"Dead man's switch" - Can I get alerts if my server stops pinging Wormly?

Yes - this can be achieved with the Wormly Metrics service.

Once you've added a host, click on the Metrics tab. You'll see some info explaining how to inject metrics into the system; whether by installing an agent or just periodically POSTing a metric to our HTTP endpoint.

Whichever option you choose, once metrics are being submitted you can create an alert rule to notify you when the "time since last metric seen" exceeds the threshold you define.

This will function as a sort of "Dead Man's Switch", where alerts are triggered if your host is no longer pinging Wormly - rather than the other way around. Handy for internal systems which do not expose any public API interface.