Account & Sync

Your account connects identity, purchases, cloud decks, resources, and learning state across devices. Sync is local-first: the app keeps data locally and exchanges changes with Cardary services when you are signed in and online.

What Sync Covers

Deck sync can include:

• deck information and preferences;
• cards and card fields;
• categories;
• tags and taggings;
• notes;
• learning schedules;
• learning logs;
• quiz logs;
• resources such as images, audio, and files;
• resource upload and download state.

Some data also remains local on the device, such as caches, temporary files, draft edits, and downloaded media.

How Sync Works

Cardary uses a WebSocket sync protocol with buckets, local update time, server time, and USN version tracking.

At a high level, sync:

1. checks the local version for each bucket;
2. pulls cloud updates after the local USN;
3. pulls cloud deletion logs;
4. pushes local updates;
5. pushes local deletions;
6. records the server sync time;
7. downloads or uploads resources when needed.

If delta sync is unavailable, the app can fall back to full sync.

Conflict Behavior

When both local and cloud records changed, newer update time wins. If the local record is newer, Cardary keeps it and marks it for upload.

Deletion is conservative. A cloud deletion should not remove a newer local record that changed after the deletion point.

Resource Sync

Media-heavy decks need more time. Images, audio, files, thumbnails, and package resources may upload or download after the main deck metadata.

Good habits:

• keep the app open until resource sync finishes after large imports;
• avoid deleting local files before sync completes;
• check media cards on the second device;
• use stable networks for large decks.

Sign-In and Purchases

Sign-in connects your account, cloud data, and CardaryPlus entitlement. Apple App Store and Google Play manage billing, while Cardary verifies purchase state so Plus features can be restored in the app.

When moving to a new device:

1. install Cardary;
2. sign in with the same account;
3. restore purchases if needed;
4. fetch or sync decks;
5. wait for resources to finish downloading.

Good Sync Habits

• Sign in before creating long-term decks on a new device.
• Let sync finish before switching devices after big edits.
• Sync soon after editing the same deck on two devices.
• Retry on a stable network if sync fails.
• Do not repeatedly edit a failing deck before resolving sync errors.
• Export critical material before destructive cleanup.
• Read Account Deletion before deleting an account with synced content.

Troubleshooting

Symptom	What to do
A deck is missing on another device	Sign in, fetch cloud decks, then sync.
Media is missing	Wait for resource download and check network status.
Recent edits do not appear	Sync the editing device first, then sync the second device.
Sync fails repeatedly	Retry on stable network and avoid further edits until it succeeds.
Purchase is not active	Use the restore flow and confirm the store account.