Programmatic access to W3C Accessibility Conformance Testing (ACT) Rules. Loaded from snapshotted YAML/Markdown source files in the act-rules.github.io repository.

ACT rules are tool-agnostic accessibility test rules. Each rule maps to one or more WCAG Success Criteria and includes a precise applicability statement. Together, they’re the closest thing to a published “which SCs apply to which UI elements” mapping.

Install

npm install act-rules-query

Usage

import {
  getRule, listRules, rulesByWCAG, search, ACT_SNAPSHOT,
} from 'act-rules-query'

const r = getRule('97a4e1')
console.log(r.name)             // 'Button has non-empty accessible name'
console.log(r.wcag_sc_ids)      // ['4.1.2']
console.log(r.applicability_text)
//  'This rule applies to elements that are included in the accessibility tree
//   and have a semantic role of `button`...'

rulesByWCAG('4.1.2')             // → ACT rules covering "Name, Role, Value" (mechanical, front-matter)
search('button')                 // → rules whose name or applicability text mentions "button"

Data shape

interface ACTRule {
  id: string                     // hex slug, e.g. '97a4e1'
  name: string                   // verbatim from front-matter
  rule_type: 'atomic' | 'composite'
  description: string            // verbatim from front-matter
  wcag_sc_ids: string[]          // primary WCAG SC IDs (forConformance: true)
  wcag_sc_ids_secondary: string[]
  input_aspects: string[]
  applicability_text: string     // verbatim '## Applicability' section
  expectations: string[]         // each '## Expectation' — what must hold to pass
  examples: ACTExample[]         // worked Passed / Failed / Inapplicable examples, with code
  background: string             // '## Background' prose
  assumptions: string            // 'Assumptions' section
  accessibility_support: string  // 'Accessibility Support' section
  url: string                    // canonical at act-rules.github.io
}

interface ACTExample {
  category: 'passed' | 'failed' | 'inapplicable'
  name: string                   // e.g. 'Passed Example 1'
  description: string            // verbatim prose
  code: string                   // the example's code (first fenced block)
}

Every field is verbatim from the snapshotted Markdown — the full rule (applicability, expectations, examples, background), not just its applicability.

Methodology

Unlike apg-query and wcag-query (which scrape HTML), act-rules-query reads YAML/Markdown source files directly from a snapshot of the upstream repo. The “loader” is just YAML parsing — no HTML, no cheerio, no fragility against rendering changes.

To refresh:

# 1. Sync upstream snapshot (manual today; could be a script)
git clone https://github.com/act-rules/act-rules.github.io /tmp/act
cp /tmp/act/_rules/*.md packages/act-rules-query/snapshots/_rules/

# 2. Re-run the loader
npm run load --workspace=act-rules-query

The loader writes src/data/<rule-id>.json per rule plus a _manifest.json index and a _snapshot.json with date + upstream commit hash.

Coverage

v0 ships 94 rules snapshotted from act-rules/act-rules.github.io@80e887e. ACT is actively maintained — refreshing the snapshot pulls in new rules.

search(query) is a plain case-insensitive substring match over each rule’s name and applicability text — it makes no judgement about which rules “apply” to a role. The caller supplies the term (a role name, an ARIA attribute, an element) and filters the results contextually. rulesByWCAG(scId) is the one mechanical mapping (straight from each rule’s front-matter).

Provenance and licensing

Data is derived from the act-rules.github.io repository, licensed under the W3C Document License (BSD-style, permits redistribution with attribution). See NOTICE. The loader code is MIT-licensed.

Related

• aria-query — WAI-ARIA roles, properties, element-role mappings
• apg-query — APG patterns
• wcag-query — WCAG 2.2 SCs + Techniques + Failures

Data versions

Each published version ↔ the upstream snapshot it was built from.

Version	Scraped	Upstream commit
0.1.1	2026-05-07	80e887e
0.1.0	2026-05-07	80e887e