Mactivity

A lightweight system monitor that lives in the macOS menu bar.

Mactivity keeps the numbers you actually watch — CPU, GPU, memory, disk and network — one click away, and can show them inline in the menu bar itself. It is a single ~2 MB universal binary with no dependencies, no background daemon and no network access.

Features

• Menu bar readout — show CPU, memory, network or battery next to the clock, in a monospaced font that doesn't jitter as the digits change.
• At-a-glance panel — CPU, GPU, memory and disk as usage rings, with a 60-second history graph for each.
• Per-core load — a live bar for every performance and efficiency core.
• Memory detail — app, wired and compressed breakdown, live memory pressure.
• Top processes — the five heaviest CPU consumers, with the option to quit one from the list.
• Detachable widget — float the panel above other windows on any Space.
• Cleaning mode — disable the keyboard for up to two minutes so you can wipe it down without typing into anything.
• Customizable panel — choose individual gauges, details and history graphs in Settings → Main Window. Essentials shows CPU, memory and network speeds; Show all restores every section. Choices also apply to the floating widget.
• Dense layout, two-column history graphs, six accent colours, and Launch at Login.
• In-app updates — Mactivity checks for new versions once a day and can install one in place. Nothing is downloaded or replaced without asking.

Idle cost is about 1% of one core. With the floating widget visible and every graph updating once a second, it settles around 8%.

Requirements

macOS 14 (Sonoma) or later, on Apple Silicon or Intel.

Install

Download the latest Mactivity-x.y.z.dmg from the Releases page, open it, and drag Mactivity to your Applications folder.

The app is signed with a Developer ID and notarized by Apple, so it opens normally on first launch. Verify the download if you like:

shasum -a 256 -c SHA256SUMS.txt

Mactivity has no window of its own — after launching, look for the waveform icon in the menu bar.

Cleaning mode

Disable Keyboard in the settings pane blocks every key — including the function row — for the duration you pick, so you can wipe the keyboard down without typing into whatever is in front. A full-screen overlay shows what is happening and counts down.

The trackpad, mouse and power button keep working, so there is no way to get stuck: click Done, let the countdown run out, or quit Mactivity. The block also ends on its own if the Mac sleeps or the screen locks, and it lives entirely inside the running process — if Mactivity is killed or the Mac restarts, the keyboard comes straight back.

Blocking keys needs Accessibility access, which macOS asks for the first time you use cleaning mode; nothing else in Mactivity uses it. Keystrokes are discarded unread — they are never inspected, stored or sent anywhere.

Updates

Mactivity checks GitHub for a new release once a day and offers it in the settings pane; automatic checking can be turned off there, and Check for Updates is always available. Finding, downloading and installing an update are three separate, explicit steps — nothing is replaced behind your back.

An update is installed only if it is signed by the same Developer ID team as the copy you are running, carries the expected bundle identifier, passes Apple's notarization assessment, and is strictly newer than the installed version. A build failing any of those checks is discarded. If the replacement itself fails, the previous version is moved back into place.

Updating requires write access to wherever Mactivity is installed.

Usage notes

• Launch at Login only works for a copy in /Applications. macOS registers the login item by its location, so a build run from elsewhere cannot be registered.
• Quitting a process sends SIGTERM, letting it shut down and save. Hold Option while clicking to send SIGKILL instead, which is immediate but discards unsaved work.
• Quit Mactivity from the gear menu, or press Q while the panel is open.

Build from source

git clone https://github.com/elDoof/Mactivity.git
cd Mactivity
./build_app.sh --install

That produces MactivityMonitor.app, installs it to /Applications and launches it. Omit --install to leave the bundle in the working directory.

Building only the executable works with the Command Line Tools alone:

swift build -c release

A universal binary additionally needs a full Xcode install, since the two- architecture build goes through xcbuild:

UNIVERSAL=1 ./build_app.sh

Cutting a release

release.sh builds a universal, hardened, Developer ID-signed bundle, submits it for notarization, staples the ticket, and writes a .dmg, a .zip and SHA256SUMS.txt into dist/. It expects a Developer ID Application certificate in the keychain and a stored notarytool profile:

xcrun notarytool store-credentials "mactivity-notary" \
    --apple-id "you@example.com" --team-id "TEAMID" \
    --password "app-specific-password"

./release.sh

Set SKIP_NOTARIZE=1 to sign and package without submitting to Apple.

Project layout

Path	Contents
Sources/main.swift	AppKit entry point
Sources/AppDelegate.swift	Status item, popover, menu bar label
Sources/ActivityMonitor.swift	Statistics collection
Sources/ContentView.swift	Panel, floating widget, settings
build_app.sh	Bundle assembly and signing
release.sh	Signed, notarized release artifacts

Statistics come from the system directly — host_statistics, sysctl, IOKit registry properties, getifaddrs and IOPowerSources — rather than by shelling out, with the single exception of ps for the process list.

License

MIT