If I fetch a library playlist like the generated "Favorites" playlist via MusicKit like this guard let initialTracks = try await playlist.with([.tracks]).tracks else { return nil } I get a list of tracks like this: ... TrackID: i.e5gmPS6rZ856 TrackID: i.4ZQMxU0OxNg0 TrackID: i.J198KH4P85K4 TrackID: i.J1AaRC4P85K4 TrackID: i.4BPqWt0OxNg0 TrackID: 4473570282773028026 TrackID: 4473570282773028025 TrackID: 4015088256684964387 TrackID: 4473570282773028024 TrackID: 7541557725362154249 TrackID: 4473570282773028027 I save the IDs for later use, but when I want to fetch them, only the ones with ids that starts with "i." work. static func getLibrarySong(from id: String) async -> Song? { var request = MusicLibraryRequest<Song>() request.filter(matching: \.id, equalTo: MusicItemID(id)) do { let response = try await request.response() return response.items.first } catch { ... } } Or the Apple Music API endpoint : static func getLibrarySongFromAPI(with id: String) async -> Song? { guard let url = AppleMusicURL.getURL(for: .getSongById, id: id) else { return nil } do { let dataRequest = MusicDataRequest(urlRequest: URLRequest(url: url)) let dataResponse = try await dataRequest.response() let response = try JSONDecoder().decode(SongsResponse.self, from: dataResponse.data) return response.data.first } catch { ... } } Both functions above won't work for the non numeric like 4473570282773028024 so it seems the ID is wrong, but how do I make it work? Otherwise I can fetch all the songs fine, in catalog or in the library, but these few songs can't be individually fetched, only with the try await playlist.with([.tracks])` fetch, that gets the whole playlist. But obviously this isn't always possible. Thanks in advance!

When I tried to use a working project with iOS 18 installed on my device, it wouldn't work anymore and crash right away. Before with iOS 17 it was working fine. I can't access child variables that are saved in an Array in a parent object in SwiftData. The error is always somewhere in these hidden lines: { @storageRestrictions(accesses: _$backingData, initializes: _title) init(initialValue) { _$backingData.setValue(forKey: \.title, to: initialValue) _title = _SwiftDataNoType() } get { _$observationRegistrar.access(self, keyPath: \.title) return self.getValue(forKey: \.title) } set { _$observationRegistrar.withMutation(of: self, keyPath: \.title) { self.setValue(forKey: \.title, to: newValue) } } } The child classes are also inserted and saved into the modelContext when created and set to the parent instance, but I also can't fetch them via modelContext.fetch() - Error here is: Thread 1: EXC_BREAKPOINT (code=1, subcode=0x243a62a4c) Maybe there is a problem with the relationship between two saved instances. The parent instances are saved correctly and it was working in iOS 17. The problem is similar to these two cases: https://forums.developer.apple.com/forums/thread/762679 https://forums.developer.apple.com/forums/thread/738983 I changed the logic after I reviewed these threads, as I am now linking the parent and child instances, that got rid of one warning in the console. button.canvas = canvas modelContext.insert(button) canvas.buttons = [button] But in the end those threads were not enough for me to find a fix for my problem. A small project can be found here: https://github.com/DonMalte/SwiftDataTest

I am trying to offer my users a wide variety of playlists, like Apple Music does in the "explore" section. I fetched the charting playlists for the current storefront, but that's as far as I get. For example, I fetch the top charts genres first. If a user selects a genre I want to display the playlists for this genre, so I call the charts endpoint with the genre as the id but I can't get a response. path = "/v1/catalog/\(storefrontID)/charts" components.queryItems = [ URLQueryItem(name: "types", value: "playlists"), URLQueryItem(name: "chart", value: "most-played") ] if let id = id { let genreQuery = URLQueryItem(name: "genre", value: id) components.queryItems?.append(genreQuery) } Even weirder, I get exactly one genre "Musik" (which isn't a genre) with identifier "34" and storefrontId "de" where it works and I get my playlists. All other genre return empty responses. I try to use AppleMusic API with MusicKit as an addition, but there doesn't seem to be a solution for this problem either.