Which API is responsible for sending an SMS upon data source refresh?

The Webhooks API is specifically designed to send notifications based on events, such as data source refreshes. This API allows Tableau Server or Tableau Online to send HTTP POST requests to a specified endpoint whenever a designated event occurs, which can include actions like data source refreshes. By utilizing webhooks, you can easily set up a system to trigger SMS notifications or any other types of alerts when specific events take place in your Tableau environment.

The other APIs serve different purposes; for instance, the Document API is used primarily for creating, manipulating, and managing Tableau document files. The Analytics Extensions API allows developers to integrate external analytics services into Tableau, enabling advanced analytical capabilities. The Extensions API facilitates the creation of interactive elements within Tableau dashboards but does not handle notifications or alerts directly. Hence, the Webhooks API stands out as the correct choice for sending SMS alerts upon data source refresh events.