Can I use a commandline interface with Scribus?

Can I use a command line interface with Scribus?
Or: I can call Scribus as part of an external script?

Short answer: No, not at this time.

Long answer: You cannot directly call Scribus. However, you can use Scribus to build templates. The Scribus .sla file type is XML (tagged plain-text) and can be processed with nearly any CLI converter out there.