Discord4J

A fast, reactive Java wrapper for the official Discord Bot API.

Built with Reactor, Netty, and a focus on flexibility, Discord4J provides an effective, non-blocking interface for creating Discord bots. The reactive and asynchronous nature of the library allows for scalability through backpressure handling and the efficient use of resources. Its modularized structure gives the user the ability to tailor their experience to different levels of abstraction and pick the right tools for the job.

Installation

Current stable releases are from 3.0.x. Check the branch for instructions.

Instructions to use our latest pre-releases from master branch (3.1.x):

Gradle

repositories {
  mavenCentral()
}

dependencies {
  implementation 'com.discord4j:discord4j-core:3.1.0.M2'
}

Maven

<dependencies>
  <dependency>
    <groupId>com.discord4j</groupId>
    <artifactId>discord4j-core</artifactId>
    <version>3.1.0.M2</version>
  </dependency>
</dependencies>

SBT

libraryDependencies ++= Seq(
  "com.discord4j" % "discord4j-core" % "3.1.0.M2"
)

Dependencies

• Reactor Core 3.3
• Reactor Netty 0.9
• Jackson Databind 2.11

Quick Example

Coming from v3.0.x? Check our Migration Guide (work in progress)

Reactive

DiscordClient.create(System.getenv("token"))
        .withGateway(client -> {
            client.getEventDispatcher().on(ReadyEvent.class)
                    .subscribe(ready -> System.out.println("Logged in as " + ready.getSelf().getUsername()));

            client.getEventDispatcher().on(MessageCreateEvent.class)
                    .map(MessageCreateEvent::getMessage)
                    .filter(msg -> msg.getContent().equals("!ping"))
                    .flatMap(Message::getChannel)
                    .flatMap(channel -> channel.createMessage("Pong!"))
                    .subscribe();

            return client.onDisconnect();
        })
        .block();

Blocking

DiscordClient.create(System.getenv("token"))
        .withGateway(client -> {
            client.on(ReadyEvent.class)
                    .subscribe(ready -> System.out.println("Logged in as " + ready.getSelf().getUsername()));

            client.on(MessageCreateEvent.class)
                    .subscribe(event -> {
                        Message message = event.getMessage();
                        if (message.getContent().equals("!ping")) {
                            message.getChannel().block().createMessage("Pong!").block();
                        }
                    });

            return client.onDisconnect();
        })
        .block();

Check out more examples here

Modules

Discord4J is highly oriented towards customizability. To achieve this, the project is divided into several "modules" which can be used separately depending on your use case.

Core

The core module combines the other modules to form high-level abstractions for the entire Discord Bot API. This is the module most users will want when making bots.

Rest

The rest module provides a low-level HTTP client specifically for Discord which properly handles Discord's ratelimiting system.

Gateway

The gateway module provides a low-level WebSocket client for interacting with the Discord Gateway.

Voice

The voice module provides a client to manipulate audio through Voice Connections.

Common

The common module contains base utilities and models useful for other modules.

Stores

Discord4J's mechanism for storing information received on the gateway is completely pluggable. This allows both the ability to customize what is stored and how. The Stores repository contains some pre-made implementations as well as the API for making your own.

Useful Links

• Discord4J Site
• Discord4J Wiki
• Javadoc
• Reactor 3 Reference Guide

Snapshots

Development builds can be obtained from Sonatype Snapshots repository or Jitpack.

Make sure you have the appropriate repositories, using Gradle:

Gradle

repositories {
  maven { url 'https://oss.sonatype.org/content/repositories/snapshots' }
  mavenCentral()
}

dependencies {
  implementation 'com.discord4j:discord4j-core:3.1.0-SNAPSHOT'
}

Maven

<repositories>
    <repository>
        <id>oss.sonatype.org-snapshot</id>
        <url>http://oss.sonatype.org/content/repositories/snapshots</url>
        <snapshots>
            <enabled>true</enabled>
        </snapshots>
    </repository>
</repositories>

<dependencies>
    <dependency>
        <groupId>com.discord4j</groupId>
        <artifactId>discord4j-core</artifactId>
        <version>3.1.0-SNAPSHOT</version>
    </dependency>
</dependencies>