Is it possible to composer a BPMN document from scratch using nayra?

I use bpmn-js a lot to create bpmn processes on the front-end, but I'm interested in being able to do the same thing, programatically, on the backend, and then export to a bpmn compliant xml file that can be read by bpmn-js.

Is it possible to do this currently with this library?

If so, is there any examples of this anywhere that I could look at?

Many thanks!