Kitteh IRC Client Library Documentation

The Kitteh IRC Client Library (KICL) is a powerful, modern IRC library written in Java. Built with NIO using the Netty library, KICL aims to maximize performance and scalability.

Some niceties about KICL include:

  • Events model for handling information from the server.
  • Built with Java 8. Supporting streams, functions, and Optional.
  • Full TLS support.
  • WEBIRC authentication.
  • Fully featured CTCP support.
  • Rather comprehensive IRCv3 support including:
    • CAP negotiation.
    • Account tracking with combined power of account-notify, extended-join, and WHOX.
    • Away status tracking with away-notify.
    • More accurate mode tracking with multi-prefix.
  • Flexible authentication:
    • SASL, NickServ, and GameSurge's AuthServ supported out-of-the-box.
    • Custom authentication protocols can be easily written and registered.

Getting started

KICL is designed with a simple and intuitive API. A hello world is as simple as:

public class HelloKitteh {
    public static void main(String[] args) {
        Client client = Client.builder().nick("KittehBot").server().host("").then().buildAndConnect();

        client.sendMessage("", "Hello World!");

Note: By default KICL connects over TLS, which requires additional setup on certain networks.


Check the common problems page for some common situations.

It can be useful to see input, output, and exceptions thrown while developing. Use the Client.Builder to set listeners to catch these little surprises. Here is a simple example, printing all of the info to the console:

public class DebugKitteh {
    public static void main(String[] args) {
        Client.Builder builder = Client.builder();

        SimpleDateFormat sdf = new SimpleDateFormat("mm:ss");
        builder.listeners().input(line -> System.out.println(sdf.format(new Date()) + ' ' + "[I] " + line));
        builder.listeners().output(line -> System.out.println(sdf.format(new Date()) + ' ' + "[O] " + line));
        // and then build() or buildAndConnect()

Using KICL in your project

KICL is built and deployed using Maven. Releases are available on Maven Central. Adding it as a dependency is simple as adding the lines below to your pom.xml file:


Or, for Gradle:

implementation "org.kitteh.irc:client-lib:8.0.0"


KICL uses a simple event system driven by @Handler annotations. A simple event listener example is shown below. For more information on events, see the Events documentation.

public class FriendlyBot {
    private Client client;

    public void connect() {
        // Set up this.client before the below line!


    public void onJoin(ChannelJoinEvent event) {
        Channel channel = event.getChannel();
        channel.sendMessage("Hi " + event.getUser().getNick() + "!");

More information

Consult the JavaDocs to answer most questions.

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