Response message format

The subscribe / unsubscribe ack keeps the {id,code,msg} shape, but code is now 200 on success and 400 on failure (e.g. an unknown method, a bad param, or a channel outside the spot domain).

format

{
    "id": "{id}",  //call back ID
    "code": 200,   //result 200=success;400=fail
    "msg": "success"
}

Response-success

{"id": "1", "code": 200, "msg": "success"}

Response-error

{"id": "1", "code": 400, "msg": "invalid param"}