Minecraft Protocol

A small implementation of the Minecraft Protocol written in Typescript. It provides a functionality to decode or encode packets and has a Connection class which keeps track of the connection state, compression and encryption. It supports version 1.12.2 and 1.13.2.

mcproto aims to be a relatively low level library that only handles connection related state. Connection related error handling is done outside of the library on the Socket class. mcproto has some basic event callbacks: onDisconnect(reason: any), onLogin(uuid: string, username: string), onPacket(packet: PacketReader) which can be set on the Connection class. Keep in mind that the protocol and packet ids can change from version to version.

This implementation doesn't automatically decode all packets, it does only decode packets that are related to the connection state like set compression or encryption request. For reading packets, the class PacketReader is provided which contains methods for reading common data types.

Packets are written using the PacketWriter class and can be converted to a buffer with the .encode() method. The encoded packet is not prefixed with it's length.

Server List Ping

import { connect } from "net"
import { Connection, PacketWriter } from "mcproto"

const HOST = "play.hivemc.com"

const socket = connect({ host: HOST, port: 25565 }, async () => {
    const client = new Connection(socket)

    client.send(new PacketWriter(0x0).writeVarInt(-1)
    .writeString(HOST).writeUInt16(socket.remotePort)
    .writeVarInt(1))

    client.send(new PacketWriter(0x0))

    const response = await client.nextPacket()
    console.log(response.readString())

    socket.end()
})

More examples can be found in the repository's examples folder.