I want user id of the subscribers. In the documentation, it only shows the callbacks like :
{
"event":"conversation_started",
"timestamp":1457764197627,
"message_token":4912661846655238145,
"type":"open",
"context":"context information",
"user":{
"id":"01234567890A=",
"name":"John McClane",
"avatar":"http://avatar.example.com",
"country":"UK",
"language":"en",
"api_version":1
},
"subscribed":false
}