matrix-doc/event-schemas/examples/m.room.member$invite_room_state

{
  "$ref": "m.room.member",
  "content": {
    "membership": "invite",
    "avatar_url": "mxc://example.org/SEsfnsuifSDFSSEF",
    "displayname": "Alice Margatroid"
  },
  "unsigned": {
    "age": 1234,
    "invite_room_state": {
      "$ref": "invite_room_state.json"
    }
  }
}