From signup to your first debrief.

One path, in order. Karoo 2 or 3, a Polar H10, a USB cable, and your own Claude. Sign up below, then follow the steps down the page.

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The extension reads the Polar H10 only, today. Other straps still work with the Karoo, but veloVigil won't record their HR yet.

Your invite code comes by email from robert.chuvala@gmail.com. Then continue with step 2 below.

Beta is full

All 100 spots have been claimed. Follow the repo for updates on the public release.

The path

Seven steps. Screens are shown where we have them; three Karoo photos are still to come, and for those the words are exact.

1

Sign up, get your invite code

The form above. Codes are sent by hand, by email, from robert.chuvala@gmail.com. One code registers one Karoo; if you reinstall, reply to the email and ask for another.

2

Sideload the extension

  1. Download velovigil-v0.3.2.apk
  2. USB to the Karoo → on the Karoo choose File Transfer → copy the file into the Download folder
  3. On the Karoo: Settings → System → File Manager → Download → tap the file → Install. "Retry" on a Karoo 3 is normal; tap it again.

Longer version with every screen.

The v0.3.2 release page on GitHub with the APK to download
3

Allow the permission

Open veloVigil → Settings. It asks once. Karoo 2: Location. Karoo 3: Nearby devices + Location. Tap Allow.

This is the step that was missing before 0.2.4. Without it the H10 scan never runs and every ride records a heart rate of 0. If you see no prompt: Karoo Settings → Apps → veloVigil → Permissions.

[ photo of the Karoo permission prompt: coming; the words above are exact ]
4

Register with your code

Same Settings screen: paste the code into Invite Code, tap Register with Invite Code. Your Rider ID (rider_…) appears right there. Write it down; it is your dashboard address.

[ photo of the Settings screen with the Rider ID: coming ]
5

Pair the H10 through veloVigil

  1. If the H10 is already paired to the Karoo directly, remove it: Settings → Sensors → the H10 → Forget
  2. Put the strap on (wet the electrodes)
  3. Settings → Sensors → Scan → pair veloVigil HR (puzzle-piece icon)
  4. Not in the list? Back out and scan again. The first scan after installing or rebooting often doesn’t show extension sensors; the second one does (seen on a Karoo 2, 2026-08-26).

Two pairings at once give you a fight over one strap: double readings, or 30–40 bpm nonsense. One pairing, through veloVigil.

[ photo of Sensors → Scan → veloVigil HR: coming ]
6

Accept the pairing request

  1. Within about 30 seconds of pairing, swipe down from the very top of the Karoo screen
  2. You'll see Pairing request — Tap to pair with Polar H10. Tap PAIR & CONNECT
  3. Once. The Karoo remembers it.

This is the step nobody could see. The H10 asks the Karoo for an encrypted link; the Karoo's own sensor list never needs it, but veloVigil goes through Android, and Android puts the question in a notification shade a Karoo never shows you. Unanswered, it times out, the link drops, and every ride records a heart rate of 0 — the 0.2.x bug. If you missed it, the request comes back every ~40 seconds until you accept it. veloVigil Settings says H10 PAIRING REQUEST WAITING while it's up.

The Karoo notification shade showing 'Pairing request — Tap to pair with Polar H10' with a PAIR & CONNECT button, over a ride page reading HR 72
7

Ride

Start a ride like normal. Ten minutes is enough for a first check. veloVigil uploads every 5–10 seconds while it has signal and buffers when it doesn't.

Your dashboard: velovigil-fleet.robert-chuvala.workers.dev/dashboard/<your Rider ID>. The ride should appear with a heart rate that isn't 0. If it is 0, go back to steps 3, 5 and 6.

A rider dashboard listing rides with distance, time, average HR and speed
8

Coach yourself with your own Claude

  1. On the dashboard, open the ride and click Copy markdown
  2. Open claude.ai, start a new conversation, paste
  3. Ask: "Coach me on this ride." Then: "What does my HRV say about recovery?", "Compare this to my last ride."

Paste, don't link. Claude's web tool can't reach the API from claude.ai, so a link fails and the paste works. Nothing goes to us.

Prompts that work well · What's in the export

A ride card on the dashboard with the

Stuck? Reply to your invite email with a photo of the screen. That's the support channel; it's read.