Try https://channelstream.org/ https://channelstream.org/ - you can talk via rest calls to it - it scales up to thousands of connections on a single small machi

Try https://channelstream.org/ https://channelstream.org/ - you can talk via rest calls to it - it scales up to thousands of connections on a single small machine. You have tiny JS WS/long pool clients available with reconnection logic or you can roll your own if you like.