payments

Payment Processing Best Practices

Payment Security

• Always use HTTPS for all payment-related endpoints
• Implement proper webhook signature verification for all payment providers
• Never store sensitive payment data (use tokens and references)
• Encrypt payment-related data at rest and in transit
• Implement proper access controls for payment endpoints
• Regular security audits for payment processing systems
• Follow PCI DSS compliance requirements

Webhook Implementation

• Verify webhook signatures using timing-safe comparison
• Implement idempotency for all payment webhook events
• Use database transactions for payment state changes
• Handle webhook retries from payment providers gracefully
• Log payment webhook events (excluding sensitive data)
• Monitor webhook success rates and alert on failures
• Test webhook endpoints with payment provider sandbox environments

Payment State Management

• Use database transactions for payment status updates
• Implement proper state machines for payment flows
• Handle edge cases like partial payments and refunds
• Synchronize payment data between local database and payment provider
• Implement proper rollback mechanisms for failed payments
• Track payment history and audit trails
• Handle subscription lifecycle events properly

Error Handling

• Return appropriate HTTP status codes for webhook responses
• Implement proper error logging for payment failures
• Never expose internal payment errors to end users
• Implement graceful degradation for payment system outages
• Handle payment provider API rate limits
• Implement retry logic with exponential backoff
• Monitor payment error rates and patterns

Lemon Squeezy Integration

• Always verify X-Signature header using HMAC-SHA256
• Support critical webhook events: subscription_created, subscription_updated, subscription_cancelled, order_created, order_refunded
• Handle both test and production webhook environments
• Implement proper customer and subscription synchronization
• Use Lemon Squeezy checkout URLs for secure payment processing
• Handle Lemon Squeezy specific payment methods and currencies
• Test integration thoroughly in sandbox environment