This REST API implements calls for retrieving reports.
It contains a much improved set of calls for assembling an X Report / Z Report (cashier's shift summary).
There is an article that explains how the different calls of Reports API correspond to sections on the standard X / Z Report that can be printed from back office.
Each endpoint also provides Swagger documentation. For an example, see the documentation provided by the sandbox endpoint:
"clientCode"
and "sessionKey"
.)