{
  "$ref": "m.room.member.yaml",
  "content": {
    "membership": "knock",
    "avatar_url": "mxc://example.org/SEsfnsuifSDFSSEF",
    "displayname": "Alice Margatroid",
    "reason": "Looking for support"
  },
  "unsigned": {
    "age": 1234,
    "knock_room_state": {
      "$ref": "knock_room_state.json"
    }
  }
}