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.
npx skills add KyaniteLabs/checkyourself --skill 02-frontend-experiencegit clone --depth 1 https://github.com/KyaniteLabs/checkyourselfWrote 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.
[](https://agentmods.dev/skills/kyanitelabs/checkyourself/02-frontend-experience)<a href="https://agentmods.dev/skills/kyanitelabs/checkyourself/02-frontend-experience"><img src="https://agentmods.dev/badge/skills/kyanitelabs/checkyourself/02-frontend-experience/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/kyanitelabs/checkyourself/02-frontend-experience"><img src="https://agentmods.dev/badge/skills/kyanitelabs/checkyourself/02-frontend-experience.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00081 | $0.01196 |
| Opus 5 | $0.00041 | $0.00598 |
| Sonnet 5 | $0.00016 | $0.00239 |
| Haiku 4.5 | $0.00008 | $0.00120 |
Grade A, and why
frontend-experience 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 9d 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.
How it starts
The opening of the file, as written. The whole thing — 113 lines — stays where its author put it; the contents beside it link to each section on GitHub.
frontend-experience
Build and harden user interfaces for accessibility, performance, resilience, and secure client behavior.
Operating contract
Act as a production hardening specialist for 02 Frontend. Use model-agnostic reasoning: no instruction, output, or workflow in this capability depends on a particular model vendor or agent runtime. Prefer deterministic evidence over persuasive prose. When evidence is missing, name the assumption and make it visible in the output.
When to activate
Use this capability for UI architecture, frontend performance, accessibility, routing guards, forms, client state, design-system integration, browser security boundaries, and user-facing AI interfaces. Trigger on React, Vue, Angular, Svelte, components, UI, a11y, WCAG, Core Web Vitals, forms, routing, lazy loading, bundle size, hydration, or client errors.
Inputs to request or inspect
- designs
- component code
- routes
- state model
- API contracts
- browser errors
- performance traces
Work protocol
- Map UI work into pages, sections, widgets, primitives, layouts, hooks, and shared state boundaries.
- Prefer typed contracts at API boundaries and schema-validated form input before mutation calls.
- Design for loading, empty, error, offline, partial-data, and permission-denied states before styling polish.
- Enforce accessibility through semantic HTML, keyboard paths, focus management, labels, contrast, and screen-reader behavior.
- Budget performance by route: initial payload, lazy-loaded chunks, expensive renders, image strategy, hydration cost, and network waterfalls.
- Treat the browser as untrusted. Never rely on client-side route guards as the only authorization control.
- For AI/RAG interfaces, expose citations, uncertainty, feedback controls, and safe failure states.
Required output format
Return a concise report with these sections unless the user requested a concrete file or code diff:
- Scope interpreted — what is in and out.
- Findings / decisions — ordered by production risk, not by discovery order.
- Recommended actions — owner-ready tasks with priority and rationale.
- Verification evidence — tests, scans, contracts, telemetry, commands, or review steps required.
- Residual risk / assumptions — what remains uncertain and how to resolve it.
- Hand-offs — other capabilities that should review the work.
What ships with it
1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 9d ago First seen · 113 lines · 81 tokens per session scan A 7b39ef5e7960
frontend-experience is a skill published in the GitHub repository KyaniteLabs/checkyourself (5 stars, last pushed 2d ago), licensed Apache-2.0. It adds 81 tokens to every session and 1,196 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 2026-08-31.
Other skills, from other repositories
frontend-design
Visual design and aesthetic direction for frontend interfaces. Use when building web pages, landing pages, dashboards, Next.js server components, or applications where visual identity matters. For React patterns and testing, use react-frontend.
von-restorff-effect
Apply the Von Restorff Effect — the element that differs from its neighbours is the one remembered. Use when a single action must dominate. For overall ordering rather than single-element emphasis, use visual-hierarchy.
handoff-spec
Write the implementation handoff — measurements, behaviours, assets, states, and edge cases. Use when engineering picks up the work. For verifying the result afterwards use design-qa-checklist; for reusable library components use component-spec (design-systems).
animation-principles
Apply animation principles — easing, staging, follow-through — to one specific UI motion. Use when tuning how an animation feels. For product-wide duration and easing tokens use motion-system (design-systems); for a full interaction spec use micro-interaction-spec.
dark-mode-design
Adapt an existing palette to dark mode — surface elevation, contrast rebalancing, and desaturation rules. Use when you already have a light palette to translate. For building the base palette first, use color-system.
readable-measure
Set line length and measure for comfortable reading across type sizes and breakpoints. Use when tuning body text. Covers measure only — for the full size and weight scale, use typography-scale.