Technical Summary
To implement the iPay payment gateway, create a REST API URL and link it to a payment button or link on your website or backoffice. When a user initiates a payment (e.g., via a “Buy” or “Deposit” button), they are directed to the on-ramp provider to complete the transaction. After completing it, the user is sent back to the redirect URL you registered with iPay (e.g., your deposit-success page).
Once funds are deposited into your crypto wallet, iPay sends a server-to-server HTTP POST request to your specified callback URL (Instant Payment Notification URL). This POST contains a JSON payload with transaction details, enabling real-time updates to your system. Optionally, verify callbacks using a secret token sent in the authorization header for added security.
The redirect only closes the user journey. Credit deposits from the callback, never from the redirect page load.
For the bigger-picture rationale behind this architecture, see how crypto on-ramps solve high-risk payment processing.