With Square APIs and SDKs, it’s Square — customized.

Supercharge Square for sellers of every size. Our entire connected commerce platform – from elegant hardware to a rich suite of Square APIs – is yours to build with. Whether you’re developing an app or composing a bespoke solution, this is the place to make it happen.

< Manage clients. =

Sync, save, and support all sorts of customer details to streamline bookings and appointments, to build loyalty programs, to sell gift cards, to offer discount codes, and more.

Most popular APIs and tools for customer engagement:

< Analyze data. =

Pull metrics, pay taxes, and keep your books in order with APIs and endpoints that allow users to monitor the health of their businesses.

Most popular APIs and tools for visualizing data:

< Sell everywhere. =

Whether customers are strolling — or scrolling — through your store, you can build a payment solution to meet them wherever they shop.

Most popular APIs for seamless selling and payment integrations:

< Deliver orders. =

Bring order to your logistical flow with APIs that can manage purchases and deliveries; inventory updates; and your locations, vendors, and merchants.

Most popular APIs for smooth deliveries:

< Move money. =

Manage your banking operations and transfer money directly between accounts.

Most popular APIs for making money move:

< Get creative. =

There’s so much you can do with over 20 Square APIs and 100+ endpoints. Connect them this way, that way — your way — to create your commerce solution.

We can’t wait to see what you’ll build:

  1. Omnichannel checkout

  2. Restaurant kiosks

  3. Spa booking software

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Build it your way with the tools you need and the tech you love.

Square backend SDKs

Develop in Python, Node.js, Ruby, PHP, Java, and .NET.

PD06703 - Square Backend SDKs - python

PD06703 - Square Backend SDKs - nodejs

PD06703 - Square Backend SDKs - ruby

PD06703 - Square Backend SDKs - php

PD06703 - Square Backend SDKs - Java

PD06703 - Square Backend SDKs - dotNet

API Explorer, GraphQL Explorer, and Connect Postman

Explore endpoints, test your integration, send http requests, and more with a trio of tools designed to help you validate your build.

API logs

View, search, and filter your log entries for diagnostics, troubleshooting, and auditing. 

Webhooks, event logs, and subscriptions

Get notifications about your application(s) with in-depth webhooks features.

Square sample applications

Experiment with OAuth, Square SDKs, GraphQL, and mobile.

Compose your app or integration with a robust suite of Square APIs and developer resources.

Payment APIs and SDKs

Give sellers the flexibility to process online, in-person, and in-app transactions.

Go to payments docs ->

Commerce APIs

Allow sellers to process orders, to manage catalogs, to track inventory, to book reservations, and to customize Square Online. 

Go to commerce docs ->

Customer APIs

Create a path for sellers to grow relationships by integrating customer, loyalty, and gift card features directly into your application.

Go to customers docs ->

Staff APIs

Ensure sellers can compensate their employees and schedule staff with team management and recording tools.

Go to staff docs ->

Merchant APIs

Support sellers as they leverage the Square platform across all aspects of their businesses and across multiple locations.

Go to merchants docs ->

It’s all happening on the Square platform.

Q&A: Discover what’s new in the Mobile Payments SDK beta.

Now on the blog

Sandbox 101: End-to-end payments with Web Payments SDK

Video tutorial

Learn how Towbook evolved their towing software business with Square.

Dev Spotlight

Unlock a better mobile experience with GraphQL and PKCE.

Now on the blog

See how Reference Health uses Square APIs in the health care space.

Dev spotlight


Build and grow your own business with Square.

Partner with us to help businesses crush it — yours included. Get resources to create solutions, find customers, and scale up and up and up. Once you’ve built your app or integration on the Square platform, join the partner program that’s right for you:

Publish in the Square App Marketplace as an app partner.

Work one-on-one with sellers as a solutions partner.

Refer businesses to Square as a referral partner.

What’s your move?