SwiftTempBar

Built with GLM-5.1 (OpenCode) Vibe Coding.

中文文档

A lightweight macOS menu bar temperature monitor for Apple Silicon (M-series chips).

Features

• Real-time CPU / GPU temperature display in the menu bar
• Switchable CPU and GPU mode
• Color-coded temperature display (optional):
  • Blue: < 35°C (Low)
  • Green: 35–45°C (Normal)
  • Orange: 46–55°C (High)
  • Red: ≥ 56°C (Overheating)
• Icon prefix mode (optional) — colored dot ● before temperature for better visibility
• One-click open Activity Monitor
• Configurable refresh interval with presets (1s / 2s / 3s / 5s / 10s / 30s) and fine-tuning (±1s)
• Settings persistence across restarts
• Launch at login option
• English / Chinese menu language switch (defaults to English)
• No Dock icon — lives entirely in the menu bar

Requirements

• macOS 13.0 (Ventura) or later
• Apple Silicon Mac (M1 / M2 / M3 / M4 series)

How It Works

SwiftTempBar reads hardware temperature sensors through macOS private IOKit/HID APIs:

1. IOHIDEventSystemClientCreate — creates a HID system client
2. IOHIDEventSystemClientSetMatching — filters devices by UsagePage=0xFF00, Usage=5 (temperature sensors)
3. IOHIDEventSystemClientCopyServices — enumerates all matching sensor services
4. IOHIDServiceClientCopyProperty — reads each sensor's name ("Product")
5. IOHIDServiceClientCopyEvent — retrieves a temperature event (kIOHIDEventTypeTemperature = 15)
6. IOHIDEventGetFloatValue — extracts the temperature value

Sensors are classified by name prefix:

• CPU: PMU tdie, PMU tdev, pACC MTR Temp, eACC MTR Temp, etc.
• GPU: GPU MTR Temp Sensor, PMU2 tdie, PMU2 tdev, etc.

The private APIs are loaded at runtime via dlopen/dlsym — no bridging headers or ObjC needed.

Project Structure

Sources/
├── StatusBarController.swift   # App entry (@main), menu bar UI, settings
├── TemperatureReader.swift     # HID sensor reading (pure Swift)
├── Assets.xcassets/            # App icon
└── Info.plist

Only 2 Swift source files. No Storyboards, no ObjC, no dependencies.

Building

xcodebuild -project SwiftTempBar.xcodeproj -scheme SwiftTempBar -configuration Release build

Acknowledgements

This project was inspired by and derived from:

• SolitaryJune/TempBarApp (BSD-3)
• Cliffback/macos-temp-tool (BSD-3)
• freedomtan/sensors (BSD-3)

License

See LICENSE.