The big announcement at Google I/O ‘19 is that Google is discontinuing the Works with Nest API program. Nest is the only no-local-control ecosystem I have in my house, and it was so very clearly a mistake in hindsight. In order for an end user to integrate Nest with a third party product like Home Assistant, one needs a developer account. Right off the bat, Nest assumed that the only people who would want to do such a thing is other cloud-based services like Hue, or Amazon who would interact with Nest on behalf of a user, rather than a user themselves.
I currently have a developer account, and I use it with Home Assistant to do a number of automations tied to my Nest devices. There’s a lot of customized control over when the HVAC goes into away (eco) or home mode based on the arrival and departure - or expected arrival - of my home’s residents. More interestingly, a number of automations around Nest Protect enhance the safety of my home by unlocking the doors if people are home, turning on lights, and disabling the HVAC system in the event of an incident.
None of these would be possible if Nest shuts down the Works with Nest program, other than whatever specific partner integrations they allow. This is all in the name of “privacy,” which in Google’s mind is that your private information is only known by you and Google. Why, then, have they not assauged the hobbyist communitys concerns by announcing a local API option?
The protocols that Nest devices use are open source-ish, called Weave and Thread. Certainly they could open them up to allow me to control my own devices. Anyway, even if Google eventually figures it out and does the right not-evil thing, I figured I should look at alternatives.
For now, I’ve already replaced my thermostat with a Venstar ColorTouch T7850. It features a local API, and a home assistant component.
It’s not as pretty as a Nest’s round, sleek appearance but it’s works well and has full local control. The Nest Protects’ most likely replacement is a Z-wave device from First Alert, but for now I’ve kept them. I do like their voice announcements of the problem - in Spanish and English - and the pathlight feature when one walks down the hallway at night.