Attention: Here be dragons

This is the latest (unstable) version of this documentation, which may document features not available in or compatible with released stable versions of Godot.

Checking the stable version of the documentation...

MultiplayerAPIExtension

Inherits: MultiplayerAPI < RefCounted < Object

Base class used for extending the MultiplayerAPI.

Description

This class can be used to augment or replace the default MultiplayerAPI implementation via script or extensions.

The following example augment the default implementation (SceneMultiplayer) by logging every RPC being made, and every object being configured for replication.

GDScript

extends MultiplayerAPIExtension
class_name LogMultiplayer

# We want to augment the default SceneMultiplayer.
var base_multiplayer = SceneMultiplayer.new()

func _init():
    # Just passthrough base signals (copied to var to avoid cyclic reference)
    var cts = connected_to_server
    var cf = connection_failed
    var pc = peer_connected
    var pd = peer_disconnected
    base_multiplayer.connected_to_server.connect(func(): cts.emit())
    base_multiplayer.connection_failed.connect(func(): cf.emit())
    base_multiplayer.peer_connected.connect(func(id): pc.emit(id))
    base_multiplayer.peer_disconnected.connect(func(id): pd.emit(id))

func _poll():
    return base_multiplayer.poll()

# Log RPC being made and forward it to the default multiplayer.
func _rpc(peer: int, object: Object, method: StringName, args: Array) -> Error:
    print("Got RPC for %d: %s::%s(%s)" % [peer, object, method, args])
    return base_multiplayer.rpc(peer, object, method, args)

# Log configuration add. E.g. root path (nullptr, NodePath), replication (Node, Spawner|Synchronizer), custom.
func _object_configuration_add(object, config: Variant) -> Error:
    if config is MultiplayerSynchronizer:
        print("Adding synchronization configuration for %s. Synchronizer: %s" % [object, config])
    elif config is MultiplayerSpawner:
        print("Adding node %s to the spawn list. Spawner: %s" % [object, config])
    return base_multiplayer.object_configuration_add(object, config)

# Log configuration remove. E.g. root path (nullptr, NodePath), replication (Node, Spawner|Synchronizer), custom.
func _object_configuration_remove(object, config: Variant) -> Error:
    if config is MultiplayerSynchronizer:
        print("Removing synchronization configuration for %s. Synchronizer: %s" % [object, config])
    elif config is MultiplayerSpawner:
        print("Removing node %s from the spawn list. Spawner: %s" % [object, config])
    return base_multiplayer.object_configuration_remove(object, config)

# These can be optional, but in our case we want to augment SceneMultiplayer, so forward everything.
func _set_multiplayer_peer(p_peer: MultiplayerPeer):
    base_multiplayer.multiplayer_peer = p_peer

func _get_multiplayer_peer() -> MultiplayerPeer:
    return base_multiplayer.multiplayer_peer

func _get_unique_id() -> int:
    return base_multiplayer.get_unique_id()

func _get_peer_ids() -> PackedInt32Array:
    return base_multiplayer.