WCAG 2.2 Compliance

wcag-compliance-mcp

MCP server for WCAG 2.2 audits, verified remediation examples, and U.S. accessibility deadlines. Four tools, no API keys, no network calls, all data bundled.

Built from a benchmark that was verified in headless Chromium: 64 fail/pass HTML pairs executed against axe-core 4.14.0, all 87 WCAG 2.2 success criteria, and 21 sourced regulatory dates from the 1990 ADA through the 2028 DOJ Title II deadline.

[DOI]

Listed in the official MCP registry as io.github.Veduis/wcag-compliance-mcp, on the 97k star MCP directory, and in the accessibility tools list.

Tools

audit_html_snippet

18 static checks over a fragment or full document:

Every finding returns the criterion, the offending markup, and a corrected snippet.

check_ada_compliance_deadlines

Entity types: title_ii_large, title_ii_small, title_iii_business, federal_contractor, hhs_recipient, eu_business, ontario.

Pass as_of to compute the answer for any date, which makes the tool useful for retroactive scoping and for legal memos that need to state what applied on a given day. Every date carries its primary source URL.

Install

npx -y github:Veduis/wcag-compliance-mcp

Three other routes:

The npm package wcag-compliance-mcp lands with the next publish. Until then the GitHub spec installs the same code and dependencies.

Claude Desktop

~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or %APPDATA%\Claude\claude_desktop_config.json (Windows):

{  "mcpServers": {    "wcag-compliance": {      "command": "npx",      "args": ["-y", "github:Veduis/wcag-compliance-mcp"]    }  }}

Cursor

.cursor/mcp.json:

{  "mcpServers": {    "wcag-compliance": {      "command": "npx",      "args": ["-y", "github:Veduis/wcag-compliance-mcp"]    }  }}

VS Code (Copilot agent mode)

.vscode/mcp.json:

{  "servers": {    "wcag-compliance": {      "command": "npx",      "args": ["-y", "github:Veduis/wcag-compliance-mcp"]    }  }}

Docker

docker build -t wcag-compliance-mcp .docker run -i --rm wcag-compliance-mcp

Example

Ask your agent:

Audit this pricing page for WCAG 2.2 issues and give me the corrected markup.

The agent calls audit_html_snippet, then get_verified_fix_example for each failing criterion. What comes back is a failing snippet, the corrected snippet, and the manual test step, not a vague warning.

$ audit_html_snippet('<img src="chart.png">')
{  "summary": {    "issues": 1,    "checks_run": 18,    "checks_failed": 1,    "conformance_claim": false  },  "findings": [    {      "check_id": "img-alt",      "sc": "1.1.1",      "level": "A",      "title": "Image missing a text alternative",      "count": 1,      "elements": [        {          "snippet": "<img src=\"chart.png\">",          "reason": "No alt, aria-label, or aria-labelledby. Decorative images need alt=\"\"."        }      ],      "fix": "<img src=\"chart.png\" alt=\"Bar chart: Q3 revenue rose 18 percent over Q2\">"    }  ]}

What automation cannot see

This matters more than the feature list. In the benchmark behind this server, axe-core 4.14.0 flagged 39 of 64 deliberately defective documents. The other 25 needed scripted checks or a human. Across the full standard, 29 of 87 criteria have a mapped rule and 58 have none, and at Level AA, the level the law actually targets, only 7 of 24 criteria have a rule.

So the server reports conformance_claim: false on every audit. A clean result means no static defect was found, not that the page conforms. Contrast, focus visibility, keyboard traps, reading order, captions accuracy, and error recovery all need a rendered page or a person. If you need a full-domain audit with those checks, that is what vComplianceScanner does.

Data provenance

Mirrors: Hugging Face. Test cases are CC BY 4.0, code is MIT.

Development

npm installnpm test          # 18 checks, including a live stdio handshakenpm start

Layout:

src/index.mjs    MCP server, tool registration, resourcesrc/checks.mjs   18 static checks, no browser requiredsrc/data.mjs     criteria, pairs, timeline, deadline resolutiondata/            bundled JSON, generated from the published datasetstest/smoke.mjs   engine tests plus protocol handshake

More from Veduis

• WCAG 2.2 developer implementation manual
• ADA Title II vs Title III: which law applies to a website
• ADA demand letter defense

License

MIT for the code. Dataset content is CC BY 4.0, attribution to Veduis LLC.