The Nest Thermostat was invented in 2011 by Tony Fadell a former VP of the iPod division at Apple Inc. in 2014 Nest Labs was acquired by Google. Unfortunately, this means that Nest will probably never support HomeKit because Google wants you to buy into the Google ecosystem and purchase Android phones, they have no incentive to incorporate their products into the Apple ecosystem.
With the rivalry between Google and Apple making official HomeKit support unlikely, there is a product that bridges the gap between Nest and Homekit. The open source project HomeBridge will allow you to connect the Nest thermostat into the Apple Homekit application even when Google won’t support it. This is made possible by the developer API that Nest provides, You can quickly sign up for a developer account with your Nest login. Install the Homebridge application, then set up the HomeBridge Nest plugin and have your Nest Thermostat up and running in the Apple Home app on your iPhone or iPad.
HomeBridge is an open source software that was developed by Nick Farina This software has plugins that allow you to connect smart hardware into the Apple HomeKit application. Once completed you will be able to adjust the temperature, set it to home or away, and change the mode on the thermostat. To see the complete list of supported hardware with plugins to HomeBridge see this list HomeBridge plugins NPM page.
How do I get started with HomeBridge?
First, you will need to install the HomeBridge application on a machine that is always on. The software can be installed on any computer, PC or MAC. The best solution is to Install the software on a Raspberry Pi. A Raspberry Pi is a small Linux computer that only costs $35 and uses a small power draw so that it will not have a significant effect on your electric bill. To install on your Raspberry Pi you can follow these directions to prep your Raspberry Pi for the software Running HomeBridge on a Raspberry Pi. Once you have the Raspberry Pi up and running you can then install the software. The instructions to install the software can be found here The HomeBridge GitHub Readme Page. However, I found installing HomeBridge a lot easier by running a command that does the whole installation for you. Once your Raspberry Pi is up and running and up to date run “curl -sSL goo.gl/Ksdhph | bash” This will do all the work and install HomeBridge for you.
Once HomeBridge is installed you can then install the Nest plugin and follow these directions at the plugin webpage to get the Nest Developer account setup and the HomeBridge plugin configured. Homebridge-Nest Plugin page.
Are there any downsides to using HomeBridge with Nest?
Because the HomeBridge uses the official Nest API there is really no risk or downside to using HomeBridge. Nest will not be upset with you or come after you in anyway this API is officially supported. Sometimes when opening the Home App there is a slight delay in connecting to the HomeBridge devices they will say updating but this is only a few seconds and it doesn’t happen every time you open the Home app.