SelfSenseSelfSense HRV

Privacy Policy

Last updated: 18 May 2026

The short version

We respect your data and try to collect as little of it as possible.

  • App data — HRV, movement, breathing sessions — stays on your device. We don't see it, we don't store it on our servers, and we don't have any way to access it unless you explicitly choose to sync.
  • If you do sync to the optional SelfSense Server (either the hosted instance at server.selfsense.me or a self-hosted one), the data goes into a private namespace gated by a token only you hold. We have infrastructure access for keeping the service running, but we don't read, share, or analyse your data.
  • We track basic, anonymous app and website usage to improve the experience — page views, button clicks, rough device type. No names, no health data, no individual identification.
  • We don't sell, trade, or share your data with third parties for advertising, profiling, or any other purpose.
  • We don't use third-party advertising or tracking pixels.

What we actually collect

1. App and website analytics

We use Vercel Analytics to count page views and basic interactions on this website. This is privacy-friendly analytics by design: no cookies, no cross-site tracking, no personal identifiers. It tells us things like "the breathing-for-HRV page was viewed 240 times this week" — not who viewed it.

Inside the SelfSense iOS app we may collect anonymous, aggregated usage events of the same kind — which features are being used, where users get stuck — to improve the product. We never associate these events with your name, email, or any health data.

2. HRV, movement, and session data

All raw sensor data — heart rate, RR intervals, accelerometer streams, computed DFA alpha values, breathing session logs — is stored locally on your iPhone or Apple Watch in the SelfSense app's private storage. It does not leave your device unless you choose to enable server sync.

When you connect a Polar H10, Movesense, or Apple Watch sensor to the app, the data flows directly from the sensor to your phone over Bluetooth. We are not in the loop.

3. Optional server sync

The SelfSense Event Server is an opt-in companion service. If you choose to use the hosted instance at server.selfsense.me, your data is sent over an encrypted WebSocket connection into a private namespace identified by a token only you possess. The data is stored on the server only for as long as you have a session running or until you delete it. We do not read, analyse, or share data in any namespace.

If you self-host the server, none of this data ever touches our infrastructure at all.

4. Newsletter and contact

If you choose to subscribe to our newsletter, we collect your email address only for the purpose of sending you the newsletter. You can unsubscribe at any time via the link in every email. We don't share email addresses with anyone.

If you contact us via the Nodus Labs support portal we use that information only to respond to your enquiry.

What we don't do

  • We don't sell your data. Not to anyone, for any price.
  • We don't trade or share your data with advertisers, data brokers, insurers, or research partners.
  • We don't use advertising pixels, third-party trackers, or cross-site identifiers on this website or in the app.
  • We don't build behavioural profiles of users for any purpose other than improving the app's UX in aggregate form.

Your rights

You can, at any time:

  • Delete the app — this removes all locally stored sensor and session data.
  • Delete your server namespace — this removes any data you may have synced to server.selfsense.me. Get in touch via the support portal to do this.
  • Unsubscribe from emails — via the link in any newsletter, or by writing to us.
  • Request a copy or deletion of any data we hold about you — under GDPR, UK GDPR, and similar regulations. Contact us via the support portal.

Service provider details

SelfSense is operated by Ways Ltd, trading as Nodus Labs.

Carrwood Park, Selby Road, Leeds
LS15 4LG, United Kingdom
Company number: 05039341

For any privacy-related question, contact us at the Nodus Labs support portal.

Changes to this policy

If we make material changes to how we handle your data, we will update the "Last updated" date at the top of this page and, where appropriate, notify users via the app or the newsletter.