web-accessibility

A guide for making websites and web apps usable by people with disabilities, based on WCAG 2.2 AA accessibility requirements. It covers page structure, keyboard use, focus, forms, contrast, touch targets, and accessibility testing.

In plain words
What is it for?
Use it when building or reviewing web pages, web apps, forms, navigation, dialogs, touch interfaces, or screen-reader behavior.
Why use it?
It helps catch barriers that can prevent people from navigating, reading, or completing tasks in a web interface. It also makes accessibility checks part of normal web development.

Skill for Claude CodeCodex

Part of the ai-instruct plugin — 5 skills shipped together

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/ziniman/ai-instruct/web-accessibility
Any agent
npx skills add ziniman/ai-instruct --skill web-accessibility
Clone the repo
git clone --depth 1 https://github.com/ziniman/ai-instruct

Made for: Claude Code, Codex.

Or install ai-instruct, the plugin that ships this one along with the rest of its 5 skills.

Per session 145 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 8,521 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. 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 $0.00145 $0.08521
Opus 5 $0.00072 $0.04261
Sonnet 5 $0.00029 $0.01704
Haiku 4.5 $0.00015 $0.00852

Measured 3d ago against content hash 8e4f97d6f119, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

web-accessibility 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 3d 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.

skills/web-accessibility/SKILL.md · 838 lines

How it starts

The opening of the file, as written. The whole thing — 838 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Web Accessibility Guide

Applies to: Any website or web app | Updated: March 2026

A practical reference for building accessible websites - covering WCAG 2.2 criteria, semantic HTML, ARIA, forms, touch, and testing.


Section 0: Before You Start

Answer these questions before generating accessibility code. Each answer changes which sections apply.

Q: Where are your users? Default: worldwide - EU/UK requirements (EAA, PSBAR) will be flagged as applicable throughout this guide. Options: US only | Europe/EU | UK | Worldwide

Q: What kind of product is this? Default: company/marketing website Options: Company/marketing website | Online shop/e-commerce | Web app/SaaS | Media/video site | Document tool

Q: Will people use this on mobile phones or tablets as well as desktop? Default: yes - touch target sizing and pointer accessibility sections apply.

Q: Are you building with a component library? Default: none Options: Radix UI | shadcn/ui | MUI | Chakra UI | Other | None - if a library is detected in package.json, note which accessibility features it handles natively so you don't duplicate them.

Q: Do you need to comply with a specific standard for legal or contract reasons? Default: WCAG 2.2 AA - current best-practice baseline. Options: WCAG 2.1 AA | WCAG 2.2 AA | Section 508 | EN 301 549 | Not sure

AI assistant: Use these answers to prioritize. For EU products: apply EAA compliance notes. For mobile: apply touch target and pointer sections. If a known accessible component library is detected, note which patterns it handles so you don't duplicate effort.


Contents

  1. Legal & Compliance
  2. WCAG Standards Overview
  3. WCAG 2.2 - What's New
  4. Semantic HTML
  5. Keyboard Navigation
  6. ARIA
  7. Images & Media
  8. Forms
  9. Touch & Pointer
  10. Color & Contrast
  11. Focus Management
  12. Motion & Animation
  13. Testing
  14. Anti-Patterns to Flag
  15. Checklist by Product Type

Read the full file on GitHub · 838 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. 3d ago First seen · 838 lines · 145 tokens per session scan A 8e4f97d6f119

Subscribe to this mod's changes

web-accessibility is a skill published in the GitHub repository ziniman/ai-instruct (28 stars, last pushed 3mo ago), licensed Apache-2.0. It adds 145 tokens to every session and 8,521 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 2026-08-30.

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