Flutterwave v4 Integration with NestJS: Mastering Mobile Money Transfers (Part 1)

Introduction If you’ve spent any time in the African fintech space, you’ve likely used Flutterwave’s v3 API. It was the standard for a while. However, Flutterwave recently launched Version 4 (v4), and it’s not just a minor update—it’s a complete architectural overhaul. V4 moves away from static Public/Secret keys in favor of OAuth 2.0 authentication and introduces the Orchestrator Flow. As a developer, this means better security and more robust transaction handling, but it also means our old integration patterns are officially outdated. In this guide, I’ll show you how to build a production-ready Mobile Money integration using NestJS. Why v4 is a Game Changer The biggest shift in v4 is the OAuth 2.0 lifecycle. Instead of sending your Secret Key with every request, you now exchange your credentials for a Bearer Token that expires. Additionally, the Orchestrator Flow (Direct Transfers) allows you to process a payment by sending all details—Sender, Recipient, and Amount—in one single requ