This post is from the WWDC26 Networking Q&A.
With iOS 27's improvements to seamless Wi-Fi/cellular transitions, is there guidance for apps and frameworks doing background network requests on how to handle a transition mid-request? Do in-flight URLSession tasks survive a network path change automatically, or should apps build their own retry logic?
Typically, transitioning between Wi-Fi and cellular would not cause an ongoing task to fail since the system will keep the existing interface usable while preferring the new interface. If you're using background URLSession, the API will also automatically retry tasks as needed.
There should not be any additional changes for clients of the API to make.