MediaDeviceExtension is not launched; audiomxd logs “missing required entitlement” (iPadOS 27)

I'm trying to implement a MediaDeviceExtension, but it is not being launched. I followed the documentation, but I see "missing required entitlement" in log, even though I've added the entitlement.

My Setup

  • com.apple.developer.media-device-extension on both the app and the extension:
<key>com.apple.developer.media-device-extension</key>
<array>
    <string>media-device-protocol.myradio</string>
</array>
  • The same id is in the extension’s UTExportedTypeDeclarations → UTTypeIdentifier (conforming to public.media-sharing-protocol) and in the Swift protocolType property.
  • The app’s Info.plist has MDESupportedProtocols with the same id.
  • EXExtensionPointIdentifier = com.apple.media-device-extension in EXAppExtensionAttributes.
  • The capability is enabled on both App IDs in Certificates, Identifiers & Profiles.

Problem

Opening an AVRoutePickerView does not call startDeviceDiscovery(), and no device appears in the picker. Device log:

-FigCustomEndpointManager- manager_shouldAllowDiscoveryForProtocol:
    Protocol media-device-protocol.myradio has never been activated - allowing discovery for first-time use
-FigCustomEndpointManager- manager_SetDiscoveryMode:
    Failed to launch system casting instance for protocol media-device-protocol.myradio
-MXAppExtensionMonitor- -[MXAppExtensionInstance launchExtensionRequiring:]:
    Extension with identifier: <_EXExtensionIdentity: 0x…> is missing required entitlement, dropping!
-MXSystemMediaCasting- -[MXSystemCastingExtensionInstance launch]:
    Failed to launch <SystemMediaCastingExtension<MyRadio:media-device-protocol.myradio>: …,
    <EXExtensionProcess: (null) PID: 0>, 0>

Question

What entitlement is MXAppExtensionMonitor checking for when launching a SystemMediaCastingExtension? It is not named in the log. If an entitlement beyond com.apple.developer.media-device-extension is required, how is it obtained?

FB23043277

Note that I'm seeing the same issue when trying to implement this on an iPhone running iOS 27 beta. So this doesn't seem to be a iPad or device specific problem.

Would be great to understand what we can do to make this work!

MediaDeviceExtension is not launched; audiomxd logs “missing required entitlement” (iPadOS 27)
 
 
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