my @messages = ();
...
template '...' => {messages => \@messages};

##</code><code>##

sub template        { Dancer::Template::Abstract->template(@_) }

##</code><code>##

sub template {
    my ($class, $view, $tokens, $options) = @_;
    ...

##</code><code>##

my @messages = ();
...
template 'XXX' => {messages => [ @messages ]};