Tencent has released Simple Attention Sparsification (SAS) checkpoints that learn to rank and select KV blocks for each query in Qwen3 models. Unlike methods distilling dense attention scores, SAS adds continuous gates to selected blocks, enabling end-to-end optimization of context ranking with the language-modeling loss.

  • The release includes gate-router checkpoints for Qwen3-4B, Qwen3-8B, and Qwen3-14B models.
  • These are router-only weights that require a corresponding public Qwen3 base model and the seer_attn backend in a fork of SGLang.
  • The default sparse-attention setup uses a 2,048-token decode budget, but checkpoints can be evaluated with 1,024-, 2,048-, or 4,096-token budgets without retraining.

The checkpoints allow users to serve an OpenAI-compatible API using the seer_attn backend for efficient inference.