.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

Tax amount of the transaction. The xTax amount is included in the xAmount.

xAllowDuplicate

By default, Cardknox rejects duplicate transactions within 10 minutes of the original transaction. This command overrides that safeguard.

True/False allowed.

True

RequireAVS

Requires the user to enter their street address and ZIP Code (only affects keyed transactions).

True/False allowed.

True

RequireCVV

Requires the user to enter CVV (only affects keyed transactions).

True/False allowed.

True

EnableTipPrompt

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

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

Returns control to the calling application if the transaction is approved.

True/False allowed.

True

ExitFormIfNotApproved

Returns control to the calling application if the transaction is not approved.

True/False allowed.

True

ExitFormOnDeviceError

Returns control to the calling application after any device error.

True/False allowed.

True

Form_Timeout

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

Set form background color

Drawing.Color.Agua

Form_Height

Set form height

500

Form_Width

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

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

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

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.

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

Sends the transaction receipt to the printer.

Adobe PDF

Settings.Receipt_Merchant_Disabled

To disable the merchant receipt, set this to True.

True/False allowed.

True

Settings.Receipt_Customer_Disabled

To disable the customer receipt, set this to True.

True/False allowed.

True

Stored Account

Name

Required

Description

Sample Data

EnableStoredAccount

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

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

Checks if there is an available device OS update.

bool OsUpdateAvailable = TransRequest.Device_OsUpdateAvailable();

Device_UpdateOS

Update the device OS.

Device_UpdateOS();

Device_FirmwareUpdateAvailable

Checks if there is an available device Firmware update.

bool FirmwareUpdateAvailable = TransRequest.Device_FirmwareUpdateAvailable();

Device_UpdateFirmware

Update the device Firmware.

Device_UpdateFirmware();

Additional Features

Name

Required

Description

Sample Data

EnableMultipleKeys

Enable multiple keys on a computer so that Initialization will not be required when switching keys.

True/False allowed.

True

EnableCashback

Prompts the user if they want cash back.

True/False allowed.

True

ShowKeyPad

If the merchant’s system is touch enabled, set to True to display an on-screen keypad.

True/False allowed.

True

EnableKeyedEntry

To disable keyed entry, set to False.

True/False allowed.

True

ExitFormOnDeviceError

To return control to the calling application after any device error, set to True.

True/False allowed.

True

EnableSilentMode

To enable silent mode and prevent the payment screen from showing, set to True.

True/False allowed.

True

EnableAmountConfirmationPrompt

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://docs.cardknox.com/#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.

Troubleshooting steps

Ensure the Payment Engine DLLs are downloaded and referenced in the project. These include PaymentEngine, xCore, xCore.Forms, NLog, and Newtonsoft.Json.
Ensure that the Payment Engine DLLs architecture (x86, x64, AnyCPU) matches your project build settings.
Ensure that the Payment Engine DLLs .NET version matches your project framework version.

Last updated 19 days ago