Accessibility Audit

Architecture

This skill operates as a single layer. It reads the project environment, runs automated accessibility tools, maps findings to compliance standards, and produces output in a configurable format. No external skill dependency is required.

Store project-specific audit state in the target workspace, not in the installed skill directory. Default path:

.a11y-audit/PROJECT_CONTEXT.md

at the workspace root. When that file exists, use it for project-specific configuration: output mode, additional compliance standards, issue tracker settings, route lists, color palettes, and cross-references to existing documentation. When absent, use WCAG 2.1 AA as the sole standard,

markdown

as the output mode, and generic defaults for everything else.

Use

references/project-context-template.md

as the canonical schema for that file, including minimal and

markdown+issues

examples.

Prefer bundled helpers over ad hoc generation when they fit:

scripts/bootstrap-context.js

creates a workspace-local

.a11y-audit/PROJECT_CONTEXT.md

from simple inputs.

```
scripts/scan.js
```
runs reusable axe-based scans and records optional Lighthouse execution intent. Use
```
--summary
```
to reduce output size (keeps full violation detail, strips node data from passes/inapplicable).
```
scripts/report.js
```
generates the markdown report and JSON data file from scan.js output. Handles WCAG compliance matrix, violation aggregation, and color-contrast detail extraction deterministically.
```
scripts/discover.js
```
identifies template groups on large sites and selects representative pages for scanning. Reads sitemap.xml first, falls back to HTML navigation crawl. Outputs a scan plan with template groups and a ready-to-use URL list for scan.js.

Dependencies

scan.js requires

axe-core

and

puppeteer

. It resolves these in order:

Skill-local
```
deps/
```
directory (sibling to
```
scripts/
```
)
Target project
```
node_modules/
```
(and common workspace subdirs)
Global npm modules

If not found anywhere, scan.js auto-installs both packages to the skill-local

deps/

directory. This means the skill works against any project without requiring the target to have accessibility tooling installed. The

deps/

directory is gitignored.

Platform-Specific References

If running in Claude Code, read
```
references/claude-code.md
```
for
```
.claude/launch.json
```
handling and Preview tool usage.
If running in Codex, read
```
references/codex.md
```
for workspace-local state handling and execution assumptions.

references/output-contract.md

and

references/output-schema.json

are encoded in

scripts/report.js

. Read them only when modifying the report script.

Read

references/issue-trackers.md

only when

output_mode

markdown+issues

If the user wants to operationalize recurring audits in CI, start from
```
assets/ci/github-actions/accessibility-audit.yml
```
.
Prefer
```
scripts/plan-issues.js
```
before live ticket creation when you need a safe review and deduplication pass.

The skill does not modify source code. It is an auditor, not a fixer. Findings are reported with remediation guidance; the user decides what to act on.

Output Modes

The skill supports three output modes, configured via the

output_mode

field in

.a11y-audit/PROJECT_CONTEXT.md

Mode	Output	Use Case
`markdown`	Markdown report only	Human review, documentation
`markdown+json`	Markdown report + JSON data file	CI integration, dashboards, trend tracking
`markdown+issues`	Markdown report + issue tracker tickets	Active remediation workflow

On first run, if no

output_mode

is set in

.a11y-audit/PROJECT_CONTEXT.md

, ask the user which mode they prefer and persist their choice by appending an

## Output Configuration

section to that file. If no context file exists, create it at the default path following

references/project-context-template.md

. Prefer

scripts/bootstrap-context.js

for first-run context creation when a simple generated file is sufficient.

The

markdown+json

mode writes a companion file alongside the report:

audit-YYYY-MM-DD.json

containing the raw axe-core results, Lighthouse scores, and the compliance matrix as structured data. This file is machine-readable and can be consumed by CI pipelines, dashboards, or trend-tracking tools.

The

markdown+issues

mode requires additional configuration in the context file (see Phase 6).

Pipeline

An accessibility audit moves through six phases. Each phase produces data the next phase consumes. Phases 1-4 always run. Phase 5 produces output based on the configured output mode. Phase 6 runs only in

markdown+issues

mode and requires explicit user confirmation.

The user can request a partial run. Common patterns:

"Quick scan": Phases 1-2 only, results summarized in conversation
"Full audit": Phases 1-5, output per configured mode
"Audit with issues": Phases 1-6, report plus tracker tickets

Phase 1 -- Environment Discovery

Purpose: Understand the project before scanning.

Read

.a11y-audit/PROJECT_CONTEXT.md

if it exists (standards, routes, output mode, labels). If absent, create it via

scripts/bootstrap-context.js

or from

references/project-context-template.md

Read
```
package.json
```
for tech stack, existing a11y tooling, and available browser automation (
```
puppeteer
```
/
```
playwright
```
).
Build a scannable URL list from router config or HTML file glob. For sites with many pages (>15 routes), prefer
```
scripts/discover.js
```
to classify pages into template groups and select representatives. Review the scan plan with the user before proceeding to Phase 2.
Confirm a dev server is reachable. Check
```
.claude/launch.json
```
and platform-specific references for launch hints. If the app starts on a different URL than expected, switch to the live URL, record the mismatch, and update the context file.
Ask before installing any missing dependencies.

Output: Structured summary reported to the user before proceeding.

Phase 2 -- Automated Scanning

Purpose: Run automated accessibility checks against live pages.

Prerequisite: A running dev server (or production URL provided by the user).

axe-core Scanning

Prefer the bundled

scripts/scan.js

before writing a throwaway scan script. Use an ad hoc script only when the workspace needs behavior that the bundled script does not yet support.

The reusable scanner should:

Imports
```
puppeteer
```
and
```
axe-core
```
Launches a headless browser
For each target URL: a. Navigates to the page b. Waits for network idle (
```
waitUntil: 'networkidle0'
```
) c. Injects axe-core: reads the axe-core source file from
```
node_modules/axe-core/axe.min.js
```
and injects it via
```
page.evaluate()
```
d. Runs the audit:
```
page.evaluate(() => axe.run())
```
e. Collects the results JSON
Closes the browser
Writes raw results to JSON

Example invocation:

bash

node a11y-audit/scripts/scan.js \
  --root . \
  --urls http://127.0.0.1:3000/,http://127.0.0.1:3000/about \
  --output /tmp/a11y-scan.json \
  --summary

Adapt to the project. If dependencies live in a frontend subdirectory, point

--root

at the workspace root; the bundled script already checks common frontend paths. If that still fails, fall back to an ad hoc script or run from the frontend directory directly.

Common mistake: Do not use

require()

in an ES module project. Check

package.json

for

"type": "module"

. If present, use

import

syntax and the

__dirname

workaround in any ad hoc script. If absent,

require()

is fine.

Playwright alternative: If the project uses Playwright instead of Puppeteer, adapt the script: replace

puppeteer.launch()

with

chromium.launch()

, use

page.goto()

the same way, and inject axe-core via

page.evaluate()

. The axe-core injection pattern is identical. Use whichever browser automation library the project already has installed.

Lighthouse Scanning

Run Lighthouse CLI against each target URL:

bash

npx lighthouse <url> \
  --output=json \
  --output-path=stdout \
  --only-categories=accessibility \
  --chrome-flags="--headless --no-sandbox" \
  --quiet

Parse the JSON output. Extract:

```
categories.accessibility.score
```
(0-1, multiply by 100)
```
audits
```
where
```
score !== 1
```
(failed or partial audits)
Each audit's
```
description
```
and
```
details.items
```

If Lighthouse is unavailable or fails (common in CI environments), skip it and note the gap in the report. In the executive summary and methodology, explicitly say whether Lighthouse was skipped because the CLI was missing, Chrome launch failed, or another runtime error occurred. axe-core results alone are sufficient for a valid audit.

Scope Control

Default: scan routes discovered in Phase 1
If a discover.js scan plan exists, use its
```
scanList
```
for
```
--urls
```
. The report methodology will record the sampling strategy.
If more than 10 routes exist and no discover plan is available, ask the user which to scan or whether to scan all
The user can provide a specific URL list to override discovery
For SPAs: navigate via the router, not by reloading the page (some routes may not work as direct URLs)

Result Structure

For each page, collect:

```
url
```
: the scanned URL
```
violations
```
: array of axe violations, each with
```
id
```
,
```
impact
```
(critical/serious/moderate/minor),
```
description
```
,
```
help
```
,
```
helpUrl
```
,
```
tags
```
(WCAG criteria),
```
nodes
```
(affected elements with selectors)
```
passes
```
: count of passing rules
```
incomplete
```
: rules that could not be fully evaluated
```
lighthouseScore
```
: 0-100 (if available)
```
lighthouseAudits
```
: failed audit details (if available)

Phase 3 -- Compliance Mapping

Purpose: Map automated findings to WCAG 2.1 AA success criteria and any project-specific standards.

scripts/report.js

handles the compliance matrix deterministically. It hardcodes all 50 WCAG 2.1 Level A and AA criteria, maps axe tags to success criteria, and produces the matrix as part of its markdown and JSON output. You do not need to build the matrix manually.

.a11y-audit/PROJECT_CONTEXT.md

specifies additional standards (e.g., CAN-ASC-6.2), build a secondary mapping. Cross-reference automated findings where the standard maps to WCAG criteria. For requirements that go beyond WCAG (equity, organizational processes, transparency), note them as manual review items referencing the project's existing conformance documentation.

Phase 4 -- Manual Check Guidance

Purpose: Generate targeted checklists for what automation cannot verify, prioritized by the automated findings.

For each WCAG criterion marked "Manual" in the Phase 3 matrix, generate a testing item. Organize by testing method: Keyboard Navigation, Screen Reader, Visual Inspection, Cognitive, and Timing/Motion.

Dynamic prioritization: Do not produce a static checklist. Use the Phase 2 results to focus manual effort:

If axe found color-contrast violations, prioritize visual inspection items (SC 1.4.1, 1.4.11, 1.4.10, 1.4.12, 1.4.13)
If axe found ARIA or landmark violations, prioritize screen reader items (SC 1.3.1, 4.1.3, 3.3.1, 3.3.2)
If axe found heading or structure violations, prioritize keyboard navigation items (SC 2.4.3, 2.4.7, 2.1.1)
If no form-related violations were found, deprioritize form testing (SC 3.3.3, 3.3.4) with a note that automated checks passed
Always include timing items (SC 2.2.1, 2.2.2, 2.3.1) since these cannot be automated at all

Each checklist item specifies: the WCAG criterion, what to test, how to test it, and which pages to focus on (pages where automated issues were found get priority).

.a11y-audit/PROJECT_CONTEXT.md

references an existing testing guide, cross-link to it rather than duplicating procedures.

Phase 5 -- Output Generation

Purpose: Produce output based on the configured output mode.

Run

scripts/report.js

to generate the markdown report and JSON data file from the Phase 2 scan output:

bash

node a11y-audit/scripts/report.js \
  --input /tmp/a11y-scan.json \
  --output-dir docs/accessibility/audits \
  --project-name "Project Name" \
  --runtime-url http://127.0.0.1:3000 \
  --expected-url http://localhost:3000 \
  --discover /tmp/a11y-discover.json

Pass

--discover

when a discover.js scan plan was used. This adds a Sampling Strategy subsection to the report methodology documenting template groups and coverage ratio.

Pass

--previous <prior-audit.json>

to generate a Delta from Previous Audit section showing fixed rules, new rules, changed instance counts, and net progress.

The script produces

audit-YYYY-MM-DD.md

and

audit-YYYY-MM-DD.json

following the contracts in

references/output-contract.md

and

references/output-schema.json

. You do not need to read those reference files unless modifying the report script itself.

After running report.js, review its output and fill in the Manual Testing Recommendations section with the Phase 4 guidance (report.js leaves a placeholder for this since it requires reasoning about the specific findings pattern).

.a11y-audit/PROJECT_CONTEXT.md

can override the output path.

If the user wants a recurring or on-demand CI job, adapt

assets/ci/github-actions/accessibility-audit.yml

to the target workspace instead of inventing a workflow from scratch.

Phase 6 -- Issue Creation (conditional)

Purpose: Create issue tracker tickets for findings. Runs only when the output mode is

markdown+issues

This phase requires explicit user confirmation. Before creating any tickets, show the user how many will be created, at what priority levels, and ask for approval.

Read

references/issue-trackers.md

for tracker configuration, deduplication, priority mapping, and ticket structure. Use the tracker settings from

.a11y-audit/PROJECT_CONTEXT.md

Verification

After completing an audit, verify these quality checks:

axe results valid: Compare violation count against a manual axe DevTools browser extension run on the same page. Counts should match within tolerance (axe versions may differ slightly).
Lighthouse score consistent: Compare against a manual Chrome DevTools Lighthouse run when Lighthouse was actually executed. Should be within 5 points.
WCAG matrix complete: All 50 AA criteria appear in the compliance matrix. No criterion is missing.

Treat the matrix as evidence-oriented status reporting. Do not frame it as proof of full conformance, because many WCAG criteria remain manual even in a strong automated run.
Report structure: All required sections present. Tables render correctly in a markdown viewer.
JSON validity (
```
markdown+json
```
mode): JSON file parses without error. Violation counts match the markdown report.
Issue deduplication (
```
markdown+issues
```
mode): Run the skill twice. The second run should create zero duplicate tickets.
Output mode persistence: After first run, verify the output mode is saved to
```
.a11y-audit/PROJECT_CONTEXT.md
```
and used automatically on next run.
Runtime URL reconciliation: If the app started on a different local URL than expected, verify the report records the mismatch and the context file reflects the actual working
```
base_url
```
.

What This Skill Does NOT Do

Visual regression testing: does not compare screenshots between runs. Use Percy, Chromatic, or BackstopJS for that.
PDF accessibility: does not audit PDF documents for tagged structure, reading order, or alternative text.
Real device/AT testing: runs in headless Chromium only. Cannot test on real iOS/Android or with real screen readers. Phase 4 generates manual checklists for this.
Code fixes: reports findings but does not modify source code.
VPAT generation: does not produce Voluntary Product Accessibility Templates (specific legal format).
Continuous monitoring: runs on demand, not as a CI pipeline. The
```
markdown+json
```
output mode provides structured data for building CI integrations, but the skill itself does not run in CI.
Third-party auditing: only audits the project's own frontend, not embedded third-party services.

a11y-audit

NPX Install

Tags

SKILL.md Content

Accessibility Audit

Architecture

Dependencies

Platform-Specific References

Output Modes

Pipeline

Phase 1 -- Environment Discovery

Phase 2 -- Automated Scanning

axe-core Scanning

Lighthouse Scanning

Scope Control

Result Structure

Phase 3 -- Compliance Mapping

Phase 4 -- Manual Check Guidance

Phase 5 -- Output Generation

Phase 6 -- Issue Creation (conditional)

Verification

What This Skill Does NOT Do