/kb-web-scanning

name: kb-web-scanning
description: Reference data, not a reviewer. Web content discovery, URL crawling, and page inventory for accessibility audits. Use when scanning web pages, crawling sites for audit scope, or building page inventories for multi-page audits.
license: MIT
disable-model-invocation: true
user-invocable: false
metadata:
  tier: reference
  domain: cross-cutting
  output: none
  effort: low
  title: Web Scanning

Web Scanning

Supported Audit Methods

Each method, with tool and when to use.

| Method | Tool | When to Use | |--------|------|-------------| | Runtime scan | axe-core CLI | Live URL available (dev server or production) | | Code review | Agent specialists | Source code available in workspace | | Both | axe-core + agents | Most comprehensive - catches issues from both angles |

Runtime Scanning Commands

axe-core CLI

# Single page scan (WCAG 2.2 AA)
npx @axe-core/cli <URL> --tags wcag2a,wcag2aa,wcag21a,wcag21aa

# Save results to JSON
npx @axe-core/cli <URL> --tags wcag2a,wcag2aa,wcag21a,wcag21aa --save ACCESSIBILITY-SCAN.json

# Multiple pages
npx @axe-core/cli <URL1> <URL2> <URL3> --tags wcag2a,wcag2aa,wcag21a,wcag21aa --save ACCESSIBILITY-SCAN.json

# With Chrome flags (headless)
npx @axe-core/cli <URL> --tags wcag2a,wcag2aa,wcag21a,wcag21aa --chrome-flags="--headless --no-sandbox"

axe-core Tag Reference

Each tag, with its standard.

| Tag | Standard | |-----|----------| | wcag2a | WCAG 2.0 Level A | | wcag2aa | WCAG 2.0 Level AA | | wcag21a | WCAG 2.1 Level A | | wcag21aa | WCAG 2.1 Level AA | | wcag22aa | WCAG 2.2 Level AA | | best-practice | Best practices (not WCAG required) |

Screenshot Capture

capture-website-cli (preferred - lightweight)

# Full-page screenshot
npx capture-website-cli "<URL>" --output="screenshots/<page>.png" --full-page --type=png

# With viewport
npx capture-website-cli "<URL>" --output="screenshots/<page>.png" --full-page --width=1280 --height=720

# Mobile viewport
npx capture-website-cli "<URL>" --output="screenshots/<page>-mobile.png" --full-page --width=375 --height=812

# With delay for JS-rendered content
npx capture-website-cli "<URL>" --output="screenshots/<page>.png" --full-page --delay=3

Playwright (fallback)

npx playwright screenshot --browser chromium --full-page --wait-for-timeout 3000 "<URL>" "screenshots/<page>.png"

Page Discovery for Multi-Page Audits

Crawl Depth Modes

Each mode, with its behavior and max pages.

| Mode | Behavior | Max Pages | |------|----------|-----------| | Current page only | Scan single URL | 1 | | Key pages | User-provided list | User-defined | | Full site crawl | Follow internal links | 50 (default cap) |

Sitemap-based Discovery

# Check for sitemap
curl -s <BASE_URL>/sitemap.xml | head -20

# Extract URLs from sitemap
curl -s <BASE_URL>/sitemap.xml | grep -oP '<loc>\K[^<]+' | head -50

Link-based Crawling

When crawling from a start URL:

• Follow only same-domain links
• Skip anchor links (#), mailto:, tel:, javascript: links
• Skip file downloads (.pdf, .zip, .doc, etc.)
• Respect robots.txt
• Cap at 50 pages unless user overrides
• Track visited URLs to avoid duplicates

Framework Detection

Detect the framework from workspace files to enable framework-specific scanning:

| Indicator | Framework | |-----------|-----------| | `package.json` contains `react` | React | | `package.json` contains `next` | Next.js | | `package.json` contains `vue` | Vue | | `package.json` contains `@angular/core` | Angular | | `package.json` contains `svelte` | Svelte | | `.jsx` / `.tsx` files present | React/Next.js | | `.vue` files present | Vue | | `angular.json` present | Angular | | `.svelte` files present | Svelte | | Only `.html` files | Vanilla HTML |

Source Code File Patterns

When doing code review, scan these file patterns:

# HTML files
**/*.html

# Component files (framework-specific)
**/*.jsx
**/*.tsx
**/*.vue
**/*.svelte
**/*.component.ts
**/*.component.html

# Style files (for contrast/visual checks)
**/*.css
**/*.scss
**/*.less
**/*.module.css

# Config files (for framework detection)
package.json
next.config.*
nuxt.config.*
angular.json
svelte.config.*
tailwind.config.*

Scan Configuration

Web Scan Config File: `.a11y-web-config.json`

{
  "profile": "standard",
  "wcagLevel": "AA",
  "wcagVersion": "2.2",
  "axeTags": ["wcag2a", "wcag2aa", "wcag21a", "wcag21aa"],
  "maxPages": 50,
  "screenshots": false,
  "framework": "auto",
  "ignore": {
    "paths": ["node_modules/**", "dist/**", "build/**", ".next/**"],
    "rules": []
  }
}

Scan Profiles

Each profile, with its phases and thoroughness.

| Profile | Phases | Thoroughness | |---------|--------|-------------| | Quick | 1, 3, 4, 9 | Errors and critical only | | Standard | All (1-9) | Errors and warnings | | Deep | All + extras | All severities + animation, cognitive, touch |