I assume you may have expected writing some code to register your data directly to AYON. Actually such lives in the integrate plugin.
However, it’d need converting this plugin into a library to have a Publish API.
Currently, we should stick to pyblish workflow, once you are inside a host, you can either use the publisher tool ui or from code to create instances, then publish them.
It’s worth mentioning that this tool exists AYON Batch Ingest Tools