While it doesnt mention “Web Sockets” explicitly, the Docs do mention this…
By default, all assets must be loaded from the Twitch CDN, except the following:
- You can connect to any HTTPS or WSS endpoint (i.e., for purposes of an XHR)
HTTPS = HyperText Transfer Protocol Secure
WSS = Web Socket Secure
So while yes, you can you Web Sockets, they must be a secure web socket connection, just like HTTP requests MUST be HTTPS secure requests.
This is par for the course, however, as there is a large move from HTTP to HTTPS traffic, and Google.com and Chrome, in many cases, are warning users who browse to insecure HTTP hosted websites.