| Name | Type | Description | Notes |
|---|---|---|---|
| type | string | Button type. phone is Facebook only. | |
| title | string | Button label (max 20 chars) | |
| url | string | URL for url-type buttons | [optional] |
| payload | string | Payload for postback-type buttons | [optional] |
| phone | string | Phone number for phone-type buttons (Facebook only) | [optional] |