Payment Integration
Production-proven payment processing with SePay (Vietnamese banks), Polar (global SaaS), Stripe (global infrastructure), Paddle (MoR subscriptions), and Creem.io (MoR + licensing).
When to Use
- •Payment gateway integration (checkout, processing)
- •Subscription management (trials, upgrades, billing)
- •Webhook handling (notifications, idempotency)
- •QR code payments (VietQR, NAPAS)
- •Software licensing (device activation)
- •Multi-provider order management
- •Revenue splits and commissions
Platform Selection
| Platform | Best For |
|---|---|
| SePay | Vietnamese market, VND, bank transfers, VietQR |
| Polar | Global SaaS, subscriptions, automated benefits (GitHub/Discord) |
| Stripe | Enterprise payments, Connect platforms, custom checkout |
| Paddle | MoR subscriptions, global tax compliance, churn prevention |
| Creem.io | MoR + licensing, revenue splits, no-code checkout |
Quick Reference
SePay
- •
references/sepay/overview.md- Auth, supported banks - •
references/sepay/api.md- Endpoints, transactions - •
references/sepay/webhooks.md- Setup, verification - •
references/sepay/sdk.md- Node.js, PHP, Laravel - •
references/sepay/qr-codes.md- VietQR generation - •
references/sepay/best-practices.md- Production patterns
Polar
- •
references/polar/overview.md- Auth, MoR concept - •
references/polar/products.md- Pricing models - •
references/polar/checkouts.md- Checkout flows - •
references/polar/subscriptions.md- Lifecycle management - •
references/polar/webhooks.md- Event handling - •
references/polar/benefits.md- Automated delivery - •
references/polar/sdk.md- Multi-language SDKs - •
references/polar/best-practices.md- Production patterns
Stripe
- •
references/stripe/stripe-best-practices.md- Integration design - •
references/stripe/stripe-sdks.md- Server SDKs - •
references/stripe/stripe-js.md- Payment Element - •
references/stripe/stripe-cli.md- Local testing - •
references/stripe/stripe-upgrade.md- Version upgrades - •External: https://docs.stripe.com/llms.txt
Paddle
- •
references/paddle/overview.md- MoR, auth, entity IDs - •
references/paddle/api.md- Products, prices, transactions - •
references/paddle/paddle-js.md- Checkout overlay/inline - •
references/paddle/subscriptions.md- Trials, upgrades, pause - •
references/paddle/webhooks.md- SHA256 verification - •
references/paddle/sdk.md- Node, Python, PHP, Go - •
references/paddle/best-practices.md- Production patterns - •External: https://developer.paddle.com/llms.txt
Creem.io
- •
references/creem/overview.md- MoR, auth, global support - •
references/creem/api.md- Products, checkout sessions - •
references/creem/checkouts.md- No-code links, storefronts - •
references/creem/subscriptions.md- Trials, seat-based - •
references/creem/licensing.md- Device activation - •
references/creem/webhooks.md- Signature verification - •
references/creem/sdk.md- Next.js, Better Auth - •External: https://docs.creem.io/llms.txt
Multi-Provider
- •
references/multi-provider-order-management-patterns.md- Unified orders, currency conversion
Scripts
- •
scripts/sepay-webhook-verify.js- SePay webhook verification - •
scripts/polar-webhook-verify.js- Polar webhook verification - •
scripts/checkout-helper.js- Checkout session generator
Key Capabilities
| Platform | Highlights |
|---|---|
| SePay | QR/bank/cards, 44+ VN banks, webhooks, 2 req/s |
| Polar | MoR, subscriptions, usage billing, benefits, 300 req/min |
| Stripe | CheckoutSessions, Billing, Connect, Payment Element |
| Paddle | MoR, overlay/inline checkout, Retain (churn prevention), tax |
| Creem.io | MoR, licensing, revenue splits, no-code checkout |
Implementation
See references/implementation-workflows.md for step-by-step guides per platform.
General flow: auth → products → checkout → webhooks → events