Standard input is empty

{
    "items": {
        "post": {
            "categories": [
                {
                    "Baby": {
                        "details": [
                            {
                                "title": "trying with category id again",
                                "price": "3344.55",
                                "date_time": "2013-11-11 17:33:49",
                                "description": "Descriptor sb",
                                "category_id": "3"
                            }
                        ]
                    }
                }
            ]
        }
    }
}