Auto Spec

Q: What is a Claude Code skill and how does the Auto Spec 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. Auto Spec is one of 67,000+ skills indexed in the open ClaudSkills catalog, classified under the General category. Learn more at https://claudskills.com/learn/what-is-skill-md/.

FeaturedCategory: General · Sub-category: automation · Last updated: 2026-07-18

Turn a raw feature request into a grounded, TESTABLE spec — autonomously. It recons the real repo and domain to ground every claim, drafts a spec (objectives, user-visible behavior, acceptance criteria, explicit non-goals, constraints, interfaces, risks), then runs a completeness-critic loop that adversarially hunts for gaps, ambiguity, and untestable criteria and fixes them until the spec is stable. Every acceptance criterion it emits is measurable (you could write a test for it); every requirement is grounded in the repo or flagged as an assumption — no invented requirements, no phantom paths. It writes `.ulpi/spec/<name>.md` and is the DEFINE phase that feeds auto-plan. Composes fan-out-work (recon), adversarial-verify (the critic), converge-loop (until-stable), and checkpoint-resume.

Security AStatic scan found no risk patternsHow grading works ›

About this skill (catalog notes)

Auto Spec is published as a SKILL.md file in this catalog. The SKILL.md runs to about 1,225 words, in the catalog's typical mid-range.

Source: ulpi-io.github.io/skills-autonomous-engineering
Original author: ulpi-io
Indexed lastmod: 2026-07-18
Catalog position: General · automation
Indexed related skills: 10

How Auto Spec fits the catalog

Auto Spec sits in the General category under the automation sub-topic in the ClaudSkills catalog. There are 10 related skills indexed alongside it; comparing a few before installing usually reveals which fits your workflow best.

These notes are auto-generated from features detected in the SKILL.md file and from this catalog's structure — they aren't part of the source repository.

From the source SKILL.md

<EXTREMELY-IMPORTANT> A spec is a contract; a vague or invented one poisons everything downstream. Non-negotiable: 1. GROUND EVERY REQUIREMENT. Each requirement is tied to the actual repo/domain or explicitly marked an ASSUMPTION. Never invent requirements, file paths, endpoints, or constraints to fill a gap — a phantom in the spec becomes a phantom in the plan and the code. 2. EVERY ACCEPTANCE CRITERION MUST BE TESTABLE. If you can't state how it would be verified (a test, a measurable threshold, an observable behavior), it isn't an acceptance criterion — sharpen it or cut it. 3. SCOPE HAS…

What this skill does

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

Who uses this skill

The Auto Spec Claude Code skill is built for Claude Code users and developers across all disciplines looking for general-purpose AI assistance. It's part of ClaudSkills (also referred to as Claude Skills or Claude Code Skills) — the open community-curated registry of 153,000+ 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/auto-spec
curl -L https://claudskills.com/skills/auto-spec/SKILL.md \
  -o ~/.claude/skills/auto-spec/SKILL.md

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

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

📱 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 Auto Spec Claude Code skill?

Install via the ClaudSkills desktop app (one click) or copy SKILL.md from the source repository to ~/.claude/skills/auto-spec/SKILL.md and restart Claude Code. Both flows are detailed at claudskills.com/install/.

What does the Auto Spec skill do?

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 Auto Spec skill?

Use Auto Spec when your Claude Code task falls under the General category — specifically in the automation 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 Auto Spec" or describe the task and let Claude pick). Browse related skills at /category/general/.

What is a Claude Code skill and how does the Auto Spec 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. Auto Spec is one of 67,000+ skills indexed in the open ClaudSkills catalog, classified under the General category. Learn more at /learn/what-is-a-claude-skill/.

Attribution & license

Source: https://github.com/ulpi-io/skills-autonomous-engineering/blob/HEAD/auto-spec/SKILL.md
Author: ulpi-io
Website: https://ulpi-io.github.io/skills-autonomous-engineering

Cite this skill

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

APA

ulpi-io. (2026). Auto Spec [Claude Code skill]. ClaudSkills. https://claudskills.com/skills/auto-spec/

BibTeX

@misc{auto-spec-2026,
  author    = {ulpi-io},
  title     = {Auto Spec [Claude Code skill]},
  year      = {2026},
  publisher = {ClaudSkills},
  url       = {https://claudskills.com/skills/auto-spec/}
}

Embed this skill

Promote, attribute, or link this skill from your own README, blog post, or documentation. All three snippets are free to use — no sign-up, no API key. More distribution surfaces →

Badge

[![ClaudSkills](https://claudskills.com/badge/auto-spec.svg)](https://claudskills.com/skills/auto-spec/?utm_source=badge&utm_medium=readme&utm_campaign=skill_badge)

Security scan

Grade A · scanned 2026-07-18 — free static scan against the OWASP Agentic Skills Top 10.

No risk patterns were found in any of the ten OWASP-aligned categories. How grading works ›

✓ Prompt injection
✓ Data exfiltration
✓ Supply chain
✓ Reverse shell
✓ Credentials
✓ Execution
✓ Filesystem
✓ Persistence
✓ Obfuscation
✓ Network

Show this grade on your repo (click to copy):

[![Security: A](https://img.shields.io/badge/Security-A-2e7d32)](https://claudskills.com/skills/auto-spec/#security)

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Browse all General skills → Top 100 skills

Part of ClaudSkills — the open registry for Claude Skills & Claude Code Skills. · What's New · Install guide · About · llms.txt

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