Connecting to Servers

Your primary dealings when connecting to a server will be with the Connection class

Writing Packets

The packet class uses a lot of magic to work, here is how to use them. Look up the particular packet you need to deal with, for this example let’s go with the serverbound.play.KeepAlivePacket

Pay close attention to the definition attribute, and how our class variable corresponds to the name given from the definition:

from minecraft.networking.packets import serverbound
packet = serverbound.play.KeepAlivePacket()
packet.keep_alive_id = random.randint(0, 5000)
connection.write_packet(packet)

and just like that, the packet will be written out to the server.

It is possible to implement your own custom packets by subclassing minecraft.networking.packets.Packet. Read the docstrings and in packets.py and follow the examples in its subpackages for more details on how to do advanced tasks like having a packet that is compatible across multiple protocol versions.

Listening for Certain Packets

Let’s look at how to listen for certain packets, the relevant decorator being

A decorator can be used to register a packet listener:

Example usage:

connection = Connection(options.address, options.port, auth_token=auth_token)
connection.connect()

from minecraft.networking.packets.clientbound.play import ChatMessagePacket

@connection.listener(ChatMessagePacket)
def print_chat(chat_packet):
    print "Position: " + str(chat_packet.position)
    print "Data: " + chat_packet.json_data

Altenatively, packet listeners can also be registered seperate from the function definition.

An example of this can be found in the start.py headless client, it is recreated here:

connection = Connection(options.address, options.port, auth_token=auth_token)
connection.connect()

def print_chat(chat_packet):
    print "Position: " + str(chat_packet.position)
    print "Data: " + chat_packet.json_data

from minecraft.networking.packets.clientbound.play import ChatMessagePacket
connection.register_packet_listener(print_chat, ChatMessagePacket)

The field names position and json_data are inferred by again looking at the definition attribute as before