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 agentmods add rules/johnpolacek/vibecode.party.starter/402-shadcngit clone --depth 1 https://github.com/johnpolacek/vibecode.party.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/johnpolacek/vibecode.party.starter/402-shadcn)<a href="https://agentmods.dev/rules/johnpolacek/vibecode.party.starter/402-shadcn"><img src="https://agentmods.dev/badge/rules/johnpolacek/vibecode.party.starter/402-shadcn.svg" alt="Measured on agentmods" 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 | $0.00738 |
| Opus 5 | $0.00000 | $0.00369 |
| Sonnet 5 | $0.00000 | $0.00148 |
| Haiku 4.5 | $0.00000 | $0.00074 |
Grade A, and why
402-shadcn 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 6d 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 — 116 lines — stays where its author put it; the contents beside it link to each section on GitHub.
shadcn Component Usage Guidelines
Description
Prefer to use shadcn/ui components rather creating your own.
This rule documents our standard patterns for using shadcn/ui components and finding additional components built on top of shadcn.
Installation & Setup
Installing Components
Always use the shadcn CLI to add new components. This ensures proper installation with all dependencies:
# Install a new component
pnpm dlx shadcn@latest add <component-name>
# Examples:
pnpm dlx shadcn@latest add button
pnpm dlx shadcn@latest add alert-dialog
Core Components
Using shadcn/ui
We use shadcn/ui as our primary component library. All basic UI components should come from shadcn/ui first.
// Example of importing and using shadcn components
import { Button } from "@/components/ui/button"
import { Card } from "@/components/ui/card"
import { Input } from "@/components/ui/input"
// Use them in your components
<Card>
<Input placeholder="Enter text" />
<Button>Submit</Button>
</Card>
Extended Components
Finding Additional Components
When we need more specialized components that aren't in the core shadcn/ui library:
- First check the awesome-shadcn-ui repository for existing solutions
- Look for components that:
- Are well-maintained
- Follow shadcn/ui patterns
- Have TypeScript support
- Are compatible with our tech stack
Popular Extended Components
Some recommended extended components from the ecosystem:
- For date/time:
date-time-picker-shadcnordate-range-picker-for-shadcn - For forms:
auto-formfor zod-based form generation - For search:
async-selectwith debounce search - For calendars:
big-calendaror the basic calendar component
Best Practices
- Installation & Updates
- Always use
pnpm dlx shadcn@latest addfor installing components - Check documentation for the latest installation commands
- Keep track of installed components in your project documentation
- Always use
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.
- 6d ago First seen · 116 lines · 738 tokens per session scan A ffec379afc65
402-shadcn is a cursor rule published in the GitHub repository johnpolacek/vibecode.party.starter (27 stars, last pushed 1y ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 738 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 2026-08-30.
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