Cairn 2.0 · self-hosted · open source

Become.

A coach that has already read your whole day, and has one honest thing to say.

Get it on GitHub Try the demo in your browser

The demo runs a real Cairn on fictional data in a GitHub Codespace. Nothing touches your machine.

Cairn reads your lifting, running, food, sleep, labs and life as one picture. It opens to a calm read of today: rest, easy or train, with the reasons shown. A team of specialists works quietly behind it, makes the small calls, and gives you a one-tap Undo for each one.

It runs on your own hardware, keeps everything in a SQLite file you own, and never scores you or nags you.

Today

It reads your day.

Today opens on an answer, not a dashboard. Rest, easy or train, in one sentence, with the evidence a tap away: last night's sleep, your HRV against your own band, the load you carried this week, the knee you mentioned on Tuesday.

A suggestion, never a gate. A missing night says nothing, never "bad".

The team

The team decides. You can Undo.

Strength, endurance, nutrition, physio and an informational health seat each watch their part of you. When the evidence is clear, a bounded change lands on its own, with its why in plain words and one tap to put it back. Anything clinical, irreversible or goal-changing still asks first.

Labs

Your blood's been talking.

A flagged marker doesn't sit in a PDF. It travels into your meals, your training and your watch, each with its why and a citation. Before a visit, the doctor packet builds itself, in clinical order.

Informational, never medical advice.

Fuel

Measured, not punished.

Type a meal the way you'd say it, or snap the plate, and it comes back as a card you can correct. Expenditure comes from your real weight trend. A thin logging week lowers confidence; it never blames you.

Horizon

A race build sized to you.

Name a half marathon and Horizon draws the road to it from the weeks you actually ran. The best week you've already run safely sets the floor; the peak aims just past it. Strength keeps progressing all the way to race week.

You

Six stones. One picture.

Strength, endurance, fuel, recovery, body and heart, each with one word for where it stands right now. Tap a stone to see what it leans on: a ferritin still catching up quietly holds the running back.

Words and your own baseline, never a 0–100.

The rules don't change.

No scores. No grades, no 0–100, no metric walls.
No streaks. Nothing to keep alive, nothing to lose.
Nothing pushed. Insights wait in the app until you want them.
A suggestion, never a gate. Every read is advice. You drive.
Clinical asks first. Anything medical waits for your yes.
Yours. Your hardware, one SQLite file, MIT licensed.

Run it tonight.

One container, amd64 or arm64. A Raspberry Pi is plenty.

docker run -d --name cairn -p 127.0.0.1:8787:8787 \
  -v cairn-data:/data -v cairn-home:/home/app \
  -v cairn-tools:/home/app/.cairn-tools \
  --restart unless-stopped ghcr.io/zilet/cairn:latest

Then open http://localhost:8787. Garmin, Apple Health, lab PDFs and the coaching agents (Claude Code, Codex and others) are set up from inside the app. Quickstart →