Alerts

The alerts that the rules wrote, and how to set the rules.

The helper checks rules while it records, also when the app is closed. When a value passes a rule’s threshold, the helper writes an alert. The Alerts screen lists them, newest first.

The Alerts screen: a table of warnings with time, subject and message, and a footer with the counts of the last 7 days — Alerts as a table: severity, time, subject and message. An alert about the Mac names a likely cause.

The table

Column	What it shows
Severity	A triangle for a warning (yellow) or an octagon for critical (red).
Time	“Today, 15:42”, “Yesterday, 22:31”, or else the date.
Subject	The app, or for a rule about the Mac, what the rule watches: CPU, Memory Pressure, Swap and so on.
Message	What happened, for example “CPU at 72 % of all cores for 5 min: node used 12 % of all cores”.

Right-click an alert for Dismiss, Restore and Copy Message.
Dismiss All, in the toolbar, dismisses the alerts shown. It does not ask first, because you can restore them. View > Show Dismissed Alerts shows them again.
The sidebar shows the count of unread alerts.
The footer shows the last 7 days as bars by severity, then today’s count, the critical and warning counts of the 7 days, and the most frequent subject.

Rules

Rule	About	Alerts when
Sustained CPU	Each app	An app stays above a CPU level for a time.
Memory Growth	Each process	A process grows steadily by an amount over a time.
Memory Jump	Each process	A process grows by an amount in under a minute.
Disk Writes	Each app	An app writes an amount to disk in one hour.
Network	Each app	An app receives and sends more than a rate for a time.
Energy Impact	Each app	An app stays above an energy impact for a time.
GPU	Each app	An app stays above a GPU use for a time.
System CPU	The Mac	The CPU of all cores stays above 70 % (warning) or 90 % (critical) for 5 minutes, by default.
Memory Pressure	The Mac	Memory pressure reaches a level.
Thermal State	The Mac	The thermal state stays at or above a level for a time.
Swap Used	The Mac	Swap passes a share of the memory.
Free Disk Space	The Mac	Free space on the startup volume falls below a level.

After an alert, a rule is quiet for a time, so one problem does not give many alerts. Settings shows each rule’s quiet time under its values. An alert about the Mac names a likely cause, for example the process whose memory grew most.

Set the rules

Open Settings > Alerts.

Preset: Relaxed, Balanced (the default) or Strict. A preset calculates the values for your Mac from its cores, its memory and the size of its startup volume. When you change a value, the preset becomes Custom.
App Rules and System Rules: each rule has a switch. Click a rule to edit its values.
Banners for: Critical Only (the default) or All Alerts. With Critical Only, a warning goes to Notification Center without a banner.

To give one app its own values, or to mute it, select the app and click Rules… in the inspector.

From Terminal

amx call events '{"kind":"alert","from":"-7d"}' prints the alerts of the last 7 days. See amx and MCP.