The purpose of the Payment Engine SDK is to allow the developer to easily implement payments into their system.

Initate Transaction

This is called after all other required and optional transaction-relevant parameters have been set.

There are two types of main transactions that can be initiated: in-scope and out-of-scope. Only one can be called per transaction.

---

Out-of-scope

Use the out-of-scope function when the user needs to provide their credit card information.

This type of transaction gives over control to the SDK to acquire the sensitive credit card data from the user via a pop-up message on the screen or on a credit card device, and then processes the transaction with the gateway.

In-scope

Use the in-scope function when there is no need for the SDK to interact with the user (for example, when you pass through the card number to the SDK or when running a void, etc.). When using this function, you cannot set any device-specific parameters.

Variable	Required	Description	Sample Data
xApproved	No	Indicates whether to return approved transactions True/False value * If left blank, returns all transactions (approved and not approved).	TRUE
xBeginDate	No	Transaction begin date	2019-01-15
xEndDate	No	Transaction end date This field can only be changed before the schedule is completed.	2019-01-31

---

Basic Parameters

Name	Required	Description	Sample Data
xKey	Yes	Cardknox account key	CardknoxSupport_Test
xVersion	Yes	Gateway version	4.5.8
xSoftwareName	Yes	Name of your software	My app
xSoftwareVersion	Yes	Version number of your software	1.0.0

---

Transaction Specific

Name	Required	Description	Sample Data
xCommand	Yes* Use this to submit any CC or ACH command. See Transaction Types.	Cardknox transaction type	cc:Sale
xAmount	Yes	Total amount of the transaction, including tax and tip, if applicable.	3.0
xAllowDuplicate	No	By default, Cardknox rejects duplicate transactions within 10 minutes of the original transaction. This command overrides that safeguard. True/False allowed.	True
RequireAVS	No	Requires the user to enter their street address and ZIP Code (only affects keyed transactions). True/False allowed.	True
RequireCVV	No	Requires the user to enter CVV (only affects keyed transactions). True/False allowed.	True

---

Form Settings

Name	Required	Description	Sample Data
ExitFormIfApproved	No	Returns control to the calling application if the transaction is approved. True/False allowed.	True
ExitFormIfNotApproved	No	Returns control to the calling application if the transaction is not approved. True/False allowed.	True
ExitFormOnDeviceError	No	Returns control to the calling application after any device error. True/False allowed.	True

---

Device Settings

Name	Required	Description	Sample Data
EnableDeviceInsertSwipeTap	No	Enables the use of a credit card device for card-present transactions. True/False allowed.	True
Device_Set	No* Required if EnableDeviceInsertSwipeTap is set to True	Sets specific device parameters.	Device_Set(“Verifone_Mx915.4”, “COM11”, “115200”, “N”, “8”); IP: “Verifone_Mx915.4”, “10.166.110.101”, “9001”

---

PIN Signature

Name	Required	Description	Sample Data
EnableDeviceSignature	No	Prompt for signature after the transaction is approved. True/False allowed.	True
EnableDeviceSignature_MinAmount	No	Prompt for signature only if xAmount is greater than the amount set here. EnableDeviceSignature must be set.	5
EnableDevicePin	No	Set the device to prompt for a PIN on swiped transactions. EMV transactions are subject to other rules. True/False allowed.	True
GetSignature	No	Manually prompts for signature post transaction.	string MySignature = TransRequest.GetSignature();

---

Receipt

Name	Required	Description	Sample Data
Settings.Printer_Name	No	Sends the transaction receipt to the printer.	Adobe PDF
Settings.Receipt_Merchant_Disabled	No	To disable the merchant receipt, set this to True. True/False allowed.	True
Settings.Receipt_Customer_Disabled	No	To disable the customer receipt, set this to True. True/False allowed.	True

---

Stored Account

Name	Required	Description	Sample Data
EnableStoredAccount	No	Enables the stored account option. Card number and expiration date are required, and a token can also be used. True/False allowed.	True
StoredAccount_Message	No* Required if EnableStoredAccount is set to True	Displays the message to show on the form for the user to select the stored account.	StoredAccount_Message = “Alt + &W – Use Stored Card {1}”;
StoredAccount_CustomerPin	No	Asks the user for their account PIN. The PIN will be whatever value is set here.	StoredAccount_CustomerPin = “2222”

---

Additional Features

Name	Required	Description	Sample Data
EnableMultipleKeys	No	Enable multiple keys on a computer so Initialization will not be required when switching keys. True/False allowed.	True
EnableCashback	No	Prompts the user if they want cash back. True/False allowed.	True
ShowKeyPad	No	If the merchant’s system is touch enabled, set to True to display an on-screen keypad. True/False allowed.	True
EnableKeyedEntry	No	To disable keyed entry, set to False. True/False allowed.	True
ExitFormOnDeviceError	No	To return control to the calling application after any device error, set to True. True/False allowed.	True
EnableSilentMode	No	To enable silent mode and prevent the payment screen from showing, set to True. True/False allowed.	True
EnableAmountConfirmationPrompt	No	Prompts the user to confirm the transaction amount. True/False allowed.	True

Transaction Types

See kb.cardknox.com/api for more information about each command and required/optional fields.