# Vision Test Webhooks

Webhooks enable real time processing of vision test status updates. Webhooks are available via email and HTTP channels.

## Subscribing to Webhooks

To subscribe to webook notifications use [createNotificationSubscription](/reference/visibly-api/mutations/createNotificationSubscription) and [deleteNotificationSubscription](/reference/visibly-api/mutations/deleteNotificationSubscription) to unsubscribe.

## Webhook payload format

To maintain consistency, webhook payloads use the same format as the GraqhQL `visionTestJob` query response. [(See visionTestJob reference here.)](/reference/visibly-api/queries/visionTestJob)

In order to identify webhooks pertient to a vision test, key off of the `eventType` field in the payload response body. Any vision tests started with the `startVisionTest` mutation will automatically trigger webhook notifications for status updates. To the will return `VISION_TEST_JOB_UPDATED` as the value of `eventType` property in webhook payloads.

To enable you to determine the status of a given vision test, each webhook payload will additionally contain a `status` and `reason` fields. ([See "Vision Test Statuses"](/developer-guides/vision-testing/vision-test-statuses))

## Webhook Durability

In the event a webhook subscriber fails to process a webhook successfully, Visibly will retry it several times for ~24 hours.

Important: for maximum durability, it is recommended to use webhooks in conjunction with a polling mechanism that uses the `visionTestJob` to monitor statuses just in case webhooks were not processed successfully.