What are coreservicesd, launchservicesd, and appleevents?

2006-06-05 17:00

These are some of the oldest and most basic processes on macOS. They have been part of the system since the early days of Mac OS X.

What is coreservicesd?

coreservicesd is the Core Services daemon. It manages file type links, Uniform Type Identifiers, and other low-level system functions. It is always running.

What is launchservicesd?

launchservicesd (shown as coreservices.launchservicesd) is the Launch Services daemon. It manages:

App registration: knowing which apps are installed and where they live
File links: deciding which app opens which file type (for example, double-clicking a .pdf opens Preview)
App launching: handling requests to open apps and files
Recent Items: tracking recently opened documents and apps
Default apps: managing your choice of default web browser, email client, and so on

If a file keeps opening in the wrong app, Launch Services is what you need to fix. You can rebuild its database:

/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Support/lsregister -kill -r -domain local -domain system -domain user

What is appleevents?

coreservices.appleevents handles Apple Events, the system that lets apps talk to each other. It powers AppleScript and Shortcuts. When one app tells another to do something (for example, a script telling Safari to open a web address), Apple Events carries the message.

Do they use many resources?

launchservicesd can use a burst of CPU when rebuilding its database, such as after installing many apps or after a macOS update. coreservicesd and appleevents are normally light.

Should you worry?

No. These are basic macOS processes that have been running on every Mac for over twenty years.

Enjoyed this post?

Well, you could share the post with others, follow me with RSS Feeds and/or send me a comment via email.