CircadiaOSWhat works with CircadiaOS
An iPhone, a Wi-Fi smart thermostat, and optionally a wearable. Here is the current list.
Smart thermostats
CircadiaOS connects through a thermostat integration partner. Sign in to your thermostat account once inside the app.
| Brand | Status | Notes |
|---|---|---|
| ecobee | Supported | All Wi-Fi ecobee models. |
| Honeywell Home | Supported | T-series and Lyric Wi-Fi models. |
| Google Nest | Supported | Nest Learning Thermostat and Nest Thermostat. Requires a Google account with the thermostat linked in Google Home. |
| Sensi | Supported | Wi-Fi Sensi models. |
| 15+ more | Via HomeKit & SmartThings | The connection screen in the app shows the live list. |
Not supported: shared building HVAC without an in-unit thermostat, window AC units, and radiators without a Wi-Fi thermostat.
Wearables
Sleep data reaches CircadiaOS after each night is finalized. A wearable is optional on all plans and unlocks personalization on Premium.
| Wearable | Signals used | Premium block length |
|---|---|---|
| Oura Ring | Sleep stages, HRV, resting HR, respiratory rate, skin temperature, readiness and sleep scores | ~7 nights per change |
| Fitbit | Sleep stages, HRV, resting HR, SpO2, sleep score | ~7 nights per change |
| Apple Watch | Sleep stages, heart rate, HRV, respiratory rate, wrist temperature | ~10 nights per change |
| Whoop | Sleep stages, HRV, resting HR, respiratory rate, skin temperature, recovery and sleep scores | ~14 nights per change |
| Garmin | Sleep stages, heart rate, HRV, respiratory rate, sleep score | ~14 nights per change |
Block lengths reflect how much noise each device's signals carry and may be tuned over time.
Phone and region
- Phone
- iPhone running iOS 18 or later. No Android app yet.
- Region
- United States App Store.
- Internet
- Your thermostat and wearable must be online. If the connection drops, the thermostat keeps its last setting.
Compatibility questions
Does CircadiaOS work in an apartment?
If your apartment has its own Wi-Fi smart thermostat that you control, yes. If heating and cooling are run by the building, CircadiaOS cannot control the temperature — though the Free plan still gives you a schedule you can follow by hand.
My thermostat is not on the list. What can I do?
Check the connection screen in the app, which shows the live list from our integration partner. If yours is still missing, email support@circadiaos.com with the brand and model.
Does it work with Samsung Galaxy Watch or Google Pixel Watch?
Not directly today. CircadiaOS reads Oura, Whoop, Apple Watch, Garmin, and Fitbit. Because the app is iPhone-only, Apple Watch is the most common choice.
Can two people in the same bed use it?
One thermostat controls one room, so one CircadiaOS account drives the schedule. A partner can use the Free plan with their own wearable to see their nights.