Using the API, in the sandbox environment. Can I obtain full access to my companies data?

Using the API, in the sandbox environment. Can I obtain full access to my companies data? As of right now, I can make calls using the API to see call logs but there is not data. I want to be able to pull the live data. is it possible? , Using the API, in the sandbox environment. Can we obtain full access to my company's data? If not is it possible to do so? As of right now call logs are empty...