SUMMARY I know this might be a strange request, it's probably no match and most likely not worth the effort, but applications like kdeconnect could make use of the cache. Example: https://invent.kde.org/network/kdeconnect-kde/-/merge_requests/670 KApplicationTrader::preferredService alway returns an empty result on Windows. All the file and scheme handler associations are stored in the registry: HKEY_CLASSES_ROOT STEPS TO REPRODUCE 1. Use KApplicationTrader::preferredService on Windows OBSERVED RESULT Empty results. EXPECTED RESULT Results that are equal to the registry. SOFTWARE/OS VERSIONS Windows: 11