1 files changed, 39 insertions, 3 deletions

diff --git a/src/SMAPI/Framework/ModHelpers/MultiplayerHelper.cs b/src/SMAPI/Framework/ModHelpers/MultiplayerHelper.cs
index c449a51b..eedad0bc 100644
--- a/src/SMAPI/Framework/ModHelpers/MultiplayerHelper.cs
+++ b/src/SMAPI/Framework/ModHelpers/MultiplayerHelper.cs
@@ -1,4 +1,6 @@
+using System;
 using System.Collections.Generic;
+using StardewModdingAPI.Framework.Networking;
 using StardewValley;
 
 namespace StardewModdingAPI.Framework.ModHelpers
@@ -25,16 +27,50 @@ namespace StardewModdingAPI.Framework.ModHelpers
             this.Multiplayer = multiplayer;
         }
 
+        /// <summary>Get a new multiplayer ID.</summary>
+        public long GetNewID()
+        {
+            return this.Multiplayer.getNewID();
+        }
+
         /// <summary>Get the locations which are being actively synced from the host.</summary>
         public IEnumerable<GameLocation> GetActiveLocations()
         {
             return this.Multiplayer.activeLocations();
         }
 
-        /// <summary>Get a new multiplayer ID.</summary>
-        public long GetNewID()
+        /// <summary>Get a connected player.</summary>
+        /// <param name="id">The player's unique ID.</param>
+        /// <returns>Returns the connected player, or <c>null</c> if no such player is connected.</returns>
+        public IMultiplayerPeer GetConnectedPlayer(long id)
         {
-            return this.Multiplayer.getNewID();
+            return this.Multiplayer.Peers.TryGetValue(id, out MultiplayerPeer peer)
+                ? peer
+                : null;
+        }
+
+        /// <summary>Get all connected players.</summary>
+        public IEnumerable<IMultiplayerPeer> GetConnectedPlayers()
+        {
+            return this.Multiplayer.Peers.Values;
+        }
+
+        /// <summary>Send a message to mods installed by connected players.</summary>
+        /// <typeparam name="TMessage">The data type. This can be a class with a default constructor, or a value type.</typeparam>
+        /// <param name="message">The data to send over the network.</param>
+        /// <param name="messageType">A message type which receiving mods can use to decide whether it's the one they want to handle, like <c>SetPlayerLocation</c>. This doesn't need to be globally unique, since mods should check the originating mod ID.</param>
+        /// <param name="modIDs">The mod IDs which should receive the message on the destination computers, or <c>null</c> for all mods. Specifying mod IDs is recommended to improve performance, unless it's a general-purpose broadcast.</param>
+        /// <param name="playerIDs">The <see cref="Farmer.UniqueMultiplayerID" /> values for the players who should receive the message, or <c>null</c> for all players. If you don't need to broadcast to all players, specifying player IDs is recommended to reduce latency.</param>
+        /// <exception cref="ArgumentNullException">The <paramref name="message"/> or <paramref name="messageType" /> is null.</exception>
+        public void SendMessage<TMessage>(TMessage message, string messageType, string[] modIDs = null, long[] playerIDs = null)
+        {
+            this.Multiplayer.BroadcastModMessage(
+                message: message,
+                messageType: messageType,
+                fromModID: this.ModID,
+                toModIDs: modIDs,
+                toPlayerIDs: playerIDs
+            );
         }
     }
 }