Agent skill · software engineering · aiskillstore
harden
Improve interface resilience through better error handling, i18n support, text overflow handling, and edge case management. Makes interfaces robust and production-ready.
Why this skill is useful
Provides specific CSS and JavaScript patterns for robust error handling and internationalization that the AI wouldn't reliably generate on its own.
What it needs
About 5k tokens when loaded. Last updated 2026-08-07. 405 stars on the source repository.
What this skill does
Strengthen interfaces against edge cases, errors, internationalization issues, and real-world usage scenarios that break idealized designs. Assess Hardening Needs Identify weaknesses and edge cases: 1. Test with extreme inputs: Very long text (names, descriptions, titles) Very short text (empty, single character) Special characters (emoji, RTL text, accents) Large numbers (millions, billions) Many items (1000+ list items, 50+ options) No data (empty states) 2. Test error scenarios: Network failures (offline, slow, timeout) API errors (400, 401, 403, 404, 500) Validation errors Permission errors Rate limiting Concurrent operations 3. Test internationalization: Long translations (German is often 30% longer than English) RTL languages (Arabic, Hebrew) Character sets (Chinese, Japanese, Korean, emoji) Date/time formats Number formats (1,000 vs 1.000) Currency symbols CRITICAL: Designs that only work with perfect data aren't production-ready. Harden against reality. Hardening Dimensions Systematically improve resilience: Text Overflow & Wrapping Long text handling: Flex/Grid overflow: Responsive text sizing: Use clamp() for fluid typography Set minimum readable sizes (14px on mobile) Test text scaling (zoom to 200%) Ensure containers expand with text Internationalization (i18n) Text expansion: Add 30-40% space budget for translations Use flexbox/grid that adapts to content Test with longest language (usually German) Avoid fixed widths on text containers RTL (Right-to-Left) support: Character set support: Use UTF-8 encoding everywhere Test with Chinese/Japanese/Korean (CJK) characters Test with emoji (they can be 2-4 bytes) Handle different scripts (Latin, Cyrillic, Arabic, etc.) Date/Time formatting: Pluralization: Error Handling Network errors: Show clear error messages Provide retry button Explain what happened Offer offline mode (if applicable) Handle timeout scenarios Form validation errors: Inline errors near fields Clear, specific messages Suggest corrections Don't …
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills aiskillstore/harden