[xrd]

Do you mean Firebase or Firestore?

If you mean Firestore, what about minio? It's incredibly scriptable and awesome.

If you mean Firebase, use rxdb and connect over graphql (hasura is fantastic) to your postgres database. It can be a little work to understand how the models all map into the database, but once you get it, it's magical.

Both are easy to self host. I run my entire stack of all components on dokku, so I get easy logging, backup, and can migrate to a new host in a few standard commands.