# LLM Agent Guide: ADA/WCAG Accessibility Testing with Cremote

## Purpose
This document provides LLM coding agents with concrete, actionable guidance for using Cremote's accessibility testing tools to conduct ADA/WCAG compliance audits.

## Quick Reference

### Tool Selection Matrix

| Testing Need | Primary Tool | Secondary Tool | WCAG Criteria |
|--------------|--------------|----------------|---------------|
| Comprehensive automated audit | `web_run_axe_cremotemcp` | - | ~57% of WCAG 2.1 AA |
| Color contrast issues | `web_contrast_check_cremotemcp` | `web_run_axe_cremotemcp` | 1.4.3, 1.4.6 |
| Keyboard accessibility | `web_keyboard_test_cremotemcp` | `web_run_axe_cremotemcp` | 2.1.1, 2.4.7 |
| Zoom/resize functionality | `web_zoom_test_cremotemcp` | - | 1.4.4 |
| Responsive design | `web_reflow_test_cremotemcp` | - | 1.4.10 |
| Visual documentation | `web_screenshot_cremotemcp` | - | Evidence capture |
| Custom JavaScript testing | `console_command_cremotemcp` | - | Advanced scenarios |

### Standard Testing Sequence

```
1. web_inject_axe_cremotemcp          # Inject axe-core library
2. web_run_axe_cremotemcp             # Run comprehensive automated tests
3. web_contrast_check_cremotemcp      # Detailed contrast analysis
4. web_keyboard_test_cremotemcp       # Keyboard navigation testing
5. web_zoom_test_cremotemcp           # Zoom functionality testing
6. web_reflow_test_cremotemcp         # Responsive design testing
```

## Tool Usage Patterns

### Pattern 1: Initial Audit

```json
// Step 1: Inject axe-core
{
  "tool": "web_inject_axe_cremotemcp",
  "arguments": {
    "timeout": 30
  }
}

// Step 2: Run comprehensive tests
{
  "tool": "web_run_axe_cremotemcp",
  "arguments": {
    "run_only": ["wcag2a", "wcag2aa", "wcag21aa"],
    "timeout": 30
  }
}

// Step 3: Analyze results and run specialized tests based on findings
```

### Pattern 2: Contrast-Specific Testing

```json
// For pages with known or suspected contrast issues
{
  "tool": "web_contrast_check_cremotemcp",
  "arguments": {
    "selector": "body",  // Test entire page
    "timeout": 10
  }
}

// For specific sections
{
  "tool": "web_contrast_check_cremotemcp",
  "arguments": {
    "selector": ".main-content",  // Test specific area
    "timeout": 10
  }
}
```

### Pattern 3: Keyboard Navigation Testing

```json
{
  "tool": "web_keyboard_test_cremotemcp",
  "arguments": {
    "timeout": 10
  }
}

// Analyze output for:
// - not_focusable: Elements that should be keyboard accessible but aren't
// - no_focus_indicator: Elements missing visible focus indicators
// - keyboard_trap: Elements that trap keyboard focus
```

### Pattern 4: Zoom and Responsive Testing

```json
// Test zoom levels (WCAG 1.4.4)
{
  "tool": "web_zoom_test_cremotemcp",
  "arguments": {
    "zoom_levels": [1.0, 2.0, 4.0],
    "timeout": 10
  }
}

// Test responsive breakpoints (WCAG 1.4.10)
{
  "tool": "web_reflow_test_cremotemcp",
  "arguments": {
    "widths": [320, 768, 1280],
    "timeout": 10
  }
}
```

### Pattern 5: Visual Documentation

```json
// Capture baseline
{
  "tool": "web_screenshot_cremotemcp",
  "arguments": {
    "output": "/tmp/baseline.png",
    "timeout": 5
  }
}

// Capture at 200% zoom
{
  "tool": "web_screenshot_cremotemcp",
  "arguments": {
    "output": "/tmp/zoom-200.png",
    "zoom_level": 2.0,
    "timeout": 5
  }
}

// Capture mobile view
{
  "tool": "web_screenshot_cremotemcp",
  "arguments": {
    "output": "/tmp/mobile-320.png",
    "width": 320,
    "height": 568,
    "timeout": 5
  }
}
```

## Interpreting Results

### Axe-Core Results

```json
{
  "violations": [
    {
      "id": "color-contrast",
      "impact": "serious",  // critical, serious, moderate, minor
      "description": "Elements must have sufficient color contrast",
      "nodes": [
        {
          "html": "<p class=\"text-gray\">Low contrast text</p>",
          "target": [".text-gray"],
          "failureSummary": "Fix any of the following:\n  Element has insufficient color contrast of 3.2:1 (foreground color: #808080, background color: #ffffff, font size: 12.0pt (16px), font weight: normal). Expected contrast ratio of 4.5:1"
        }
      ]
    }
  ],
  "passes": [...],      // Tests that passed
  "incomplete": [...],  // Tests requiring manual review
  "inapplicable": [...]  // Tests not applicable to this page
}
```

**Action Priority:**
1. **Critical/Serious violations** - Fix immediately
2. **Moderate violations** - Fix in current sprint
3. **Minor violations** - Fix when convenient
4. **Incomplete** - Manually review and test
5. **Passes** - Document for compliance

### Contrast Check Results

```
WCAG AA Violations:
  - p:nth-of-type(3): 3.2:1 (required: 4.5:1)
    Text: This text has insufficient contrast
    Colors: rgb(128, 128, 128) on rgb(255, 255, 255)
```

**Remediation:**
- Darken foreground color or lighten background
- Use contrast ratio calculator to find compliant colors
- Test with `web_contrast_check_cremotemcp` after fixes

### Keyboard Test Results

```
High Severity Issues:
  - not_focusable: Interactive element is not keyboard focusable
    Element: div[role="button"]
  - no_focus_indicator: Interactive element lacks visible focus indicator
    Element: button.submit-btn
```

**Remediation:**
- `not_focusable`: Add `tabindex="0"` or use semantic HTML (`<button>` instead of `<div>`)
- `no_focus_indicator`: Add CSS `:focus` styles with visible outline/border
- `keyboard_trap`: Review JavaScript event handlers and focus management

### Zoom Test Results

```
Zoom 400% ✗ FAIL:
  Horizontal Scroll: true
  Overflowing Elements: 3
  Text Readable: true
```

**Remediation:**
- Use responsive units (rem, em, %) instead of fixed pixels
- Implement CSS media queries for zoom levels
- Test with `max-width: 100%` on images and containers

### Reflow Test Results

```
320px Width ✗ FAIL:
  Horizontal Scroll: true
  Responsive Layout: false
  Overflowing Elements: 5
```

**Remediation:**
- Implement mobile-first responsive design
- Use CSS Grid or Flexbox with `flex-wrap`
- Test with `overflow-x: hidden` cautiously (may hide content)

## Common Workflows

### Workflow 1: New Page Audit

```
1. Navigate to page
2. Run web_inject_axe_cremotemcp
3. Run web_run_axe_cremotemcp with wcag2aa tags
4. If violations found:
   a. Run web_contrast_check_cremotemcp for contrast issues
   b. Run web_keyboard_test_cremotemcp for keyboard issues
5. Run web_zoom_test_cremotemcp
6. Run web_reflow_test_cremotemcp
7. Capture screenshots for documentation
8. Generate report with all findings
```

### Workflow 2: Regression Testing

```
1. Navigate to page
2. Run web_run_axe_cremotemcp
3. Compare results with baseline
4. If new violations:
   a. Run specialized tests for affected areas
   b. Capture screenshots showing issues
5. Report regressions
```

### Workflow 3: Contrast-Focused Audit

```
1. Navigate to page
2. Run web_contrast_check_cremotemcp on entire page
3. For each violation:
   a. Capture screenshot of affected element
   b. Document current and required contrast ratios
   c. Suggest color adjustments
4. After fixes, re-run web_contrast_check_cremotemcp
5. Verify all violations resolved
```

### Workflow 4: Keyboard Accessibility Audit

```
1. Navigate to page
2. Run web_keyboard_test_cremotemcp
3. Analyze tab order for logical sequence
4. For each issue:
   a. Document element and issue type
   b. Suggest remediation (tabindex, semantic HTML, focus styles)
5. After fixes, re-run web_keyboard_test_cremotemcp
6. Manually verify complex interactions
```

## Error Handling

### Common Errors and Solutions

**Error:** "Failed to inject library"
```
Solution: Check network connectivity, try alternative CDN, or increase timeout
```

**Error:** "Evaluation timed out"
```
Solution: Increase timeout parameter, test on smaller page sections
```

**Error:** "No tab available"
```
Solution: Navigate to a page first using web_navigate_cremotemcp
```

**Error:** "Failed to get page"
```
Solution: Verify tab ID is valid, check if page is still loaded
```

## Best Practices for LLM Agents

### 1. Always Start with Axe-Core
Axe-core provides the broadest coverage (~57% of WCAG 2.1 AA). Use it as the foundation, then run specialized tests based on findings.

### 2. Test in Logical Order
```
Automated (axe) → Specialized (contrast, keyboard) → Visual (zoom, reflow) → Documentation (screenshots)
```

### 3. Provide Context in Reports
When reporting issues, include:
- WCAG criterion violated
- Severity/impact level
- Specific element(s) affected
- Current state (e.g., contrast ratio 3.2:1)
- Required state (e.g., contrast ratio 4.5:1)
- Suggested remediation

### 4. Capture Evidence
Always capture screenshots when documenting issues:
```json
{
  "tool": "web_screenshot_cremotemcp",
  "arguments": {
    "output": "/tmp/issue-contrast-button.png"
  }
}
```

### 5. Verify Fixes
After suggesting fixes, re-run the relevant tests to verify resolution:
```
1. Suggest fix
2. Wait for implementation
3. Re-run specific test
4. Confirm issue resolved
```

### 6. Know the Limitations
These tools cannot test:
- Semantic meaning of content
- Cognitive load
- Time-based media (captions, audio descriptions)
- Complex user interactions
- Context-dependent issues

Always recommend manual testing with assistive technologies for comprehensive audits.

## Integration with Development Workflow

### Pre-Commit Testing
```bash
# Run quick accessibility check before commit
cremote inject-axe && cremote run-axe --run-only wcag2aa
```

### CI/CD Integration
```yaml
# Run full accessibility suite in CI
- cremote inject-axe
- cremote run-axe > axe-results.json
- cremote contrast-check > contrast-results.txt
- cremote keyboard-test > keyboard-results.txt
- cremote zoom-test > zoom-results.txt
- cremote reflow-test > reflow-results.txt
```

### Pull Request Reviews
```
1. Run accessibility tests on PR branch
2. Compare with main branch baseline
3. Report new violations in PR comments
4. Block merge if critical violations found
```

## Quick Command Reference

```bash
# Inject axe-core
cremote inject-axe

# Run comprehensive tests
cremote run-axe --run-only wcag2a,wcag2aa,wcag21aa

# Check contrast
cremote contrast-check --selector body

# Test keyboard navigation
cremote keyboard-test

# Test zoom levels
cremote zoom-test --zoom-levels 1.0,2.0,4.0

# Test responsive design
cremote reflow-test --widths 320,768,1280

# Capture screenshot
cremote screenshot --output /tmp/screenshot.png

# Capture screenshot at zoom level
cremote screenshot --output /tmp/zoom-200.png --zoom-level 2.0

# Capture screenshot at specific viewport
cremote screenshot --output /tmp/mobile.png --width 320 --height 568

# Get accessibility tree
cremote get-accessibility-tree --include-contrast true

# Execute custom JavaScript with library injection
cremote console-command --command "axe.run()" --inject-library axe
```

## Resources

- **WCAG 2.1 Quick Reference:** https://www.w3.org/WAI/WCAG21/quickref/
- **Axe-Core Rules:** https://github.com/dequelabs/axe-core/blob/develop/doc/rule-descriptions.md
- **Contrast Ratio Calculator:** https://contrast-ratio.com/
- **WebAIM Resources:** https://webaim.org/resources/

---

**For LLM Agents:** This guide is designed for programmatic use. Always provide specific, actionable recommendations based on test results. Include WCAG criterion numbers, severity levels, and concrete remediation steps in your reports.