Multi Process Access

Multi-Process Access

By default both stores are single-process and are not safe to touch from more than one process at a time. If a background service (Android) or an app extension (iOS) needs the same data, opt in once at startup with configure — it's non-destructive and leaves the default store untouched.

// Regular store
await NativeDatastore().configure(
  multiProcess: true,                  // Android: MultiProcessDataStore
  appGroupId: 'group.com.you.app',     // iOS: shared App Group (UserDefaults)
);

// Secure store (same signature)
await SecureDatastore().configure(
  multiProcess: true,                       // Android: multi-process encrypted store
  appGroupId: 'TEAMID.com.you.shared',      // iOS: Keychain access group
);

What each platform does

	Android (multiProcess: true)	iOS (appGroupId)
Regular	MultiProcessDataStore in its own file	UserDefaults(suiteName:) App Group
Secure	Encrypted MultiProcessDataStore (native_datastore_secure_mp.json)	appGroupId used as the Keychain access group

⚠️ Important details

• Separate file on Android. The multi-process store uses its own file, so values in the default single-process store are not migrated into it. Set configure before your first read/write.
• iOS appGroupId means different things per store. For the regular store it's an App Group suite name (e.g. group.com.you.app, App Groups capability). For SecureDatastore it's a Keychain access group (often team-prefixed, e.g. $(AppIdentifierPrefix)com.you.shared, Keychain Sharing capability). They are different strings — you can't pass the same value to both.
• Enable the capability in Xcode (App Groups and/or Keychain Sharing) for iOS sharing to work.

Do I even need this?

Only if your app runs code in a separate process / extension. Symptoms of multi-process misuse on the default store: silently lost writes, "old" values reappearing after upgrade, or CorruptionException. If everything runs in the main Flutter process, you don't need configure.

Full write-up: Multi-process access.