payment-integration

Integrate Polar or Sepay by connecting their APIs and SDKs to your Node.js backend, configuring authentication credentials, and implementing checkout session creation. Both gateways provide language-specific SDKs and webhook support for handling payment events and subscription lifecycles.

Webhook verification ensures incoming events from payment providers are authentic by validating cryptographic signatures. Implement signature validation before processing subscription updates, payment confirmations, or refund notifications from Polar or Sepay webhooks.

Both Polar and Sepay support subscription management with recurring billing. Polar includes usage-based billing and automated benefit delivery, while Sepay handles VietQR/NAPAS QR generation and bank transfers across 44+ Vietnamese banks and virtual accounts.

Sepay supports VietQR, NAPAS QR, bank transfers, and virtual accounts across 44+ partner banks in Vietnam. Polar provides subscription-based billing with merchant-of-record tax compliance and multilingual SDK support across Node.js, PHP, Python, Go, Laravel, and Next.js.

Polar includes built-in merchant-of-record tax compliance for subscription billing, reducing manual tax handling. Sepay focuses on payment processing and QR generation; tax compliance depends on your jurisdiction and sales context.

Create a checkout session by specifying product ID, price, and subscription frequency through the payment gateway's API. Both Polar and Sepay return secure session URLs for customers to complete payment while maintaining PCI compliance through tokenized transactions.