Actually I started wiriting one MooseX::Embody::JSON and MooseX::Embody::JSON::Role

This allows me to do things exactly I would expect it:

package WebService::DreamWidth::Entry;

use Moose;
use MooseX::Embody::JSON;

use WebService::DreamWidth::Icon;
use WebService::DreamWidth::Poster;

# this one is not part of Embody::Json yet
has "tags" => (is=>'ro', isa => 'ArrayRef[Str]');

j_obj "icon" =>(class => "WebService::DreamWidth::Icon", is =>'ro');
j_obj "poster" =>(class => "WebService::DreamWidth::Poster", is =>'ro'
+);

j_attr "security" => (is => 'ro');
j_attr "body_html"=> (is => 'ro');
j_attr "subject_raw"=> (is => 'ro');
j_attr "subject_html"=> (is => 'ro');
j_attr "allowmask"=> (is => 'ro');
j_attr "body_raw"=> (is => 'ro');
j_attr "icon_keyword"=> (is => 'ro');
j_attr "entry_id"=> (is => 'ro');
j_attr "datetime"=> (is => 'ro');
j_attr "url" => (is => 'ro');
[download]

This is early prototype, I need to play with it a lot, before releasing in even as beta, and some internals may be needs changing a log, but is is exactly the thing I think is needed for creating JSON-based REST clients.

And yes, comments and suggestion are appreciated.