a11y-validate

name	a11y-validate
description	Accessibility validator: WCAG 2.1 AA, EN 301 549, EAA. Triggers: a11y, accessibility, WCAG, EAA, ARIA, contrast, keyboard, screen reader.
user-invocable	true
effort	medium
disable-model-invocation	true
context	fork
agent	frontend-specialist
argument-hint	[path] [--scope full|keyboard|contrast|forms|media|aria|motion|mobile|docs] [--standard wcag-2.1-aa|wcag-2.2-aa|en-301-549|eaa] [--severity high|warn|info] [--framework auto|react|next|nuxt|astro|gatsby|sveltekit|remix|angular|vue|react-native|flutter|static] [--output markdown|json]
allowed-tools	Read, Grep, Glob, Bash

/a11y-validate — Accessibility & EAA Compliance Scanner

$ARGUMENTS

Scan a codebase for accessibility issues using pattern-matching heuristics. Detects violations of WCAG 2.1 Level AA, EN 301 549 (the EU harmonized accessibility standard), and the European Accessibility Act (Directive (EU) 2019/882, "EAA", in force since 28 June 2025). Read-only — never modifies files.

Complements /seo-validate (which only covers SEO-a11y overlap shallowly). Use this skill when the concern is legal accessibility compliance, not search engine ranking.

Standards basis:

• WCAG 2.1 Level A + AA — W3C Recommendation 2018 (updated 2023).
• WCAG 2.2 Level AA (opt-in via --standard wcag-2.2-aa) — adds 2.4.11 focus not obscured, 2.5.8 target size minimum, 3.2.6 consistent help, 3.3.7 redundant entry, 3.3.8 accessible authentication.
• EN 301 549 v3.2.1 — EU harmonized standard; aligned with WCAG 2.1 AA plus additional chapters for mobile, hardware, ICT procurement, authoring tools, and functional-performance statements.
• EAA / Directive (EU) 2019/882 — legal framework requiring EN 301 549 conformance for consumer-facing digital products and services in EU markets. Deadline: 28 June 2025. Requires accessibility statements per member-state templates.

Usage

/a11y-validate                                # Scan full project, auto-detect framework
/a11y-validate src/                           # Scan specific path
/a11y-validate --scope keyboard               # Only keyboard + focus checks
/a11y-validate --scope media                  # Only captions/transcripts/autoplay
/a11y-validate --scope docs                   # Only EAA accessibility-statement check
/a11y-validate --scope mobile                 # Only React Native + Flutter patterns
/a11y-validate --standard eaa                 # Activate EAA documentation category
/a11y-validate --standard wcag-2.2-aa         # Add WCAG 2.2 criteria
/a11y-validate --severity high                # Filter to HIGH findings
/a11y-validate --framework react-native       # Force framework
/a11y-validate --output json                  # Structured JSON for CI integration

Scopes:

• full (default) — all 8 categories
• keyboard — Category 3 only
• contrast — Category 4 only
• forms — Category 5 only
• media — Category 6 only
• aria — Category 7 only
• motion — Category 8 motion subsection
• mobile — Category 8 mobile subsection (React Native / Flutter)
• docs — Category 8 EAA documentation subsection (fast "are we legally exposed?" scan)

Standards:

• wcag-2.1-aa (default) — 50 Level A + AA success criteria.
• wcag-2.2-aa — adds 2.4.11, 2.5.8, 3.2.6, 3.3.7, 3.3.8.
• en-301-549 — wcag-2.1-aa + mobile chapter + functional-performance statements.
• eaa — en-301-549 + accessibility-statement documentation requirement (activates Category 8 docs).

Severity filtering: --severity high shows only HIGH, --severity warn shows HIGH+WARN, --severity info shows all. Default: all.

What This Command Does

1. Detect framework from package.json, pubspec.yaml, and entry HTML.
2. Scan the codebase using Grep / Glob / Read against framework-aware patterns per category in scope.
3. Interpret findings with specific fixes tied to the detected framework.
4. Report findings sorted by severity with WCAG / EN 301 549 citations.

Steps

Step 1: Detect Framework

Run detection before scanning. Same logic as /seo-validate plus mobile entries:

Deps / files contain	Framework	Notes
next	next	App Router uses metadata export
nuxt	nuxt	useHead() / definePageMeta
astro	astro	islands model; client:only affects a11y
gatsby	gatsby	Head API + react-helmet
@sveltejs/kit	sveltekit	<svelte:head>
@remix-run/*	remix	MetaFunction
@angular/core	angular	CDK a11y module expected
vue (no nuxt)	vue	a11y plugins optional
react + vite (no next/remix)	react-spa	—
react-scripts	cra	—
react-native	react-native	mobile — AccessibilityInfo API
pubspec.yaml with Flutter SDK	flutter	mobile — Semantics() widget
no framework deps	static	raw HTML

Also detect a11y libraries: @react-aria/*, @reach/*, @angular/cdk/a11y, vue-a11y, svelte-a11y, react-axe, axe-core. Their presence is INFO.

Step 2: Run Category Scans

For each category in --scope, apply the pattern set below using Grep + Read. Patterns adapt to the detected framework.

Step 3: Interpret and Enrich

For each finding:

1. Read the flagged file/lines to confirm the match.
2. Add a framework-specific fix (e.g., "use @react-aria/button" vs "add aria-label").
3. Mark confidence — definitive for regex matches, heuristic for co-occurrence / absence / target-size estimation.
4. Skip false positives when context shows the concern is addressed (e.g., aria-label set via intl translation key).

Step 4: Report

Present findings sorted by severity (HIGH → WARN → INFO), then file path.

---

Scanner Reference

Category 1: Semantic Structure & Landmarks

WCAG 1.3.1 (Info and Relationships), 2.4.1 (Bypass Blocks), 2.4.6 (Headings and Labels), 3.1.1 (Language of Page), 3.1.2 (Language of Parts).

Pattern	Severity	Confidence	Description
<html> missing lang attribute	HIGH	definitive	WCAG 3.1.1
Mixed-language content without <span lang="..."> wrapper (heuristic: non-Latin characters in otherwise-Latin content)	WARN	heuristic	WCAG 3.1.2
Page/route component with >1 <h1>	WARN	heuristic	WCAG 1.3.1
Heading level skip (h1 → h3 without h2)	WARN	heuristic	WCAG 1.3.1
No landmark roles / semantic elements (<main>, <nav>, <header>, <footer>)	WARN	heuristic	WCAG 1.3.1, 2.4.1
role="presentation" / role="none" on semantic element	WARN	definitive	Strips meaning; misuse of ARIA
Multiple <main> per page	HIGH	definitive	WCAG 1.3.1 — only one <main> allowed

Category 2: Text Alternatives & Non-Text Content

WCAG 1.1.1 (Non-text Content).

Pattern	Severity	Confidence	Description
<img> without alt attribute	HIGH	definitive	WCAG 1.1.1 — required even if empty
<img alt=""> on informational image (heuristic: image inside <article>, <figure>, or with adjacent caption)	WARN	heuristic	Empty alt only for decorative
<img alt="image"> / <img alt="photo"> / <img alt="picture"> (redundant/meaningless)	WARN	definitive	Alt should describe content
<svg> without <title> + role="img" + aria-label, used in interactive context	WARN	heuristic	Inline SVG needs alternative
Icon font (<i class="fa-...">, <span class="material-icons">) without aria-label or text alternative	WARN	definitive	WCAG 1.1.1
<img> used for text content (heuristic: alt contains a full sentence like "Click here to...")	WARN	heuristic	WCAG 1.4.5 Images of Text
Complex image (<img> with src matching `chart	graph	diagram	infographic) without long description (aria-describedbyorlongdesc` or linked description)

Category 3: Keyboard & Focus

WCAG 2.1.1 (Keyboard), 2.1.2 (No Keyboard Trap), 2.4.3 (Focus Order), 2.4.7 (Focus Visible).

Pattern	Severity	Confidence	Description
tabindex value >0 (positive)	HIGH	definitive	WCAG 2.4.3 — breaks natural tab order
tabindex="-1" on natively interactive element (<button>, <a href>, <input>, etc.)	WARN	definitive	Removes from tab order
outline: none or outline: 0 on focusable selector without :focus-visible replacement	HIGH	definitive	WCAG 2.4.7
onClick / onKeyDown handler on <div> / <span> without role="button" + tabindex="0" + keydown handler for Enter/Space	HIGH	heuristic	WCAG 2.1.1 — not keyboard-accessible
No skip link (<a href="#main">, <a href="#content">) on page with navigation	WARN	heuristic	WCAG 2.4.1 Bypass Blocks
Potential keyboard trap: event.preventDefault() / event.stopPropagation() in keydown handler on modal/dialog without Escape handling	WARN	heuristic	WCAG 2.1.2
Custom dropdown / combobox without aria-expanded + aria-haspopup + keyboard handlers	WARN	heuristic	WAI-ARIA Authoring Practices
autofocus on page load on non-critical input (distracts keyboard users, moves focus unexpectedly)	WARN	definitive	Confuses assistive tech
contenteditable="true" without aria-label / aria-labelledby	WARN	definitive	WCAG 4.1.2

Category 4: Color, Contrast & Visual Cues

WCAG 1.4.1 (Use of Color), 1.4.3 (Contrast Minimum), 1.4.11 (Non-text Contrast).

Static analysis limitation: actual contrast ratios depend on the CSS cascade, custom properties, theme switching, and background images. The skill flags patterns where contrast is AT RISK; pair with runtime tools (axe-core, Lighthouse) for definitive measurement.

Pattern	Severity	Confidence	Description
Hardcoded foreground+background color pairs in CSS where computed contrast is <4.5:1 (normal) or <3:1 (large text)	WARN	heuristic	WCAG 1.4.3 — verify at runtime
Link inside body text without underline/border AND only color distinguishing it	WARN	heuristic	WCAG 1.4.1 — color-only signalling
Error/required field indicated only by red color (no icon, text, or shape)	WARN	heuristic	WCAG 1.4.1
Required form field marked only with * character without aria-required="true" + text explanation	WARN	definitive	WCAG 1.4.1 + 3.3.2
CSS uses color: red/color: green as sole signal (success vs error)	WARN	heuristic	WCAG 1.4.1
Focus indicator with <3:1 contrast against background (heuristic from color values)	WARN	heuristic	WCAG 1.4.11
Button/input border color with <3:1 contrast against adjacent color	WARN	heuristic	WCAG 1.4.11
CSS text-shadow/opacity on body text reducing effective contrast	INFO	heuristic	May affect 1.4.3

Category 5: Forms, Labels & Errors

WCAG 1.3.5 (Identify Input Purpose), 3.3.1 (Error Identification), 3.3.2 (Labels or Instructions), 3.3.3 (Error Suggestion), 4.1.2 (Name, Role, Value).

Pattern	Severity	Confidence	Description
<input> / <select> / <textarea> without <label for="..."> AND without aria-label / aria-labelledby	HIGH	heuristic	WCAG 3.3.2, 4.1.2
<label> without for attribute (implicit association only works if input is a child)	WARN	definitive	WCAG 3.3.2
<input type="email"/tel/name/password/address"> without autocomplete attribute	WARN	definitive	WCAG 1.3.5
Missing autocomplete="one-time-code" on OTP input with inputmode="numeric"	INFO	definitive	Improves user experience
Radio / checkbox group without <fieldset> + <legend>	WARN	heuristic	WCAG 1.3.1
Error messages displayed visually but not linked via aria-describedby to the input	WARN	heuristic	WCAG 3.3.1
required attribute without accompanying aria-required="true" (belt-and-suspenders for assistive tech consistency)	INFO	definitive	WCAG 4.1.2 (modern SR handle required but legacy may not)
Error uses role="alert" without being updated dynamically (static alert on page load)	INFO	heuristic	WCAG 4.1.3
Placeholder used as label (no visible label, only placeholder)	WARN	heuristic	WCAG 3.3.2 — placeholder disappears on focus
<input type="email"> without inputmode="email" (mobile UX)	INFO	definitive	EN 301 549 mobile

Category 6: Media (Audio, Video, Embeds)

WCAG 1.2.1–1.2.5 (Captions, audio description, sign language), 1.4.2 (Audio Control).

EAA is specifically strict about media — video without captions is a common legal-risk finding.

Pattern	Severity	Confidence	Description
<video> without <track kind="captions"> child (or <track kind="subtitles"> for foreign-language)	HIGH	definitive	WCAG 1.2.2 — EAA legal risk
<video> without transcript link or <track kind="descriptions">	WARN	heuristic	WCAG 1.2.3 / 1.2.5
<audio> without transcript link or <track kind="captions">	HIGH	definitive	WCAG 1.2.1
<video autoplay> without muted	HIGH	definitive	WCAG 1.4.2 — auto-playing audio
<video autoplay loop> running >5 seconds without pause control	WARN	heuristic	WCAG 1.4.2, 2.2.2
YouTube/Vimeo embed URL without cc_load_policy=1 or equivalent CC parameter	INFO	definitive	Platform-dependent captioning
YouTube embed via <iframe src="https://www.youtube.com/embed/..."> without accessibility enhancements	INFO	definitive	Note: platform controls most a11y
Live media without real-time caption indication	WARN	heuristic	WCAG 1.2.4
Background video (hero section) without pause button in DOM	WARN	heuristic	WCAG 2.2.2

Category 7: ARIA, Live Regions & Dynamic Content

WCAG 4.1.2 (Name, Role, Value), 4.1.3 (Status Messages).

Pattern	Severity	Confidence	Description
aria-hidden="true" on focusable element	HIGH	definitive	Creates orphaned focus — serious a11y bug
role="button" on native <button> (redundant ARIA)	WARN	definitive	ARIA Authoring: avoid redundant roles
role="link" on <a href> / role="heading" on <h1–h6> (redundant ARIA)	WARN	definitive	Same
Conflicting roles (<button role="link">, <a role="button">)	WARN	definitive	WAI-ARIA — wrong role
Custom toggle (disclosure, menu, accordion) without aria-expanded + aria-controls	WARN	heuristic	WAI-ARIA
aria-labelledby referencing non-existent ID	HIGH	heuristic	Broken reference
aria-describedby referencing non-existent ID	HIGH	heuristic	Broken reference
aria-live region without role="status" / role="alert" AND async updates in component (heuristic)	WARN	heuristic	WCAG 4.1.3
Toast/notification component without role="status" or role="alert"	WARN	heuristic	WCAG 4.1.3
Modal / dialog without role="dialog" + aria-modal="true" + focus trap	WARN	heuristic	WAI-ARIA Authoring Practices
Tabs without proper roles (role="tablist" + role="tab" + role="tabpanel")	WARN	heuristic	WAI-ARIA Authoring Practices

Category 8: Motion, Target Size, Mobile & EAA Docs

8a. Motion & Animation

WCAG 2.2.2 (Pause, Stop, Hide), 2.3.3 (Animation from Interactions — AAA but EAA-recommended).

Pattern	Severity	Confidence	Description
CSS animation / transition / transform without matching @media (prefers-reduced-motion: reduce) override	WARN	heuristic	WCAG 2.3.3
JS animation library (GSAP, framer-motion, anime.js) without matchMedia('(prefers-reduced-motion: reduce)') check	WARN	heuristic	WCAG 2.3.3
Parallax scrolling without opt-out	WARN	heuristic	WCAG 2.3.3
Infinite animation (CSS animation: name infinite) on content element without pause control	WARN	heuristic	WCAG 2.2.2
<marquee> / <blink> (deprecated)	HIGH	definitive	WCAG 2.2.2

8b. Target Size (WCAG 2.2 Minimum AA 2.5.8 + EN 301 549)

Pattern	Severity	Confidence	Description
Interactive target with declared size <24×24 px (heuristic from CSS: width/height/padding on buttons/links/inputs)	WARN	heuristic	WCAG 2.2 2.5.8 / EN 301 549
Touch-target spacing <8 px between adjacent interactive elements	INFO	heuristic	Best practice

8c. Viewport & Zoom

Pattern	Severity	Confidence	Description
<meta name="viewport"> containing user-scalable=no / user-scalable=0	HIGH	definitive	WCAG 1.4.4 — blocks zoom
<meta name="viewport"> with maximum-scale=1 / maximum-scale=1.0	HIGH	definitive	WCAG 1.4.4
Content rendered via <img> for text (text-as-image)	WARN	heuristic	WCAG 1.4.5

8d. Mobile (React Native + Flutter)

EN 301 549 mobile chapter. Critical for EAA scope since consumer apps are in-scope.

Pattern	Severity	Confidence	Description
React Native: <TouchableOpacity> / <TouchableHighlight> / <Pressable> without accessibilityLabel	HIGH	definitive	EN 301 549 mobile
React Native: <Image> without accessibilityLabel or accessible={false}	WARN	heuristic	EN 301 549
React Native: Missing accessibilityRole on custom components that behave as buttons/links	WARN	heuristic	EN 301 549
React Native: Alert.alert for error flow without AccessibilityInfo.announceForAccessibility fallback	INFO	heuristic	—
Flutter: Interactive widget (GestureDetector, InkWell, TextButton, IconButton) without Semantics() wrapper or semanticLabel parameter	HIGH	definitive	EN 301 549 mobile
Flutter: Image() / Image.asset() / Image.network() without semanticLabel (or excludeFromSemantics: true for decorative)	WARN	definitive	EN 301 549
Flutter: Missing ExcludeSemantics / MergeSemantics where child semantics conflict	INFO	heuristic	Semantics tree cleanup

8e. EAA Accessibility Documentation

Activated by --standard eaa. EAA Article 14 + member-state transpositions require consumer-facing services to publish an accessibility statement. Missing statement = HIGH legal finding.

Pattern	Severity	Confidence	Description
No route at any of: /accessibility, /accessibility-statement, /a11y, /dostepnosc (PL), /barrierefreiheit (DE), /declaration-accessibilite (FR), /declaración-accesibilidad (ES), /dichiarazione-accessibilita (IT), /toegankelijkheidsverklaring (NL)	HIGH	heuristic	EAA Article 14
Footer / sitemap lacks link to accessibility statement	HIGH	heuristic	EAA visibility requirement
Accessibility statement present but missing required elements: (a) conformance level (WCAG/EN 301 549), (b) list of non-conformant content, (c) feedback mechanism, (d) enforcement procedure link	WARN	heuristic	Member-state template requirement
No contact mechanism (email / form) for accessibility feedback referenced in statement	WARN	heuristic	EAA Article 14
robots.txt disallows /accessibility* path (accidentally blocks statement from crawlers + assistive tech)	WARN	definitive	Discoverability

See: reference/eaa-compliance.md for directive text, member-state deadlines, statement templates.

---

Output Format

## Accessibility Validation Report

### Summary
| Metric | Value |
|--------|-------|
| Standard | wcag-2.1-aa / wcag-2.2-aa / en-301-549 / eaa |
| Scope | full / keyboard / contrast / forms / media / aria / motion / mobile / docs |
| Framework detected | next / nuxt / astro / ... / react-native / flutter / static |
| Files scanned | N |
| Public routes scanned | N |
| Accessibility statement | found / not-found |
| Findings: HIGH | N |
| Findings: WARN | N |
| Findings: INFO | N |

### Findings

#### [HIGH] src/components/VideoPlayer.tsx:42
Category: Media
Confidence: definitive
Pattern: `<video>` without `<track kind="captions">`
WCAG: 1.2.2 (Captions — Prerecorded, Level AA)
EAA: Article 4 (product/service accessibility requirements)
Fix: Add `<track kind="captions" src="/captions/en.vtt" srclang="en" label="English" default>`. If captions are unavailable, provide a transcript link.
See: reference/wcag-2-1-aa.md#guideline-12-time-based-media

#### [HIGH] public/index.html:8
Category: Viewport & Zoom
Confidence: definitive
Pattern: `<meta name="viewport" content="..., user-scalable=no">`
WCAG: 1.4.4 (Resize Text, Level AA)
Fix: Remove `user-scalable=no` and `maximum-scale=1` from the viewport meta — users must be able to zoom to 200%.
See: reference/wcag-2-1-aa.md#144-resize-text

#### [HIGH] src/routes.tsx:15
Category: EAA Accessibility Documentation
Confidence: heuristic
Pattern: No `/accessibility` / `/accessibility-statement` route detected; footer contains no a11y link
Standard: EAA Article 14 (mandatory accessibility statement)
Fix: Publish an accessibility statement conforming to your member-state template. Link it from the footer of every public page. See reference/eaa-compliance.md for template structure.

Confidence values:

• definitive — regex match against a known-bad pattern.
• heuristic — co-occurrence, absence, ordering, or derived inference (target size from CSS, contrast from hardcoded colors, ATF detection).

Exit codes (when --output json):

• 0 — no HIGH findings.
• 1 — one or more HIGH findings.

Out of Scope (Static Analysis Cannot Detect)

The skill explicitly does NOT verify the following — pair with runtime tools:

• Actual contrast ratios under runtime CSS cascade, theme switching, custom properties (use axe-core, Lighthouse, or manual tooling).
• Zoom / reflow behavior at 200% / 400% (WCAG 1.4.10, 1.4.4) — requires rendering.
• Screen reader announcement order and quality (NVDA, JAWS, VoiceOver, TalkBack).
• Cognitive accessibility (WCAG 3.x is mostly process/content-driven, not pattern-matchable).
• Actual keyboard trap behavior — requires interaction.
• Pronunciation / lang switches at runtime.
• Real-time caption accuracy.
• Usability / comprehension — requires user studies.

For these, use: axe-core, pa11y, Lighthouse accessibility audit, manual assistive-tech testing, and user research with disabled participants.

Rules

• Read-only: Never modify any files.
• Framework-aware: Detect framework first; apply correct pattern set.
• Standards citation: Every HIGH/WARN finding cites a WCAG success criterion (e.g., "1.3.1") or EN 301 549 clause.
• Skip non-source files: Binary files, lock files, vendored directories (node_modules/, vendor/, dist/, build/, .next/, .nuxt/, .svelte-kit/, ios/Pods/, android/build/, .dart_tool/).
• No false confidence: Label heuristic findings clearly. Color contrast and target size are ALWAYS heuristic in static analysis.
• EAA docs category is LEGAL risk: Missing accessibility statement when --standard eaa is selected is HIGH — this is a regulatory finding, not a code-quality suggestion.
• No auto-fix: A11y fixes often require design/content decisions that exceed pattern matching.
• Don't flag missing ARIA when native semantics suffice: Prefer native HTML elements; flag redundant ARIA, not absence when the native element is already there.

Reference Documents

• reference/wcag-2-1-aa.md — All 50 Level A + AA success criteria with detection status (statically detectable vs runtime-only).
• reference/wcag-2-2-aa.md — 9 new WCAG 2.2 success criteria (2.4.11, 2.4.12, 2.4.13, 2.5.7, 2.5.8, 3.2.6, 3.3.7, 3.3.8, 3.3.9) with failure patterns, grep patterns, and framework notes.
• reference/eaa-compliance.md — EU Directive 2019/882 articles, EN 301 549 v3.2.1 mapping, 28 June 2025 timeline, member-state transposition deltas, accessibility-statement templates.
• reference/aria-patterns.md — ARIA 1.2 Authoring Practices: landmarks, roles, states/properties, common anti-patterns, framework-specific helpers (@react-aria, @angular/cdk/a11y).
• reference/mobile-eaa.md — EN 301 549 mobile chapter + React Native AccessibilityInfo / Flutter Semantics() patterns.

Related Skills

• /seo-validate — SEO scanner; Category 9 covers a11y-for-SEO overlap only. For deep a11y compliance use /a11y-validate.
• /cve-scan — dependency vulnerability scanner.
• /hipaa-validate — HIPAA compliance scanner (similar pattern).