A crash is exactly that, the app crashes immediately. When an error is thrown the app continues to run and can handle the error

Hi My question had nothing to do with the assert, I just wanted to understand the code better since the non-generic version worked and now I understand it better. I don't know if you are interested in testing this but I was thinking that maybe it's the associated type that causes the issues so one alternative to get would be to use MyModelProtocol instead for the generic type func addRecord<T: MyModelProtocol>(_ someDTO: T, recordName: String) async throws { ... }

When I tested this I didn't use model(for:) since I already had access to the object and then isDeleted was set to true after the deletion. This looks like an issue with SwiftData that. you might want to file a report about but as far as real world programming goes your example code looks quite contrived and I don't see why you would want to do something like this.

That’s correct, you can’t use the unique constraint together with iCloud. I guess you need to add your own check to see if you need to do an insert or an update.

If all code is in the original post then you have no place where you create your ModelContainer instance