Send a silent push notification to APNS with AWS SNS.

wtf-sns-apns.js

sns.publish({
  TargetArn: device.arn,
  MessageStructure: 'json',
  Message: JSON.stringify({
    default: 'you will never see this muah!',
    APNS_SANDBOX: JSON.stringify({
      aps: {
        'alert': '',
        'content-available': 1
      },
      'event-category': eventname
    })
  })
}, 
function __notifiedAPNS(err, data) {
  console.log(err, JSON.stringify(data, null, 2))
  callback()
})

I found that the only item in aps should be 'content-available': 1. Adding anything else caused the silent push not to be delivered.