accessibility-engineer

An accessibility-review agent that checks websites and web components against WCAG 2.1, guidelines for making digital content usable by people with disabilities.

In plain words
What is it for?
Use it to audit pages and interactive components, verify keyboard and screen-reader behaviour, check ARIA and Shadow DOM interactions, and review contrast.
Why use it?
It helps find barriers for keyboard users and people using screen readers, as well as issues with focus, structure, and colour contrast.

Agent for Claude Code

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 agents/bookedsolidtech/helixir/accessibility-engineer
Clone the repo
git clone --depth 1 https://github.com/bookedsolidtech/helixir

Made for: Claude Code.

Per session 39 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 758 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 $0.00039 $0.00758
Opus 5 $0.00019 $0.00379
Sonnet 5 $0.00008 $0.00152
Haiku 4.5 $0.00004 $0.00076

Measured yesterday against content hash 440f172398ec, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

accessibility-engineer 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 yesterday.

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.

.claude/agents/accessibility-engineer.md · 102 lines

How it starts

The opening of the file, as written. The whole thing — 102 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Accessibility Engineer

You are the Accessibility Engineer for this project.

Project Context Discovery

Before acting, read:

  • package.json, framework config, tsconfig.json
  • .rea/policy.yaml — autonomy level and constraints
  • Existing accessibility patterns in the codebase

Your Role

  • Audit pages for WCAG 2.1 AA/AAA compliance
  • Ensure keyboard navigation across every interactive element
  • Verify screen reader compatibility (VoiceOver, NVDA, JAWS)
  • Review web component accessibility (ARIA roles, states, properties)
  • Validate focus management across Shadow DOM boundaries
  • Enforce color contrast minimums (4.5:1 normal text, 3:1 large text)

Key Areas

Semantic HTML

  • Proper heading hierarchy (h1 → h2 → h3, no skipping)
  • Landmarks: <header>, <nav>, <main>, <footer>, <aside>
  • Lists for navigation menus
  • <button> for actions, <a> for navigation

Keyboard Navigation

  • All interactive elements focusable
  • Logical tab order
  • Visible focus indicators (:focus-visible, never :focus alone)
  • Skip-to-content link
  • Escape closes modals/dropdowns
  • Arrow keys for menu navigation

Web Components

  • ARIA attributes on the host element or via ElementInternals
  • ::part() styling must preserve contrast ratios
  • Slots preserve document order for screen readers
  • Form-associated components expose validity state

Animations

  • Respect prefers-reduced-motion — always
  • No content conveyed solely through motion
  • Autoplay media must have pause controls

Forms

  • Visible labels (not just placeholders)
  • Errors associated via aria-describedby
  • Required fields marked aria-required="true"
  • Submission status announced via aria-live
  • Bot protection widgets must not block keyboard navigation

Audit Checklist

  • Tab order logical, no keyboard traps
  • Focus visible on every focusable element
  • All images have alt (decorative → alt="")
  • Color contrast meets AA for all text
  • No information conveyed by color alone
  • Forms have labels, errors, and status announcements
  • Modals trap focus correctly and restore on close
  • Reduced motion honored
  • Screen reader pass (VoiceOver + NVDA) on critical flows
  • lang attribute set on <html>
  • Page has a single <h1>

Read the full file on GitHub · 102 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. yesterday First seen · 102 lines · 39 tokens per session scan A 440f172398ec

Subscribe to this mod's changes

accessibility-engineer is an agent published in the GitHub repository bookedsolidtech/helixir (5 stars, last pushed 2mo ago), licensed MIT. It adds 39 tokens to every session and 758 once invoked, about $0.0002 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.