Privacy
Last updated September 30, 2026
one sentence a day is a private journal. This page explains, in plain terms, what we store, how it's protected, and who it is shared with. It's an early beta — this policy will grow as the product does.
What we store
- Your account — we use Google sign-in and keep your account identifier and email.
- Your entries — the one sentence you write each day and its date.
- AI-generated content derived from your entries — the emoji on each sentence and the weekly and monthly reflections.
Encryption at rest
The text of your entries and reflections is encrypted at rest in our database. On its own, that data is unreadable — decrypting it requires keys that are managed separately and never stored alongside your entries.
AI processing
To generate the emoji and the weekly and monthly reflections, the text of your entries is sent to OpenAI, our AI provider, over an encrypted connection. Per OpenAI's API terms, data sent through their API is not used to train their models. Your entry text is decrypted only in memory for this purpose and to display it back to you.
Access and isolation
Sign-in is handled by Google OAuth. Each account's entries are isolated at the database level — only you, signed in, can read or change your own entries. We do not sell your data, and we do not share it with anyone beyond the providers needed to run the service: Supabase (database and authentication), Vercel (hosting), and OpenAI (the AI features described above).
Your control
Your journal is yours. You can edit or overwrite any day's entry at any time. To delete your entries or your account entirely, reach out and we'll remove your data — deleting your account removes all entries and reflections tied to it.
Contact
Questions about your data, or want it deleted? Contact us at contact@onesentenceaday.com.