# Facebook Messenger channel properties

There are Facebook Messenger channel-specific properties that can be used when making calls to the Conversation API. These properties can be listed under `channel_properties` in the message request.

For example, below is the code for adding the channel specific property `MESSENGER_NOTIFICATION_TYPE` to a Conversation API call:


```json
{
  "app_id": "{{APP_ID}}",
  "recipient": {
    "contact_id": "{{CONTACT_ID}}"
  },
  "message": {
    "text_message": {
      "text": "Text message from Sinch Conversation API."
    }
  },
  "channel_priority_order": ["MESSENGER"],
  "channel_properties": {
    "MESSENGER_NOTIFICATION_TYPE": "SILENT_PUSH"
  }
}
```

The relevant Facebook Messenger channel properties are detailed in the table below:

| Property name | Property value |
|  --- | --- |
| `MESSENGER_MESSAGING_TYPE` | Messenger messaging type. For more information visit: [https://developers.facebook.com/docs/messenger-platform/send-messages/#messaging_types](https://developers.facebook.com/docs/messenger-platform/send-messages/#messaging_types) Defaults to `MESSAGE_TAG` if `MESSENGER_MESSAGE_TAG` is set. |
| `MESSENGER_MESSAGE_TAG` | Messenger message tag. Enables sending specific updates to users outside the standard messaging window. If you want to send messages after the 24h response window, you must include the proper message tag. For more information, including a list of possible values and applicable policies, visit: [https://developers.facebook.com/docs/messenger-platform/send-messages/message-tags](https://developers.facebook.com/docs/messenger-platform/send-messages/message-tags) There is no default value for this property. |
| `MESSENGER_NOTIFICATION_TYPE` | Messenger push notification type. Possible values are `REGULAR` (sound/vibration), `SILENT_PUSH` (on-screen notification only) and `NO_PUSH` (no notification). The default is `REGULAR`. |
| `MESSENGER_NOTIFICATION_MESSAGES_TOKEN` | Messenger marketing messages token. You can pass the token to send Marketing Messages outside the standard messaging window for users who have opted in. For more information, see:  [Marketing Messages](/docs/conversation/channel-support/facebook-messenger/message-support#marketing-messages). |