Effective April 25, 2026

Sentinel Privacy Policy

Sentinel is a macOS network monitor and filtering app by Guangyu Song. It is designed to help you understand which apps on your Mac connect to the internet.

Data Sentinel Processes

Sentinel may process local network connection information on your Mac, including app or process identity, destination hostname or IP address, port, protocol, direction, interface, rule decision, timestamps, and byte counts.

Where Data Is Stored

Connection history, rules, and app settings are stored locally on your Mac. Sentinel uses the app group container where available and may use local Application Support storage as a fallback.

Data Sentinel Does Not Collect

The Sentinel app does not include advertising SDKs, tracking SDKs, analytics SDKs, or automatic crash-report uploads. The app does not sell personal data.

Destination Geolocation

Sentinel uses a bundled GeoIP database where available to estimate destination locations for the map. Sentinel does not silently send destination IP addresses to third-party geolocation web services.

Location Permission

Sentinel may ask macOS for your approximate current location to center the map near your Mac. If you do not grant location permission, Sentinel uses a coarse local fallback.

Network Extension Permission

Sentinel uses Apple's Network Extension system to monitor and filter network connections after you approve it in macOS. You can disable the filter from the app or macOS settings.

Retention And Deletion

Sentinel supports live-only history and limited local retention windows. You can delete local connection history from inside the app.

Website Analytics

This Sentinel privacy page is served without the site's analytics script.

Contact

For privacy questions, contact sentinel@guangyusong.com.