cursorrules

A set of coding conventions for React and Next.js, tools for building web interfaces and web applications with JavaScript or TypeScript. It covers code style, types, components, naming, and error handling.

In plain words
What is it for?
Use it when creating or reviewing React and Next.js files, including components, hooks, TypeScript types, exports, and project structure.
Why use it?
It gives the coding agent consistent rules for making new code easier to read, reuse, and maintain.

Cursor rule for Cursor

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/farzannajipour/cursor-react-rules/cursorrules
Clone the repo
git clone --depth 1 https://github.com/Farzannajipour/cursor-react-rules

Made for: Cursor.

Per session 785 This file is loaded in full into every session.
When invoked 785 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 $0.00785 $0.00785
Opus 5 $0.00392 $0.00392
Sonnet 5 $0.00157 $0.00157
Haiku 4.5 $0.00078 $0.00078

Measured yesterday against content hash 56d848095fe2, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

cursorrules 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.

.cursorrules · 108 lines

How it starts

The opening of the file, as written. The whole thing — 108 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Cursor Rules for React + Next.js Development

Core Principles

  • Write clean, maintainable, and performant code
  • Follow React and Next.js best practices
  • Prioritize type safety with TypeScript
  • Focus on component reusability and composition
  • Optimize for both developer experience and user experience

Code Style & Formatting

  • Use functional components with hooks
  • Prefer named exports over default exports
  • Use 2 spaces for indentation
  • Use single quotes for strings
  • Add trailing commas in objects and arrays
  • Use const for variables that don't change
  • Destructure props and state when possible

TypeScript Guidelines

  • Always use TypeScript for new files
  • Define interfaces for all component props
  • Use type inference where obvious
  • Avoid 'any' type - use 'unknown' if type is truly unknown
  • Export types that might be used by other components
  • Use enums for fixed sets of values

Component Structure

  • Order: imports, types, component, exports
  • Keep components small and focused (< 200 lines)
  • Extract complex logic into custom hooks
  • Use composition over prop drilling
  • Implement proper error boundaries

Naming Conventions

  • Components: PascalCase (UserProfile.tsx)
  • Hooks: camelCase with 'use' prefix (useUserData.ts)
  • Utilities: camelCase (formatDate.ts)
  • Constants: UPPER_SNAKE_CASE (API_BASE_URL)
  • Types/Interfaces: PascalCase (UserProfile, ApiResponse)

File Organization

src/
├── app/                 # Next.js app directory
├── components/
│   ├── ui/             # Reusable UI components
│   └── features/       # Feature-specific components
├── hooks/              # Custom React hooks
├── lib/                # Utilities and helpers
├── types/              # Shared TypeScript types
└── styles/             # Global styles

React Best Practices

  • Use React Server Components by default (Next.js 13+)
  • Add 'use client' only when necessary
  • Implement proper loading and error states
  • Use Suspense for async operations
  • Memoize expensive calculations with useMemo
  • Optimize re-renders with useCallback when passing functions as props
  • Use React.lazy for code splitting large components

Read the full file on GitHub · 108 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 · 108 lines · 785 tokens per session scan A 56d848095fe2

Subscribe to this mod's changes

cursorrules is a cursor rule published in the GitHub repository Farzannajipour/cursor-react-rules (2 stars, last pushed 7mo ago), licensed MIT. It adds 785 tokens to every session, about $0.0039 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 2026-08-31.