diff --git a/src/SMAPI/Utilities/CaseInsensitivePathCache.cs b/src/SMAPI.Toolkit/Utilities/CaseInsensitivePathLookup.cs
similarity index 91%
rename from src/SMAPI/Utilities/CaseInsensitivePathCache.cs
rename to src/SMAPI.Toolkit/Utilities/CaseInsensitivePathLookup.cs
index 04fdcfae..2e149e3c 100644
--- a/src/SMAPI/Utilities/CaseInsensitivePathCache.cs
+++ b/src/SMAPI.Toolkit/Utilities/CaseInsensitivePathLookup.cs
@@ -2,10 +2,10 @@ using System;
 using System.Collections.Generic;
 using System.IO;
 
-namespace StardewModdingAPI.Utilities
+namespace StardewModdingAPI.Toolkit.Utilities
 {
     /// <summary>Provides an API for case-insensitive relative path lookups within a root directory.</summary>
-    internal class CaseInsensitivePathCache
+    internal class CaseInsensitivePathLookup
     {
         /*********
         ** Fields
@@ -17,7 +17,7 @@ namespace StardewModdingAPI.Utilities
         private readonly Lazy<Dictionary<string, string>> RelativePathCache;
 
         /// <summary>The case-insensitive path caches by root path.</summary>
-        private static readonly Dictionary<string, CaseInsensitivePathCache> CachesByRootPath = new(StringComparer.OrdinalIgnoreCase);
+        private static readonly Dictionary<string, CaseInsensitivePathLookup> CachedRoots = new(StringComparer.OrdinalIgnoreCase);
 
 
         /*********
@@ -25,7 +25,7 @@ namespace StardewModdingAPI.Utilities
         *********/
         /// <summary>Construct an instance.</summary>
         /// <param name="rootPath">The root directory path for relative paths.</param>
-        public CaseInsensitivePathCache(string rootPath)
+        public CaseInsensitivePathLookup(string rootPath)
         {
             this.RootPath = rootPath;
             this.RelativePathCache = new(this.GetRelativePathCache);
@@ -70,12 +70,12 @@ namespace StardewModdingAPI.Utilities
 
         /// <summary>Get a cached dictionary of relative paths within a root path, for case-insensitive file lookups.</summary>
         /// <param name="rootPath">The root path to scan.</param>
-        public static CaseInsensitivePathCache GetFor(string rootPath)
+        public static CaseInsensitivePathLookup GetCachedFor(string rootPath)
         {
             rootPath = PathUtilities.NormalizePath(rootPath);
 
-            if (!CaseInsensitivePathCache.CachesByRootPath.TryGetValue(rootPath, out CaseInsensitivePathCache? cache))
-                CaseInsensitivePathCache.CachesByRootPath[rootPath] = cache = new CaseInsensitivePathCache(rootPath);
+            if (!CaseInsensitivePathLookup.CachedRoots.TryGetValue(rootPath, out CaseInsensitivePathLookup? cache))
+                CaseInsensitivePathLookup.CachedRoots[rootPath] = cache = new CaseInsensitivePathLookup(rootPath);
 
             return cache;
         }
diff --git a/src/SMAPI/Framework/ContentCoordinator.cs b/src/SMAPI/Framework/ContentCoordinator.cs
index f83d4090..aade7b36 100644
--- a/src/SMAPI/Framework/ContentCoordinator.cs
+++ b/src/SMAPI/Framework/ContentCoordinator.cs
@@ -15,7 +15,7 @@ using StardewModdingAPI.Framework.Utilities;
 using StardewModdingAPI.Internal;
 using StardewModdingAPI.Metadata;
 using StardewModdingAPI.Toolkit.Serialization;
-using StardewModdingAPI.Utilities;
+using StardewModdingAPI.Toolkit.Utilities;
 using StardewValley;
 using StardewValley.GameData;
 using xTile;
@@ -208,7 +208,7 @@ namespace StardewModdingAPI.Framework
                     jsonHelper: this.JsonHelper,
                     onDisposing: this.OnDisposing,
                     aggressiveMemoryOptimizations: this.AggressiveMemoryOptimizations,
-                    relativePathCache: CaseInsensitivePathCache.GetFor(rootDirectory)
+                    relativePathCache: CaseInsensitivePathLookup.GetCachedFor(rootDirectory)
                 );
                 this.ContentManagers.Add(manager);
                 return manager;
diff --git a/src/SMAPI/Framework/ContentManagers/ModContentManager.cs b/src/SMAPI/Framework/ContentManagers/ModContentManager.cs
index f0f4bce9..8f64c5a8 100644
--- a/src/SMAPI/Framework/ContentManagers/ModContentManager.cs
+++ b/src/SMAPI/Framework/ContentManagers/ModContentManager.cs
@@ -9,7 +9,7 @@ using Microsoft.Xna.Framework.Graphics;
 using StardewModdingAPI.Framework.Exceptions;
 using StardewModdingAPI.Framework.Reflection;
 using StardewModdingAPI.Toolkit.Serialization;
-using StardewModdingAPI.Utilities;
+using StardewModdingAPI.Toolkit.Utilities;
 using StardewValley;
 using xTile;
 using xTile.Format;
@@ -33,7 +33,7 @@ namespace StardewModdingAPI.Framework.ContentManagers
         private readonly IContentManager GameContentManager;
 
         /// <summary>A case-insensitive lookup of relative paths within the <see cref="ContentManager.RootDirectory"/>.</summary>
-        private readonly CaseInsensitivePathCache RelativePathCache;
+        private readonly CaseInsensitivePathLookup RelativePathCache;
 
         /// <summary>If a map tilesheet's image source has no file extensions, the file extensions to check for in the local mod folder.</summary>
         private readonly string[] LocalTilesheetExtensions = { ".png", ".xnb" };
@@ -56,7 +56,7 @@ namespace StardewModdingAPI.Framework.ContentManagers
         /// <param name="onDisposing">A callback to invoke when the content manager is being disposed.</param>
         /// <param name="aggressiveMemoryOptimizations">Whether to enable more aggressive memory optimizations.</param>
         /// <param name="relativePathCache">A case-insensitive lookup of relative paths within the <paramref name="rootDirectory"/>.</param>
-        public ModContentManager(string name, IContentManager gameContentManager, IServiceProvider serviceProvider, string modName, string rootDirectory, CultureInfo currentCulture, ContentCoordinator coordinator, IMonitor monitor, Reflector reflection, JsonHelper jsonHelper, Action<BaseContentManager> onDisposing, bool aggressiveMemoryOptimizations, CaseInsensitivePathCache relativePathCache)
+        public ModContentManager(string name, IContentManager gameContentManager, IServiceProvider serviceProvider, string modName, string rootDirectory, CultureInfo currentCulture, ContentCoordinator coordinator, IMonitor monitor, Reflector reflection, JsonHelper jsonHelper, Action<BaseContentManager> onDisposing, bool aggressiveMemoryOptimizations, CaseInsensitivePathLookup relativePathCache)
             : base(name, serviceProvider, rootDirectory, currentCulture, coordinator, monitor, reflection, onDisposing, isNamespaced: true, aggressiveMemoryOptimizations: aggressiveMemoryOptimizations)
         {
             this.GameContentManager = gameContentManager;
diff --git a/src/SMAPI/Framework/ContentPack.cs b/src/SMAPI/Framework/ContentPack.cs
index 2cfd5cce..dde33c95 100644
--- a/src/SMAPI/Framework/ContentPack.cs
+++ b/src/SMAPI/Framework/ContentPack.cs
@@ -2,7 +2,7 @@ using System;
 using System.IO;
 using StardewModdingAPI.Framework.ModHelpers;
 using StardewModdingAPI.Toolkit.Serialization;
-using StardewModdingAPI.Utilities;
+using StardewModdingAPI.Toolkit.Utilities;
 
 namespace StardewModdingAPI.Framework
 {
@@ -16,7 +16,7 @@ namespace StardewModdingAPI.Framework
         private readonly JsonHelper JsonHelper;
 
         /// <summary>A case-insensitive lookup of relative paths within the <see cref="DirectoryPath"/>.</summary>
-        private readonly CaseInsensitivePathCache RelativePathCache;
+        private readonly CaseInsensitivePathLookup RelativePathCache;
 
 
         /*********
@@ -48,7 +48,7 @@ namespace StardewModdingAPI.Framework
         /// <param name="translation">Provides translations stored in the content pack's <c>i18n</c> folder.</param>
         /// <param name="jsonHelper">Encapsulates SMAPI's JSON file parsing.</param>
         /// <param name="relativePathCache">A case-insensitive lookup of relative paths within the <paramref name="directoryPath"/>.</param>
-        public ContentPack(string directoryPath, IManifest manifest, IModContentHelper content, TranslationHelper translation, JsonHelper jsonHelper, CaseInsensitivePathCache relativePathCache)
+        public ContentPack(string directoryPath, IManifest manifest, IModContentHelper content, TranslationHelper translation, JsonHelper jsonHelper, CaseInsensitivePathLookup relativePathCache)
         {
             this.DirectoryPath = directoryPath;
             this.Manifest = manifest;
diff --git a/src/SMAPI/Framework/ModHelpers/ModContentHelper.cs b/src/SMAPI/Framework/ModHelpers/ModContentHelper.cs
index 4a058a48..def0b728 100644
--- a/src/SMAPI/Framework/ModHelpers/ModContentHelper.cs
+++ b/src/SMAPI/Framework/ModHelpers/ModContentHelper.cs
@@ -4,7 +4,7 @@ using StardewModdingAPI.Framework.Content;
 using StardewModdingAPI.Framework.ContentManagers;
 using StardewModdingAPI.Framework.Exceptions;
 using StardewModdingAPI.Framework.Reflection;
-using StardewModdingAPI.Utilities;
+using StardewModdingAPI.Toolkit.Utilities;
 
 namespace StardewModdingAPI.Framework.ModHelpers
 {
@@ -24,7 +24,7 @@ namespace StardewModdingAPI.Framework.ModHelpers
         private readonly string ModName;
 
         /// <summary>A case-insensitive lookup of relative paths within the <see cref="ContentManager.RootDirectory"/>.</summary>
-        private readonly CaseInsensitivePathCache RelativePathCache;
+        private readonly CaseInsensitivePathLookup RelativePathCache;
 
         /// <summary>Simplifies access to private code.</summary>
         private readonly Reflector Reflection;
@@ -41,7 +41,7 @@ namespace StardewModdingAPI.Framework.ModHelpers
         /// <param name="gameContentManager">The game content manager used for map tilesheets not provided by the mod.</param>
         /// <param name="relativePathCache">A case-insensitive lookup of relative paths within the <paramref name="relativePathCache"/>.</param>
         /// <param name="reflection">Simplifies access to private code.</param>
-        public ModContentHelper(ContentCoordinator contentCore, string modFolderPath, IModMetadata mod, string modName, IContentManager gameContentManager, CaseInsensitivePathCache relativePathCache, Reflector reflection)
+        public ModContentHelper(ContentCoordinator contentCore, string modFolderPath, IModMetadata mod, string modName, IContentManager gameContentManager, CaseInsensitivePathLookup relativePathCache, Reflector reflection)
             : base(mod)
         {
             string managedAssetPrefix = contentCore.GetManagedAssetPrefix(mod.Manifest.UniqueID);
diff --git a/src/SMAPI/Framework/ModLoading/ModResolver.cs b/src/SMAPI/Framework/ModLoading/ModResolver.cs
index e3c7873c..4a02e90d 100644
--- a/src/SMAPI/Framework/ModLoading/ModResolver.cs
+++ b/src/SMAPI/Framework/ModLoading/ModResolver.cs
@@ -8,7 +8,7 @@ using StardewModdingAPI.Toolkit.Framework.ModData;
 using StardewModdingAPI.Toolkit.Framework.ModScanning;
 using StardewModdingAPI.Toolkit.Framework.UpdateData;
 using StardewModdingAPI.Toolkit.Serialization.Models;
-using StardewModdingAPI.Utilities;
+using StardewModdingAPI.Toolkit.Utilities;
 
 namespace StardewModdingAPI.Framework.ModLoading
 {
@@ -141,7 +141,7 @@ namespace StardewModdingAPI.Framework.ModLoading
                         }
 
                         // file doesn't exist
-                        string fileName = CaseInsensitivePathCache.GetFor(mod.DirectoryPath).GetFilePath(mod.Manifest.EntryDll!);
+                        string fileName = CaseInsensitivePathLookup.GetCachedFor(mod.DirectoryPath).GetFilePath(mod.Manifest.EntryDll!);
                         if (!File.Exists(Path.Combine(mod.DirectoryPath, fileName)))
                         {
                             mod.SetStatus(ModMetadataStatus.Failed, ModFailReason.InvalidManifest, $"its DLL '{mod.Manifest.EntryDll}' doesn't exist.");
diff --git a/src/SMAPI/Framework/SCore.cs b/src/SMAPI/Framework/SCore.cs
index d2890c29..b3c9087f 100644
--- a/src/SMAPI/Framework/SCore.cs
+++ b/src/SMAPI/Framework/SCore.cs
@@ -1748,7 +1748,7 @@ namespace StardewModdingAPI.Framework
             if (mod.IsContentPack)
             {
                 IMonitor monitor = this.LogManager.GetMonitor(mod.DisplayName);
-                CaseInsensitivePathCache relativePathCache = CaseInsensitivePathCache.GetFor(mod.DirectoryPath);
+                CaseInsensitivePathLookup relativePathCache = CaseInsensitivePathLookup.GetCachedFor(mod.DirectoryPath);
                 GameContentHelper gameContentHelper = new(this.ContentCore, mod, mod.DisplayName, monitor, this.Reflection);
                 IModContentHelper modContentHelper = new ModContentHelper(this.ContentCore, mod.DirectoryPath, mod, mod.DisplayName, gameContentHelper.GetUnderlyingContentManager(), relativePathCache, this.Reflection);
                 TranslationHelper translationHelper = new(mod, contentCore.GetLocale(), contentCore.Language);
@@ -1767,7 +1767,7 @@ namespace StardewModdingAPI.Framework
                 // get mod info
                 string assemblyPath = Path.Combine(
                     mod.DirectoryPath,
-                    CaseInsensitivePathCache.GetFor(mod.DirectoryPath).GetFilePath(manifest.EntryDll!)
+                    CaseInsensitivePathLookup.GetCachedFor(mod.DirectoryPath).GetFilePath(manifest.EntryDll!)
                 );
 
                 // load mod
@@ -1833,7 +1833,7 @@ namespace StardewModdingAPI.Framework
                         {
                             IMonitor packMonitor = this.LogManager.GetMonitor(packManifest.Name);
 
-                            CaseInsensitivePathCache relativePathCache = CaseInsensitivePathCache.GetFor(packDirPath);
+                            CaseInsensitivePathLookup relativePathCache = CaseInsensitivePathLookup.GetCachedFor(packDirPath);
 
                             GameContentHelper gameContentHelper = new(contentCore, mod, packManifest.Name, packMonitor, this.Reflection);
                             IModContentHelper packContentHelper = new ModContentHelper(contentCore, packDirPath, mod, packManifest.Name, gameContentHelper.GetUnderlyingContentManager(), relativePathCache, this.Reflection);
@@ -1847,7 +1847,7 @@ namespace StardewModdingAPI.Framework
 
                         IModEvents events = new ModEvents(mod, this.EventManager);
                         ICommandHelper commandHelper = new CommandHelper(mod, this.CommandManager);
-                        CaseInsensitivePathCache relativePathCache = CaseInsensitivePathCache.GetFor(mod.DirectoryPath);
+                        CaseInsensitivePathLookup relativePathCache = CaseInsensitivePathLookup.GetCachedFor(mod.DirectoryPath);
 #pragma warning disable CS0612 // deprecated code
                         ContentHelper contentHelper = new(contentCore, mod.DirectoryPath, mod, monitor, this.Reflection);
 #pragma warning restore CS0612