The general wisdom is to start by keeping everything in one package. An “endpoint” will resolve to a function or method in a package. As you develop to support all 1000 endpoints it should become clear how to reorganize and break it into multiple packages. Perhaps one package for all customer endpoints, for example. If you have nginx or similar to direct the traffic, then it is simpler to break apart the packages without breaking your RESTful API. Even without nginx, it isn’t that hard.
Hope this helps!