API Not Fully Inclusive

Some aspects of Zephyr Scale are not accessible via the API. For example, the attachments section of Zephyr Scale are not accessible with the current Zephyr Scale API. I see an old link app.tm4j.smartbear.com/backend/rest/tests/2.0/testcase/, that looks like it uses the old API. If so, where can I find documentation for that API, or is it possible to expand the scope of the new API to allow functions like accessing attachments?