This endpoint synchronously sends a liveness probe to the selected alert receiver. The response message describes the outcome of the probe: either the successful response (as appropriate), or indication of why the probe failed.

The result of the probe is represented as an AlertDelivery model. Details relating to the status of the probe depend on the alert delivery mechanism, and are included in the AlertDeliveryAttempts model. For example, webhook receiver liveness probes include the HTTP status code returned by the receiver endpoint.

Note that the response status is 200 OK as long as a probe request was able to be sent to the receiver endpoint. If an HTTP-based receiver, such as a webhook, responds to the another status code, including an error, this will be indicated by the response body, not the status of the response.

The resend query parameter can be used to request re-delivery of failed events if the liveness probe succeeds. If it is set to true and the liveness probe succeeds, any alerts for which delivery to this receiver has failed will be queued for re-delivery.