mutation CreateEventAnnouncement($input: CreateEventAnnouncementInput!) {
  createEventAnnouncement(input: $input) {
    announcement {
      bodyHtml
      bodyText
      createdAt
      externalLink
      id
      post {
        __typename
        ... on Event {
          __typename
        }
      }
    }
    clientMutationId
    errors
  }
}

{
  "input": {
    "body": "string",
    "eventId": "id",
    "rsvpStatuses": [
      "MAYBE"
    ]
  }
}

{
  "data": {
    "createEventAnnouncement": {
      "announcement": {
        "bodyHtml": "string",
        "bodyText": "string",
        "createdAt": "value",
        "externalLink": "string",
        "id": "id",
        "post": {
          "__typename": "Event"
        }
      },
      "clientMutationId": "string",
      "errors": [
        "string"
      ]
    }
  }
}