Sync and offline use

Athena is offline-first: the core features do not depend on a network. The highlights you make, pages you turn and notes you write on the subway are written to this device first and synced to your other devices when you reconnect.

What works offline

Reading what is already cached, turning pages and recording progress, highlighting, writing notes, local dictionary lookups, and listening with the system speech engine.

What needs a connection

AI conversations and knowledge-base retrieval, text recognition (OCR), cloud voice synthesis, uploading newly imported files, and downloading anything not yet cached on this device.

How sync works

Changes go into a local queue and upload automatically once you are online. There is no "sync" button to press. The status is visible in the interface: items pending, syncing, or all synced.

How conflicts are handled

When two devices change the same data while offline, Athena's behaviour depends on the data type. Reading progress takes the most recent value. Notes keep both versions and let you decide — nothing you wrote is ever silently discarded. When you see a conflict notice, look at the original and the copy and delete the one you do not want.

Troubleshooting

New device, empty library: sign in with the same account and the library list syncs first; files download on demand — whichever you open is the one that downloads, so your storage is not filled at once.

Something will not open offline: it is not cached on this device yet. Open it once while online.

Stuck on "pending": check your connection. If it does not move for a long time, trigger a forced resync from the library page.

Two devices disagree on progress: let both sync once and they will align.

Limits and notes

Cloud voice API keys do not sync. That is deliberate: we neither hold nor transmit your third-party payment credentials. You re-enter the key on a new device.

Local caches use device storage. Settings → Storage shows what is used and lets you clear caches; clearing does not affect your cloud data.