Godot Networking — Quick Reference

Last verified: 2026-02-12 | Engine: Godot 4.6

What Changed Since ~4.3 (LLM Cutoff)

4.6 Changes

• Networking section in breaking changes: See the official migration guide for specifics at the 4.5→4.6 level

4.5 Changes

• No major networking API breaks — core multiplayer API remains stable

Current API Patterns

High-Level Multiplayer

# Server
func host_game(port: int = 9999) -> void:
    var peer := ENetMultiplayerPeer.new()
    peer.create_server(port)
    multiplayer.multiplayer_peer = peer
    multiplayer.peer_connected.connect(_on_peer_connected)
    multiplayer.peer_disconnected.connect(_on_peer_disconnected)

# Client
func join_game(address: String, port: int = 9999) -> void:
    var peer := ENetMultiplayerPeer.new()
    peer.create_client(address, port)
    multiplayer.multiplayer_peer = peer

RPCs

# Server-authoritative pattern
@rpc("any_peer", "call_local", "reliable")
func request_action(action_data: Dictionary) -> void:
    if not multiplayer.is_server():
        return
    # Validate on server, then broadcast
    _execute_action.rpc(action_data)

@rpc("authority", "call_local", "reliable")
func _execute_action(action_data: Dictionary) -> void:
    # All peers execute the validated action
    pass

MultiplayerSpawner and MultiplayerSynchronizer

# Use MultiplayerSpawner for automatic node replication
# Use MultiplayerSynchronizer for property synchronization

# MultiplayerSynchronizer setup:
# 1. Add as child of the node to sync
# 2. Configure replication properties in editor
# 3. Set visibility filters for relevancy

SceneMultiplayer Configuration

func _ready() -> void:
    var scene_mp := multiplayer as SceneMultiplayer
    scene_mp.auth_callback = _authenticate_peer
    scene_mp.server_relay = false  # Direct peer connections

func _authenticate_peer(id: int, data: PackedByteArray) -> void:
    # Custom authentication logic
    pass

Common Mistakes

• Not using "any_peer" for client-to-server RPCs (defaults to authority only)
• Trusting client data without server-side validation
• Using "unreliable" for game state changes (use for position updates only)
• Not setting multiplayer authority (set_multiplayer_authority()) on spawned nodes