I am developing an iOS camera app that can record video directly to external storage connected to an iPhone.
To detect whether an external USB storage device is connected and to obtain its URL, I am considering using AVExternalStorageDeviceDiscoverySession.
However, when checking support using AVExternalStorageDeviceDiscoverySession.isSupported, I observe that it returns true only on Pro model iPhones, and false on non-Pro models in my environment.
I have reviewed Apple’s official documentation, but I could not find any clear description of the supported devices or requirements (for example, whether this API is limited to Pro models or requires specific hardware capabilities).
I would appreciate any information regarding the following points:
①The actual requirements for AVExternalStorageDeviceDiscoverySession to be supported
- Device limitations (Pro vs non-Pro models)
- Hardware requirements (USB controller, external recording capability, etc.)
- iOS version dependencies
②Whether support for non-Pro models is planned in the future
Tested environments
- iPhone 16 Pro (iOS 18.7.1) → isSupported == true
- iPhone 16e (iOS 26.2) → isSupported == false
- iPhone 17 (iOS 26.2) → isSupported == false
- iPhone Air (iOS 26.2) → isSupported == false
If anyone has observed similar behavior or has official information from Apple regarding this API, I would greatly appreciate your insights.