mcpbeat

Harden

educlopez/harden

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.

768 tokens
context cost
the whole folder, loaded on every use
1
files
instructions only
0
copies elsewhere
how many repositories repackaged it
237
stars on the repo
on the repository, not the skill itself

Install

one command, takes just this skill from the repository 
npx skills add https://github.com/educlopez/ui-craft --skill harden

The instruction itself

as written by the author

<!-- HARNESS MIRROR — do not edit here. Canonical source: skills/ or commands/. After editing source, copy into cli/assets/<harness>/ and repo-root harness mirrors. -->

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.

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: a per-surface checklist marking each of the 9 items as present / missing / partial. 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).

How to use it

Copy the folder

Take educlopez/harden from the repository into ~/.claude/skills for personal use, or into .claude/skills inside a project.

Check the name does not clash

The agent identifies a skill by the name field in its header. Two skills with the same name cannot sit side by side — one of them will be ignored.