> ## Documentation Index
> Fetch the complete documentation index at: https://antideploy.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Health Checks and Downtime Email

> Antideploy checks every deployed app every few minutes and emails you when one goes down or recovers.

Antideploy watches whether your app is up. It does not collect metrics, and
there is no metrics dashboard; knowing that is more useful than discovering it
during an incident.

## What is checked

Every few minutes, Antideploy sweeps every application that has a live
deployment and records one of four states.

| State        | What it means                                                                                  |
| ------------ | ---------------------------------------------------------------------------------------------- |
| **Healthy**  | The service is ready and not returning an unusual number of errors.                            |
| **Degraded** | The service is running, but three or more requests returned a 5xx in the last fifteen minutes. |
| **Down**     | The service is not ready: it failed to start, or the revision is broken.                       |
| **Unknown**  | We could not reach the platform to ask.                                                        |

The state appears on your application in the dashboard. Without this check the
dashboard would report whatever was true at deploy time: an app that died an
hour ago would still show a green badge, which is worse than showing nothing.

<Note>
  A single bad reading is not an outage. An app must fail two consecutive checks
  before it is reported as down, so a momentary blip in the underlying platform
  does not page you.
</Note>

## Email notifications

You are emailed when an application **changes state**: when it goes down, and
again when it recovers. You are not emailed on every check, and there is no
digest.

Deploy failures are emailed separately, with the build log, at the moment the
deploy fails.

## What is not collected

<Warning>
  Antideploy does not collect or display request rate, latency, error
  percentages, CPU, memory, or database connection counts. There is no metrics
  tab, no charts, and no alert rules to configure.

  If you need application metrics, instrument your app and send them to a
  service you control; the credentials go in your environment variables like
  any other.
</Warning>

The one signal Antideploy does derive from traffic is the 5xx count behind the
**Degraded** state above, and it is not exposed as a metric you can query.

<Card title="Logs" icon="file-lines" href="/docs/operations/logs">
  Reading what your application actually printed.
</Card>