aria-apg
WAI-ARIA Authoring Practices Guide
This skill packages the W3C WAI-ARIA Authoring Practices Guide (APG) as an accessibility assessment knowledge base. APG documents the keyboard interaction, ARIA roles, states, and properties for the common interactive widget patterns that web authors implement. The skill groups 44 design patterns into seven families (Disclosure, Combobox, Grid, Menu, Tabs, Treegrid, and Dialog) and points the Accessibility Skill Assessor subagent at the per-family reference files in references/ when a finding involves a specific pattern.
APG is non-normative implementation guidance that operationalises the normative WAI-ARIA specification, so APG patterns sit alongside the wcag-22 skill: APG describes how to build the widget, WCAG 2.2 describes which behaviours the finished widget must satisfy. Assessor subagents typically cite both — the APG pattern for the widget contract and the relevant WCAG 2.2 success criterion for the user-facing requirement.
Source: W3C WAI-ARIA Authoring Practices Guide, https://www.w3.org/WAI/ARIA/apg/. APG content is published under the W3C Document License. Per the repository licensing posture in .github/instructions/accessibility/accessibility-license-posture.instructions.md, pattern summaries in this skill are paraphrased in the authors' own words and every reference file links to the canonical W3C pattern URL for verification.