CircadiaOSCan Garmin or Fitbit control my thermostat? Not on their own. Neither Garmin nor Fitbit has a thermostat integration. CircadiaOS reads your Garmin or Fitbit sleep data and sends a four-phase overnight schedule to your ecobee, Honeywell Home, Google Nest, or Sensi thermostat, refining it from your nights on Premium.
Your tracker measures, then nothing changes
Every morning you get a sleep score, stages breakdown, and heart rate data. Garmin shows you Body Battery. Fitbit shows you a Sleep Score and readiness metrics. Then tonight the room is the same temperature it always is. The data never reaches the thermostat. CircadiaOS closes the loop.
Three steps, about five minutes
- Connect Garmin or Fitbit. In the CircadiaOS app, choose your wearable and authorize the connection. CircadiaOS reads your nightly sleep stages, heart rate, HRV, and respiratory rate after each night is finalized.
- Connect your smart thermostat. Sign into your ecobee, Honeywell Home, Google Nest, or Sensi account and authorize once. Full list.
- Let it run. Tonight your thermostat follows a four-phase temperature curve built from your profile. On Premium, after 14 nights of calibration, CircadiaOS starts adjusting one setpoint at a time, keeping only the changes your sleep data supports.
What each tracker gives CircadiaOS
Garmin
Garmin watches provide sleep stages (light, deep, REM, awake), heart rate, HRV (on models with the HRV Status feature), respiratory rate, and SpO2 on supported models. Garmin's Body Battery score is driven by these metrics, and CircadiaOS reads the underlying data rather than the score itself.
Fitbit
Fitbit devices provide sleep stages, heart rate, HRV (on Sense, Sense 2, Charge 5, and Charge 6), respiratory rate, and SpO2 on supported models. Fitbit Premium is not required — CircadiaOS reads the base sleep data that every Fitbit tracker records.
Not on Garmin or Fitbit?
Oura Ring, Apple Watch, and Whoop work too. Oura guide · Apple Watch guide · Whoop guide · Full compatibility list.
Questions
Can Garmin control my thermostat?
Not by itself. Garmin tracks sleep but has no thermostat integration. CircadiaOS reads your Garmin sleep data and sets your smart thermostat's overnight schedule, refining it from your nights on Premium.
Can Fitbit control my thermostat?
Not by itself. Fitbit has no thermostat integration. CircadiaOS reads your Fitbit sleep data and sends a four-phase overnight schedule to your thermostat.
Do I need Fitbit Premium?
No. CircadiaOS reads the base sleep data that every Fitbit tracker records — sleep stages, heart rate, and respiratory rate. Fitbit Premium adds additional insights in the Fitbit app, but CircadiaOS does not require it.
Which Garmin watches work?
Any Garmin watch that records sleep stages works with CircadiaOS. Models with the HRV Status feature (Venu 3, Forerunner 265/965, fenix 7 Pro and later) provide additional signal for schedule refinement.
Related guides
- Oura Ring + thermostat — the same loop, with Oura's sleep data.
- Apple Watch + thermostat — use Apple Watch sleep data to drive your thermostat.
- Whoop + thermostat — use Whoop recovery data to drive your thermostat.
- Best temperature for sleep — why the research points to a curve, not a number.
- Setup guide — everything you need and how to get started in five minutes.