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Billions provides a hosted payment flow for accepting payments without building your own checkout or payment-status infrastructure. Your backend creates an invoice, redirects the customer to the hosted payment page, and confirms the result by retrieving the invoice from the authenticated Billions API.

Integrate the payment flow

Follow the complete path from API credentials to production launch.

Start from an example

Create an invoice, handle a callback, and retrieve invoices from the API.

Choose an SDK

Use the TypeScript or PHP SDK to integrate the Billions API.

Connect a store

Add Billions to WooCommerce with the official plugin.

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How the integration works

1

Create an invoice

Your backend sends the amount, currency, order reference, callback URL, and an idempotency key to Billions.
2

Redirect the customer

Open the returned invoice_url. The customer completes payment on the Billions-hosted page.
3

Receive a callback

Billions notifies your callback endpoint that the invoice may have changed.
4

Verify with the API

Retrieve the invoice from the authenticated API and update the order only from that response.
Never mark an order as paid from callback fields alone. Treat the callback as a signal to retrieve the current invoice from the Billions API.

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Choose a path