react

react is a cursor rule for Cursor from PatrickJS/awesome-cursorrules. It costs 460 tokens per session, scanned A, original, CC0-1.0.

A set of general rules for building modern React web applications with small functional components, hooks, shared state, forms, and performance practices.

In plain words
What is it for?
Use it when creating or reviewing React components, custom hooks, forms, shared state, loading behavior, and rendering performance.
Why use it?
It encourages consistent component structure and state handling, making large interfaces easier to read, reuse, and maintain.

Cursor rule for Cursor

Written for Cursor: a Cursor rule (.mdc).

Good fit Use it when creating or reviewing React components, custom hooks, forms, shared state, loading behavior, and rendering performance.

Compare 6 cursor rules from other repositories ↓
Install with agentmods
npx agentmods add rules/patrickjs/awesome-cursorrules/react
About the project

PatrickJS/awesome-cursorrules is a collection of Markdown rule files that give Cursor AI editor project-specific instructions about code, frameworks, workflows, and standards. Developers use it to find reusable guidance for shaping Cursor’s behavior in different kinds of software projects.

PatrickJS/awesome-cursorrules · 40,734 stars · on GitHub

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.

Clone the repo
git clone --depth 1 https://github.com/PatrickJS/awesome-cursorrules

Made for: Cursor.

Wrote 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.

agentmods badge for react

README.md
[![agentmods](https://agentmods.dev/badge/rules/patrickjs/awesome-cursorrules/react.svg)](https://agentmods.dev/rules/patrickjs/awesome-cursorrules/react)
Your own site
<a href="https://agentmods.dev/rules/patrickjs/awesome-cursorrules/react"><img src="https://agentmods.dev/badge/rules/patrickjs/awesome-cursorrules/react.svg" alt="Measured on agentmods" height="20"></a>
Per session 460 This file is loaded in full into every session.
When invoked 460 The same file — it is already loaded in full.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00460 $0.00460
Opus 5 $0.00230 $0.00230
Sonnet 5 $0.00092 $0.00092
Haiku 4.5 $0.00046 $0.00046

Measured 4d ago against content hash e4e0ddf0ae8e, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

react 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 4d 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.

Origin

Copies of this mod

6 near-identical copies found in the catalogue:

  • react — 97% identical, 7 lines differ
  • react — 97% identical, 7 lines differ
  • react — 97% identical, 7 lines differ
  • react — 97% identical, 7 lines differ
  • react — 97% identical, 7 lines differ
  • react — 91% identical, 1 lines differ
rules/react.mdc · 79 lines

How it starts

The opening of the file, as written. The whole thing — 79 lines — stays where its author put it; the contents beside it link to each section on GitHub.

React Best Practices

Component Structure

  • Use functional components over class components
  • Keep components small and focused
  • Extract reusable logic into custom hooks
  • Use composition over inheritance
  • Implement proper prop types with TypeScript
  • Split large components into smaller, focused ones

Hooks

  • Follow the Rules of Hooks
  • Use custom hooks for reusable logic
  • Keep hooks focused and simple
  • Use appropriate dependency arrays in useEffect
  • Implement cleanup in useEffect when needed
  • Avoid nested hooks

State Management

  • Use useState for local component state
  • Implement useReducer for complex state logic
  • Use Context API for shared state
  • Keep state as close to where it's used as possible
  • Avoid prop drilling through proper state management
  • Use state management libraries only when necessary

Performance

  • Implement proper memoization (useMemo, useCallback)
  • Use React.memo for expensive components
  • Avoid unnecessary re-renders
  • Implement proper lazy loading
  • Use proper key props in lists
  • Profile and optimize render performance

Forms

  • Use controlled components for form inputs
  • Implement proper form validation
  • Handle form submission states properly
  • Show appropriate loading and error states
  • Use form libraries for complex forms
  • Implement proper accessibility for forms

Error Handling

  • Implement Error Boundaries
  • Handle async errors properly
  • Show user-friendly error messages
  • Implement proper fallback UI
  • Log errors appropriately
  • Handle edge cases gracefully

Testing

  • Write unit tests for components
  • Implement integration tests for complex flows
  • Use React Testing Library
  • Test user interactions
  • Test error scenarios
  • Implement proper mock data

Accessibility

  • Use semantic HTML elements
  • Implement proper ARIA attributes
  • Ensure keyboard navigation
  • Test with screen readers
  • Handle focus management
  • Provide proper alt text for images

Code Organization

  • Group related components together
  • Use proper file naming conventions
  • Implement proper directory structure
  • Keep styles close to components
  • Use proper imports/exports
  • Document complex component logic

Read the full file on GitHub · 79 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. 4d ago First seen · 79 lines · 460 tokens per session scan A e4e0ddf0ae8e

Subscribe to this mod's changes

react is a cursor rule published in the GitHub repository PatrickJS/awesome-cursorrules (40,734 stars, last pushed 3mo ago), licensed CC0-1.0. It adds 460 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 2026-09-03.