Visual Verify

Run the acceptance pass that makes a rendered UI accepted rather than merely built. A UI is not accepted because its tests pass or its code reads correctly — it is accepted when it has been seen (captured and looked at), driven (a real user journey exercised against it), and measured (accessibility and performance scored against declared thresholds).

This is the written-down form of a standard the squad already applies: shared/capabilities/public/project/web-app.md and shared/capabilities/public/project/game-production.md both declare S4 as a required acceptance gate whose FAIL blocks the S6 ship step. This skill is the procedure for that gate.

When to use

• At S4 Verify in the S0–S7 project lifecycle (shared/modes/project.md) for any capability whose deliverable renders: web app, game production, or a visual surface inside another card.
• A UI change is being handed to review or ship and no one has looked at it.
• A packet asks for "visual verification", screenshots, or a Lighthouse/a11y score.

Skip it — as an explicit, recorded no-op — for backend, CLI, library, and other non-rendering deliverables. Record the skip and its reason; do not silently omit the gate.

Division of labour with visual-regression-baseline

These are not duplicates and must not be merged.

• visual-regression-baseline owns the diff: defining the capture set, freezing non-determinism, masking dynamic regions, comparing candidate against baseline under identical recorded conditions, and classifying each delta as intended or regression.
• This skill owns the gate: deciding the gate applies, obtaining a reachable target, running the capture / journey / audit passes, invoking the diff skill when a baseline exists, and producing a single accept-or-block verdict for S4.

When a baseline exists, step 4 below hands off to visual-regression-baseline rather than restating it.

Inputs

• A reachable target: a dev-server URL, a local build, or a running app instance. The packet or the S3 build handoff supplies it; this repo has no shared pipeline-state object to read it from, so if the target is absent the gate is blocked, not passed.
• The declared thresholds for the run. Defaults below are a starting point, not a standard — confirm against the packet or the capability card before treating a number as a gate.
• The baseline, if one exists, plus its recorded capture conditions.

Steps

1. Confirm the gate applies and the target is reachable. Establish the deliverable renders, then load the target once and confirm it serves. An unreachable target is a blocked gate — never a pass, and never a "capture what we can" partial.
2. Drive the key user journeys. Exercise the primary journeys end to end against the running app (playwright or chrome-devtools), not against a mock. A UI that renders but cannot be used has failed the gate. Record which journeys ran and their outcomes; a journey that was not run is reported as not run, never inferred from a passing unit test.

3. Capture the viewport matrix. Capture each canonical viewport, waiting for the page to settle before each capture:

   Viewport	Size	Stands in for
   Mobile portrait	320 × 568	Smallest realistic phone; where overflow appears first
   Tablet portrait	768 × 1024	The breakpoint most often skipped
   Laptop	1280 × 800	The default development viewport
   Desktop	1920 × 1080	Where fixed-width layouts strand content

   Adjust the matrix when the product's real breakpoints differ — but state the matrix you used.

4. Look at the captures, and diff if a baseline exists. Read every capture back through an image-read (view_image on the codex lane, or the lane's native image read). Capturing a screenshot is not seeing it — an unreviewed PNG is an artifact, not evidence, and this is the single most common way this gate is faked. Where a baseline exists, run visual-regression-baseline for the comparison and classification; where none exists, this run is capture-only — record the captures as candidates and state plainly that no diff was performed.
5. Run the accessibility and performance audit. Score the target and compare against the declared thresholds. Common defaults, to be confirmed rather than assumed: accessibility ≥ 90, performance ≥ 80. Pair the numeric score with wcag-conformance-audit — a passing aggregate score routinely hides specific conformance failures, because the score is an average and conformance is a conjunction.
6. Classify each failure before reporting it. Separate (a) a local fix the builder can make — contrast, a missing label, an unoptimized asset; (b) a design gap needing a decision; (c) a capability gap where a tool was unavailable. These route differently, and collapsing them into one "visual verify failed" line destroys the routing information.
7. Emit one verdict with its evidence. Accept only when the journeys pass, the captures were reviewed, the diff (if any) is classified, and the thresholds are met. Name what was not checked.

Tool surface — and what is actually verified about it

This skill names tools it needs; it does not assert they are live for you.

• playwright and chrome-devtools carry registry rows yes · subscription with lanes claude|codex|gemini. Grok is absent from that lane list — this gate cannot be run unaided on every lane, and a lane without browser tools must report a capability gap rather than approximate the pass.

• Browser contract — the governing rule is maintainer-private and withheld from this public distribution. An operator-settled contract governs every browser step of this gate: it carries the attach procedure, the persistent-profile path, the never-spawn prohibitions, and the one permitted exception (hermetic, unauthenticated acceptance testing may use a fresh isolated profile with its own user-data-dir, labelled as such in the report). The authoritative text lives in a maintainer-only file this distribution does not ship, so no public document restates it in full. What it requires operationally is what the paragraph below already spells out: attach to the operator's existing authenticated browser — the persistent Chrome profile with CDP on 127.0.0.1:9222, described in docs/install/daemon.md — rather than spawning a fresh one, and use the fresh-isolated-profile mode only for hermetic, unauthenticated testing, labelled as such.

  Local to this gate, and stated nowhere else: playwright and chrome-devtools observably spawn a fresh, isolated Chrome. The registry and shared/api-catalog.md describe that behaviour accurately — treat the description as a hazard to route around, not a sanctioned mode. A fresh profile has none of the operator's session, so a "pass" produced through one is a pass for a logged-out stranger, not for the operator's journey.

• The Lighthouse audit is a tool inside the chrome-devtools MCP, not a registry row of its own. Confirm it appears in your runtime's tool list before planning around it.
• No computer-use capture path is wired here. If the browser MCPs are unavailable, the honest outcome is a reported capability gap — not a degraded pass.

Per Hard Rule 9, a tool is available when a live call succeeds, never because a registry row or this document says so. Probe first; report capability_gap and use the packet's fallback if the probe fails.

Failure modes

• Screenshot-as-evidence — captures produced but never read back. The most common fake pass.
• Silent skip — the gate omitted for a rendering deliverable with no recorded reason.
• First-run diffing — reporting drift against a baseline that does not exist. First run is capture-only; say so.
• Score-only accessibility — an aggregate number treated as conformance.
• Threshold drift — the defaults above quoted as if they were the project's declared gate.
• Journey inference — "the tests pass, so the journeys work". The gate exists because that inference is what fails in practice.

Acceptance

• The gate was run or explicitly, reasonedly skipped; an unreachable target blocked it rather than passing it.
• Key user journeys were driven against the running app, and the ones that ran are named.
• Every viewport in the stated matrix was captured and read back through an image-read.
• Diffing either ran through visual-regression-baseline with each delta classified, or is reported absent because no baseline existed.
• Accessibility and performance were scored against thresholds sourced from the packet or capability card, and paired with a conformance check rather than standing alone.
• Every failure carries its classification; every unavailable tool is reported as a capability gap rather than silently dropped.