Privacy Policy

Last updated: 4 July 2026

glucodroid.cloud is an infrastructure relay service for continuous glucose monitor (CGM) data. Your glucose readings are special category health data under UK GDPR / EU GDPR (Article 9). We process this data only on the basis of your explicit consent, which you provide when you create an account.

1. Who we are

glucodroid.cloud is operated as a personal infrastructure project, maintained by robster7674 (the same maintainer as the public GitHub repository). For data enquiries, contact us at privacy@glucodroid.cloud. We are the data controller for the personal data described in this policy. No Data Protection Officer has been designated; please direct all data requests to privacy@glucodroid.cloud.

2. What data we collect

Account data: your chosen subdomain (username) and, if you provide it, your email address.
Glucose data: continuous glucose readings uploaded from your CGM app via HTTPS using the standard Nightscout API. This includes: timestamp, glucose value (mg/dL), trend direction, and the device identifier your app reports.
Technical logs: standard web server access logs (IP address, request path, timestamp). These are retained for up to 30 days for security and debugging purposes.

We do not collect insulin doses, carbohydrate entries, or other treatment data.

3. Legal basis for processing

Glucose data (Art. 9 special category): your explicit consent, given at account registration. You may withdraw consent at any time by closing your account.
Account and email data: performance of the service contract (Art. 6(1)(b)) and, where you have provided your email, legitimate interest in communicating service-related information.
Access logs: legitimate interest in maintaining security and diagnosing technical issues (Art. 6(1)(f)).

4. How we use your data

To operate the relay service — storing your CGM readings and serving them to your authorised follower apps.
To send essential service communications (e.g., outage notices), if you provided an email address.
To maintain the security and integrity of the service.

We do not use your data for marketing, profiling, or automated decision-making.

5. Who we share your data with

We do not sell or share your personal data with third parties for their own purposes. Your glucose data is accessible to:

You — via your Nightscout-compatible URL and API secret.
Anyone you share your Nightscout URL and API secret with — follower apps, caregivers, or clinicians you choose to inform.
Infrastructure providers — our VPS host (Hetzner, EU data centres) processes data on our behalf under a data processing agreement. We use EU-based servers.

6. Data retention

Your glucose data and account details are retained for as long as your account is active. If you request account deletion, your data will be permanently removed within 30 days. Access logs are deleted after 30 days.

7. Your rights

Under UK GDPR / EU GDPR you have the right to:

Access — request a copy of the personal data we hold about you.
Erasure — request deletion of your data ("right to be forgotten").
Portability — receive your glucose data in a machine-readable format (JSON).
Restriction — request that we restrict processing of your data.
Objection — object to processing based on legitimate interest.
Withdraw consent — at any time, by contacting us or closing your account. Withdrawal does not affect the lawfulness of processing before withdrawal.
Lodge a complaint — with the UK Information Commissioner's Office (ico.org.uk) or your national data protection authority.

To exercise any of these rights, email privacy@glucodroid.cloud.

8. Security

All data is transmitted over TLS (HTTPS). Uploads use the Nightscout API authenticated with your API secret; reads require the same secret. Glucose data is stored in a per-user database on EU-based servers with restricted access. No security measure is perfect; we encourage you to use a strong, unique password.

9. Children

This service may be used to relay CGM data for children under parental or guardian supervision. The account must be created and managed by an adult acting as the data controller for the child's data.

10. Changes to this policy

We may update this policy from time to time. Material changes will be notified by email if you have provided one. The current version is always available at glucodroid.cloud/privacy.html.

11. Data breaches

In the event of a personal data breach affecting your data, we will notify affected users without undue delay. Where the breach is likely to result in a high risk to your rights and freedoms, we will also notify the relevant supervisory authority within 72 hours of becoming aware of it, in line with GDPR Articles 33–34.

12. Cookies and tracking

The glucodroid.cloud service does not set cookies. Specifically:

No cookies on visitors or API clients. Neither the web pages hosted under glucodroid.cloud nor the /api/v1/ endpoints issue Set-Cookie headers, and the API does not use a session cookie jar. Requests are authenticated by an API secret in the request body or header, not by a cookie.
No third-party analytics, advertising, or tracking scripts run on any page or asset we control. There is no Google Analytics, no Meta Pixel, no Hotjar, no Plausible, no Cloudflare Web Analytics, and no advertising tags. No third-party fonts or scripts are loaded from external CDNs that would set tracking cookies.
The Android client does not store cookies and does not embed a WebView. The official GlucoDroid app communicates with the API over HTTPS using OkHttp without a cookie jar, and it does not load any web content in a WebView.

Because nothing is stored or accessed on your device, no consent banner or cookie preference UI is required for normal use of the service.

If we ever change the service to set cookies, embed a WebView, or run third-party trackers, we will update this notice and, where the law requires it, collect your prior consent before those technologies are enabled.