[slact]

> the execution of middlewares when a user publishes a message (to filter them or something else)

You can do that with nchan: https://nchan.slact.net/details#authenticate-with-nchan_auth...

> Right now, I'm using two websockets, one to Nginx PushStream only to receive messages and another to the NodeJS server to publish messages.

You can also multiplex several websockets into one for the client.

I can't offer you a standalone server, but I can offer some pretty fancy features : )

[geekuillaume]

I saw this feature, but I think there is limitation preventing me to use it, tell me if I'm wrong ;) - I cannot use this to make a call each time a message is published on a pubsub websocket - I cannot modify the message sent by the user (to add user information for example)

Also, what do you mean by multiplexing websockets ?

[slact]

That's correct, that feature is for authentication only. I may add a feature to replace the message with the back end response.

By multiplexing I mean that a single websocket (or any other) subscriber can subscribe to multiple channels.