Agent skill

Flash Attention Kernel

by ZJLi2013 in ZJLi2013/awesome-kernel-skills

Optimize FlashAttention-style fused attention kernels in Triton for NVIDIA and AMD GPUs.

No licenceAuto-check passed

Install Flash Attention Kernel

skills CLI
$ npx skills add ZJLi2013/awesome-kernel-skills --skill flash-attention-kernel -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI
$ gh skill install ZJLi2013/awesome-kernel-skills flash-attention-kernel --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy
$ git clone --depth 1 https://github.com/ZJLi2013/awesome-kernel-skills.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/kernels/flash-attention .claude/skills/flash-attention-kernel && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Facts

Skill name
flash-attention-kernel
GitHub stars
102
Token cost
~697 tokens
SKILL.md length
302 words
Files
3
Skills in repo
12
Repo updated
First seen
Licence
None found

At a glance

Optimize FlashAttention-style fused attention kernels in Triton for NVIDIA and AMD GPUs.

  • Works in 3 steps: Maintain running m_i (row max) and l_i… → For each K tile: compute qk = Q @ K^T,… → After all K tiles: divide accumulator by…
  • Optimizing self-attention
  • SKILL.md covers Overview, Core Technique, Autotune Notes and Verification, plus 2 more sections
  • Runs Python scripts from its folder; calls python

What it does

Flash Attention Kernel is an agent skill from ZJLi2013/awesome-kernel-skills. Optimize FlashAttention-style fused attention kernels in Triton for NVIDIA and AMD GPUs. Covers online softmax, tiled QK/AV GEMM, causal masking, and memory-efficient attention. Use when writing or optimizing self-attention, cross-attention, or any QKV attention kernel.

Its SKILL.md is about 700 tokens, which your agent loads only when the skill is triggered. The skill folder holds 2 other files (for example `test_flash_attention.py` and `triton_template.py`).

It works with NVIDIA AI Platform.

When your agent uses it

  • Optimizing self-attention
  • Cross-attention
  • Any QKV attention kernel

Example prompts

  • “/flash-attention-kernel”

Requirements

  • Python 3

Workflow steps

3 steps, taken from the first numbered list in SKILL.md.

  1. Maintain running m_i (row max) and l_i (exp sum) per query row
  2. For each K tile: compute qk = Q @ K^T, update max, rescale accumulator
  3. After all K tiles: divide accumulator by final l_i

What it can do on your machine

Read from SKILL.md and the folder at commit aba7662. It shows what the files ask for, not the result of running them.

  • Tool permissions

    Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

    From allowed-tools in the SKILL.md frontmatter.

  • Runs code

    Ships script files (Python), which the agent can run.

    Shell commands in SKILL.md call:

    • python

    From the folder's file list and the shell code blocks in SKILL.md.

  • Network

    Links to these hosts (documentation or services it may open):

    • arxiv.org
    • triton-lang.org

    From URLs in SKILL.md, links to its own repository left out.

  • Credentials

    Names no API keys, tokens, secrets or passwords.

    From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Flash Attention Kernel loads about 697 tokens when it runs. Until then it costs about 73 tokens; SKILL.md has 302 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it
~73
When it runs · the whole SKILL.md, loaded when a task matches
~697

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

Without a licence we can't republish the file, so here is its outline and opening line. It has 302 words (~697 tokens).

“FlashAttention fuses the entire attention computation (Q@K^T -> softmax -> @V) into a single kernel, avoiding materialization of the full N x N attention matrix in HBM.”

— opening of SKILL.md by ZJLi2013
name
flash-attention-kernel

Read the full SKILL.md on GitHub

Files

SKILL.md and 2 other files in skills/kernels/flash-attention of ZJLi2013/awesome-kernel-skills.

  • SKILL.md
  • test_flash_attention.py
  • triton_template.py

Open the folder on GitHubat commit aba7662

Compare with similar skills

Flash Attention Kernel next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Flash Attention Kernel compared with similar skills
SkillStarsUsed inTokensAuto-checkLicenceRepo updated
Flash Attention Kernel this skillZJLi2013/awesome-kernel-skills102—~697Automated safety check: PassNone
LLM Torch Profiler Analysissgl-project/sglang37k2 repos~6.4kAutomated safety check: PassApache-2.0
Skill InspectorNVIDIA/SkillSpector20k—~1.8kAutomated safety check: PassApache-2.0
Megatron-LM Container and Dependency SetupNVIDIA/Megatron-LM18k—~2.6kAutomated safety check: PassApache-2.0
Embeddings via 9Routerdecolua/9router30k—~604Automated safety check: PassMIT
Megatron-LM Base Image BumpNVIDIA/Megatron-LM18k—~2.8kAutomated safety check: PassApache-2.0

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  • Gemm Kernel Optimization

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  • Iterative Kernel Optimization Loop

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  • Kernel Benchmark

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  • Kernel Profiling

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Questions about Flash Attention Kernel

What does Flash Attention Kernel do?

Optimize FlashAttention-style fused attention kernels in Triton for NVIDIA and AMD GPUs. Flash Attention Kernel is an agent skill from ZJLi2013/awesome-kernel-skills. Optimize FlashAttention-style fused attention kernels in Triton for NVIDIA and AMD GPUs.

When should I use Flash Attention Kernel?

Flash Attention Kernel fits situations like: optimizing self-attention; cross-attention; any QKV attention kernel.

How do I install Flash Attention Kernel in Claude Code?

Run `npx skills add ZJLi2013/awesome-kernel-skills --skill flash-attention-kernel -a claude-code`. Or copy the skill folder (skills/kernels/flash-attention in ZJLi2013/awesome-kernel-skills) into .claude/skills/flash-attention-kernel in your project. Claude Code loads it when a task matches its description.

How do I install Flash Attention Kernel in Codex?

Run `npx skills add ZJLi2013/awesome-kernel-skills --skill flash-attention-kernel -a codex`. Or copy the skill folder (skills/kernels/flash-attention in ZJLi2013/awesome-kernel-skills) into .agents/skills/flash-attention-kernel in your project. Codex loads it when a task matches its description.

Can I use Flash Attention Kernel in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add ZJLi2013/awesome-kernel-skills --skill flash-attention-kernel -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/flash-attention-kernel, .gemini/skills/flash-attention-kernel, .github/skills/flash-attention-kernel and .opencode/skills/flash-attention-kernel in your project.

What does Flash Attention Kernel need to run?

Going by SKILL.md and its folder, Flash Attention Kernel needs Python for the scripts in its folder and the command-line tools its instructions call (python). Our summary lists: Python 3.

Does Flash Attention Kernel access the network?

SKILL.md names 2 domains. As links in the text: arxiv.org and triton-lang.org. This is read from the text; nothing was executed.

Is Flash Attention Kernel safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does Flash Attention Kernel use?

No licence was found for Flash Attention Kernel or its repository. Without one, default copyright applies: ask the author before reusing or redistributing it.

How many tokens does Flash Attention Kernel use?

About 697 tokens (SKILL.md is roughly 2.8k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.

What are the alternatives to Flash Attention Kernel?

Skills that share tags, products or a category with Flash Attention Kernel: LLM Torch Profiler Analysis (sgl-project/sglang, 37k stars), Skill Inspector (NVIDIA/SkillSpector, 20k stars), Megatron-LM Container and Dependency Setup (NVIDIA/Megatron-LM, 18k stars) and Embeddings via 9Router (decolua/9router, 30k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Flash Attention Kernel?

ZJLi2013 (a GitHub user) maintains it in ZJLi2013/awesome-kernel-skills, which has 102 GitHub stars. The repository holds 12 skills in this directory. The repository was last updated on March 31, 2026.

Source: ZJLi2013/awesome-kernel-skills on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.