# Add liveness checks to your Daemons

By Steven Van · 2026-10-30

Daemons in Public Beta on all plans can now point a livenessProbe at an HTTP endpoint, and Vercel restarts the container when it fails.

Vercel Daemons now accept an HTTP liveness check, so a worker that is still running but no longer healthy gets restarted. [Vercel](<https://creatorstoolbox.com/tools/vercel>) describes the change in its [Daemons documentation](<https://vercel.com/docs/daemons>).

## How the check works

The daemon serves a lightweight HTTP endpoint that returns an error status when the worker is unhealthy. In Vercel's example, a flag flips to false on a connection error and the endpoint then returns 500 instead of 200. The daemon configuration points at that endpoint with a livenessProbe value, using httpGet with a port and path, for example port 1234 and path /health.

Vercel sends an HTTP GET request to each instance on a schedule. A status from 200 to 399 counts as a success, and redirects are not followed. A connection error, a timeout or any other status counts as a failure. After enough consecutive failures (the failureThreshold), Vercel restarts the container.

## Restart behaviour

- Liveness restarts send SIGKILL immediately and do not honor terminationGracePeriodSeconds.

- Restarts use exponential backoff, starting at 1 second and doubling up to 5 minutes. A run of at least 5 minutes resets the backoff.

- After 10 minutes of runs that each last under 5 minutes, Vercel stops restarting the instance and replaces it with a new one.

## Configuration notes

The documentation lists optional tuning fields, including initialDelaySeconds, periodSeconds and timeoutSeconds. Defaults are a 10-second period, a 1-second timeout and a failure threshold of 3. A changed livenessProbe applies only to instances started after it deploys. A worker that does not already run an HTTP server needs to add one, or every check will fail and the instance will restart repeatedly.

Daemons are in Public Beta on all plans.

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Sources

[Original source](<https://vercel.com/changelog/add-liveness-checks-to-your-daemons>)

[Read Add liveness checks to your Daemons on Creators Toolbox](<https://creatorstoolbox.com/blog/vercel-add-liveness-checks-to-your-daemons>)

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Canonical source: https://creatorstoolbox.com/blog/vercel-add-liveness-checks-to-your-daemons