diff --git a/ClaimLink/ClaimLink.cs b/ClaimLink/ClaimLink.cs
new file mode 100644
index 0000000..cbf4aeb
--- /dev/null
+++ b/ClaimLink/ClaimLink.cs
@@ -0,0 +1,10 @@
+using ProtoBuf;
+
+namespace ClaimLink;
+
+[ProtoContract]
+public class ClaimLink
+{
+    [ProtoMember(1)]
+    public int GroupId;
+}
diff --git a/ClaimLink/ClaimLink.csproj b/ClaimLink/ClaimLink.csproj
index f22b882..ae0fee9 100644
--- a/ClaimLink/ClaimLink.csproj
+++ b/ClaimLink/ClaimLink.csproj
@@ -16,6 +16,10 @@
        <HintPath>$(COMMANDHOOK)/CommandHook.dll</HintPath>
        <Private>false</Private>
     </Reference>
+    <Reference Include="protobuf-net">
+       <HintPath>$(VINTAGE_STORY)/Lib/protobuf-net.dll</HintPath>
+       <Private>false</Private>
+    </Reference>
   </ItemGroup>
 
 <ItemGroup>
diff --git a/ClaimLink/ClaimLinkModSystem.cs b/ClaimLink/ClaimLinkModSystem.cs
index 90850e8..5f47ea8 100644
--- a/ClaimLink/ClaimLinkModSystem.cs
+++ b/ClaimLink/ClaimLinkModSystem.cs
@@ -6,8 +6,9 @@ namespace ClaimLink;
 
 public class ClaimLinkModSystem : ModSystem
 {
-    internal static ILandClaimAPI LandClaimAPI;
-    internal static ILogger Logger;
+    internal static ILandClaimAPI LandClaimAPI = null!;
+    internal static ILogger Logger = null!;
+    internal static ClaimLinkRegistry Registry = null!;
     internal ClaimLinkCommandListener? cmdListener;
 
     public override bool ShouldLoad(EnumAppSide forSide) => forSide == EnumAppSide.Server;
@@ -16,6 +17,7 @@ public class ClaimLinkModSystem : ModSystem
     {
         LandClaimAPI = api.World.Claims;
         Logger = api.Logger;
+        Registry = new ClaimLinkRegistry(api.WorldManager.SaveGame);
 
         cmdListener = new ClaimLinkCommandListener();
         CommandHookModSystem.Register(cmdListener);
diff --git a/ClaimLink/ClaimLinkRegistry.cs b/ClaimLink/ClaimLinkRegistry.cs
new file mode 100644
index 0000000..09dec59
--- /dev/null
+++ b/ClaimLink/ClaimLinkRegistry.cs
@@ -0,0 +1,51 @@
+using System.Collections.Generic;
+using ProtoBuf;
+using Vintagestory.API.Server;
+
+namespace ClaimLink;
+
+[ProtoContract]
+public class ClaimLinkData
+{
+    [ProtoMember(1)]
+    public List<ClaimLink> Links = new();
+}
+
+public class ClaimLinkRegistry
+{
+    private const string SaveKey = "claimlink:links";
+
+    private readonly ISaveGame saveGame;
+    private readonly Dictionary<int, ClaimLink> byGroupId = new();
+
+    public ClaimLinkRegistry(ISaveGame saveGame)
+    {
+        this.saveGame = saveGame;
+
+        ClaimLinkData? data = saveGame.GetData<ClaimLinkData?>(SaveKey, null);
+        if (data == null)
+            return;
+
+        foreach (ClaimLink link in data.Links)
+            byGroupId[link.GroupId] = link;
+    }
+
+    public ClaimLink? Get(int groupId) => byGroupId.TryGetValue(groupId, out ClaimLink? link) ? link : null;
+
+    public void Add(ClaimLink link)
+    {
+        byGroupId[link.GroupId] = link;
+        Save();
+    }
+
+    public void Remove(int groupId)
+    {
+        byGroupId.Remove(groupId);
+        Save();
+    }
+
+    private void Save()
+    {
+        saveGame.StoreData(SaveKey, new ClaimLinkData { Links = new List<ClaimLink>(byGroupId.Values) });
+    }
+}
diff --git a/ClaimLink/LandCommandListener.cs b/ClaimLink/LandCommandListener.cs
index 3faab54..df40a9e 100644
--- a/ClaimLink/LandCommandListener.cs
+++ b/ClaimLink/LandCommandListener.cs
@@ -55,7 +55,7 @@ public class ClaimLinkCommandListener : ICommandHookListener
         {
             string word = rawArgs.PeekWord();
 
-            if (topLevel.TryGetValue(word, out SubHandler handler))
+            if (topLevel.TryGetValue(word, out SubHandler? handler))
             {
                 rawArgs.PopWord();
                 handler(args.Caller, rawArgs);
@@ -77,7 +77,7 @@ public class ClaimLinkCommandListener : ICommandHookListener
     {
         string word = args.PeekWord();
 
-        if (claimSub.TryGetValue(word, out SubHandler handler))
+        if (claimSub.TryGetValue(word, out SubHandler? handler))
         {
             args.PopWord();
             handler(caller, args);