POS API for Developers | Square

Point of Sale API, Square’s POS API, is ideal for developers who want to build a custom point-of-sale solution for in-person payments. Our POS API allows you to integrate the Square payments flow (and utilize our beautifully designed card readers) into a customized POS that suits your business’s unique needs.

Square’s POS API is perfect for businesses that want to build upon the out-of-the-box capabilities of our Square Point of Sale app. For example, custom furniture stores might need complex order forms for customized item specs. Museums and events sometimes have custom ticketing requirements and payments. Professional services might need custom order management workflows such as assessment and delivery dates. In all these cases, developers can create a customized POS app that integrates easily with Square’s POS API to take care of the payment flow process. Jobber and Breezeworks, for example, are all apps that have integrated with our POS API to take in-person payments.

Whatever your business, if you need a POS system that’s perfectly tailored to your unique needs, Square’s POS API offers you fully integrated payment processing without having to build your own payment flow from scratch. Our standard Point of Sale app is a powerful tool that allows millions of merchants to run their businesses from top to bottom. By using our POS API, you get access to all these tools along with the workflows you need in your specialized POS app. You’re able to view all your transactions in Square’s online Dashboard and take advantage of all the reporting and analytics you get from selling with Square. Our point-of-sale API is fully PCI compliant, our fees are competitive, and our sellers get paid fast.

Why we made our POS API

We started our payments company so anyone anywhere could take credit and debit card payments. Creating our POS integration API is a continuation of that mission. We’ve built a really solid payments infrastructure and want to allow people to build on top of it. Our POS API is a great way to support businesses that have more complicated POS needs than what we’re able to provide with our standard offering.

How does the point-of-sale (POS) API work?

Our POS integration API uses an app switch, meaning the app switches between your custom POS and Square’s Point of Sale app to process a payment. With just a few lines of code, you’re ready to initiate a transaction from your POS. Once initiated, it automatically switches you into the Point of Sale app. There you can swipe or dip cards, or tap devices for NFC payments. After the payment flow, the app switches back to your custom POS. It’s simple and easy.

What POS features can I expect?

  • Quick, easy API integration
  • Cutting-edge hardware that accepts EMV chip cards, debit cards, contactless (NFC) payments including Apple Pay
  • PCI-compliant payments
  • Quick deposits: merchants see payments in their bank accounts in one to two business days
  • Offline payments*

Offline payments are processed automatically when your device regains connectivity, and will expire if not processed within 24 hours. By enabling Offline payments, you’re responsible for any expired, declined, or disputed payments accepted while offline.

How much do payments with Square’s POS API cost?

Payments made with Square’s point-of-sale API are charged at Square’s standard rates. It’s just 2.65% per swipe, insert, or NFC payment. Manually entered transactions are charged at 3.4% + 15¢. Rest assured, there are no monthly fees or long-term commitments. It’s always free to integrate Square’s POS API into your software.

Square’s POS API facilitates PCI-DSS compliant payment processing

PCI compliance can be a real headache for developers. The PCI Security Council’s stringent requirements are set up to make sure all companies accept, process, store, and transmit credit card information safely. Which is really important but can be a lot to take on for developers who aren’t payments experts. Fortunately, Square takes on the burden of staying PCI compliant. No checklists, assessments, or audits required. Whether you use Square’s Point of Sale app or our POS API, you’re good to go and don’t have to worry about checklists.

Get started with the Square POS API today.

Payment processing made easy.


Is Square’s POS API right for me?

Square’s Point-of-Sale API is a payments API that’s appropriate for in-person payments. To take online payments, check out our E-Commerce API, or create your online store with Weebly. If you’re building your own POS app, you can use Square’s POS API to take care of payments. Our point-of-sale API triggers an app switch that takes the merchant from your custom app to Square Point of Sale to complete the transaction.

API Best for:
E-Commerce API Online payments and custom e-commerce stores, payment processing, and customer management
Point-of-sale API In-person payments, custom point-of-sale (POS) applications
Items API Item and inventory management
Reporting API Sales reporting and analytics
Employee Management API Managing employee roles and permissions, including easy management of hours worked across locations
Other APIs Managing customer data, managing online stores, and tracking inventory

What makes Square’s POS API the best way to accept in-person payments?
Square’s POS API is fast to integrate with just a few lines of code. It facilitates PCI-DDS compliant payment processing because credit card information never hits your app. And Square has great hardware that’s simple, stylish, and secure.

What currency are sales processed in?
Sales on Square’s POS API are made in Canadian dollars.

Does Square’s POS API deposit cash using ACH payments?
Yes, our POS API integration deposits sellers’ payments into their bank account using ACH payments. Payments are fast and secure, and are deposited in one to two business days. If your business has unique hours, you can customize the time you’d like transactions grouped for daily deposit by editing your Close of Day.

Do I still need a payment gateway with Square APIs?
No, you don’t need a payment gateway or merchant account when you use Square’s Payment APIs. All you need to start selling with Square is a Canadian chequing account and a free Square account. It takes just a couple of minutes to sign up for a Square account and no credit check is needed.

Where can I find more information about POS integration/API documentation?
There are more resources on the Square website for developers interested in learning about POS API integration and API documentation.

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