under pure tensor parallelism: the row-parallel "
"all-reduce becomes reduce-scatter + all-gather, so LayerNorm runs on "
"sequence-sharded activations with no extra communication volume. "
"Prefill only; Qwen3 dense; requires tp_size > 1 and NVLink/NVSwitch.",
NS("parallel"),
] = False
disable_attn_tp_gather: A[
bool,
"Disable scheduler-side attn_tp_gather (the upstream SP path "
"that pads num_tokens to attn_tp_size and pre-allocates a gathered "
"buffer). Use for models that manage SP scatter/gather at the "
"model level (e.g., perform their own all_gather/reduce_scatter "
"inside attention) and do not consume the upstream gathered_buffer. "
"Without this, the cuda graph runner pads num_tokens to attn_tp_size, "
"which can cause kernel autotuners to select wrong-sized variants "
"at small batches.",
NS("parallel"),
] = False
enable_p2p_check: A[
bool,
"Enable P2P check for GPU access, otherwise the p2p access is allowed by default.",
NS("parallel"),
] = False
# -------------------------------------------------------------------------
# Device info and server timeout
# -------------------------------------------------------------------------
device: A[
Optional[str],
"The device to use ('cuda', 'xpu', 'hpu', 'npu', 'cpu', 'musa'). Defaults to auto-detection if not specified.",
NS("device"),
] = None
base_gpu_id: A[
int,
"The base GPU ID to start allocating GPUs from. Useful when running multiple instances on the same machine.",
NS("device"),
] = 0
gpu_id_step: A[
int,
"The delta between consecutive GPU IDs that are used. For example, setting it to 2 will use GPU 0,2,4,...",
NS("device"),
] = 1
random_seed: A[Optional[int], "The random seed.", NS("device")] = None
mlx_enable_sampling: A[
bool,
(
"MLX backend only: sample decode tokens (temperature / top-k / "
"top-p / min-p) instead of greedy argmax. Sampling runs inside "
"the lazy MLX graph, so it works with the overlap scheduler; "
"first tokens from prefill/extend are sampled too. Greedy "
"requests keep exact argmax behavior. Also enables on the MLX "
"path: grammar vocab masks and custom logit processors (these "
"break decode chaining per step; custom processors run on "
"pure-decode steps only), logit_bias, output logprobs (sampled "
"token / top-k / token_ids; prompt input logprobs are not "
"computed), NaN sanitization (SGLANG_SANITIZE_NAN_LOGITS), and "
"per-request sampling_seed under "
"--enable-deterministic-inference (deterministic within MLX "
"only). Penalties are not applied."
),
NS("device"),
] = False
watchdog_timeout: A[
float,
"Set watchdog timeout in seconds. If a forward batch takes longer than this, the server will crash to prevent hanging.",
NS("device"),
] = 300
soft_watchdog_timeout: A[
Optional[float],
"Set soft watchdog timeout in seconds. If a forward batch takes longer than this, the server will dump information for debugging.",
NS("device"),
] = None
sleep_on_idle: A[bool, "Reduce CPU usage when sglang is idle.", NS("device")] = (
False
)
use_ray: A[
bool, "Use Ray actors for scheduler process management.", NS("device")
] = False
custom_sigquit_handler: A[Optional[Callable], NS("device")] = None
numa_node: A[
Optional[List[int]],
"Sets the numa node for the subprocesses. i-th element corresponds to i-th subprocess. If unset, will be automatically detected on NUMA systems.",
NS("device"),
] = None
gc_threshold: A[
Optional[List[int]],
"Set the garbage collection thresholds (the collection frequency). Accepts 1 to 3 integers.",
NS("device"),
] = None
# -------------------------------------------------------------------------
# HTTP server
# -------------------------------------------------------------------------
host: A[str, "The host of the HTTP server.", NS("serving")] = "127.0.0.1"
port: A[int, "The port of the HTTP server.", NS("serving")] = 30000
fastapi_root_path: A[
str, "App is behind a path based routing proxy.", NS("serving")
] = ""
smg_grpc_mode: A[
bool,
"Use the legacy SMG gRPC server (smg-grpc-servicer) instead of the HTTP "
"server. Replaces the deprecated --grpc-mode.",
NS("serving"),
] = False
grpc_mode: A[
bool,
"(Deprecated, use --smg-grpc-mode) Legacy SMG gRPC server selector.",
NS("serving"),
] = False
grpc_port: A[
Optional[int],
"Port for the native gRPC server, started alongside HTTP. Setting this "
"(or SGLANG_GRPC_PORT) enables the native gRPC server; it is off by "
"default. In legacy --smg-grpc-mode this is the SMG server port and "
"defaults to --port + 10000.",
NS("serving"),
] = None
# Env-only (SGLANG_GRPC_WORKER_THREADS); a field so the projection sees it.
grpc_worker_threads: A[Optional[int], Arg(no_cli=True), NS("serving")] = None
sidecar: A[
Optional[str],
"Start a locally managed sidecar against the native gRPC server. "
"The selected module must expose main(argv) and read the resolved "
"native gRPC endpoint from SGLANG_GRPC_ENDPOINT. Requires --grpc-port "
"or SGLANG_GRPC_PORT.",
NS("serving"),
] = None
sidecar_args: A[
Optional[List[str]],
Arg(
help="JSON array passed to the selected sidecar module's "
"main(argv) function. --sidecar-shutdown-timeout SECONDS is "
"consumed by SGLang.",
type_parser=json_list_type,
),
NS("serving"),
] = None
skip_server_warmup: A[bool, "If set, skip warmup.", NS("serving")] = False
warmups: A[
Optional[str],
"Specify custom warmup functions (csv) to run before server starts eg. --warmups=warmup_name1,warmup_name2 will run the functions `warmup_name1` and `warmup_name2` specified in warmup.py before the server starts listening for requests",
NS("serving"),
] = None
enable_http2: A[
bool,
"Use Granian instead of Uvicorn as the ASGI server, enabling HTTP/1.1 and HTTP/2 auto-negotiation. Clients may use h2c (cleartext HTTP/2) or plain HTTP/1.1. Requires 'pip install sglang[http2]'.",
NS("serving"),
] = False
http2_max_concurrent_streams: A[
int,
"Maximum number of concurrent streams advertised on each HTTP/2 "
"connection (1 to 2^32 - 1). Only applies with --enable-http2.",
NS("serving"),
] = 200
http2_initial_connection_window_size: A[
int,
"Initial connection-level HTTP/2 receive window in bytes (1024 to "
"2^31 - 1). Only applies with --enable-http2.",
NS("serving"),
] = 1024 * 1024
# -------------------------------------------------------------------------
# SSL/TLS
# -------------------------------------------------------------------------
ssl_keyfile: A[
Optional[str], "The file path to the SSL key file.", NS("serving")
] = None
ssl_certfile: A[
Optional[str], "The file path to the SSL certificate file.", NS("serving")
] = None
ssl_ca_certs: A[Optional[str], "The CA certificates file.", NS("serving")] = None
ssl_keyfile_password: A[
Optional[str], "The password to decrypt the SSL keyfile.", NS("serving")
] = None
enable_ssl_refresh: A[
bool,
"Enable automatic SSL certificate hot-reloading when cert/key files change on disk. Requires --ssl-certfile and --ssl-keyfile.",
NS("serving"),
] = False
# -------------------------------------------------------------------------
# API related
# -------------------------------------------------------------------------
api_key: A[
Optional[str],
"Set API key of the server. It is also used in the OpenAI API compatible server.",
NS("serving"),
] = None
admin_api_key: A[
Optional[str],
"Set admin API key for sensitive management endpoints (e.g. /clear_hicache_storage_backend). When set, admin endpoints require this key and do NOT accept --api-key.",
NS("serving"),
] = None
served_model_name: A[
Optional[str],
"Override the model name returned by the v1/models endpoint in OpenAI API server.",
NS("serving"),
] = None
weight_version: A[
str,
"Version identifier for the model weights. Defaults to 'default' if not specified.",
NS("serving"),
] = "default"
chat_template: A[
Optional[str],
"The buliltin chat template name or the path of the chat template file. This is only used for OpenAI-compatible API server.",
NS("serving"),
] = None
hf_chat_template_name: A[
Optional[str],
"When the HuggingFace tokenizer has multiple chat templates (e.g., 'default', 'tool_use', 'rag'), specify which named template to use. If not set, the first available template is used.",
NS("serving"),
] = None
completion_template: A[
Optional[str],
"The buliltin completion template name or the path of the completion template file. This is only used for OpenAI-compatible API server. only for code completion currently.",
NS("serving"),
] = None
file_storage_path: A[
str, "The path of the file storage in backend.", NS("serving")
] = "sglang_storage"
enable_cache_report: A[
bool,
"Return number of cached tokens in usage.prompt_tokens_details for each openai request.",
NS("serving"),
] = False
return_input_ids: A[
bool,
"Return prompt (input) token ids on the response-level sglext extension for every chat completion request, as if return_input_ids_in_sglext were set on the request.",
NS("serving"),
] = False
return_output_ids: A[
bool,
"Return sampled output token ids on the response-level sglext extension for every chat completion request, as if return_output_ids_in_sglext were set on the request.",
NS("serving"),
] = False
reasoning_parser: A[Optional[str], NS("serving")] = None
default_chat_template_kwargs: A[
Optional[Dict[str, Any]],
Arg(
help="Default chat template kwargs applied to every request when not "
"overridden per-request. Keys must match what the model's chat template "
"expects (e.g. enable_thinking, thinking, reasoning_effort). Per-request "
"chat_template_kwargs takes precedence.",
type_parser=json.loads,
),
NS("serving"),
] = None
strip_thinking_cache: A[
bool,
"Skip caching reasoning-model output (thinking + answer) in the radix tree on finish; keep only the prompt prefix. Opt-in: changes cache contents.",
NS("serving"),
] = False
enable_strict_thinking: A[
bool,
"Enable strict token filtering during the thinking phase. Blocks model-specific excluded tokens (e.g., tool call markers) during reasoning. Requires a grammar backend that supports token filtering.",
NS("serving"),
] = False
tool_call_parser: A[Optional[str], NS("serving")] = None
tool_server: A[
Optional[str],
"Either 'demo' or a comma-separated list of tool server urls to use for the model. If not specified, no tool server will be used.",
NS("serving"),
] = None
sampling_defaults: A[
str,
Arg(
help="Where to get default sampling parameters. 'openai' uses SGLang/OpenAI defaults (temperature=1.0, top_p=1.0, etc.). 'model' uses the model's generation_config.json to get the recommended sampling parameters if available. Default is 'model'.",
choices=["openai", "model"],
),
NS("serving"),
] = "model"
asr_max_buffer_seconds: A[
int,
"Maximum seconds of PCM audio the streaming ASR WebSocket handler will accumulate before closing the session with a buffer_overflow error. Guards against OOM when a client streams audio faster than inference can consume it. Default 60s.",
NS("serving"),
] = 60
asr_max_concurrent_sessions: A[
int,
"Maximum number of concurrent realtime ASR WebSocket sessions served by /v1/realtime. New connections beyond this cap are accepted, sent an error{code:too_many_sessions} frame, and closed. Default 32.",
NS("serving"),
] = 32
preferred_sampling_params: A[
Optional[str],
Arg(
help="json-formatted sampling settings that will be returned in /get_model_info",
type_parser=json.loads,
),
NS("serving"),
] = None
allow_auto_truncate: A[
bool,
"Allow automatically truncating requests that exceed the maximum input length instead of returning an error.",
NS("serving"),
] = False
# -------------------------------------------------------------------------
# Streaming
# -------------------------------------------------------------------------
stream_interval: A[
int,
"The interval (or buffer size) for streaming in terms of the token length. A smaller value makes streaming smoother, while a larger value makes the throughput higher",
NS("serving"),
] = 1
batch_notify_size: A[
int,
"Number of streaming notifications to batch before yielding to the event loop. Reduces asyncio wakeup overhead under high concurrency.",
NS("serving"),
] = 16
stream_response_default_include_usage: A[
bool,
"Include usage in every streaming response (even when stream_options is not specified).",
NS("serving"),
] = False
incremental_streaming_output: A[
bool, "Whether to output as a sequence of disjoint segments.", NS("serving")
] = False
enable_streaming_session: A[
bool,
"Enable streaming session mode and StreamingSession wrapper.",
NS("serving"),
] = False
enable_session_radix_cache: A[
bool,
"Track per-session references on UnifiedRadixCache KV: eviction consumes unreferenced entries before referenced ones, and closing a session only dereferences its KV.",
NS("memory"),
] = False
# -------------------------------------------------------------------------
# Logging, metrics, and tracing
# -------------------------------------------------------------------------
log_level: A[str, "The logging level of all loggers.", NS("observability")] = "info"
log_level_http: A[
Optional[str],
"The logging level of HTTP server. If not set, reuse --log-level by default.",
NS("observability"),
] = None
log_requests: A[
bool,
"Log metadata, inputs, outputs of all requests. The verbosity is decided by --log-requests-level",
NS("observability"),
] = False
log_requests_level: A[
int,
Arg(
help="0: Log metadata (no sampling parameters). 1: Log metadata and sampling parameters. 2: Log metadata, sampling parameters and partial input/output. 3: Log every input/output.",
choices=[0, 1, 2, 3],
),
NS("observability"),
] = 2
log_requests_format: A[
str,
Arg(
help="Format for request logging: 'text' (human-readable) or 'json' (structured)",
choices=["text", "json"],
),
NS("observability"),
] = "text"
log_requests_target: A[
Optional[List[str]],
"Target(s) for request logging: 'stdout' and/or directory path(s) for file output. Can specify multiple targets, e.g., '--log-requests-target stdout /my/path'. ",
NS("observability"),
] = None
uvicorn_access_log_exclude_prefixes: A[
List[str],
Arg(
help="Exclude uvicorn access logs whose request path starts with any of these prefixes. Defaults to empty (disabled). Example: --uvicorn-access-log-exclude-prefixes /metrics /health",
nargs="*",
),
NS("observability"),
] = dataclasses.field(default_factory=list)
crash_dump_folder: A[
Optional[str],
"Folder path to dump requests from the last 5 min before a crash (if any). If not specified, crash dumping is disabled.",
NS("observability"),
] = None
show_time_cost: A[bool, "Show time cost of custom marks.", NS("observability")] = (
False
)
enable_metrics: A[bool, "Enable log prometheus metrics.", NS("observability")] = (
False
)
smg_http_sidecar_port: A[
Optional[int],
Arg(
help="Port for the HTTP sidecar server in legacy SMG gRPC mode (--smg-grpc-mode). Serves Prometheus metrics and profiling endpoints. Defaults to --port + 1. Not used in HTTP mode.",
aliases=["--grpc-http-sidecar-port"],
),
NS("observability"),
] = None
enable_mfu_metrics: A[
bool, "Enable estimated MFU-related prometheus metrics.", NS("observability")
] = False
enable_metrics_for_all_schedulers: A[
bool,
"Enable --enable-metrics-for-all-schedulers when you want schedulers on all TP ranks (not just TP 0) to record request metrics separately. This is especially useful when dp_attention is enabled, as otherwise all metrics appear to come from TP 0.",
NS("observability"),
] = False
load_snapshot_publish_interval: A[
int,
"Publish load snapshot to shared memory every N decode iterations. Prefill and idle always publish immediately.",
NS("observability"),
] = 15
tokenizer_metrics_custom_labels_header: A[
str,
"Specify the HTTP header for passing custom labels for tokenizer metrics.",
NS("observability"),
] = "x-custom-labels"
tokenizer_metrics_allowed_custom_labels: A[
Optional[List[str]],
"The custom labels allowed for tokenizer metrics. The labels are specified via a dict in '--tokenizer-metrics-custom-labels-header' field in HTTP requests, e.g., {'label1': 'value1', 'label2': 'value2'} is allowed if '--tokenizer-metrics-allowed-custom-labels label1 label2' is set.",
NS("observability"),
] = None
extra_metric_labels: A[
Optional[Dict[str, str]],
Arg(
help='The custom labels for metrics. e.g. \'{"label1": "value1", "label2": "value2"}\'',
type_parser=json.loads,
),
NS("observability"),
] = None
bucket_time_to_first_token: A[
Optional[List[float]],
"The buckets of time to first token, specified as a list of floats.",
NS("observability"),
] = None
bucket_inter_token_latency: A[
Optional[List[float]],
"The buckets of inter-token latency, specified as a list of floats.",
NS("observability"),
] = None
bucket_e2e_request_latency: A[
Optional[List[float]],
"The buckets of end-to-end request latency, specified as a list of floats.",
NS("observability"),
] = None
prompt_tokens_buckets: A[
Optional[List[str]],
"The buckets rule of prompt tokens. "
"Supports 3 rule types: 'default' uses predefined buckets; 'tse <middle> <base> <count>' "
"generates two sides exponential distributed buckets (e.g., 'tse 1000 2 8' generates buckets "
"[984.0, 992.0, 996.0, 998.0, 1000.0, 1002.0, 1004.0, 1008.0, 1016.0]).); 'custom <value1> "
"<value2> ...' uses custom bucket values (e.g., 'custom 10 50 100 500').",
NS("observability"),
] = None
generation_tokens_buckets: A[
Optional[List[str]],
"The buckets rule for generation tokens histogram. "
"Supports 3 rule types: 'default' uses predefined buckets; 'tse <middle> <base> <count>' "
"generates two sides exponential distributed buckets (e.g., 'tse 1000 2 8' generates buckets "
"[984.0, 992.0, 996.0, 998.0, 1000.0, 1002.0, 1004.0, 1008.0, 1016.0]).); 'custom <value1> "
"<value2> ...' uses custom bucket values (e.g., 'custom 10 50 100 500').",
NS("observability"),
] = None
gc_warning_threshold_secs: A[
float,
"The threshold for long GC warning. If a GC takes longer than this, a warning will be logged. Set to 0 to disable.",
NS("observability"),
] = 0.0
decode_log_interval: A[
int,
"The log and metrics reporting interval (in decode iterations) for decode batches.",
NS("observability"),
] = 40
enable_request_time_stats_logging: A[
bool, "Enable per request time stats logging", NS("observability")
] = False
kv_events_config: A[
Optional[str],
"Config in json format for NVIDIA dynamo KV event publishing. Publishing will be enabled if this flag is used. Runtime-load publishing for load-aware routers is a separate opt-in; see --load-publish-endpoint.",
NS("observability"),
] = None
load_publish_endpoint: A[
Optional[str],
"Opt in to the runtime-load PUB socket that load-aware routers subscribe to. Off by default (unset or 'off'). Use 'auto' to reserve the dp_size ports packed after the --kv-events-config range, or a wildcard-host TCP address (e.g. tcp://*:6000) to place it explicitly; rank r binds port+r and /server_info advertises the base under the kv_events block. Requires --kv-events-config to describe a publisher (routers discover the base through /server_info); startup fails if this is set without one, is not bindable, or overlaps the KV range. Note: 'auto' reserves 2*dp_size ports from the KV base — space co-hosted engines accordingly. The router-facing update cadence follows --load-snapshot-publish-interval (shared to avoid double-collecting the snapshot), so a large value there also staleness-caps this feed.",
NS("observability"),
] = None
enable_forward_pass_metrics: A[
bool,
"Enable per-iteration forward pass metrics via ZMQ IPC. External consumers (e.g. Dynamo planner) subscribe to the IPC endpoint exposed in server_args.forward_pass_metrics_ipc_name.",
NS("observability"),
] = False
forward_pass_metrics_worker_id: A[
str, Arg(help=argparse.SUPPRESS), NS("observability")
] = ""
forward_pass_metrics_ipc_name: A[
Optional[str], Arg(help=argparse.SUPPRESS), NS("observability")
] = None
enable_trace: A[bool, "Enable opentelemetry trace", NS("observability")] = False
trace_modules: A[
str,
"Select the components to trace. Available options are 'request' and 'mooncake'. Format: <module1 name>,<module2 name>,...",
NS("observability"),
] = "request"
otlp_traces_endpoint: A[
str,
"Config opentelemetry collector endpoint if --enable-trace is set. format: <ip>:<port>",
NS("observability"),
] = "localhost:4317"
# RequestMetricsExporter configuration
export_metrics_to_file: A[
bool,
"Export performance metrics for each request to local file (e.g. for forwarding to external systems).",
NS("observability"),
] = False
export_metrics_to_file_dir: A[
Optional[str],
"Directory path for writing performance metrics files (required when --export-metrics-to-file is enabled).",
NS("observability"),
] = None
# Class-level DI for the five *MetricsCollector classes. Maps collector role
# (one of: "scheduler", "tokenizer", "storage", "radix_cache", "expert_dispatch")
# to a subclass of the matching base collector. The five instantiation sites
# read from this map and fall back to the base class. Class-object only (no
# CLI surface) since this exists for embedded use cases that pass a Python
# class directly. Default None preserves existing behavior.
stat_loggers: A[Optional[Dict[str, type]], NS("observability")] = None
# -------------------------------------------------------------------------
# Constrained decoding
# -------------------------------------------------------------------------
constrained_json_whitespace_pattern: A[
Optional[str],
"(outlines and llguidance backends only) Regex pattern for syntactic whitespaces allowed in JSON constrained output. For example, to allow the model generate consecutive whitespaces, set the pattern to [\n\t ]*",
NS("serving"),
] = None
constrained_json_disable_any_whitespace: A[
bool,
"(xgrammar and llguidance backends only) Enforce compact representation in JSON constrained output.",
NS("serving"),
] = False
# -------------------------------------------------------------------------
# Kernel backend
# -------------------------------------------------------------------------
attention_backend: A[
Optional[str],
Arg(
help="Choose the kernels for attention layers.",
choices=ATTENTION_BACKEND_CHOICES,
resolvable=True,
),
NS("exec.kernel"),
] = None
decode_attention_backend: A[
Optional[str],
Arg(
help="Choose the kernels for decode attention layers (have priority over --attention-backend).",
choices=ATTENTION_BACKEND_CHOICES,
resolvable=True,
),
NS("exec.kernel"),
] = None
enable_lean_attention: A[
Optional[bool],
"Enable Lean (Work-Centric) Attention decode kernel for long-context serving. When None (default), uses auto-gate that activates Lean for long contexts and falls back to standard kernel for short contexts. Set to True to force enable, False to force disable.",
NS("exec.kernel"),
] = None
prefill_attention_backend: A[
Optional[str],
Arg(
help="Choose the kernels for prefill attention layers (have priority over --attention-backend).",
choices=ATTENTION_BACKEND_CHOICES,
resolvable=True,
),
NS("exec.kernel"),
] = None
sampling_backend: A[
Optional[str],
Arg(
help="Choose the kernels for sampling layers.",
no_cli=True,
resolvable=True,
),
NS("exec.kernel"),
] = None
grammar_backend: A[
Optional[str],
Arg(
help="Choose the backend for grammar-guided decoding.",
choices=GRAMMAR_BACKEND_CHOICES,
),
NS("exec.kernel"),
] = None
radix_cache_backend: A[
Optional[str],
"Name of a radix-cache backend previously registered via register_radix_cache_backend. Omit this flag to use the built-in default cache selection chain.",
NS("memory"),
] = None
mm_attention_backend: A[
Optional[str],
Arg(
help="Set multimodal attention backend.",
choices=[
"sdpa",
"fa3",
"fa4",
"triton_attn",
"ascend_attn",
"aiter_attn",
"flashinfer_cudnn",
"amx_attn",
"xpu_attn",
],
),
NS("mm"),
] = None
fp8_gemm_runner_backend: A[
str,
Arg(
help="Choose the runner backend for Blockwise FP8 GEMM operations. Options: 'auto' (default, auto-selects based on hardware; MXFP8 dense picks flashinfer_cutedsl on SM100/SM103 and FlashInfer CUTLASS on other supported Blackwell GPUs), 'deep_gemm' (JIT-compiled; enabled by default on NVIDIA Hopper (SM90) and Blackwell (SM100) when DeepGEMM is installed), 'flashinfer_trtllm' (optimal for Blackwell and low-latency), 'flashinfer_cutlass' (FlashInfer CUTLASS groupwise FP8 GEMM), 'flashinfer_cutedsl' (FlashInfer CuTe DSL MXFP8 GEMM on SM100/SM103), 'flashinfer_deepgemm' (Hopper SM90 only; uses swapAB optimization for small M dimensions in decoding), 'cutlass' (optimal for SM120 GPUs), 'triton' (fallback, widely compatible), 'aiter' (ROCm only). ",
cli_name="--fp8-gemm-backend",
choices=FP8_GEMM_RUNNER_BACKEND_CHOICES,
resolvable=True,
),
NS("exec.kernel"),
] = "auto"
fp4_gemm_runner_backend: A[
str,
Arg(
help="Choose the runner backend for NVFP4 GEMM operations. Options: 'auto' (default; selects flashinfer_cutedsl on SM100, marlin on SM80-SM90, flashinfer_cutlass otherwise (including SM120)), 'flashinfer_cutlass' (FlashInfer CUTLASS backend), 'flashinfer_cudnn' (FlashInfer cuDNN backend, optimal on CUDA 13+ with cuDNN 9.15+), 'flashinfer_cutedsl' (FlashInfer CuTe DSL backend), 'flashinfer_trtllm' (FlashInfer TensorRT-LLM backend, requires different weight preparation with shuffling), 'marlin' (weight-only W4A16 fallback for SM80+). ",
cli_name="--fp4-gemm-backend",
choices=FP4_GEMM_RUNNER_BACKEND_CHOICES,
resolvable=True,
),
NS("exec.kernel"),
] = "auto"
bf16_gemm_backend: A[
str,
Arg(
help="Choose the backend for unquantized BF16 GEMM operations. Options: 'auto' (default; selects 'cutedsl' on SM10x GPUs, except deterministic inference selects 'torch'; otherwise uses cuBLAS via torch.nn.functional.linear), 'cutedsl' (SGLang JIT CuTe DSL TGV BF16 GEMM on SM10x; dispatches between the allowlisted low-M Split-K kernel, the CuTe DSL kernel, and cuBLAS; set SGLANG_ENABLE_BF16_SPLITK_GEMM=0 to disable Split-K), 'flashinfer_pr4266' (legacy compatibility alias for the optimized CuTe DSL path), 'gemv', 'torch' (always uses cuBLAS via torch.nn.functional.linear).",
cli_name="--bf16-gemm-backend",
choices=["auto", "cutedsl", "flashinfer_pr4266", "gemv", "torch"],
),
NS("exec.kernel"),
] = "auto"
dsa_prefill_backend: A[
Optional[str],
Arg(
help="DSA (DeepSeek Sparse Attention) prefill backend. If not specified, auto-detects based on hardware and kv_cache_dtype.",
choices=[
"flashmla_sparse",
"flashmla_sparse_q8",
"flashmla_kv",
"flashmla_auto",
"flashinfer_sparse_mla",
"fa3",
"tilelang",
"aiter",
"trtllm",
],
resolvable=True,
),
NS("exec.kernel"),
] = None
dsv4_prefill_backend: A[
str,
Arg(
help=(
"DeepSeek-V4 sparse prefill backend. 'auto' and "
"'flashmla_sparse' use the existing BF16 sparse prefill path; "
"'flashmla_sparse_q8' enables the Q8KV8 sparse prefill path."
),
choices=["auto", "flashmla_sparse", "flashmla_sparse_q8"],
),
NS("exec.kernel"),
] = "auto"
dsa_decode_backend: A[
Optional[str],
Arg(
help="DSA (DeepSeek Sparse Attention) decode backend. If not specified, auto-detects based on hardware and kv_cache_dtype.",
choices=[
"flashmla_sparse",
"flashmla_sparse_q8",
"flashmla_kv",
"flashmla_auto",
"flashinfer_sparse_mla",
"fa3",
"tilelang",
"aiter",
"trtllm",
],
resolvable=True,
),
NS("exec.kernel"),
] = None
dsa_paged_mqa_logits_backend: A[
str,
Arg(
help="DSA indexer paged MQA logits kernel backend. Options: 'auto' (default; DeepGEMM on CUDA, aiter on ROCm), 'deepgemm', 'cutedsl' (CuTe DSL kernel, SM 100 (Blackwell) only; wins at low batch size and long context), 'aiter' (ROCm only).",
choices=["auto", "deepgemm", "cutedsl", "aiter"],
),
NS("exec.kernel"),
] = "auto"
dsa_topk_backend: A[
str,
Arg(
help="DSA indexer top-k backend for the target model. Options: 'sgl-kernel', 'torch', 'flashinfer'. The 'torch' backend currently requires SGLANG_DSA_FUSE_TOPK=false.",
choices=["sgl-kernel", "torch", "flashinfer"],
),
NS("exec.kernel"),
] = "sgl-kernel"
disable_flashinfer_autotune: A[
bool, "Disable FlashInfer autotuning.", NS("exec.kernel")
] = False
flashinfer_autotune_skip_ops: A[
Optional[List[str]],
Arg(
help=(
"FlashInfer custom-op identifiers to skip during autotuning. "
"Skipped ops use FlashInfer's heuristic fallback. SGLang "
"temporarily skips mxfp8_gemm by default due to an IMA."
),
nargs="+",
),
NS("exec.kernel"),
] = None
mamba_backend: A[
str,
Arg(
help="Choose the kernel backend for Mamba SSM operations. Default is 'triton'. Options: 'triton' (default), 'flashinfer' (requires FlashInfer with Mamba support).",
choices=["triton", "flashinfer"],
),
NS("exec.mamba"),
] = "triton"
# -------------------------------------------------------------------------
# Cuda graphs
# -------------------------------------------------------------------------
cuda_graph_config: A[
Optional[CudaGraphConfig],
Arg(
help='Per-phase CUDA graph settings as JSON, e.g. \'{"decode":{"backend":"full","max_bs":256},"prefill":{"backend":"tc_piecewise","tc_compiler":"eager"}}\'. Allowed backends per phase: full, breakable, tc_piecewise, disabled (full is decode-only). JSON wins over the per-phase --cuda-graph-* convenience flags and over legacy flags.',
type_parser=parse_cuda_graph_config_arg,
),
NS("exec.graph"),
] = None
cuda_graph_backend_decode: A[
Optional[Literal["full", "breakable", "tc_piecewise", "disabled"]],
Arg(
help="Backend for the decode phase. Folds into cuda_graph_config[decode].backend.",
choices=Backend.ALL,
),
NS("exec.graph"),
] = None
cuda_graph_backend_prefill: A[
Optional[Literal["full", "breakable", "tc_piecewise", "disabled"]],
Arg(
help="Backend for the prefill phase. Folds into cuda_graph_config[prefill].backend.",
choices=Backend.ALL,
),
NS("exec.graph"),
] = None
cuda_graph_max_bs_decode: A[
Optional[int],
"Maximum batch size captured for the decode cuda graph.",
NS("exec.graph"),
] = None
cuda_graph_max_bs_prefill: A[
Optional[int],
"Maximum batch size captured for the prefill cuda graph.",
NS("exec.graph"),
] = None
cuda_graph_bs_decode: A[
Optional[List[int]],
"Explicit list of batch sizes to capture for the decode cuda graph.",
NS("exec.graph"),
] = None
cuda_graph_bs_prefill: A[
Optional[List[int]],
"Explicit list of batch sizes to capture for the prefill cuda graph.",
NS("exec.graph"),
] = None
cuda_graph_tc_compiler: A[
Optional[Literal["eager", "inductor"]],
"Compiler used by the tc_piecewise backend (currently only the prefill phase consumes it).",
NS("exec.graph"),
] = None
disable_prefill_cuda_graph: A[
bool,
"Disable the prefill-phase CUDA graph. Convenience for --cuda-graph-backend-prefill=disabled.",
NS("exec.graph"),
] = False
disable_decode_cuda_graph: A[
bool,
"Disable the decode-phase CUDA graph. Convenience for --cuda-graph-backend-decode=disabled.",
NS("exec.graph"),
] = False
disable_cuda_graph: A[bool, Arg(no_cli=True), NS("exec.graph")] = False
disable_cuda_graph_padding: A[
bool,
"Disable cuda graph when padding is needed. Still uses cuda graph when padding is not needed.",
NS("exec.graph"),
] = False
enable_profile_cuda_graph: A[
bool, "Enable profiling of cuda graph capture.", NS("exec.graph")
] = False
enable_cudagraph_gc: A[
bool,
"Enable garbage collection during CUDA graph capture. If disabled (default), GC is frozen during capture to speed up the process.",
NS("exec.graph"),
] = False
debug_cuda_graph: A[
bool,
"Enable debug/eager mode for CUDA graph using breakable CUDA graph. When enabled, graph breaks are inserted so every operation runs eagerly while still going through the CUDA graph capture / replay path. Useful for debugging CUDA graph capture / replay issues.",
NS("exec.graph"),
] = False
# -------------------------------------------------------------------------
# Communication and kernels
# -------------------------------------------------------------------------
enable_layerwise_nvtx_marker: A[
bool,
"Enable layerwise NVTX profiling annotations for the model.",
NS("exec.comm"),
] = False
enable_nccl_nvls: A[
bool,
"Enable NCCL NVLS for prefill heavy requests when available.",
NS("exec.comm"),
] = False
enable_symm_mem: A[
bool,
Arg(
help="Enable NCCL symmetric memory for fast collectives.",
resolvable=True,
),
NS("exec.comm"),
] = False
triton_attention_reduce_in_fp32: A[
bool,
"Cast the intermediate attention results to fp32 to avoid possible crashes related to fp16."
"This only affects Triton attention kernels.",
NS("exec.kernel"),
] = False
triton_attention_num_kv_splits: A[
int,
"The number of KV splits in flash decoding Triton kernel. Larger value is better in longer context scenarios. The default value is 8.",
NS("exec.kernel"),
] = 8
triton_attention_split_tile_size: A[
Optional[int],
"The size of split KV tile in flash decoding Triton kernel. Used for deterministic inference.",
NS("exec.kernel"),
] = None
flashinfer_mla_disable_ragged: A[
bool,
"Not using ragged prefill wrapper when running flashinfer mla",
NS("exec.kernel"),
] = False
enable_fused_qk_norm_rope: A[
bool,
"Enable fused qk normalization and rope rotary embedding.",
NS("exec.kernel"),
] = False
enable_precise_embedding_interpolation: A[
bool,
"Enable corner alignment for resize of embeddings grid to ensure more accurate(but slower) evaluation of interpolated embedding values.",
NS("exec.kernel"),
] = False
enable_fused_moe_sum_all_reduce: A[
bool, "Enable fused moe triton and sum all reduce.", NS("exec.moe")
] = False
enable_deepseek_v4_fp4_indexer: A[
bool,
"Enable the experimental FP4 C4 indexer path for DeepSeek V4. Default keeps the existing indexer implementation.",
NS("exec.kernel"),
] = False
disable_custom_all_reduce: A[
bool,
Arg(
help="Disable the custom all-reduce kernel and fall back to NCCL.",
resolvable=True,
),
NS("exec.comm"),
] = False
enable_mscclpp: A[
bool,
"Enable using mscclpp for small messages for all-reduce kernel and fall back to NCCL.",
NS("exec.comm"),
] = False
enable_torch_symm_mem: A[
bool,
"Enable using torch symm mem for all-reduce kernel and fall back to NCCL. Only supports CUDA device SM90 and above. SM90 supports world size 4, 6, 8. SM100 supports world size 6, 8.",
NS("exec.comm"),
] = False
enable_scattered_sconv: A[
bool,
"Inkling: replace the attention/MLP output all-reduce with a hidden-dimension reduce-scatter, run the channelwise output short convolution on the [T, H/P] shard, then all-gather before the residual add. This shards the convolution cache across tensor-parallel ranks without changing communication volume.",
NS("exec.comm"),
] = False
pre_warm_nccl: A[
bool,
"Pre-warm NCCL/RCCL communicators during startup to reduce P99 TTFT cold-start latency. Default: enabled for AMD/HIP (RCCL), disabled for NVIDIA/CUDA (NCCL).",
NS("exec.comm"),
] = False
enable_quant_communications: A[
Optional[bool],
"Enable INT8 quantization of TP communications (limited support).",
NS("exec.comm"),
] = False
enable_flashinfer_allreduce_fusion: A[bool, Arg(no_cli=True), NS("exec.comm")] = (
False
)
enforce_disable_flashinfer_allreduce_fusion: A[
bool, "Enforce disable FlashInfer allreduce fusion.", NS("exec.comm")
] = False
flashinfer_allreduce_fusion_backend: A[
Optional[Literal["auto", "trtllm", "mnnvl"]],
Arg(
help=(
"Enable FlashInfer allreduce fusion and choose backend. "
"Requires SM90 or SM10X NVIDIA GPUs. "
"Defaults to auto. "
"'auto': choose mnnvl on Blackwell (SM100/SM103) systems "
"(single- and multi-node) and trtllm on SM90 single-node systems. "
"'trtllm': available on single-node systems only. "
"'mnnvl': available on SM90 single-node systems and SM100/SM103 "
"single-node or multi-node systems via MNNVL fabric. "
"Fuses allreduce with Residual + RMSNorm for supported MoE models."
),
resolvable=True,
),
NS("exec.comm"),
] = None
enable_aiter_allreduce_fusion: A[
bool,
Arg(help="Enable Aiter AllReduce Fusion.", resolvable=True),
NS("exec.comm"),
] = False
# -------------------------------------------------------------------------
# Torch compile
# -------------------------------------------------------------------------
enable_torch_compile: A[
bool,
"Optimize the model with torch.compile. Experimental feature.",
NS("exec.graph"),
] = False
enable_torch_compile_debug_mode: A[
bool, "Enable debug mode for torch compile", NS("exec.graph")
] = False
torch_compile_max_bs: A[
int, "Set the maximum batch size when using torch compile.", NS("exec.graph")
] = 32
# -------------------------------------------------------------------------
# Speculative decoding
# -------------------------------------------------------------------------
speculative_algorithm: A[
Optional[str],
"Speculative algorithm. Builtins: EAGLE, EAGLE3, NEXTN, STANDALONE, NGRAM, DFLASH, DSPARK, UNO. Or any name registered via `SpeculativeAlgorithm.register`.",
NS("spec"),
] = None
uno_lora_path: A[
Optional[str],
"Path to the UNO draft LoRA checkpoint.",
NS("spec"),
] = None
speculative_draft_model_path: A[
Optional[str],
Arg(
help="The path of the draft model weights. This can be a local folder or a Hugging Face repo ID.",
aliases=["--speculative-draft-model"],
),
NS("spec"),
] = None
speculative_draft_model_revision: A[
Optional[str],
"The specific draft model version to use. It can be a branch name, a tag name, or a commit id. If unspecified, will use the default version.",
NS("spec"),
] = None
speculative_draft_load_format: A[
Optional[str],
Arg(
help="The format of the draft model weights to load. If not specified, will use the same format as --load-format. Use 'dummy' to initialize draft model weights with random values for profiling.",
choices=LOAD_FORMAT_CHOICES,
),
NS("spec"),
] = None
speculative_num_steps: A[
Optional[int],
"The number of steps sampled from draft model in Speculative Decoding.",
NS("spec"),
] = None
speculative_eagle_topk: A[
Optional[int],
"The number of tokens sampled from the draft model in eagle2 each step.",
NS("spec"),
] = None
speculative_num_draft_tokens: A[
Optional[int],
"The number of tokens sampled from the draft model in Speculative Decoding.",
NS("spec"),
] = None
speculative_dflash_block_size: A[
Optional[int],
"DFLASH only. Block size (verify window length). Alias of --speculative-num-draft-tokens for DFLASH.",
NS("spec"),
] = None
speculative_dspark_block_size: A[
Optional[int],
"DSPARK only. Draft block size gamma (number of proposed draft tokens). The verify window is gamma + 1, so this sets --speculative-num-draft-tokens = gamma + 1. Omit to auto-infer gamma from the draft checkpoint block_size.",
NS("spec"),
] = None
speculative_dspark_sps_table_path: A[
Optional[str],
"DSPARK only. Path to a pre-profiled SPS cost table (JSON) built offline with "
"sglang.benchmark.dspark_sps_profiler, consumed by the ragged-verify "
"scheduler (cap-accept / compact). Omit for an uninitialized flat "
"constant-SPS table: the budget degenerates to verify-all (zero throughput "
"gain by itself).",
NS("spec"),
] = None
speculative_dspark_confidence_sts_path: A[
Optional[str],
"DSPARK only. Optional path to a per-position STS (sequential temperature "
"scaling) calibration JSON, fit offline with sglang.benchmark.dspark_sts_fit. "
"Calibrates the confidence-head survival probabilities the ragged-verify "
"scheduler consumes. Omit to use identity (no calibration); losslessness is "
"unaffected either way.",
NS("spec"),
] = None
speculative_dspark_align_verify_tokens_to_graph_tier: A[
bool,
"DSPARK compact ragged-verify only. Fill the per-request verify lengths so "
"the total verify-token count reaches the cuda-graph tier the forward is "
"already padded to: round the dp-max scheduled total up to the captured "
"token bucket and let the top-k allocator admit that many real draft tokens "
"(confidence-ordered). This recovers the padding the forward pays for anyway "
"-- both the cuda-graph bucket round-up and the dp cross-rank max -- turning "
"it into extra real verification at the same step time. Off by default; when "
"off the schedule is byte-for-byte unchanged.",
NS("spec"),
] = False
speculative_accept_threshold_single: A[
float,
"Accept a draft token if its probability in the target model is greater than this threshold.",
NS("spec"),
] = 1.0
speculative_accept_threshold_acc: A[
float,
"The accept probability of a draft token is raised from its target probability p to min(1, p / threshold_acc).",
NS("spec"),
] = 1.0
speculative_use_rejection_sampling: A[
bool,
"Use rejection sampling for speculative decoding (requires topk=1).",
NS("spec"),
] = False
speculative_token_map: A[
Optional[str], "The path of the draft model's small vocab table.", NS("spec")
] = None
speculative_attention_mode: A[
str,
Arg(
help="Attention backend for speculative decoding operations (both target verify and draft extend). Can be one of 'prefill' (default) or 'decode'.",
choices=["prefill", "decode"],
resolvable=True,
),
NS("spec"),
] = "prefill"
speculative_draft_attention_backend: A[
Optional[str],
Arg(
help="Attention backend for speculative decoding drafting.",
resolvable=True,
),
NS("spec"),
] = None
speculative_dsa_topk_backend: A[
str,
Arg(
help="DSA indexer top-k backend for speculative draft workers. Options: 'sgl-kernel', 'torch', 'flashinfer'. The 'torch' backend currently requires SGLANG_DSA_FUSE_TOPK=false.",
choices=["sgl-kernel", "torch", "flashinfer"],
),
NS("spec"),
] = "sgl-kernel"
speculative_draft_kv_cache_dtype: A[
Optional[str],
Arg(
help="KV cache dtype for the speculative draft model only. The draft pool is "
"allocated with one slot per target token (draft and target share a slot index "
"space), so for a small draft it can still rival the target pool: a 5-layer "
"DFLASH draft costs 10240 bytes/token in bf16. Setting fp8_e4m3 halves the draft "
"pool; the saving shows up as free device memory, so raise "
"--mem-fraction-static to convert it into KV capacity. Default follows "
"--kv-cache-dtype.",
choices=["auto", "fp8_e5m2", "fp8_e4m3", "bf16", "bfloat16"],
),
NS("spec"),
] = None
speculative_draft_window_size: A[
Optional[int],
"Sliding window size for the draft model. Honored by Llama EAGLE-3 (`LlamaForCausalLMEagle3`) and DFLASH only; other EAGLE-3 backends (e.g. MLA-based drafters) silently ignore it. For Llama EAGLE-3, the drafter only attends to the most recent N keys (verifier hidden states + its own outputs); the verifier is unaffected. For DFLASH, the draft worker keeps a recent target-token window in its local KV cache (paged backends may retain up to one extra page on the left for alignment). Default is full attention/context.",
NS("spec"),
] = None
speculative_moe_runner_backend: A[
Optional[str],
Arg(
help="Choose the runner backend for MoE in speculative decoding.",
choices=MOE_RUNNER_BACKEND_CHOICES,
resolvable=True,
),
NS("spec"),
] = None
speculative_moe_a2a_backend: A[
Optional[str],
Arg(
help="Choose the backend for MoE A2A in speculative decoding",
choices=[
"none",
"deepep",
"mooncake",
"nixl",
"mori",
"ascend_fuseep",
"flashinfer",
"megamoe",
"deepep_v2",
"pplx",
"ascend_tp",
],
resolvable=True,
),
NS("spec"),
] = None
speculative_draft_model_quantization: A[
Optional[str],
Arg(
help="The quantization method for speculative model.",
choices=QUANTIZATION_CHOICES,
),
NS("spec"),
] = None
# Internal provenance used after the public draft quantization inherits the
# target value. It is a dataclass field so ServerArgs round-trips preserve
# whether the user explicitly set the draft option; it has no CLI surface.
_speculative_draft_quantization_explicitly_set: A[
Optional[bool], Arg(no_cli=True), NS("spec")
] = None
speculative_skip_dp_mlp_sync: A[
bool,
"Skip the extra MLP sync that the scheduler performs before merging a new batch when speculative decoding + DP attention are both enabled.",
NS("spec"),
] = False
enable_multi_layer_eagle: A[
bool,
Arg(
help="Enable multi-layer Eagle speculative decoding.",
resolvable=True,
),
NS("spec"),
] = False
speculative_adaptive: A[
bool,
"Enable adaptive speculative decoding that dynamically adjusts num_steps based on acceptance rate.",
NS("spec"),
] = False
speculative_adaptive_config: A[
Optional[str],
"Path to a JSON config file for adaptive speculative decoding tuning knobs.",
NS("spec"),
] = None
# Decoupled speculative decoding: draft and verify run as
# separate engines, currently connected by a ZMQ IPC mesh.
decoupled_spec_bind_endpoint: A[
Optional[str],
"ZMQ endpoint this engine binds for its inbound channel in decoupled "
"speculative decoding (verifier: result PULL; drafter: control PULL).",
NS("disagg"),
] = None
decoupled_spec_connect_endpoints: A[
Optional[List[str]],
Arg(
help="Peer inbound (bind) endpoints to connect to, ordered by peer "
"rank, for decoupled speculative decoding.",
type_parser=json_list_type,
),
NS("disagg"),
] = None
decoupled_spec_rank: A[
Optional[int],
"This engine's rank within its own role space (verifier-rank or "
"drafter-rank) for decoupled speculative decoding.",
NS("disagg"),
] = None
decoupled_spec_role: A[
Literal["null", "verifier", "drafter"],
"Role in decoupled speculative decoding: 'null' disables it, 'verifier' "
"runs the target/verify half, 'drafter' runs the draft half.",
NS("disagg"),
] = "null"
spec_trace_dir: A[
Optional[str],
"Directory to write decoupled speculative decoding trace files.",
NS("spec"),
] = None
# -------------------------------------------------------------------------
# Speculative decoding (ngram)
# -------------------------------------------------------------------------
speculative_ngram_min_bfs_breadth: A[
int,
"The minimum breadth for BFS (Breadth-First Search) in ngram speculative decoding.",
NS("spec"),
] = 1
speculative_ngram_max_bfs_breadth: A[
int,
"The maximum breadth for BFS (Breadth-First Search) in ngram speculative decoding.",
NS("spec"),
] = 10
speculative_ngram_match_type: A[
Literal["BFS", "PROB"], "The match type for cache tree.", NS("spec")
] = "BFS"
speculative_ngram_max_trie_depth: A[
int, "The max trie depth for ngram speculative decoding.", NS("spec")
] = 18
speculative_ngram_capacity: A[
int, "The cache capacity for ngram speculative decoding.", NS("spec")
] = 10 * 1000 * 1000
speculative_ngram_external_corpus_path: A[
Optional[str],
"Path to an external JSONL corpus to pre-load into SAM at startup. Additional corpora can be added at runtime via POST /add_external_corpus.",
NS("spec"),
] = None
speculative_ngram_external_sam_budget: A[
int,
"Number of draft nodes reserved for the external SAM subtree in ngram speculative decoding.",
NS("spec"),
] = 0
speculative_ngram_external_corpus_max_tokens: A[
int,
"Fail startup if the tokenized external ngram corpus exceeds this many tokens. Tune this based on your CPU memory budget.",
NS("spec"),
] = 10000000
# -------------------------------------------------------------------------
# Expert parallelism
# -------------------------------------------------------------------------
ep_size: A[
int,
Arg(
help="The expert parallelism size.",
aliases=["--expert-parallel-size", "--ep"],
resolvable=True,
),
NS("parallel"),
] = 1
moe_a2a_backend: A[
Literal[
"none",
"deepep",
"mooncake",
"nixl",
"mori",
"ascend_fuseep",
"flashinfer",
"megamoe",
"deepep_v2",
"ascend_tp",
"pplx",
],
Arg(
help="Choose the backend for MoE A2A.",
choices=[
"none",
"deepep",
"mooncake",
"nixl",
"mori",
"ascend_fuseep",
"flashinfer",
"megamoe",
"deepep_v2",
"pplx",
"ascend_tp",
],
resolvable=True,
),
NS("exec.moe"),
] = "none"
enable_w4a4_mxfp4_megamoe: A[
bool,
"Enable the W4A4 MXFP4 MegaMoE path with DeepGEMM's "
"mxf4xmxf4 MMA type. Use with "
"--moe-a2a-backend megamoe.",
NS("exec.moe"),
] = False
deepep_v2_mode: A[
Literal["direct", "hybrid"],
"DeepEP v2 ElasticBuffer communication topology, fixed at server init: "
"`direct` (single-node NVLink) or `hybrid` (multi-node scale-out). "
"Layout/grouped-GEMM and the decode CUDA graph are chosen per batch by "
"inference phase, independent of this knob; not equivalent to DeepEP v1 "
"normal/low_latency.",
NS("exec.moe"),
] = "direct"
moe_runner_backend: A[
str,
Arg(
help="Choose the runner backend for MoE.",
choices=MOE_RUNNER_BACKEND_CHOICES,
resolvable=True,
),
NS("exec.moe"),
] = "auto"
flashinfer_mxfp4_moe_precision: A[
Literal["default", "bf16", "fp8"],
"Choose the computation precision of flashinfer mxfp4 moe. "
"On SM90, `fp8` selects the Humming-style MXFP4-weight x FP8-activation "
"path introduced by FlashInfer #3738 and requires FlashInfer >= 0.6.18.",
NS("exec.moe"),
] = "default"
deepep_mode: A[
Literal["auto", "normal", "low_latency"],
"Select the mode when enable DeepEP or MoriEP MoE, could be `normal`, `low_latency` or `auto`. Default is `auto`, which means `low_latency` for decode batch and `normal` for prefill batch.",
NS("exec.moe"),
] = "auto"
fuseep_mode: A[
Literal[1, 2],
"Select the mode when enable Ascend FuseEP MoE, 1 -> dispatch_gmm_combine_decode is executed2 -> dispatch_ffn_combine is executed (support hybrid deployment when 2).",
NS("exec.moe"),
] = 2
deepep_dispatcher_output_dtype: A[
Literal["auto", "bf16", "fp8", "int8", "nvfp4"],
"Select DeepEP dispatcher output dtype",
NS("exec.moe"),
] = "auto"
ep_num_redundant_experts: A[
int,
"Allocate this number of redundant experts in expert parallel.",
NS("exec.moe"),
] = 0
ep_dispatch_algorithm: A[
Optional[Literal["static", "dynamic", "fake", "lp"]],
"The algorithm to choose ranks for redundant experts in expert parallel.",
NS("exec.moe"),
] = None
init_expert_location: A[str, "Initial location of EP experts.", NS("exec.moe")] = (
"trivial"
)
enable_eplb: A[bool, "Enable EPLB algorithm", NS("exec.moe")] = False
eplb_algorithm: A[str, "Chosen EPLB algorithm", NS("exec.moe")] = "auto"
eplb_rebalance_num_iterations: A[
int,
"Number of iterations to automatically trigger a EPLB re-balance.",
NS("exec.moe"),
] = 1000
eplb_rebalance_layers_per_chunk: A[
Optional[int], "Number of layers to rebalance per forward pass.", NS("exec.moe")
] = None
eplb_min_rebalancing_utilization_threshold: A[
float,
"Minimum threshold for GPU average utilization to trigger EPLB rebalancing. Must be in the range [0.0, 1.0].",
NS("exec.moe"),
] = 1.0
expert_distribution_recorder_mode: A[
Optional[Literal["stat", "stat_approx", "per_pass", "per_token"]],
"Mode of expert distribution recorder.",
NS("exec.moe"),
] = None
expert_distribution_recorder_buffer_size: A[
Optional[int],
"Circular buffer size of expert distribution recorder. Set to -1 to denote infinite buffer.",
NS("exec.moe"),
] = None
expert_balancedness_report_mode: A[
Literal["off", "server_log", "prometheus", "both"],
"Where to report expert balancedness. Options: off, server_log, prometheus, both.",
NS("exec.moe"),
] = "off"
deepep_config: A[
Optional[str],
"Tuned DeepEP config suitable for your own cluster. It can be either a string with JSON content or a file path.",
NS("exec.moe"),
] = None
moe_dense_tp_size: A[
Optional[int],
Arg(
help="TP size for MoE dense MLP layers. This flag is useful when, with large TP size, there are errors caused by weights in MLP layers having dimension smaller than the min dimension GEMM supports.",
resolvable=True,
),
NS("parallel"),
] = None
elastic_ep_backend: A[
Literal[None, "mooncake", "nixl"],
Arg(
help="Specify the collective communication backend for elastic EP. Supports 'mooncake' and 'nixl'.",
choices=["none", "mooncake", "nixl"],
),
NS("exec.moe"),
] = None
enable_elastic_expert_backup: A[
bool, "Enable elastic expert backup feature.", NS("exec.moe")
] = False
mooncake_ib_device: A[
Optional[str],
"The InfiniBand devices for Mooncake Backend transfer, accepts multiple comma-separated devices (e.g., --mooncake-ib-device mlx5_0,mlx5_1). Default is None, which triggers automatic device detection when Mooncake Backend is enabled.",
NS("exec.moe"),
] = None
enable_waterfill: A[
bool,
"Enable Waterfill: dispatch the fused shared expert as an extra routed expert slot to the least-loaded EP rank. Supports DeepEP and MegaMOE MoE A2A backends, implicitly enables shared-expert fusion, and supports --deepep-mode auto, normal, or low_latency when used with DeepEP. Use auto or low_latency for production DeepEP decode so CUDA graph remains enabled. Supported on DeepSeek-V3/R1 with EP >= 2.",
NS("exec.moe"),
] = False
ep_join_mode: A[
Optional[Literal["scale", "recover"]],
Arg(
help="Join mode for elastic EP. 'recover' rejoins an existing slot after a fault. 'scale' joins as a new rank beyond the original group size and requires --node-rank 1.",
cli_name="--elastic-ep-join-mode",
choices=["scale", "recover"],
),
NS("exec.moe"),
] = None
ep_join_rank_offset: A[
int,
Arg(
help=(
"Global rank offset of an elastic EP joining group. Scale "
"joiners must set this to the current effective EP size."
),
cli_name="--elastic-ep-join-rank-offset",
),
NS("parallel"),
] = 0
elastic_ep_initial_size: A[
Optional[int],
"EP size used to define the immutable per-rank expert storage layout. "
"Scale joiners must use the primary deployment's launch-time EP size.",
NS("parallel"),
] = None
max_ep_size: A[
Optional[int],
"Maximum EP size the server can scale to at runtime. Pre-allocates active-rank state and backend buffers to this size. Defaults to the launch-time world size.",
NS("parallel"),
] = None
elastic_ep_scale_timeout: A[
float,
"Timeout in seconds for a pending elastic EP scale operation.",
NS("exec.moe"),
] = 600
elastic_ep_rejoin: A[
bool, "[Deprecated] Alias for --elastic-ep-join-mode recover.", NS("exec.moe")
] = False
disable_flashinfer_cutlass_moe_fp4_allgather: A[
bool,
"Disables quantize before all-gather for flashinfer cutlass moe.",
NS("exec.moe"),
] = False
disable_shared_experts_fusion: A[
bool,
Arg(
help="Disable the built-in shared experts fusion optimization for DeepSeek V3/R1. Note: Waterfill (--enable-waterfill) routes the shared expert as an extra MoE slot, so the shared expert is not separated from the MoE path when Waterfill is enabled.",
resolvable=True,
),
NS("exec.moe"),
] = False
enforce_shared_experts_fusion: A[
bool,
"Enforce shared experts fusion even when it would normally be disabled (e.g. under DeepEP). Mutually exclusive with --disable-shared-experts-fusion.",
NS("exec.moe"),
] = False
# -------------------------------------------------------------------------
# Mamba cache and linear attn
# -------------------------------------------------------------------------
max_mamba_cache_size: A[
Optional[int], "The maximum size of the mamba cache.", NS("schedule")
] = None
mamba_ssm_dtype: A[
Optional[str],
Arg(
help="The data type of the SSM states in mamba cache. If not set, will be read from model config (mamba_ssm_dtype).",
choices=["float32", "bfloat16", "float16"],
),
NS("exec.mamba"),
] = None
mamba_max_states_per_path: A[
int,
"Maximum number of cached Mamba states retained per root-to-tail path "
"(-1 means unlimited). When enabled, after each insert the shallowest eligible "
"interior states beyond the cap are removed while their full KV remains. "
"Tail, fork, and locked nodes are preserved. Must be -1 or a positive integer.",
NS("exec.mamba"),
] = -1
enable_mamba_cache_stochastic_rounding: A[
bool,
"Enable stochastic rounding when writing FP16 Mamba SSM cache states. Requires --mamba-ssm-dtype float16 and CUDA. With --mamba-backend triton, requires SM100.",
NS("exec.mamba"),
] = False
mamba_cache_philox_rounds: A[
int,
"Number of Philox rounds to use for stochastic rounding of FP16 Mamba SSM cache writes. Triton uses the Triton default when set to 0; FlashInfer uses 10 rounds when set to 0.",
NS("exec.mamba"),
] = 0
mamba_full_memory_ratio: A[
float,
Arg(
help="The ratio of mamba state memory to full kv cache memory.",
resolvable=True,
),
NS("schedule"),
] = 0.9
mamba_radix_cache_strategy: A[
str,
Arg(
help="The strategy to use for mamba radix cache.",
choices=["auto", "no_buffer", "extra_buffer", "extra_buffer_lazy"],
resolvable=True,
),
NS("exec.mamba"),
] = "auto"
uses_mamba_radix_cache: A[
bool,
Arg(
help="(Derived) whether the model routes through the hybrid-mamba "
"radix cache handling; resolved from the model architecture, no "
"CLI surface.",
no_cli=True,
resolvable=True,
),
NS("exec.mamba"),
] = False
mamba_track_interval: A[
int, "The interval to track the mamba state during decode.", NS("exec.mamba")
] = 256
enable_int8_mamba_checkpoint: A[
bool,
"Store radix-cached linear-attn (mamba) states in int8 (separate checkpoint pool) for ~2x cached-prefix capacity at fixed memory.",
NS("exec.mamba"),
] = False
int8_mamba_ckpt_size: A[
Optional[int],
"Number of int8 mamba checkpoint slots (default: 2x the active mamba pool size).",
NS("exec.mamba"),
] = None
linear_attn_backend: A[
str,
Arg(
help="The default kernel backend for linear attention (GDN/KDA). Can be overridden per-mode by --linear-attn-decode-backend and --linear-attn-prefill-backend. The Helion backend is KDA-only.",
choices=LINEAR_ATTN_KERNEL_BACKEND_CHOICES,
),
NS("exec.mamba"),
] = "triton"
linear_attn_decode_backend: A[
Optional[str],
Arg(
help="Override the kernel backend for linear attention decode. If not set, uses --linear-attn-backend.",
choices=LINEAR_ATTN_KERNEL_BACKEND_CHOICES,
),
NS("exec.mamba"),
] = None
linear_attn_prefill_backend: A[
Optional[str],
Arg(
help="Override the kernel backend for linear attention prefill/extend. If not set, uses --linear-attn-backend; compatible SM100 GDN models may automatically select FlashInfer.",
choices=LINEAR_ATTN_KERNEL_BACKEND_CHOICES,
),
NS("exec.mamba"),
] = None
linear_attn_verify_backend: A[
Optional[str],
Arg(
help="Override the kernel backend for linear attention speculative target-verify. If not set, follows the decode backend (flashinfer decode -> flashinfer verify, otherwise triton). KDA supports triton, nv_cutedsl, and flashinfer verify backends.",
choices=LINEAR_ATTN_KERNEL_BACKEND_CHOICES + ["nv_cutedsl"],
),
NS("exec.mamba"),
] = None
# ReplaySSM buffered output-only linear-attn decode (GDN + KDA): per-slot
# ring + periodic flush to cut per-step HBM state traffic.
enable_linear_replayssm: A[
bool,
"Enable the ReplaySSM buffered output-only linear-attn decode kernel. "
"Primarily a GDN (scalar-gate) decode-bandwidth optimization (~1.2-1.5x "
"at batch >= 64). KDA uses its selected Triton or Helion implementation, "
"but its per-K gate ring is larger and ReplaySSM is typically slower "
"than packed KDA decode; benchmark before enabling it. Requires the "
"Triton linear-attn decode backend, or Helion for KDA, and "
"--mamba-radix-cache-strategy no_buffer (the default).",
NS("exec.mamba"),
] = False
linear_replayssm_cache_len: A[
int,
"Ring-buffer length L for ReplaySSM linear-attn decode. The full recurrent state is flushed to HBM every L decode steps.",
NS("exec.mamba"),
] = 16
# ReplaySSM spec-verify (Part B of RFC #28511): linear-attn target-verify via
# fold-every-commit instead of per-draft full-state snapshots -- the verify
# stores each draft step's raw inputs into a per-slot window and the commit
# replays the accepted prefix into the fp32 checkpoint. GDN sizes the window
# to the draft maximum; KDA folds a (raw v, pre-norm k, gate, beta) ring of
# length --linear-replayssm-cache-len. Linear-chain (topk <= 1) only.
enable_linear_replayssm_spec: A[
bool,
"Enable the ReplaySSM spec-verify: fold-every-commit -- a per-slot raw-input window replaces the recurrent verify's per-draft full-state snapshots. GDN or KDA hybrid linear-attn models, linear-chain (--speculative-eagle-topk in {None, 1}) only.",
NS("exec.mamba"),
] = False
# -------------------------------------------------------------------------
# Hierarchical cache
# -------------------------------------------------------------------------
enable_hierarchical_cache: A[bool, "Enable hierarchical cache", NS("memory")] = (
False
)
hicache_host_memory_mode: A[
str,
Arg(
help="Whether host memory is a persistent HiCache tier (cache) or a transient staging buffer between GPU and the storage backend (buffer_only). buffer_only requires --hicache-storage-backend.",
choices=["cache", "buffer_only"],
),
NS("memory"),
] = "cache"
hicache_ratio: A[
Optional[float],
"The ratio of the size of host KV cache memory pool to the size of device pool. Defaults to 2.0 in cache mode, 1.2 in buffer_only mode, or 0.2 for backup-only host-pool decode retraction.",
NS("memory"),
] = None
hicache_size: A[
int,
"The size of host KV cache memory pool in gigabytes. Overrides --hicache-ratio in either host memory mode.",
NS("memory"),
] = 0
hicache_write_policy: A[
str,
Arg(
help="The write policy of hierarchical cache.",
choices=["write_back", "write_through", "write_through_selective"],
),
NS("memory"),
] = "write_through"
hicache_io_backend: A[
str,
Arg(
help="The IO backend for KV cache transfer between CPU and GPU",
choices=["direct", "kernel", "kernel_ascend"],
),
NS("memory"),
] = "kernel"
hicache_mem_layout: A[
str,
Arg(
help="The layout of host memory pool for hierarchical cache.",
choices=[
"layer_first",
"page_first",
"page_first_direct",
"page_first_kv_split",
"page_head",
],
),
NS("memory"),
] = "page_first"
hicache_storage_backend: A[
Optional[str],
Arg(
help="The storage backend for hierarchical KV cache. Built-in backends: file, mooncake, hf3fs, nixl, aibrix. For dynamic backend, use --hicache-storage-backend-extra-config to specify: backend_name (custom name), module_path (Python module path), class_name (backend class name).",
choices=[
"file",
"sim",
"mooncake",
"hf3fs",
"nixl",
"aibrix",
"dynamic",
"eic",
"simm",
"mori",
"shm",
],
),
NS("memory"),
] = None
hicache_storage_prefetch_policy: A[
str,
Arg(
help="Control when prefetching from the storage backend should stop.",
choices=["best_effort", "wait_complete", "timeout"],
),
NS("memory"),
] = "timeout"
hicache_storage_backend_extra_config: A[
Optional[str],
"A dictionary in JSON string format, or a string starting with a leading '@' and a config file in JSON/YAML/TOML format, containing extra configuration for the storage backend.",
NS("memory"),
] = None
hicache_storage_prefetch_retry_poll_interval: A[
int,
Arg(
help=(
"Scheduling passes a queued request waits after a storage "
"prefetch miss before the availability check is retried "
"(under load the first check can run before the needed "
"backup commits). 0 disables retries."
),
),
NS("memory"),
] = 0
hicache_storage_prefetch_retry_max_attempts: A[
int,
"Maximum storage prefetch retries per request when --hicache-storage-prefetch-retry-poll-interval is set.",
NS("memory"),
] = 4
# -------------------------------------------------------------------------
# Unified Radix Cache
# -------------------------------------------------------------------------
enable_unified_cache_external_linker: A[
bool,
"Link UnifiedRadixCache directly to an external KV store (direct L3), with no host cache tier.",
NS("memory"),
] = False
unified_cache_external_linker_backend: A[
str,
Arg(
help="Storage backend for --enable-unified-cache-external-linker.",
choices=["mooncake", "mori"],
),
NS("memory"),
] = "mooncake"
# -------------------------------------------------------------------------
# Hierarchical sparse attention
# -------------------------------------------------------------------------
enable_hisparse: A[bool, "Enable hierarchical sparse attention", NS("memory")] = (
False
)
hisparse_config: A[
Optional[str],
Arg(
help='A dictionary in JSON string format for hierarchical sparse attention configuration. Example: \'{"top_k": 2048, "device_buffer_size": 4096, "host_to_device_ratio": 2}\'',
aliases=["--hierarchical-sparse-attention-extra-config"],
),
NS("memory"),
] = None
# -------------------------------------------------------------------------
# Multi-modal optimization configs
# -------------------------------------------------------------------------
enable_broadcast_mm_inputs_process: A[
bool, "Enable broadcast mm-inputs process in scheduler.", NS("mm")
] = False
enable_prefix_mm_cache: A[
bool,
"Enable prefix multimodal cache. Currently only supports mm-only.",
NS("mm"),
] = False
mm_enable_dp_encoder: A[
bool,
"Enabling data parallelism for mm encoder. The dp size will be set to the tp size automatically.",
NS("mm"),
] = False
mm_process_config: A[
Optional[Dict[str, Any]],
Arg(
help="Multimodal preprocessing config, a json config contains keys: `image`, `video`, `audio`",
type_parser=json.loads,
),
NS("mm"),
] = None
mm_processor_worker_num: A[
int,
"Number of threads for multimodal processor calls. 0 selects the "
"model-specific default. Only processors with isolated-worker support "
"can use more than one thread.",
NS("mm"),
] = 0
mm_io_worker_num: A[
int,
"Number of threads for multimodal data loading and decoding. 0 selects "
"the model-specific default. SGLANG_IO_WORKERS remains supported as an "
"environment override when this argument is 0.",
NS("mm"),
] = 0
allowed_media_domains: A[
List[str],
"Restrict client-supplied HTTP(S) image, video, and audio URLs to these "
"exact hostnames. Redirect destinations are checked against the same "
"allowlist. When unset, remote media from any domain is allowed.",
NS("mm"),
] = dataclasses.field(default_factory=list)
media_url_max_file_size_mb: A[
int,
"Maximum size in MiB for one client-supplied remote media download. "
"The limit is enforced while streaming; set to 0 to disable it.",
NS("mm"),
] = 64
mm_preprocess_cache_size_mb: A[
Optional[int],
"CPU memory budget for content-addressed multimodal preprocessing "
"artifacts. Unset selects a model-specific default (256 MiB for "
"Kimi-K3); 0 disables the cache. The budget is divided across "
"tokenizer workers and does not reserve GPU memory.",
NS("mm"),
] = None
trust_mm_content_hashes: A[
bool,
"Trust caller-provided multimodal SHA-256 content hashes. This can "
"skip reading media on a hot metadata-cache hit; only enable it when "
"the caller guarantees that hashes identify immutable media bytes.",
NS("mm"),
] = False
limit_mm_data_per_request: A[
Optional[Union[str, Dict[str, int]]],
Arg(
help='Limit the number of multimodal inputs per request. e.g. \'{"image": 1, "video": 1, "audio": 1}\'',
type_parser=json.loads,
),
NS("mm"),
] = None
enable_mm_global_cache: A[
bool,
"Enable global multimodal embedding cache to skip redundant ViT inference.",
NS("mm"),
] = False
image_processor_backend: A[
Literal["auto", "torchvision", "pil"],
"Image processor backend. 'auto' lets Transformers select the best "
"available backend.",
NS("mm"),
] = "auto"
mm_global_cache_backend: A[
str,
Arg(
help="Storage backend for the multimodal global embedding cache. "
"Used when --enable-mm-global-cache is set.",
choices=["mooncake"],
),
NS("mm"),
] = "mooncake"
disable_fast_image_processor: A[
bool,
"Deprecated. Use --image-processor-backend=pil instead.",
NS("mm"),
] = False
mm_feature_transport: A[
Optional[Literal["cpu", "cuda_ipc", "cuda_vmm"]],
"Transport multimodal features through CPU memory, a bounded CUDA IPC "
"pool, or a bounded CUDA VMM pool. "
"Unset uses cpu except for validated multi-node GB200/GB300 MNNVL models, "
"which use cuda_vmm when an IMEX channel is available. Select cuda_ipc "
"explicitly for single-node GPU transport. GPU transports reserve "
"SGLANG_MM_FEATURE_CACHE_MB (default 1024 MiB) on the base GPU and fall "
"back to CPU transport when the pool is full.",
NS("mm"),
] = None
keep_mm_feature_on_device: A[
bool,
"Deprecated. Use --mm-feature-transport=cuda_ipc for bounded GPU-resident "
"multimodal feature transport.",
NS("mm"),
] = False
# -------------------------------------------------------------------------
# LoRA
# -------------------------------------------------------------------------
enable_lora: A[
Optional[bool],
"Enable LoRA support for the model. This argument is automatically set to True if `--lora-paths` is provided for backward compatibility.",
NS("lora"),
] = None
enable_lora_overlap_loading: A[
Optional[bool],
"Enable asynchronous LoRA weight loading in order to overlap H2D transfers with GPU compute. This should be enabled if you find that your LoRA workloads are bottlenecked by adapter weight loading, for example when frequently loading large LoRA adapters.",
NS("lora"),
] = None
max_lora_rank: A[
Optional[int],
"The maximum rank of LoRA adapters. If not specified, it will be automatically inferred from the adapters provided in --lora-paths.",
NS("lora"),
] = None
lora_target_modules: A[
Optional[Union[set[str], List[str]]],
Arg(
help="The union set of all target modules where LoRA should be applied. If not specified, it will be automatically inferred from the adapters provided in --lora-paths. If 'all' is specified, all supported modules will be targeted.",
nargs="*",
choices=SUPPORTED_LORA_TARGET_MODULES + [LORA_TARGET_ALL_MODULES],
),
NS("lora"),
] = None
lora_paths: A[
Optional[Union[dict[str, str], List[dict[str, str]], List[str], List[LoRARef]]],
Arg(
help='The list of LoRA adapters to load. Each adapter must be specified in one of the following formats: <PATH> | <NAME>=<PATH> | JSON with schema {"lora_name":str,"lora_path":str,"pinned":bool}',
action=LoRAPathAction,
action_kwargs={"type": str, "nargs": "*"},
),
NS("lora"),
] = None
max_loaded_loras: A[
Optional[int],
"If specified, it limits the maximum number of LoRA adapters loaded in CPU memory at a time. The value must be greater than or equal to `--max-loras-per-batch`.",
NS("lora"),
] = None
max_loras_per_batch: A[
int,
"Maximum number of adapters for a running batch, include base-only request.",
NS("lora"),
] = 8
lora_eviction_policy: A[
str,
Arg(
help="LoRA adapter eviction policy when memory pool is full. 'lru': Least Recently Used (default, better cache efficiency). 'fifo': First-In-First-Out.",
choices=["lru", "fifo"],
),
NS("lora"),
] = "lru"
lora_backend: A[
str,
Arg(
help="Choose the kernel backend for multi-LoRA serving.",
choices=["triton", "csgmv", "ascend", "torch_native"],
),
NS("lora"),
] = "csgmv"
max_lora_chunk_size: A[
Optional[int],
Arg(
help="Maximum chunk size for the ChunkedSGMV LoRA backend. Only used when --lora-backend is 'csgmv'. Choosing a larger value might improve performance.",
choices=[16, 32, 64, 128],
),
NS("lora"),
] = 16
experts_shared_outer_loras: A[
Optional[bool],
Arg(
help="Force shared outer LoRA mode for MoE models. When set, w1/w3 lora_A and w2 lora_B are shared across experts (expert_dim=1). Use --no-experts-shared-outer-loras to force disable. By default this is auto-detected from adapter weights.",
action=argparse.BooleanOptionalAction,
),
NS("lora"),
] = None
lora_use_virtual_experts: A[
bool,
"Enable virtual expert computation for MoE models. When set, the model will use virtual expert computation.",
NS("lora"),
] = False
lora_strict_loading: A[
bool,
Arg(
help="Enable strict loading for LoRA adapters. When set, mismatched or missing keys in the adapter weights will raise an error.",
action=argparse.BooleanOptionalAction,
),
NS("lora"),
] = False
lora_drain_wait_threshold: A[
float,
"When any LoRA adapter request waits longer than this threshold (in seconds), the scheduler will selectively drain one running adapter to make room. This mitigates extreme tail latency under high or skewed workloads by preventing a small set of adapters from monopolizing batch slots. Set to 0 to disable draining (default).",
NS("lora"),
] = 0.0
# -------------------------------------------------------------------------
# Two batch overlap
# -------------------------------------------------------------------------
enable_two_batch_overlap: A[
bool, "Enabling two micro batches to overlap.", NS("exec.overlap")
] = False
enable_single_batch_overlap: A[
bool,
"Let computation and communication overlap within one micro batch.",
NS("exec.overlap"),
] = False
tbo_token_distribution_threshold: A[
float,
"The threshold of token distribution between two batches in micro-batch-overlap, determines whether to two-batch-overlap or two-chunk-overlap. Set to 0 denote disable two-chunk-overlap.",
NS("exec.overlap"),
] = 0.48
# -------------------------------------------------------------------------
# Offloading
# -------------------------------------------------------------------------
cpu_offload_gb: A[
int, "How many GBs of RAM to reserve for CPU offloading.", NS("exec.offload")
] = 0
offload_group_size: A[
int, "Number of layers per group in offloading.", NS("exec.offload")
] = -1
offload_num_in_group: A[
int, "Number of layers to be offloaded within a group.", NS("exec.offload")
] = 1
offload_prefetch_step: A[
int, "Steps to prefetch in offloading.", NS("exec.offload")
] = 1
offload_mode: A[str, "Mode of offloading.", NS("exec.offload")] = "cpu"
# -------------------------------------------------------------------------
# LMCache
# -------------------------------------------------------------------------
enable_lmcache: A[
bool,
"Using LMCache as an alternative hierarchical cache solution",
NS("memory"),
] = False
lmcache_config_file: A[
Optional[str], "Path to the LMCache YAML configuration file", NS("memory")
] = None
# -------------------------------------------------------------------------
# FlexKV
# -------------------------------------------------------------------------
enable_flexkv: A[
bool,
(
"Route the default RadixCache through FlexKV's KVManager for "
"host-tier (CPU / SSD / Remote) KV cache offload. Equivalent "
"to --radix-cache-backend=flexkv but also participates in the "
"auto-selection chain alongside --enable-lmcache."
),
NS("memory"),
] = False
flexkv_config_file: A[
Optional[str],
(
"Path to the FlexKV YAML / JSON configuration file. "
"Equivalent to setting the FLEXKV_CONFIG_PATH environment "
"variable."
),
NS("memory"),
] = None
# -------------------------------------------------------------------------
# Ktransformers/AMX expert parallelism
# -------------------------------------------------------------------------
kt_weight_path: A[
Optional[str],
"[ktransformers parameter] The path of the quantized expert weights for amx kernel. A local folder.",
NS("exec.moe"),
] = None
kt_method: A[
str,
"[ktransformers parameter] Quantization formats for CPU execution.",
NS("exec.moe"),
] = "AMXINT4"
kt_cpuinfer: A[
Optional[int],
"[ktransformers parameter] The number of CPUInfer threads.",
NS("exec.moe"),
] = None
kt_threadpool_count: A[
int,
"[ktransformers parameter] One-to-one with the number of NUMA nodes (one thread pool per NUMA).",
NS("exec.moe"),
] = 2
kt_num_gpu_experts: A[
Optional[int],
"[ktransformers parameter] The number of GPU experts.",
NS("exec.moe"),
] = None
kt_max_deferred_experts_per_token: A[
Optional[int],
"[ktransformers parameter] Maximum number of experts deferred to CPU per token. All MoE layers except the final one use this value; the final layer always uses 0.",
NS("exec.moe"),
] = None
# -------------------------------------------------------------------------
# Diffusion LLM
# -------------------------------------------------------------------------
dllm_algorithm: A[
Optional[str],
"The diffusion LLM algorithm, such as LowConfidence.",
NS("exec.dllm"),
] = None
dllm_algorithm_config: A[
Optional[str],
"The diffusion LLM algorithm configurations. Must be a YAML file.",
NS("exec.dllm"),
] = None
dllm_fdfo: A[
bool,
Arg(
help="Enable First-Done-First-Out (FDFO) scheduling for diffusion LLM inference. Enabled by default; use --no-dllm-fdfo to fall back to synchronous block scheduling.",
action=argparse.BooleanOptionalAction,
),
NS("exec.dllm"),
] = True
# -------------------------------------------------------------------------
# PD disaggregation
# -------------------------------------------------------------------------
disaggregation_mode: A[
Literal["null", "prefill", "decode"],
'Only used for PD disaggregation. "prefill" for prefill-only server, and "decode" for decode-only server. If not specified, it is not PD disaggregated',
NS("disagg"),
] = "null"
disaggregation_transfer_backend: A[
str,
Arg(
help="The backend for disaggregation transfer. Default is mooncake.",
choices=DISAGG_TRANSFER_BACKEND_CHOICES,
),
NS("disagg"),
] = "mooncake"
disaggregation_bootstrap_port: A[
int,
"Bootstrap server port on the prefill server. Default is 8998.",
NS("disagg"),
] = 8998
disaggregation_ib_device: A[
Optional[str],
'The InfiniBand devices for disaggregation transfer. Supports a single device (e.g., --disaggregation-ib-device mlx5_0), a shared comma-separated list (e.g., --disaggregation-ib-device mlx5_0,mlx5_1), a per-GPU JSON mapping (e.g., --disaggregation-ib-device \'{"0": "mlx5_0,mlx5_1", "1": "mlx5_2"}\'), or a path to a JSON file containing that mapping. Default is None, which triggers automatic device detection when mooncake backend is enabled.',
NS("disagg"),
] = None
disaggregation_decode_enable_radix_cache: A[
bool,
"Enable radix cache on decode server (PD mode). Caches KV prefixes to avoid redundant transfers. Incompatible with --enable-hisparse, speculative decoding, and --disaggregation-transfer-backend fake.",
NS("disagg"),
] = False
disaggregation_decode_enable_offload_kvcache: A[
bool,
"Enable async KV cache offloading on decode server (PD mode).",
NS("disagg"),
] = False
disaggregation_decode_retraction_backup: A[
Optional[str],
Arg(
help=(
"Storage backend for KV preserved across PD decode retraction. "
"'cpu_tensor' uses per-request CPU tensors. 'host_pool' uses "
"a reserved HiCache pool and does not fall back on exhaustion. "
"If omitted, the backend is inferred from the decode KV pool."
),
choices=["cpu_tensor", "host_pool"],
),
NS("disagg"),
] = None
num_reserved_decode_tokens: A[
int,
"Number of decode tokens that will have memory reserved when adding new request to the running batch.",
NS("disagg"),
] = 512
disaggregation_decode_extra_slots: A[
Optional[int],
"Number of extra decode req_to_token slots pre-allocated for in-transfer requests (PD mode). If unset, defaults to 0 (or 2x the per-worker running batch for small batches).",
NS("disagg"),
] = None
disaggregation_decode_polling_interval: A[
int,
"The interval to poll requests in decode server. Can be set to >1 to reduce the overhead of this.",
NS("disagg"),
] = 1
optimistic_prefill_attempts: A[
int,
"Number of optimistic prefill forward passes that skip the bootstrap wait.",
NS("disagg"),
] = 0
# -------------------------------------------------------------------------
# Encode prefill disaggregation
# -------------------------------------------------------------------------
encoder_only: A[
bool, "For MLLM with an encoder, launch an encoder-only server", NS("disagg")
] = False
language_only: A[
bool, "For VLM, load weights for the language model only.", NS("disagg")
] = False
language_model_only: A[
bool,
"Skip the multimodal encoder entirely: its weights are never loaded and the "
"tower is never built, freeing that GPU memory for KV cache. Multimodal "
"requests are rejected. Unlike --language-only this is a standalone mode, "
"not part of encoder/decoder disaggregation.",
NS("disagg"),
] = False
encoder_transfer_backend: A[
str,
Arg(
help="The backend for encoder disaggregation transfer. Auto selects a model- and TP-aware backend.",
choices=["auto", "zmq_to_scheduler", "zmq_to_tokenizer", "mooncake"],
),
NS("disagg"),
] = "auto"
encoder_urls: A[List[str], "List of encoder server urls.", NS("disagg")] = (
dataclasses.field(default_factory=list)
)
encoder_bootstrap_port: A[
int,
"Port for the EncoderBootstrapServer that runs in the language-only tokenizer manager process. Encoders register here, and language-only receivers fetch the current URL list from here.",
NS("disagg"),
] = 8997
encoder_register_urls: A[
List[str],
"One or more EncoderBootstrapServer URLs to register this encoder with on startup, for dynamic encoder discovery. Example: --encoder-register-urls http://prefill0:8997 http://prefill1:8997. Used with --encoder-only servers.",
NS("disagg"),
] = dataclasses.field(default_factory=list)
enable_adaptive_dispatch_to_encoder: A[
bool,
"When enabled, adaptively dispatch: multi-image requests go to encoder in language_only epd mode, single-image requests are processed locally.",
NS("disagg"),
] = False
# -------------------------------------------------------------------------
# PD-Multiplexing
# -------------------------------------------------------------------------
enable_pdmux: A[
bool, "Enable PD-Multiplexing, PD running on greenctx stream.", NS("disagg")
] = False
pdmux_config_path: A[
Optional[str], "The path of the PD-Multiplexing config file.", NS("disagg")
] = None
sm_group_num: A[int, "Number of sm partition groups.", NS("disagg")] = 8
# -------------------------------------------------------------------------
# Model weight update and weight loading
# -------------------------------------------------------------------------
startup_weight_load_mode: A[
Literal["serial", "overlap"],
(
"Control startup weight loading relative to CUDA graph capture. "
"'serial' preserves the existing startup order; 'overlap' stages "
"checkpoint files while CUDA graphs are captured and commits the "
"real weights afterward."
),
NS("model"),
] = "serial"
custom_weight_loader: A[
Optional[List[str]],
Arg(
help="The custom dataloader which used to update the model. Should be set with a valid import path, such as my_package.weight_load_func",
nargs="*",
),
NS("model"),
] = None
weight_loader_disable_mmap: A[
bool, "Disable mmap while loading weight using safetensors.", NS("model")
] = False
weight_loader_prefetch_checkpoints: A[
bool,
"Prefetch checkpoint files into OS page cache before loading. Each rank prefetches a fraction of the shards, reducing total network I/O on shared filesystems (NFS/Lustre) from N*checkpoint to 1*checkpoint. Recommended for models on network storage. When enabled, multi-threaded safetensors loading is disabled by default to avoid I/O oversubscription with the prefetch threads; set enable_multithread_load=true in --model-loader-extra-config to keep multi-threaded loading (e.g. on local NVMe where prefetch is a no-op).",
NS("model"),
] = False
weight_loader_prefetch_num_threads: A[
int,
"Number of threads per rank for checkpoint prefetching (default: 4).",
NS("model"),
] = 4
weight_loader_drop_cache_after_load: A[
bool,
"Call posix_fadvise(DONTNEED) on each safetensors shard after loading it.",
NS("model"),
] = False
remote_instance_weight_loader_seed_instance_ip: A[
Optional[str],
"The ip of the seed instance for loading weights from remote instance.",
NS("model"),
] = None
remote_instance_weight_loader_seed_instance_service_port: A[
Optional[int],
"The service port of the seed instance for loading weights from remote instance.",
NS("model"),
] = None
remote_instance_weight_loader_send_weights_group_ports: A[
Optional[List[int]],
Arg(
help="The communication group ports for loading weights from remote instance.",
type_parser=json_list_type,
),
NS("model"),
] = None
remote_instance_weight_loader_backend: A[
Literal["transfer_engine", "nccl", "modelexpress"],
"The backend for loading weights from remote instance. Can be 'transfer_engine', 'nccl', or 'modelexpress'. Default is 'nccl'.",
NS("model"),
] = "nccl"
remote_instance_weight_loader_start_seed_via_transfer_engine: A[
bool,
"Start seed server via transfer engine backend for remote instance weight loader.",
NS("model"),
] = False
engine_info_bootstrap_port: A[
int,
"Port for the engine info bootstrap server. Default is 6789. Must be set explicitly when running multiple instances on the same node.",
NS("model"),
] = 6789
modelexpress_config: A[
Optional[str],
'JSON config for ModelExpress P2P weight loading. Keys: "url" (optional gRPC host:port override), "transport" ("nixl" or "transfer_engine"). Example: \'{"url": "localhost:8001", "transport": "nixl"}\'',
NS("model"),
] = None
download_dir: A[
Optional[str], "Model download directory for huggingface.", NS("model")
] = None
model_checksum: A[
Optional[str],
Arg(
help="Model file integrity verification. If provided without value, uses model-path as HF repo ID. Otherwise, provide checksums JSON file path or HuggingFace repo ID.",
nargs="?",
const="",
),
NS("model"),
] = None
delete_ckpt_after_loading: A[
bool, "Delete the model checkpoint after loading the model.", NS("model")
] = False
# Checkpoint decryption
decrypted_config_file: A[
Optional[str], "The path of the decrypted config file.", NS("model")
] = None
decrypted_draft_config_file: A[
Optional[str], "The path of the decrypted draft config file.", NS("model")
] = None
checkpoint_engine_wait_weights_before_ready: A[
bool,
"If set, the server will wait for initial weights to be loaded via checkpoint-engine or other update methods before serving inference requests.",
NS("model"),
] = False
# -------------------------------------------------------------------------
# Prefill delayer
# -------------------------------------------------------------------------
enable_prefill_delayer: A[
bool,
"Enable prefill delayer for DP attention to reduce idle time.",
NS("schedule"),
] = False
prefill_delayer_max_delay_passes: A[
int, "Maximum forward passes to delay prefill.", NS("schedule")
] = 30
prefill_delayer_token_usage_low_watermark: A[
Optional[float],
"Token usage low watermark for prefill delayer.",
NS("schedule"),
] = None
prefill_delayer_forward_passes_buckets: A[
Optional[List[float]],
"Custom buckets for prefill delayer forward passes histogram. 0 and max_delay_passes-1 will be auto-added.",
NS("schedule"),
] = None
prefill_delayer_wait_seconds_buckets: A[
Optional[List[float]],
"Custom buckets for prefill delayer wait seconds histogram. 0 will be auto-added.",
NS("schedule"),
] = None
prefill_delayer_queue_min_ratio: A[
Optional[float],
(
"Opt-in to the adaptive queue-based delay trigger (independent of the "
"slot-based one). Delays prefill until the waiting queue reaches "
"min(running_req * ratio, prefill_max_requests), falling back to the "
"observed max_prefill_bs when no request limit is set. Unset (default) "
"keeps the original slot-only behavior. Typical: 0.1 ~ 0.5."
),
NS("schedule"),
] = None
prefill_delayer_max_delay_ms: A[
Optional[float],
(
"Wall-clock cap (ms) on a single queue-trigger delay; once exceeded, "
"prefill is force-released to bound worst-case TTFT. Only consulted "
"when --prefill-delayer-queue-min-ratio is set. Typical: 1000 ~ "
"5000; defaults to 5000 if unset."
),
NS("schedule"),
] = None
# -------------------------------------------------------------------------
# Min free slots delay (prefill refill batching)
# -------------------------------------------------------------------------
min_free_slots_delay: A[
Optional[int],
(
"Hold new prefills until at least N running-request slots have freed "
"up, so they are admitted in one batch instead of one at a time. "
"Useful when each admission is disproportionately expensive, e.g. "
"speculative decoding with a separate draft prefill pass. An "
"explicit value always wins, capped by max-running-requests "
"(1 disables). When unset, DFlash workloads auto-enable the "
"formula; other workloads stay disabled. Not supported with "
"pipeline parallelism."
),
NS("schedule"),
] = None
# -------------------------------------------------------------------------
# Deterministic inference
# -------------------------------------------------------------------------
enable_deterministic_inference: A[
bool,
"Enable deterministic inference mode with batch invariant ops.",
NS("exec.deterministic"),
] = False
rl_on_policy_target: A[
Optional[str],
Arg(
help="The training system that SGLang needs to match for true on-policy.",
choices=RL_ON_POLICY_TARGET_CHOICES,
),
NS("exec.deterministic"),
] = None
# -------------------------------------------------------------------------
# KV canary
# -------------------------------------------------------------------------
kv_canary: A[
str,
Arg(
help="KV cache canary mode. 'none' disables the canary (default). 'log' prints them while the server keeps running (production-safe). 'raise' fails the server on the first detected mismatch (CI lane).",
choices=["none", "log", "raise"],
),
NS("observability"),
] = "none"
kv_canary_real_data: A[str, NS("observability")] = "none"
kv_canary_sweep_interval: A[
int, "Every N forward steps, run a full-pool sweep.", NS("observability")
] = 0
# -------------------------------------------------------------------------
# Dynamic batch tokenizer
# -------------------------------------------------------------------------
enable_dynamic_batch_tokenizer: A[
bool,
"Enable async dynamic batch tokenizer for improved performance when multiple requests arrive concurrently.",
NS("serving"),
] = False
dynamic_batch_tokenizer_batch_size: A[
int,
"[Only used if --enable-dynamic-batch-tokenizer is set] Maximum batch size for dynamic batch tokenizer.",
NS("serving"),
] = 32
dynamic_batch_tokenizer_batch_timeout: A[
float,
"[Only used if --enable-dynamic-batch-tokenizer is set] Timeout in seconds for batching tokenization requests.",
NS("serving"),
] = 0.002
enable_tokenizer_batch_encode: A[
bool,
"Enable batch tokenization for improved performance when processing multiple text inputs. Do not use with image inputs, pre-tokenized input_ids, or input_embeds.",
NS("serving"),
] = False
disable_tokenizer_batch_decode: A[
bool,
"Disable batch decoding when decoding multiple completions.",
NS("serving"),
] = False
# -------------------------------------------------------------------------
# Debug tensor dumps
# -------------------------------------------------------------------------
debug_tensor_dump_output_folder: A[
Optional[str],
"The output folder for dumping tensors. In Eagle mode, tensor outputs from draft and target models are stored in separate subdirectories ('draft' and 'target').",
NS("observability"),
] = None
# None means dump all layers.
debug_tensor_dump_layers: A[
Optional[List[int]],
"The layer ids to dump. Dump all layers if not specified.",
NS("observability"),
] = None
# TODO(guoyuhong): clean the old dumper code.
debug_tensor_dump_input_file: A[
Optional[str], "The input filename for dumping tensors", NS("observability")
] = None
# -------------------------------------------------------------------------
# Misc runtime features
# -------------------------------------------------------------------------
enable_memory_saver: A[
bool,
"Allow saving memory using release_memory_occupation and resume_memory_occupation",
NS("exec.features"),
] = False
enable_weights_cpu_backup: A[
bool,
"Save model weights (both main model and draft model, if any) to CPU memory during release_weights_occupation and resume_weights_occupation",
NS("exec.features"),
] = False
enable_draft_weights_cpu_backup: A[
bool,
"Save draft model weights to CPU memory during release_weights_occupation and resume_weights_occupation",
NS("exec.features"),
] = False
enable_custom_logit_processor: A[
bool,
"Enable users to pass custom logit processors to the server (disabled by default for security)",
NS("exec.features"),
] = False
enable_return_hidden_states: A[
bool,
"Enable returning full hidden states with responses. Equivalent to "
"`--return-hidden-states-mode full`.",
NS("exec.features"),
] = False
return_hidden_states_mode: A[
Optional[str],
Arg(
help="Set the maximum hidden-state return mode supported by the "
"server. `last` allows requests with return_hidden_states=False or "
"`last`; `full` also allows return_hidden_states=True.",
choices=["last", "full"],
),
NS("exec.features"),
] = None
enable_return_routed_experts: A[
bool,
"Enable returning routed experts of each layer with responses.",
NS("exec.features"),
] = False
enable_return_indexer_topk: A[
bool,
"Enable returning indexer topk indices of layers with indexer with responses.",
NS("exec.features"),
] = False
disable_outlines_disk_cache: A[
bool,
"Disable disk cache of outlines to avoid possible crashes related to file system or high concurrency.",
NS("exec.features"),
] = False
enable_mis: A[
bool,
"Enable Multi-Item Scoring optimization. Combines query and multiple items into a single sequence for efficient batch processing. Requires --attention-backend flashinfer; auto-disables CUDA graph, radix cache, and chunked prefill.",
NS("exec.features"),
] = False
# -------------------------------------------------------------------------
# Weight cache
# -------------------------------------------------------------------------
weight_cache_mode: A[
str,
Arg(
help="Weight cache mode. 'off': normal disk loading. "
"'daemon': launch weight cache daemon (holds weights in GPU memory). "
"Engine-spawned daemons are co-terminal with the engine and do NOT "
"persist across restarts, so this alone does not speed up restart "
"(the first start is slower). For fast recovery, run the standalone "
"daemon (python -m sglang.srt.weight_cache.daemon) and connect with "
"'client'. 'client': connect to existing daemon and load via IPC.",
choices=["off", "daemon", "client"],
),
NS("model"),
] = "off"
weight_cache_socket: A[
Optional[str],
Arg(
help="Unix socket path for weight cache daemon (client mode)."
"If not set, derives the path from SGLANG_WEIGHT_CACHE_SOCKET_TEMPLATE "
"using the caller's physical GPU UUID.",
),
NS("model"),
] = None
weight_cache_timeout: A[
int,
Arg(
help="Timeout in seconds for weight cache daemon readiness (default: 1800).",
),
NS("model"),
] = 1800
# -------------------------------------------------------------------------
# Custom hooks, probe, and plugins
# -------------------------------------------------------------------------
forward_hooks: A[
Optional[List[dict[str, Any]]],
Arg(
help="JSON-formatted forward hook specifications to attach to the model.",
type_parser=json_list_type,
),
NS("observability"),
] = None
msprobe_dump_config: A[
Optional[str],
"The path of the JSON configuration file for msProbe. If specified, enables msProbe dump.",
NS("observability"),
] = None
def __post_init__(self):
"""Construction leaves the record at what the caller asked for.
Resolution is a separate act, entered through ``resolve_once``: the
launcher runs it once per engine, and every publishing process asks the
gate on the way in. A record that is only constructed -- a fixture, a
config being inspected, one being handed to a subprocess that will
resolve it itself -- stays raw.
"""
def resolve_once(self) -> None:
"""Run the resolution pipeline, unless this record has been through it.
Resolution is a deterministic function of the raw inputs -- two records
built from the same arguments declare the same things -- but the
handlers do not survive a second pass over their own output: DP
attention halves ``chunked_prefill_size`` again on every re-entry.
The publishing entry of every process calls this. In a child the record
arrived by pickle and brought its declarations along, so the child has
nothing left to derive and projects what the parent decided.
"""
if getattr(self, "_resolution_finished", False):
return
if getattr(self, "_resolution_failed", False):
raise RuntimeError(
"resolution already failed on this ServerArgs; the handlers that "
"ran left their writes on the record, and a second pass would "
"read that partial output as fresh input. Build a new record "
"from the corrected arguments."
)
from sglang.srt.arg_groups.pipeline import run_resolution_pipeline
try:
run_resolution_pipeline(self)
except BaseException:
# The handlers that ran already declared, and they are not
# idempotent over their own output.
self._resolution_failed = True
raise
# Set here too, because the dummy/absent-model path returns before the
# end of the pipeline that normally sets it: the gate is about whether
# the handlers ran, not how far they got.
self._resolution_finished = True
def resolved_dict(self) -> Dict[str, Any]:
"""This configuration as a plain dict of resolved field values.
What the whole-object readbacks report (`/server_info` and its gRPC and
in-process twins). `dataclasses.asdict(self)` reads the fields, which
carry the raw input; this reads the declarations, so it answers with what
resolution decided. Nested dataclass fields are expanded
the way `asdict` expands them; the private resolution bookkeeping and the
`model_config` memo are not fields and do not appear.
"""
return resolution_projection(self)
def replace_resolved(self, source: str, **changes: Any) -> ServerArgs:
"""A copy of this record that stays resolved, and says what it changed.
`dataclasses.replace` builds a new instance, so the copy carries none of
what makes a record resolved: no raw snapshot, no declarations, no
finished flag. The next publish therefore resolves it again, which
drops every decision the stash held -- the late ones (the auto-detected
parsers) and the direct ones alike -- and re-runs the device probes in
whatever process opened the copy. The Ray paths replace
`dist_init_addr` on a resolved record, which is how they reach this.
The change is appended to the stash rather than left on the field: the
projection reads the raw snapshot plus the declarations, so a field the
copy set on its own would publish the parent's raw value instead.
The carry is shallow. The containers are copied so the copy's own
declaration does not travel back into the parent, but everything inside
them -- the stash entries, the raw-input values, the memoized
`ModelConfig` -- is shared. That is fine for what this is for: a copy
that immediately crosses a process boundary (Ray actors, the gateway's
workers), where pickling severs the sharing. A caller that mutates the
copy's deep structure in-process mutates the parent's too.
"""
replacement = dataclasses.replace(self, **changes)
if not getattr(self, "_resolution_finished", False):
# Not resolved yet: the copy goes through the gate itself.
return replacement
# Everything outside the fields, enumerated from the instance: the raw
# snapshot, the stash, and what resolution memoized -- including the
# model-configuration memo, which the copy carries over rather than
# rebuild.
field_names = {field.name for field in dataclasses.fields(self)}
for name, value in vars(self).items():
if name in field_names or name == "_resolution_finished":
continue
if isinstance(value, (dict, list, set)):
value = copy.copy(value)
object.__setattr__(replacement, name, value)
stash = getattr(replacement, "_resolved_overrides", None)
if stash is None:
stash = []
object.__setattr__(replacement, "_resolved_overrides", stash)
if changes:
stash.append((source, dict(changes)))
object.__setattr__(replacement, "_resolution_finished", True)
return replacement
# ------------------------------------------------------------------
# CUDA graph configuration resolution
# ------------------------------------------------------------------
# ===== END TO BE REFACTORED ====
LANGUAGE_MODEL_ONLY_ARCHITECTURES = (
"MuseGlimmerForConditionalGeneration",
"Cosmos3ForConditionalGeneration",
"Cosmos3EdgeForConditionalGeneration",
)
# The attention-backend allow-list is enforced via
# --enable-page-major-kv-layout (implied by the unified pool in
# _handle_page_major_kv_layout); the model-family gate is enforced at pool
# construction in model_runner_kv_cache_mixin._init_pools.
@staticmethod
def add_cli_args(parser: argparse.ArgumentParser):
# Auto-derived from Annotated[..., Arg(...)] field metadata.
add_cli_args_from_dataclass(parser, ServerArgs)
# --- Fields with dynamic choices (computed at add_cli_args time) ---
sampling_backend_choices = set(SAMPLING_BACKEND_CHOICES)
if envs.SGLANG_KV_CANARY_ENABLE_TOKEN_ORACLE.get():
sampling_backend_choices.add("token_oracle")
parser.add_argument(
"--sampling-backend",
type=str,
choices=sampling_backend_choices,
default=ServerArgs.sampling_backend,
help="Choose the kernels for sampling layers.",
)
reasoning_parser_choices = list(ReasoningParser.DetectorMap.keys())
parser.add_argument(
"--reasoning-parser",
type=str,
choices=["auto"] + reasoning_parser_choices,
default=ServerArgs.reasoning_parser,
help=f"Specify the parser for reasoning models. "
f"Use 'auto' to detect from chat template. "
f"Options include: {reasoning_parser_choices}.",
)
tool_call_parser_choices = list(FunctionCallParser.ToolCallParserEnum.keys())
parser.add_argument(
"--tool-call-parser",
type=str,
choices=["auto"] + tool_call_parser_choices,
default=ServerArgs.tool_call_parser,
help=f"Specify the parser for handling tool-call interactions. "
f"Use 'auto' to detect from chat template. "
f"Options include: {tool_call_parser_choices}.",
)
parser.add_argument(
"--kv-canary-real-data",
type=str,
default=ServerArgs.kv_canary_real_data,
choices=[m.name.lower() for m in RealKvHashMode],
help=(
"Check the real KV-cache in the canary. "
"'none' (default) disables the feature. "
"'partial' checks the first 16 bytes of each real-KV slot. "
"'all' checks the full real-KV slot."
),
)
# --- Configuration file support ---
parser.add_argument(
"--config",
type=str,
help="Read CLI options from a config file. Must be a YAML file with configuration options.",
)
# --- Deprecated argument registrations ---
parser.add_argument(
"--enable-expert-distribution-metrics",
action=DeprecatedAction,
error_message=(
"--enable-expert-distribution-metrics is no longer supported. Use "
"--expert-balancedness-report-mode with one of: off, server_log, "
"prometheus, both."
),
help=(
"Removed. Use --expert-balancedness-report-mode with one of: "
"off, server_log, prometheus, both."
),
)
parser.add_argument(
"--stream-output",
action=DeprecatedStoreTrueAction,
dest="incremental_streaming_output",
new_flag="--incremental-streaming-output",
help="[Deprecated] Use --incremental-streaming-output instead.",
)
parser.add_argument(
"--prefill-round-robin-balance",
action=DeprecatedAction,
help="Note: --prefill-round-robin-balance is deprecated now.",
)
parser.add_argument(
"--collect-tokens-histogram",
action=DeprecatedAction,
help="Deprecated. Token histograms are now automatically collected when --enable-metrics is set.",
)
parser.add_argument(
"--nsa-prefill-backend",
dest="dsa_prefill_backend",
action=DeprecatedAliasStoreAction,
new_flag="--dsa-prefill-backend",
default=argparse.SUPPRESS,
type=str,
choices=[
"flashmla_sparse",
"flashmla_sparse_q8",
"flashmla_kv",
"flashmla_auto",
"flashinfer_sparse_mla",
"fa3",
"tilelang",
"aiter",
"trtllm",
],
help="[Deprecated] Use --dsa-prefill-backend instead.",
)
parser.add_argument(
"--nsa-decode-backend",
dest="dsa_decode_backend",
action=DeprecatedAliasStoreAction,
new_flag="--dsa-decode-backend",
default=argparse.SUPPRESS,
type=str,
choices=[
"flashmla_sparse",
"flashmla_sparse_q8",
"flashmla_kv",
"flashmla_auto",
"flashinfer_sparse_mla",
"fa3",
"tilelang",
"aiter",
"trtllm",
],
help="[Deprecated] Use --dsa-decode-backend instead.",
)
parser.add_argument(
"--speculative-dflash-draft-window-size",
type=int,
dest="speculative_draft_window_size",
action=DeprecatedAliasStoreAction,
new_flag="--speculative-draft-window-size",
help=argparse.SUPPRESS,
)
parser.add_argument(
"--mamba-scheduler-strategy",
dest="mamba_radix_cache_strategy",
type=str,
action=DeprecatedAliasStoreAction,
new_flag="--mamba-radix-cache-strategy",
default=ServerArgs.mamba_radix_cache_strategy,
help="Deprecated alias for --mamba-radix-cache-strategy.",
)
parser.add_argument(
"--cuda-graph-max-bs",
type=int,
action=DeprecatedAliasStoreAction,
new_flag="--cuda-graph-max-bs-decode",
dest="cuda_graph_max_bs_decode",
help="Deprecated alias for --cuda-graph-max-bs-decode.",
)
parser.add_argument(
"--cuda-graph-bs",
type=int,
nargs="+",
action=DeprecatedAliasStoreAction,
new_flag="--cuda-graph-bs-decode",
dest="cuda_graph_bs_decode",
help="Deprecated alias for --cuda-graph-bs-decode.",
)
parser.add_argument(
"--disable-cuda-graph",
action=DeprecatedStoreTrueAction,
new_flag="--cuda-graph-backend-{decode,prefill}=disabled",
help="Deprecated. Use --cuda-graph-backend-{decode,prefill}=disabled instead.",
)
parser.add_argument(
"--enable-breakable-cuda-graph",
action=DeprecatedStoreConstAction,
dest="cuda_graph_backend_prefill",
const_value=Backend.BREAKABLE,
new_flag="--cuda-graph-backend-prefill=breakable",
help="Deprecated alias for --cuda-graph-backend-prefill=breakable.",
)
parser.add_argument(
"--disable-piecewise-cuda-graph",
action=DeprecatedStoreConstAction,
dest="cuda_graph_backend_prefill",
const_value=Backend.DISABLED,
new_flag="--cuda-graph-backend-prefill=disabled",
help="Deprecated alias for --cuda-graph-backend-prefill=disabled.",
)
parser.add_argument(
"--enforce-piecewise-cuda-graph",
action=DeprecatedStoreConstAction,
dest="cuda_graph_backend_prefill",
const_value=Backend.TC_PIECEWISE,
new_flag="--cuda-graph-backend-prefill=tc_piecewise",
help="Deprecated alias for --cuda-graph-backend-prefill=tc_piecewise. "
"Explicitly setting the prefill backend now skips the auto-disable "
"cascade automatically.",
)
parser.add_argument(
"--piecewise-cuda-graph-tokens",
type=int,
nargs="+",
action=DeprecatedAliasStoreAction,
new_flag="--cuda-graph-bs-prefill",
dest="cuda_graph_bs_prefill",
help="Deprecated alias for --cuda-graph-bs-prefill.",
)
parser.add_argument(
"--piecewise-cuda-graph-compiler",
type=str,
choices=["eager", "inductor"],
action=DeprecatedAliasStoreAction,
new_flag="--cuda-graph-tc-compiler",
dest="cuda_graph_tc_compiler",
help="Deprecated alias for --cuda-graph-tc-compiler.",
)
parser.add_argument(
"--piecewise-cuda-graph-max-tokens",
type=int,
action=DeprecatedAliasStoreAction,
new_flag="--cuda-graph-max-bs-prefill",
dest="cuda_graph_max_bs_prefill",
help="Deprecated alias for --cuda-graph-max-bs-prefill.",
)
parser.add_argument(
"--enable-nsa-prefill-context-parallel",
dest="enable_dsa_prefill_context_parallel",
action=DeprecatedStoreTrueAction,
new_flag="--enable-prefill-cp",
help="[Deprecated] Use --enable-prefill-cp instead.",
)
parser.add_argument(
"--enable-gdn-replayssm-spec",
dest="enable_linear_replayssm_spec",
action=DeprecatedStoreTrueAction,
new_flag="--enable-linear-replayssm-spec",
help="[Deprecated] Use --enable-linear-replayssm-spec instead.",
)
parser.add_argument(
"--enable-prefill-context-parallel",
dest="enable_prefill_context_parallel",
action=DeprecatedStoreTrueAction,
new_flag="--enable-prefill-cp",
help="[Deprecated] Use --enable-prefill-cp instead.",
)
parser.add_argument(
"--nsa-prefill-cp-mode",
dest="dsa_prefill_cp_mode",
action=DeprecatedAliasStoreAction,
new_flag="--cp-strategy",
type=str,
default=argparse.SUPPRESS,
choices=["in-seq-split", "round-robin-split"],
help="[Deprecated] Use --cp-strategy instead.",
)
parser.add_argument(
"--enable-flashinfer-allreduce-fusion",
action="store_true",
help="(Deprecated: use --flashinfer-allreduce-fusion-backend=auto) "
"Enable FlashInfer allreduce fusion with Residual RMSNorm.",
)
@classmethod
def from_cli_args(cls, args: argparse.Namespace):
# Some dataclass fields (e.g. stat_loggers) intentionally have no CLI
# surface and won't appear on the argparse Namespace. Skip them so the
# dataclass default applies.
attrs = [
attr.name for attr in dataclasses.fields(cls) if hasattr(args, attr.name)
]
return cls(**{attr: getattr(args, attr) for attr in attrs})
def get_tokenizer_worker_class(self):
from sglang.srt.managers.multi_tokenizer_mixin import TokenizerWorker
return TokenizerWorker
def url(self, port: Optional[int] = None):
scheme = "https" if self.ssl_certfile else "http"
# When binding to all interfaces, use loopback for internal requests.
host = self.host
if not host or host == "0.0.0.0":
host = "127.0.0.1"
elif host == "::":
host = "::1"
return NetworkAddress(host, port if port is not None else self.port).to_url(
scheme
)
@property
def engine_info_bootstrap_url(self):
return self.url(port=self.engine_info_bootstrap_port)
@property
def is_ep_joiner(self) -> bool:
"""True for processes launched as elastic-EP joiners."""
cfg = resolving_view(self)
return cfg.ep_join_mode in ("scale", "recover")
@property
def is_ep_scale_joiner(self) -> bool:
cfg = resolving_view(self)
return cfg.ep_join_mode == "scale"
@property
def is_startup_weight_load_overlap(self) -> bool:
cfg = resolving_view(self)
return cfg.startup_weight_load_mode == "overlap"
def __setattr__(self, name, value):
# Once resolution has finished the record is the READ-ONLY raw input
# the config bags were projected from. Resolved config changes go to the bags via
# get_context().override(source, ...); a value one runner or worker
# owns travels as a constructor argument to it.
if getattr(self, "_resolution_finished", False) and (
not name.startswith("_") or name in _underscore_field_names()
):
raise AttributeError(
f"server_args.{name} assigned after resolution; server_args is "
"read-only -- use get_context().override(source, ...) to change "
"resolved config; a value one runner owns travels as a "
"constructor argument."
)
object.__setattr__(self, name, value)
def enable_mamba_extra_buffer(self) -> bool:
return mamba_extra_buffer_of(resolving_view(self))
def enable_mamba_extra_buffer_lazy(self) -> bool:
return mamba_extra_buffer_lazy_of(resolving_view(self))
def check_server_args(self):
from sglang.srt.arg_groups.validation_hook import check_server_args
check_server_args(self)
def remote_instance_weight_loader_use_transfer_engine(self, load_format=None):
"""``load_format`` overrides the seed's: a draft runner loading under
``--speculative-draft-load-format`` needs its own transfer engine."""
return remote_instance_transfer_engine_of(resolving_view(self), load_format)
# --------------------------------------------------------------------------
# Module-level ServerArgs helpers and runtime shims.
# --------------------------------------------------------------------------
def resolve_encoder_transfer_backend(
backend: str, model_arch: str, tp_size: int
) -> str:
if backend != "auto":
return backend
if model_arch == "KimiK3ForConditionalGeneration" and tp_size > 1:
return "zmq_to_tokenizer"
return "zmq_to_scheduler"
def compute_world_size(
*, enable_dp_attention: bool, dp_size: int, tp_size: int, pp_size: int
) -> int:
"""Total GPU count across all data-parallel replicas.
Takes the values rather than a config object: the two sizes are the widths
the launch asked for, which the Ray driver needs before any process group
exists, and passing a context would hand it the live groups instead.
"""
return (1 if enable_dp_attention else dp_size) * tp_size * pp_size
def m3_fp8_attn_gemm_enabled(args) -> bool:
"""Whether MiniMax-M3 attention GEMMs run in fp8 (no opt-in flag; active
whenever possible): fp8_e4m3 main + index KV caches, fp8-cast q, fp8
sparse/MSA kernels, with dense layers on trtllm_mha's fp8-q path. Needs
kv_cache_dtype fp8_e4m3 (e5m2 would silently mis-dispatch fmha_sm100's
e4m3 kernel), the trtllm_mha backend (the only dense backend with fp8-q
GEMMs), and SM100 (MSA fp8 variants and trtllm-gen fp8 dense kernels are
sm100-only). SGLANG_DISABLE_M3_FP8_ATTN_GEMM=1 is the kill switch:
it forces the pre-fp8 numerics (bf16 indexer + widening sparse path,
bf16 q) without having to move off trtllm_mha.
"""
from sglang.srt.environ import envs
return (
args.kv_cache_dtype == "fp8_e4m3"
and args.attention_backend == "trtllm_mha"
and get_platform().is_sm100
and not envs.SGLANG_DISABLE_M3_FP8_ATTN_GEMM.get()
)
# NOTE: The process-wide ServerArgs is owned by the runtime context
# (sglang.srt.runtime_context). The two functions below are LEGACY shims kept
# for the existing call-sites; they publish/read the same live object by
# reference. Do not add new call-sites — the counts are ratcheted
# (decrease-only) by test/registered/unit/test_legacy_global_ratchet.py.
# Imports are in-function so the two modules stay cycle-free at import time.
@functools.lru_cache(maxsize=1)
def _underscore_field_names() -> frozenset:
"""Real dataclass fields whose names start with an underscore.
The read-only guard exempts underscore names because they are the record's
own bookkeeping (the stash, the flags, the cache keys). A *field* that
happens to start with an underscore is still resolved configuration --
`_speculative_draft_quantization_explicitly_set` is one -- and exempting it
by spelling would leave exactly one leaf writable on a read-only record.
"""
return frozenset(
field.name
for field in dataclasses.fields(ServerArgs)
if field.name.startswith("_")
)
def set_global_server_args_for_scheduler(server_args: ServerArgs):
"""Legacy publish shim (role=scheduler) — prefer
``runtime_context.publish(server_args, role=...)`` in new code."""
publish(server_args, role="scheduler")
def set_global_server_args_for_tokenizer(server_args: ServerArgs):
"""Legacy publish shim (role=tokenizer). Not aliased to the scheduler shim:
the process role differs."""
publish(server_args, role="tokenizer")
def get_global_server_args() -> ServerArgs:
"""Legacy accessor shim — prefer ``get_server_args()`` from
``sglang.srt.runtime_context`` in new code."""
return get_context().server_args
def prepare_server_args(argv: List[str]) -> ServerArgs:
"""
Prepare the server arguments from the command line arguments.
Args:
args: The command line arguments. Typically, it should be `sys.argv[1:]`
to ensure compatibility with `parse_args` when no arguments are passed.
Returns:
The server arguments.
"""
parser = argparse.ArgumentParser(prog="sglang serve")
ServerArgs.add_cli_args(parser)
# Check for config file and merge arguments if present
if "--config" in argv:
# Import here to avoid circular imports
from sglang.srt.utils.server_args_config_parser import ConfigArgumentMerger
# Extract boolean actions from the parser to handle them correctly
config_merger = ConfigArgumentMerger(parser)
argv = config_merger.merge_config_with_args(argv)
raw_args = parser.parse_args(argv)
# Set up basic logging before ServerArgs.__post_init__ so that
# logger.info / logger.warning calls there are properly formatted.
logging.basicConfig(
level=getattr(logging, raw_args.log_level.upper()),
format="[%(asctime)s] %(message)s",
datefmt="%Y-%m-%d %H:%M:%S",
force=True,
)
return ServerArgs.from_cli_args(raw_args)
# --------------------------------------------------------------------------
# Networking constants and PortArgs.
# --------------------------------------------------------------------------
ZMQ_TCP_PORT_DELTA = 233
DP_ATTENTION_HANDSHAKE_PORT_DELTA = 13
@dataclasses.dataclass
class PortArgs:
# The ipc filename for tokenizer to receive inputs from detokenizer (zmq)
tokenizer_ipc_name: str
# The ipc filename for scheduler (rank 0) to receive inputs from tokenizer (zmq)
scheduler_input_ipc_name: str
# The ipc filename for detokenizer to receive inputs from scheduler (zmq)
detokenizer_ipc_name: str
# The port for nccl initialization (torch.dist)
nccl_port: int
# The ipc filename for rpc call between Engine and Scheduler
rpc_ipc_name: str
# The ipc filename for Scheduler to send metrics
metrics_ipc_name: str
# The ipc filename for MultiTokenizerRouter to receive inputs from TokenizerWorker processes (zmq)
tokenizer_worker_ipc_name: Optional[str]
# The ipc endpoints between verifier scheduler and drafter scheduler
decoupled_spec_ipc_config: Optional[DecoupledSpecIpcConfig]
# zmq address for load snapshot PUSH/PULL (dp-attention TCP mode only;
# empty when IPC mode derives the address from instance_id).
load_collector_ipc_name: str = ""
# Stable token shared by all processes in one server instance, used to
# derive the /dev/shm path for load snapshots.
instance_id: str = ""
@staticmethod
def init_new(
server_args: ServerArgs,
dp_rank: Optional[int] = None,
worker_ports: Optional[List[int]] = None,
) -> PortArgs:
cfg = resolving_view(server_args)
if server_args.nccl_port is None:
nccl_port = get_free_port()
else:
nccl_port = server_args.nccl_port
if server_args.tokenizer_worker_num == 1:
tokenizer_worker_ipc_name = None
else:
tokenizer_worker_ipc_name = (
f"ipc://{tempfile.NamedTemporaryFile(delete=False).name}"
)
instance_id = uuid.uuid4().hex[:12]
decoupled_spec_ipc_config = None
if server_args.decoupled_spec_role != "null":
if (
server_args.decoupled_spec_bind_endpoint is None
or server_args.decoupled_spec_connect_endpoints is None
or server_args.decoupled_spec_rank is None
):
raise ValueError(
"--decoupled-spec-bind-endpoint, "
"--decoupled-spec-connect-endpoints, and "
"--decoupled-spec-rank are required for decoupled speculative decoding."
)
decoupled_spec_ipc_config = DecoupledSpecIpcConfig(
bind_endpoint=server_args.decoupled_spec_bind_endpoint,
connect_endpoints=tuple(server_args.decoupled_spec_connect_endpoints),
rank=int(server_args.decoupled_spec_rank),
)
if not cfg.enable_dp_attention:
# Normal case, use IPC within a single node
return PortArgs(
tokenizer_ipc_name=f"ipc://{tempfile.NamedTemporaryFile(delete=False).name}",
scheduler_input_ipc_name=f"ipc://{tempfile.NamedTemporaryFile(delete=False).name}",
detokenizer_ipc_name=f"ipc://{tempfile.NamedTemporaryFile(delete=False).name}",
nccl_port=nccl_port,
rpc_ipc_name=f"ipc://{tempfile.NamedTemporaryFile(delete=False).name}",
metrics_ipc_name=f"ipc://{tempfile.NamedTemporaryFile(delete=False).name}",
tokenizer_worker_ipc_name=tokenizer_worker_ipc_name,
decoupled_spec_ipc_config=decoupled_spec_ipc_config,
instance_id=instance_id,
)
else:
# DP attention. Use TCP + port to handle both single-node and multi-node.
if server_args.nnodes == 1 and server_args.dist_init_addr is None:
derived_port = server_args.port + ZMQ_TCP_PORT_DELTA
if derived_port > 65535:
derived_port = server_args.port - ZMQ_TCP_PORT_DELTA
na = NetworkAddress("127.0.0.1", derived_port)
else:
na = NetworkAddress.parse(server_args.dist_init_addr)
dist_init_host = na.host
dist_init_port = na.port
# Reserve port_base+0..NUM_DERIVED_PORTS-1 (6 fixed ports + dp_size
# rust-path slots); derive from server_args only (never dp_rank) so
# every init_new call agrees, decrementing below dist_init_port on
# overflow.
is_rust_server = envs.SGLANG_RUST_SERVER.get()
NUM_DERIVED_PORTS = 6 if not is_rust_server else 6 + cfg.dp_size
if server_args.is_ep_scale_joiner:
port_base = server_args.port + ZMQ_TCP_PORT_DELTA
if port_base + NUM_DERIVED_PORTS > 65535:
port_base = server_args.port - ZMQ_TCP_PORT_DELTA
elif dist_init_port + NUM_DERIVED_PORTS > 65535:
port_base = dist_init_port - NUM_DERIVED_PORTS - 1
else:
port_base = dist_init_port + 1
detokenizer_port = port_base + 1
rpc_port = port_base + 2
metrics_port = port_base + 3
load_collector_port = port_base + 5
if dp_rank is None:
# TokenizerManager to DataParallelController
scheduler_input_port = port_base + 4
elif is_rust_server:
# Rust server path (SGLANG_RUST_SERVER + dp attention): there is no
# DataParallelController allocating worker ports.
scheduler_input_port = port_base + 6 + dp_rank
else:
assert worker_ports is not None
scheduler_input_port = worker_ports[dp_rank]
is_joiner = server_args.is_ep_joiner
# Under SGLANG_DISTRIBUTED_INIT_METHOD_OVERRIDE, SGLang never binds
# dist_init_port / nccl_port (rendezvous uses the externally-managed
# store; see distributed/bootstrap.py:_resolve_dist_init_method), so
# their prechecks could only false-positive and are skipped.
dist_init_overridden = bool(
envs.SGLANG_DISTRIBUTED_INIT_METHOD_OVERRIDE.get()
)
try:
if dp_rank is None:
if not (is_joiner or dist_init_overridden):
wait_port_available(dist_init_port, "dist_init_port")
wait_port_available(port_base, "port_base")
wait_port_available(detokenizer_port, "detokenizer_port")
if not dist_init_overridden:
wait_port_available(nccl_port, "nccl_port")
wait_port_available(rpc_port, "rpc_port")
wait_port_available(metrics_port, "metrics_port")
if server_args.nnodes > 1:
wait_port_available(load_collector_port, "load_collector_port")
# Check scheduler_input_port only for dp.
# Skip check when using worker_ports since the port is already bound by our ZMQ socket
if dp_rank is None or worker_ports is None:
wait_port_available(scheduler_input_port, "scheduler_input_port")
except ValueError:
logger.exception(
f"Port is already in use. {dist_init_port=} {port_base=} {detokenizer_port=} {nccl_port=} {scheduler_input_port=}"
)
raise
return PortArgs(
tokenizer_ipc_name=NetworkAddress(dist_init_host, port_base).to_tcp(),
scheduler_input_ipc_name=NetworkAddress(
dist_init_host, scheduler_input_port
).to_tcp(),
detokenizer_ipc_name=NetworkAddress(
dist_init_host, detokenizer_port
).to_tcp(),
nccl_port=nccl_port,
rpc_ipc_name=NetworkAddress(dist_init_host, rpc_port).to_tcp(),
metrics_ipc_name=NetworkAddress(dist_init_host, metrics_port).to_tcp(),
tokenizer_worker_ipc_name=tokenizer_worker_ipc_name,
decoupled_spec_ipc_config=decoupled_spec_ipc_config,
load_collector_ipc_name=NetworkAddress(
dist_init_host, load_collector_port
).to_tcp(),
instance_id=instance_id,
)