JSON.pm

package JSONTest::Controller::JSON;

use strict;
use warnings;

use base 'Catalyst::Controller';

sub echo : JSONRPCPath('/echo') {
        my ($self, $c, @args) = @_;
        $c->stash->{jsonrpc} = join ', ', @args;
}

1;

JSONTest.pm

package JSONTest;

use strict;
use warnings;

use Catalyst::Runtime '5.70';

use parent qw/Catalyst/;
use Catalyst qw/-Debug
                ConfigLoader
                Static::Simple
                Server
                Server::JSONRPC
/;
our $VERSION = '0.01';

__PACKAGE__->config( name => 'JSONTest',
        jsonrpc => {
                path => qr!^(/?)jsonrpc(/|$)!, # This is the "entrypoint" URL.
        },
 );

__PACKAGE__->setup();

1;