Does it keep ringing until I answer?
Yes. A critical alert repeats every 30 seconds for up to 60 minutes, or until you tap Acknowledge. On Android it takes over the whole screen at alarm volume. On iOS it arrives as a Time-Sensitive notification.
Frequently asked questions
Questions and Answers
Is it self-hosted?
Yes. One Docker command, one SQLite file, no other database. Run it on a VPS, a Raspberry Pi, or your homelab under AGPL-3.0, and point the official app at your server URL.
Does it work with Uptime Kuma / ntfy / Healthchecks / Home Assistant?
Yes. Crit Alarm works with Uptime Kuma, Healthchecks, Home Assistant, and anything that speaks ntfy. It implements the ntfy publish endpoints (POST /{topic}) and header aliases (X-Priority, X-Title, X-Tags). Point an existing ntfy webhook at a Crit Alarm topic and the payload does not change.
What does the relay see?
The relay sees a hash of your topic name, the incident id, and the device push token it has to poke. It never sees your alert titles, your message bodies, your topic names, or your server hostname. Your phone fetches those from your own server.
How much does it cost?
Self-hosting is free. The Free tier gives you 5 topics. Pro is a flat $4 a month for the whole account, with no per-seat and no per-alert charge.
What does iOS do today?
Priority 5 arrives as a Time-Sensitive notification and the repeat loop still runs every 30 seconds. Android takes the whole screen at alarm volume.
Have more questions?
Read the API docs, look at the server on GitHub, or email.