# React Guidelines

> React coding guidelines and best practices. MUST follow these rules. Use when reviewing or writing React code or tasks.

- Skill: `diegosouzapw/react-guidelines` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add diegosouzapw/react-guidelines`
- Raw SKILL.md: https://api.skillmd.com/api/skills/diegosouzapw/react-guidelines/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Web & Frontend
- Author: diegosouzapw (https://skillmd.com/u/diegosouzapw)
- Updated: 2026-09-08
- Page: https://skillmd.com/skills/diegosouzapw/react-guidelines

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# IMPORTANT Frontend Guidelines

- NEVER use `useState` or `useEffect` directly in React Components. ALWAYS use custom hook in separated for that (e.g., `useBot`, `useBacktesting`).
- NEVER combine multiple hooks or components in a single file, even if they are small. EVERY hook, component or Modal should have its OWN file, e.g., `useBot.ts`, `BotComponent.tsx`.
- React components should ALWAYS be functions with default export (`export default function ComponentName() {}`), not class-based or arrow functions.
- NEVER use `any` type OR anonymous types in TypeScript, ALWAYS use explicit types, if not existing - create them.
- If any frontend changes are made, run `cd <path-to-project> && npx tsc --noEmit --skipLibCheck --project tsconfig.app.json && npx eslint .` and ensure no errors. DON'T run build for production to make sure the code is not broken.
- If any frontend changes are made for `*.{js,ts,jsx,tsx,css,json,scss}` files, run `cd <path-to-project> && npx prettier <path/to/file> --write` and ensure no errors.
- When creating a new React page, follow the provided instructions in [`references/instructions.md`](./references/instructions.md).