Payment System

Overview

The NextAI starter kit includes a complete payment system powered by Stripe, allowing you to monetize your AI application through subscriptions or a credit-based system. The implementation is beginner-friendly and requires minimal configuration.

Features

• Stripe integration for secure payment processing
• Credit-based system for pay-as-you-go usage
• Customizable subscription plans
• Automatic webhook handling
• User-friendly checkout process

Setup

Environment Variables

Configure your Stripe credentials in the .env file:

# Stripe Configuration
STRIPE_PUBLISHABLE_KEY=your_publishable_key
STRIPE_SECRET_KEY=your_secret_key
STRIPE_WEBHOOK_SECRET=your_webhook_secret
NEXT_PUBLIC_STRIPE_CUSTOMER_PORTAL_LINK=your_customer_portal_link
 
# Credit System Configuration (Optional)
CREDIT_PRICE_USD=0.10

You can obtain these keys from your Stripe Dashboard (opens in a new tab).

Testing

Test Cards

Use these test card numbers during development:

• Success: 4242 4242 4242 4242
• Decline: 4000 0000 0000 0002

Local Testing

1. Install the Stripe CLI (opens in a new tab)
2. Forward webhooks to your local environment:

stripe listen --forward-to localhost:3000/api/stripe/webhook

Troubleshooting

Common Issues

1. Webhook Errors

   • Verify webhook secret is correct
   • Check webhook endpoint is accessible
   • Ensure proper event handling

2. Payment Failures

   • Validate payment amount
   • Check customer information
   • Review Stripe logs

3. Credit System Issues

   • Verify credit price configuration
   • Check database connections
   • Review transaction logs

For more detailed information about Stripe integration, visit the Stripe Documentation (opens in a new tab).