{
  "costCenter": "Quickstart",
  "fileMetadata": [
    {
      "fileName": "letter.pdf",
      "senderName": "REPLACE_ME sender name",
      "documentTitle": "Quickstart test letter",
      "documentReferenceDate": "2026-08-12",
      "documentTypes": ["message"],
      "deliveryChannelPreferences": ["DIGITAL"],
      "allCredentialShouldMatch": false,
      "allRecipientsRequired": true,
      "recipients": [
        {
          "senderUserId": "quickstart-recipient-1",
          "unhashedCredentials": {
            "email": "REPLACE_ME@example.com"
          }
        }
      ]
    }
  ]
}