package MyApp::Controller::Root;
use strict; use warnings;
use parent 'Catalyst::Controller';

__PACKAGE__->config->{ 'namespace' } = '';

sub auto : Private {
    my ( $self, $c ) = @_;

    if ( $c->request->path !~ m{/$} ) {
        $c->response->redirect( $c->request->path.'/' );
        return 0;
    }
    return 1;
}
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I could have sworn there was a plugin out there to do this, but I can't seem to find it now...