Which API is used to connect to data sources and write data into extract files?

The Hyper API is designed specifically to interact with Tableau's Hyper format, which is used for creating, updating, and writing data into extract files. This API enables developers to programmatically access and manipulate data in Hyper files, making it an essential tool for tasks such as creating data extracts from various data sources and writing them in a way that Tableau can efficiently visualize and analyze.

In contrast, the other APIs serve different purposes. The Extensions API is focused on enhancing the capabilities of Tableau dashboards by allowing developers to create custom extensions that can interact with users or external data sources. The Metadata API allows users to programmatically access and manage information about Tableau resources and relationships, but it does not directly facilitate writing data into extract files. The Document API is used to manage Tableau document formats, such as workbooks, but it does not handle data extraction or writing directly into Hyper files. This distinction highlights why the Hyper API is the correct choice for connecting to data sources and writing data into extract files.