@andrewteg I'm not sure if you're asking if you can create a primary key or type serial: yes you can, Use Data type: Serial and Index: Primary Key
Or if you're asking about a dynamic workspace - see this recent post: https://knowledge.safe.com/questions/104765/append-multiple-esri-geodatabases-into-one.html?childToView=104770#answer-104770 File Geodb, but same steps.
For a dynamic workflow, you can append the shape files to the same PostGIS table or have separate tables for each Shape file.
But... if you want to add an attribute to a dynamic workflow, then add an attribute to the writer feature type, then that attribute will get added to all the output tables that the dynamic workflow creates
I've attached a workspace that illustrates how this works: serialprimarykey.fmwt
Thanks, I did see that Serial and Primary Key would create what I needed, but I was using Manual over dynamic. I'll have to give dynamic a shot and see how that works as I'm hoping to convert a few hundred shape files overall and looking for any shortcuts I can find!