First step is to confirm that your decoration is added with "fileproviderctl evaluate " Then make sure that the decoration is listed as a NSFileProviderDecorations in Info.plist

You can always send a notification to your fileprovider and call signalEnumerator to trigger a new enumeration. Then your enumerator returns the changes.

You can easily add an emboss icon as decoration like this: Decorations: com.cihub.cihubdrive.CIHubDriveFileProvider.aemFolder: "aem Folder" Then add your emboss icon in Info.plist

Thanks for your answer. The distinction I am making is between the arbitrary itemIdentifier field that I am managing in my workingSet and the internal fileprovider item id that starts with __fp/fs/fileID... I have no way to link the internal fileprovider ID to my own workingSet ID so my only workaround right now is to use the path which is not good. What I find pretty strange is that the NSFileProviderCustomAction performAction call in the main fileprovider extension receives the right itemIdentifier while the prepare call in the FPUI module receives __fp/fs/fileID... IDs which are useless. And yes you are correct that this is indeed the ID I am using with the getUserVisibleURL to get the path but evidently it seems that it might be able to work with both kinds of IDs.

I got the exact same issue but I think the problem is that the "didEnumerate" calls do not trigger Finder / fileproviderd to process each chunk of files so they are only taken in account at the very end of the enumeration cycles when finishEnumerating gets called. Some of my enumeration have several thousands items so it can take several minutes to enumerate and then an other several minutes after finishEnumerating is called to display in Finder ( as you found out ). Question is how to trigger fileproviderd to take each chunk of items in account when calling observer.didEnumerate ?

Managed to get it working with random icons with this in the Info.plist in the main app bundle <dict> <key>UTTypeConformsTo</key> <array> <string>com.apple.icon-decoration.badge</string> </array> <key>UTTypeDescription</key> <string>Stared Item</string> <key>UTTypeIconFile</key> <string>mvstar.icns</string> <key>UTTypeIdentifier</key> <string>com.sk.mvapp.xxxxxFP.Provider.star</string> </dict> Then add the icns file in the xcasset or the main app folder Also double check that your file really has the decoration tag with fileproviderctl evaluate