MSMP Lib

A library that extends the Minecraft Server Management Protocol (MSMP) by allowing for custom methods and notifications to be registered with the MSMP registry. Easy to use, customizable, and extensible.

Installation

Add the following to your build.gradle:

repositories {
    maven { url = uri("https://jitpack.io") }
}

dependencies {
    implementation("com.github.YOUR_USERNAME:msmp-lib:VERSION")
}

And declare the dependency in your fabric.mod.json:

"depends": {
    "msmp-lib": "*"
}

Usage

1. Define your payloads

Payloads are simple records that describe the data sent and received over MSMP. Each payload needs a Codec for serialization and a Schema for MSMP discovery.

public record PingPayload(String message) {

    public static final Codec<PingPayload> CODEC = RecordCodecBuilder.create(i -> i.group(
        Codec.STRING.fieldOf("message").forGetter(PingPayload::message)
    ).apply(i, PingPayload::new));

    public static final Schema<PingPayload> SCHEMA = Schema.record(CODEC)
        .withField("message", Schema.STRING_SCHEMA);
}

2. Initialize in your mod

Create a MSMPServer instance in the SERVER_STARTED lifecycle event. Use namespace() to register methods and notifications, and send() to broadcast notifications.

public class MyMod implements ModInitializer {

    private static MSMPServer msmp;
    private static MSMPNotification<PingPayload> ping;

    @Override
    public void onInitialize() {
        ServerLifecycleEvents.SERVER_STARTED.register(server -> {
            msmp = new MSMPServer(server);

            ping = msmp.namespace("my_mod")
                .notification("ping", PingPayload.SCHEMA, "A ping notification");

            msmp.namespace("my_mod")
                .method("echo",
                    EchoPayload.SCHEMA,
                    EchoPayload.SCHEMA,
                    "Echoes a message back to the client",
                    (server, params, client) -> {
                        System.out.println("Called by connection: " + client.connectionId());
                        return params;
                    }
                );
        });

        ServerLifecycleEvents.SERVER_STOPPED.register(server -> {
            msmp = null;
        });
    }

    // Broadcast a notification to all connected clients
    public static void sendPing() {
        if (msmp != null) msmp.send(ping, new PingPayload("hello"));
    }
}

Handler parameters

The method handler receives three parameters:

Parameter	Type	Description
server	MinecraftServer	The running Minecraft server instance
params	Param	The payload received from the client
client	ClientInfo	Info about the calling client, including connectionId()

JSON-RPC examples

Calling a method (my_mod:echo):

{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "my_mod:echo",
    "params": [{
        "message": "hello"
    }]
}

Response:

{
    "jsonrpc": "2.0",
    "id": 1,
    "result": {
        "message": "hello"
    }
}

Receiving a notification (my_mod:notification/ping):

{
    "jsonrpc": "2.0",
    "method": "my_mod:notification/ping",
    "params": [{
        "message": "hello"
    }]
}

Requirements

• Minecraft with MSMP enabled (management-server-enabled=true in server.properties)
• The Management Server listens on localhost:25576 by default

License

LGPL-3.0