NknClient

An Elixir client for sending and receiving messages on NKN. Client defaults to compressed elliptic curve points on NIST P-256. Support for ed25519 will be added in the future once the offical nodes support it.

Automatically reconnects to the correct node from body of the WrongNode messages in accordance with the reference JavaScript Client.

A simple usage example

defmodule User do
  use NknClient

  def start_link(state) do
    NknClient.start_link(__MODULE__, state)
  end

  def handle_packet(packet) do
    Logger.debug("Packet: #{inspect(packet)}")
  end
end

Callback that can be implemented:

• handle_packet/1
• handle_update_chain/1
• handle_set_client/1
• handle_send_packet/1
• handle_raw_block/1

The module User can then be put in a supervision tree or started manually

{:ok, pid} = User.start_link(:ok)

Send packets to other users on the network

iex> User.send_packet("some_address", "Hello, NKN!")
iex> User.send_packet(["some_address", "another_address"], "Hello, NKN!")

Get your own key pair and client id

iex> User.get_keys()
iex> User.get_address()

Config

Any of the fields can be left blank. If client_id is not specified then only the public key will be used for identification. If the private_key is left blank then a new one will be generated every time your application starts. If rpc_url is left blank the current public default one http://testnet-node-0001.nkn.org:30003 will be used.

Do not place your private key in your repository, set it as an environment variable and access it with System.get_env("SECRET_NKN_PRIVATE_KEY").

config :nkn_client, client_id: "elixir_nkn",
                    private_key: "some_private_key",
                    rpc_url: "http://custom_seed_rpc:30003"

Installation

Add nkn_client to your list of dependencies in mix.exs:

def deps do
  [
    {:nkn_client, "~> 0.5.0"}
  ]
end

TODO

• Support client id's in front of the public keys (id.pub_key)
• Let users specify their own private key and calculate corresponding public key
• Make handle functions for each of the different message types
• Can the "Digest" in packages be decoded to reveal information about the relay?
• Add a non-empty Signature to sent messages
• Store the data from updateSigChainBlockHash and expose it through the library API (Callback added)
• Write more tests!
• Declare type specifications on all functions
• Investigate how we can achieve better throughput with our GenStage