While you've got lots of field types and that's a great thing about Gravity Forms you can never meet everyone's specialized needs so I assumed you'd have an API/set of hooks to allow a developer to define a new field type but I've looked all over your website and even in the code and best I can tell there isn't one.
If I missed it can you please point me to the docs and if it isn't there any chance you could add this sooner than later? Much thanks in advance.