Which API can be used to update connection information in workbooks and data sources?

The Document API is the correct choice for updating connection information in workbooks and data sources. It allows users to modify the structure and content of Tableau files, such as workbooks and data sources, by providing programmatic access to the components within these files. With the Document API, you can open a Tableau workbook or data source, change connection details, and save the modified file. This ability to manipulate the internal properties of Tableau documents makes it particularly effective for tasks that involve altering connections or other specific settings.

In contrast, other APIs have different focuses. The REST API is primarily used for managing Tableau Server resources, allowing users to automate and interact with server-based functionalities, such as user and group management, but does not directly modify workbook structure. The Webhooks API is designed for event notifications rather than making changes to workbook content. Lastly, the Hyper API is intended for creating and managing Hyper files, which focus on the data storage aspect, rather than updating the metadata or connections in a workbook or data source.