---
id: pr-vllm-34478
repo: vllm-project/vllm
pr: 34478
title: '[Model] Add NVFP4 quantization support for Step3.5-Flash'
author: tacos8me
date: '2026-02-22'
url: https://github.com/vllm-project/vllm/pull/34478
source_category: upstream-code
architectures:
- sm100
tags:
- fp4
- kernel-fusion
- moe
- nvfp4
- quantization
techniques:
- kernel-fusion
hardware_features:
- fp4
- nvfp4
kernel_types:
- moe
- quantization
languages:
- python
captured_at: '2026-04-27'
status: merged
merge_sha: b7892a3beff05971f7e1ed3519aec96c3d89bfb0
inclusion_reason: kernel file changes
changed_paths:
- tests/kernels/moe/test_nvfp4_moe.py
- vllm/model_executor/layers/fused_moe/cutlass_moe.py
- vllm/model_executor/layers/fused_moe/fused_marlin_moe.py
- vllm/model_executor/layers/quantization/compressed_tensors/compressed_tensors_moe.py
- vllm/model_executor/models/step3p5.py
head_ref_oid: 384851ba31b1b12f0bb668928c2b35a8bd6d4dcd
artifact_dir: evidence/pull-bundles/vllm/gh-34478
---
# [Model] Add NVFP4 quantization support for Step3.5-Flash

- Repository: `vllm-project/vllm`
- PR: [34478](https://github.com/vllm-project/vllm/pull/34478)
- Decision: `kernel file changes`
- Reason: kernel file changes

## Changed Paths

- `tests/kernels/moe/test_nvfp4_moe.py`
- `vllm/model_executor/layers/fused_moe/cutlass_moe.py`
- `vllm/model_executor/layers/fused_moe/fused_marlin_moe.py`
- `vllm/model_executor/layers/quantization/compressed_tensors/compressed_tensors_moe.py`
- `vllm/model_executor/models/step3p5.py`

## Evidence Bundle

`evidence/pull-bundles/vllm/gh-34478`
