---
id: pr-vllm-20401
repo: vllm-project/vllm
pr: 20401
title: Add tree attention backend for v1 (part 1)
author: TheEpicDolphin
date: '2025-08-04'
url: https://github.com/vllm-project/vllm/pull/20401
source_category: upstream-code
architectures:
- sm100
tags: []
techniques: []
hardware_features: []
kernel_types: []
languages: []
captured_at: '2026-05-16'
status: merged
merge_sha: aa7012eb6db69baab57c80ac596d088eb81e090f
inclusion_reason: defer
changed_paths:
- tests/v1/attention/test_attention_backends.py
- tests/v1/attention/utils.py
- tests/v1/spec_decode/test_eagle.py
- tests/v1/spec_decode/test_tree_attention.py
- vllm/attention/ops/triton_unified_attention.py
- vllm/config.py
- vllm/engine/arg_utils.py
- vllm/platforms/cuda.py
- vllm/platforms/interface.py
- vllm/v1/attention/backends/tree_attn.py
- vllm/v1/attention/backends/utils.py
- vllm/v1/spec_decode/eagle.py
artifact_dir: evidence/pull-bundles/vllm/gh-20401
head_ref_oid: bd28741b3eb74ab70be818ac5a970da56c5638c3
---
# Add tree attention backend for v1 (part 1)

- Repository: `vllm-project/vllm`
- PR: [20401](https://github.com/vllm-project/vllm/pull/20401)
- Decision: `defer`
- Reason: defer

## Changed Paths

- `tests/v1/attention/test_attention_backends.py`
- `tests/v1/attention/utils.py`
- `tests/v1/spec_decode/test_eagle.py`
- `tests/v1/spec_decode/test_tree_attention.py`
- `vllm/attention/ops/triton_unified_attention.py`
- `vllm/config.py`
- `vllm/engine/arg_utils.py`
- `vllm/platforms/cuda.py`
- `vllm/platforms/interface.py`
- `vllm/v1/attention/backends/tree_attn.py`
- `vllm/v1/attention/backends/utils.py`
- `vllm/v1/spec_decode/eagle.py`

## Evidence Bundle

`evidence/pull-bundles/vllm/gh-20401`
