ac-writer

ac-writer is a skill for Claude Code from Harshvardhan86/claude-wave-plugin. It costs 45 tokens per session (855 once invoked), scanned A, original, MIT.

A writing guide for creating acceptance criteria: specific statements that a real browser test or command can prove true or false. Each statement describes an action, an observable result, and a case that must fail.

In plain words
What is it for?
Use it to define testable requirements for feature work before implementation, including visible effects, element size, and rejected or invalid behavior.
Why use it?
It replaces vague requirements such as “the UI works” with checks that reveal whether a feature is actually correct. It also requires visual checks for user-interface changes.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin. Also seen: mentions CLAUDE.md.

Part of the claude-wave-plugin plugin — 7 skills, 2 commands shipped together

Good fit Use it to define testable requirements for feature work before implementation, including visible effects, element size, and rejected or invalid behavior.

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Install with agentmods
npx agentmods add skills/harshvardhan86/claude-wave-plugin/ac-writer
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 Harshvardhan86/claude-wave-plugin --skill ac-writer
Clone the repo
git clone --depth 1 https://github.com/Harshvardhan86/claude-wave-plugin

Made for: Claude Code.

Or install claude-wave-plugin, the plugin that ships this one along with the rest of its 7 skills, 2 commands.

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 ac-writer

README.md
[![agentmods](https://agentmods.dev/badge/skills/harshvardhan86/claude-wave-plugin/ac-writer/github.svg)](https://agentmods.dev/skills/harshvardhan86/claude-wave-plugin/ac-writer)
Your own site
<a href="https://agentmods.dev/skills/harshvardhan86/claude-wave-plugin/ac-writer"><img src="https://agentmods.dev/badge/skills/harshvardhan86/claude-wave-plugin/ac-writer/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 ac-writer

Your own site · 80×15
<a href="https://agentmods.dev/skills/harshvardhan86/claude-wave-plugin/ac-writer"><img src="https://agentmods.dev/badge/skills/harshvardhan86/claude-wave-plugin/ac-writer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 45 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 855 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. 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 $0.00045 $0.00855
Opus 5 $0.00023 $0.00428
Sonnet 5 $0.00009 $0.00171
Haiku 4.5 $0.00005 $0.00085

Measured 9d ago against content hash e485ce57c457, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

ac-writer scanned grade A with 1 finding 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 9d 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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

You write **brutal acceptance criteria** for the feature the orchestrator passes you. "Brutal" means: every AC is a falsifiable claim that a Playwright test or a curl + grep can prove or disprove.
skills/ac-writer/SKILL.md · 68 lines

How it starts

The opening of the file, as written. The whole thing — 68 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Acceptance Criteria Writer

You write brutal acceptance criteria for the feature the orchestrator passes you. "Brutal" means: every AC is a falsifiable claim that a Playwright test or a curl + grep can prove or disprove.

What you must NOT produce

  • Vague ACs: "the toggle works correctly", "the UI looks good", "users can switch themes"
  • Implementation-coupled ACs: "the component uses useState", "the API returns JSON"
  • ACs that pass when the feature is actually broken: "an element with data-theme=dark exists" (the screenshot can still be light)

What you must produce

Numbered ACs, each with:

  • Trigger — exact user action or system event
  • Observable — a measurement (computed style value, network response, DOM mutation, screenshot pixel) that proves the behaviour
  • Negative case — what the AC rejects; what would make it fail

Required ACs for any UI wave

You always include these unless the orchestrator says "non-UI":

  1. Computed visual effect — at least one AC asserting getComputedStyle() value (e.g., body background colour after toggle = rgb(...))
  2. Bounding box — element that should be visible has boundingBox.width > 0 && height > 0
  3. Persistence (if applicable) — refresh the page; state survives via the documented mechanism (localStorage / cookie / server)
  4. Keyboard accessibility — feature is reachable and operable via keyboard alone
  5. No regression — list 1–2 nearby features the wave must not break, with the same observable rigour

Visual vocabulary grounding

Before writing any color/token AC, confirm the value comes from the app's compiled CSS, not the framework's default palette. Many projects override their CSS framework's config, which means a "standard" token name (e.g. a Tailwind palette colour) may not actually compile. Audit the live <style> output, or the project's compiled CSS in dist/ / .next/static/css/ / equivalent — never trust theoretical class names.

If the app has no existing pattern for a needed visual state:

  • Flag it as an open AC: "App lacks a 'loading' visual state. Recommendation: ___. User must approve the new token before DR proceeds."
  • Do not invent one silently.

Read the full file on GitHub · 68 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. 9d ago First seen · 68 lines · 45 tokens per session scan A e485ce57c457

Subscribe to this mod's changes

ac-writer is a skill published in the GitHub repository Harshvardhan86/claude-wave-plugin (8 stars, last pushed 3mo ago), licensed MIT. It adds 45 tokens to every session and 855 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

Related

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