What it is, and what it isn’t
What it can do, and does:- give an honest, live view of each agent’s resource use and activity
- flag anomalies early rather than after the fact
- estimate spend from local logs
- hand you a reliable kill switch
Why it exists
Desktop AI agents run as ordinary processes on your machine, spawning children, opening sockets, and burning tokens — with almost no visibility into any of it. Activity Monitor shows CPU, but cannot tell you which agent, or what it is costing, or whether this is normal for that agent. Agent Sentinel answers those three questions in one place, and puts a stop button next to the answer.What you get
Honest limitations
Worth knowing before you rely on it:- Token costs are best-effort estimates, derived from local logs and public per-model pricing. They will not match your provider invoice exactly, and the pricing table is maintained by hand.
- Throttle is effectively one-way in the default build. Lowering CPU priority is unprivileged; raising it back is not.
- The kill switch only reaches your own processes. Anything owned by another user or by the system returns
notPermitted. - Deep file and network telemetry is not in the default build. That needs an Endpoint Security system extension and an Apple-granted entitlement.
Preview without building
An interactive mock-up of the menu-bar popover — live metrics, threshold-driven status, and a working Stop / Stop All / Pause — ships as a single self-contained HTML file atdocs/interface-preview.html in the repository. Open it in any browser to see the interface without building anything.
It reproduces the layout and behaviour, and mirrors the same anomaly thresholds the Swift core uses. The shipping app is native SwiftUI.
Next
Install and build
Requirements, building the app, permissions, and distribution.
Headless CLI
Snapshot, watch, and kill agents from the command line or a script.