Hi - I’m a generally tech literate person up until the Terminal comes out. I’ve been trying to integrate my Apple tools and apps with CoWork via MCPs etc. I came across this app called Macuse which looks like it could reduce my headaches, but I don’t really ‘get’ how it works as a separate app rather than an MCP, whether I need to know that anyhow, and whether there’s anything I should be concerned about. It looks pretty simple, easy and friendly, like my dog.
Would love to get some thoughts from the resident techs. Thx.
I have no affiliation with Macuse and had never heard of it until your post. However, with a quick perusal of the documentation, it appears to work in two ways.
First, through App integrations, is works directly on your app data. Consider Calendar.App; you can install Fantastical and/or BusyCal on your Mac and access/read/edit the same calendar data. Any edits in one app will appear in the others. Macuse is just another app which accesses/edits the same data (with permissions that you grant). However, rather than a GUI (graphical user interface) or CLI (command line interface) for humans to interact with, it presents a machine interface (MPC server) for AI to interact with. All of the supported apps are listed here.
For interacting with other apps, it presents an automation layer (called Computer Use) which controls the keyboard and mouse to click and type its way around the app. Again, this is similar to existing automation apps except it presents a MPC server interface for AI to interact with. This appears to rely on having permissions to take screenshots. Presumably the AI is analyzing the screenshots and determining where to instruct Macuse to click the mouse, etc.
When I searched “Macuse” the first result was a GitHub account with source code. However, that only appears to be the MPC server itself. All server requests are passed on to a closed source binary, so there is no way of knowing what they are actually doing behind the scenes. However, based on the documentation, we can make a few assumptions.
The documentation makes is clear that for the app to work, you must give the app full read/write permissions for all of the relevant data. In other words, you must trust the developers with your data. Their website indicates that your data stays on your machine. Each potential customer will need to make their own determination of whether to trust that claim. I have no inside knowledge and can’t help with that.
With some data (like calendars) Apple provides an official API for other apps to access it. Based on the permissions that Macuse requires, it would seem that they are using those APIs. However, other apps (like Notes) do not have an official API and so developers have reverse engineered the data structure and read/write the raw data directly. Again, based on the permissions that Macuse requires, this seems to be what is happening here. There are existing apps which have successfully done this without corrupting your data. However, with a future update, Apple could change the data structure without warning and things could break in various unpredictable ways. It all depends on what kind of safety checks the developers put in place. Without access to Macuse’s source code, we have no way of knowing what protections they have built in, if any.
The good news here is that, according to the documentation, one could give permissions to some of the app integrations, but not others. Therefore, one could enable access to a limited subset of data for testing and gradually build up trust over time—or have your trust destroyed and delete the app with only limited damage to your data. As I have not used the app, I can’t make any recommendations one way or the other. I have just reported what I have deduced from reading the documentation.
Thank you for such a comprehensive, clearly presented outline. It really gives me a strong sense of what’s going on behind the scenes.
It seems a few of these types of apps are now popping up, as they would be attractive to people like me who want things to sometimes ‘just work’. There’s one called Orchard, another called Claunnector. Maybe Apple will announce something in June that will take care of this side of things.
Hi, I’m the developer of Macuse. Found this thread from referral traffic, thanks for the discussion.
@waylan’s analysis is basically correct. Quick note on data safety: for apps with an official Apple API (Calendar, Reminders, Contacts) we use those directly. For apps without one like Notes and Mail, reads come from local files but writes always go through AppleScript, so the app itself does the mutation. No risk of us corrupting the underlying store.
Would love Apple to solve this in June, but I’m pessimistic. That’s why I built Macuse. Happy to answer questions.
Thanks for the suggestion! I tested Claunnector, the seemingly most conservative option, since it can’t control the computer directly and logs all its actions in a console. The experience was pretty solid. Claude also confirmed that EventKit is what keeps it fast and accurate.