Checkout
Checkout shows the customer what they are buying, how they can pay and the amount due before confirmation. It is separate from the merchant workspace.
On this page
Review the order#
Check the store name, purchase, base price and currency. If they differ from your agreement with the seller, ask for a corrected invoice before continuing.
A public invoice only requires its address; access to the seller’s account is not needed. A demo page is clearly marked and does not collect card details for a real charge.
Choose a method#
For a new invoice in the interface, USD offers cards and Alipay; RUB offers SBP; USDT offers crypto. The API can also save USD + crypto for compatibility, but its live crypto payment is blocked with crypto_requires_usdt. USD and USDT are distinct, with no automatic conversion or assumed 1:1 rate. A crypto payment requires a separate USDT invoice.
Card: the browser encrypts payment details with the gateway public key. Kevmi relays the encrypted envelope; its server does not accept or store plaintext card numbers, CVV or one-time bank codes. A requested bank-code form appears only while the gateway’s challenge is valid.
Alipay: the customer supplies a name and receives a QR code. SBP opens the bank payment URL; a gateway-provided QR can also be used. An expiry is shown when the gateway provides one.
Crypto: choose a coin, then an available network from the current catalogue. After creating an operation, checkout displays the exact decimal amount, recipient address and two QR modes: address only, or address and amount. The wallet network must match the chosen network. A USDT invoice price does not lock another coin’s exchange rate: use the amount supplied by the gateway. Expired instructions are hidden while reconciliation continues for the same payment.
For a new live card or Alipay payment, the current gateway supports only feeCustomerPercent=0 and vatCustomerPercent=100: the merchant covers the entire processing fee and VAT is added in full for the customer. Other shares can be saved and calculated on an invoice, but execution is blocked with unsupported_allocation. The server never silently changes saved terms. SBP and USDT crypto payments support every processing-fee share and have no VAT.
Checkout states#
| State | Meaning | Next step |
|---|---|---|
| Active | The invoice is available to view | Check the total and the selected method’s availability |
| Paused / expired / cancelled | No new payment can start through the link | Contact the seller; an original operation is checked separately |
| Not found | The address is invalid or unavailable | Check the complete address |
| Payment unavailable | A new operation is blocked by configuration, method, limit, allocation or merchant review | Follow the displayed message; saved invoice terms do not change |
| Pending / action required | The original operation exists or needs confirmation | Complete the current step or check its status |
| Result being checked | A confirmed result is not yet available | Check the original operation; do not create a second charge |
What confirms payment#
Payment is confirmed by server reconciliation of the exact gateway operation. succeeded requires fulfillment_ready=true, verification=provider_confirmed, no dispute and an exact match between the paid amount and approved total. Crypto additionally requires confirmed settlement evidence.
A redirect, widget message, accepted bank code or browser observation does not confirm money. After a timeout, read the original operation’s status; a replacement attempt is never created automatically.
A new payment and card intent require the merchant’s latest website-review application to be approved. Approval alone does not connect the payment gateway. If the review changes after dispatch, the existing operation remains available for status reads, reconciliation and a requested bank code.
Getting help#
Send the seller the invoice reference or address, the time of the attempt and the error shown. Do not send CVV, a banking password, confirmation code or seed phrase to support. The documentation assistant can explain terms but cannot independently confirm a credit.