import Foundation

final class BGSession: NSObject, URLSessionDownloadDelegate {
  static let shared = BGSession()
  lazy var session: URLSession = {
    let config = URLSessionConfiguration.background(withIdentifier: "com.example.bg")
    config.isDiscretionary = true
    return URLSession(configuration: config, delegate: self, delegateQueue: nil)
  }()

  func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask,
                  didFinishDownloadingTo location: URL) {
    // Move file from temporary location to a permanent URL
  }
}

                    

import SwiftUI
import Foundation

struct ContentView: View {
  var body: some View {
    VStack(spacing: 12) {
      Text("Background Session Config")
      Button("Start sample download") {
        let url = URL(string: "https://example.com/file.dat")!
        BGSession.shared.session.downloadTask(with: url).resume()
      }
    }
    .padding()
  }
}

                    

import SwiftUI

@main
struct MyApp: App {
  var body: some Scene {
    WindowGroup { ContentView() }
  }
}