I think, The default configuration of SwiftData and CloudKit meets your needs

I want to print some logs in the production environment. I just randomly found a callback function and wanted to use it to print logs, but I found that data synchronization actually started working! What the hell is Apple doing? Why? I think this is indeed a bug in CloudKit.I think this is indeed a bug in CloudKit. In the development environment, whether there is the code for printing logs or not, data can be synchronized normally. var body: some Scene { WindowGroup { MainView() .frame(minWidth: 640, minHeight: 480) .environment(mainViewModel) .onAppear { printLog("MainView appear") CKContainer.default().privateCloudDatabase.fetchDatabaseChanges(since: nil) { result in switch result { case .success(let success): printLog("fetchDatabaseChanges success") case .failure(let failure): printLog(failure.localizedDescription) } } } } .modelContainer(for: [NoteRecord.self], inMemory: isInMemory) }