You can use the version 1 API calls, but they are considered private and don’t have full support. They aren’t well documented and can change at any time. I recommend using our v3 and beta APIs (in that order) before resorting to the private APIs, as they have much better documentation and are supported for the long term. We are working on adding more functionality to beta and v3 all the time, but if you have a specific request for what you would like to see in our production APIs, please don’t hesitate to reach out and let us know.