Watt Stalker

Privacy Policy

Effective September 29, 2026

Watt Stalker is a personal, self-hosted home-energy tool operated by Brilliant Sys for a single household. This policy explains what data it uses, why, and where that data goes.

Who uses Watt Stalker

Watt Stalker is not a public service. It has no sign-ups and no users outside the household that runs it. The only Google account ever connected to it is that household’s own.

Data from Google (Nest thermostats)

With the account owner’s permission, Watt Stalker uses Google’s Smart Device Management API to read information about the household’s Nest thermostats:

It also uses Google Cloud Pub/Sub to receive notifications when those values change.

Watt Stalker does not request or access email, contacts, calendars, location history, cameras, microphones, or any other Google data.

How the data is used

Only to show the household its own heating and cooling activity and to estimate how much electricity and money that activity uses. Watt Stalker does not control or change thermostat settings.

Where the data is stored

On a private server inside the household, reachable only from the home network. It is not stored in a third-party cloud database. Watt Stalker keeps readings for as long as they’re useful for comparing seasons and years.

Sharing

Data is never sold, shared with third parties, used for advertising, or used to train AI or machine-learning models.

Watt Stalker’s use and transfer of information received from Google APIs adheres to the Google API Services User Data Policy, including the Limited Use requirements.

Other data

Watt Stalker also stores power readings from the household’s smart plugs and the household’s own utility meter data. These stay on the same private server.

Removing access and deleting data

This website

This site uses no cookies, analytics, trackers, or third-party scripts.

Changes and contact

If this policy changes, the effective date above will be updated. Questions: bryan@brilliantsys.net.