I'm looking for a concise word or phrasing for "in a context without a user"? This is obviously in the context of software. More generally, what is a concise way of saying, "in a context without X (where X is usually assumed)?"
Over the years I've written various programs that originally were intended to be explicitly run by an actual human user, who would interact with the program to perform some task.
At some later time it may be useful to run such a program from a 'batch' file. Perhaps run at some configured 'slack' time when there is no user present, perhaps with a command-line option to specify exactly which task to perform, and how.
In such circumstances the program needs to know which 'mode' it's running in. For example, you can't just display an error message and wait for the user to select Cancel/Continue if there's nobody around to read it and respond.
My programs normally used a boolean flag unattended, set true if there was no user available to control progress (in which case the programs would perform some sensible default action as required).
In a software context we sometimes talk about running "headless" clients, as an alternative to running GUIs. I don't have a term that works in a non-software context.