macOS processes › Security and privacy
What is amfid on Mac?
amfid, the Apple Mobile File Integrity daemon, helps macOS verify code signatures when programs launch. It's part of how your Mac makes sure apps haven't been tampered with.
What it does
When a program starts, the kernel checks its signature and asks amfid for help with cases it can't settle itself, such as validating certain entitlements or provisioning profiles. It's usually quiet, and most people never notice it.
Why it gets busy
- Launching many programs quickly, like during a software build or test run.
- Running lots of unsigned or locally signed tools, common for developers.
- Installing many apps at once.
Why is amfid using so much CPU?
amfid is busy when lots of programs are launching, often during software builds. It settles when the launches stop.
Is it safe to quit?
Programs can fail to launch while it's gone, and macOS restarts it.
The real amfid is at /usr/libexec/amfid.
How to calm it down
- If you're building software, the load ends when the build or tests stop.
- Avoid scripts that launch the same small program thousands of times in a loop where one longer-running process would do.
- Restart your Mac if it stays busy with nothing launching.
In SystemWatch
SystemWatch's History shows amfid rising and falling with your builds or test runs, so you can see the cost of launching many small programs.
