01 · 10 min read
Subscription billing architecture for SaaS products on PayOS
Design reliable Customer, Checkout, Payment, Subscription, and entitlement lifecycles on PayOS without treating browser redirects as confirmed proof of payment.
Read guideBuild subscription billing for Vietnamese SaaS from real failure modes.
Technical guides, architectural diagrams, code samples, and production checklists for reliable subscription billing in SaaS.
02 · 11 min read
Safe PayOS webhooks: signatures, idempotency, and reconciliation
Build retry-safe PayOS webhook processing with signature verification and idempotency that never duplicates entitlements and gracefully recovers from dropouts.
Read guide03 · 9 min read
Renewing subscriptions without automatic card debits
Model recurring renewal orders, payment links, grace periods, and customer access when SaaS subscriptions require manual payment confirmation for each period.
Read guide04 · 12 min read
Designing Products, Prices, Subscriptions, and entitlements
A practical VND SaaS billing data model: manage versioned prices, maintain historical audit snapshots, track subscription state, and decouple entitlements.
Read guide05 · 14 min read
Integrating VietBilling with Next.js and NestJS end to end
Integration guide for Next.js and NestJS: configure API keys, manage Customer records, create Checkouts, and verify webhooks to activate user subscriptions.
Read guide06 · 8 min read
Direct PayOS integration or VietBilling for SaaS subscriptions?
Compare building direct PayOS payment links against using VietBilling: code maintenance overhead, edge case handling, renewal flows, and billing reliability.
Read guide07 · 10 min read
Subscription billing architecture for SaaS products on SePay
Design reliable recurring SaaS subscriptions on SePay: one-time renewal checkouts, provider pinning, IPN payment proof, and automated reconciliation.
Read guide08 · 9 min read
Safe SePay IPN webhooks: authentication, idempotency, and void
Authenticate X-Secret-Key, verify ORDER_PAID status, prevent duplicate transactions with idempotent keys, and handle TRANSACTION_VOID edge cases safely.
Read guide