Privacy

It sees when, never what.

Last updated · 9 August 2026

The short version

Couple Sync reads busy/free intervals only from Google Calendar — never an event title, guest list, location, or description. Your partner sees when you're free, never what you're doing. No ads, no data sales, no analytics trackers.

What we store

1. Your Google account basics — email, display name, and profile photo, from Google sign-in (handled by Firebase Authentication).
2. Busy/free intervals — start and end times of busy periods, fetched via Google's free/busy API. The API never returns event details, so we never see them.
3. Your timezone, so overlap windows are computed at the right local times.
4. Blocks you create in the app — including an optional title. A block marked only me shapes the overlap result, but its title never leaves the server to your partner.
5. A push-notification token (Firebase Cloud Messaging) so your partner's updates reach your phone.

How it's used

Intervals from both partners are compared on our server to compute mutual free windows, which are sent to the two of you and nobody else. There are no other users, no social graph, no public profile.

Where it lives

Data is stored in a single self-hosted PostgreSQL database operated by the developer. Identity and push delivery are handled by Google Firebase. Traffic is encrypted in transit (TLS via Cloudflare). Data is not shared with, sold to, or processed by any other third party.

Your controls

Calendar access is read-only and can be revoked at any time in your Google account permissions — Couple Sync simply stops seeing new busy periods. To delete your account and all stored data, open an issue on GitHub and it will be removed.