Basics of Building Applications with Square

In the Get Started exercise, you create a Square account, explore the Seller Dashboard and Developer Dashboard, and test a Square API in the Square Sandbox environment.

Now that you are ready to explore sample applications or create your own application, this section provides topics that explain some of the common concepts useful in application development. For example, to build great applications with the Square APIs and SDKs, you should learn about the basic design principles that form the foundation of Square APIs. These principles include the API versioning scheme, secured access, and the Square API lifecycle.

General development considerations

• Frontend versus Backend. A typical application has a frontend (client component) and a backend (server component). Square provides API libraries that developers embed when developing an application frontend and backend.

• TLS and HTTPS. HTTPS is required for all API calls to Square endpoints. This topic provides initial guidance for enabling HTTPS on your website.

• Using the REST API. The Square API follows the general patterns of REST. This topic provides introductory information about creating HTTPS requests and handling the responses.

• Handling errors. Square APIs always return a response. This topic explains the Error object structure, which helps you process responses when using SDK libraries.

• Collecting information. If you collect, or plan to collect, personal information from customers, it is critical that you handle that information responsibly. This topic provides general guidelines for collecting and managing such information.

• Language preferences. People communicate with software through natural languages, such as English, French, and Spanish. Because each person has a different preferred language, developers must track and accommodate language preferences of customers. This topic explains how applications that integrate the Square API might accommodate these language preferences in communications.

Common data types

The following topics explain commonly used Square data types:

• Working with Dates

• Working with Monetary Amounts

• Working with Addresses

Common Square API patterns

The following topics explain API patterns that are common across Square APIs:

• Idempotency

• Pagination

• Optimistic concurrency