Send sms from Cocoa application

I want to make a simple program to send SMS from osX. I know there's a开发者_开发知识库lready something available on the web, but I want to code it by myself. I need to know if there's any useful API to write this with Cocoa or how to send AT commands to any discovered device. Thank you.

A quick Google search for "send sms cocoa" swisssms. "SwissSMS is a Mac OS X front-end to SMS operators services." ... looks promising.