Discover appexes with AppexIndexer
App extensions, appexes, have become plentiful and widely used by macOS and third-party software, yet discovering and controlling them is patchy and limited. The most coherent access is in System Settings > General > Login Items & Extensions, where some are gathered in the list of Extensions at the end. Others like Safari extensions are controlled in app settings, while most remain hidden out of sight.
To take stock of all these appexes, I turned to the pluginkit
command tool, but the lists it generates are seemingly ordered at random, and so extensive that it would require some serious scripting to make any sense. Instead, it’s easier and more effective to put together a little app to do that. So I present you with AppexIndexer, an exploratory utility that displays key information about all appexes recognised by macOS.
Click on its button to Get Appexes and the window below will fill with well over 400 items, arranged in alphabetical order by the first entry in each line, the SDK or NSExtensionPointIdentifier. Some of those should be fairly obvious: for instance, those appexes listed in Photos Editing settings use the com.apple.photo-editing
SDK. In a future article I will explore the relationships between settings categories and SDKs given.
Following that comes the display name of that appex, again ordered alphabetically within that SDK group, which should be the same as that used in System Settings. Next comes the path to that appex, so you can inspect it and its Info.plist for further information.
Many appexes also have a parent, so the last two entries given are the name and path to that parent, when they’re available. One quick way to recognise third-party appexes is to glance down the right side of the list, as they invariably have a familiar parent. Appexes built into macOS are far less likely to have parents (and you can read into that what you like!).
Even in a modest installation, you’re likely to see well over 400 in your Mac’s list, from SpamSieve, an Email Extension with the SDK of com.apple.email.extension
, through to QuickLook thumbnail previewers, screensavers and wallpaper. I’ve already explained in general terms what these are and how they work, in this article.
One significant feature missing at this stage is Find/Search, which I’m still working on, for LogUI as well. There’s also additional information given by the pluginkit
command tool, and more still that’s available from each appex’s Info.plist file inside its bundle. This initial release lets you save the window’s contents using the Save as RTF button, and you can copy any selected entries and paste them as text. Row selection can be continuous using the Shift key, and discontinuous using Command.
Appexes are not only growing in number, but also becoming increasingly important in macOS. In some cases, they include background processes that could be used maliciously as a method of persistence. Although appexes still need to comply with TCC’s strict rules for accessing protected services and data, they can be an effective way to fly under a user’s radar.
AppexIndexer 1.0 build 5 is now available from here: appindexer105
I’m afraid that it requires macOS Sonoma 14.6 or later, to support the features it uses in SwiftUI.
I hope that you find this information of use. Please let me know what features you’d like the app to support, whether you’d like it to access appex property lists, or other useful data, and how you might want to use a future version. While I’ve got my own ideas, I’m interested in yours, and will try to accommodate them.