How to access sms history with private frameworks in iOS 8?

I want to access my iPhone's sms history in my application. This is my own application for personal use (Enterprise distribution without jailbreak) and it doesn't exist on apple store so there is no limits for using private frameworks. I have tried some task list below:

1. Reading the sms database -> Didn't work because of sandbox restrictions.
2. Using ChatKit; I saw CKConversationList class that has a method -(id)conversationswhich I guess returns an array of CKConversations. Then I can retreive all the history. The problem is CKConversationList.sharedConversationList().conversations() returns nil when I call it in my app. Although it doesn't return nil when I call it in MobileSMS process (I checked it with a tweak and tested it on a jailbroken phone). I saw a method named +(void)initialize at http://findnerd.com/askquestion/ios I called it before calling the above method but it still doesn't work.
IMCore private framework could be used maybe but I don't know how. Please help me how to access sms history ?