a11y

The a11y MCP server provides accessibility auditing capabilities powered by axe-core. It exposes two primary tools: audit_webpage, which runs a detailed accessibility audit on a target URL and can optionally include HTML snippets, and get_summary, which returns a concise accessibility summary for a given page. You can integrate this server into an agentic loop with your preferred AI assistants to identify, summarize, and fix WCAG-related issues as part of your automated QA or development workflow.

To use audit_webpage, provide the target URL and optional parameters such as includeHtml (to embed HTML snippets in results) and tags (to filter checks by WCAG criteria like wcag2a, wcag2aa, wcag21a, or best-practice). Example prompts might be: "Audit https://example.com for accessibility issues" or "Audit http://localhost:3000 with includeHtml true". To get a high-level view, use get_summary with a URL to retrieve a concise report of accessibility issues on that page.

Prerequisites:

• Node.js and npm installed on your system
• Access to npm or npx

Installation steps:

1. Install the a11y-mcp package globally so you can run the MCP server from anywhere:

npm install -g a11y-mcp

2. Run the MCP server directly using npx (as shown in the README):

npx a11y-mcp

3. Alternatively, install locally and start the server in development mode:

git clone <repository-url>
cd <repository-directory>
npm install
npm start

4. If you intend to release or publish, use the provided release scripts as documented in the repository:

chmod +x release.sh
./release.sh

Notes and tips:

• The server uses axe-core for accessibility checks, so results reflect the capabilities and rules defined by axe-core at the time of execution.
• In MCP configuration, you can disable the server or customize auto-approval behavior by setting disabled and autoApprove as needed.
• Ensure your environment has network access if auditing remote pages, and consider rate limiting in automated workflows to avoid excessive requests.
• If you encounter path or command resolution issues with npx, verify that npm is correctly installed and that the a11y-mcp package is accessible in your PATH.
• The npm package name for this server is a11y-mcp; use the package name when referencing in scripts or in npx commands.