Events contain many participants. Each participant can have different states.

The "state" property can be

initial
accepted (participant accepted booking message)
declined (participant declined booking message)
reminded (reminders have been sent)
confirmed (participant confirmed)
not_coming (participant cancelled)
not_coming_needs_reschedule
not_coming_no_reschedule

Example Result:

{
  id: 123,
  calendar_id: 456,
  start_time: "2016-04-15T12:00:00-07:00",
  end_time: "2016-04-15T13:00:00-07:00",
  title: "Appointment with Fred",
  location: "",
  content: "",
  is_deleted: false,
  participants: [ {
    id: 789,
    name: "Fred Smith",
    phone: "650-555-1212",
    normalized_phone: "+16505551212",
    email: "fred@gmail.com",
    state: "initial", 
  }],
  custom_data: {
    field_1: "custom value"
  }
}