Simulate payment

API key: Payment · Environment: Sandbox only

Simulates a confirmed payment without moving real funds. The invoice must belong to the authenticated merchant and the sandbox environment. A production key is rejected.

Request body

stage is required and accepts exactly one of:

• paid — pay the remaining amount;
• overpaid — pay the remaining amount plus a random positive excess;
• underpay — pay a random positive part of the remaining amount. If multiple payments are allowed, calls can repeat and payments accumulate; otherwise, the invoice closes as underpaid;
• cancel — cancel an invoice that is still eligible for cancellation.
• paid_late — pay the full expected amount after the deadline. An invoice with no money yet (awaiting_payment) closes as expired, a partly paid one (underpaid_waiting) closes as underpaid, and one already closed as expired or underpaid keeps that status. payment.paid counts only what arrived before the deadline, as in production, where a late payment is credited to your balance separately from the invoice. The invoice gains the late-payment mark, and the only webhook is invoice.paid_late.

For underpay, if token precision or tolerance leaves no positive partial payment below the auto-confirm threshold, the request is rejected without changing the invoice. Status webhooks are sent only when the status changes.

{
  "stage": "paid"
}

The server derives every simulated amount from the invoice. Clients never calculate settlement amounts.

Response (200 OK)

Returns the updated invoice resource and emits the same lifecycle webhook events as the corresponding real outcome. See Get Invoice for the response fields.