When you include machina.postal.js in your project, it hooks into the "newFsm" event that gets fired anytime a new FSM is created. In the handler for the "newFsm" event, the machina.postal plugin subscribes to postal, using the FSM's namespace as a channel name, and a wildcard "#" as the topic (will match ANY topic on that channel). From that point on, if anyone publishes a message on the FSM's channel, with a topic that matches the name of a handler, the FSM will call handle, routing the message payload to the handler name (assuming one exists under the current state) which matches the message topic. Voila! Your application components can now interact with the FSM over the message bus, and not require a direct reference to it. But wait, there's more.