Therma

RAM & CPU temperature monitor for macOS. Lives in your menu bar. Zero bloat.

Download · Features · Build from Source · Auto-Update · Contributing

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Therma gives you a permanent, low-overhead view of your Mac's memory and thermals — right in the menu bar. No subscription, no analytics, no Electron, no bloat.

Memory  63%  ·  CPU  54°C

That's it. One line. Always there.

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Features

Menu Bar

• Live RAM usage % and/or CPU temperature in the status bar
• Adjustable icon size, text size, and display mode (RAM · CPU · Both)
• 35 built-in color themes — Amber, Arctic, Cosmic, Matrix, Lava, and more

Memory

• Used / free / wired / compressed breakdown
• Memory pressure ring with gradient stroke
• One-click RAM purge — sends memory pressure signal to encourage apps to release caches
• Deep Clean — clears Xcode DerivedData, Gradle, JetBrains caches + purge

CPU Temperature

• Real-time per-sensor readings via IOKit / SMC (Apple Silicon & Intel)
• Color-coded thermal zones: 🔵 cool → 🟢 normal → 🟡 warm → 🟠 hot → 🔴 critical
• Historical bar chart (last 20 readings)

Alerts

• Local notifications when RAM or CPU crosses your custom threshold
• 5-minute cooldown to prevent notification spam

General

• Launch at Login via ServiceManagement
• Temperature unit: °C or °F
• In-app updates via GitHub Releases — one click, no appcast server needed

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Requirements

macOS	14.0 Sonoma or later
Architecture	Apple Silicon (arm64)
Build tools	Xcode Command Line Tools (for source builds)

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Installation

Download (recommended)

1. Go to Releases
2. Download Therma-<version>.zip
3. Unzip → drag Therma.app to /Applications
4. Open Therma and grant the accessibility permission if prompted

Homebrew (coming soon)

brew install --cask therma

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Build from Source

# Clone
git clone https://github.com/jayzzjay98-stack/Therma.git
cd Therma

# Build, bundle, and install to /Applications
bash install.sh

The install.sh script:

1. Compiles a release binary via Swift Package Manager
2. Assembles the .app bundle with Info.plist and AppIcon.icns
3. Copies the bundle to /Applications/Therma.app
4. Registers a Login Item and launches the app

Run tests:

swift test
# → 65 tests, 0 failures

Regenerate the app icon:

bash scripts/build_icon.sh
# Draws a 1024×1024 PNG with NSBezierPath → sips → iconutil → AppIcon.icns

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Auto-Update

Therma updates itself from GitHub Releases with no external server needed.

For users: Settings → About → Check for Updates → Download → Install & Relaunch

For maintainers — publishing a release:

# 1. Bump CFBundleShortVersionString in Info.plist (e.g. "1.1")
# 2. Build and verify a clean release zip
bash scripts/build_release_zip.sh

# 3. Create a GitHub Release tagged vX.Y.Z and attach the zip from dist/
gh release create v1.1 dist/Therma-1.1.zip \
  --title "Therma 1.1" \
  --notes "What changed."

The release script creates a zip named Therma-<version>.zip, keeps Therma.app at the archive root, strips update-breaking metadata, applies ad-hoc signing, and runs the updater dry-run verifier before you upload the asset.

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Project Structure

Therma/
├── Sources/Therma/
│   │
│   ├── ThermaApp.swift              # @main — app entry point
│   ├── AppContext.swift             # Shared singletons (monitors, prefs, updater)
│   ├── StatusBarController.swift   # Menu bar item, popover, right-click menu
│   │
│   ├── RAMMonitor.swift             # Memory stats via Mach host_statistics64
│   ├── CPUMonitor.swift             # Temperatures via IOKit / SMC
│   ├── CPUSensorPolicy.swift        # Sensor ranking & selection
│   ├── MemoryStatsProvider.swift    # vm_statistics64 abstraction
│   │
│   ├── MenuBarView.swift            # SwiftUI popover root
│   ├── MenuBarComponents.swift      # CPU cards, stat boxes, history bars
│   ├── MenuBarLabel.swift           # Status bar text rendering
│   │
│   ├── SettingsView.swift           # Settings window (sidebar layout)
│   ├── SettingsViewComponents.swift # Sidebar items, pref rows, sliders
│   ├── MenuBarPreferences.swift     # All preferences (UserDefaults-backed)
│   ├── LayoutMetrics.swift          # Window & layout constants
│   ├── ThemeRegistry.swift          # 35 built-in color themes
│   │
│   ├── UpdateManager.swift          # GitHub Releases auto-updater
│   ├── AlertManager.swift           # UNUserNotificationCenter alerts
│   ├── PurgeManager.swift           # Privileged RAM purge
│   ├── CacheManager.swift           # Developer cache sweep
│   │
│   ├── ProcessManager.swift         # Top-process listing
│   ├── ProcessCore.swift
│   ├── ProcessProtectionPolicy.swift
│   ├── ProcessSnapshotReader.swift
│   ├── LeftoverProcessDetector.swift
│   ├── AppLifecycleTracker.swift
│   │
│   ├── ChipDetector.swift
│   ├── LaunchAtLoginManager.swift
│   ├── MonitorDisplayMode.swift
│   └── Constants.swift
│
├── Tests/ThermaTests/               # 65 unit tests
│
├── scripts/
│   ├── generate_app_icon.swift      # Programmatic icon (NSBezierPath)
│   └── build_icon.sh                # PNG → iconset → .icns
│
├── .github/workflows/ci.yml         # Build + test on every push / PR
│
├── install.sh                        # Build + install to /Applications
├── uninstall.sh                      # Remove app, sudoers rule, login item
├── create_dmg.sh                     # Package a release DMG
├── notarize.sh                       # Apple notarization workflow
├── Info.plist
├── Package.swift
└── AppIcon.icns

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Permissions

Permission	Reason
Accessibility	Reading CPU temperature sensors via IOKit
Notifications	RAM / CPU threshold alerts
Login Items	Launch at login (off by default)

Therma makes no network requests except when you explicitly click Check for Updates.

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CI

Every push and pull request to main runs the full test suite via GitHub Actions (.github/workflows/ci.yml):

• Debug build + 65 unit tests
• Release binary (arm64) on main pushes
• DMG artifact uploaded to workflow artifacts

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Contributing

1. Fork the repo and create a branch: git checkout -b feature/my-change
2. Make your changes
3. Run swift test — all 65 tests must pass
4. Commit with a Conventional Commit message
5. Open a pull request

Bug reports and feature ideas are welcome via Issues.

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License

MIT © 2025 jayzzjay98-stack