mcp-accessibility-scanner

MCP Accessibility Scanner 🔍

A Model Context Protocol (MCP) server that provides automated web accessibility scanning using Playwright and Axe-core. This server enables LLMs to perform WCAG compliance checks, capture annotated screenshots, and generate detailed accessibility reports.

Features

✅ Full WCAG 2.1/2.2 compliance checking
🖼️ Automatic screenshot capture with violation highlighting
📄 Detailed JSON reports with remediation guidance

Installation

You can install the package using any of these methods:

Using npm:

npm install -g mcp-accessibility-scanner

Docker Installation

The project includes a Dockerfile that sets up all necessary dependencies including Node.js v22 and Python 3.13.

1. Build the Docker image:

docker build -t mcp-server . 

2. Run the container:

docker run -it -e MCP_PROXY_DEBUG=true mcp-server

You can also run it in the background:

docker run -d -p 3000:3000 mcp-server

Installation in VS Code

Install the Accessibility Scanner in VS Code using the VS Code CLI:

For VS Code:

code --add-mcp '{"name":"accessibility-scanner","command":"npx","args":["mcp-accessibility-scanner"]}'

For VS Code Insiders:

code-insiders --add-mcp '{"name":"accessibility-scanner","command":"npx","args":["mcp-accessibility-scanner"]}'

Configuration

Here's the Claude Desktop configuration:

{
  "mcpServers": {
    "accessibility-scanner": {
      "command": "npx",
      "args": ["-y", "mcp-accessibility-scanner"]
    }
  }
}

Usage

The scanner exposes a single tool scan_accessibility that accepts:

• url: The webpage URL to scan (required)
• violationsTag: Array of accessibility violation tags to check (required)
• viewport: Optional object to customize the viewport size
  • width: number (default: 1920)
  • height: number (default: 1080)
• shouldRunInHeadless: Optional boolean to control headless mode (default: true)

Note: When running a scan, an annotated screenshot highlighting any accessibility violations will be automatically saved to your downloads folder.

Example usage in Claude:

Could you scan example.com for accessibility issues related to color contrast?

Advanced example with custom options:

Could you scan example.com for accessibility issues with a viewport of 1280x720 and show the browser window?

Development

Clone and set up the project:

git clone https://github.com/JustasMonkev/mcp-accessibility-scanner.git
cd mcp-accessibility-scanner
npm install

Start the TypeScript compiler in watch mode:

npm run watch

Test the MCP server locally:

npm run inspector

Docker Development

For development using Docker:

1. Build the development image:

docker build -t mcp-server-dev .

2. Run with volume mounting for live code changes:

docker run -it -v $(pwd):/app -p 3000:3000 -e MCP_PROXY_DEBUG=true mcp-server-dev

Project Structure

├── src/              # Source code
│   ├── index.ts     # MCP server setup and tool definitions
│   └── scanner.ts   # Core scanning functionality
├── build/           # Compiled JavaScript output
├── Dockerfile       # Docker configuration for containerized setup
├── package.json     # Project configuration and dependencies
└── tsconfig.json    # TypeScript configuration

License

MIT