malformed JSON string, neither array, object, number, string or atom, at character offset 0 (before "(end of string)") at /home/mojo/perl5/perlbrew/perls/perl-5.22.0/lib/site_perl/5.22.0/JSON/Schema.pm line 48.

#!/usr/bin/env perl
use Mojolicious::Lite;
use Mojo::JSON qw(decode_json encode_json);
use JSON::Schema;
use Mojo::UserAgent;

get '/address' => sub {
  my $self = shift;
  my $ua = Mojo::UserAgent->new;
  my $schema = $ua->get('http://json-schema.org/card')->res->body;
  my $validator = JSON::Schema->new($schema);
  my $contact = encode_json {
   fn        => 'Toby Inkster',
   nickname  => 'TOBYINK',
   email     => { value => 'tobyink@cpan.org' },
   adr       => { countryName => 'England', region => 'East Sussex' },
 };
 my $valid = $validator->validate($contact);
if ($valid) {
   $self->render(text => $contact, status => 200);
   exit;
 }
};