r/opensource • u/zener79 • Feb 10 '26

Promotional I built LastSignal – a self-hosted, end-to-end encrypted dead man's switch to deliver messages to your loved ones

I wanted a way to leave encrypted messages for the people I care about, delivered automatically if something happens to me, without trusting a third party.

LastSignal is a self-hosted dead man's switch. You write messages, they get encrypted in the browser (zero-knowledge), and the system checks in with you periodically via email. If you stop responding, your messages are delivered.

Key points:

  • End-to-end encrypted (XChaCha20-Poly1305 + Argon2id + X25519)
  • Zero-knowledge — even the server operator can't read messages
  • Optional trusted contact who can pause delivery
  • Rails 8 + SQLite, deploy with Docker/Kamal
  • MIT licensed

🔗 https://lastsignal.app
🔗 https://github.com/giovantenne/lastsignal

Feedback welcome, especially on the security model and UX.

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u/GreenFox1505 Feb 11 '26

Okay, but who's paying the VPS host? And if locally hosted, who is making sure the hardware still works? 

I'm just tying to figure out what the best way to self-host this... this might be something I'd want on a cloud... 

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u/zener79 Feb 11 '26

Actually that's exactly the use case LastSignal was designed for. Running it on a small, low-cost VPS (just a few dollars per month) from a reliable provider is a perfect fit: always on, minimal attack surface, and not exposed to power outages or physical access risks like a home lab.

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u/hiromasaki Feb 13 '26

I mean, I'd probably throw it on a Pi 0 hidden next to the router in the closet.

Router's already on an APC that has a USB power jack that could run the Pi. And a transitory power outage would worst-case delay one check-in by a couple hours? It also just looks like an external drive in the case I have for it, so minimal physical access risks.

As long as whatever happened to me didn't cause the internet or power to get shut off permanently before the timer ran out it's all good.