 <p>This is not a cross-domain issue. You are mixing the <em>dynamic proxy</em> and <em>proxyless</em> approaches. <code>$.hubConnection</code> and <code>createHubProxy</code> are from the proxyless API, but <code>.client</code> is available only with dynamic proxies. Check <a href="http://www.asp.net/signalr/overview/signalr-20/hubs-api/hubs-api-guide-javascript-client#establishconnection" rel="nofollow">the documentation about both</a> and you will be able to fix it (I don't go further with code because I do not know which approach you really want to use). </p>