Set up CircadiaOS in five minutes

What you need

Required

• iPhone. CircadiaOS is an iOS app. It runs in the background and sends your thermostat schedule each evening.
• Wi-Fi smart thermostat. Any thermostat that connects to the internet and has an API. CircadiaOS works with Nest, ecobee, Honeywell Home, Sensi, and 20+ more through HomeKit and SmartThings. Full compatibility list.

Optional but recommended

• Sleep-tracking wearable. Oura Ring, Apple Watch, Whoop, Garmin, or Fitbit. On Premium, CircadiaOS reads your wearable's sleep data to run one-variable-at-a-time experiments on the schedule. Without a wearable, you still get the four-phase schedule — it just does not adapt over time.

Setup, step by step

Step 1: Download the app

CircadiaOS is free to download. The Free plan gives you a starting temperature schedule built from your age and sleep window, plus nightly sleep data and trends if you connect a wearable. No credit card required.

Download from the App Store.

Step 2: Connect your thermostat

In the app, tap "Connect thermostat" and sign into your thermostat account (Google for Nest, ecobee, Honeywell Home, etc). You authorize CircadiaOS once, and the connection stays active. CircadiaOS only touches the thermostat during your sleep window — your daytime schedule, home/away routines, and any other automations continue as normal.

Step 3: Connect your wearable (optional)

Tap "Connect wearable" and authorize your sleep tracker. CircadiaOS reads your nightly sleep stages, HRV, heart rate, and temperature data after each night is finalized. It uses this data to grade each block of nights and decide whether a schedule change helped or not. How the Oura connection works.

Step 4: Set your sleep window

Tell CircadiaOS when you usually go to bed and when you wake up. It uses this to time the four phases of the schedule. If your bedtime shifts night to night, the schedule shifts with it.

Step 5: That is it

Tonight, CircadiaOS sends a four-phase temperature schedule to your thermostat before you go to bed. The room cools as you fall asleep, reaches its lowest point during the deep-sleep window, warms slightly in late night, and comes up a few more degrees before your alarm.

What happens on your first night

Your thermostat receives four setpoints timed to your sleep window. The room starts around 70°F as you get into bed, drops for deep sleep, holds slightly warmer in late night, and warms before your alarm. You do not need to touch the thermostat or the app.

In the morning, if you have a wearable connected, CircadiaOS reads your sleep data and logs it. On Premium, after the first 14 nights of running the starting schedule, CircadiaOS begins testing small changes — one setpoint at a time, held for one to two weeks, kept only if the data supports it. How the method works.

What CircadiaOS does not do

• It does not require new hardware. No bed cooler, no pad, no water tank.
• It does not change your thermostat during the day. Only the sleep window is managed.
• It does not make large temperature swings. Adjustments are one degree at a time.
• It does not share your data with advertisers. Privacy policy.

Questions

Related guides

• Sleep temperature quiz — see what your overnight curve looks like before you start.
• Cost comparison — CircadiaOS vs Eight Sleep vs Sleepme.
• How it works — the four-phase schedule and one-variable-at-a-time experiments.
• Best temperature for sleep — the research and the overnight curve.
• Why do I wake up at 3am? — the temperature connection most people miss.
• For hot sleepers — settings and strategies when you run hot.
• Couples + thermostat — when one partner runs hot and the other runs cold.

Ready to start?