Backup and restore.

Why backups exist#

Kata is local-first, so we never hold a readable copy of your data and cannot hand one back. A backup is the bridge: it carries everything to a new device, or brings it back if you clear the app. Everything on this page lives in Settings, Data.

The backup file#

Back up now writes one versioned file (a kata-backup envelope, schema 1) with your settings, all your logs, Kata's memory and decisions, and your photos. The progress moves through clear stages: collect your data, gather photos, write the file, verify it, done. The verify step re-reads what it wrote, so a backup that says done is a backup that is actually good. On iPhone the file is written to the app's Documents folder, and your phone's own iCloud device backup carries that folder along with the rest of the phone; on Android it is written to the app's own storage, which your Google backup carries (Backups on Android); on the web it downloads as a file.

On iPhone the file is a plain copy, readable like an export, and the values imported from Apple Health are left out of it: they stay in Apple Health, and after a restore Kata brings the last 90 days back from there.

Automatic frequency#

Choose daily, weekly, monthly or manual only; weekly is the default. In the iPhone and Android apps an automatic backup runs when you open Kata, with a small indicator showing its progress; on the web the file is a download, so automatic file backups run in the apps.

On iPhone, iCloud carries the backup#

On iPhone, your phone's own iCloud device backup is what keeps Kata safe: it carries the backup file along with the rest of the phone. Kata 1.0 on iPhone keeps no copy of its own in iCloud and no sealed snapshot on Kata's servers, so nothing restores by itself when you sign in on a new iPhone. The backup file and Export my data are how your data moves. See Changing your device.

The sealed account snapshot on the web#

The web app keeps one restore snapshot of your account, so a cleared browser or a new computer never means a lost history. Before it leaves your browser it is encrypted there with AES-256-GCM under a random key that is generated on your device and kept in that browser. We store it as one sealed row per account: refreshed after a change at most every quarter of an hour (every two minutes in a new account's first hour) and every six hours otherwise, overwritten each time, deleted with your account, never containing your photos, and ciphertext we have no technical means to read. If your device cannot encrypt, nothing is uploaded at all. The Android app keeps the same kind of sealed snapshot, with its key kept in your Google account: see Backups on Android.

Your recovery key#

The key that opens the snapshot is yours alone: Kata never receives it, in any form. In a browser it stays in that browser only. Under Moving to a new device you can show the key (52 letters and numbers), copy it, or show it as a QR code that another device's camera scans straight off the screen, never through a server. Keep a copy somewhere safe: if this browser's data and the key are both gone, the snapshot can never be opened again, by you or by us. That is what "we cannot read it" costs.

Export my data, import, restore#

• Export my data: one complete file of everything, your chat and photos included, saved through the share sheet on your phone or downloaded on the web, any time you like. It is a plain readable copy, so keep it somewhere safe; the sealed snapshot is the one that is encrypted. It works on iPhone, Android and the web alike, so it is also how you move between them.
• Import: load an exported file (or an older backup) on any device to bring that data in. Kata shows you what is in the file first, and warns you if it looks older than what is already on the device.
• Restore from backup: in the iPhone and Android apps, pick one of the backup files on this phone and pick up exactly where you were. On the web, a fresh sign-in also offers your snapshot on its own: Welcome back, we found your Kata data. On iPhone nothing restores by itself at sign-in.

Restoring or importing replaces what is currently in Kata on this device with the backup, and the app reloads right after. Kata always shows you the summary and asks you to confirm first. Moving to a new phone? See Changing your device.