Custom code is easy, you basically just copy and paste code that somebody else has written into the cloud interface to your SmartThings account.
The following FAQ is old but will give you the terms, concepts, and basic approach. ( The topic title is a clickable link)
The problem is we have not yet been given any details about how custom code for Z wave or Zigbee devices (what smartthings calls “hub connected devices“) Will work once the transition to the new architecture is complete. so there is a risk in investing heavily in something which requires that kind of custom code at this time.
