Kadence represents other peers by using a Bucket~contact pair. Any time an entry in a Bucket is retrieved or placed, it is in the format of a tuple. The item at index 0 is always the string representation of the module:kadence/constants~B size identity key in hexadecimal. The item at index 1 can be any arbitrary JSON serializable object that the transport adapter in use understands.

For example, the HTTPTransport and the UDPTransport both accept an object cotaining hostname and port properties. Other transports may accept whatever they need. When constructing your KademliaNode instance, these properties are set by you as identity and contact. If the identity value is omitted, it will be randomly generated.

Take note that for a stable network, you will need to persist identities generated as nodes store data based on this key.

const node = new kadence.KademliaNode({
  // ...
  identity: Buffer.from('059e5ce8d0d3ee0225ffe982e38f3f5f6f748328', 'hex'),
  contact: {
    hostname: 'my.reachable.hostname',
    port: 1337
  }
});

Since nodes may be using module:kadence/traverse to become addressable on the internet, this Bucket~contact pair is included in every message payload instead of relying on inferred return address information at the transport layer. This makes every JSON-RPC message payload an array, containing a request message at index 0 and a idenity notification at index 1.

[
  {
    "jsonrpc": "2.0",
    "id": "<uuid>",
    "method": "FIND_NODE",
    "params": ["059e5ce8d0d3ee0225ffe982e38f3f5f6f748328"]
  },
  {
    "jsonrpc": "2.0",
    "method": "IDENTITY",
    "params": [
      "059e5ce8d0d3ee0225ffe982e38f3f5f6f748328",
      {
        "hostname": "<reachable hostname>",
        "port": 1337
      }
    ]
  }
]