🪤 Dead Man's Switch

A heartbeat watchdog that fires when you go silent.

"If I don't check in by tomorrow, the package ships itself."

What is it?

The Dead Man's Switch is the oldest trick in the espionage playbook, turned into a tiny command-line tool. You arm it with a TTL (time-to-live). You stamp a heartbeat file — a proof of life. If the heartbeat goes stale — if you're taken, you're cut off, or your cron just breaks — the switch fires its payload.

A natural fit for:

• Novel research — the scene where the captured hero can't touch the file and the countdown is real.
• Automation safety — if a scheduled task stops reporting, get an alert.
• Personal failsafes — a check-in ritual that escalates when it breaks.

Features

• ⏱️ Heartbeat file with configurable TTL
• 🔫 Four payload types: print, webhook, email, command
• 🌀 Watch mode — blocks and fires the moment the switch trips
• 🛡️ status command tells you exactly how much slack you have left
• 📦 Zero runtime dependencies, pure Python standard library

Install

pip install deadman-switch

From source:

git clone https://github.com/AnonymoDGH/deadman-switch
cd deadman-switch
pip install -e .

Quickstart

# 1. Arm it — 60 seconds of silence means fire
dms arm --ttl 60 --payload '{"type": "command", "command": "echo released the files"}'

# 2. Prove you're alive
dms heartbeat

# 3. How much slack is left?
dms status
# [+] Alive. Last beat 3s ago, 57s of slack left.

# 4. Block until the switch fires
dms watch

CLI reference

All commands accept --config <path> to point at a different config file.

Payloads

{ "type": "webhook", "url": "https://example.com/hook", "data": "{\"op\":\"release\"}" }
{ "type": "email", "from": "agent@example.com", "to": "control@example.com",
  "subject": "SILENCE", "message": "The package is loose.",
  "smtp_host": "smtp.example.com", "smtp_user": "u", "smtp_pass": "p" }
{ "type": "command", "command": "python notify.py --urgent" }

How it works

Tests

pip install pytest
pytest

License

MIT — a fiction research prop. Use it on systems you own, and keep the fireworks in the novel where they belong.