What type of data source should be built to accommodate direct data import from a source system through an API interface?

A Connector is the appropriate choice for accommodating direct data import from a source system through an API interface because it is specifically designed to facilitate automated data exchange between OneStream and external systems. Connectors allow for seamless integration by leveraging APIs to pull in data directly without the need for intermediate file formats. This capability supports real-time data updates and ensures that the data is synchronized efficiently between the source system and OneStream.

In contrast, a Delimited File is typically used for batch data uploads and requires that data be prepared as text files. Manual Input Files involve user-generated entries and do not support automation. A Database Source relies on a connection to a database but does not inherently provide the direct real-time interface that a Connector offers. Therefore, when dealing with APIs for direct data import, a Connector is the optimal solution.