Accessibility Testing MCP
An MCP server for accessibility testing using axe-core and IBM Equal Access. Choose your testing engine or use both for comprehensive coverage.
Example Prompts
"Test the accessibility of https://example.com"
"Test the accessibility of https://example.com" blockers only output issues in chat: What is the Issue, Who it Impacts, How to Fix, WCAG, Severity, Code Snippet"
Dual Engine Support
Axe-core (Deque) - Industry standard, zero false positives
IBM Equal Access - Comprehensive IBM accessibility requirements
Multi-Screen Testing
Test at multiple viewport sizes to catch responsive accessibility issues.
Tools
Tool | Description |
| Test any URL for accessibility issues |
| URL test with raw JSON output |
| Test HTML content directly |
| HTML test with raw JSON output |
| List available accessibility rules |
All tools accept an optional engine parameter ("axe" or "ace").
Installation
Configuration
Environment Variables
Configure via MCP config env section:
Variable | Values | Default | Description |
|
|
| Testing engine |
|
|
| WCAG version & level |
|
|
| Include best practices/recommendations |
| Comma-separated |
| Viewport sizes to test |
|
|
| Run browser in headless mode; set to |
The WCAG_LEVEL setting automatically configures both Axe-core tags and IBM Equal Access policies.
VS Code (GitHub Copilot)
Add to VS Code settings (JSON):
Claude Desktop
Add to claude_desktop_config.json:
Understanding Results
Axe-core Output
Violations: Definite accessibility failures
Incomplete: Needs manual review
Passes: Rules that passed
Inapplicable: Rules that don't apply
IBM Equal Access Output
Violations: Accessibility failures
Potential Violations: Needs review
Recommendations: Suggested improvements (when BEST_PRACTICES=true)
Manual Checks: Requires human testing
WCAG_LEVEL Values
Level | Description |
| WCAG 2.0 Level A |
| WCAG 2.0 Level AA |
| WCAG 2.1 Level A |
| WCAG 2.1 Level AA (default) |
| WCAG 2.1 Level AAA |
| WCAG 2.2 Level A |
| WCAG 2.2 Level AA |
| WCAG 2.2 Level AAA |
Dependencies
@modelcontextprotocol/sdk - MCP server framework
axe-core - Deque accessibility testing engine
accessibility-checker - IBM Equal Access engine
playwright - Headless browser automation
License
MIT