1 files changed, 9 insertions, 10 deletions

diff --git a/src/SMAPI/Framework/Networking/ModMessageModel.cs b/src/SMAPI/Framework/Networking/ModMessageModel.cs
index 4f694f9c..01672714 100644
--- a/src/SMAPI/Framework/Networking/ModMessageModel.cs
+++ b/src/SMAPI/Framework/Networking/ModMessageModel.cs
@@ -1,4 +1,5 @@
 using System.Linq;
+using Newtonsoft.Json;
 using Newtonsoft.Json.Linq;
 
 namespace StardewModdingAPI.Framework.Networking
@@ -13,41 +14,39 @@ namespace StardewModdingAPI.Framework.Networking
         ** Origin
         ****/
         /// <summary>The unique ID of the player who broadcast the message.</summary>
-        public long FromPlayerID { get; set; }
+        public long FromPlayerID { get; }
 
         /// <summary>The unique ID of the mod which broadcast the message.</summary>
-        public string FromModID { get; set; }
+        public string FromModID { get; }
 
         /****
         ** Destination
         ****/
         /// <summary>The players who should receive the message.</summary>
-        public long[] ToPlayerIDs { get; set; }
+        public long[]? ToPlayerIDs { get; init; }
 
         /// <summary>The mods which should receive the message, or <c>null</c> for all mods.</summary>
-        public string[] ToModIDs { get; set; }
+        public string[]? ToModIDs { get; }
 
         /// <summary>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.</summary>
-        public string Type { get; set; }
+        public string Type { get; }
 
         /// <summary>The custom mod data being broadcast.</summary>
-        public JToken Data { get; set; }
+        public JToken Data { get; }
 
 
         /*********
         ** Public methods
         *********/
         /// <summary>Construct an instance.</summary>
-        public ModMessageModel() { }
-
-        /// <summary>Construct an instance.</summary>
         /// <param name="fromPlayerID">The unique ID of the player who broadcast the message.</param>
         /// <param name="fromModID">The unique ID of the mod which broadcast the message.</param>
         /// <param name="toPlayerIDs">The players who should receive the message, or <c>null</c> for all players.</param>
         /// <param name="toModIDs">The mods which should receive the message, or <c>null</c> for all mods.</param>
         /// <param name="type">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="data">The custom mod data being broadcast.</param>
-        public ModMessageModel(long fromPlayerID, string fromModID, long[] toPlayerIDs, string[] toModIDs, string type, JToken data)
+        [JsonConstructor]
+        public ModMessageModel(long fromPlayerID, string fromModID, long[]? toPlayerIDs, string[]? toModIDs, string type, JToken data)
         {
             this.FromPlayerID = fromPlayerID;
             this.FromModID = fromModID;