i guess it's working

src/Server.cpp

@@ -0,0 +1,44 @@
+#include "Server.h"
+
+#include "Lobby.h"
+#include "NetworkInterface.h"
+#include <godot_cpp/classes/engine.hpp>
+
+using namespace godot;
+
+namespace blitz {
+
+void Server::_bind_methods() {}
+
+Server::Server() {}
+
+Server::~Server() {}
+
+void Server::_ready() {
+	if (Engine::get_singleton()->is_editor_hint())
+		return;
+
+
+	m_Lobby = Object::cast_to<Lobby>(get_parent());
+	DEV_ASSERT(m_Lobby);
+	m_NetworkInterface = Object::cast_to<NetworkInterface>(m_Lobby->find_child("NetworkInterface"));
+	DEV_ASSERT(m_NetworkInterface);
+
+	m_Lobby->connect("player_connected", callable_mp(this, &Server::OnPlayerConnect));
+	m_Lobby->connect("player_disconnected", callable_mp(this, &Server::OnPlayerDisconnect));
+}
+
+void Server::OnPlayerConnect(uint64_t a_PeerId) {
+	for (int i = 0; i < m_Peers.size(); i++) {
+		m_NetworkInterface->rpc_id(a_PeerId, "AddPlayer", m_Peers[i], "Aucuneidee");
+	}
+	m_Peers.push_back(a_PeerId);
+	m_NetworkInterface->rpc("AddPlayer", a_PeerId, "Aucuneidee");
+}
+
+void Server::OnPlayerDisconnect(uint64_t a_PeerId) {
+	m_Peers.erase(a_PeerId);
+	m_NetworkInterface->rpc("RemovePlayer", a_PeerId);
+}
+
+}  // namespace blitz