A private network firewall for Mac
See what your Mac is talking to.
Understand every app connection. Block what should not leave your Mac. Keep the history and rules local.
Quiet by default
Built for attention, not anxiety.
Sentinel opens on a live map and groups connections by app, so the first thing you see is behavior—not a wall of process names.
Monitor quietly, ask about unknown connections, or block them until you decide.
Understand. Decide. Move on.
A firewall should explain itself.
- 01 See the connection
Sentinel groups live activity by app and destination, with approximate locations on the map.
- 02 Understand the decision
Inspect why traffic was allowed, blocked, or needs you to choose.
- 03 Set a local rule
Allow once, allow for a while, or create a lasting rule without sending your traffic history anywhere.
Local-first privacy
Your connection history belongs on your Mac.
The app does not include advertising SDKs, analytics SDKs, or automatic crash-report uploads.
Destination geolocation uses a bundled GeoIP database where available.
Connection history can be live-only or retained locally for a limited period.
Sentinel downloads a list only when you add, change, or refresh its HTTPS subscription.
Sentinel for macOS
Your Mac can tell you where it is talking.
Get Sentinel on the Mac App Store, read the privacy policy, or contact sentinel@guangyusong.com.