Square

Business

Visit website

Easy way to take payments, manage refunds, and help customers checkout online.

About Square

Square provides a developer platform with APIs and SDKs for building integrations with Square seller accounts. The platform covers payments processing (including refunds, disputes, checkout, subscriptions, invoices, and Terminal integration), commerce functions (orders, catalog, inventory, bookings, and vendor management), customer relationship management (customer profiles, groups, segments, and loyalty programs), staff management (labor tracking and team rosters), and merchant/location administration.

The reference documentation includes OAuth for delegated account access, webhook subscription management, and an events search feature. It is intended for developers building custom integrations for their own businesses, publishing applications in the Square App Marketplace, or working directly with Square sellers to extend or customize Square's point-of-sale and online store functionality.

Key features

Take payments, process refunds, and manage disputes via the Payments API
Pre-built Square-hosted Checkout page requiring no frontend
Catalog, inventory, and order management for sellers' products and services
Bookings API for creating and managing appointments
Loyalty programs, gift cards, and customer profile/CRM management
OAuth and webhook subscriptions for secure delegated account access

Frequently asked questions

What can I build with the Square API?

You can take payments, process refunds and disputes, manage catalogs and inventory, handle bookings, and manage customers, loyalty, and gift cards. It also supports staff, merchant, and location management.

Do I need to build my own checkout UI?

No, the Checkout API lets you accept payments through a pre-built, Square-hosted checkout page with no frontend required.

Does Square support in-person payments and hardware integration?

Yes, the Terminal API requests checkouts from a paired Square Terminal, and the Devices API creates device codes to connect Square Terminal with a third-party point of sale system.

Who is the Square API for?

It's for developers customizing Square for their own business, publishing apps in the Square App Marketplace, or building integrations for Square sellers.