I prefer the service known as “your family and friends”.

I seriously thought there was a service with this name (like deadmansswitch) and searched online for it. Then it hit me, and I got what you meant! I agree that’s the best way to handle it.

There is one. It's called deadmanssnitch.com

Just a scheduled post that you postpone while you're alive.

No, the proper way to do it is to include the curl request to be run as part of your last will and testament.

Event-driven architecture.

This feels like a very risky choice that a technical error or other interruption announces your death prematurely.

I would probably just ensure at least one or two trusted people have the access to post it on your behalf and know it is very important to you that it gets done.

Yeah, you could lose control of some account and that would be pretty awkward if your Goodbye Farewell just plopped out when you went in to extend it another week but found out you’re sitting on a support ticket.

Or worse; I dunno get hit by a bus and be in the hospital, or perhaps arrested? Friends and family don’t know what happened to you and then your death announcement blares.

I think only people expecting their death to be likely in the next year should want to employ this however, and that probably changes things.

Solutions I've seen before allow you to set a backup person that gets contacted. So, like, maybe there's a weekly email you have to reply to. If you don't respond in a day, it texts you instead. After a set period of time it will reach out to your trusted contact who can confirm whether you're okay or not.

You could do the warnings aka similar to domain expiry. Lots of follow ups etc.

I like the curl on will option (or for a lawyer maybe email with link)

It's not an answer to this, but tangentially related as we had a similar conversation at work very recently. Not many people know about Google and Apple's inactive account manager setup (https://support.google.com/accounts/answer/3036546?hl=en). If you've not already done this I'd highly recommend adding your spouse/kin/best mate etc as a contact. I set this up to transfer over access to my Google Drive to my wife if I've been inactive for some period. We have separate offline docs around keys and access, but if the worst happened, then eventually she'll get a message with instructions on decrypting and accessing the critical info she needs. A lot of my (tech savvy) co-workers had no idea this was a thing.

If you can trust Github enough, then Github Workflow that runs a schedule build everyday should be able to do it. Have a future date post (built-in with Github Pages), say, a month ahead of now. Every now and then, you as long as you are alive, increase the month.

I wrote something that does this (amongst other things) ages ago when I was learning Go. https://github.com/intermernet/watchdog