spec-author

spec-author is a skill for Claude Code, Codex from hams-ollo/zen-agent-skills. It costs 133 tokens per session (2,269 once invoked), scanned A, original, MIT.

A specification-writing skill that turns a rough feature idea or bug report into a lasting description of expected behavior. It records goals, limits, constraints, questions, and Given/When/Then scenarios with stable IDs.

In plain words
What is it for?
Use it before breaking work into tasks when the desired behavior needs to be made explicit.
Why use it?
It gives later implementation and testing work a shared contract instead of relying on an informal request. It stops after drafting the spec for approval.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: installed under .agents/ (shared by several agents).

Good fit Use it before breaking work into tasks when the desired behavior needs to be made explicit.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/hams-ollo/zen-agent-skills/spec-author
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add hams-ollo/zen-agent-skills --skill spec-author
Clone the repo
git clone --depth 1 https://github.com/hams-ollo/zen-agent-skills

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for spec-author

README.md
[![agentmods](https://agentmods.dev/badge/skills/hams-ollo/zen-agent-skills/spec-author/github.svg)](https://agentmods.dev/skills/hams-ollo/zen-agent-skills/spec-author)
Your own site
<a href="https://agentmods.dev/skills/hams-ollo/zen-agent-skills/spec-author"><img src="https://agentmods.dev/badge/skills/hams-ollo/zen-agent-skills/spec-author/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for spec-author

Your own site · 80×15
<a href="https://agentmods.dev/skills/hams-ollo/zen-agent-skills/spec-author"><img src="https://agentmods.dev/badge/skills/hams-ollo/zen-agent-skills/spec-author.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 133 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,269 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00133 $0.02269
Opus 5 $0.00067 $0.01135
Sonnet 5 $0.00027 $0.00454
Haiku 4.5 $0.00013 $0.00227

Measured 5d ago against content hash 81e915407829, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

spec-author scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 5d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.agents/skills/spec-author/SKILL.md · 195 lines

How it starts

The opening of the file, as written. The whole thing — 195 lines — stays where its author put it; the contents beside it link to each section on GitHub.

spec-author

Draft a durable behavioral contract from a raw idea, then stop. This is the front of the contract-driven spine: spec-author writes the spec, a human approves it, new-task decomposes it into tasks, and the rest of the spine builds and verifies against it. A spec says what should be true and why it matters. It is not a plan, an architecture brief, a task list, or a test design.

This skill composes the spec-quality lens: it drafts, then checks its own draft against that lens and revises until the verdict is ready, rather than restating the lens's rules here. Keep the two in sync by pointing at the lens, not copying it.

When to use

  • A rough idea, feature request, or bug needs a durable contract before work starts.
  • You are about to reach for new-task but there is no spec capturing the intended behavior yet.
  • An existing spec needs revision back to a ready state.

When not to use

  • The work is a single, obvious, atomic change with no behavioral ambiguity: go straight to new-task.
  • You only need to review an existing spec, not author one: use spec-quality directly.
  • You are decomposing an already-approved spec into tasks: that is new-task.

Inputs

Required:

  • Source request: the raw idea, feature request, or bug to turn into a spec.

Optional:

  • Repository context: existing names, tools, commands, surfaces, and conventions the spec should ground its wording in rather than inventing new terms.

Where the spec goes

Find the repository's spec location before writing, do not assume one. Look for an existing spec directory under any of its common names (docs/spec/, specs/, docs/rfcs/, design/) and for how the specs already there are named. Match what you find.

Only when a repository has none of these does docs/spec/<slug>.md apply, as this kit's default. Writing there regardless is how a repo ends up with two spec directories, and the second one is the one nobody reads. If the convention is ambiguous, ask; it is a one-line question and the answer is durable.

Read the full file on GitHub · 195 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 5d ago Changed · +7 lines 81e915407829
  2. 9d ago First seen · 188 lines · 133 tokens per session scan A e8e848271d32

Subscribe to this mod's changes

spec-author is a skill published in the GitHub repository hams-ollo/zen-agent-skills (2 stars, last pushed 7d ago), licensed MIT. It adds 133 tokens to every session and 2,269 once invoked, about $0.0007 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.