What Is duetexpertd on Mac? 91 Wake-Up Triggers, 0.06% CPU

duetexpertd is the macOS process that makes predictions: which apps the App Library and Spotlight put first, which shortcuts get suggested, how notifications are grouped, and which Focus mode you are probably in. Its man page says only that it "powers personalized system experiences" and that "Users should not run duetexpertd manually." On my Mac mini it has used 1,269 seconds of CPU in 22 days, about 2 seconds an hour. That makes it the busiest process in its family and the 45th busiest of 713 on the machine, but still about 0.06% of one core.

The size of its launch file surprised me more than the CPU did. The LaunchAgent plist is 33,278 bytes and lists 91 separate events that can wake the process, including a CarPlay connection, a charger being plugged in and the clipboard changing. Below is what it is, what it did in one day, and what changed when I tried to make it busy.

The rig is a headless Mac16,10 (M4) on macOS 26.4.1 (25E253), up 22 days, with no Apple Account signed in, measured on 2026-10-20 as an admin user without sudo.

What duetexpertd is

$ ps -axo pid,user,etime,time,rss,comm | grep [d]uetexpertd
  978 sg-mini   22-00:12:35  21:09.38  52992 /usr/libexec/duetexpertd

$ man duetexpertd | col -b | sed -n '9,12p'
     duetexpertd powers personalized system experiences.

     There are no configuration options for this service. Users should not run
     duetexpertd manually.

launchd starts it from /System/Library/LaunchAgents/com.apple.duetexpertd.plist, so each logged-in user gets their own copy, running as that user. LaunchAgent vs LaunchDaemon explains why that matters. On this Mac it has started once, on 2026-09-28 at 11:47:52, and never exited.

The binary is small: 176,016 bytes, universal (x86_64 and arm64e), signed by Apple as a platform binary with the identifier com.apple.duetexpertd. The real code sits in the frameworks it links: AppPredictionClient, AppPredictionFoundation, AppPredictionInternal and ProactiveSupport, plus Intents and EventKit. The 25 Mach services it registers say the same thing in plainer words. Some examples: com.apple.proactive.AppPrediction.predictions, ActionPrediction.predictions, com.apple.proactive.appDirectory, com.apple.proactive.sleepSchedule, com.apple.personalization.notificationCategorization and com.apple.duetexpertd.ControlCenter. "ATX", which shows up all over its log, is the internal prefix for this app prediction code.

Its entitlements (132 of them) explain what it is allowed to read. The TCC allow list covers Calendar, Reminders, Contacts and CloudKit, and there are location entitlements for place inference and "locations of interest". In the log below it checked its current-location cache 241 times in a day. Its data folder, ~/Library/DuetExpertCenter, holds 41 entries, but even du gets "Operation not permitted" there. The usage history it learns from lives with knowledge-agent and the Biome streams. duetexpertd reads that history and turns it into rankings.

91 ways to wake it up

Most Apple agents list a handful of launch events. This one has 91, in four groups:

Event type	Count	Examples
notifyd notifications	51	CarPlayConnectedAnchor, ChargerConnectedAnchor, BluetoothConnectedAnchor, WiredAudioDeviceConnectedAnchor, now playing play/pause, pasteboard changed, calendar database changed
XPC activities (scheduled jobs)	26	everydayshortcuts, apppredictionupdate, biomepruning, focusMetricsLogging, verticalmodelstraining
Background system tasks	7	atxtrain, anchormodeltraining, magicalmoments, mode-entity-model-training, datastoremaintenance
Distributed notifications	7	LaunchServices applicationRegistered / Unregistered / StateChanged

The "anchor" events are the core idea. An anchor is something that happens just before you usually open a certain app: plugging in headphones, connecting to a car, ending an idle period. duetexpertd learns which apps follow which anchors and gets ready to suggest them. A headless Mac mini in a cupboard has no car, no headphones and no battery to charge, so most of these triggers never fire here. The scheduled jobs still run.

What it did in 23 hours

I pulled every unified log line from the process with /usr/bin/log show --predicate 'process == "duetexpertd"' (the zsh log builtin gets in the way; the log show command covers that). Full detail only went back 23 hours, to 2026-10-19 12:04: 19,722 lines, of which 1,745 were errors and 383 were faults.

The pattern has three layers. Odd hours are quiet, 45 to 69 lines, mostly the hourly everydayshortcuts job. Even hours carry 530 to 858 lines, which lines up with a suggestion "blending" refresh about every two hours. Then there are five spikes of 1,970 to 3,143 lines.

The XPC scheduler log shows which jobs actually ran. 23 of the 26 activities started in the window: everydayshortcuts 21 times, apppredictionupdate 10 times, updateAssetMetadata twice and the other 20 once each. Their handlers took about 6.1 seconds combined, and the longest was focusMetricsLogging at 1.7 seconds. Six of the seven background training tasks, including atxtrain and magicalmoments, were launched within two minutes of each other at 12:47 on Oct 19 and marked complete in the same second they started.

The 23:00 spike is the odd one. 931 of its 3,143 lines are the same warning: Unexpected NULL isEnterpriseApp for bundleId: com.apple.loginwindow. That fits a nightly pass over every app record. The other spikes are mostly blending-cache lines, Biome file reads and LaunchServices lookups (_LSBundleCopyOrCheckNode: cached node not found, 955 times in the day).

The errors are other processes' errors

Most of the 2,128 error and fault lines come from problems that are not really duetexpertd's:

• 375 x Couldn't read values in CFPrefsPlistSource ... (Domain: com.apple.triald ...). The sandbox blocks it from reading the trial system's preferences. I counted 127 of these refusals in one hour while writing about cfprefsd.
• 330 x 2 isValidFrame failed on the Biome App.Intent stream. This is the same damaged segment that knowledge-agent skips every night.
• 429 x Event class '<private>' missing from NSKeyedUnarchiver allowedClasses, from Biome's decoder.
• 23 x a failed iCloud Family query, which is expected on a Mac with no Apple Account.

None of these came with extra CPU that I could measure. If your Console is full of duetexpertd errors, that alone is not a sign that anything is broken.

Trying to make it busy

One thing I could test: duetexpertd listens for apps being registered, and the log showed five applicationRegistered events handled between 09:00 and 11:00 that morning. So I forced LaunchServices to re-register Calculator and watched CPU time and log volume, after a two-minute control period with no action.

LS=/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Support/lsregister
$LS -f /System/Applications/Calculator.app

window                      CPU time        log lines
control, 120 s              1269.38 → 1269.38     0
1 re-register, 120 s        1269.38 → 1269.38     8
3 re-registers, 120 s       1269.38 → 1269.39    21

Each registration produced a few log lines and about 0.01 seconds of CPU. App installs are not where the time goes, at least not here. Three CPU snapshots across the past day agree with each other: 1,238.4 seconds at about 21:00 on Oct 19, 1,266.2 at 10:31 on Oct 20 and 1,269.4 at 12:07. That works out to roughly 2 seconds an hour whether or not anything happens. In the six minutes I watched it closely, it used one hundredth of a second. The CPU comes in short bursts I did not catch, most likely the blending refreshes and the nightly pass.

When people see it at 100% or more

My numbers are from an idle Mac with no account and no apps in daily use. That is close to the best case, and other people see something very different. In an HN thread last week, one user wrote that duetexpertd "was trying to use nearly two full cores" on a months-old MacBook with iCloud off and no iPhone (HN). Another commenter answered that daemons like it "should be running at a low QoS" and that if it interrupts apps, "you've found a bug. You can report it with Feedback Assistant" (HN). A developer debugging stalled unit tests on an M4 Pro wrote down that during the bad period the load average was 30 to 95, with mds, duetexpertd and PerfPowerServices all busy (romper #666). In another project's bug report, a user ruling out causes noted "no duetexpertd / Siri processes busy" (exo #2375), so it is evidently one of the first things people check.

What I would do if it were hot on my machine, in order:

1. Check that it is the real one: codesign -dv /usr/libexec/duetexpertd should print Identifier=com.apple.duetexpertd and a Platform identifier. A copy anywhere else is worth a closer look.
2. Capture what it is doing while it is busy: sample duetexpertd 10 works without sudo, because the process runs as you (I checked: a 1,157-line report with Version 627.11), and that output is what makes a Feedback Assistant report useful.
3. Cut down what it learns from. Apple's Siri settings page describes App Access as the place to "choose the apps you want Siri to learn from and show Siri suggestions for".

I would not unload it with launchctl. It registers 25 Mach services, with names for app prediction, the App Library, Spotlight suggestions, Control Center and notification categorization, and launchd starts it again whenever one of them is called. On this Mac there is nothing to win back: about 50 seconds of CPU a day, and mediaanalysisd used almost eight times as much (9,959 seconds) over the same 22 days.

FAQ

What is duetexpertd on Mac?

duetexpertd is a macOS system process at /usr/libexec/duetexpertd, started per user by /System/Library/LaunchAgents/com.apple.duetexpertd.plist. It runs Apple's app and action prediction code (ATX): it ranks apps for the App Library and Spotlight, suggests shortcuts, categorizes notifications and infers Focus modes, using usage history stored by knowledge-agent and Biome.

Why is duetexpertd using so much CPU?

It retrains prediction models and refreshes suggestions in bursts, on a schedule and after events such as app installs or device connections. On an idle test Mac mini it averaged about 2 seconds of CPU per hour. Sustained use of one or more full cores is not normal background behavior; capture it with "sample duetexpertd 10" and report it through Feedback Assistant.

Can I disable duetexpertd?

Apple gives no setting to turn the process off, and its man page says it has no configuration options. You can limit which apps Siri learns from under App Access in Siri settings. Unloading it with launchctl is not recommended, because it provides 25 Mach services to other system components and launchd starts it again on demand.

Measured on 2026-10-20 on one headless Mac mini (Mac16,10, M4, macOS 26.4.1 build 25E253, up 22 days), no Apple Account signed in, as an admin user without sudo. CPU figures come from ps at three points in time, launch events and Mach services from the LaunchAgent plist, linked frameworks from otool, entitlements from codesign. Log figures come from one /usr/bin/log show capture of the duetexpertd process covering 23 hours (19,722 lines). The re-registration test used lsregister on Calculator with a two-minute control window. I did not open ~/Library/DuetExpertCenter, run sample during a spike, or change any setting. User reports are from one HN thread and two GitHub issues; the only Apple documentation is the man page and the Siri settings page.