NanoStats

A lightweight, zero-dependency macOS menu bar monitor

Features

• Real-time Menu Bar Metrics — Stacked indicators for upload/download speed, CPU %, GPU %, RAM %, and temperature
• Drag-and-Drop Reordering — Customize the order of metrics in the menu bar via a floating panel
• Toggle Metrics — Enable or disable individual metrics with checkboxes
• Network Interface Selection — Auto-detect or manually select a specific network interface
• Speed Units — Choose between fixed KB/s, MB/s, or Mbps units
• Configurable Refresh Rate — 0.5s, 1s, 2s, or 5s polling intervals
• Session Totals — Track cumulative upload/download data since launch
• Launch at Login — Native SMAppService integration (macOS 13+)
• Invisible in Dock — Runs as a pure menu bar accessory (LSUIElement)

Requirements

• macOS 11.0 (Big Sur) or later
• Xcode Command Line Tools (xcode-select --install)
• Apple Silicon (arm64)
• Because the app is not notarized, remove the quarantine attribute before opening it and moving NanoStats.app to Applications:

xattr -d com.apple.quarantine ~/Downloads/NanoStats.dmg

Building

For detailed instructions on building the macOS app bundle, creating a .dmg installer, SPM development, and troubleshooting, see BUILD.md.

# Quick build command
./build_app.sh

Project Structure

Sources/NanoStats/
├── main.swift                  # App entry point
├── StatusBarController.swift   # Menu bar hub, preferences, menu setup
├── NetworkMonitor.swift        # Network I/O via getifaddrs / if_data
├── SystemMonitor.swift         # CPU, GPU, RAM, Thermal via host_statistics64 / IOKit
├── MetricComponent.swift       # MetricType enum with display names
├── IconProvider.swift          # Dynamic multi-metric image renderer
├── ReorderPanel.swift          # Drag-and-drop metric reorder panel
├── SpeedFormatter.swift        # Byte-rate formatting utilities
└── LaunchAtLogin.swift         # SMAppService wrapper

How It Works

Metric	Source
Network Speed	getifaddrs() + if_data (POSIX)
CPU Usage	host_statistics64 (HOST_CPU_LOAD_INFO)
GPU Usage	IOKit (IOAccelerator → PerformanceStatistics)
RAM Usage	host_statistics64 (HOST_VM_INFO64)
Temperature	ProcessInfo.thermalState

License

MIT LICENSE