nextjs-patterns

A set of patterns for building Next.js pages and components, including when to use server or client components, how to fetch data, and how to handle errors.

In plain words
What is it for?
Use it when creating Next.js pages, interactive components, server-side data fetching, or error screens.
Why use it?
It gives developers consistent ways to structure Next.js code and avoids unnecessary client-side code or missing error handling.

Cursor rule

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 rules/kabi10/cursor-rules/nextjs-patterns
Clone the repo
git clone --depth 1 https://github.com/Kabi10/cursor-rules
Per session 456 This file is loaded in full into every session.
When invoked 456 The same file — it is already loaded in full.
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 $0.00456 $0.00456
Opus 5 $0.00228 $0.00228
Sonnet 5 $0.00091 $0.00091
Haiku 4.5 $0.00046 $0.00046

Measured yesterday against content hash 81db16eda369, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

nextjs-patterns 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/patterns/nextjs-patterns.mdc · 87 lines

What it actually says

Next.js Patterns

🔄 Component Patterns

  1. Server Components (Default)

    // ✅ Correct: Default to Server Components
    export default async function Page({ params }) {
      const data = await getData();
      return <Component data={data} />;
    }
    
  2. Client Components (When Needed)

    // ✅ Correct: Mark as client when needed
    'use client';
    
    export function InteractiveComponent() {
      const [state, setState] = useState();
      return <div onClick={() => setState(!state)}>{state}</div>;
    }
    

📡 Data Fetching

  1. Server-Side Data Fetching

    // ✅ Correct: Fetch in Server Components
    async function getData() {
      const res = await fetch('https://api.example.com/data', {
        next: { revalidate: 3600 }
      });
      return res.json();
    }
    
  2. Error Handling

    // ✅ Correct: Use error.tsx
    export default function Error({
      error,
      reset,
    }: {
      error: Error;
      reset: () => void;
    }) {
      return (
        <div>
          <h2>Something went wrong!</h2>
          <button onClick={() => reset()}>Try again</button>
        </div>
      );
    }
    

Examples

Critical Rules

  • Default to Server Components
  • Use 'use client' only when necessary
  • Implement proper error boundaries
  • Include loading states
  • Follow Next.js file conventions
  • Use metadata API for SEO description: globs: alwaysApply: false

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 · 87 lines · 456 tokens per session scan A 81db16eda369

Subscribe to this mod's changes

nextjs-patterns is a cursor rule published in the GitHub repository Kabi10/cursor-rules (21 stars, last pushed 2mo ago), licensed MIT. It adds 456 tokens to every session, about $0.0023 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.