Square Connect API

Develop with Square.

The Square Connect API enables you to build apps for millions of Square merchants—or a custom solution for just one.

Manage Apps Get Started

A marketplace for millions of merchants

Get your app out there.

Put your work in front of millions of business owners when you list in the Square App Marketplace.

Get discovered with a click.

Put yourself one click away from a merchant with our seamless onboarding.

Get paid automatically.

No need to worry about chasing down a payment or setting up your own billing system. Get paid with Square’s billing system and subscription APIs.

Apply to the Square developer program

Square serves millions of merchants. Apply to grow your business by building with the Square Connect API and publishing in the App Marketplace.

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    Build out your application using Square’s Connect API. Submit your app idea for initial approval by emailing us at developers@squareup.com to get started.

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    Your integration will need to be tested with real Square merchants before being accepted in the App Marketplace. Beta test your application with up to 10 Square merchants.

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    Implement App Marketplace seamless sign-up process and, if you plan on charging for your application, implement Subscriptions API to facilitate charging merchants.

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    Get Approved

    Submit your applications including a test account and beta merchant information for approval. Prepare your App Marketplace listing.