Files
mgoinandClaude Fable 5 62a0750892 [Model] Add LongCat-2.0 (sparse attention, MTP, n-gram fixes)
Support meituan-longcat/LongCat-2.0-FP8: the LongCat-Flash-Lite backbone
plus a DeepSeek-V3.2-style sparse attention indexer, reusing vLLM's
existing DSA infrastructure.

- Resolve the checkpoint's null model_type via a registered config class
  (arch LongcatCausalLM); alias the oe_* n-gram config fields.
- Wire the indexer into the dual-attention layer: only the first
  attention of each layer computes top-k indices (cli_factor), the
  second reuses them via the shared buffer. Adds a generic skip_topk
  override to DeepseekV2MLAAttention; the schedule lives in the model.
- Streaming-aware indexing: force the first index_init_tokens and last
  index_local_tokens into the top-k set (sparse_attn_indexer).
- MTP speculative decoding (one module iterated up to 3 draft steps,
  plain token embedding, FP8 indexer weights).
- Fix a latent LongCat weight-loading bug: the post-load
  mla_scale_q_lora/kv_lora fold breaks under incremental load_weights
  calls; fold at weight-load time instead.
- Fix two n-gram embedding bugs (also affect LongCat-Flash-Lite):
  rebuild the left-context from the accepted-token history so rejected
  draft tokens don't pollute it, and hash EOS-current positions with
  full look-back per the HF reference (unit test included).
- Add --reasoning-parser longcat (<longcat_think> tags) and docs rows.
- Add longcat model types to the DeepGEMM Blackwell blocklist (non-ue8m0
  scales; measured GSM8K-neutral on vLLM but matches SGLang's guard).

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
Signed-off-by: mgoin <mgoin64@gmail.com>
2026-07-11 02:12:49 +00:00
..
2026-03-25 10:22:54 -07:00

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Welcome to vLLM

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Easy, fast, and cheap LLM serving for everyone

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vLLM is a fast and easy-to-use library for LLM inference and serving.

Originally developed in the Sky Computing Lab at UC Berkeley, vLLM has grown into one of the most active open-source AI projects built and maintained by a diverse community of many dozens of academic institutions and companies from over 2000 contributors.

Where to get started with vLLM depends on the type of user. If you are looking to:

  • Run open-source models on vLLM, we recommend starting with the Quickstart Guide
  • Build applications with vLLM, we recommend starting with the User Guide
  • Build vLLM, we recommend starting with Developer Guide

For information about the development of vLLM, see:

vLLM is fast with:

  • State-of-the-art serving throughput
  • Efficient management of attention key and value memory with PagedAttention
  • Continuous batching of incoming requests, chunked prefill, prefix caching
  • Fast and flexible model execution with piecewise and full CUDA/HIP graphs
  • Quantization: FP8, MXFP8/MXFP4, NVFP4, INT8, INT4, GPTQ/AWQ, GGUF, compressed-tensors, ModelOpt, TorchAO, and more
  • Optimized attention kernels including FlashAttention, FlashInfer, TRTLLM-GEN, FlashMLA, and Triton
  • Optimized GEMM/MoE kernels for various precisions using CUTLASS, TRTLLM-GEN, CuTeDSL
  • Speculative decoding including n-gram, suffix, EAGLE, DFlash
  • Automatic kernel generation and graph-level transformations using torch.compile
  • Disaggregated prefill, decode, and encode

vLLM is flexible and easy to use with:

  • Seamless integration with popular Hugging Face models
  • High-throughput serving with various decoding algorithms, including parallel sampling, beam search, and more
  • Tensor, pipeline, data, expert, and context parallelism for distributed inference
  • Streaming outputs
  • Generation of structured outputs using xgrammar or guidance
  • Tool calling and reasoning parsers
  • OpenAI-compatible API server, plus Anthropic Messages API and gRPC support
  • Efficient multi-LoRA support for dense and MoE layers
  • Support for NVIDIA GPUs, AMD GPUs, and x86/ARM/PowerPC CPUs. Additionally, diverse hardware plugins such as Google TPUs, Intel Gaudi, IBM Spyre, Huawei Ascend, Rebellions NPU, Apple Silicon, MetaX GPU, and more.

vLLM seamlessly supports 200+ model architectures on HuggingFace, including:

  • Decoder-only LLMs (e.g., Llama, Qwen, Gemma)
  • Mixture-of-Expert LLMs (e.g., Mixtral, DeepSeek-V3, Qwen-MoE, GPT-OSS)
  • Hybrid attention and state-space models (e.g., Mamba, Qwen3.5)
  • Multi-modal models (e.g., LLaVA, Qwen-VL, Pixtral)
  • Embedding and retrieval models (e.g., E5-Mistral, GTE, ColBERT)
  • Reward and classification models (e.g., Qwen-Math)

Find the full list of supported models here.

For more information, check out the following: