Payment

• CancelTransaction
• ConfirmTransaction
• GetCardToken
• IncrementalAuthorization
• PreAuthorize
• VoidTransaction

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CancelTransaction

• Before Card Presentation: If a card has not been presented yet, the Reader poll sequence stops. The display will show “Cancelling”; the host application must then update the UI using the ShowMessage command.
• During Processing: If the card was already presented but processing is not finished, the system returns CannotCancel. It may take a few seconds to receive the TransactionComplete event while the EMV Core waits for the online result.
• After Completion: If the transaction is already finished, it returns NoTransaction.
• Undoing Success: To undo a completed transaction, use VoidTransaction.
• Declined Transactions: If TransactionComplete returns a Decline status, there is no need to send a VoidTransaction command.
• Events: In all scenarios, EMV Core will eventually send a TransactionComplete event to finalize the state.

 {"jsonrpc": "2.0", "method": "CancelTransaction", "id": 802}

  {"jsonrpc": "2.0", "result": true, "id": 802}

void CancelTransaction();

KIOSK_RET LibOtiKiosk_CancelTransaction(void);

​

ConfirmTransaction

​

API signature

{
  "jsonrpc": "2.0",
  "method": "TransactionComplete",
  "params": {
    "status": "OK",
    "errorCode": 0,
    "errorDescription": "",
    "transactionId": "6103587330",
    "authorizationDetails": {
      "AmountAuthorized": 4.5,
      "AmountRequested": 4.5,
      "AuthorizationCode": "AuthOK",
      "PartialPan": "541333******4111",
      "CardType": "MasterCard",
      "IsTransactionApproved": true,
      "eReceipt": "",
      "Card_ID": "2025-11-25 14:35:39.140|6|3",
      "Card_Balance": 0.0,
      "RRN": "251125123539",
      "TransactionDbID": "6103587330",
      "Transaction_Referance": "6103587330",
      "CardToken": "5VXkNqtUDJBxQj9p/qTGt74jWaPHlRs7xxWa1Yu0gDI=",
      "Additional_Parameters": {
        "SiteId": "6",
        "EntryMode": "4",
        "MachineAuTime": "2025-11-25T14:35:38.885",
        "NayaxTransactionId": "6103587330"
      }
    }
  },
  "id": 701
}

{"jsonrpc":"2.0","method":"ConfirmTransaction", "params": {"amount":450, "fee":0, "productID":42, "transaction_Reference":"6103587330", "AdditionalReceiptData":{"Message": "Purchase confirmed", "VAT_Percentage": 10}}, "id":8}

    {"jsonrpc":"2.0", "result":true, "id":8}

void ConfirmTransaction(String transactionReference, int actualAmountMinorUnits, int productID) throws EmvCoreException;

KIOSK_RET LibOtiKiosk_ConfirmTransaction(uint32_t amount_cents, uint32_t fee_cents, uint32_t product_id, char* transaction_reference, char* additional_receipt_data);

​

GetCardToken

• Payment Cards: Returns a Base64 string containing the card token.
• CLP Cards (for example, Mifare): Returns the card UID.

​

API signature

{
"method": "GetCardToken",
"params": {
"continuous": false,
"timeout": 60
},
"id": 5820
}

   {"jsonrpc": "2.0", "result": true, "id": 5820}

void GetCardToken(int timeoutSeconds, boolean continuous) throws EmvCoreException;

KIOSK_RET LibOtiKiosk_GetCardToken(otiKioskPaymentParameters *params);

​

IncrementalAuthorization

​

Single-step incremental authorization

1. Call PreAuthorize (for example, for $10.00) and read the IncrementalMaxDefaultCredit value from the resulting TransactionComplete event (for example, $50.00).
2. Call ConfirmTransaction, or send an External Settlement request from your server, with an amount up to IncrementalMaxDefaultCredit (for example, $15.03).
3. Nayax Core automatically sends an incremental authorization request to the processor for the difference (in this example, $5.03).
4. If the incremental authorization succeeds, Nayax Core settles the transaction for the final amount ($15.03).
5. If it fails, Nayax Core settles the transaction for the original pre-authorized amount ($10.00).

void IncrementalAuthorization(int amountMinorUnits, int productID, String transactionReference) throws EmvCoreException;

​

PreAuthorize

​

API signature

{"jsonrpc":"2.0","method":"PreAuthorize", "params": {"amount":450, "timeout":10, "productID":0, "continuous":false, "AdditionalReceiptData": {"Message": "Good Morning", "VAT_Percentage": 10}, "isFinalAmount":false, "deferred":false}, "id":801}

   {"jsonrpc": "2.0", "result": true, "id": 801}

void PreAuthorize(int amountMinorUnits, int productID, int timeoutSeconds, boolean continuous, JSONObject additionalReceiptData, boolean isDeferred, boolean isFinalAmount) throws EmvCoreException;

otiKioskPaymentParameters params = {
    .amount_cents = 1500, // $15.00
    .product_id = 12345,
    .timeout_sec = 60,
    .continuous = false,
    .additional_receipt_data = NULL,
    .is_deferred = false,
    .is_final_amount = false
};

KIOSK_RET result = LibOtiKiosk_PreAuthorize(&params);
if (result == KIOSK_RET_OK) {
    printf("Payment initiated successfully\n");
}

​

VoidTransaction

1. Release Funds: The transaction was Pre-Authorized but not Confirmed. Voiding releases the reserved funds when the transaction will no longer occur.
2. Reversal: The transaction was completed using PayTransaction but needs to be canceled.

​

API signature

 {"jsonrpc": "2.0", "method": "VoidTransaction", "params": {"transaction_Reference": "8453F02DFD33413EBA77334B696D5991"}, "id": 803}

 {"jsonrpc": "2.0", "result": true, "id": 803}

void VoidTransaction(String transactionReference) throws EmvCoreException;

KIOSK_RET LibOtiKiosk_VoidTransaction(char* transaction_reference);