Accepting Crypto Payments: The Merchant Gateway

Invoices, hosted checkout, API keys, and webhooks — the merchant side of OpenPay Pro in one guide.

OpenPay Pro Team · Jul 5, 2026 · 8 min read

AdvancedMerchants

If the deposit gateway is how you fund yourself, the payment gateway is how you get paid by other people. It turns an amount into a hosted checkout page a customer can pay from any supported chain.

Invoices and hosted checkout

Create an invoice with an amount, a currency, and an optional reference. The gateway returns a public checkout URL with a payment token. The customer picks an asset, sends the payment, and the page tracks confirmation in real time.

Settlement rules

  • Underpayments are recorded and never silently marked as paid
  • Overpayments credit the full received amount
  • Late payments after expiry are flagged for review rather than dropped

API keys and webhooks

Merchants generate scoped API keys from the merchant dashboard and register a webhook URL. Every status change posts a signed payload; verify the signature before acting on it, and treat delivery as at-least-once.

  1. 1Create an API key in the merchant dashboard
  2. 2Register your webhook endpoint
  3. 3Verify the signature on every request
  4. 4Mark the order paid only after a confirmed status

Try it in the wallet

Open OpenPay Pro and follow along with this guide.

Open OpenPay Pro