SwiftData sync without iCloud

SwiftData can sync through CloudKit with a single setting, and for many apps that is the right choice: it costs nothing and needs no server. It stops fitting when you need one of the things it cannot do.

When CloudKit stops fittingCopy Anchor Link

• The person must be signed in to iCloud, with room left in their iCloud storage. Without it, nothing syncs and your app is not told much.
• Your model has to fit CloudKit: every property optional or with a default, no unique attributes, and every relationship optional.
• Only Apple devices. There is no CloudKit for Android.
• You cannot see your people's data. It is in each person's private iCloud database, so you cannot export it, answer an access request from your side, or delete an account's data on the server.
• Sync happens when the system decides, and you cannot tell when it is done.

Syncing SwiftData with SyncPilledCopy Anchor Link

Keep a plain local SwiftData store (no cloudKitDatabase), and let SyncPilled copy it between the person's devices, signed in with your app's own provider.

1. Give each synced model a stable id and an updatedAt date.
2. Write a data source: a snapshot of every synced record as JSON, and an apply that writes in what arrives, checking each record is unchanged in the same step.
3. Call engine.sync() at launch, on returning to the foreground, and after saving.

Your model needs nothing CloudKit asks for: unique attributes and required properties are fine, because SyncPilled sees JSON, not your schema.

What you take onCopy Anchor Link

You run, or rent, a server: the hosted version, or your own Cloudflare account. Sign-in is yours: Firebase, Supabase, Auth0, Clerk or Sign in with Apple. And conflicts are settled per record, by the latest edit, rather than by CloudKit's own rules.