# A11y Audit

> Accessibility auditing: WCAG compliance checking, contrast ratios, ARIA labels, keyboard navigation, semantic HTML, screen reader compatibility.

- **Type:** Skill
- **Install:** `agentstack add skill-jansenanalytics-claudex-a11y-audit`
- **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior
- **Seller:** [JansenAnalytics](https://agentstack.voostack.com/s/jansenanalytics)
- **Installs:** 0
- **Category:** [Search](https://agentstack.voostack.com/c/search)
- **Latest version:** 0.1.0
- **License:** MIT
- **Upstream author:** [JansenAnalytics](https://github.com/JansenAnalytics)
- **Source:** https://github.com/JansenAnalytics/claudex/tree/main/skills/a11y-audit

## Install

```sh
agentstack add skill-jansenanalytics-claudex-a11y-audit
```

Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent.

## About

# a11y-audit

Accessibility auditing: WCAG compliance checking, contrast ratios, ARIA labels, keyboard navigation, semantic HTML, screen reader compatibility.

## Use When

- Auditing web pages for accessibility compliance
- Checking color contrast ratios against WCAG standards
- Verifying ARIA attributes and landmark usage
- Ensuring keyboard navigability
- Meeting WCAG 2.1 AA standards
- Reviewing HTML for semantic correctness and screen reader compatibility

## Scripts

### contrast-checker.py

Calculates WCAG contrast ratios between foreground and background colors. Pure Python, no dependencies.

**Single pair:**

```bash
python3 scripts/contrast-checker.py --fg "#333333" --bg "#ffffff"
```

**Batch mode** (reads JSON file with array of `{"fg": "#hex", "bg": "#hex", "label": "optional"}` objects):

```bash
python3 scripts/contrast-checker.py --batch colors.json
```

Output includes:

- Contrast ratio (e.g., 12.63:1)
- Pass/fail for AA normal text (≥4.5:1), AA large text (≥3:1)
- Pass/fail for AAA normal text (≥7:1), AAA large text (≥4.5:1)

### html-a11y-scan.py

Scans an HTML file for common accessibility issues. Uses Python's built-in `html.parser`.

```bash
python3 scripts/html-a11y-scan.py page.html
python3 scripts/html-a11y-scan.py page.html --format json
python3 scripts/html-a11y-scan.py page.html --format text
```

Checks for:

- Images without `alt` attributes (critical)
- Form inputs without labels or `aria-label` (critical)
- Missing `lang` attribute on `` (critical)
- Empty links or buttons (warning)
- Skipped heading levels (warning)
- Tables without `` headers (warning)
- Missing ARIA landmarks: `main`, `nav`, `banner`, `contentinfo` (info)

Output (JSON by default): array of issues with `severity`, `element`, `line`, `issue`, and `suggestion` fields.

### keyboard-nav-checklist.sh

Generates a Markdown checklist for manual keyboard navigation testing.

```bash
bash scripts/keyboard-nav-checklist.sh
bash scripts/keyboard-nav-checklist.sh --output checklist.md
```

Covers: focus management, tab order, focus indicators, modal behavior, keyboard traps, skip links, and more.

## References

- **wcag-quickref.md** — WCAG 2.1 AA requirements organized by principle (Perceivable, Operable, Understandable, Robust)
- **aria-patterns.md** — Common ARIA patterns with correct role/state/property usage for tabs, modals, accordions, menus, comboboxes

## Examples

### Quick contrast check

```bash
python3 scripts/contrast-checker.py --fg "#767676" --bg "#ffffff"
# Ratio: 4.54:1 — AA normal: PASS, AA large: PASS, AAA normal: FAIL, AAA large: PASS
```

### Full page audit

```bash
python3 scripts/html-a11y-scan.py mypage.html --format text
```

### Batch color audit for a design system

```json
[
  { "fg": "#333333", "bg": "#ffffff", "label": "body text" },
  { "fg": "#767676", "bg": "#ffffff", "label": "muted text" },
  { "fg": "#ffffff", "bg": "#0066cc", "label": "button text" }
]
```

```bash
python3 scripts/contrast-checker.py --batch design-colors.json
```

## Dependencies

- Python 3.6+ (standard library only)
- Bash (for keyboard checklist)

## Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [JansenAnalytics](https://github.com/JansenAnalytics)
- **Source:** [JansenAnalytics/claudex](https://github.com/JansenAnalytics/claudex)
- **License:** MIT

Install and usage instructions live in the source repository linked above.

## Pricing

- **Free** — Free

## Security capabilities

Automated source analysis of v0.1.0 — what this tool can access:

- **Network access:** no
- **Filesystem access:** no
- **Shell / process execution:** no
- **Environment & secrets:** no
- **Dynamic code execution:** no

*"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.*


## Versions

- **0.1.0** — security scan: passed — Imported from the upstream source.

## Links

- Listing page: https://agentstack.voostack.com/l/skill-jansenanalytics-claudex-a11y-audit
- Seller: https://agentstack.voostack.com/s/jansenanalytics
- Browse the marketplace: https://agentstack.voostack.com/browse

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