🚀 Simple Polar.sh Subscription

A super lightweight Next.js demo showing how to integrate Polar.sh subscriptions with just a few simple functions.

✨ Features

• 5 Simple Functions - All you need to manage subscriptions
• Real-time Data - Always fetches fresh data from Polar.sh
• Automatic Upgrades - Seamlessly switch between plans
• Price Display - Shows formatted pricing with currency
• Success Redirects - Handles payment success gracefully
• Ultra Lightweight - Minimal dependencies and files

📁 Project Structure

├── app/
│   ├── api/polar/route.ts          # Single API endpoint for all Polar operations
│   ├── layout.tsx                   # Basic app layout
│   └── page.tsx                     # Main page
├── components/
│   └── SimplePolar.tsx              # Main subscription dashboard component
├── lib/
│   ├── polar.ts                     # 5 simple functions for everything
│   └── polar-client.ts              # Polar.sh API client (internal)
└── .env.local                       # Configuration

🚀 Quick Start

1. Clone & Install

git clone <your-repo>
cd nextjs
npm install

2. Configure Environment

Create .env.local:

# Your Polar.sh access token (get from dashboard)
POLAR_ACCESS_TOKEN=polar_oat_your_token_here

# Where users return after successful payment
POLAR_SUCCESS_URL=http://localhost:3000?success=true

# Email to test subscriptions with (any email works)
DEMO_USER_EMAIL=your-email@example.com

3. Get Your Polar.sh Token

1. Go to Polar.sh Dashboard
2. Navigate to Settings → API Keys
3. Create a new Personal Access Token
4. Copy it to POLAR_ACCESS_TOKEN in your .env.local

4. Run the Demo

npm run dev

Open http://localhost:3000 in your browser.

📚 How to Use

The demo shows a subscription dashboard that:

1. Shows Current Plan - Displays any active subscription for the configured email
2. Lists Available Plans - Shows all your Polar.sh products with prices
3. Handle Upgrades - Automatically cancels old subscription and creates new one
4. Success Messages - Shows confirmation when payments succeed

Changing the Test Email

Simply update DEMO_USER_EMAIL in .env.local and restart the server. The dashboard will show subscription data for that email address.

🔧 The 5 Simple Functions

All subscription management is handled by these functions in lib/polar.ts:

// Get user's current subscription
const subscription = await getUserSubscription()

// Get all available products/plans
const products = await getProducts()

// Start checkout process for a product
await startCheckout(productId)

// Cancel an active subscription
await cancelSubscription(subscriptionId)

// Check if payment was successful from URL
const success = checkPaymentSuccess()

📝 API Endpoints

The single API endpoint handles everything:

• GET /api/polar?action=products - Get all products
• GET /api/polar?action=subscription - Get user's subscription
• POST /api/polar?action=checkout - Create checkout session
• POST /api/polar?action=cancel - Cancel subscription

💡 Integration Tips

Adding to Your Existing App

1. Copy these files to your project:

   • lib/polar.ts - The 5 simple functions
   • lib/polar-client.ts - Internal API client
   • app/api/polar/route.ts - API endpoint

2. Install dependencies:

   npm install next react

3. Set up environment variables (see above)

4. Use the functions in your components:

   import { getProducts, startCheckout } from './lib/polar'
   
   // In your component
   const products = await getProducts()
   // Show products, then on click:
   await startCheckout(productId)

Customizing the UI

The SimplePolar.tsx component is just an example. You can:

• Replace it with your own design
• Use the 5 functions in lib/polar.ts anywhere in your app
• Style it to match your brand
• Add additional features like trial periods, etc.

Production Deployment

1. Update POLAR_SUCCESS_URL to your production domain
2. Make sure your Polar.sh products are published
3. Test with real email addresses
4. Deploy normally (Vercel, Netlify, etc.)

💾 Database Integration Examples

The code includes helpful comments showing where to add database logic. Here are complete examples:

🐛 Troubleshooting

"Checkout failed"

• Check your POLAR_ACCESS_TOKEN is correct
• Verify the product exists and is published in Polar.sh

"No subscription found"

• The email in DEMO_USER_EMAIL doesn't have an active subscription
• Try subscribing to a plan first

Redirect not working

• Check POLAR_SUCCESS_URL matches your domain
• Make sure the URL includes ?success=true

🤝 Support

• Polar.sh Documentation
• Polar.sh Discord
• Check the browser console for detailed error messages

📄 License

MIT - Use this however you want!

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Built with ❤️ for the Polar.sh community