This is a personal diabetes-tracking tool. It stores health-related information you provide or that is pulled from your connected LibreLinkUp (Abbott Libre) account, in order to show your glucose trends, charts, and records inside the app.

• Your LibreLinkUp email and password, used to sign in to Abbott's LibreLinkUp service on your behalf so glucose readings can be fetched.
• Glucose readings synced from LibreLinkUp (value, timestamp, trend, source/device metadata).
• Any medications, appointments, doctors, and services you add manually.
• Sensor records you register (start/end dates, notes) and the sensor event log.
• App settings (units, alert thresholds, alarm preferences, timezone).
• If you link Discord: your Discord user ID, used to match alert/notification requests to your account.
• API keys you generate for widget/integration use (stored as a hash, not in plain text).

Your LibreLinkUp password is encrypted before it is written to the database (not stored as plain text) and is only decrypted server-side when needed to sign in to LibreLinkUp on your behalf. Sign-in to this app itself uses a JWT session cookie. Even so, treat your account — and any API key you generate — like you would any other password: don't share it, and only use this app on devices you trust.

Your data is scoped to your account and is not visible to other users of this app. This is a self-hosted, single-operator service — nothing is sold or shared with advertisers or analytics platforms. Your LibreLinkUp credentials are sent to Abbott's LibreLinkUp service itself (that's how readings are fetched) and nowhere else.

Settings → System has a "wipe all data" action that permanently deletes your glucose readings, appointments, medications, doctors, services, settings, and saved LibreLinkUp credentials in one step (requires typing a confirmation phrase). This is separate from simply removing a saved LibreLinkUp login, which only clears the stored credentials and leaves your historical records in place. There is no automatic retention limit beyond this — data is kept until you delete it or ask for it to be removed.