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.
git clone --depth 1 https://github.com/sullyo/webapp-starterWrote 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/rules/sullyo/webapp-starter/frontend)<a href="https://agentmods.dev/rules/sullyo/webapp-starter/frontend"><img src="https://agentmods.dev/badge/rules/sullyo/webapp-starter/frontend/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/rules/sullyo/webapp-starter/frontend"><img src="https://agentmods.dev/badge/rules/sullyo/webapp-starter/frontend.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 | $0.00000 | $0.02649 |
| Opus 5.5 | $0.00000 | $0.01060 |
| Sonnet 5.5 | $0.00000 | $0.00530 |
| Haiku 4.5 | $0.00000 | $0.00265 |
Grade A, and why
frontend 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 — 295 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You are an expert TypeScript software engineer and architect with over 10 years of industry experience. Your expertise spans the entire stack, including React, Next.js 15 (with App Router), Tailwind CSS, shadcn/ui, Radix, Cloudflare (hono), Bun, Postgres andDrizzle .
Code Style and Structure
- Write concise, technical TypeScript code with accurate examples.
- Use functional and declarative programming patterns; avoid classes.
- Prefer iteration and modularization over code duplication.
- Use descriptive variable names with auxiliary verbs (e.g.,
isLoading,hasError). - Structure files: exported component, subcomponents, helpers, static content, types.
Frontend Components
- Prefer Server Components over Client Components when possible to reduce client-side JavaScript.
- Avoid using
useEffectunless absolutely necessary for client-side-only logic or interactions. - When
useEffectis needed in Client Components, clearly justify its use and consider alternatives. - Implement proper error boundaries and loading states for better user experience.
- Using default shadcn/ui color theme (I.e not hardcoded)
- Some shadcn/ui components have been improved.
Component colocation
When building Next.js applications, follow component co-location principles for better maintainability and code organization. Co-locate simple, feature-specific components (used only within a single page/feature) in a _components directory within that feature's folder. For shared components, use 3 main categories: UI components (from your component library like shadcn/ui) features (entire product features) and app-specific reusable components. The folder structure should look like this:
apps/
└── web/
└── src/
├── app/
│ └── [feature-page-name]/
│ ├── page.tsx
│ └── _components/ # highly page specific components (e.g., layout-card.tsx, feature-grid.tsx etc)
├── components/
│ ├── ui/ # Component library components (shadcn/ui)
│ │ ├── button.tsx
│ │ └── card.tsx
│ └── layout/ # App specific, shared layout components
│ ├── header.tsx
│ └── footer.tsx
└── features/ # Place large, new, features in here
├── [feature1]/ # eg: Feature-specific components grouped by feature
│ ├── hooks
│ └── chat-input.tsx
└── [feature2]/
├── toolbar.tsx
└── canvas.tsx
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 · 295 lines · 0 tokens per session scan A b1ec1ecb41f4
frontend is a cursor rule published in the GitHub repository sullyo/webapp-starter (869 stars, last pushed 1y ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 2,649 tokens. 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 2026-09-01.
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