What API should be used for backing up files such as attachments and documents?

The REST API is the correct choice for backing up files such as attachments and documents in Salesforce. This API is designed for working with a wide range of resources, including standard and custom objects, which encompass attachments and document files.

One of the key advantages of using the REST API is its simplicity and ease of use with modern web standards, making it suitable for applications that require quick and efficient data retrieval or manipulation. It utilizes a stateless communication model, allowing for efficient file transfers over HTTP, which is particularly helpful when working with large files.

Additionally, the REST API provides endpoints specifically for accessing attachments and documents in Salesforce, allowing developers to easily retrieve and backup these types of files. Its HTTP-based architecture also integrates well with many programming languages and platforms, facilitating smoother development processes when backing up files.

Using other APIs like the Bulk API would not be ideal for this scenario, as it is primarily aimed at handling large volumes of records efficiently during data import and export processes. The SOAP API, while capable of managing attachments, is more complex and less efficient for simple file transactions compared to the REST API. The Metadata API is primarily intended for managing customization and configuration metadata, which does not include real file content. Therefore, for backing up files like attachments