Privacy Policy

Our Core Privacy Principle

CircadianShield is built on a simple principle: your data stays on your device. We process everything locally. We do not operate servers that receive, store, or analyze your data. Period.

What CircadianShield Accesses

Location (Optional)

CircadianShield requests your approximate location to calculate solar position (sunrise, sunset, solar elevation) for accurate circadian filtering. This data is:

• Processed entirely on your Mac
• Never transmitted to any server
• Used only for solar calculations
• Replaceable with manual city selection if you decline location access

Display Settings

CircadianShield adjusts your display's color temperature and brightness using macOS system APIs (CoreGraphics gamma ramps, Night Shift, accessibility color filters). These changes are applied locally and are fully reversible.

Ambient Light Sensor (Optional, Pro)

If enabled, CircadianShield reads the built-in ambient light sensor via IOKit to adapt screen brightness to room lighting. Sensor data is processed locally and never stored or transmitted.

Activity Detection

CircadianShield monitors keyboard and mouse activity timing (not content) to:

• Detect user inactivity for filter pausing
• Detect flow states for break deferral
• Track screen time duration

This data is processed locally and used only for app functionality. We do not record what you type, what apps you use, or what content you view.

Running Applications

CircadianShield detects the frontmost application's bundle identifier to apply per-app color profiles and smart pause features (e.g., disabling the filter during color-critical apps). We do not record application usage history or transmit this information.

What We Do NOT Collect

• No personal information (name, email, phone number)
• No screen content, recordings, or screenshots
• No browsing history
• No keystroke logging
• No cloud sync of your settings or health data
• No advertising SDKs or cross-app tracking
• No identifiable usage tracking (the optional usage statistics described below are anonymous and can be switched off)

License Validation

CircadianShield validates your license key with our self-hosted licensing server when you activate or periodically re-validate your license. This involves transmitting only your license key and a device identifier, and receiving validation status in return. No other data is shared. The licensing server is operated by Circadian Shield Inc. and does not store personal information beyond what is necessary for license management.

Anonymous Usage Statistics

The app sends optional, anonymous usage statistics to help us understand which features are used and improve the app. These are simple event counts, such as how often a feature is opened. Each event carries only an anonymous device code (a one-way hash used to count unique devices), the app version, and the event name. They contain no screen content, no personal information, and nothing that can be traced back to you. You can switch this off at any time in Settings.

Website Analytics

Our website (circadianshield.com) uses Google Analytics 4 to understand traffic patterns. This is standard, cookie-based web analytics and is completely separate from the CircadianShield application. Within the app, the only data sent is the optional anonymous usage statistics described above, which you can switch off in Settings.

Data Storage

All app data (settings, health scores, break statistics, light debt history) is stored locally on your Mac using macOS UserDefaults and Keychain. This data never leaves your device.

Children's Privacy

CircadianShield does not knowingly collect information from children under 13. The app does not collect personal information from any user.

Changes to This Policy

We will update this page if our privacy practices change. Since the app collects no personal data and sends only optional anonymous usage statistics you can switch off, meaningful changes are unlikely.

Contact

Questions about privacy? Email us at [email protected].