Plugin to write a file to a USB drive plugged into a phone

Capacitor
1

We have a use case where our app wants to download a text file from the cloud - got this working - but then write the text file downloaded from the cloud to a USB flash drive plugged into the phone device.

I saw this for iOS - Connect external storage devices to iPhone - Apple Support)%2C%20FAT32%2C%20or%20FAT.

“You can use the Files app and other supported apps to access files stored on external devices, such as USB drives and SD cards, connected to your iPhone.”

What constitutes a supported app?

Are there plugins that support this for both Android and iOS?

Thanks for any information.

2

A little more information. So far, I’ve tried the following plugins:

  • @capawesome/capacitor-file-picker
  • @capacitor/filesystem
  • @capacitor/share

Using FilePicker, I can successfully pick a file from the device’s internal storage. However, when I select the USB drive as the destination, the plugin returns a content:// URI (I believe Android uses the Storage Access Framework (SAF) for external drives).

From what I’ve gathered, none of these plugins support writing to content:// URIs, which means I can’t actually copy a file to the USB drive using these APIs.

Questions:

  1. Is my understanding correct — that Capacitor plugins do not currently support writing to content:// destinations like USB drives via SAF?

  2. Are there any workarounds?

  3. Any plans for Capacitor or community plugins to support this in the future?

Thanks!