Or do completely the opposite: have your Dancer2 app accept only CLI commands as parameter which then delegates to your CLI. Which means: write first your CLI parser and functions, then worry about how to communicate with it. If you write it as a module, you could do something like my $cli = new CLI($params); my $res = $cli->process($commands, $data); either from a Dancer2 app or from a socket listener or from the command line.