.NET SDK

Overview

The .NET Payment Engine SDK provides an easy way for developers to integrate card-present and card-not-present payment processing into their .NET projects. Our SDK is designed with user-friendly payment functions and compatibility with a broad range of payment hardware, removing the need for complicated device integration. With this SDK, you can easily incorporate its advanced payment processing capabilities into your .NET projects, streamlining your payment processing experience.

Getting Started

To get started with the SDK, you need to include the following DLLs in your project: PaymentEngine, xCore, xCore.Forms, NLog, and Newtonsoft.Json.

Click Here to Download SDK Files

Initiate Transaction

Initiating a transaction requires the selection of either the "in-scope" method (Process) or the "out-of-scope" method (ProcessOutOfScope). Before starting the transaction, ensure that all required and optional parameters have been properly set as outlined in the documentation.

Out-of-Scope (ProcessOutOfScope)

Use the out-of-scope transaction method when the user needs to provide their credit card information. In this case, the SDK will handle the process of collecting the sensitive credit card data from the user through a pop-up window or a credit card device, and then processing the transaction with the payment gateway.

In-Scope (Process)

Use the in-scope transaction method when there is no need for the SDK to interact with the user. This could be when you have already obtained the card number or when you want to run a void, for example. When using this method, you cannot set any parameters specific to a device.

Transaction Workflow

Click here to view the transaction workflows.

Download Our Sample Application Our sample application supports some of the basic transaction workflows; more will be added in the future. The application is intended to show you how our SDK works.

Transaction Functions

Function	Description	Sample Data
ProcessOutOfScope	Process an out-of-scope transaction	ProcessOutOfScope();
Process	Process an in-scope transaction	Process();

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	Cardknox transaction type	cc:Sale
xAmount	Yes	Total amount of the transaction, including tax and tip, if applicable.	3.0
xTax	No	Tax amount of the transaction. The xTax amount is included in the xAmount.
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
EnableTipPrompt	No	Prompts the user on the device to add a tip to the transaction. This functionality is only available when the device is enabled. The response to the transaction will include two parameters: "xTip" (the tip amount) and "xAuthAmount" (the final authorized amount on the card, including the tip amount).	True
TipPromptOption	No	To configure the tip percentage options shown to the user when the "EnableTipPrompt" feature is enabled, you can use the "TipPromptOption" setting. You can specify four options, separated by commas. You may include a “c” as one of the options, which allows the user to enter a custom tip amount when selecting that option and/or “0“ to have a “No Tip“ option as well. For example, if you want to show tip options of 5%, 10%, 20%, and a custom amount, you can set the "Tip Prompt Option" as "5,10,20,c". This will present these four options to the user when they are prompted to add a tip to the transaction.	5,10,20,0

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
Form_Timeout	No	Sets the number of milliseconds that the request should time out after. This should typically be set to at least 2 minutes (120,000) so it does not interrupt a transaction in progress.	120000
Form_BackColor	No	Set form background color	Drawing.Color.Agua
Form_Height	No	Set form height	500
Form_Width	No	Set form width	500

Device Settings

Device Name

Pax devices start with Pax_ and end with .3 (example: Pax_s300.3) S300 S920 A60 A80 A920 PX5 PX7 D210 D220

Verifone devices start with Verifone_ and end with .4 (example: Verifone_MX915.4) P400 P200 M400 E285 MX915 MX925 VX805 MX850 MX860 MX870 MX880

VeriFone driver download: https://cdn.cardknox.com/pe/files/verifone_unified_driver_installer-5.0.5.2-b5.zip

Ingenico ISC and IPP devices start with Ingenico_ and end with .6 (example: Ingenico_iSC480.6) IPP320 IPP350 ISC250 ISC350

Ingenico ICT and Tetra devices start with Ingenico_ and end with .2 (example: Ingenico_iCT250.2) ICT250 Desk5000 Move5000

ID TECH devices start with IDTech_ and end with .12 (example: IDTech_VP6300.12) VP6300 VP6800

USB These settings should match what is set for the device in device manager:

COM Port (default: COM9) Baud rate (default: 115200) Parity (default: N) Data Bits (default: 8)

IP These settings should match what the device is set to.

IP Port Port (default: pax10009 verifone9001 ingenico9999)

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”
EnableDeviceKeyedEntry	No	Allows the user to key in their card number on the credit card device. EnableDeviceInsertSwipeTap cannot be set to True in the same request.	True
ShowMenu_DeviceKeyedEntry	No	Adds the DeviceKeyedEntry option on the form for the cashier to toggle.	True

Cancel Command

Name	Description	Sample Data
Cancel()	Cancel ongoing function	Cancel("Transaction canceled")

PIN Signature

Name	Description	Sample Data
EnableDeviceSignature	Prompt for signature after the transaction is approved. True/False allowed.	True
EnableDeviceSignature_MinAmount	Prompt for signature only if xAmount is greater than the amount set here. EnableDeviceSignature must be set.	5
EnableDevicePin	Set the device to prompt for a PIN on swiped transactions. EMV transactions are subject to other rules. True/False allowed.	True
GetSignature	Manually prompts for signature post transaction.	string MySignature = TransRequest.GetSignature();
GetSignatureAndSaveToFile	Manually prompts for signature post transaction and saves it to a file. You can pass through a string to display a message when prompting.	string MySignature = TransRequest.GetSignatureAndSaveToFile(“Signature.png”);

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”

Show Items

This is currently only supported for the Mx915 and Mx925. You can add xAmount and xTax to the request before “Device_ShowItems“ so the user can see the total amount and tax of their order. This runs on a separate thread within the application.

Name	Description	Sample Data
UpdateItems	Specify the items to show during the transaction (JSON or XML).	TransRequest.UpdateItems(“json”, “[{‘xdescription’:’ItemABC’,’xupc’:558,’xqty’:3,’xunit’:’EA’,’xunitprice’:’5.99′}]”);
Device_ShowItems	Show the items that were specified in “UpdateItems”.	TransRequest.Device_ShowItems();

Update Device

This is currently only supported on certain VeriFone devices.

Name	Required	Description	Sample Data
Device_OsUpdateAvailable	No	Checks if there is an available device OS update.	bool OsUpdateAvailable = TransRequest.Device_OsUpdateAvailable();
Device_UpdateOS	No	Update the device OS.	Device_UpdateOS();
Device_FirmwareUpdateAvailable	No	Checks if there is an available device Firmware update.	bool FirmwareUpdateAvailable = TransRequest.Device_FirmwareUpdateAvailable();
Device_UpdateFirmware	No	Update the device Firmware.	Device_UpdateFirmware();

Additional Features

Name	Required	Description	Sample Data
EnableMultipleKeys	No	Enable multiple keys on a computer so that 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

Show Forms

This is currently only supported on certain Verifone devices.

Name	Description	Sample Data
Device_ShowMessage	Show form with message of up to 4 lines. An exception will be thrown if the device does not support it.	Device_ShowMessage(“Hello” ,”Welcome”,”Cardknox”,”Thank you!”);
Device_TryShowMessage	Show form with message of up to 4 lines. This returns a boolean indicating if it was successful or not.	Device_TryShowMessage(“Hello” ,”Welcome”,”Cardknox”,”Thank you!”);
Device_ShowWelcomeScreen	Show the welcome screen on the device. An exception will be thrown if the device does not support it.	Device_ShowWelcomeScreen();
Device_TryShowWelcomeScreen	Show the welcome screen on the device. This returns a boolean indicating if it was successful or not.	Device_TryShowWelcomeScreen();
Device_PromptForEmail	Prompt the user for their email address.	Device_PromptForEmail();
Device_PromptForPhone_JSON	Prompt the user for their phone number.	Device_PromptForPhone_JSON();
Device_PromptForZip	Prompt the user for their ZIP code.	Device_PromptForZip();

Response Parameters

Transactions that are submitted through the SDK will return a response with one or more fields. Most can be found at https://kb.cardknox.com/api/#_Response_Parameters . Below are the parameters that are specific to the SDK.

Field Name	Description	Values
xIsDebit	Indicates if the transaction was processed as debit.	True/False

Sandbox Account Test Cases

Most test cases can be found at https://kb.cardknox.com/api/#_Sandbox_Account_Test_Cases . Below are the test cases specific to the SDK.

Triggers

Debit transaction Use the cc:sale workflow and set EnableDevicePin = True. Insert a debit card into the device and it will prompt you for the PIN (If prompted for AIDs, on the device select the Debit AID); you can enter any PIN. The transaction response will include xIsDebit = True.

Offline transaction

The SDK allows you to process transactions when your system is offline. The idea is that you, the user, will insert/enter their card and you will receive an encrypted token to be used when the system is back online. See the cc:encrypt workflow.