message_history-8.x-1.x-dev/message_history.routing.yml

message_history.get_last_view:
  path: '/message-history/get_read_timestamps'
  defaults:
    _controller: '\Drupal\message_history\Controller\HistoryController::getReadTimestamps'
  requirements:
    _permission: 'access content'

message_history.read:
  path: '/message-history/{message}/read'
  defaults:
    _controller: '\Drupal\message_history\Controller\HistoryController::read'
  requirements:
    _entity_access: 'message.view'
    message: \d+