a11y-mcp

MCP server for running axe-core accessibility audits. Uses Camoufox to bypass Cloudflare and other bot protection.

Install

# Claude Code
claude mcp add a11y -- uvx a11y-mcp

# Or with pip
pip install a11y-mcp

Configuration

For Claude Desktop, add to your config (~/Library/Application Support/Claude/claude_desktop_config.json on macOS):

{
  "mcpServers": {
    "a11y": {
      "command": "uvx",
      "args": ["a11y-mcp"]
    }
  }
}

<details> <summary>Other editors (Cursor, VS Code, Zed, etc.)</summary>

Most editors use the same format. Add to your MCP config:

{
  "mcpServers": {
    "a11y": {
      "command": "uvx",
      "args": ["a11y-mcp"]
    }
  }
}

Config locations:

• Cursor: ~/.cursor/mcp.json
• VS Code (Continue): .continue/config.json under experimental.modelContextProtocolServers
• VS Code (Cline): Cline MCP settings
• Zed: ~/.config/zed/settings.json under context_servers

</details>

Tools

Tool	Description
scan_page	Scan a URL for WCAG violations
scan_element	Scan a specific CSS selector
get_violations	Get detailed violation info from last scan
get_full_report	Full axe results (violations, passes, incomplete)
export_report	Export as JSON, HTML, or CSV
set_wcag_level	Set WCAG level (A, AA, AAA, 21A, 21AA, 22AA)
configure_rules	Enable/disable specific axe rules

Usage

> Scan https://example.com for accessibility issues

> Export an HTML report for the last scan

> Check WCAG 2.2 AA compliance for https://adobe.com

WCAG Levels

Level	Standard
A, AA, AAA	WCAG 2.0
21A, 21AA	WCAG 2.1
22AA	WCAG 2.2

Default is AA.

Cloudflare Bypass

This uses Camoufox, an anti-detect browser with fingerprint spoofing at the C++ level. It handles JavaScript challenges, Turnstile, and most bot detection automatically.

On first run, Camoufox downloads a browser binary (~300MB).

Requirements

• Python 3.10+
• macOS, Linux, or Windows

Troubleshooting

Browser won't launch: Run python -c "import camoufox; camoufox.install()"

Cloudflare still blocking: Some sites have aggressive detection. The first visit may require manual verification.

axe-core won't inject: Likely a strict CSP. Try a different page on the same domain.

Development

git clone https://github.com/anthropics/a11y-mcp && cd a11y-mcp
uv venv && source .venv/bin/activate
uv pip install -e ".[dev]"
python -m camoufox fetch
pytest

Debug with the MCP inspector:

npx @modelcontextprotocol/inspector uvx a11y-mcp

License

MIT License - see LICENSE for details.

Credits

• axe-core - Accessibility testing engine by Deque
• Camoufox - Anti-detect browser
• MCP - Model Context Protocol by Anthropic

Related Projects

• mcp-server-fetch - Web content fetching
• mcp-server-puppeteer - Browser automation
• mcp-server-playwright - Playwright browser control