How to Build POS Integration Flows

When you build integrations for different POS devices, there are three distinct types of credit card processing flows. Read on to better understand each integration method.

Credit Card Processing Flow 1

Payment Engine → Cardknox Gateway → Bank The credit card device is used to obtain card information, but the transaction flows from Payment Engine to the Cardknox Gateway and then to the bank.

1. The POS software communicates the intended transaction to Payment Engine.

2. Payment Engine prompts the user for their card information via the credit card device.

3. The credit card device transfers transaction data to Payment Engine.

4. Payment Engine transfers transaction data to the Cardknox gateway.

5. The Cardknox gateway transfers transaction data to the bank for processing.

6. The bank communicates the transaction response (approval or decline) to the Cardknox gateway.

7. The Cardknox gateway communicates the bank’s transaction response to Payment Engine.

8. Payment Engine communicates the bank's transaction response to the POS software.

Credit Card Processing Flow 2

Payment Engine → Credit Card Device → Cardknox Gateway → Bank The credit card device plays an active role in the transaction flow, with the transaction passing from Payment Engine, to the device, to the Cardknox Gateway, and then to the bank.

1. The POS software communicates the intended transaction to Payment Engine.

2. Payment Engine communicates the intended transaction to the credit card device.

3. The credit card device prompts the user for their card information.

4. The credit card device transfers transaction data to the Cardknox gateway.

5. The Cardknox gateway transfers transaction data to the bank for processing.

6. The bank communicates the transaction response (approval or decline) to the Cardknox gateway.

7. The Cardknox gateway communicates the bank’s transaction response to the credit card device.

8. The credit card device communicates the bank’s transaction response to Payment Engine.

9. Payment Engine communicates the bank’s transaction response to the POS software.

Credit Card Processing Flow 3

Payment Engine → Credit Card Device → Bank The transaction flows directly from Payment Engine to the credit card device and then to the bank. As in the first two flows, Cardknox is still involved in the reporting and integration processes.

1. The POS software communicates the intended transaction to Payment Engine.

2. Payment Engine communicates the intended transaction to the credit card device.

3. The credit card device prompts the user for their card information.

4. The credit card device transfers transaction data to the bank for processing.

5. The bank communicates the transaction response (approval or decline) to the credit card device.

6. The credit card device provides the bank’s transaction response to Payment Engine.

7. Payment Engine communicates the bank's transaction response to the POS software.

8. Payment Engine notifies the Cardknox gateway of the transaction so that the data is recorded in the Merchant’s Cardknox account.

Ways to Integrate – Considerations

SDK (Payment Engine)

https://kb.cardknox.com/payment-engine-sdk/

Supported devices:

• All Cardknox supported devices

Benefits:

• Supports all Cardknox devices

Limitations:

• Only supported on Windows

BBPOS

https://kb.cardknox.com/bbpos/

Supported devices:

• All Cardknox supported devices

Benefits:

• Supports all Cardknox devices

Limitations:

• Only supported on Windows and Mac (The installation on Mac can be difficult)

• Requires the BBPOS application to be installed and needs to run in the background all the time

API + Keyboard Emulator

https://kb.cardknox.com/api/

Supported devices:

• ID Tech Augusta and VP8300

Benefits:

• Minimal integration

• Plug n Play Devices

Limitations:

• Supports a limited number of devices

• Does not support PIN entry

• Augusta does not support tap

• The US Only