On the server side i've a service which is using JSONRPC protocol. So, this service expects to have an object serialized with JSON inside a POST request body. I can communicate with the service "by hands" with standard Ext.Ajax.request method which have jsonData parameter for that. But, what should i do in case of a store? I don't see any jsonData parameter in JSON Proxy methods, how can i force a store to send data represented as an object inside POST body?