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 quangpl/browser-extension-skills --skill extension-uigit clone --depth 1 https://github.com/quangpl/browser-extension-skillsWrote 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/quangpl/browser-extension-skills/extension-ui)<a href="https://agentmods.dev/skills/quangpl/browser-extension-skills/extension-ui"><img src="https://agentmods.dev/badge/skills/quangpl/browser-extension-skills/extension-ui/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/quangpl/browser-extension-skills/extension-ui"><img src="https://agentmods.dev/badge/skills/quangpl/browser-extension-skills/extension-ui.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 | $0.00037 | $0.01211 |
| Opus 5.5 | $0.00015 | $0.00484 |
| Sonnet 5.5 | $0.00007 | $0.00242 |
| Haiku 4.5 | $0.00004 | $0.00121 |
Grade A, and why
extension-ui 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.
How it starts
The opening of the file, as written. The whole thing — 158 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Extension UI
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Build professional, polished Chrome extension interfaces. Do NOT just explain — execute the workflow.
Workflow (Execute This)
Step 1: Detect context
- Check framework:
package.json→ React / Vue / Svelte / Vanilla - Check existing UI files: popup, sidepanel, options, content scripts
- Check if Tailwind / shadcn / DaisyUI already configured
- Identify extension type: popup-only, sidepanel, full options page
Step 2: Analyze existing UI
If UI files exist:
- Read component files for layout, spacing, color usage
- Check for dark mode support (
prefers-color-schemeorclass="dark") - Check accessibility: semantic HTML, aria-labels, focus management
- Check for Chrome design language alignment
Report findings: what's good, what needs improvement, priority fixes.
Step 3: Recommend UI stack
| Framework | Recommended Stack |
|---|---|
| React | shadcn/ui + Tailwind (best component quality) |
| React (minimal) | Tailwind only + custom compact theme |
| Vue | DaisyUI + Tailwind |
| Svelte | Tailwind + svelte-headlessui |
| Vanilla | Custom CSS with CSS variables |
Step 4: Implement improvements
Apply fixes in priority order:
- Dark mode support (critical — many users use dark mode)
- Proper sizing constraints (see
references/extension-ui-constraints.md) - Typography and spacing for small surfaces
- Accessibility fixes (keyboard nav, aria, focus)
- Loading/error/empty states
- Animations (subtle, fast, purposeful)
Extension UI Constraints (Summary)
| Surface | Size | Key Constraints |
|---|---|---|
| Popup | max 800x600px | Closes on outside click, no resize |
| Sidepanel | 320-400px wide | Full height, persistent |
| Options page | Full tab | Standard web page |
| Content script UI | Injected | CSS isolation via shadow DOM |
What ships with it
4 files 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.
- 1mo ago Changed · +17 lines da224c5d5a81
- 1mo ago First seen · 141 lines · 37 tokens per session scan A 04267129f393
extension-ui is a skill published in the GitHub repository quangpl/browser-extension-skills (63 stars, last pushed 24d ago), licensed MIT. It adds 37 tokens to every session and 1,211 once invoked, about $0.0001 per session on Opus 5.5. 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.
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