MacTelemetry

A lightweight macOS menu-bar app that monitors your Mac's thermal pressure, CPU usage, memory, and storage — with live graphs and throttling alerts. No admin privileges, no helper daemon.

Features

• Thermal pressure in the menu bar (nominal / moderate / heavy / critical), read from the system's true 5-level signal
• CPU temperature read from the SMC, with automatic discovery of every hardware sensor
• CPU usage and memory usage + pressure indicators with live 10-minute graphs
• Fan speed on Macs with fans
• Sensor browser — see every sensor, pick which drive the headline temperature
• Max-vs-average temperature, °C/°F, configurable refresh interval, detachable graphs window
• Real CPU speed-limit / scheduler-limit readout on Intel Macs
• Configurable throttling notifications
• Launch at Login

Requirements

• macOS 15.0+ (Sequoia)
• Apple Silicon or Intel

Install

The app is ad-hoc signed but not notarized yet, so macOS quarantines it. Clear the flag once after installing (this is a one-time step).

Homebrew

brew install --cask ishaanpilar/tap/mactelemetry
xattr -dr com.apple.quarantine /Applications/MacTelemetry.app

Download

1. Download MacTelemetry-x.y.z.dmg from Releases, open it, and drag MacTelemetry to Applications.
2. Clear the quarantine flag once, in Terminal:

   xattr -dr com.apple.quarantine /Applications/MacTelemetry.app

   Or without Terminal: double-click the app, dismiss the "could not verify" prompt, then open System Settings → Privacy & Security, scroll to Security, and click Open Anyway.
3. Launch it — the vitals icon appears in your menu bar.

On recent macOS, right-click → Open no longer bypasses this, and Homebrew removed the --no-quarantine flag — the xattr command (or Open Anyway) is the reliable way until the app is notarized.

Build

Open MacTelemetry.xcodeproj in Xcode and press ⌘R, or:

xcodebuild -project MacTelemetry.xcodeproj -scheme MacTelemetry -configuration Release build

How it works

• Thermal pressure — the Darwin notification com.apple.system.thermalpressurelevel (the same 5-level source powermetrics uses), read without root.
• Temperature / fan — read directly from the SMC over IOKit; all T* sensor keys are enumerated and cached, with an IOHIDEventSystem fallback.
• CPU usage — host_statistics(HOST_CPU_LOAD_INFO), sampled as tick deltas.
• Memory — host_statistics64(HOST_VM_INFO64) (App + Wired + Compressed), swap via vm.swapusage, pressure via kern.memorystatus_vm_pressure_level.
• Intel throttle — pmset -g therm (Intel only; skipped on Apple Silicon).

SMC sensor-key tables are derived from the Stats project.

License

MIT © 2025 Ishaan Pilar