I tried to get this working but it appears Google is in the process of migrating their Next Developers sites to a new model and it is no longer possible (at least in trying to navigate their site) to sign up for a new developers account with the existing model.
This is the link to the Next package with the instructions detailed on how to add Next control to HomeGenie. Using the links in the instructions to try and add a new Product just keeps bringing you to the same page about the new model info, which is not slated to be released until nest year (2020) - not sure if even when that is released if the current widget and login stuff will continue to work.
I’ve noticed this PR from Home Assistant so based on that info the HG author would need to follow suit to get Nest support working again in HG
New users are not currently able to set up a Works With Nest Developer account due to the change announced by Google. We will reach out to Nest to see if we can become a partner so that users joining Home Assistant after August can still use Nest. In the future we will add documentation on how to setup a Works With Google account and configure your Nest integration.
So I was able to use the new Google api (there was a good YouTube video I found to help walk thru the steps) and I can make api calls to get the current data from the thermostat using Postman (an API testing tool).
However, I’m not all that experienced with C# and the HomeGenie Programs to make api calls (this needs to also use access tokens, which get generated as part of the setup).
I’m really only interested in getting the current temperature and humidity from the thermostat, so will try and play around with that now.
If you arent familiar with C based codes and need to learn a language, I’d recommend Python. It is very widely used and works on all platforms (windows, mac, linux, etc). C codes are great but Python is likely easier to get into and just as powerful for scripting type activities.