harden

harden is a command for coding agents from educlopez/ui-craft. It costs 75 tokens per session (952 once invoked), scanned A, original, MIT.

A production-readiness command for checking and improving a user interface beyond its normal success path. It covers loading, empty, error, partial-data, language, offline, and permission states.

In plain words
What is it for?
Use it before releasing a UI or when fixing missing loading states, empty screens, error messages, permission handling, and first-run guidance.
Why use it?
It finds confusing or missing behavior that only appears when data is slow, absent, incomplete, or unavailable.

Command

Part of the ui-craft plugin — 29 skills, 25 commands, 2 agents, 1 MCP server shipped together

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add commands/educlopez/ui-craft/harden
Clone the repo
git clone --depth 1 https://github.com/educlopez/ui-craft

Or install ui-craft, the plugin that ships this one along with the rest of its 29 skills, 25 commands, 2 agents, 1 MCP server.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for harden

README.md
[![agentmods](https://agentmods.dev/badge/commands/educlopez/ui-craft/harden.svg)](https://agentmods.dev/commands/educlopez/ui-craft/harden)
Your own site
<a href="https://agentmods.dev/commands/educlopez/ui-craft/harden"><img src="https://agentmods.dev/badge/commands/educlopez/ui-craft/harden.svg" alt="Measured on agentmods" height="20"></a>
Per session 75 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 952 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00075 $0.00952
Opus 5 $0.00037 $0.00476
Sonnet 5 $0.00015 $0.00190
Haiku 4.5 $0.00007 $0.00095

Measured 4d ago against content hash 79240ef78bda, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

harden scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 4d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

cli/assets/claude/commands/harden.md · 42 lines

What it actually says

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).

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 4d ago First seen · 42 lines · 75 tokens per session scan A 79240ef78bda

Subscribe to this mod's changes

harden is a command published in the GitHub repository educlopez/ui-craft (310 stars, last pushed yesterday), licensed MIT. It adds 75 tokens to every session and 952 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.