Integrate payments with SePay (VietQR), Polar, Stripe, Paddle (MoR subscriptions), Creem.io (licensing). Checkout, webhooks, subscriptions, QR codes, multi-provider orders.

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

payment-integration