What is API and how it works?

Simply put, an API (Application Programming Interface) is needed to share data between two different systems. In other words, an API is a messenger between two applications, e.g. an online store and accounting software. For example, it would be necessary for orders from the e-shop to be delivered to the accounting software, where the invoice is prepared, after which the response about the store update is sent back to the online shop.

In a broader sense, the API “bridge” is used daily to exchange various data around us (bus times, phone apps, ATMs, etc). A separate key (password) is needed to communicate between the two systems, which “opens the door” for data sharing.

How does an API work in SimplBooks software?

Basically, there are two options for using interfaces: 1) internal interfaces for SimplBooks (an API (Premium plan) is not required), and 2) external interfaces for SimplBooks (an API (Premium plan) required). So, internal interfaces for SimplBooks can be used without an API service, e.g they include online commerce solutions (WooCommerce + WordPress, Prestashop, Shopify), e-invoice operators (Envoice, Telema, Finbite), banks (SEB, LHV, Swedbank), EMTA (Estonian Tax and Customs Board, for VAT-declaration) and CostPocket for managing expenses (receipts and invoices).

External interfaces for SimplBooks require the use of an API (only in Premium plan). External interfaces are, for example, a WordPress plugin, or a personalized interface outside of SimplBooks software. For WordPress (WooCommerce), a readymade external interface is provided, for example, by E-liides.ee or YesItWorks. In both cases, it’s a third-party service provider that will sell you an applicable interface; and SimplBooks is not responsible for the interface or its operation. If you need a personalized interface with another online store or program, you must create it yourself or order it. SimplBooks doesn’t provide a service for creating a personalized external interface.