react-nextjs-app

A Next.js App Router convention based on the app folder and file-system routing. It explains server and client components, layouts, loading and error files, route groups, parallel routes, and API route handlers.

In plain words
What is it for?
Use it when building Next.js applications with the App Router, including nested layouts, loading and error screens, client-side interactions, and API endpoints.
Why use it?
It clarifies which files control each part of a route and when code should run on the server or in the browser.

Skill for Claude CodeCodex

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 skills/ggombee/code-forge/react-nextjs-app
Any agent
npx skills add ggombee/code-forge --skill react-nextjs-app
Clone the repo
git clone --depth 1 https://github.com/ggombee/code-forge

Made for: Claude Code, Codex.

Per session 31 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,663 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 $0.00031 $0.01663
Opus 5 $0.00015 $0.00831
Sonnet 5 $0.00006 $0.00333
Haiku 4.5 $0.00003 $0.00166

Measured yesterday against content hash c08acfdc791a, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

react-nextjs-app 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.

modules/frameworks/react-nextjs-app/SKILL.md · 297 lines

How it starts

The opening of the file, as written. The whole thing — 297 lines — stays where its author put it; the contents beside it link to each section on GitHub.

React & Next.js App Router 컨벤션

이 프로젝트는 Next.js App Router를 사용한다. app/ 디렉토리 기반의 파일 시스템 라우팅을 따른다.


디렉토리 구조

app/
├── layout.tsx          # 루트 레이아웃 (필수)
├── page.tsx            # 루트 페이지
├── loading.tsx         # 로딩 UI
├── error.tsx           # 에러 UI
├── not-found.tsx       # 404 UI
├── (auth)/             # Route Group (URL에 포함되지 않음)
│   ├── login/
│   │   └── page.tsx
│   └── register/
│       └── page.tsx
├── dashboard/
│   ├── layout.tsx      # 중첩 레이아웃
│   ├── page.tsx
│   └── @analytics/     # Parallel Route
│       └── page.tsx
└── api/                # Route Handlers
    └── users/
        └── route.ts

Server vs Client Components

Server Component (기본값)

// app/orders/page.tsx - 서버 컴포넌트 (기본값)
import { db } from '@/lib/db';

// async 함수 사용 가능
export default async function OrdersPage() {
  const orders = await db.orders.findMany();

  return (
    <ul>
      {orders.map((order) => (
        <li key={order.id}>{order.name}</li>
      ))}
    </ul>
  );
}

Client Component

// app/orders/OrderFilters.tsx
'use client'; // 반드시 파일 최상단에 선언

import { useState } from 'react';

export function OrderFilters() {
  const [filter, setFilter] = useState('all');

  return (
    <select value={filter} onChange={(e) => setFilter(e.target.value)}>
      <option value="all">전체</option>
      <option value="pending">대기중</option>
    </select>
  );
}
// ✅ 좋은 예: Server Component가 Client Component를 children으로 받음
// app/orders/layout.tsx (Server Component)
import { OrderFilters } from './OrderFilters'; // Client Component

export default function OrdersLayout({ children }: { children: React.ReactNode }) {
  return (
    <div>
      <OrderFilters />
      {children}
    </div>
  );
}

// ❌ 나쁜 예: 불필요하게 'use client' 추가
'use client';
// useState, useEffect 없이 'use client' 선언
export default function StaticCard({ title }: { title: string }) {
  return <div>{title}</div>;
}

metadata API

// app/orders/page.tsx - 정적 메타데이터
import type { Metadata } from 'next';

export const metadata: Metadata = {
  title: '주문 목록',
  description: '전체 주문 내역을 확인합니다.',
};

export default function OrdersPage() { ... }

Read the full file on GitHub · 297 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 · 297 lines · 31 tokens per session scan A c08acfdc791a

Subscribe to this mod's changes

react-nextjs-app is a skill published in the GitHub repository ggombee/code-forge (13 stars, last pushed 2mo ago), licensed MIT. It adds 31 tokens to every session and 1,663 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 2026-08-30.

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