How app can access files on USB OTG storages in Android 6.0 (API level 23) without root?

Question

Android 6.0 Developer Preview (API level 23) can natively mounts external removable USB OTG storages out-of-the-box without any additional apps (for more info please see: ht

Answer 1

Since Android 6, according to the USB Media Support documentation, the Storage Access Framework seems to be the only available mecanism:

In Android 6.0, any device that is not adopted is considered portable. […] Third-party apps must go through the Storage Access Framework to interact with files on portable storage; direct access is explicitly blocked for privacy and security reasons.