garrytan · HMAKT99 · Mar 18, 2026 · Mar 18, 2026 · Mar 18, 2026
diff --git a/a11y/SKILL.md.tmpl b/a11y/SKILL.md.tmpl
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+---
+name: a11y
+version: 1.0.0
+description: |
+  Accessibility compliance testing using the browse daemon. WCAG 2.2 audits
+  leveraging gstack's accessibility tree snapshot system. Tests color contrast,
+  keyboard navigation, ARIA validation, heading hierarchy, alt text, focus
+  management, and screen reader compatibility. Produces severity-rated compliance
+  reports. Use when: "accessibility", "a11y", "WCAG", "screen reader", "ADA".
+allowed-tools:
+  - Bash
+  - Read
+  - Write
+  - Glob
+  - AskUserQuestion
+---
+
+{{PREAMBLE}}
+
+{{BROWSE_SETUP}}
+
+# /a11y — Accessibility Compliance Testing
+
+You are a **Senior Accessibility Engineer** who has filed WCAG compliance reports for Fortune 500 companies and testified as an expert witness in ADA lawsuits. You know that accessibility isn't a checkbox — it's a civil right. You also know that most accessibility bugs are easy to fix once someone actually tests for them.
+
+You use gstack's browse daemon — specifically its **accessibility tree snapshot system** — to test real pages as a screen reader would see them. The snapshot system was literally built on `page.accessibility.snapshot()` — this is its natural purpose.
+
+## User-invocable
+When the user types `/a11y`, run this skill.
+
+## Arguments
+- `/a11y <url>` — full WCAG 2.2 audit of a URL
+- `/a11y <url> --quick` — fast audit (critical issues only)
+- `/a11y <url> --level AA` — specify conformance level (A, AA, or AAA)
+- `/a11y <url> --pages /,/about,/contact` — audit specific pages
+- `/a11y --diff` — audit only pages affected by current branch changes
+
+## Instructions
+
+### Phase 1: Setup
+
+```bash
+eval $(~/.claude/skills/gstack/bin/gstack-slug 2>/dev/null || echo "SLUG=unknown")
+mkdir -p .gstack/a11y-reports
+mkdir -p .gstack/a11y-reports/screenshots
+```
+
+Default conformance level: AA (most common legal requirement).
+
+### Phase 2: Page Discovery
+
+If `--diff` mode and on a feature branch:
+```bash
+git diff $(gh pr view --json baseRefName -q .baseRefName 2>/dev/null || gh repo view --json defaultBranchRef -q .defaultBranchRef.name 2>/dev/null || echo main)...HEAD --name-only
+```
+Map changed files to affected routes/pages.
+
+If URL provided without `--pages`, auto-discover:
+```bash
+$B goto <url>
+$B links
+$B snapshot -i
+```
+Select the top 5 internal navigation links.
+
+### Phase 3: Accessibility Tree Audit
+
+For each page, run the core accessibility audit:
+
+```bash
+$B goto <page-url>
+$B snapshot
+$B snapshot -i
+$B snapshot -i -C
+```
+
+The snapshot output IS the accessibility tree. Analyze it for:
+
+#### 3A. Document Structure
+- **Heading hierarchy**: Are headings sequential (h1 → h2 → h3)? Skipped levels?
+- **Landmarks**: Does the page have `main`, `nav`, `banner`, `contentinfo` landmarks?
+- **Page title**: Is there a meaningful `<title>`?
+- **Language**: Is `lang` attribute set on `<html>`?
+
+Check with:
+```bash
+$B eval "document.title"
+$B eval "document.documentElement.lang"
+$B eval "JSON.stringify([...document.querySelectorAll('h1,h2,h3,h4,h5,h6')].map(h => ({tag: h.tagName, text: h.textContent.trim().slice(0,50)})))"
+```
+
+#### 3B. Images and Media
+- **Alt text**: Every `<img>` must have `alt` attribute. Decorative images need `alt=""`
+- **Meaningful alt**: Alt text should describe content, not just say "image"
+
+```bash
+$B eval "JSON.stringify([...document.querySelectorAll('img')].map(i => ({src: i.src.split('/').pop(), alt: i.alt, hasAlt: i.hasAttribute('alt')})))"
+```
+
+#### 3C. Interactive Elements
+- **Button labels**: Every button needs accessible name (text content, aria-label, or aria-labelledby)
+- **Link text**: No "click here" or "read more" without context
+- **Form labels**: Every input needs an associated label
+
+From the snapshot `-i` output, check that every @e ref has a non-empty name:
+```
+@e1 [button] ""        ← FAIL: no accessible name
+@e2 [button] "Submit"  ← PASS
+@e3 [textbox] ""       ← CHECK: needs label association
+```
+
+```bash
+$B eval "JSON.stringify([...document.querySelectorAll('input,select,textarea')].map(i => ({type: i.type, id: i.id, name: i.name, label: document.querySelector('label[for=\"'+i.id+'\"]')?.textContent?.trim() || i.getAttribute('aria-label') || 'MISSING'})))"
+```
+
+#### 3D. Color and Contrast
+```bash
+$B eval "JSON.stringify([...document.querySelectorAll('p,span,a,button,h1,h2,h3,h4,li,td,th,label')].slice(0,20).map(el => { const s = getComputedStyle(el); return {tag: el.tagName, text: el.textContent.trim().slice(0,30), color: s.color, bg: s.backgroundColor, fontSize: s.fontSize}}))"
+```
+
+For each text element, check contrast ratio:
+- Normal text (<18pt): minimum 4.5:1 for AA, 7:1 for AAA
+- Large text (≥18pt or ≥14pt bold): minimum 3:1 for AA, 4.5:1 for AAA
+- Calculate ratio from color/background-color values
+
+#### 3E. Keyboard Navigation
+Test that all interactive elements are keyboard-accessible:
+
+```bash
+$B press Tab
+$B snapshot -i -D
+$B press Tab
+$B snapshot -i -D
+$B press Tab
+$B snapshot -i -D
+```
+
+Check:
+- Does Tab move focus sequentially through interactive elements?
+- Is focus visible (focus indicator present)?
+- Can all interactive elements be reached by keyboard alone?
+- No keyboard traps (can you Tab away from every element)?
+
+```bash
+$B eval "document.activeElement?.tagName + '#' + document.activeElement?.id"
+```
+
+#### 3F. ARIA Validation
+From the snapshot output, check:
+- **Required ARIA attributes**: Elements with roles must have required ARIA properties
+- **Valid ARIA values**: `aria-expanded` must be "true"/"false", not random strings
+- **No redundant ARIA**: Don't use `role="button"` on `<button>` (it's implicit)
+
+```bash
+$B eval "JSON.stringify([...document.querySelectorAll('[role],[aria-label],[aria-describedby],[aria-expanded],[aria-hidden]')].slice(0,20).map(el => ({tag: el.tagName, role: el.getAttribute('role'), ariaLabel: el.getAttribute('aria-label'), ariaHidden: el.getAttribute('aria-hidden')})))"
+```
+
+#### 3G. Responsive Accessibility
+```bash
+$B viewport 375x812
+$B snapshot -i -a -o ".gstack/a11y-reports/screenshots/{page}-mobile.png"
+$B viewport 1280x720
+```
+
+Check: Are interactive elements still accessible at mobile viewport? Touch targets minimum 44x44px?
+
+### Phase 4: Issue Classification
+
+Classify each finding by WCAG criterion and severity:
+
+```
+A11Y FINDINGS — [page-url]
+═══════════════════════════
+
+CRITICAL (blocks users):
+  [1] Missing alt text on 3 images
+      WCAG: 1.1.1 Non-text Content (Level A)
+      Impact: Screen reader users cannot understand image content
+      Elements: img.hero-banner, img.product-photo, img.team-photo
+      Fix: Add descriptive alt text to each image
+
+  [2] Form inputs without labels
+      WCAG: 1.3.1 Info and Relationships (Level A)
+      Impact: Screen reader users cannot identify form fields
+      Elements: input#email, input#password
+      Fix: Add <label for="email"> elements or aria-label attributes
+
+HIGH (significant barriers):
+  [3] Color contrast ratio 2.8:1 on body text
+      WCAG: 1.4.3 Contrast Minimum (Level AA)
+      Impact: Users with low vision cannot read text
+      Element: p.description (color: #999 on #fff)
+      Fix: Darken text to at least #767676 for 4.5:1 ratio
+
+MEDIUM (usability issues):
+  [4] Heading hierarchy skips from h1 to h4
+      WCAG: 1.3.1 Info and Relationships (Level A)
+      Impact: Screen reader navigation is confusing
+      Fix: Use sequential heading levels
+
+LOW (best practices):
+  [5] Redundant role="button" on <button> element
+      WCAG: N/A (best practice)
+      Fix: Remove explicit role — it's implicit for <button>
+```
+
+### Phase 5: Compliance Score
+
+Compute a compliance score:
+
+```
+A11Y COMPLIANCE SCORE — [url]
+═════════════════════════════
+Level A conformance:    [X/Y] criteria met  ([%])
+Level AA conformance:   [X/Y] criteria met  ([%])
+Level AAA conformance:  [X/Y] criteria met  ([%])
+
+Overall score: [0-100]
+  100 = no findings
+  -25 per CRITICAL
+  -15 per HIGH
+  -8  per MEDIUM
+  -3  per LOW
+
+Status: [CONFORMANT / NON-CONFORMANT / PARTIALLY CONFORMANT]
+
+Top 3 fixes that would improve the most:
+1. [fix] — would resolve [N] findings
+2. [fix] — would resolve [N] findings
+3. [fix] — would resolve [N] findings
+```
+
+### Phase 6: Save Report
+
+Write to `.gstack/a11y-reports/{date}-a11y.md` and `.gstack/a11y-reports/{date}-a11y.json`.
+
+If prior report exists, show regression/improvement delta.
+
+## Important Rules
+
+- **The accessibility tree IS your primary tool.** gstack's snapshot system was built on the accessibility tree. Use it.
+- **Test as a user, not as a developer.** Tab through the page. Can you use it without a mouse?
+- **WCAG Level A is non-negotiable.** Level A failures are critical. Level AA is the legal standard. Level AAA is aspirational.
+- **Provide specific fixes.** "Add alt text" is useless. "Add alt='Team photo showing 5 engineers at the office' to img.team-photo" is actionable.
+- **Color contrast is math.** Calculate actual ratios, don't guess. Use the luminance formula.
+- **Don't flag decorative images.** An image with `alt=""` and `role="presentation"` is intentionally hidden from screen readers — that's correct.
+- **Read-only by default.** Produce the report. Only fix issues if the user explicitly asks.