Catlock

A macOS menu bar utility that blocks all keyboard and mouse input—perfect for when your cat decides to take a nap on your keyboard.

Download

Download Catlock v1.0.0

Features

• Complete input blocking: Blocks keyboard, mouse, trackpad, and scroll wheel
• Menu bar only: No dock icon, minimal footprint
• Safe toggle hotkey: Escape + Delete (hard for cats to press)
• Emergency unlock: Fn + Escape always unlocks, no matter what
• Auto-timeout: Automatically unlocks after 10 minutes (safety feature)
• Failsafe: Always starts unlocked, even after crashes

Installation

1. Download and unzip Catlock.zip from the latest release
2. Move Catlock.app to Applications
3. Launch and grant Accessibility permission when prompted
4. Restart the app after granting permission

Note: The app is signed and notarized by Apple, so it should open without any Gatekeeper warnings.

Permissions

Catlock requires Accessibility permission to intercept input events.

On first launch:

1. You'll see a permission prompt
2. Go to System Settings → Privacy & Security → Accessibility
3. Enable Catlock in the list
4. Restart the app

Why Accessibility? CGEventTap requires this permission to intercept events from other applications. Without it, the app cannot block input.

Usage

Hotkeys

Action	Hotkey
Toggle lock	Escape + Delete
Emergency unlock	Fn + Escape (always works)

Menu Bar

Click the cat icon in the menu bar to enable/disable Catlock.

Visual Indicators (SF Symbols)

• Cat outline = Unlocked (normal operation)
• Filled cat = Locked (input blocked)

Testing Safely

1. Launch the app (you'll see a cat icon in the menu bar)
2. Open a text editor
3. Press Escape + Delete to enable Catlock
4. Try typing—nothing should happen
5. Press Escape + Delete again to disable
6. Verify typing works again

Tip: If anything goes wrong, Fn + Escape will always unlock.

Requirements

• macOS 13 Ventura or later
• Accessibility permission

Building from Source

1. Open Catlock/Catlock.xcodeproj in Xcode
2. Select your development team in Signing & Capabilities
3. Build and run (⌘R)

Technical Details

Event Types Blocked

• Keyboard: keyDown, keyUp, flagsChanged
• Mouse: mouseMoved, all click events, drag events
• Scroll: scrollWheel

Architecture

• EventTapManager.swift: CGEventTap handling, hotkey detection
• AppDelegate.swift: Menu bar UI, app lifecycle
• Info.plist: LSUIElement (menu bar only), accessibility description
• main.swift: App entry point with MainActor isolation

Security Notes

• Signed and notarized by Apple
• App Sandbox is disabled (required for CGEventTap)
• Hardened Runtime is enabled
• No private APIs used
• Distributed outside Mac App Store

Troubleshooting

"Failed to create event tap"

• Ensure Accessibility permission is granted
• Restart the app after granting permission
• Check System Settings → Privacy & Security → Accessibility

Hotkey not working

• Use the failsafe: Fn + Escape
• Check if another app is capturing these keys
• Relaunch the app

Stuck in locked state

1. Press Fn + Escape (always works)
2. Wait 10 minutes (auto-timeout)
3. If all else fails: hold power button to restart

License

MIT