Backup & Sync Overview
Local-first
Comma is designed to work completely offline. Your data lives in a SQLite database on your device — no account required, no server to sign up for, no monthly fee to keep your history accessible.
This is an intentional design choice, not a limitation. Gig workers’ earnings records are sensitive financial data. Comma’s position is that you should own your data, not us.
What this means in practice:
- Open Comma on an airplane with no signal — everything works.
- Comma has no servers that can go down and take your data with them.
- No subscription can expire and lock you out of your history.
- Comma cannot see your earnings, location, or expenses — even if we wanted to.
The tradeoff
Local-first has one real tradeoff: if you lose your phone, you lose your data — unless you have a backup.
Comma offers two ways to protect against data loss:
-
Manual backup — a whole-database snapshot encrypted and saved to your Google Drive. You press a button, it uploads. Available to everyone, free.
-
Cloud sync (coming soon) — automatic, continuous, multi-device. Changes on Phone A appear on Phone B within one session boundary. Designed for users with two devices or who upgrade phones frequently.
Backup vs. sync — what’s the difference?
These terms get confused. In Comma, they mean specific things:
| Backup | Cloud Sync | |
|---|---|---|
| How it works | Point-in-time snapshot of the whole database | Record-level change-logs merged continuously |
| Direction | One-directional (save or restore) | Multi-directional (both devices stay current) |
| Trigger | Manual (you press “Backup Now”) | Automatic (on app open and app close) |
| Restore | Wipes local data and replaces it | Non-destructive merge — neither device is wiped |
| Multiple devices | Clunky — last restore wins | Native — designed for this |
| Status | Available now | In development |
If you have one phone and just want protection against losing it, backup is everything you need.
If you use two phones, recently got a new phone, or want seamless history across devices, cloud sync is what you’re waiting for.
Where your data lives
Local database
/data/data/com.comma.app/databases/comma.db (Android) or the equivalent app sandbox on iOS.
This is a standard SQLite file. All your shifts, expenses, vehicles, and goals are in this file. Comma uses Drizzle ORM to read and write it.
Google Drive (if enabled)
Data backed up to Google Drive goes into the appDataFolder — a special hidden folder that is:
- Only accessible by Comma (not visible in your Drive file browser)
- Tied to your Google account
- Deleted if you remove Comma’s Drive access
Your backup files are named comma-backup-{timestamp}.comdb for full backups, and comma-cl-{deviceId}-{timestamp}.cmlog for sync change-logs. Both are encrypted before upload.
Encryption
All cloud data (backups and sync change-logs) is encrypted on your device before upload. Google never sees your plaintext data.
Encryption uses AES-256-CBC with a key derived from your backup passphrase via PBKDF2. The passphrase is stored in your device’s secure enclave (iOS Keychain or Android Keystore), never in plaintext.
Warning: if you forget your passphrase, your cloud data is permanently unrecoverable. There is no password reset — the passphrase is the sole input to the encryption key, by design. Comma cannot recover it for you.
See Encryption for full technical details.
Privacy guarantee
Comma’s cloud integration uses Google Drive’s appDataFolder, which means:
- Your backup files do not appear in your Drive file browser.
- No one else with access to your Drive (shared drives, family plans) can see them.
- The files are encrypted — even Google cannot read the contents.
- Comma’s developers cannot access your Google account or your files.
Comma does not collect analytics, telemetry, or usage data of any kind.
Next steps
- Google Drive Backup — Set up your first backup
- Cloud Sync — How multi-device sync will work
- Encryption — Technical encryption details