We are backwards compatible on minor and patch releases, but not major releases. This is a major release 0.x->1.0. I don't think adding the database_id to the client api will hurt adoption. We just need to make it clear on the website where to get the database id. That is not the case right now but it is a very easy fix. Initially, the database_id and api_key will be the same. It gives us the flexibility to change this in the future, which is what we care about. 

With the required database_id param, no one will need to update their code when we release the multiple credentials feature.

This client will be rolled out as an official 1.0 release.