Privacy Policy
This privacy policy describes how the Home Assistant × Nest integration (“the App”) handles information. The App is a private, personal project operated by Artur Souza. It is not offered to the public and has no users other than the operator’s own household.
What the App does
The App connects a Google Nest thermostat to a self-hosted Home Assistant instance running on a Raspberry Pi on the operator’s home network, using Google’s Smart Device Management (SDM) API. Its only purpose is to let the household monitor and control its own thermostat from Home Assistant.
Information accessed
Through the Google SDM API, the App accesses only data about the operator’s own Nest devices:
- Thermostat readings: ambient temperature, humidity, and heating/cooling state.
- Thermostat settings: HVAC mode, temperature setpoints, and fan settings.
- Device and structure identifiers needed to address the thermostat through the API.
The App does not access any other Google account data — no email, no contacts, no location history, no camera or doorbell footage, and no data belonging to anyone else.
How information is used
The data is used solely to display the thermostat’s state and to control it within the operator’s own Home Assistant, including simple automations (for example, showing the current temperature on a home dashboard) and estimating heating energy use from thermostat runtime.
Storage
Thermostat readings and the OAuth tokens that authorize API access are stored only on the operator’s own Home Assistant server at home. No copy of the data is kept on any other server operated by the App, and the App has no cloud backend of its own.
Sharing and disclosure
The App does not share, sell, rent, or otherwise disclose any information to any third party. There is no advertising, no analytics, and no tracking. The only external service involved is Google’s SDM API itself, which the App calls to read and control the operator’s own devices.
Data retention
Readings are retained only as configured in the operator’s Home Assistant recorder settings, and can be deleted there at any time. OAuth tokens remain valid until the operator revokes access.
Revoking access
Access can be revoked at any time, either by removing the Nest integration in Home Assistant or from the Google account’s third-party access settings at myaccount.google.com/permissions. Revoking access immediately stops the App from reading or controlling the thermostat.
Children’s privacy
The App is a household utility, is not directed at children, and knowingly collects no information from children.
Changes to this policy
If the App’s data practices change, this policy will be updated and the effective date above revised.
Contact
Questions about this policy can be sent to Artur Souza at souza.artur@gmail.com.