my attempt

Barotrauma/BarotraumaServer/ServerSource/Networking/ChatMessage.cs

@@ -1,6 +1,7 @@
 using Microsoft.Xna.Framework;
 using System;
 using System.Text;
+using MoonSharp.Interpreter;
 
 namespace Barotrauma.Networking
 {
@@ -169,6 +170,11 @@ namespace Barotrauma.Networking
             {
                 GameMain.Server.SendChatMessage(txt, null, c);
             }
+
+
+            GameMain.Lua.hook.Call("chatMessage", new DynValue[] { DynValue.NewString(txt), UserData.Create(c) });
+
+
         }
 
         public int EstimateLengthBytesServer(Client c)

Barotrauma/BarotraumaServer/ServerSource/Networking/GameServer.cs

@@ -308,6 +308,9 @@ namespace Barotrauma.Networking
                 SendConsoleMessage("Granted all permissions to " + newClient.Name + ".", newClient);
             }
 
+            GameMain.Lua.hook.Call("clientConnected", new MoonSharp.Interpreter.DynValue[] { MoonSharp.Interpreter.UserData.Create(newClient) });
+            
+
             SendChatMessage($"ServerMessage.JoinedServer~[client]={clName}", ChatMessageType.Server, null, changeType: PlayerConnectionChangeType.Joined);
             serverSettings.ServerDetailsChanged = true;
 
@@ -2346,6 +2349,9 @@ namespace Barotrauma.Networking
 
             Log("Round started.", ServerLog.MessageType.ServerMessage);
 
+            GameMain.Lua.hook.Call("roundStart", new MoonSharp.Interpreter.DynValue[] { });
+
+
             gameStarted = true;
             initiatedStartGame = false;
             GameMain.ResetFrameTime();
@@ -2461,6 +2467,9 @@ namespace Barotrauma.Networking
                 Log("Ending the round...", ServerLog.MessageType.ServerMessage);
             }
 
+            GameMain.Lua.hook.Call("roundEnd", new MoonSharp.Interpreter.DynValue[] { });
+
+
             string endMessage = TextManager.FormatServerMessage("RoundSummaryRoundHasEnded");
             var traitorResults = TraitorManager?.GetEndResults() ?? new List<TraitorMissionResult>();
 
@@ -2713,6 +2722,8 @@ namespace Barotrauma.Networking
         {
             if (client == null) return;
 
+            GameMain.Lua.hook.Call("clientDisconnected", new MoonSharp.Interpreter.DynValue[] { MoonSharp.Interpreter.UserData.Create(client) });
+
             if (gameStarted && client.Character != null)
             {
                 client.Character.ClientDisconnected = true;