About accessibility-inspect
accessibility-inspect is a semi-automated skill for assessing accessibility on running pages, aimed at teams checking keyboard use, focus, and state changes. It records evidence and untested checks but does not fix issues.
Key features
- 01Inspect keyboard behavior and focus
- 02Assess structure, state, and visual adaptation
- 03Grade findings by impact and evidence
- 04Track untested and human-review checks
Use cases
- 01Check keyboard behavior in custom widgets
- 02Assess form errors and state changes
- 03Hand off checks requiring assistive technology
Install
Copy the command and run it in a terminal.
npx skills add https:/ / github.com/ accesslint/ skills --skill accessibility-inspectAfter installing, type/accessibility-inspectin Claude Code to confirm it loaded.
Bundled filesreferences/checkpoints.md
Details
From the project READMEThis is the semi-automated manual tier of a WCAG assessment: the checks that need interaction (keyboard, focus, state changes, reflow) or human review (focus visibility, error recovery, reading order), which a static rule engine can't decide. Work against the running page; use source only to map a finding to file:line. Locate and assess — don't fix (that's accesslint:accessibility-fix). The automated tier is accesslint:accessibility-scan; accesslint:accessibility-audit runs both under WCAG-EM.
The shared rules — severity, the no-proxy boundary, high-risk patterns, conformance, grounding — are in ../shared/methodology.md. Read it when a call needs judgment. The rules that always apply are below.
Grading
Tag each finding with a severity (user impact) and an evidence basis (what you can support). Keep the two separate.
- ● Verified — deterministic and reproducible. Cite the selector, the interaction, and the observed a11y-tree or DOM fact. Without that proof it is not ●.
- ◐ Flagged — you have evidence, but the decision needs a person. Attach the evidence and your opinion; don't decide it yourself.
- ○ Human-required — needs assistive technology or lived experience. Hand it off; don't emulate it.
When unsure between two evidence grades, use the lower one. The icons show evidence basis by fill, not color.
A finding that stacks a deterministic fact on an interpretive call takes the lower grade. The machine-checkable half (e.g. no programmatic status in the a11y tree — a 1.3.1 fact) is ● evidence inside a ◐ finding; the interpretive conclusion (e.g. that color is the sole carrier of the meaning — 1.4.1) stays ◐. Citing the ● half does not upgrade the whole.
Severity (user impact, separate from evidence basis):
- Critical — blocks a core task, with no workaround.
- Serious — a major barrier; the task is possible but difficult.
- Moderate — noticeable friction; the task still completes.
- Minor — a small inefficiency or polish issue.
The ledger — a denominator, not a script
The checkpoint areas below are the run's denominator: every criterion in them ends the run in exactly one state, and the report says which.
- ● verified or ◐/○ flagged — you drove the check and have the evidence.
- N/A — the triggering feature isn't on the page (no form, no media, no drag UI). Decided from the snapshot; free.
- Not exercised — the feature is present but you didn't drive it. Reported as undetermined, never silently dropped, and never as a pass.
Not-exercised is a legitimate, honest outcome and it costs nothing. Drive only what the page's features and the engine's gaps demand; don't work through checkpoints to make the report look thorough. An "undetermined — not exercised" line and a driven-and-verified line differ in evidence, not in honesty.
Dedup before driving, not after: the engine (accessibility-scan) owns the statically-detectable criteria — name/label presence, lang, autocomplete, semantic markup, contrast of text on flat backgrounds. If a scan result set or engine-owned SC list was provided (as accessibility-audit does), never re-check those criteria; ledger them as engine-owned. Without one, read what you can from the initial snapshot rather than re-deriving what the engine would catch.
| Area | SCs | Trigger to drive |
|---|---|---|
| Keyboard & focus | 2.1.1, 2.1.2, 2.4.3, 2.4.7, 2.4.11 | Always — one batched walk (below) |
| Structure & semantics | 1.3.1, 1.3.2, 2.4.1, 2.4.6 | Always — read from the initial snapshot; no extra driving |
| Names, roles, states | 4.1.2, 2.5.3, 4.1.3 | Custom widgets / stateful controls present (static name presence is engine-owned) |
| Visual adaptation | 1.4.1, 1.4.4, 1.4.10, 1.4.12, 1.3.4, 2.3.3, 1.4.11 | Reflow/zoom on every page (one resize each); motion checks only if motion is present |
| Forms & errors | 3.3.1–3.3.3, 1.3.5, 3.3.7, 3.3.8 | A form is present (label/autocomplete presence is engine-owned) |
| Media & timing | 1.2.x, 2.2.1, 2.2.2 | <video>/<audio>, autoplay, or timeouts present |
| Pointer & target | 2.5.1, 2.5.7, 2.5.8 | Target size comes free from the batched walk; drag checks only if drag UI |
| Content & navigation | 3.1.1/2, 2.4.4, 3.2.3/4, 3.2.6 | lang and link purpose from the snapshot; cross-page consistency is accessibility-audit's (not exercised here) |
Per-checkpoint procedure and default grades: references/checkpoints.md. Read it when a triggered area needs its detailed steps, or when the user asks for a deep pass (--deep: drive every triggered area through its full procedure).
Evidence budget — cap spend by grade
Calibrated uncertainty must be cheaper than false certainty. The grade a finding can reach bounds the evidence worth gathering:
- ● — full proof, gathered once: selector, interaction, observed DOM or a11y-tree fact. Don't repeat an interaction you already recorded.
- ◐ — hard cap: one selector, one screenshot (only if the question is visual), your opinion, and what a person should confirm. Then stop. A ◐ is re-decided by a human whichever way you lean; more evidence doesn't upgrade it to ●, it just costs more.
- ○ — zero driving: name the functional ability, the assistive technology, and the flow you already exercised. Never drive the page to "strengthen" a ○.
Prerequisite: a browser to drive
This tier runs through a browser MCP: chrome-devtools (recommended), playwright, or puppeteer. If none is connected, run only the static checks, report the rest as ○ handoffs, and tell the user:
claude mcp add chrome-devtools npx -- -y chrome-devtools-mcp@latest
Target
$ARGUMENTS is a URL, an accesslint.config.json target name, or empty for the default target. --selector <css> scopes to a component; --wait-for <css> waits for async content.
navigate_page needs a URL, so resolve first:
- A URL: use it.
- A target name or empty: read
accesslint.config.json(and the gitignoredaccesslint.config.local.jsonoverlay) and resolve the name (ordefault) to itsurl; also take itswaitForandselector. - No config: ask for a URL, or suggest
npx @accesslint/cli init.
Then navigate to the URL and wait for the gate (--wait-for if given, otherwise the target's waitFor) before testing.
Driving efficiently
One snapshot, then scoped reads. Take one full snapshot after the wait gate; it is the basis for structure, names, roles, states, and the N/A decisions. After a state change, don't re-snapshot the page — read only the widget that changed, via evaluate_script scoped to its selector (or a snapshot of that subtree). A full-page re-snapshot per interaction is the single largest avoidable cost in this tier.
One batched keyboard walk. Traverse focus in a single evaluate_script call, not one press_key/snapshot cycle per stop: compute the tabbable sequence, focus() each element in order, and return compact JSON per stop — selector, role/name, document.activeElement confirmation, computed outline/box-shadow on :focus, bounding box (which settles 2.5.8 for free), and whether the element sits under a sticky/overlay rect (2.4.11). The walk is deterministic DOM fact, so its results are ●-citable.
The walk finds candidates; real key events confirm behavior. Scripted focus() doesn't run an app's keydown handlers, so operability (Enter/Space/arrows) and trap claims still need press_key — but only at the walk's suspects: composite widgets (roving tabindex, aria-activedescendant), elements whose handlers plausibly capture Tab/Esc, anything the walk couldn't reach. A ● keyboard-trap finding needs the real Tab/Esc presses at that widget; it doesn't need them at every widget on the page.
High-risk patterns
For drag-and-drop, rich-text editors, tree views, data grids, custom comboboxes or menus, carousels, and toast or live-region-heavy UIs, heuristic checks are unreliable. Name the APG pattern, verify what you can (●/◐), and hand off the rest as ○ with the assistive-technology steps to run. Use explain_rule for engine rules and the APG for widget contracts.
Report
Group findings by evidence basis; mark severity inline. Close the ledger at the top — every SC in the denominator lands in exactly one bucket — and keep it compact: counts, then bare SC numbers. Group not-exercised SCs by shared reason, one parenthetical clause per group, never a line per SC.
The report spends its words on failures, flags, and handoffs. A pass is its SC number in the ledger — not a paragraph: no "what passed" narration beyond at most one sentence, and no restating in the recommendations a fix already given on its finding.
# Manual inspection — <target> · semi-automated tier
Severity: <c> critical · <s> serious · <m> moderate Basis: ● <v> · ◐ <f> · ○ <h>
Ledger: pass ● <SCs> · fail ● <SCs> · flagged ◐/○ <SCs> · engine-owned <SCs> · N/A <SCs>
not exercised → undetermined: <SCs (shared reason)> · <SCs (shared reason)>
## ● Verified
- [serious] Keyboard trap in date picker — SC 2.1.2
where: div.datepicker[role=dialog] repro: Tab into grid, focus never exits via Tab or Esc
fix: <mechanical> | NEEDS HUMAN
## ◐ Flagged
- [moderate] Focus indicator may be too faint — SC 2.4.7
where: button.ghost evidence: focus-ghost.png; outline = 1px rgba(0,0,0,.2)
opinion: likely fails 3:1 non-text contrast — confirm visually
## ○ Human-required
- Live-region announcement on add-to-cart — SC 4.1.3
aria-live="polite" present (●); actual NVDA/JAWS/VoiceOver output unverified
needs: screen-reader users (blind / low-vision, per Section 508 FPC)
flow: add-to-cart → toast (exercised above)
Ground each entry by selector and visible text. Add file:line (symbol) only when accessibility-scan's source maps provide it; don't guess. Each ○ entry is a handoff: the functional ability and assistive technology needed, plus the flow you exercised.
Notes
- The a11y tree shows machine state, not what a screen reader announces.
aria-livebeing present does not mean it announces. - Browser zoom isn't exposed; CSS-zoom approximations are ◐.
- Wait for async content before the initial snapshot; after that, prefer selector-scoped reads over re-snapshots.
- Composing the tiers (dedup against
accessibility-scan, one shared browser) isaccessibility-audit's job. On its own, this skill reports what its checks find — and its ledger says what they didn't.