Macmon Bar

Macmon Bar is a native macOS menu bar monitor for Apple Silicon Macs. It bundles a Rust metrics runtime based on the open-source macmon sampler and shows live CPU, GPU, memory, network, and power metrics directly in the menu bar.

Features

• Live menu bar text, graph, or combined text-plus-graph display
• Configurable menu bar metrics: CPU total, P-CPU, E-CPU, GPU, memory, network, power, CPU power, and GPU power
• Live settings previews for menu bar display styles
• Compact value-over-time charts in the popover
• Sampling interval controls with immediate feedback
• Background sampling at 1s, with faster sampling available while the popover is open
• Bundled Rust runtime, so users do not need to install a separate CLI

Screenshots

Menu Bar

Settings

Requirements

• macOS 14 or newer
• Apple Silicon Mac

Install From a Release

For the first GitHub release, Macmon Bar will ship as a signed and notarized zip:

MacmonBar-1.0.0.zip

Download the zip from GitHub Releases, unzip it, and move MacmonBar.app to /Applications.

Build Locally

Clone the repository:

git clone https://github.com/mark-x64/MacmonBar.git
cd MacmonBar

The app builds its bundled runtime from MacmonBarRuntime/. The macmon submodule is kept only as an upstream reference and is not required for normal local builds or releases.

Build and run the app:

cd MacmonBar
make app
open dist/MacmonBar.app

Development commands:

make test
make bump-build
make run
make app

Release Versioning

Macmon Bar uses semantic versions: MAJOR.MINOR.PATCH.

• Patch: increment by 1 for small fixes, visual polish, performance tweaks, dependency updates, or release-process fixes that do not materially change the product surface. Example: 1.0.0 -> 1.0.1.
• Minor: increment for larger UI changes, new settings, new visible metrics, or meaningful feature additions. Reset patch to 0. Example: 1.0.3 -> 1.1.0.
• Major: increment only after explicit maintainer confirmation. Use this for breaking changes, major architecture changes, a major minimum macOS version change, or a product direction reset.

CFBundleVersion is the build number and increases by 1 for every successful app bundle build, regardless of whether the semantic version changes by patch, minor, or major.

Signing and Release

Release signing is documented in RELEASING.md. In short:

1. Build the app bundle.
2. Sign the bundled runtime binary and then MacmonBar.app with a Developer ID Application certificate.
3. Notarize the signed app with Apple's notary service.
4. Staple the notarization ticket.
5. Create a zip and upload it to GitHub Releases.

License

Macmon Bar is released under the MIT License. See LICENSE.

Macmon Bar bundles MacmonBarRuntime, a local runtime based on upstream macmon, which is also licensed under MIT. See THIRD_PARTY_NOTICES.md.