json.payload @attachments do |attachment|
  json.message_id attachment.push_event_data[:message_id]
  json.thumb_url attachment.push_event_data[:thumb_url]
  json.data_url attachment.push_event_data[:data_url]
  json.file_size attachment.push_event_data[:file_size]
  json.file_type attachment.push_event_data[:file_type]
  json.extension attachment.push_event_data[:extension]
  json.created_at attachment.message.created_at.to_i
  json.sender attachment.message.sender.push_event_data if attachment.message.sender
end
