Metrics Nest

Two products

The app, and the API

The app keeps your health on your own phone. The Nest API, coming soon, lets you hand it to an AI, a dashboard or a coach — read-only, and yours to switch off.

In any AI conversation

Ask a question. It reads your numbers, not a guess.

Connect it the way you connect any other tool. Every call it makes is written in your access log. Pick a question.

How did my sleep change after I started lifting in the mornings?

  1. list_metrics
  2. list_workouts { activity: "strength", start: "2026-06-01" }
  3. query_metrics { metrics: ["sleep_asleep_secs", "sleep_deep_secs"], granularity: "week" }

Your first 7 a.m. session was on 22 June. In the six weeks since, you have fallen asleep 22 minutes earlier on average and deep sleep has risen from 48 to 61 minutes a night. Nights after a morning session average 7h12; other nights 6h41. The one week that broke the pattern was the trip in the second week of August.

Hours asleep, weekly average

Example answer, from example numbers. Nothing here has read anybody’s data.

You choose, category by category

What leaves your phone is a list of switches.

Nine categories, nine switches. The right-hand side is exactly what anyone you let in could read.

For a coach, and the coach never pays

Send a link. Approve them. Stop them whenever you like.

  1. 01

    You send a link

    Tick what they may see and send the link. It carries nothing about you, works once, and expires in a week.

  2. 02

    They ask

    They sign in and ask to be your coach. Nothing is granted yet.

  3. 03

    You approve

    Your phone shows who is asking and for what, with a four-word code you can check with them. Approve, and they read what you ticked.

  4. 04

    You can revoke in one tap

    Quietly. Nobody should need a conversation to stop being looked at.

What it costs

The app, and one add-on on top.

The Nest API is an add-on to Unlimited, lifetime included — and a subscription, never lifetime, because it runs on a server. Choose a combination to see what a year costs.

The app: Unlimited
The Nest API add-on Coming soon
The app
£39.99 a year
The add-on
£24.99 a year
First year
£64.98
Every year after
£64.98

Two subscriptions, each with its own free month. Cancel either in Settings, and the other carries on.

UK App Store prices, billed by Apple; the add-on’s are planned and may change before it ships. The terms say what lifetime covers.

Questions

The ones worth asking before a health API.

Can anything write to my phone through this?

No. Every door is read-only — a key, a connection from Claude, a coach. The only thing that ever writes is the app on your phone.

Where does the data live?

On a server in the EU, against a random ID with no name, no email and no date of birth. You choose how long it is kept, you can export it, and one tap deletes it.

Do coaches pay?

Never. You pay, and invite them with a link. They read only what you ticked, and you can stop them in one tap without a conversation.

Does lifetime include it?

No. The app runs on your phone and costs nothing more to serve; the add-on runs on a server, so it is a subscription. A lifetime holder adds it on top for £24.99 a year.

Which wearables does it cover?

Whatever writes into Apple Health: Apple Watch, Oura, Garmin, WHOOP, Withings, Polar and most others. Their raw readings pass through; their own proprietary scores do not.

When?

The app is the product today. The Nest API ships as an in-app add-on when it is ready. Nothing on this page collects an email, because nothing on this site collects anything.

The app today. The API when it is ready.

Everything the API will serve is already on your phone. Start there.

Download on the App StoreHow the app works