WAI-ARIA: Authoring Practices Guide

This repository maintains the WAI-ARIA Authoring Practices Guide (APG).

• Published at: w3.org/wai/aria/apg
• Developed by the Authoring Practices Task Force of the ARIA Working Group
• Staff contact: Daniel Montalvo

Please do not provide commit access to this repository without coordination.

How the work is organized

• Work is planned and prioritized in our milestones. Each milestone corresponds to a working draft or release published to w3.org.
• Work is organized by topic in our projects. Each project corresponds to a type of design pattern or section of guidance.
• The scope of work and roadmap are described in the project wiki.

MCP Server (AI and Chatbot Integration)

The repository includes a Model Context Protocol (MCP) server that exposes WAI-ARIA pattern documentation as on-demand resources. AI agents and chatbots can fetch pattern specs (keyboard interaction, ARIA roles, states, and properties) when helping developers build accessible components.

Prerequisites: Node.js and npm install.

Run from cloned repo:

npm run mcp

Use with Cursor: Add to your MCP settings (e.g. in Cursor settings or .cursor/mcp.json):

{
  "mcpServers": {
    "wai-aria-apg": {
      "command": "node",
      "args": ["/path/to/aria-practices/mcp-server/index.mjs"]
    }
  }
}

Replace /path/to/aria-practices with the actual path to your cloned repository. The AI can then fetch pattern specs via resources like apg://pattern/accordion or apg://pattern/combobox.

For other MCP-compatible clients, see the Model Context Protocol documentation.

Cursor Skill: Copy skill/wai-aria-apg to .cursor/skills/ in your project so the AI uses APG patterns when building accessible components. See skill/README.md.

Contributing

1. Comment in an existing issue or raise a new issue, expressing your willingness to help and briefly summarizing the nature of your proposed resolution.
2. An editor will confirm there are no conflicting plans and, if needed, provide guidance.
3. Be sure you have linters installed and configured as described below.
4. Read our wiki page about submitting pull requests.
5. Do some fabulous work and submit a pull request.

Note: Please feel free to ask questions either through an issue or on the Authoring Practices Task Force mailing list.

Code conformance

This repository utilizes linting tools to do static code analysis and ensure consistent code quality across HTML, CSS, and JavaScript. Each linting tool and respective code standards are documented below and in the code guide.

Pull requests that contain linting errors will not be merged until the errors are resolved. To make this easier, you can install and run the tools locally before pushing code. Also note that the tools for CSS and JavaScript will automatically fix many issues if you have them installed locally. To install these tools:

1. Make sure that you have Node.js installed, which comes with node package manager (npm)
2. Open the directory that contains your aria-practices repository in a terminal
3. Run npm install

The HTML validator also requires the installation of a JDK in order to run. If you don't already have a JDK installed, download the latest JDK from Oracle.

It is also highly recommended that you use a code editor that supports these tools and EditorConfig.

HTML

HTML is validated against the NU HTML Validator. Should a warning or error occur because a future ARIA feature is not yet implemented, it will be added to the .vnurc file, allowing the error to pass through.

Run locally:

npm run lint:html

CSS

CSS is validated by stylelint using the stylelint-config-standard ruleset.

NOTE: on commit, stylelint will be run on staged CSS files. If errors are found that can be automatically fixed with the --fix flag, they will be fixed and the changes committed.

Run locally:

npm run lint:css

JavaScript

JavaScript is validated by ESLint, using our own config.

NOTE: on commit, eslint will be run on staged CSS files. If errors are found that can be automatically fixed with the --fix flag, they will be fixed and the changes committed.

Run locally:

npm run lint:js

Test and fix your code

1. Open a terminal window to the directory that contains the aria-practices repository
2. The repository has a script defined that will test all JavaScript in the examples directory. To run it, execute the command npm test. Note: this may take a few minutes to run and will open several browser windows during the test that will gain focus.
3. Many errors can be fixed automatically with the command npm run fix.
4. After running fix, test again to see what you need to fix manually.

When the linter encounters errors, it will report them in the console. The error report will contain the file name and line number, and it will indicate the character or place in the line that raised the style violation. To fix an error, satisfy the change that the violation indicates.

For example, here is an error for an invalid variable name style. Variables must follow a camelCase convention.

/Users/user1/Documents/github/aria-practices/examples/slider/js/text-slider.js
  19:8  error  Identifier 'value_nodes' is not in camel case  camelcase

The error occurred in examples/slider/js/text-slider.js, on line 19 and the offending character is indicated by the number 8 after the colon. Change the variable value_nodes to valueNodes in your source file to eliminate this error.

To see the complete list of style rules that are applied by ESLint, review the .eslintrc.json file in the root of the project.

Editorial documentation

See the APG Editorial Style Guidelines for information about writing prose for the APG. The ReadMe for the ARIA specification contains additional useful editorial guidance.