&gt;  the execution of middlewares when a user publishes a message (to filter them or something else)<p>You can do that with nchan: <a href="https:&#x2F;&#x2F;nchan.slact.net&#x2F;details#authenticate-with-nchan_authorize_request" rel="nofollow">https:&#x2F;&#x2F;nchan.slact.net&#x2F;details#authenticate-with-nchan_auth...</a><p>&gt;  Right now, I&#x27;m using two websockets, one to Nginx PushStream only to receive messages and another to the NodeJS server to publish messages.<p>You can also multiplex several websockets into one for the client.<p>I can&#x27;t offer you a standalone server, but I can offer some pretty fancy features : )