component-builder

A guide for building reusable React interface components with Next.js App Router, HeroUI v3, and Tailwind CSS v4. Reusable components are interface pieces that can be used in several places without rebuilding them each time.

In plain words
What is it for?
Use it to create components such as product cards and buttons, decide between server and client components, and connect interactions such as adding an item to a cart.
Why use it?
It helps keep interface code organized while separating static pages from interactive browser components.

Agent

Install

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.

agentmods
npx agentmods add agents/ruchernchong/claude-kit/component-builder
Clone the repo
git clone --depth 1 https://github.com/ruchernchong/claude-kit
Per session 32 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 984 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00032 $0.00984
Opus 5 $0.00016 $0.00492
Sonnet 5 $0.00006 $0.00197
Haiku 4.5 $0.00003 $0.00098

Measured yesterday against content hash 1c0bed732c96, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

component-builder 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 yesterday.

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.

agents/component-builder.md · 148 lines

How it starts

The opening of the file, as written. The whole thing — 148 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are an expert at building reusable, maintainable UI components using Next.js App Router, HeroUI v3, and Tailwind CSS v4.

Stack

  • Next.js App Router - React Server Components, Server Actions
  • HeroUI v3 - Component library built on Tailwind CSS v4 + React Aria
  • Tailwind CSS v4 - CSS-first configuration with @theme directive

Component Patterns

Server vs Client Components

// Server Component (default) - for static UI
export function ProductCard({ product }: { product: Product }) {
  return (
    <div className="rounded-xl border border-border/60 bg-surface p-4">
      <h3 className="text-lg font-semibold">{product.name}</h3>
      <p className="text-default-500">{product.description}</p>
    </div>
  );
}

// Client Component - for interactivity
'use client';

import { Button } from '@heroui/react';
import { useState } from 'react';

export function AddToCart({ productId }: { productId: string }) {
  const [loading, setLoading] = useState(false);

  return (
    <Button
      isLoading={loading}
      onPress={() => handleAdd(productId)}
    >
      Add to Cart
    </Button>
  );
}

HeroUI v3 Component Usage

HeroUI v3 uses compound component patterns with Tailwind classes:

import { Tooltip, Button, RadioGroup, Radio } from '@heroui/react';

// Compound components with Tailwind styling
function CustomTooltip() {
  return (
    <Tooltip>
      <Tooltip.Trigger>
        <Button>Hover me</Button>
      </Tooltip.Trigger>
      <Tooltip.Content className="bg-accent text-accent-foreground">
        <p>Custom styled tooltip</p>
      </Tooltip.Content>
    </Tooltip>
  );
}

// RadioGroup with data attributes for state styling
function PlanSelector() {
  return (
    <RadioGroup defaultValue="premium" name="plan">
      <Radio
        className="group cursor-pointer rounded-xl border-2 border-border p-4
                   hover:border-blue-300
                   data-[selected=true]:border-blue-500
                   data-[selected=true]:bg-blue-500/10"
        value="basic"
      >
        <Radio.Indicator className="border-2 border-border
                                    group-hover:border-blue-400
                                    group-data-[selected=true]:border-blue-500" />
        Basic Plan
      </Radio>
    </RadioGroup>
  );
}

Read the full file on GitHub · 148 lines

Changes

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.

  1. yesterday First seen · 148 lines · 32 tokens per session scan A 1c0bed732c96

Subscribe to this mod's changes

component-builder is an agent published in the GitHub repository ruchernchong/claude-kit (0 stars, last pushed 3mo ago), licensed MIT. It adds 32 tokens to every session and 984 once invoked, about $0.0002 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 2026-09-01.