High-level multiplayer API interface. Base class for high-level multiplayer API implementations. See also [MultiplayerPeer]. By default, [SceneTree] has a reference to an implementation of this class and uses it to provide multiplayer capabilities (i.e. RPCs) across the whole scene. It is possible to override the MultiplayerAPI instance used by specific tree branches by calling the [method SceneTree.set_multiplayer] method, effectively allowing to run both client and server in the same scene. It is also possible to extend or replace the default implementation via scripting or native extensions. See [MultiplayerAPIExtension] for details about extensions, [SceneMultiplayer] for the details about the default implementation. Returns a new instance of the default MultiplayerAPI. Returns the default MultiplayerAPI implementation class name. This is usually [code]"SceneMultiplayer"[/code] when [SceneMultiplayer] is available. See [method set_default_interface]. Returns the peer IDs of all connected peers of this MultiplayerAPI's [member multiplayer_peer]. Returns the sender's peer ID for the RPC currently being executed. [b]Note:[/b] If not inside an RPC this method will return 0. Returns the unique peer ID of this MultiplayerAPI's [member multiplayer_peer]. Returns [code]true[/code] if there is a [member multiplayer_peer] set. Returns [code]true[/code] if this MultiplayerAPI's [member multiplayer_peer] is valid and in server mode (listening for connections). Notifies the MultiplayerAPI of a new [param configuration] for the given [param object]. This method is used internally by [SceneTree] to configure the root path for this MultiplayerAPI (passing [code]null[/code] and a valid [NodePath] as [param configuration]). This method can be further used by MultiplayerAPI implementations to provide additional features, refer to specific implementation (e.g. [SceneMultiplayer]) for details on how they use it. [b]Note:[/b] This method is mostly relevant when extending or overriding the MultiplayerAPI behavior via [MultiplayerAPIExtension]. Notifies the MultiplayerAPI to remove a [param configuration] for the given [param object]. This method is used internally by [SceneTree] to configure the root path for this MultiplayerAPI (passing [code]null[/code] and an empty [NodePath] as [param configuration]). This method can be further used by MultiplayerAPI implementations to provide additional features, refer to specific implementation (e.g. [SceneMultiplayer]) for details on how they use it. [b]Note:[/b] This method is mostly relevant when extending or overriding the MultiplayerAPI behavior via [MultiplayerAPIExtension]. Method used for polling the MultiplayerAPI. You only need to worry about this if you set [member SceneTree.multiplayer_poll] to [code]false[/code]. By default, [SceneTree] will poll its MultiplayerAPI(s) for you. [b]Note:[/b] This method results in RPCs being called, so they will be executed in the same context of this function (e.g. [code]_process[/code], [code]physics[/code], [Thread]). Sends an RPC to the target [param peer]. The given [param method] will be called on the remote [param object] with the provided [param arguments]. The RPC may also be called locally depending on the implementation and RPC configuration. See [method Node.rpc] and [method Node.rpc_config]. [b]Note:[/b] Prefer using [method Node.rpc], [method Node.rpc_id], or [code]my_method.rpc(peer, arg1, arg2, ...)[/code] (in GDScript), since they are faster. This method is mostly useful in conjunction with [MultiplayerAPIExtension] when augmenting or replacing the multiplayer capabilities. Sets the default MultiplayerAPI implementation class. This method can be used by modules and extensions to configure which implementation will be used by [SceneTree] when the engine starts. The peer object to handle the RPC system (effectively enabling networking when set). Depending on the peer itself, the MultiplayerAPI will become a network server (check with [method is_server]) and will set root node's network mode to authority, or it will become a regular client peer. All child nodes are set to inherit the network mode by default. Handling of networking-related events (connection, disconnection, new clients) is done by connecting to MultiplayerAPI's signals. Emitted when this MultiplayerAPI's [member multiplayer_peer] successfully connected to a server. Only emitted on clients. Emitted when this MultiplayerAPI's [member multiplayer_peer] fails to establish a connection to a server. Only emitted on clients. Emitted when this MultiplayerAPI's [member multiplayer_peer] connects with a new peer. ID is the peer ID of the new peer. Clients get notified when other clients connect to the same server. Upon connecting to a server, a client also receives this signal for the server (with ID being 1). Emitted when this MultiplayerAPI's [member multiplayer_peer] disconnects from a peer. Clients get notified when other clients disconnect from the same server. Emitted when this MultiplayerAPI's [member multiplayer_peer] disconnects from server. Only emitted on clients. Used with [method Node.rpc_config] to disable a method or property for all RPC calls, making it unavailable. Default for all methods. Used with [method Node.rpc_config] to set a method to be callable remotely by any peer. Analogous to the [code]@rpc(any)[/code] annotation. Calls are accepted from all remote peers, no matter if they are node's authority or not. Used with [method Node.rpc_config] to set a method to be callable remotely only by the current multiplayer authority (which is the server by default). Analogous to the [code]@rpc(authority)[/code] annotation. See [method Node.set_multiplayer_authority].