Thanks for the answer! Update: First, I've found out that i was packaging the .aar file using the "generic" xcrun ba-package package tool, instead of using the FoundationModels adapter-specific one, xcrun ba-package foundation-models package (found out from the adapter training toolkit source - produce_asset_pack.py), as the FoundationModels runtime recognizes only packs built with the FoundationModels tool. The issue is that the FoundationModels tool generates a manifest with the property onDemand set to null ("onDemand": null) , which gets rejected by Transporter when trying to upload it (I was getting ITMS-91140 - invalid manifest file). I tried extracting the .aar, changing null to {} in manifest.json, then repacking the .aar file with the archive command - after doing this, the upload via Transporter was successful and accepted in App Store Connect. The internal TestFlight delivery works and the statusUpdates stream fires all events correctly (.began/.downloading/.finished). Hope this will help anyone with this issue in the future!