The node.js SDK is best suited for web applications or bots. It does not support acting as WebRTC endpoint, but support starting a conference, dialing out a number or user on behalf of the logged in user, recording, etc.
Since the node.js SDK is internally using the regular JS SDK, asynchroneous eventing as also available.
The source of the examples below are on github.com/circuit and are hosted via rawgit. When running the examples you will be asked to sign in with a Circuit sandbox account. You can register for a free account on the Circuit Portal.
The API is identical to the JS SDK.API Documenation
Introduction example. Shows how to logon to circuit, register for events, lookup a conversation, send a message, attach files to a message, send a comment.Source
more to come...