Important: When developing websites or building apps with Blocks, use Velo service plugins.
As an additional fees calculation provider, you can integrate with Wix to allow merchants to request and use your services on their Wix sites. The additional fees you calculate are then included on the site's cart and checkout pages.
The integration is done via an app in the Wix App Market and by implementing the Additional Fees service plugin. After the app is installed on a site, Wix calls your service whenever the site needs to calculate additional fees for a transaction.
Using the service plugin, you can design your app to calculate various additional fees for the merchant's customers, including:
Learn more about service plugin extensions.
It's important to note that when Wix calls your implementation of the Calculate Additional Fees method, the app must return fees in the same currency as the Wix site. Extract the currency for a site from the request to ensure the correct currency is used in your calculation.