rgaa-mcp

MCP server that audits websites for RGAA 4.1.2 accessibility compliance. Connects to Claude Desktop and exposes two tools: automated page auditing and RGAA criteria lookup.

Tools

rgaa_audit

Audits a URL against RGAA 4.1.2 / WCAG 2.1 AA using Playwright + axe-core, then maps violations to RGAA criteria.

Inputs:

• url (required) — full URL to audit (e.g. https://example.com)
• viewport (optional) — "desktop" (1280×800, default) or "mobile" (375×667)

What it checks:

• axe-core rules: WCAG 2.0/2.1 A & AA + best practices
• Violations mapped to RGAA themes (Images, Couleurs, Liens, Formulaires, Structure, Navigation…)
• Behavioral checks: horizontal scroll at 320px (RGAA 10.11), text spacing overflow (RGAA 10.12), meta refresh (RGAA 13.1)

Output: Markdown report with violation summary, per-theme breakdown, affected HTML elements, and fix guidance.

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rgaa_criterion

Returns the full definition of a RGAA 4.1.2 criterion, fetched live from the official DISIC repository (with local fallback).

Input:

• id (required) — criterion ID in "theme.number" format (e.g. "1.1", "3.2", "11.13")

Output: criterion title, WCAG level, WCAG references, tests, special cases, technical notes, and test methodology.

Installation

Claude Code (CLI)

claude mcp add rgaa-mcp -- node "/path/to/rgaa-analyzer-mcp/dist/server.js"

The rgaa_audit and rgaa_criterion tools will be available in your conversations.

Local development

npm install
npm run build      # Compile TypeScript → dist/
npm run dev        # Run with tsx (no compile step)
npm start          # Run compiled dist/server.js

Verify the server starts correctly:

node dist/server.js   # Should print "RGAA MCP Server running" to stderr

Tech stack

• Model Context Protocol SDK — MCP server transport
• Playwright — headless Chromium for page rendering
• axe-core — automated accessibility rule engine
• Zod — input validation
• TypeScript — ES2022, NodeNext modules, strict mode

Notes

• stdout is reserved for the MCP protocol. All logging goes to stderr.
• RGAA criteria data is fetched live from DISIC/accessibilite.numerique.gouv.fr and cached in memory for the lifetime of the process. A local fallback covers the most common criteria if the network is unavailable.
• axe-core is injected directly from node_modules to avoid CSP issues with CDN URLs.