Hi,
Your question is not very specified. Spectrum provides different APIs like REST, VNMSHell, ReportinfDB-API, Topology-Export as XML ? ..
All Methods to get the data are well documented and discussed int the Community.
To get the devices via REST, You could create a GET or POST-Command to get all (GET) or only specified devices and currently I would say that the REST-API is the best option to filter out the devices which You need. Pelase try to describe Your usecase and the Community will help to do the next step.
Best Regards
Erich