What is the “caliber-health/1” request hitting my app?

If you watch your app's access logs, you may notice a request from our management panel (IP 152.53.210.109) hitting your app once every 5 minutes. You can spot it by its user agent:

User-Agent: caliber-health/1

This is our uptime health check, and it is completely expected.

What it does

• Sends a single GET / to your app every 5 minutes.
• Reads only the HTTP status code to confirm your app is responding. Anything under 500 counts as "up" — so a login page, a redirect, or a 401 all count as healthy.
• Never logs in, submits data, or changes anything. It is read-only.

If your app stops responding for about 10 minutes straight, we email you an "app unreachable" notice, and a "recovered" note when it comes back.

Does it restart my app?

No. The health check never restarts, rebuilds, or suspends your app. Its only job is to notice when something is down and let you know. The only thing that restarts your app is you, from the app's power controls.

Does it interfere with my Access restrictions?

No. If you use the Access tab to limit your app to specific IP addresses, the health check is unaffected — it runs on a separate internal path and keeps working, so your restrictions will not cause false "down" alerts. You do not need to add our IP to your allowlist; it is not part of that list.

Can I ignore it?

Yes — it is a normal part of running a managed app with us and is safe to ignore. If you filter your own logs, you can exclude the caliber-health/1 user agent.