Include GUEST_SURNAME in additionalProperties for tender API search responses

Your tender API integration should include the guest's surname (last name or family name) using theGUEST_SURNAME tenderPropertyType, within the additionalProperties array of tender search responses (not the properties array).

This is required to support guest room charge workflows on Toast kiosk devices and Toast Mobile Order & Pay. These workflows let guests charge purchases to their rooms by entering their surname and room number directly, with no operator intervention. The Toast platform matches this information to your tender search response to process the charge, and the matching logic requires the surname to be isolated in the GUEST_SURNAME value rather than embedded in a full name string.

The Toast platform matching logic tolerates minor differences in the surname value, including case (smith matches Smith), extra spaces, and punctuation.

For example, when returning tender search results, include the guest's surname within additionalProperties:

{
  "searchResponse": {
    "searchResults": [
      {
        "tenderIdentifier": "CH20009529016",
        "properties": [
          {
            "key": "Name",
            "value": "John Smith",
            "tenderPropertyType": "OTHER"
          },
          {
            "key": "Room Number",
            "value": "305",
            "tenderPropertyType": "ROOM_ID"
          }
        ],
        "additionalProperties": [
          {
            "key": "Surname",
            "value": "Smith",
            "tenderPropertyType": "GUEST_SURNAME"
          }
        ]
      }
    ]
  }
}