Calling Objective-c/Cocoa app with Ruby

I am using Ruby on Rails to write a web-service. Basically, I have an objective-c/Cocoa app running in the ba开发者_开发问答ckground in the server, and when a request comes in, I need to delegate it to the app. How can I do that? Is it even possible?

Either the app itself needs to act as a server that the Ruby app can talk to (not necessarily a Web server, but it needs to have some interface for the Ruby app to interact with), or you'll need to talk to it with Apple Events. For the latter option, see rb-appscript.