Catalog.json creation without actual source credentials?

Take Marketo as an example. I see various json schemas under source_marketo/schemas/, e.g. leads.json etc. From my understanding, in order to generate dbt models, we need to have a catalog.json where each type of data is listed as a “stream” in the list of “streams”. It seems like it should be possible to create the “streams” list by inserting the json schema of each stream into the catalog.json.

I could be wrong, but it seems like the catalog.json should (mostly) not rely on having any credentials for the source. Please correct me if I am wrong, and otherwise can someone point me to the code that creates these catalog.json files?

Thanks

I think this is a duplicate question I already answered here: Docker-free commands to sync a source? - #5 by alafanechere