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Harden

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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.

Overview

Publishereduclopez
Repositoryui-craft
Skill nameharden
Stars
344
Forks
17
Bundled files
Instructions only
LicenseMIT
Links
  • Markdown instructions

    A SKILL.md file the model loads on demand, so it only costs tokens when a request actually matches.

  • Works with any LLM

    AI skills are plain Markdown, not provider-specific code, so this works with GPT, Claude, Gemini, Grok, or a local model.

  • Self-contained

    Everything the model needs lives in the instructions — no extra files to sync.

  • Open source

    Published by educlopez on GitHub. Read the source before you install it.

Installation

Install the Harden AI skill in TypingMind to use it with any LLM, or drop it into another agent that reads SKILL.md.

1

Install in TypingMind

TypingMind installs a skill straight from its GitHub folder — it reads SKILL.md, bundles the resource files, and stores the result locally.

  1. Open the app and go to Plugins → Skills.
  2. Choose "Install from GitHub".
  3. Paste the skill folder URL below and confirm.
  4. Enable the skill in any chat where you want it available.
Plugins → Skills → Add skill → From GitHub URL, then paste the folder URL and press Continue.
2

Install in another agent

Any agent that reads the Agent Skills format can use this skill — copy the folder into that agent's skills directory.

Claude Code — .claude/skills
git clone --depth 1 https://github.com/educlopez/ui-craft.git /tmp/ui-craft
mkdir -p .claude/skills
cp -r /tmp/ui-craft/cli/assets/codex/skills/harden .claude/skills/harden
Restart Claude Code after copying so it picks up the new skill.

Use it in TypingMind

Enable Harden in any TypingMind chat and the model takes it from there. Its name and description sit in the system prompt, and the moment a request matches, the model loads the full instructions itself — you never invoke it by hand, and it costs no tokens until it is actually used.

The model loads Harden on its own as soon as a request matches it.

Works with any AI model

AI skills are plain Markdown instructions rather than provider-specific code, so Harden is not tied to the model it was written for. Install it once in TypingMind and use it with GPT-5, Claude, Gemini, Grok, DeepSeek, Mistral, Llama, or a local model you run yourself — all on your own API keys.

  • Loaded only when it is needed

    The system prompt carries just the name and description. The instructions are fetched on the first matching request, so an idle skill costs nothing.

  • Switch models mid-chat

    Because the skill is instructions rather than code, changing model does not break it — the next model reads the same SKILL.md.

Skill instructions

This is the SKILL.md content the model loads. Read it before installing — a skill is instructions your model will follow.

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:

  1. 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.
  2. Empty — purposeful: one line explaining why it's empty + one clear primary action. Illustration optional, CTA mandatory.
  3. Error — inline, actionable. "Save failed. Try again / Copy error / Contact support" — never just "Something went wrong." Surface the what and the next step.
  4. Partial data (em dash) for missing metrics, never N/A or null or 0 when the value is truly unknown.
  5. Long content — truncation with title tooltip, text-overflow: ellipsis, container queries for constrained regions. Test with a 120-character name.
  6. i18n — no hardcoded strings, ~1.3× text expansion slack for German, narrower glyphs for CJK, RTL flip consideration for icons with direction.
  7. Offline / slow — optimistic UI with reconciliation on failure; skeleton persists past timeout with a "still loading…" affordance.
  8. Permission — what happens when the user lacks access: disabled vs hidden. Always surface a "why" (tooltip, inline helper) when disabled.
  9. 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.

  1. Hardening matrix — the 9 items above, each marked present / partial / missing.
  2. 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).

Frequently asked questions

What does the Harden AI skill do?

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.

Why use Harden on TypingMind?

Because you install it once and use it with any model. Harden is plain Markdown rather than provider-specific code, so the same skill runs on GPT-5, Claude, Gemini, Grok, or a local model — and you can switch model mid-chat without it breaking. TypingMind runs on your own API keys, so you pay providers directly instead of a per-seat subscription, and your skills and chats stay in your own storage.

How do I install Harden in TypingMind?

Open Plugins → Skills → Install from GitHub in TypingMind and paste https://github.com/educlopez/ui-craft/tree/main/cli/assets/codex/skills/harden. TypingMind reads its SKILL.md and installs it as a skill you can enable per chat.

Which AI models can use Harden?

Any model you connect in TypingMind. AI skills are plain Markdown instructions rather than provider-specific code, so GPT, Claude, Gemini, Grok, and local models can all load this skill when a request matches it.

How many AI models can I use with Harden?

As many as you like. As long as a model supports skills, you can use Harden with it — GPT, Claude, Gemini, Grok, DeepSeek, Mistral, Llama and more — all on TypingMind with your own API keys.

Is the Harden AI skill free?

Yes. It is published on GitHub by educlopez under the MIT license. You only pay your own AI provider for the tokens you use.

What are AI skills?

An AI skill is a reusable instruction bundle that teaches an AI model how to do one specific task. It follows the open Agent Skills format: a SKILL.md file with a name and description, plus any scripts, templates or reference files the model may need. The model reads the instructions only when your request matches the skill, so an installed skill costs nothing until it is used.

How are AI skills different from plugins or MCP servers?

A plugin or MCP server gives a model new tools to call — code that runs somewhere and returns a result. An AI skill gives the model knowledge and process instead: how to approach a task, which steps to follow, what good output looks like. Skills are plain Markdown, so they need no server, no API key and no runtime, and they work with any model.

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