a11y-building-harness

Fail-closed axe-core scan of a live URL, plus compact APG cards over MCP. An automated pass is not WCAG conformance.

Requires Node.js 22.18+ (see .nvmrc). Chromium is not in the npm tarball; install it once per machine: npx playwright install chromium.

Commands: npx a11y-building-harness@0.1.0 --help

npx a11y-building-harness@0.1.0 verify http://127.0.0.1:5173/
npx a11y-building-harness@0.1.0 verify --allow-remote https://example.com/
npx a11y-building-harness@0.1.0 get-blueprints modal button

verify defaults to loopback http(s). --allow-remote allows other http(s) hosts. file: and link-local/metadata hosts are always rejected. Exit codes: 0 clean, 1 violations or runtime error, 2 bad usage or disallowed URL.

Cursor MCP

Pin the package version. Until it is on the registry, use the clone form.

{
  "mcpServers": {
    "a11y-building-harness": {
      "command": "npx",
      "args": ["-y", "a11y-building-harness@0.1.0", "mcp"]
    }
  }
}

{
  "mcpServers": {
    "a11y-building-harness": {
      "command": "node",
      "args": ["bin/cli.mjs", "mcp"],
      "cwd": "/absolute/path/to/a11y-building-harness"
    }
  }
}

Tool: get_blueprints (button, modal, dialog, …). MCP does not run verify.

Publish (maintainers)

npm login
npm pack --dry-run
npm publish

If the name is taken, change "name" in package.json. After publish, pin @0.1.0 (or later) in MCP config — do not use an unpinned npx -y a11y-building-harness.

Related MCP server: agentic-patterns

Demo app (this repo only)

Not in the npm tarball. npm install && npx playwright install chromium && npm run dev, then verify against http://127.0.0.1:5173/. / should pass the harness axe tags; /broken must fail (image-alt, label). npm test from a clone.