wcagc — accessibility scanning
Deterministic axe-core accessibility scans (WCAG 2.1 AA, EN 301 549, PDF/UA) via your account.
Install
Add this to your client's MCP configuration (Claude Desktop: claude_desktop_config.json; Cursor: .cursor/mcp.json; VS Code and others use the same "mcpServers" shape).
claude mcp add --transport http wcagc-accessibility-scanning 'https://mcp.wcagc.com/mcp'
{
"mcpServers": {
"wcagc-accessibility-scanning": {
"type": "http",
"url": "https://mcp.wcagc.com/mcp"
}
}
}
@wcagc/mcpclaude mcp add wcagc-accessibility-scanning -e 'WCAGC_MCP_KEY=<your wcagc_mcp_key>' -e 'WCAGC_API_BASE_URL=<WCAGC_API_BASE_URL>' -- npx -y @wcagc/mcp@0.8.0
{
"mcpServers": {
"wcagc-accessibility-scanning": {
"command": "npx",
"args": [
"-y",
"@wcagc/mcp@0.8.0"
],
"env": {
"WCAGC_MCP_KEY": "<your wcagc_mcp_key>",
"WCAGC_API_BASE_URL": "<WCAGC_API_BASE_URL>"
}
}
}
}
Environment variables
WCAGC_MCP_KEYrequired secret A wcagc API key with the mcp:scan scope. Mint one under Settings -> API keys; every plan can, with a daily quota on Free and Starter.WCAGC_API_BASE_URLThe wcagc API to call. Defaults to the hosted API; override only for a self-hosted deployment.
Documentation
From the project's README on GitHub, refreshed weekly. Links open on GitHub.
wcagc-mcp
An MCP server that lets an AI assistant (Claude, ChatGPT, or any MCP-compatible client) run real, deterministic accessibility scans through wcagc — axe-core under the hood, not an LLM guess. Every scan result carries an explicit coverage disclaimer and never claims "compliant": automated testing finds only a portion of accessibility barriers, and this tool says so in every response.
This package is a thin, stateless adapter. It holds no database, no scan logic, and no secrets beyond the wcagc API base URL — it translates MCP tool calls into HTTP calls against the wcagc API and forwards the caller's own bearer. All authentication, entitlements, quotas, and scan orchestration live in the API; this code is safe to read end to end.
Two ways to run it
Local (stdio) — for Claude Desktop, Cursor, or any MCP client that spawns a local process:
npx @wcagc/mcp
Configure your MCP client with:
{
"mcpServers": {
"wcagc": {
"command": "npx",
"args": ["-y", "@wcagc/mcp"],
"env": {
"WCAGC_MCP_KEY": "<your mcp:scan API key>"
}
}
}
}
Mint an mcp:scan key from your wcagc account under Settings → API keys — available on every
plan, with a daily quota on Free/Starter and unlimited on Pro/Agency.
Hosted (Streamable HTTP + managed OAuth) — what Claude web/desktop/mobile connectors and ChatGPT use, since neither runs a local process for you. Add this remote MCP connector:
https://mcp.wcagc.com/mcp
The client discovers /.well-known/oauth-protected-resource/mcp, opens the wcagc login/consent
flow, and binds the connection to one Organization. No key copy/paste is required. API-key bearer
authentication remains supported for local stdio and CI.
ChatGPT availability depends on the ChatGPT plan and on whether the client permits action tools;
scan_url creates a scan and is not a read-only operation. See
wcagc.com/integrations/mcp.
Tools
| Tool | Plan | What it does |
|---|---|---|
scan_url | all | Scan any public URL, or a registered site for full tracking (Pro+). |
check_pdf | all | Run a PDF/UA-1 structure check on a public PDF. |
get_scan · get_findings | all | Read a scan_url scan's status, severity counts, and findings — either kind, recorded or one-off. |
list_sites | Pro+ | List the account's registered sites. |
scan_site | Pro+ | Crawl and scan every reachable page of a registered site. |
get_run · get_run_findings | Pro+ | Read a full-site run from scan_site. |
get_root_causes | Pro+ | Group a run's repeated DOM patterns and return factual element/page blast radius. |
run_journey | Pro+ | Replay a saved multi-step journey and check each step. |
get_trends | Pro+ | Read a site's violation-count history over time. |
One id, one poll tool: whatever scan_url did with a URL, get_scan and get_findings read it
back. get_run and get_run_findings are only for full-site runs from scan_site.
Every scan-producing tool returns the coverage disclaimer in both the text content and the structured content. There is no score, grade, or conformance verdict — automated testing finds roughly 30–57% of accessibility issues, and the remainder needs manual review.
Configuration
| Env var | Used by | Meaning |
|---|---|---|
WCAGC_API_BASE_URL | both | The wcagc API to call. Defaults to https://api.wcagc.com; set it only when self-hosting. |
WCAGC_MCP_KEY | stdio | Your mcp:scan API key. |
PORT | hosted | Port to listen on (default 8080). |
WCAGC_MCP_ALLOWED_HOSTS | hosted | Comma-separated Host-header allowlist (DNS-rebinding protection when bound to 0.0.0.0). |
WCAGC_MCP_INTROSPECT_TTL_SECONDS | hosted | How long a verified bearer is cached before re-checking with the API (default 60). |
WCAGC_MCP_OAUTH_ISSUER | hosted | Expected OAuth issuer (defaults to WCAGC_API_BASE_URL). |
WCAGC_MCP_OAUTH_JWKS_URL | hosted | Authorization Server public JWKS URL. |
WCAGC_MCP_URL | hosted | Canonical RFC 9728 protected-resource URL (defaults to https://mcp.wcagc.com/mcp). |
WCAGC_MCP_JWKS_TTL_SECONDS | hosted | JWKS cache TTL; an unknown kid triggers an immediate refetch. |
WCAGC_OPENAI_APPS_CHALLENGE | hosted | OpenAI Plugins Directory domain-verification token; keep it in the deployment secret store, never in source. |
Development
Hosted HTTP requests to /mcp and discovery endpoints produce JSON logs with a generated
request ID, HTTP status, MCP method, error code and duration. Tokens, headers, query strings,
tool arguments and results are excluded. Health probes are not logged.
The Docker entrypoint preloads the New Relic ESM agent. Set NEW_RELIC_AGENT_ENABLED=true,
NEW_RELIC_APP_NAME=wcagc-mcp and the deployment secret NEW_RELIC_LICENSE_KEY to enable
APM and forwarding of these safe request logs. The license key must belong to the existing
New Relic account; never commit it. The stdio entrypoint does not load the agent.
npm install
npm run dev # hosted, watch mode
npm run start:stdio # stdio mode
npm run typecheck
npm run verify # node:test against a local fixture API
License
MIT — see LICENSE.
Frequently asked questions
What is wcagc — accessibility scanning?
Deterministic axe-core accessibility scans (WCAG 2.1 AA, EN 301 549, PDF/UA) via your account.
How do I install wcagc — accessibility scanning?
It runs as a remote server. In Claude Code: claude mcp add --transport http wcagc-accessibility-scanning 'https://mcp.wcagc.com/mcp'. For other clients, paste the JSON configuration from this page into their MCP settings.
Does wcagc — accessibility scanning need an API key?
Yes. It expects WCAGC_MCP_KEY, which you set in its configuration.
Is wcagc — accessibility scanning open source?
Yes. Its code is on GitHub under the MIT license.
Who maintains wcagc — accessibility scanning?
It is published by WCAG-Compliance. AI.tn lists it but does not maintain or endorse it.
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