minecraft protocol

Parse and serialize minecraft packets, plus authentication and encryption.

Features

Supports Minecraft version 1.7.6
Parses all packets and emits events with packet fields as JavaScript objects.
Send a packet by supplying fields as a JavaScript object.
Client
- Authenticating and logging in
- Encryption on and encryption off
- Both online and offline mode
- Respond to keep-alive packets.
- Ping a server for status
Server
- Offline mode
- Encryption and online mode
- Handshake
- Keep-alive checking
- Ping status
Robust test coverage. See Test Coverage section below.
Optimized for rapidly staying up to date with Minecraft protocol updates.

Projects Using node-minecraft-protocol

mineflayer - create minecraft bots with a stable, high level API.
mcserve - runs and monitors your minecraft server, provides real-time web interface, allow your users to create bots.

Usage

Echo client example

var mc = require('minecraft-protocol');
var client = mc.createClient({
  host: "localhost",   // optional
  port: 25565,         // optional
  username: "email@example.com",
  password: "12345678",
});
client.on('chat', function(packet) {
  // Listen for chat messages and echo them back.
  var jsonMsg = JSON.parse(packet.message);
  if (jsonMsg.translate == 'chat.type.announcement' || jsonMsg.translate == 'chat.type.text') {
    var username = jsonMsg.using[0];
    var msg = jsonMsg.using[1];
    if (username === client.username) return;
    client.write(0x03, {
      message: msg
    });
  }
});

If the server is in offline mode, you may leave out the password option.

Hello World server example

var mc = require('minecraft-protocol');
var server = mc.createServer({
  'online-mode': true,   // optional
  encryption: true,      // optional
  host: '0.0.0.0',       // optional
  port: 25565,           // optional
});
server.on('login', function(client) {
  client.write('login', {
    entityId: client.id,
    levelType: 'default',
    gameMode: 0,
    dimension: 0,
    difficulty: 2,
    maxPlayers: server.maxPlayers
  });
  client.write('position', {
    x: 0,
    y: 1.62,
    z: 0,
    yaw: 0,
    pitch: 0,
    onGround: true
  });
  var msg = { translate: 'chat.type.announcement', using: [
    'Server',
    'Hello, ' + client.username
  ]};
  client.write(0x03, { message: JSON.stringify(msg) });
});

Installation

npm install minecraft-protocol

On Windows, first follow the Windows instructions from Obvious/ursa

Documentation

mc.ping(options, callback)

callback(err, pingResults)

pingResults:

prefix
protocol
version
motd
playerCount
maxPlayers

mc.createServer(options)

Returns a Server instance and starts listening.

Server

server.onlineModeExceptions

This is a plain old JavaScript object. Add a key with the username you want to be exempt from online mode or offline mode (whatever mode the server is in).

Make sure the entries in this object are all lower case.

server.clients

Javascript object mapping a Client from a clientId.

server.playerCount

The amount of players currently present on the server.

server.maxPlayers

The maximum amount of players allowed on the server.

server.motd

The motd that is sent to the player when he is pinging the server

server.favicon

A base64 data string representing the favicon that will appear next to the server on the mojang client's multiplayer list.

mc.createClient(option)

Returns a Client instance and perform login

Client

client.state

The internal state that is used to figure out which protocol state we are in during packet parsing. This is one of the protocol.states.

client.isServer

True if this is a connection going from the server to the client, False if it is a connection from client to server.

client.socket

Returns the internal nodejs Socket used to communicate with this client.

client.uuid

A string representation of the client's UUID. Note that UUIDs are unique for each players, while playerNames, as of 1.7.7, are not unique and can change.

client.username

The user's username.

client.session

The user's session, as returned by the Yggdrasil system.

Not Immediately Obvious Data Type Formats

Note : almost all data formats can be understood by looking at the packet structure in lib/protocol.js

entityMetadata

Value looks like this:

[
  {type: 'slot', value: slot, key: 3},
  {type: 'int', value: value, key: 4},
  ...
]

Where the key is the numeric metadata key and the value is the value of the correct data type.

Testing

Ensure your system has the java executable in PATH.
Download the appropriate version of minecraft_server.jar.
MC_SERVER_JAR=path/to/minecraft_server.jar MC_USERNAME=email@example.com MC_PASSWORD=password npm test

Test Coverage

  packets
    √ handshaking,ServerBound,0x00
    √ status,ServerBound,0x00
    √ status,ServerBound,0x01
    √ status,ClientBound,0x00
    √ status,ClientBound,0x01
    √ login,ServerBound,0x00
    √ login,ServerBound,0x01
    √ login,ClientBound,0x00
    √ login,ClientBound,0x01
    √ login,ClientBound,0x02
    √ play,ServerBound,0x00
    √ play,ServerBound,0x01
    √ play,ServerBound,0x02
    √ play,ServerBound,0x03
    √ play,ServerBound,0x04
    √ play,ServerBound,0x05
    √ play,ServerBound,0x06
    √ play,ServerBound,0x07
    √ play,ServerBound,0x08
    √ play,ServerBound,0x09
    √ play,ServerBound,0x0a
    √ play,ServerBound,0x0b
    √ play,ServerBound,0x0c
    √ play,ServerBound,0x0d
    √ play,ServerBound,0x0e
    √ play,ServerBound,0x0f
    √ play,ServerBound,0x10
    √ play,ServerBound,0x11
    √ play,ServerBound,0x12
    √ play,ServerBound,0x13
    √ play,ServerBound,0x14
    √ play,ServerBound,0x15
    √ play,ServerBound,0x16
    √ play,ServerBound,0x17
    √ play,ClientBound,0x00
    √ play,ClientBound,0x01
    √ play,ClientBound,0x02
    √ play,ClientBound,0x03
    √ play,ClientBound,0x04
    √ play,ClientBound,0x05
    √ play,ClientBound,0x06
    √ play,ClientBound,0x07
    √ play,ClientBound,0x08
    √ play,ClientBound,0x09
    √ play,ClientBound,0x0a
    √ play,ClientBound,0x0b
    √ play,ClientBound,0x0c
    √ play,ClientBound,0x0d
    √ play,ClientBound,0x0e
    √ play,ClientBound,0x0f
    √ play,ClientBound,0x10
    √ play,ClientBound,0x11
    √ play,ClientBound,0x12
    √ play,ClientBound,0x13
    √ play,ClientBound,0x14
    √ play,ClientBound,0x15
    √ play,ClientBound,0x16
    √ play,ClientBound,0x17
    √ play,ClientBound,0x18
    √ play,ClientBound,0x19
    √ play,ClientBound,0x1a
    √ play,ClientBound,0x1b
    √ play,ClientBound,0x1c
    √ play,ClientBound,0x1d
    √ play,ClientBound,0x1e
    √ play,ClientBound,0x1f
    √ play,ClientBound,0x20
    √ play,ClientBound,0x21
    √ play,ClientBound,0x22
    √ play,ClientBound,0x23
    √ play,ClientBound,0x24
    √ play,ClientBound,0x25
    √ play,ClientBound,0x26
    √ play,ClientBound,0x27
    √ play,ClientBound,0x28
    √ play,ClientBound,0x29
    √ play,ClientBound,0x2a
    √ play,ClientBound,0x2b
    √ play,ClientBound,0x2c
    √ play,ClientBound,0x2d
    √ play,ClientBound,0x2e
    √ play,ClientBound,0x2f
    √ play,ClientBound,0x30
    √ play,ClientBound,0x31
    √ play,ClientBound,0x32
    √ play,ClientBound,0x33
    √ play,ClientBound,0x34
    √ play,ClientBound,0x35
    √ play,ClientBound,0x36
    √ play,ClientBound,0x37
    √ play,ClientBound,0x38
    √ play,ClientBound,0x39
    √ play,ClientBound,0x3a
    √ play,ClientBound,0x3b
    √ play,ClientBound,0x3c
    √ play,ClientBound,0x3d
    √ play,ClientBound,0x3e
    √ play,ClientBound,0x3f
    √ play,ClientBound,0x40

  client
    √ pings the server (32734ms)
    √ connects successfully - online mode (23367ms)
    √ connects successfully - offline mode (10261ms)
    √ gets kicked when no credentials supplied in online mode (18400ms)
    √ does not crash for 10000ms (24780ms)

  mc-server
    √ starts listening and shuts down cleanly (73ms)
    √ kicks clients that do not log in (295ms)
    √ kicks clients that do not send keepalive packets (266ms)
    √ responds to ping requests (168ms)
    √ clients can log in and chat (158ms)
    √ kicks clients when invalid credentials (680ms)
    √ gives correct reason for kicking clients when shutting down (123ms)


  111 tests complete (3 minutes)

Debugging

You can enable some protocol debugging output using NODE_DEBUG environment variable:

NODE_DEBUG="minecraft-protocol" node [...]

History

0.12.1

Updated protocol version to support 1.7.6

0.12.0

Updated protocol version to support 1.7.2
Overhaul the serializer backend to be more general-purpose and future-proof.
Support listening packets by name (thanks deathcap)
Support reading/writing a raw buffer to the socket.

0.11.6

Updated protocol version to support 1.6.4 (thanks Matt Bell)

0.11.5

Fix handling of some conditional fields (thanks Florian Wesch)

0.11.4

Chat packet string max length fix (thanks Robin Lambertz)

0.11.3

packet 0x2c: packet writing fixed, UUID format simplified, tests updated

0.11.2

1.6.2 support fixes: updated 0x2c packets to include elementList and added 0x85 Tile Editor Open packets

0.11.1

support minecraft protocol 1.6.2 / protocol version 74 (thanks Matt Bell)

0.11.0

support minecraft protocol 1.6.1 / protocol version 73 (thanks Matt Bell)
- note: chat packets have a new format (see the examples for how to upgrade).

0.10.1

support minecraft protocol 1.5.2 / protocol version 61

0.10.0

Added SRV record support when connecting to a server (thanks Matt Stith)
0x66: shift renamed to mode and changed from bool to byte

0.9.0

0xce: create changed from bool to byte (thanks Robin Lambertz)

0.8.1

fix buffer length checking bug in readSlot() (thanks Xabier de Zuazo)
fix C2 calculation bug (fixed #35) (thanks Xabier de Zuazo)
fix oob Buffer at readEntityMetadata (fixed #40) (thanks Xabier de Zuazo)

0.8.0

fix remaining bugs for 1.5.1 protocol (thanks Xabier de Zuazo)
writing packets is 6% faster (thanks Matt Bell)

0.7.9

support minecraft protocol 1.5 / protocol version 60 (thanks Matt Bell)

0.7.8

server: ability to change motd and maxPlayers
server: fix incorrect playerCount

0.7.7

server: fix crash when client disconnects quickly

0.7.6

onlineModeExceptions are all lowercase now. fixes security hole.

0.7.5

server: add onlineModeExceptions. When server is in:
- online mode: these usernames are exempt from online mode.
- offline mode: these usernames must authenticate.

0.7.4

server: online mode: don't log in client until username verification

0.7.3

revert removing socket delays to reduce latency as it was causing errors and test failures.
server: Client now emits more predictable 'end' events.

0.7.2

fix objectData writer. This fixes sending an 0x17 packet.

0.7.1

remove socket delays to reduce latency. (thanks Matt Bell)

0.7.0

createServer: rename encryption-enabled option to encryption to stay consistent with the examples. (thanks Robin Lambertz)
createClient: don't require both email and username.
- The username and password arguments are used to authenticate with the official minecraft servers and determine the case-correct username. If you have migrated your user account to a mojang login, username looks like an email address.
- If you leave out the password argument, username is used to connect directly to the server. In this case you will get kicked if the server is in online mode.

0.6.7

Emit 'error' event instead of crashing when other computers abuse the minecraft protocol.

Big thanks to Robin Lambertz for this release.

0.6.6

ping: fix calling callback twice when server sends kick
server: send a kick packet when kicking clients. (thanks Robin Lambertz)
ping: include latency property (thanks Jan Buschtöns)

0.6.5

createServer: allow empty options
server: support online mode and encryption (thanks Robin Lambertz)

0.6.4

Allow minecraft username instead of mojang email. (thanks Robin Lambertz)

0.6.3

y values when only 1 byte are always unsigned

0.6.2

0x0e: change face to unsigned byte

0.6.1

0x0d: fix incorrectly swapped stance and y

bored-engineer/node-minecraft-protocol