signature_app.pl

use 5.20.0;
use feature qw(postderef signatures);
use Mojolicious::Lite;
use PadWalker 'peek_sub';

hook around_action => sub ($next, $c, $action, @) {
  my @params = sort grep {s/^\$param_//} keys peek_sub($action)->%*;
  return $c->$action($c->param(\@params));
};

get '/' => sub ($self, $param_a, $param_b) {
  $self->render(json => {a => $param_a, b => $param_b});
};

app->start;