You might have noticed assistantd and assistant_service while using Activity Monitor and wondered what they are. Well, don’t panic: these process are both part of macOS, and help make features like Siri and dictation possible.
This article is part of our ongoing series explaining various processes found in Activity Monitor, like kernel_task, hidd, mdsworker, installd, WindowServer, blued, launchd, backup, opendirectoryd, and many others. Don’t know what those services are? Better start reading!
Today’s processes aren’t particularly well documented—there isn’t even a man page for either of them. But with some testing, we can confirm that they both come with macOS, and are both related to Siri and Spotlight’s knowledge base.
First of all, both services’ CPU usage goes up just a little bit when Siri is invoked, or when Spotlight is searched for something like a contact or calendar appointment. Second, both processes live in /System/Library/PrivateFrameworks/AssistantServices.framework/—a bundle that includes icons for Siri, among other things directly related to the virtual assistant. Third, Activity Monitor confirms that these processes are accessing things like Contacts and Calendar appointments, which are exactly what Siri needs in order to look up email addresses and your schedule.
So while we can’t confirm what exactly these processes are doing, we can say with confidence that they’re a legitimate part of macOS, and that they’re related to Siri and Spotlight.
Some users have reported assistantd asking for access to things like Contacts every time they invoke Siri. Giving assistantd the requested access should stop these notifications from happening.
These two processes shouldn’t spike CPU usage, but if they do consider disabling Siri entirely. It should help.