I think that meraki-sdk is the "official" release, though "merkai" that Shen has written will work as well.
meraki-sdk is based on the OpenAPI standard, and is what is documented on developer.cisco.com as you saw.
Keep in mind that there is going to be a lag between what gets committed to github (most current and up-to-date version), and auto generated in the docs and what is released on pypi.