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 borhen68/SkillEngine --skill frontend-ui-engineeringgit clone --depth 1 https://github.com/borhen68/SkillEngineWrote 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/borhen68/skillengine/frontend-ui-engineering)<a href="https://agentmods.dev/skills/borhen68/skillengine/frontend-ui-engineering"><img src="https://agentmods.dev/badge/skills/borhen68/skillengine/frontend-ui-engineering/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/borhen68/skillengine/frontend-ui-engineering"><img src="https://agentmods.dev/badge/skills/borhen68/skillengine/frontend-ui-engineering.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 | $0.00048 | $0.02720 |
| Opus 5.5 | $0.00019 | $0.01088 |
| Sonnet 5.5 | $0.00010 | $0.00544 |
| Haiku 4.5 | $0.00005 | $0.00272 |
Grade A, and why
frontend-ui-engineering 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 1mo 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.
This is a copy
91% identical to frontend-ui-engineering — 47 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 348 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Frontend UI Engineering
Overview
Build production-quality user interfaces that are accessible, performant, and visually polished. The goal is UI that looks like it was built by a design-aware engineer at a top company — not like it was generated by an AI. This means real design system adherence, proper accessibility, thoughtful interaction patterns, and no generic "AI aesthetic."
When to Use
- Building new UI components or pages
- Modifying existing user-facing interfaces
- Implementing responsive layouts
- Adding interactivity or state management
- Fixing visual or UX issues
The UI Engineering Process
Building production UI follows a structured flow: architect the component, manage state correctly, adhere to the design system, ensure accessibility, handle responsiveness, and polish interactions. Skip any step and the result looks AI-generated instead of engineer-built.
Component Architecture
File Structure
Colocate everything related to a component:
src/components/
TaskList/
TaskList.tsx # Component implementation
TaskList.test.tsx # Tests
TaskList.stories.tsx # Storybook stories (if using)
use-task-list.ts # Custom hook (if complex state)
types.ts # Component-specific types (if needed)
Component Patterns
Prefer composition over configuration:
// Good: Composable
<Card>
<CardHeader>
<CardTitle>Tasks</CardTitle>
</CardHeader>
<CardBody>
<TaskList tasks={tasks} />
</CardBody>
</Card>
// Avoid: Over-configured
<Card
title="Tasks"
headerVariant="large"
bodyPadding="md"
content={<TaskList tasks={tasks} />}
/>
Keep components focused:
// Good: Does one thing
export function TaskItem({ task, onToggle, onDelete }: TaskItemProps) {
return (
<li className="flex items-center gap-3 p-3">
<Checkbox checked={task.done} onChange={() => onToggle(task.id)} />
<span className={task.done ? 'line-through text-muted' : ''}>{task.title}</span>
<Button variant="ghost" size="sm" onClick={() => onDelete(task.id)}>
<TrashIcon />
</Button>
</li>
);
}
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.
- 1mo ago First seen · 348 lines · 48 tokens per session scan A e6fa4ffbc761
frontend-ui-engineering is a skill published in the GitHub repository borhen68/SkillEngine (17 stars, last pushed 4mo ago), licensed MIT. It adds 48 tokens to every session and 2,720 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 91% identical to frontend-ui-engineering, differing in 47 lines, and is treated as a copy.
Other skills, from other repositories
frontend-ui-engineering
Builds production-quality, accessible, responsive user-facing UIs. Use when building or modifying interfaces and pages, creating components, implementing layouts, meeting WCAG accessibility requirements, managing state, or when the output needs to look and feel production-quality rather than AI-generated.
code-review-and-quality
A code-review guide for checking changes across correctness, readability, architecture, security, and performance before they are merged.
constraint-driven-development
A development method for writing a project's quality standards as a lasting, checkable contract. It can cover areas such as test coverage, security, performance, accessibility, and architecture.
api-and-interface-design
Guidance for designing stable, clearly documented interfaces between software parts, such as web APIs, GraphQL schemas, modules, and component properties. It covers defining the contract first, limiting accidental dependencies, and planning safe changes.
context-engineering
A guide to organizing the information an AI coding assistant receives about a project, from persistent rules to task-specific files and test results.
doubt-driven-development
A development practice that puts an independent, fresh-context challenge in front of important coding decisions.