# message_reads Webhook Event Reference
This event will be sent to your webhook when a message a Page has sent has been read by the user.
You can subscribe to this callback by selecting the `message_reads` field when [setting up](https://developers.facebook.com/documentation/business-messaging/messenger-platform/webhooks#setup) your webhook.
## Example {#example}
```
{
"sender":{
"id":"<PSID>"
},
"recipient":{
"id":"<PAGE_ID>"
},
"timestamp":1458668856463,
"read":{
"watermark":1458668856253
}
}
```
## Properties {#properties}
### `sender`
| `sender` Field | Description |
| --- | --- |
| `id` *string* | The Page-scoped ID for the person who sent a message to your business |
### `recipient`
| `recipient` Field | Description |
| --- | --- |
| `id` *string* | The ID for your Facebook Page |
### `read` {#read}
| Property | Type | Description |
| --- | --- | --- |
| `watermark ` | Number | All messages that were sent before or at this timestamp were read |
The `watermark` field is used to determine which messages were read. It represents a timestamp indicating that all messages with a timestamp before `watermark` were read by the recipient.