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Atdd Mutate

Category: Engineering  ·  Sub-category: testing  ·  Last updated:
This skill should be used when the user asks to "run mutation testing", "mutate my code", "kill mutants", "check test quality", "find surviving mutants", "verify test effectiveness with mutations", "run stryker", "run mutmut", "run pitest", "set up mutation testing", "how good are my tests", "are my tests catching bugs", or mentions mutation testing, mutation score, or mutant survival in the context of testing. It adds a third validation layer to the ATDD workflow: after acceptance tests verify WHAT and unit tests verify HOW, mutation testing verifies that tests actually catch bugs.
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From the source SKILL.md

Add a third validation layer to the ATDD two-stream testing approach. Acceptance tests verify WHAT, unit tests verify HOW, mutation testing verifies that the tests actually catch bugs.

What this skill does

Atdd Mutate is a community-contributed Claude Code skill in the testing sub-category. It ships as a SKILL.md file that Claude Code auto-discovers under ~/.claude/skills/atdd-mutate/ and loads when your prompt matches the skill's trigger.

Who uses this skill

The Atdd Mutate Claude Code skill is built for software engineers, backend developers, full-stack teams, and technical leads building and maintaining production systems. It's part of ClaudSkills (also referred to as Claude Skills or Claude Code Skills) — the open community-curated registry of 158,000+ SKILL.md files for Anthropic's Claude Code agent and the wider Claude ecosystem (Claude API, Claude Agent SDK).

How to install

Free

Manual install (2 steps)

mkdir -p ~/.claude/skills/atdd-mutate
curl -L https://claudskills.com/skills/atdd-mutate/SKILL.md \
  -o ~/.claude/skills/atdd-mutate/SKILL.md

Or just download SKILL.md directly and drop it into ~/.claude/skills/atdd-mutate/. Claude Code auto-discovers it on next session.

Skills live at ~/.claude/skills/atdd-mutate/SKILL.md on macOS/Linux, or %USERPROFILE%\.claude\skills\atdd-mutate\SKILL.md on Windows. See the full install guide for step-by-step instructions.

Telegram

📱 Install from your phone or desktop Telegram

Open @claudskills_bot on Telegram, tap Open Desktop App, and the desktop app installs this skill for you. Or share the bot link with a colleague — they get the same one-tap install. Learn more →

Pro

One-click install via the desktop app

The ClaudSkills desktop app installs any skill directly into ~/.claude/skills/ with one click — no terminal required. Pro starts at $9/mo or $149 lifetime.

Pro

For the full experience including quality scoring and one-click install features for each skill — upgrade to Pro.

See pricing → Download desktop app

Frequently asked questions

How do I install the Atdd Mutate Claude Code skill?
Install via the ClaudSkills desktop app (one click) or copy SKILL.md from the source repository to ~/.claude/skills/atdd-mutate/SKILL.md and restart Claude Code. Both flows are detailed at claudskills.com/install/.
What does the Atdd Mutate skill do?
This skill should be used when the user asks to "run mutation testing", "mutate my code", "kill mutants", "check test quality", "find surviving mutants", "verify test effectiveness with mutations", "run stryker", "run mutmut", "run pitest", "set up mutation testing", "how good are my tests", "are my tests catching bugs", or mentions mutation testing, mutation score, or mutant survival in the context of testing. It adds a third validation layer to the ATDD workflow: after acceptance tests verify WHAT and unit tests verify HOW, mutation testing verifies that tests actually catch bugs.
Is this skill free to install?
Yes. ClaudSkills is an open registry — every skill keeps its source repository's license, and manual install via copy is free. ClaudSkills Pro ($9/mo, $79/yr, or $149 one-time) adds one-click install via the desktop app and a multi-signal Quality Score.
When should I use the Atdd Mutate skill?
Use Atdd Mutate when your Claude Code task falls under the Engineering category — specifically in the testing area. Claude Code auto-discovers installed skills and invokes the right one based on the task description, so you can also ask Claude directly (e.g. "use Atdd Mutate" or describe the task and let Claude pick). Browse related skills at /category/engineering/.
What is a Claude Code skill and how does the Atdd Mutate skill fit in?
A Claude Code skill is a SKILL.md file that lives under ~/.claude/skills/<name>/ and tells the Claude Code CLI agent how to perform a specific task (instructions, prompts, allowed tools). Skills are auto-discovered at session start. Atdd Mutate is one of 67,000+ skills indexed in the open ClaudSkills catalog, classified under the Engineering category. Learn more at /learn/what-is-a-claude-skill/.

Attribution & license

Cite this skill

If you reference this skill in a blog post, paper, or documentation, you can cite it as:

APA
kdoronin. (2026). Atdd Mutate [Claude Code skill]. ClaudSkills. https://claudskills.com/skills/atdd-mutate/
BibTeX
@misc{atdd-mutate-2026,
  author    = {kdoronin},
  title     = {Atdd Mutate [Claude Code skill]},
  year      = {2026},
  publisher = {ClaudSkills},
  url       = {https://claudskills.com/skills/atdd-mutate/}
}

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