In order to communicate with a running Storyboard application the external application must first attach to the application's Storyboard IO channel.  By default this channel is named after the deployment bundle file (i.e. [bundlename].gapp), however the name of this channel can be customized by specifying -ogreio,channel=newname as an option to sbengine. Alternatively, on some platforms, it is also possible to set a GREIONAME environment variable to the channel name.

Once the channel name is determined, the connection to the channel can be established with the gre_io_open() function. This will connect to the channel and return a handle that can be used for future communication.

Once the application has determined that no further communication is necessary the channel should be closed via the gre_io_close() function.