How to get the client osc-port

I'm aware of the globals.url function to get the IP:PORT defined in the send address of the session. But is there any way to get the osc-port ?

You could read it from a custom module and send it to a variable widget:

var oscPort = settings.read('osc-port') || settings.read('port') || 8080
app.on('sessionOpened', ()=>{
  receive('/variable_widget_address', oscPort)
})
/*
// that'd be the message filtering part of the module 
module.exports = {

}
*/