Guide
Connect your body data
Meridian learns from your sleep, resting heart rate, and daily activity. There are two ways to bring them in: Oura and WHOOP connect directly from inside the app, and everything else reaches Meridian through the Meridian app for iPhone, which reads Apple Health natively. You install it from meridianself.com/ios. There is no shortcut to add and no code to paste; that was the old beta setup, and it has been retired.
Oura and WHOOP connect directly
If you wear an Oura ring or a WHOOP band, the connection is two taps: from the first-run wizard, or any time later from Profile → Data sources → Connect. Meridian sends you to the provider's own sign-in page to approve the connection, then brings you straight back. Your password never passes through us.
After that, syncing is automatic: new days arrive on their own. If you want your latest night right now, the same row has a Sync now button.
Disconnecting is just as plain. The same row has a Disconnect button; tapping it stops new data immediately and deletes the stored connection at our end, while the days already synced stay in your history.
Wearing an Apple Watch, or a Garmin, Coros, or Amazfit watch? Those reach Meridian through Apple Health instead, and the rest of this guide walks you through it.
What you need
- An iPhone.
- A wearable that writes to Apple Health: Garmin (via the Garmin Connect app), Coros (Coros app → Profile → Settings → 3rd Party Apps → Apple Health), Amazfit (Zepp app → Profile → Add accounts → Apple Health), or an Apple Watch (nothing to set up).
- The Meridian app for iPhone, installed from meridianself.com/ios.
Set up the app
Check your wearable feeds Apple Health. An Apple Watch does this by itself. Garmin, Coros, and Amazfit each need the one-time link to Apple Health described under What you need; once it is on, every new night and day flows into Apple Health on its own.
Install the Meridian app for iPhone. Open meridianself.com/ios on your iPhone and tap Install on iPhone. TestFlight is Apple's app for beta software; if you do not have it yet, the link walks you through installing it first, then the Meridian app.
Sign in and allow Health access. Signing in works exactly like the web app: an 8-digit code sent to your email, or Sign in with Apple. Then a few first-run questions set things up, and when you name your device the app offers the Health connection right there:
- Tap Allow Health access. iOS puts up its own Health sheet listing every category Meridian asks for: use Turn On All, or tick every row by hand. Meridian reads sleep, resting heart rate, and activity, and partial access is the single most common cause of a mirror with holes in it.
- Skipped that screen? No harm done: you can connect any time from Profile → Data sources → the Apple Health row → Connect.
Either way it is a single approval: once Health access is on, the app never asks again.
Turn on your daily reminder. Body data arrives on its own; the check-in is the part that needs you. In the app, go to Profile → Daily reminder and switch on Check-in reminder. iOS asks once whether Meridian may send notifications: allow it, then pick the hour under Remind me at.
It is one notification, at the hour you chose, and only on a day you have not checked in yet. Nothing else in Meridian ever notifies you. If you declined by reflex, iPhone Settings → Notifications → Meridian → Allow Notifications, then switch the toggle again.
Nothing else. There is no schedule to set and nothing to run: the app syncs when you open it and quietly in the background between opens. Away from it for a few days? The missed days catch up the next time you open it.
That's it. Open Meridian and your recent days appear in Today and Analytics, labelled with their source.
How you know it's working
Your first body rows appear the morning after you connect: last night's sleep, yesterday's activity and resting heart rate, each labelled with its source. From then on the app keeps itself current: it syncs on open and quietly in the background, and a few missed days catch up on the next open. If rows stop appearing, the troubleshooting list below covers the usual causes.
Privacy, plainly
The Meridian app reads only sleep, resting heart rate, and activity from Apple Health, and it is read-only: it never writes to or changes anything in Health. What it reads goes only to your own Meridian account over an encrypted connection. Nothing is shared with third parties, ever. Full detail in our Privacy Policy.
Troubleshooting
- No data appearing? Check Apple Health itself first: open Apple Health → Browse and look at Sleep and Steps for those days. Meridian can only read what Apple Health holds; if the days are empty there, your wearable is not writing to Apple Health (see below).
- Apple Health has the data, but Meridian does not? Check Health access: iPhone Settings → Privacy & Security → Health → Meridian, and turn every category on. Partial access leaves gaps that look like missing days.
- No daily reminder arriving? Check two switches: iPhone Settings → Notifications → Meridian → Allow Notifications, and then Check-in reminder in the app under Profile → Daily reminder. A reminder is also skipped by design on any day you have already checked in.
- Wearable not writing to Apple Health? Garmin: install Garmin Connect and let it connect to Apple Health. Coros: Coros app → Settings → 3rd Party Apps → Apple Health. Amazfit: Zepp app → Profile → Add accounts → Apple Health. An Apple Watch needs nothing; it writes on its own.
- Been away for a few days? That is fine: the app catches up the missed days by itself the next time you open it.
- Lost the TestFlight link? It is on meridianself.com/ios, and in your welcome email.
- Still stuck? Reply to your beta email with what you see; a person reads it and answers.