LastSignal

A self-hosted dead man's switch that delivers end-to-end encrypted messages to chosen recipients when the user stops responding to periodic email check-ins. It targets individuals and families who want to ensure their final messages reach loved ones, as well as IT and security teams seeking a privacy-focused solution. The service is open source, self-hosted, and zero-knowledge, with client-side encryption and public-key cryptography, ensuring the server cannot read the messages.

Key features

• Client-side encryption
• Zero-knowledge server
• Public-key cryptography
• Passwordless login via magic link
• Flexible check-in schedule
• Emergency stop with recovery code
• Complete audit trail
• Docker ready deployment