objeto php en objeto JSON anidado

{ "client": {
    "build": "1.0",
    "name": "xxxxxx",
    "version": "1.0"
    },
    "protocolVersion": 4,
    "data": {
        "distributorId": "xxxx",
        "distributorPin": "xxxx",
        "locale": "en-US"
    }
}
Shiny Stork