Miva - mvt:call POST Raw JSON Data
<?php
$json = file_get_contents("php://input");
$data = json_decode($json);
var_dump($data);
?>
<mvt:item name="ry_toolbelt" param="assign|g.Json_String|Json_Stringify(l.all_settings:basket)" />
<mvt:call method="'raw'" action="'http://www.example.com/php/process.php'" content-type="'application/json'" fields="'Json_String'">
<mvt:eval expr= "s.callvalue" />
</mvt:call>