streams - Communicating with server over Websocket using SocketConnect

I am trying to connect to a web socket feed of Gdax. The documentation is here, https://docs.gdax.com/#websocket-feed. There is no account needed and the information is public. I have successfully connected see this post, SocketConnect not connecting to web socket address

After connection, a subscription message needs to be sent. My json looks exactly like the documentation but not successful.

socket = SocketConnect["ws-feed.gdax.com:80"];

json = ExportString[<|"type" -> "subcribe", 
"product_ids" -> {"ETH-USD", "ETH-EUR"}, 

"channels" -> {"level2", 
  "heartbeat", <|"name" -> "ticker", 
   "product_ids" -> {"ETH-BTC", "ETH-USD"}|>}|>, "JSON"];

WriteString[socket, json]

result = ReadString[socket]

Yields an error message.

HTTP/1.1 400 Bad Request


Date: Wed, 07 Feb 2018 18:14:59 GMT

Content-Type: text/html

Content-Length: 177

Connection: close

Server: cloudflare-nginx


CF-RAY: -










400 Bad Request

cloudflare-nginx

I also tried this as a HTTPRequest and returns same error message. I have also tried the request as a PUT to no avail.

request = HTTPRequest[<|"Body" -> json, Method -> "GET"|>];

WriteString[socket, request]

result = ReadString[socket]