Back to blog
Fintech

Paystack & Flutterwave Integration: A Developer's Guide

Payment gateway integration is more than dropping a checkout button on a page. Here is how we wire Paystack and Flutterwave into fintech and VTU platforms — with webhooks, idempotency, and admin reconciliation.

18 August 20267 min read

Choose the right gateway for your product

Paystack and Flutterwave both serve Nigerian businesses well. Paystack is widely used for card payments and bank transfers. Flutterwave offers broad African coverage and multiple payment methods. Many VTU platforms we build support one or both, depending on client preference and fee structure.

For wallet-based VTU platforms, the gateway handles funding — not individual airtime purchases. VTU provider APIs handle service delivery separately.

Implementation checklist

Every production integration should include:

  • Server-side initialization — never expose secret keys in mobile apps
  • Webhook endpoint with signature verification
  • Idempotent webhook handling (same event processed once)
  • Transaction reference stored before redirecting user to pay
  • Admin view for failed, pending, and successful payments
  • Sandbox testing before going live

Webhook handling done right

When a user funds their wallet, the payment gateway sends a webhook to your server. Your handler must verify the signature, match the reference to a pending transaction, credit the wallet atomically, and return 200 quickly.

If webhook processing fails, users may pay but not receive wallet credit — the most common support issue in new fintech products. Log every webhook payload and build admin tools to manually reconcile edge cases.

Mobile app considerations

Mobile apps should call your backend to initiate payments, not embed secret keys. Use Paystack's mobile SDK or Flutterwave's mobile flow through your API. The app polls or receives push notification when wallet credit completes.

Ready to build your product?

Tell us about your project — we reply on WhatsApp within 24 hours.