Square Terminal Integration Overview
Use the Devices API to pair a custom point-of-sale (POS) application with a Square Terminal and the Terminal API to take in-person payments with payment cards on the paired terminal.
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The Terminal and Devices APIs let developers integrate Square in-person payments in all supported areas and Canadian Interac refunds in custom POS applications using a Square Terminal which supports authorization and payment processing. The Square Terminal simplifies chip and NFC payments, addresses EMV certification requirements, and makes PCI compliance easy.
Terminal API is available in Australia, Canada, Japan, the United Kingdom, and the United States.
A POS client cannot be physically connected to a Square Terminal but must be paired using the API and a wireless internet connection before a checkout can be processed.
The Devices API can pair a POS client with a Square Terminal as long as the terminal is wirelessly connected to Square. The API lets the POS request a pairing and a returns a device code for use by the seller. The request is sent to Square and then Square directly connects to the Terminal using the wireless connection. Once the connection is made, Square sends the device code back to the POS.
The seller uses the device code to sign in to a Square Terminal. After the seller signs in, the Devices API returns the unique ID of the terminal as a
DeviceCode.device_id. The ID is used in later terminal checkout requests. The Devices API DeviceCode object represents a POS client/Square Terminal pairing. It contains the sign-in code, pairing status, and device ID of the Square Terminal.
When the Square Terminal is paired, the POS client can send checkout requests using the Terminal API. The Square Terminal uses the wireless connection with Square to get payment information from the request and collect the payment from the buyer.
You can see the device paring state on the Seller Dashboard by choosing Accounts & Settings, and then choosing Devices.
Whether accessed through the Devices API or the Seller Dashboard, the
DeviceCode object represents whether the device code has been used to sign into a Terminal device. It does not represent the current status of the device.
A POS application sends a request to check out a buyer on a paired Square Terminal by using the Terminal API. The terminal checkout request goes to Square, which forwards it to the paired Square Terminal. The request carries the total amount to collect and the expected Square Terminal payment screen behavior.
Use a Terminal API checkout request to set Square Terminal behavior per checkout request. Customizable behaviors include:
Skipping the receipt screen.
Showing a separate tip input screen before getting a buyer's signature.
Allowing custom tip amounts.
The Terminal API lets a POS client set payment completion options per checkout.
When the buyer completes the checkout on the Square Terminal, the POS application can be notified by a Square webhook. If the POS application is not listening for webhook notifications, it can get the checkout result using the Terminal API.
A POS application can get a history of checkout requests and results filtered by Terminal device ID, time range, and checkout status.
Checkouts in either the COMPLETED or CANCELED states are DELETED after 30 days. The Payment object serves as your permanent record.
The Terminal API supports payment cards, and NFC payments like Apple Pay and Google Pay. Payment cards include Square Gift Cards, credit cards, debit cards, and prepaid debit cards. In Japan, E-money card payments are also accepted. Square Terminal does not support cash payments.
To learn more, see Supported Payment Cards by Country.
Did you know?
The Terminal API does not support payments split across multiple payment cards. If multiple payments are needed, you can create a checkout for each partial payment.
Your POS application should monitor the state of any terminal checkout requests. It can do this by periodic Terminal API calls to get the current state of a Terminal checkout. To avoid adding this polling behavior, your application can use the webhook notifications provided by the Terminal API. These notifications are posted to the listening endpoint that your configure whenever a checkout is created or updated.