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

# Alert Channel Overview

> Learn how to configure alert channels with the Checkly CLI.

Alert channels let you get alert notifications when a check or monitor fails. [Learn more about alerting in our docs](/communicate/alerts/overview/).

## Common properties

All alert channels share a set of common properties to define when / how they should alert derived from the abstract class
`AlertChannel`.

Configure common alert channel properties:

| Property             | Type      | Required | Default | Description                                   |
| -------------------- | --------- | -------- | ------- | --------------------------------------------- |
| `sendRecovery`       | `boolean` | ❌        | `true`  | Send notifications when checks recover        |
| `sendFailure`        | `boolean` | ❌        | `true`  | Send notifications when checks fail           |
| `sendDegraded`       | `boolean` | ❌        | `false` | Send notifications when checks degrade        |
| `sslExpiry`          | `boolean` | ❌        | `false` | Send notifications for SSL certificate expiry |
| `sslExpiryThreshold` | `number`  | ❌        | `30`    | Days before SSL expiry to send notification   |

Alert channels are assigned to checks, monitors, and groups by instantiating a class and adding the resulting object to the
`alertChannels` array:

```ts api-health.check.ts theme={null}
import { ApiCheck, EmailAlertChannel } from 'checkly/constructs'

// Create a new alert channel
const emailChannel = new EmailAlertChannel('email-channel-1', {
  address: 'alerts@example.com',
})

// Create a new API check
new ApiCheck('api-health-check', {
  name: 'API Health',
  request: {
    method: 'GET',
    url: 'https://api.example.com',
  },
  alertChannels: [emailChannel], // Assign our email alert channel to this API check
})
```

To assign alert channels to `CheckGroupV2` constructs, you'll also need to set the [`alertEscalationPolicy`](/constructs/check-group-v2#param-alert-escalation-policy) to enable the group alerting override.

## Using `fromId()` to reference an existing channel

If you have an existing alert channel that was created outside of your CLI project, you can reference it using the `fromId()` method on any `AlertChannel` class:

```ts theme={null}
export const emailChannel = EmailAlertChannel.fromId(20)
```

Find the alert channel ID in the the [Checkly web UI](https://app.checklyhq.com/accounts/alerts/settings) or via our our [REST API](/api-reference/alert-channels/list-all-alert-channels/).

<img src="https://mintcdn.com/checkly-422f444a/YgQcQD6j5p9gqjr5/images/docs/images/cli/constructs_email_id@2x.jpg?fit=max&auto=format&n=YgQcQD6j5p9gqjr5&q=85&s=ff0f1592af406256699a7e6a9fd60855" alt="email channel id" width="1290" height="570" data-path="images/docs/images/cli/constructs_email_id@2x.jpg" />

<Note>
  If your `fromId()` references an invalid alert channel, the CLI will throw an error when you try to deploy your project.
</Note>

This is useful if you have multiple CLI projects, since you can reference the same alert channel in each project without needing to redefine it each time.

If you have a single CLI project, instead of using `fromId()`, we recommend defining your alert channel within that CLI project and referencing its JS/TS object. This allows your alert channel to be managed as code alongside your other CLI resources, which makes it easier to manage and scale your alerting setup.