Renamed BattleActionPacket -> CommandResultPacket as it better defines what these packets do. A command fires -> here is what happened due to it.

FFXIVClassic Map Server/packets/send/Actor/battle/CommandResultX01Packet.cs

@@ -0,0 +1,52 @@
+using FFXIVClassic.Common;
+using System;
+using System.IO;
+
+namespace FFXIVClassic_Map_Server.packets.send.actor.battle
+{
+    // see xtx_command
+    enum CommandResultX01PacketCommand : ushort
+    {
+        Disengage = 12002,
+        Attack = 22104,
+    }
+
+    class CommandResultX01Packet
+    {
+        public const ushort OPCODE = 0x0139;
+        public const uint PACKET_SIZE = 0x58;
+
+        public static SubPacket BuildPacket(uint sourceActorId, uint animationId, ushort commandId, CommandResult action)
+        {
+            byte[] data = new byte[PACKET_SIZE - 0x20];
+
+            using (MemoryStream mem = new MemoryStream(data))
+            {
+                using (BinaryWriter binWriter = new BinaryWriter(mem))
+                {
+                    binWriter.Write((UInt32)sourceActorId);
+
+                    binWriter.Write((UInt32)animationId);
+
+                    //Missing... last value is float, string in here as well?
+
+                    binWriter.Seek(0x20, SeekOrigin.Begin);
+                    binWriter.Write((UInt32)1); //Num actions (always 1 for this)
+                    binWriter.Write((UInt16)commandId);
+                    binWriter.Write((UInt16)0x801); //?
+
+                    binWriter.Write((UInt32)action.targetId);
+
+                    binWriter.Write((UInt16)action.amount);
+                    binWriter.Write((UInt16)action.worldMasterTextId);
+
+                    binWriter.Write((UInt32)action.effectId);
+                    binWriter.Write((Byte)action.param);
+                    binWriter.Write((Byte)1); //?
+                }
+            }
+
+            return new SubPacket(OPCODE, sourceActorId, data);
+        }
+    }
+}