NeonFocus

A tiny macOS menu-bar utility that draws a configurable neon halo around whichever selected terminal app window currently has keyboard focus.

┌──────────┐  ┌──────────┐  ┌──────────┐
│ api      │  │ dotfiles │  │ notes    │   ← terminal app windows
│ npm dev  │  │ vim      │  │ tail -f  │
└──────────┘  └━━━━━━━━━━┘  └──────────┘
                  ▲
                  └── pulsing neon halo around the focused one

Status

v0.1.0 — curated terminal-app support with menu-bar controls for app selection, color, thickness, pulse speed, glow intensity, and focus-burst vibration.

Install

brew install --cask pulikkalgokul/tap/neonfocus

That's it — Homebrew downloads the notarized build from the latest release and installs it into /Applications. Launch it from Spotlight or /Applications/NeonFocus.app.

To update later: brew upgrade --cask neonfocus.

Uninstall

brew uninstall --cask neonfocus

To also remove the persisted preferences plist (~/Library/Preferences/com.gokul.NeonFocus.plist):

brew uninstall --cask --zap neonfocus

The Accessibility grant remains in System Settings → Privacy & Security → Accessibility — remove the NeonFocus entry there to revoke it.

Build from source

Prerequisites

• macOS 14+
• Xcode 16+ (the project was generated against Xcode 26.3)
• XcodeGen: brew install xcodegen

Build & run

cd ShowFocus
xcodegen generate
open NeonFocus.xcodeproj
# In Xcode: select the NeonFocus scheme and ⌘R

Or from the command line:

xcodegen generate
xcodebuild -project NeonFocus.xcodeproj -scheme NeonFocus -configuration Debug build
open build/Debug/NeonFocus.app

The Xcode project is not committed; regenerate it with xcodegen generate any time you change project.yml.

Run the unit tests with:

xcodebuild -project NeonFocus.xcodeproj -scheme NeonFocus -destination "platform=macOS,arch=$(uname -m)" test

Cutting a release

The release pipeline (Developer ID signing → Apple notarization → stapling → GitHub release → cask bump in the tap repo) is run from a maintainer's machine and is not part of the public source tree. See scripts/ExportOptions.plist for the export config used.

First-run permission

NeonFocus needs Accessibility permission to read the focused terminal window's frame. On first launch, macOS will prompt you. If you miss it:

System Settings → Privacy & Security → Accessibility → enable NeonFocus

No screen-recording or input-monitoring permissions are required.

What it does

• Lives in the menu bar as a circle.dashed icon.
• Provides an enable toggle, terminal-app selection, overlay style submenus, and Quit NeonFocus.
• When a selected terminal app is frontmost, it watches focus changes via the Accessibility API (kAXFocusedWindowChangedNotification, kAXMovedNotification, kAXResizedNotification).
• A transparent click-through NSPanel follows the focused window's frame and renders a Core Animation neon pulse with an outer edge-fade glow.
• Plays a short focus-burst vibration when focus moves to a different terminal window.
• Persists the enable state, selected terminal apps, and overlay settings in UserDefaults.
• When you ⌘-Tab to anything other than a selected terminal app, the overlay hides.

Menu settings

• Color: Hot Pink, Electric Cyan, Acid Green
• Thickness: Slim, Regular, Bold
• Pulse Speed: Slow, Normal, Fast
• Glow: Subtle, Bright, Vivid
• Vibration: Focus Burst, Off
• Terminal Apps: Apple Terminal, iTerm2, Ghostty, Warp, Warp Preview, WezTerm, kitty, Alacritty

Architecture (one screen)

NeonFocusApp ──► AppDelegate ──► FocusCoordinator ──┬── ActiveAppMonitor ──► NSWorkspace
                                                    ├── AccessibilityPermissions
                                                    ├── AXFocusTracker ──► AXObserver
                                                    ├── NeonFocusSettingsStore ──► UserDefaults
                                                    ├── OverlayController ──► OverlayPanel
                                                    │                         └── NeonPulseView ──► NeonPulseAnimationSpec
                                                    └── StatusMenuController ──► NSStatusItem

Known limitations

• Curated terminal apps only. Arbitrary app selection is intentionally not exposed; new terminal apps should be added to the curated list after AX behavior validation.

License

MIT