Auth0 React Integration

Add authentication to React single-page applications using @auth0/auth0-react.

Prerequisites

React 16.11+ application (Vite or Create React App) - supports React 16, 17, 18, and 19
Auth0 account and application configured
If you don't have Auth0 set up yet, use the auth0-quickstart skill first

When NOT to Use

Next.js applications - Use auth0-nextjs skill for both App Router and Pages Router
React Native mobile apps - Use auth0-react-native skill for iOS/Android
Server-side rendered React - Use framework-specific SDK (Next.js, Remix, etc.)
Embedded login - This SDK uses Auth0 Universal Login (redirect-based)
Backend API authentication - Use express-openid-connect or JWT validation instead

Quick Start Workflow

1. Install SDK

npm install @auth0/auth0-react

2. Configure Environment

For automated setup with Auth0 CLI, see Setup Guide for complete scripts.

For manual setup:

Create .env file:

Vite:

VITE_AUTH0_DOMAIN=your-tenant.auth0.com
VITE_AUTH0_CLIENT_ID=your-client-id

Create React App:

REACT_APP_AUTH0_DOMAIN=your-tenant.auth0.com
REACT_APP_AUTH0_CLIENT_ID=your-client-id

3. Wrap App with Auth0Provider

Update src/main.tsx (Vite) or src/index.tsx (CRA):

import React from 'react';
import ReactDOM from 'react-dom/client';
import { Auth0Provider } from '@auth0/auth0-react';
import App from './App';

ReactDOM.createRoot(document.getElementById('root')!).render(
  <React.StrictMode>
    <Auth0Provider
      domain={import.meta.env.VITE_AUTH0_DOMAIN} // or process.env.REACT_APP_AUTH0_DOMAIN
      clientId={import.meta.env.VITE_AUTH0_CLIENT_ID}
      authorizationParams={{
        redirect_uri: window.location.origin
      }}
    >
      <App />
    </Auth0Provider>
  </React.StrictMode>
);

4. Add Authentication UI

import { useAuth0 } from '@auth0/auth0-react';

export function LoginButton() {
  const { loginWithRedirect, logout, isAuthenticated, user, isLoading } = useAuth0();

  if (isLoading) return <div>Loading...</div>;

  if (isAuthenticated) {
    return (
      <div>
        <span>Welcome, {user?.name}</span>
        <button onClick={() => logout({ logoutParams: { returnTo: window.location.origin } })}>
          Logout
        </button>
      </div>
    );
  }

  return <button onClick={() => loginWithRedirect()}>Login</button>;
}

5. Test Authentication

Start your dev server and test the login flow:

npm run dev  # Vite
# or
npm start    # CRA

Detailed Documentation

Setup Guide - Automated setup scripts (Bash/PowerShell), CLI commands, manual configuration
Integration Guide - Protected routes, API calls, error handling, advanced patterns
API Reference - Complete SDK API, configuration options, hooks reference, testing strategies

Common Mistakes

Mistake	Fix
Forgot to add redirect URI in Auth0 Dashboard	Add your application URL (e.g., `http://localhost:3000`, `https://app.example.com`) to Allowed Callback URLs in Auth0 Dashboard
Using wrong env var prefix	Vite uses `VITE_` prefix, Create React App uses `REACT_APP_`
Not handling loading state	Always check `isLoading` before rendering auth-dependent UI
Storing tokens in localStorage	Never manually store tokens - SDK handles secure storage automatically
Missing Auth0Provider wrapper	Entire app must be wrapped in `<Auth0Provider>`
Provider not at root level	Auth0Provider must wrap all components that use auth hooks
Wrong import path for env vars	Vite uses `import.meta.env.VITE_`, CRA uses `process.env.REACT_APP_`

Related Skills

auth0-quickstart - Basic Auth0 setup
auth0-migration - Migrate from another auth provider
auth0-mfa - Add Multi-Factor Authentication

Quick Reference

Core Hooks:

useAuth0() - Main authentication hook
isAuthenticated - Check if user is logged in
user - User profile information
loginWithRedirect() - Initiate login
logout() - Log out user
getAccessTokenSilently() - Get access token for API calls

Common Use Cases:

Login/Logout buttons → See Step 4 above
Protected routes → Integration Guide
API calls with tokens → Integration Guide
Error handling → Integration Guide

auth0-react