Kadence implements a generic Messenger class that is used as the interface between the application layer and the AbstractNode~transport. This interface exposes 2 primary members: Messenger~serializer and Messenger~deserializer.

As you might expect, both of these objects are streams. Both are transform streams. The transport adapter's readable end is piped through the deserializer which is then processed by the middleware stack implemented by the AbstractNode. The serializer is piped through the transport adapter's writable end, which dispatches the message.

The serializer and deserializer are metapipe objects (transform streams which are composed of a modifiable stack of transform streams). This means you can extend the behavior of messages processing by simply prepending or appending your own transforms.

By default, these metapipes use a built-in JSON-RPC serializer and deserializer. It is possible to completely change the message format sent over the network if desired by passing KademliaNode your own instance of Messenger using your own serializer and deserializer.

Below is an example of extended the message processing pipeline.

const { Transform } = require('stream');
const node = new kadence.KademliaNode(options);

node.rpc.serializer.prepend(() => new Transform({
  transform function(data, encoding, callback) {

  },
  objectMode: true
}));

node.rpc.deserializer.append(() => new Transform({
  transform: function(data, encoding, callback) {

  },
  objectMode: true
}));

Note that the KademliaRules still expect the deserialized message to include method and params properties (conforming to AbstractNode~request).