accessibility

accessibility is a skill for Claude Code, Codex from open-gsd/gsd-pi. It costs 51 tokens per session (3,287 once invoked), scanned C, original, MIT.

A web-accessibility audit and improvement skill based on WCAG 2.1, a standard for making websites usable by people with disabilities and with assistive technology.

In plain words
What is it for?
Use it to review or improve alternative text, keyboard navigation, screen-reader support, and the site's conformance level.
Why use it?
It helps find barriers such as missing image descriptions, poor keyboard access, or content that users cannot perceive or understand.

Skill for Claude CodeCodex

About the project

GSD Pi is a command-line coding agent and project workflow system that plans, implements, verifies, and tracks software work through milestones, tasks, Git worktrees, and stored project notes. It is for developers who want structured, longer-running agent sessions using different model providers. The catalogue entries extend GSD Pi with skills and agents.

open-gsd/gsd-pi · 1,198 stars · on GitHub

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.

agentmods
npx agentmods add skills/open-gsd/gsd-pi/accessibility
Any agent
npx skills add open-gsd/gsd-pi --skill accessibility
Clone the repo
git clone --depth 1 https://github.com/open-gsd/gsd-pi

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 accessibility

README.md
[![agentmods](https://agentmods.dev/badge/skills/open-gsd/gsd-pi/accessibility.svg)](https://agentmods.dev/skills/open-gsd/gsd-pi/accessibility)
Your own site
<a href="https://agentmods.dev/skills/open-gsd/gsd-pi/accessibility"><img src="https://agentmods.dev/badge/skills/open-gsd/gsd-pi/accessibility.svg" alt="Measured on agentmods" height="20"></a>
Per session 51 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,287 The whole file, excluding the scripts and references it only reads on demand.
Security scan C 1 finding. Scan, not verified.
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 $0.00051 $0.03287
Opus 5 $0.00026 $0.01643
Sonnet 5 $0.00010 $0.00657
Haiku 4.5 $0.00005 $0.00329

Measured 5d ago against content hash df14b3a23e79, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade C, and why

accessibility scanned grade C 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 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.

Hidden instructionshighPrompt injection

Directives inside HTML comments, invisible characters or bidirectional overrides are read by the model and not by the person reviewing the file.

<!-- ✅ With instructions -->
src/resources/skills/accessibility/SKILL.md · 523 lines

How it starts

The opening of the file, as written. The whole thing — 523 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Accessibility (a11y)

Comprehensive accessibility guidelines based on WCAG 2.1 and Lighthouse accessibility audits. Goal: make content usable by everyone, including people with disabilities.

WCAG Principles: POUR

Principle Description
Perceivable Content can be perceived through different senses
Operable Interface can be operated by all users
Understandable Content and interface are understandable
Robust Content works with assistive technologies

Conformance levels

Level Requirement Target
A Minimum accessibility Must pass
AA Standard compliance Should pass (legal requirement in many jurisdictions)
AAA Enhanced accessibility Nice to have

Perceivable

Text alternatives (1.1)

Images require alt text:

<!-- ❌ Missing alt -->
<img src="chart.png">

<!-- ✅ Descriptive alt -->
<img src="chart.png" alt="Bar chart showing 40% increase in Q3 sales">

<!-- ✅ Decorative image (empty alt) -->
<img src="decorative-border.png" alt="" role="presentation">

<!-- ✅ Complex image with longer description -->
<figure>
  <img src="infographic.png" alt="2024 market trends infographic" 
       aria-describedby="infographic-desc">
  <figcaption id="infographic-desc">
    <!-- Detailed description -->
  </figcaption>
</figure>

Icon buttons need accessible names:

<!-- ❌ No accessible name -->
<button><svg><!-- menu icon --></svg></button>

<!-- ✅ Using aria-label -->
<button aria-label="Open menu">
  <svg aria-hidden="true"><!-- menu icon --></svg>
</button>

<!-- ✅ Using visually hidden text -->
<button>
  <svg aria-hidden="true"><!-- menu icon --></svg>
  <span class="visually-hidden">Open menu</span>
</button>

Visually hidden class:

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

Read the full file on GitHub · 523 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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 First seen · 523 lines · 51 tokens per session scan C df14b3a23e79

Subscribe to this mod's changes

accessibility is a skill published in the GitHub repository open-gsd/gsd-pi (1,198 stars, last pushed today), licensed MIT. It adds 51 tokens to every session and 3,287 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it C with 1 finding (hidden instructions). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.