Scripting Retrobatch From the Command-Line
You can call Retrobatch from the command line, with arguments for a workflow, output folder, and images / folder to process. Call the Retrobatch tool from within the Retrobatch app (which is likely in your Applications folder) as follows:
/Applications/Retrobatch.app/Contents/MacOS/Retrobatch --workflow path/to/workflow.retrobatch --output ~/Desktop/foo/ /path/to/files.jpeg /or/folders/
Note for the App Store version of Retrobatch.
If you are using the App Store version of Retrobatch, you may encounter problems with the command line tool unless you give Retrobatch Full Disk Access in the System Preferences.