The answer is yes, but the specific solution depends on what you are asking to do. If you want to know how tobring a previously made FloorSpaceJS plan into an OpenStudio model with the command line, you can use the Merge FloorspaceJS with Model measure.
The FloorSpaceJS file that is taken as an input to this measure could have been made in the OpenStudio Application or in another deployment such as this web development deployment.
If you are asking about using a command line to create and alter FloorSpaceJS files, it is in the end a JSON file and someone could develop methods to generate or alter them with a command line, but I'm not sure if anyone has.
If you question wasn't able FloorSpaceJS and you were looking for something more like the digram to spaces in the SketchUp plugin, there are also some options. OpenStudio has a native function space = OpenStudio::Model::Space.fromFloorPrint(point3dVector, height, model)
that results in a single space. The openstudio-extension gem, included with OpenStudio, has methods that build on this to convert a collection of polygons representing the building into a multi-story model such as makeSapcesFromPolygons method. This can be run multiple times when different stories in the building have unique floor plans, similar to how spaces from diagrams can be run multiple times in the SketchUp plugin.
Your question reads space to digram, which would be possible, but I assume you are asking the reverse, how to go from a digram to spaces. If that isn't the case let me know and I'll modify the answer.