A lightweight macOS menu bar app for live memory monitoring with an interactive pie chart.

• Memory usage with percentage ring (color-coded by pressure)
• Memory pressure indicator — Normal (green), Elevated (yellow), Critical (red)
• Free memory and compressed memory stats
• Updates every 1.5 seconds

Visual breakdown of system memory:

• App (blue) — Memory used by applications
• Wired (red) — Memory that can't be paged out
• Compressed (orange) — Memory compressed to save space
• Cached (yellow) — File cache (reclaimable)

• View top 8, 15, or 30 apps by memory usage
• Pie chart view — Visual breakdown with hover-to-inspect
• List view — Compact scrollable list for more apps
• Shows app icon, memory usage, thread count, and percentage
• Click any app for detailed process info

• Resident memory (actual RAM used)
• Virtual memory (address space)
• Thread count
• Open file descriptors
• Memory regions
• Page faults / page ins
• Parent PID
• Running time (uptime)
• Bundle ID and full path (copyable)
• Quick link to Activity Monitor

• Chart / List toggle — Switch between pie chart and list-only view
• 8 / 15 / 30 picker — Show more or fewer processes
• Mouse tracking on pie chart — hover to highlight slices

cd /Volumes/JS-DEV/memory-monitor
./build.sh

Output: build/MemoryMonitor.app

open build/MemoryMonitor.app

Or double-click the app in Finder.

cp -r build/MemoryMonitor.app /Applications/

Then add to Login Items in System Settings → General → Login Items.

• macOS 12.0+ (Monterey or later)
• Apple Silicon (M1/M2/M3) or Intel

memory-monitor/
├── MemoryMonitorApp.swift   # App entry point, menu bar setup
├── MemoryMonitor.swift      # Memory stats + process monitoring
├── MenuBarView.swift        # All UI views (main, detail, pie chart)
├── BridgingHeader.h         # Darwin API imports
├── Info.plist               # App configuration
└── build.sh                 # Build script

• Language: Swift 5.9+ / SwiftUI
• APIs: Darwin (proc_pidinfo, host_statistics64, vm_statistics64)
• Mouse tracking: NSTrackingArea via NSViewRepresentable
• Memory footprint: ~25 MB
• CPU usage: <1%
• No network access — pure local monitoring
• No special permissions — uses standard system APIs

In MemoryMonitor.swift:

• updateInterval — Refresh rate (default: 1.5s)
• processLimit — Default number of processes (default: 8)

In MenuBarView.swift:

• Colors, layout, animations
• Process count options in ProcessCount enum

• CPU usage monitoring
• Network speed monitor
• Disk usage
• Click to force-quit apps
• Memory usage alerts/notifications
• Historical graphs
• Export to CSV

MIT