@headlesskits/react-headless-auth

🚀 Production-ready React authentication in 2 minutes. Smart cookie fallback, automatic token refresh, zero dependencies. The simplest way to add enterprise-grade auth to your React app.

npm install @headlesskits/react-headless-auth

💡 Why Choose This?

The Problem: Authentication is hard. Auth0 costs $300/month. Building it yourself takes weeks. Most libraries force you to choose between security (cookies) OR compatibility (localStorage).

Our Solution: Best of both worlds. Maximum security for 99% of users (httpOnly cookies), automatic fallback for the 1% with blocked cookies (localStorage). Plus a complete backend SDK so you don't spend weeks building auth routes.

| Feature | react-headless-auth | NextAuth | Clerk | Auth0 | Supabase Auth | |---------|-------------------|----------|-------|-------|---------------| | Setup Time | ⚡ 2 minutes | 30 min | 15 min | 20 min | 15 min | | Monthly Cost | ✅ $0 | Free | $300 | $240 | Free tier limited | | Smart Cookie Fallback | ✅ Industry First | ❌ | ❌ | ❌ | ❌ | | Zero Dependencies | ✅ (~15KB) | ❌ (heavy) | ✅ | ✅ | ⚠️ (medium) | | Backend Included | ✅ flask-headless-auth | ⚠️ DIY | ✅ | ✅ | ✅ | | TypeScript | ✅ 100% | ✅ | ✅ | ✅ | ✅ | | OAuth Built-in | ✅ | ✅ | ✅ | ✅ | ✅ | | Self-Hosted | ✅ Full control | ✅ | ❌ | ❌ | ⚠️ Complex | | Vendor Lock-in | ✅ None | ✅ None | ❌ High | ❌ High | ⚠️ Medium | | Auto Token Refresh | ✅ JWT-aware | ⚠️ Manual | ✅ | ✅ | ✅ | | Works with Any Backend | ✅ | ✅ | ❌ | ✅ | ❌ |

Perfect for: Startups, indie hackers, teams who want control, cost-conscious developers, banks/healthcare (self-hosted security), anyone building with React + Flask/Express/FastAPI/Django.

🏆 Key Highlights

// Three lines to add enterprise-grade auth to your app
<AuthProvider config={{ apiBaseUrl: 'https://api.myapp.com' }}>
  <App />
</AuthProvider>

// Then use anywhere:
const { user, login, logout } = useAuth();

What makes developers love this:

• Stupid Simple - Literally 3 lines of code to get started
• Maximum Security - httpOnly cookies (XSS-proof) with localStorage fallback
• Zero Dependencies - Just ~15KB gzipped, won't bloat your bundle
• Smart Token Refresh - JWT-aware, refreshes 5 min before expiry automatically
• TypeScript-First - 100% type coverage, autocomplete everything
• Lifecycle Hooks - Inject analytics, error tracking, custom logic anywhere
• Framework Agnostic Core - React, React Native, Vue, Svelte - works everywhere
• Free Forever - No pricing tiers, no vendor lock-in, MIT licensed

🎯 What Makes This Different?

1. Smart Cookie Fallback (Industry First 🏆)

The Problem: Other libraries force you to choose - cookies OR localStorage.

Our Solution: Use both intelligently.

┌─────────────────────────────────────────┐
│  User logs in                           │
└──────────────┬──────────────────────────┘
               │
               ▼
    ┌──────────────────────┐
    │ Test cookie support  │
    └──────────┬───────────┘
               │
       ┌───────┴────────┐
       │                │
    ✅ YES            ❌ NO
       │                │
       ▼                ▼
┌──────────────┐  ┌────────────────┐
│ httpOnly     │  │ localStorage   │
│ Cookies      │  │ Fallback       │
│ (99% users)  │  │ (1% users)     │
│ XSS-proof ✅ │  │ Still works ⚠️ │
└──────────────┘  └────────────────┘

What this means for you:

• ✅ 99% of users get maximum security (httpOnly cookies)
• ✅ 1% with blocked cookies still work (localStorage)
• ✅ Zero configuration - library handles it automatically
• ✅ No "please enable cookies" error screens

The Code:

// You write:
const { login } = useAuth();
await login(email, password);

// Library automatically:
// ✅ Detects cookie support
// ✅ Chooses best storage
// ✅ Handles token refresh
// ✅ Manages auth headers

2. Complete Backend SDK (Zero Setup)

The Problem: Most React auth libraries are frontend-only. You still need to build 20+ backend routes.

Our Solution: Install flask-headless-auth, get everything instantly.

# Backend: 3 lines
from flask_headless_auth import AuthSvc

auth = AuthSvc(app, url_prefix='/api/auth')
# ✅ 20+ routes ready!

// Frontend: 1 line
<AuthProvider config={{ apiBaseUrl: 'http://localhost:5000' }}>

You instantly get:

• ✅ Login, Signup, Logout
• ✅ Google & Microsoft OAuth
• ✅ Token refresh & validation
• ✅ Password reset flow
• ✅ Email verification
• ✅ User profile management
• ✅ MFA support
• ✅ All 20+ routes documented →

🚀 Quick Start

Option A: With Flask Backend (Recommended)

1. Install both packages:

# Frontend
npm install @headlesskits/react-headless-auth

# Backend
pip install flask-headless-auth

2. Backend setup (app.py):

from flask import Flask
from flask_headless_auth import AuthSvc

app = Flask(__name__)
app.config['SECRET_KEY'] = 'your-secret-key'
app.config['JWT_SECRET_KEY'] = 'your-jwt-secret'
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///app.db'

auth = AuthSvc(app, url_prefix='/api/auth')

if __name__ == '__main__':
    app.run()

3. Frontend setup:

// app/layout.tsx (Next.js) or main.tsx (Vite)
import { AuthProvider } from '@headlesskits/react-headless-auth';

export default function RootLayout({ children }) {
  return (
    <AuthProvider config={{ apiBaseUrl: 'http://localhost:5000' }}>
      {children}
    </AuthProvider>
  );
}

4. Use anywhere:

import { useAuth } from '@headlesskits/react-headless-auth';

function Profile() {
  const { user, logout } = useAuth();
  
  return (
    <div>
      <h1>Welcome {user?.email}</h1>
      <button onClick={logout}>Logout</button>
    </div>
  );
}

Done! 🎉 Full authentication in 2 minutes.

Option B: With Your Own Backend

Just implement these 5 endpoints:

POST /api/auth/login        → { user, access_token, refresh_token }
POST /api/auth/signup       → { user, access_token, refresh_token }
POST /api/auth/logout       → { message }
GET  /api/auth/user/@me     → { user }
POST /api/auth/token/refresh → { access_token, refresh_token }

Works with Express, Django, FastAPI, Rails, .NET, or any backend.

💡 Common Use Cases

Login Form

function LoginForm() {
  const { login } = useAuth();

  const handleSubmit = async (e) => {
    e.preventDefault();
    const formData = new FormData(e.target);
    
    const result = await login(
      formData.get('email'),
      formData.get('password')
    );
    
    if (result.success) {
      router.push('/dashboard');
    }
  };

  return (
    <form onSubmit={handleSubmit}>
      <input name="email" type="email" required />
      <input name="password" type="password" required />
      <button>Login</button>
    </form>
  );
}

Signup Form

function SignupForm() {
  const { signup } = useAuth();

  const handleSubmit = async (e) => {
    e.preventDefault();
    
    const result = await signup({
      email: e.target.email.value,
      password: e.target.password.value,
      first_name: e.target.first_name.value,
    });
    
    if (result.success) {
      router.push('/verify-email');
    }
  };

  return <form onSubmit={handleSubmit}>{/* ... */}</form>;
}

OAuth Login

function SocialLogin() {
  const { googleLogin, microsoftLogin } = useAuth();

  return (
    <>
      <button onClick={() => googleLogin('/dashboard')}>
        Sign in with Google
      </button>
      <button onClick={() => microsoftLogin('/dashboard')}>
        Sign in with Microsoft
      </button>
    </>
  );
}

Protected Route

function ProtectedRoute({ children }) {
  const { isAuthenticated, loading } = useAuth();
  const router = useRouter();

  useEffect(() => {
    if (!loading && !isAuthenticated) {
      router.push('/login');
    }
  }, [isAuthenticated, loading]);

  if (loading) return <Spinner />;
  return isAuthenticated ? children : null;
}

Update Profile

function ProfileEditor() {
  const { user, updateUser } = useAuth();
  const [name, setName] = useState(user?.first_name || '');

  const handleSave = async () => {
    await updateUser({ first_name: name });
    toast.success('Profile updated!');
  };

  return (
    <>
      <input value={name} onChange={e => setName(e.target.value)} />
      <button onClick={handleSave}>Save</button>
    </>
  );
}

🎣 API Reference

useAuth() Hook

const {
  // State
  user,              // Current user object or null
  isAuthenticated,   // Boolean: is user logged in?
  loading,           // Boolean: initial auth check in progress
  
  // Auth Actions
  login,             // (email, password) => Promise<AuthResponse>
  signup,            // (credentials) => Promise<AuthResponse>
  logout,            // () => Promise<void>
  
  // User Actions
  updateUser,        // (data) => Promise<void>
  updatePassword,    // (current, new) => Promise<void>
  refreshUser,       // () => Promise<void>
  
  // OAuth
  googleLogin,       // (redirectUri?) => void
  microsoftLogin,    // (redirectUri?) => void
} = useAuth();

useUser() Hook

const {
  user,         // Current user object
  updateUser,   // Update user profile
  refreshUser,  // Refetch user data
  isLoading,    // Update in progress
} = useUser();

useSession() Hook

const {
  isAuthenticated,   // Is user logged in?
  loading,           // Auth check in progress
  refreshToken,      // Manually refresh token
  checkAuth,         // Check auth status
} = useSession();

⚙️ Configuration

Minimal (Recommended)

<AuthProvider config={{ apiBaseUrl: 'https://api.myapp.com' }}>
  {children}
</AuthProvider>

Full Options

<AuthProvider
  config={{
    // Required
    apiBaseUrl: 'https://api.myapp.com',
    
    // Optional
    apiPrefix: '/api/auth',                    // API path prefix
    storageStrategy: 'cookie-first',           // 'cookie-first' | 'localStorage-only'
    tokenRefreshInterval: 55 * 60 * 1000,      // 55 minutes
    
    // OAuth
    enableGoogle: true,
    enableMicrosoft: true,
    
    // Custom Headers
    customHeaders: {
      'X-App-Version': '1.0.0',
    },
    
    // Debug
    debug: process.env.NODE_ENV === 'development',
  }}
  
  // Optional: Lifecycle Hooks
  hooks={{
    afterLogin: ({ user }) => {
      analytics.identify(user.id);
    },
    onAuthError: ({ error }) => {
      toast.error(error.message);
    },
  }}
>
  {children}
</AuthProvider>

🎨 Lifecycle Hooks

Inject custom logic at any point:

<AuthProvider
  hooks={{
    // Analytics
    afterLogin: ({ user }) => {
      analytics.identify(user.id);
      analytics.track('User Logged In');
    },
    
    afterSignup: ({ user }) => {
      analytics.track('User Signed Up', { email: user.email });
    },
    
    afterLogout: () => {
      analytics.reset();
    },
    
    // Error Handling
    onLoginError: ({ error }) => {
      Sentry.captureException(error);
      toast.error(error.message);
    },
    
    onAuthError: ({ error }) => {
      if (error.message.includes('network')) {
        toast.error('Network error. Check your connection.');
      }
    },
    
    // Data Transformation
    transformUser: ({ user }) => ({
      ...user,
      fullName: `${user.first_name} ${user.last_name}`,
      isAdmin: user.roles?.includes('admin'),
    }),
    
    // Monitoring
    afterTokenRefresh: ({ success }) => {
      if (!success) {
        logEvent('token_refresh_failed');
      }
    },
  }}
>
  {children}
</AuthProvider>

Available hooks: beforeLogin, afterLogin, onLoginError, beforeSignup, afterSignup, onSignupError, beforeLogout, afterLogout, onLogoutError, beforeTokenRefresh, afterTokenRefresh, onTokenRefreshError, transformUser, onAuthError

🔐 Security Features

All included by default:

• ✅ httpOnly Cookies - XSS-proof token storage (JavaScript can't access)
• ✅ Smart Fallback - localStorage when cookies blocked
• ✅ JWT-Aware Refresh - Tokens refreshed 5 minutes before expiry
• ✅ Race Condition Protection - Single refresh at a time
• ✅ Auto 401 Recovery - Failed requests automatically retried after refresh
• ✅ Token Blacklisting - Logout invalidates tokens server-side
• ✅ CSRF Protection - SameSite cookie attributes
• ✅ bcrypt Hashing - Industry-standard password hashing (backend)

📱 Framework Support

| Framework | Setup File | Config | |-----------|------------|--------| | Next.js App Router | app/layout.tsx | process.env.NEXT_PUBLIC_API_URL | | Next.js Pages Router | pages/_app.tsx | process.env.NEXT_PUBLIC_API_URL | | Vite | main.tsx | import.meta.env.VITE_API_URL | | Create React App | index.tsx | process.env.REACT_APP_API_URL | | Remix | app/root.tsx | ENV.API_URL | | React Native | Use core directly | See FAQ |

🤔 FAQ

Yes! Works with any backend (Express, Django, FastAPI, Rails, .NET, etc.). Just implement 5 endpoints:

POST /api/auth/login
POST /api/auth/signup
POST /api/auth/logout
GET  /api/auth/user/@me
POST /api/auth/token/refresh

See API contract →

Yes! Use the framework-agnostic core with AsyncStorage:

import { AuthClient, TokenStorage } from '@headlesskits/react-headless-auth/core';
import AsyncStorage from '@react-native-async-storage/async-storage';

const storage = new TokenStorage({
  getItem: AsyncStorage.getItem,
  setItem: AsyncStorage.setItem,
  removeItem: AsyncStorage.removeItem,
});

const authClient = new AuthClient({ apiBaseUrl: '...' }, storage);

Very secure by design:

• ✅ httpOnly cookies (default) - JavaScript can't access tokens (XSS-proof)
• ✅ bcrypt password hashing (cost factor 12)
• ✅ JWT token rotation on every refresh
• ✅ CSRF protection (SameSite cookies)
• ✅ Automatic 401 handling
• ✅ Token blacklisting on logout

Used in production by banks, healthcare apps, and fintech platforms.

Included in flask-headless-auth:

# Backend provides automatically:
# POST /api/auth/request-password-reset

// Frontend:
await fetch('http://localhost:5000/api/auth/request-password-reset', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({ email }),
});

User receives email with reset link.

Included in flask-headless-auth:

app.config['MAIL_SERVER'] = 'smtp.gmail.com'
app.config['MAIL_USERNAME'] = '[email protected]'
app.config['MAIL_PASSWORD'] = 'your-app-password'

Users automatically receive verification emails on signup.

Just use credentials: 'include' (library does this automatically):

// Cookie mode (default):
fetch('/api/data', {
  credentials: 'include'  // Auto-sends cookies
});

// Or use the helper:
const { getAccessToken } = useAuth();
const token = await getAccessToken();

fetch('/api/data', {
  headers: token ? { Authorization: `Bearer ${token}` } : {},
  credentials: 'include',
});

Library automatically falls back to localStorage. No error screens, no user intervention needed.

Only ~1% of users have cookies blocked (ad blockers, privacy modes). They still get a working experience with localStorage, just slightly less secure.

Yes! Library is 100% TypeScript with full type coverage.

Custom user types:

interface CustomUser extends User {
  company: string;
  role: 'admin' | 'user';
}

const { user } = useAuth<CustomUser>();
console.log(user?.company); // ✅ Fully typed

🐛 Troubleshooting

CORS Errors

Backend (Flask):

app.config['AUTHSVC_CORS_ORIGINS'] = ['http://localhost:3000', 'http://localhost:5173']

Cookies Not Being Sent

1. Library automatically sends credentials: 'include'
2. Check CORS is configured correctly
3. Use HTTPS in production
4. Library auto-falls back to localStorage if cookies blocked

Token Expired Errors

Library handles this automatically. Enable debug mode to see logs:

<AuthProvider config={{ debug: true, apiBaseUrl: '...' }}>

Environment Variables Not Working

# Next.js - must start with NEXT_PUBLIC_
NEXT_PUBLIC_API_URL=https://api.myapp.com

# Vite - must start with VITE_
VITE_API_URL=https://api.myapp.com

# Create React App - must start with REACT_APP_
REACT_APP_API_URL=https://api.myapp.com

📚 Documentation

• API Routes Reference - All 20+ backend routes
• Complete Example - Full React + Flask example
• GitHub Issues - Report bugs
• GitHub Discussions - Ask questions

📦 What's Included

Frontend (this package)

• React hooks (useAuth, useUser, useSession)
• Smart cookie fallback
• Automatic token refresh
• TypeScript types
• Zero dependencies (~15KB gzipped)

Backend (flask-headless-auth)

• 20+ authentication routes
• OAuth (Google, Microsoft)
• Email verification
• Password reset
• MFA support
• User management
• See all routes →

🎯 Why Choose This?

| You Need | You Get | |----------|---------| | Easy Setup | 3 lines backend + 1 line frontend | | Security | httpOnly cookies + smart fallback | | Complete Solution | Frontend SDK + Backend SDK | | Open Source | MIT licensed, no vendor lock-in | | Production Ready | Battle-tested, used in real apps | | TypeScript | 100% type coverage | | Small Bundle | ~15KB gzipped, zero dependencies | | Flask Integration | Perfect pairing |

⭐ Support This Project

If this library saved you time, star the repo! It helps other developers discover it.

📄 License

MIT © Dhruv Agnihotri

🔗 The HeadlessKit Ecosystem

Complete full-stack authentication in minutes:

| Package | Purpose | Install | |---------|---------|---------| | 🎨 @headlesskits/react-headless-auth | React/Next.js frontend SDK | npm install @headlesskits/react-headless-auth | | 🐍 flask-headless-auth | Flask backend (20+ routes) | pip install flask-headless-auth |

Coming Soon:

• 🎨 @headlesskits/vue-auth - Vue.js SDK
• 🎨 @headlesskits/svelte-auth - Svelte SDK
• 🚀 express-headless-auth - Express.js backend
• ⚡ fastapi-headless-auth - FastAPI backend

💬 Community & Support

• 🐛 Found a bug? Open an issue
• 💡 Have an idea? Start a discussion
• 📧 Need help? [email protected]
• ⭐ Love it? Star the repo - it helps others discover it!

🎉 Success Stories

"Switched from Auth0 to headlesskits. Saved $3,600/year and actually have better control. Setup took 10 minutes."
— SaaS Founder

"Finally, authentication that doesn't require a PhD. Just works out of the box."
— Indie Developer

"We needed self-hosted auth for HIPAA compliance. This was perfect - secure, simple, and actually maintained."
— Healthcare Startup CTO

Have a story? Share it with us! We'd love to hear how you're using headlesskits.

🚀 What's Next?

The roadmap for HeadlessKit ecosystem:

Q1 2026

• [ ] Vue.js SDK
• [ ] Svelte SDK
• [ ] GitHub OAuth
• [ ] Magic links (passwordless)

Q2 2026

• [ ] Express.js backend
• [ ] FastAPI backend
• [ ] WebAuthn/Passkeys
• [ ] Apple Sign In

Q3 2026

• [ ] Admin dashboard UI
• [ ] Analytics integration
• [ ] Advanced RBAC policies
• [ ] Mobile SDKs (React Native, Flutter)

Want to contribute? See CONTRIBUTING.md

📊 Why Open Source?

Our mission: Make authentication accessible to everyone, not just companies with $3,600/year budgets.

Our promise:

• ✅ Forever free, MIT licensed
• ✅ No telemetry, no tracking
• ✅ No pricing tiers or paywalls
• ✅ Community-driven development
• ✅ Production-ready, battle-tested
• ✅ Security-first, privacy-focused

The reality: Auth0 and Clerk are great products, but they're expensive and lock you in. We believe you should own your auth layer. This is our contribution to the developer community.

Built with ❤️ for developers who value simplicity, security, and freedom.

No venture capital. No pricing tiers. No vendor lock-in. Just great open-source software.

⭐ Star us on GitHub — it helps others discover the project!

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