airstats

An ultra lightweight macOS system monitor.

AirStats is a system monitor for the Mac menu bar. It reads CPU, memory, GPU, network, disk, battery, temperature, process and host statistics from the kernel and shows them in three places: the menu bar itself, a panel that drops down when you click the status item, and a desktop widget you can leave on screen.

It is built to be genuinely light. A menu bar monitor runs all day, every day, so AirStats holds a few megabytes and a fraction of a percent of one core rather than the tens of megabytes its peers take. It has no Dock icon, and reads the system through Mach, IOKit, sysctl and CoreWLAN.

Requirements

• macOS 14 or later
• Intel or Apple silicon

Install

Download it from airstats.app, open the dmg and drag the app to Applications. The release includes both Intel (x86_64) and Apple silicon (arm64) builds in one app. It is signed and notarized, so it opens with no warning.

Or with Homebrew:

brew install --cask airstats

AirStats updates itself with Sparkle. It asks airstats.app once a week whether a newer version exists, and installs one only when you say so. Both of those can be turned off in General settings.

Build from source

The universal build has been verified with Xcode 27 on Apple silicon. Older Xcode and macOS build environments may work, but have not been verified. The macOS 26 SDK enables Liquid Glass; builds with an earlier SDK use AirStats' existing material and sheen fallback.

Scripts/build.sh release
cp -R .build/release/AirStats.app /Applications/
open /Applications/AirStats.app

Scripts/build.sh builds both architectures, wraps them in one universal .app bundle, copies Sparkle.framework into Contents/Frameworks, and signs it ad hoc. macOS grants a status item only to a signed bundle with LSUIElement set. Run the script with no argument for a debug build.

An ad-hoc signature is enough to run a build you made yourself, and not enough to travel: macOS refuses an ad-hoc bundle that arrived over the internet. Scripts/release.sh is what produces the download above, signing with a Developer ID certificate and stapling Apple's notarization ticket to the .dmg.

Source layout

Path	What lives there
Sources/AirStatKit	Collectors, the sampling engine, settings, formatting. No UI.
Sources/AirStatUI	Menu bar drawing, panel, desktop widget, settings window, charts, design system.
Sources/AirStats	The executable, app delegate, and the probe and render commands.
Tests/AirStatKitTests	Contract tests for the collectors, plus settings and formatting.
Scripts/build.sh	Builds the binary and assembles the .app.
Scripts/release.sh	Signs, notarizes and packages the .dmg that ships.
Scripts/appcast.py	Writes a release into the appcast Sparkle reads.
Scripts/benchmark.py	Samples the menu bar monitors on your Mac over one shared window.

AirStatKit never imports SwiftUI or AppKit, which is what lets the tests and the probe run in a windowless process.

Contributing

CONTRIBUTING.md has the checks to run before a pull request and the house rules.

Contact

Bugs and feature requests go on the issue tracker. For anything private, email [email protected].

License

MIT. See LICENSE.