MCP Web A11y MCP Server

MCP server for web accessibility analysis using axe-core

Local serverstdioTypeScript

What is the MCP Web A11y MCP server?

MCP Web A11y MCP server is a locally run integration for AI assistants that speak the Model Context Protocol. MCP server for web accessibility analysis using axe-core.

What you get

An MCP (Model Context Protocol) server that provides web accessibility analysis capabilities using axe-core and Puppeteer.

  • Analyze web accessibility of any URL using axe-core
  • Simulate color blindness (protanopia, deuteranopia, tritanopia) using color matrices
  • Detailed reporting of accessibility violations
  • Support for custom user agents and selectors
  • Debug logging for troubleshooting
  • Comprehensive accessibility checks based on WCAG guidelines

What the assistant can call

Once MCP Web A11y is connected, these are the calls the assistant has available:

  • Parameters — The Parameters tool exposed by this server
  • Building — This will: 1. Compile TypeScript to JavaScript 2. Make the output file executable 3. Place the compiled files in the build directory
  • Debugging — The server includes detailed debug logging that can be observed in the console output. This includes: - Network requests and responses - Page loading

Setting it up

The server ships on npm as @smithery/cli, so your MCP client can launch it on demand — there is no separate build step. Add the server block to your client's configuration, restart it, and the tools register themselves.

Configuration and credentials

You will need one environment variable: MCP_OUTPUT_DIR. Keep credentials in your client's env block or a secrets manager rather than in a file you might commit.

  • Node.js (v14 or higher) - npm

Choosing this one

Plenty of developer tooling servers cover similar ground. The differences that matter in practice are scope of access and how much setup stands between you and a working tool call. MCP Web A11y's toolset — Parameters, Building, Debugging — is a fair guide to whether it matches your workflow. It is maintained by bilhasry-deriv; worth a glance at recent repository activity before you build anything load-bearing on it.

We check each listing at SyncDev against the project's documentation before it goes live — if something here drifts out of date, it is a bug worth reporting.

Before you rely on it

  • It runs with your machine's permissions. That is convenient and also the reason to think about what you point it at before you approve a tool call.
  • MCP clients confirm each tool call by default. Leave that on until you have watched what the mcp web a11y mcp server does with a few real requests.

Available tools

ToolWhat it does
ParametersThe Parameters tool exposed by this server.
BuildingThis will: 1. Compile TypeScript to JavaScript 2. Make the output file executable 3. Place the compiled files in the build directory
DebuggingThe server includes detailed debug logging that can be observed in the console output. This includes: - Network requests and responses - Page loading status - Selector waiting status - Any console messages from the analy

How to install the MCP Web A11y MCP server

{
  "mcpServers": {
    "web-a11y": {
      "command": "npx",
      "args": ["-y", "@smithery/cli"],
      "env": {
        "MCP_OUTPUT_DIR": "your-value"
      }
    }
  }
}

Add to claude_desktop_config.json, then restart Claude Desktop.

Configuration

  • Node.js (v14 or higher) - npm
VariableDescriptionRequired
MCP_OUTPUT_DIRFilesystem location the server is allowed to use.Optional

Example prompts to try

  • Use MCP Web A11y to Parameters.
  • Use MCP Web A11y to Building.
  • Use MCP Web A11y to Debugging.

Frequently asked questions

It connects MCP Web A11y to MCP-compatible AI assistants such as Claude and Cursor, exposing 3 tools (Parameters, Building, Debugging) that the assistant can call on your behalf. Instead of copying data back and forth by hand, the assistant works with MCP Web A11y directly.