Shaping the Scope
The architecture discussions continued, refining the scope and making practical decisions about implementation.
Sync Scope: Per-App Isolation
Each app gets its own isolated sync scope. The user provides or creates it:
- GDrive/OneDrive: One shared folder per app. Content is app-agnostic—just
.sync-state/, collection folders, and document files. - Custom API: Namespace-scoped. RBAC controls access. The namespace is part of the URL path.
This means:
- Home Inventory has its own GDrive folder
- Expense Ledger has its own GDrive folder
- No cross-contamination between apps
Tombstone Handling: Soft Deletes with Cleanup
Deletes are soft—meta.deleted = true. But tombstones need eventual cleanup:
- When all devices have synced (their
lastSync >= doc.modified), the tombstone can be deleted permanently - Each device writes its last sync timestamp to
.sync-state/{deviceId}.json - The cleanup logic checks if all devices have seen the tombstone
Conflict Resolution: Automated with Escape Hatch
The default is LWW (Last-Write-Wins) per field—automatic and conflict-free. But the app can opt into manual resolution:
- The SDK provides both versions
- The app decides how to merge
This hybrid approach works for most use cases while keeping the door open for complex scenarios.
The per-app sync scope is a masterstroke of isolation. By giving each application its own sync territory, Synccraft avoids the nightmare of cross-app dependencies. The tombstone cleanup mechanism is particularly elegant—it ensures data consistency without requiring explicit coordination between devices.