Ask HN: How to create an online self-hosted anonymous dead-man's switch?

First you need to think about your requirements, for example what do you want to happen if you're dead? Send an email? Post a message to facebook? etc.

Then you need to decide what mechanism you'll use to allow the alive-or-dead test to work.

You might decide you could look at the modification date of ~/.bash_history, and if that is 30+days old send a mail. That would be a simple as setting up a cronjob.

Of course this fails as soon as your machine goes offline. So how do you mitigate against that? You probably need two servers .. and so you go further down the rabbit-hole.

Really your question is vague and you need to consider the mechanism, what you mean by "anonymous", what action should be carried out if you fail, and similar. Then you need to work out the least-complex system that is not likely to fail due to obvious/predictable causes.

I'm not affiliated with these guys: http://pushmon.com/ It's not self-hosted. Other than that, you create some type of a link on their website, and you have to go there every once in a while. You also set up notifications (SMS, email, etc), and if you don't go to their link for some amount of time, they send out alerts.

It's marketed for checking if script ran (script would go to website after it finishes, and lack of that ping results in alarms).

Google has an inactive account manager that feels like a dead-man's switch. But, it's not anonymous https://www.google.com/settings/account/inactive.

Tor hidden service.