Homebridge Nest pi-hub — a private, single-household application.
When the owner signs in with their Google Account, the app requests access to the Google Smart Device Management API (scope sdm.service). It uses this only to read the status of, and send commands to, the owner's own Nest thermostat: current temperature, target temperature, and heating/cooling mode.
Thermostat data is used only to show the thermostat's state in, and accept commands from, the owner's Apple Home app. It is not used for advertising, analytics, profiling, or any other purpose.
The authorization credentials are stored on a Raspberry Pi in the owner's home. Thermostat readings are held in that device's memory while the app runs. No data is sent to the developer or to any third party.
The app does not sell, share, transfer, or disclose any Google user data to anyone.
This app's use and transfer of information received from Google APIs adheres to the Google API Services User Data Policy, including the Limited Use requirements.
The owner can revoke the app's access at any time at myaccount.google.com/permissions, and can delete all stored credentials by removing them from the Homebridge configuration on the Raspberry Pi.
Questions can be raised by opening an issue on this site's GitHub repository.