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SGLang

Serving engine tuned for prefix reuse and structured output

OfficialApache-2.0
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4.9k
Last commit
15 Aug 2026

Overview

Its prefix cache pays off precisely in the agent case, where many calls share a long, identical system prompt. Also strong at constrained decoding when responses must match a schema. The main alternative in this space is vLLM; benchmark both on your own traffic shape.

What can you do with SGLang?

  • Reuse a shared system prompt — RadixAttention prefix caching retains the KV state for identical leading tokens, so repeated agent calls that all carry one long system prompt skip recomputing it.
  • Constrain output to a schema — Constrained decoding forces generated responses to match a supplied schema instead of relying on retries to repair malformed tool-call JSON.
  • Run it beyond NVIDIA GPUs — The PyPI package is sglang, and besides NVIDIA GB200/B300/H100/A100 the runtime targets AMD MI355/MI300, Intel Xeon CPUs, Google TPUs and Ascend NPUs.
  • Reach it with an OpenAI client — The server is compatible with OpenAI APIs and with most Hugging Face models, so code already written against the OpenAI SDK reaches it without a rewrite.
  • Reuse the engine for RL rollouts — SGLang has native RL integrations and is used as the rollout backend by post-training frameworks including AReaL, Miles, slime, Tunix and verl.

Documentation

Reproduced from the sgl-project/sglang README, published under Apache-2.0. Read the original ↗

News

  • [2026/07] 🔥 SGLang and Miles add day-0 support for Kimi K3 (blog).
  • [2026/07] RadixArk and Google bring full SGLang features to TPUs (blog).
  • [2026/07] Serving GLM5.2 NVFP4 agentic workloads with SGLang: Reaching 500 TPS in two weeks (blog).
  • [2026/06] 🔥 The next generation of speculative decoding: DFlash and Spec V2 (blog).
  • [2026/06] SGLang provides day-0 support for latest open models (Nemotron 3 Ultra, Nemotron 3 Super, Higgs Audio v3 TTS).
  • [2026/04] 🔥 DeepSeek-V4 on Day 0: From Fast Inference to Verified RL with SGLang and Miles (blog).
  • [2026/02] 🔥 Unlocking 25x Inference Performance with SGLang on NVIDIA GB300 NVL72 (blog).
  • [2026/01] SGLang Diffusion accelerates video and image generation (blog).
  • [2025/12] SGLang provides day-0 support for latest open models (MiMo-V2-Flash, Nemotron 3 Nano, Mistral Large 3, LLaDA 2.0 Diffusion LLM, MiniMax M2).
  • [2025/11] SGLang Diffusion accelerates video and image generation (blog).
  • [2025/10] SGLang now runs natively on TPU with the SGLang-Jax backend (blog).
  • [2025/10] PyTorch Conference 2025 SGLang Talk (slide).
  • [2025/10] SGLang x Nvidia SF Meetup on 10/2 (recap).
  • [2025/09] Deploying DeepSeek on GB200 NVL72 with PD and Large Scale EP (Part II): 3.8x Prefill, 4.8x Decode Throughput (blog).
  • [2025/09] SGLang Day 0 Support for DeepSeek-V3.2 with Sparse Attention (blog).
  • [2025/08] SGLang x AMD SF Meetup on 8/22: Hands-on GPU workshop, tech talks by AMD/xAI/SGLang, and networking (Roadmap, Large-scale EP, Highlights, AITER/MoRI, Wave).
  • [2025/08] SGLang provides day-0 support for OpenAI gpt-oss model (instructions)
  • [2025/06] SGLang, the high-performance serving infrastructure powering trillions of tokens daily, has been awarded the third batch of the Open Source AI Grant by a16z (a16z blog).
  • [2025/06] Deploying DeepSeek on GB200 NVL72 with PD and Large Scale EP (Part I): 2.7x Higher Decoding Throughput (blog).
  • [2025/05] Deploying DeepSeek with PD Disaggregation and Large-scale Expert Parallelism on 96 H100 GPUs (blog).
  • [2025/03] Supercharge DeepSeek-R1 Inference on AMD Instinct MI300X (AMD blog)
  • [2025/03] SGLang Joins PyTorch Ecosystem: Efficient LLM Serving Engine (PyTorch blog)
  • [2025/02] Unlock DeepSeek-R1 Inference Performance on AMD Instinct™ MI300X GPU (AMD blog)
  • [2025/01] SGLang provides day one support for DeepSeek V3/R1 models on NVIDIA and AMD GPUs with DeepSeek-specific optimizations. (instructions, AMD blog, 10+ other companies)
  • [2024/12] v0.4 Release: Zero-Overhead Batch Scheduler, Cache-Aware Load Balancer, Faster Structured Outputs (blog).
  • [2024/10] The First SGLang Online Meetup (slides).
  • [2024/09] v0.3 Release: 7x Faster DeepSeek MLA, 1.5x Faster torch.compile, Multi-Image/Video LLaVA-OneVision (blog).
  • [2024/07] v0.2 Release: Faster Llama3 Serving with SGLang Runtime (vs. TensorRT-LLM, vLLM) (blog).
  • [2024/02] SGLang enables 3x faster JSON decoding with compressed finite state machine (blog).
  • [2024/01] SGLang provides up to 5x faster inference with RadixAttention (blog).
  • [2024/01] SGLang powers the serving of the official LLaVA v1.6 release demo (usage).

About

SGLang is a high-performance serving framework for large language models and multimodal models. It is designed to deliver low-latency and high-throughput inference across a wide range of setups, from a single GPU to large distributed clusters. Its core features include:

  • Fast Runtime: Provides efficient serving with RadixAttention for prefix caching, a zero-overhead CPU scheduler, prefill-decode disaggregation, speculative decoding, continuous batching, paged attention, tensor/pipeline/expert/data parallelism, structured outputs, chunked prefill, quantization (FP4/FP8/INT4/AWQ/GPTQ), and multi-LoRA batching.
  • Broad Model Support: Supports a wide range of language models (Llama, Qwen, DeepSeek, Kimi, GLM, GPT, Gemma, Mistral, etc.), embedding models (e5-mistral, gte, mcdse), reward models (Skywork), and diffusion models (WAN, Qwen-Image), with easy extensibility for adding new models. Compatible with most Hugging Face models and OpenAI APIs.
  • Extensive Hardware Support: Runs on NVIDIA GPUs (GB200/B300/H100/A100/Spark/5090), AMD GPUs (MI355/MI300), Intel Xeon CPUs, Google TPUs, Ascend NPUs, and more.
  • Active Community: SGLang is open-source and supported by a vibrant community with widespread industry adoption, powering over 400,000 GPUs worldwide.
  • RL & Post-Training Backbone: SGLang is a proven rollout backend used for training many frontier models, with native RL integrations and adoption by well-known post-training frameworks such as AReaL, Miles, slime, Tunix, verl and more.

Getting Started

Benchmark and Performance

Learn more in the release blogs: v0.2 blog, v0.3 blog, v0.4 blog, Large-scale expert parallelism, GB200 rack-scale parallelism, GB300 long context.

Adoption and Sponsorship

SGLang has been deployed at large scale, generating trillions of tokens in production each day. It is trusted and adopted by a wide range of leading enterprises and institutions, including xAI, NVIDIA, AMD, Intel, LinkedIn, Cursor, Oracle Cloud, Google Cloud, Microsoft Azure, AWS, Atlas Cloud, Voltage Park, Nebius, DataCrunch, Novita, RunPod, InnoMatrix, Modal, MIT, UCLA, the University of Washington, Stanford, UC Berkeley, Tsinghua University, Baseten, Baidu, AntGroup, Alibaba, Tencent, and other major technology organizations. As an open-source LLM inference engine, SGLang has become the de facto industry standard, with deployments running on over 400,000 GPUs worldwide. SGLang is currently hosted under the non-profit open-source organization LMSYS.

Contact Us

For enterprises interested in adopting or deploying SGLang at scale, including technical consulting, sponsorship opportunities, or partnership inquiries, please contact us at sglang@lmsys.org.

Long-term active SGLang contributors are eligible for coding agent sponsorship, such as Cursor, Claude Code, or OpenAI Codex. Email sglang@lmsys.org with your most important commits or pull requests.