| name | harden |
| description | Production-readiness pass — audits and implements the full non-happy-path matrix: loading skeletons, empty states, error messages, partial data, i18n, offline, permissions, and first-run guidance. Use when preparing a surface for production or when the user says "it crashes on empty data" / "there's no loading state" / "harden this". Invoke when the user asks for harden on their UI, or mentions 'harden' alongside design / UI / frontend work. |
Context: this sub-skill is one lens of the broader ui-craft skill. If the ui-craft skill is also installed, read its SKILL.md first for Discovery + Anti-Slop + Craft Test, then apply the specific lens below.
Harden the UI at $ARGUMENTS for production. Load the ui-craft skill.
Coverage matrix — check every key surface:
- Loading — skeletons match the final layout (no CLS on resolve), shown after ~200ms to avoid flash on fast responses. Never a generic centered spinner when a skeleton is possible.
- Empty — purposeful: one line explaining why it's empty + one clear primary action. Illustration optional, CTA mandatory.
- Error — inline, actionable. "Save failed. Try again / Copy error / Contact support" — never just "Something went wrong." Surface the what and the next step.
- Partial data —
— (em dash) for missing metrics, never N/A or null or 0 when the value is truly unknown.
- Long content — truncation with
title tooltip, text-overflow: ellipsis, container queries for constrained regions. Test with a 120-character name.
- i18n — no hardcoded strings, ~1.3× text expansion slack for German, narrower glyphs for CJK, RTL flip consideration for icons with direction.
- Offline / slow — optimistic UI with reconciliation on failure; skeleton persists past timeout with a "still loading…" affordance.
- Permission — what happens when the user lacks access: disabled vs hidden. Always surface a "why" (tooltip, inline helper) when disabled.
- Zero-state → first-run — inline hints beat 5-step tours. Guide within the surface, not over it.
Knob-agnostic — correctness is not tunable. Run the full matrix regardless of CRAFT_LEVEL / MOTION_INTENSITY / VISUAL_DENSITY.
Then run the archetype's coverage parts. The nine items above are cross-cutting; they do not know what kind of screen this is. Name the archetype (data table, settings, search, detail view, first-run, billing, pricing, docs page, checkout, onboarding, destructive confirm, invite/share) and pull its parts:
- MCP connected → call
ux_coverage with the archetype. It returns that archetype's parts and the reporting contract.
- No MCP → read the matching section of
references/coverage.md.
- No archetype matches → skip this step and say so in one line. Coverage is deliberately partial; an unlisted surface is not a failure.
Each part carries what present looks like, the ui-craft rule for building it, and what the user loses without it. Report the cost, not just the absence — "no export" is a status, "the user expects the 24 rows on screen and receives 10,000" is the reason it matters.
References to read: references/accessibility.md (keyboard + screen reader paths), references/copy.md (error and empty-state voice), references/motion.md Rendering Performance section (skeleton motion + reduced-motion).
Output: two sections, reported side by side and never combined.
- Hardening matrix — the 9 items above, each marked present / partial / missing.
- Coverage — the archetype's parts, each marked present / partial / missing / not-needed / unknown.
not-needed requires a stated reason; if you cannot say why it does not apply here, it is missing. unknown says whether more input would settle it.
No score, no count, no percentage on either section. "7 of 9" makes not-needed read as a failure and turns a hardening pass into a grade. Coverage never gates: it reports, and the build still ships.
Then edit the code to fix what's missing. Print the Review Format table showing fixes. End with a "still at risk" list for anything you couldn't safely auto-fix (requires backend, requires design decision, requires translation files).
Next step: /finalize — the pre-ship gate (rung 3).
