---
id: pr-sglang-13539
repo: sgl-project/sglang
pr: 13539
title: add the fa4 mm backend and varlen func
author: vincentzed
date: '2026-01-23'
url: https://github.com/sgl-project/sglang/pull/13539
source_category: upstream-code
architectures:
- sm100
tags: []
techniques: []
hardware_features: []
kernel_types: []
languages: []
captured_at: '2026-05-16'
status: merged
merge_sha: 08fcda2f634ac705226ee95d2cd05b86f69c6fe1
inclusion_reason: defer
changed_paths:
- docs/advanced_features/attention_backend.md
- docs/advanced_features/server_arguments.md
- python/sglang/srt/layers/attention/vision.py
- python/sglang/srt/server_args.py
artifact_dir: evidence/pull-bundles/sglang/gh-13539
head_ref_oid: 1ac5b0ebe001cafc6325a57ad49cb5058fd86d92
---
# add the fa4 mm backend and varlen func

- Repository: `sgl-project/sglang`
- PR: [13539](https://github.com/sgl-project/sglang/pull/13539)
- Decision: `defer`
- Reason: defer

## Changed Paths

- `docs/advanced_features/attention_backend.md`
- `docs/advanced_features/server_arguments.md`
- `python/sglang/srt/layers/attention/vision.py`
- `python/sglang/srt/server_args.py`

## Evidence Bundle

`evidence/pull-bundles/sglang/gh-13539`
