Skip to main content

​
Unreal Engine Integration

Gx402 provides Blueprint-first and C++-first patterns for calling x402 via your Express middleware. Unreal packaging, platform constraints, and input methods differ from Unity — this guide focuses on practical handoff patterns (deep links, companion apps, WalletConnect).

​
Prerequisites

  • Unreal Engine 4.27+ or Unreal Engine 5
  • A way to open external browser or webview from a packaged game (for WalletConnect)
  • Companion app / deep-link support for consoles or tight packaging scenarios
  • A Gx402 Express middleware running the /create-payment and /confirm-payment endpoints

​
Typical flow (packaged & Blueprint-friendly)

  1. Player triggers purchase in UI (Blueprint event).
  2. CreatePaymentNode calls your backend /create-payment.
  3. Backend returns payload + paymentId.
  4. Game opens WalletConnect session (external browser or system webview).
  5. Wallet signs payload; companion app or deep-link returns signature.
  6. Game calls /confirm-payment with signature to finalize.

​
Blueprint concept

  • OnBuy -> CreatePaymentNode -> OnSuccess -> OpenWalletConnect -> Wait -> ConfirmPaymentNode -> OnFinal grant item.

​
C++ (pseudo)

// C++ concept using FHttpModule
void UMyStore::CreatePayment(FString ItemId) {
  // POST /create-payment -> parse payload, paymentId
  // Launch external WalletConnect URL
  // Wait for a REST callback or deep link to deliver signature
  // POST /confirm-payment with signature
}