Hotpatch for map loading test fail.

Co-authored-by: kaylie <moony@hellomouse.net>

Directory.Packages.props

@@ -59,7 +59,7 @@
     <PackageVersion Include="SixLabors.ImageSharp" Version="3.1.12" />
     <PackageVersion Include="SpaceWizards.HttpListener" Version="0.2.0" />
     <PackageVersion Include="SpaceWizards.NFluidsynth" Version="0.2.2" />
-    <PackageVersion Include="SpaceWizards.Sdl" Version="1.0.0" />
+    <PackageVersion Include="SpaceWizards.Sdl" Version="1.1.1" />
     <PackageVersion Include="SpaceWizards.SharpFont" Version="1.1.0" />
     <PackageVersion Include="SpaceWizards.Sodium" Version="0.3.0" />
     <PackageVersion Include="SpaceWizards.Fontconfig.Interop" Version="1.0.0" />

Imports/WebView.props

@@ -1,4 +1,13 @@
-<Project>
+<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <!-- If you are using Robust.Client.WebView, import this to depend on it. -->
+
+  <Import Condition="'$(_RTMacOSAppBundle_targets_imported)' != 'True'"
+          Project="$(MSBuildThisFileDirectory)\..\MSBuild\MacOSAppBundle.targets" />
+
+  <PropertyGroup>
+    <_RTMacOSAppBundle_for_webview>--webview</_RTMacOSAppBundle_for_webview>
+  </PropertyGroup>
+
   <ItemGroup>
     <ProjectReference Include="$(MSBuildThisFileDirectory)\..\Robust.Client.WebView\Robust.Client.WebView.csproj" />
   </ItemGroup>

MSBuild/MacOSAppBundle.targets

@@ -0,0 +1,24 @@
+<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <!--
+  Depend on this in your client project (e.g. Content.Client) to generate a development app bundle for macOS.
+  This is required for WebView.
+  -->
+
+  <PropertyGroup>
+    <RTMakeAppBundle Condition="'$(TargetOS)' == 'MacOS' And '$(RTMakeAppBundle)' == '' And '$(FullRelease)' != 'True'">True</RTMakeAppBundle>
+    <RTAppBundleName Condition="'$(RTAppBundleName)' == ''">RobustToolbox Project</RTAppBundleName>
+    <RTAppBundleIdentifier Condition="'$(RTAppBundleIdentifier)' == ''">org.robusttoolbox.project</RTAppBundleIdentifier>
+    <!-- RTAppBundleIcon controls icon -->
+  </PropertyGroup>
+
+  <PropertyGroup>
+    <_RTMacOSAppBundle_targets_imported>True</_RTMacOSAppBundle_targets_imported>
+  </PropertyGroup>
+
+  <Target Name="RTMakeAppBundleAfterBuild" Condition="'$(RTMakeAppBundle)' == 'True'" AfterTargets="AfterBuild">
+    <PropertyGroup>
+      <_RTMacOSAppBundle_icon Condition="'$(RTAppBundleIcon)' != ''">--icon &quot;$(RTAppBundleIcon)&quot;</_RTMacOSAppBundle_icon>
+    </PropertyGroup>
+    <Exec Command="$(MSBuildThisFileDirectory)/../Tools/macos_make_appbundle.py $(_RTMacOSAppBundle_for_webview) --name &quot;$(RTAppBundleName)&quot; --directory &quot;$(OutputPath)&quot; --apphost &quot;$(AssemblyName)&quot; --identifier &quot;$(RTAppBundleIdentifier)&quot; $(_RTMacOSAppBundle_icon)" />
+  </Target>
+</Project>

MSBuild/Robust.Engine.Version.props

@@ -1,4 +1,4 @@
 <Project>
 
-    <!-- This file automatically reset by Tools/version.py -->
+    <!-- This file automatically reset by Tools/version.py -->
 

MSBuild/Robust.ProjectReferences.targets

@@ -11,7 +11,7 @@
   <Target Name="_RTCheckForDirectReferences" BeforeTargets="BeforeResolveReferences"
           Condition="'$(AllowDirectRobustReferences)' != 'true'">
     <Error File="%(ProjectReference.DefiningProjectFullPath)"
-           Text="Content may not reference %(Filename) directly"
+           Text="Direct reference to %(Filename) is not allowed. Use RobustToolbox/Imports/*.props instead (e.g., Shared.props, Client.props, Server.props)"
            Condition="$([System.Text.RegularExpressions.Regex]::IsMatch('%(Identity)', 'RobustToolbox')) and !$([System.Text.RegularExpressions.Regex]::IsMatch('%(DefiningProjectFullPath)', '([Mm]icrosoft|RobustToolbox)'))" />
   </Target>
 </Project>

Resources/Locale/en-US/replays.ftl

@@ -9,6 +9,9 @@ cmd-replay-pause-help = replay_pause
 cmd-replay-toggle-desc = Resume or pause replay playback.
 cmd-replay-toggle-help = replay_toggle
 
+cmd-replay-toggle-screenshot-mode-desc = Toggles screenshot mode for replays, hiding the replay control widget.
+cmd-replay-toggle-screenshot-mode-help = replay_toggle_screenshot_mode
+
 cmd-replay-stop-desc = Stop and unload a replay.
 cmd-replay-stop-help = replay_stop
 

Robust.Analyzers/ValidateMemberAnalyzer.cs

@@ -1,8 +1,6 @@
 #nullable enable
 using System.Collections.Immutable;
 using Microsoft.CodeAnalysis;
-using Microsoft.CodeAnalysis.CSharp;
-using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Microsoft.CodeAnalysis.Diagnostics;
 using Microsoft.CodeAnalysis.Operations;
 using Robust.Roslyn.Shared;
@@ -29,16 +27,15 @@ public sealed class ValidateMemberAnalyzer : DiagnosticAnalyzer
     {
         context.EnableConcurrentExecution();
         context.ConfigureGeneratedCodeAnalysis(GeneratedCodeAnalysisFlags.Analyze | GeneratedCodeAnalysisFlags.ReportDiagnostics);
-        context.RegisterSyntaxNodeAction(AnalyzeExpression, SyntaxKind.InvocationExpression);
+        context.RegisterOperationAction(AnalyzeOperation, OperationKind.Invocation);
     }
 
-    private void AnalyzeExpression(SyntaxNodeAnalysisContext context)
+    private void AnalyzeOperation(OperationAnalysisContext context)
     {
-        if (context.Node is not InvocationExpressionSyntax node)
+        if (context.Operation is not IInvocationOperation node)
             return;
 
-        if (context.SemanticModel.GetSymbolInfo(node.Expression).Symbol is not IMethodSymbol methodSymbol)
-            return;
+        var methodSymbol = node.TargetMethod;
 
         // We need at least one type argument for context
         if (methodSymbol.TypeArguments.Length < 1)
@@ -48,16 +45,12 @@ public sealed class ValidateMemberAnalyzer : DiagnosticAnalyzer
         if (methodSymbol.TypeArguments[0] is not INamedTypeSymbol targetType)
             return;
 
-        // We defer building this set until we need it later, so we don't have to build it for every single method invocation!
-        ImmutableHashSet<ISymbol>? members = null;
-
         // Check each parameter of the method
-        foreach (var parameterContext in node.ArgumentList.Arguments)
+        foreach (var op in node.Arguments)
         {
-
-            // Get the symbol for this parameter
-            if (context.SemanticModel.GetOperation(parameterContext) is not IArgumentOperation op || op.Parameter is null)
+            if (op.Parameter is null)
                 continue;
+
             var parameterSymbol = op.Parameter.OriginalDefinition;
 
             // Make sure the parameter has the ValidateMember attribute
@@ -66,15 +59,12 @@ public sealed class ValidateMemberAnalyzer : DiagnosticAnalyzer
 
             // Find the value passed for this parameter.
             // We use GetConstantValue to resolve compile-time values - i.e. the result of nameof()
-            if (context.SemanticModel.GetConstantValue(parameterContext.Expression).Value is not string fieldName)
+            if (op.Value.ConstantValue is not { HasValue: true, Value: string fieldName})
                 continue;
 
-            // Get a set containing all the members of the target type and its ancestors
-            members ??= targetType.GetBaseTypesAndThis().SelectMany(n => n.GetMembers()).ToImmutableHashSet(SymbolEqualityComparer.Default);
-
             // Check each member of the target type to see if it matches our passed in value
             var found = false;
-            foreach (var member in members)
+            foreach (var member in targetType.GetMembers())
             {
                 if (member.Name == fieldName)
                 {
@@ -84,12 +74,14 @@ public sealed class ValidateMemberAnalyzer : DiagnosticAnalyzer
             }
             // If we didn't find it, report the violation
             if (!found)
+            {
                 context.ReportDiagnostic(Diagnostic.Create(
                     ValidateMemberDescriptor,
-                    parameterContext.GetLocation(),
+                    op.Syntax.GetLocation(),
                     fieldName,
                     targetType.Name
-                    ));
+                ));
+            }
         }
     }
 }

Robust.Benchmarks/Robust.Benchmarks.csproj

@@ -16,7 +16,11 @@
     <ProjectReference Include="..\Robust.UnitTesting\Robust.UnitTesting.csproj" />
   </ItemGroup>
   <ItemGroup>
-    <PackageReference Include="BenchmarkDotNet" />
+    <!-- BenchmarkDotNet autogenerates files that attempt to reference BenchmarkDotNet through Robust.Benchmarks.
+     By default the RT project privates these files, so we have to explicitly state that these files should be made available
+     to the BenchmarkDotNet project so it can build the runner that executes the benchmark. -->
+    <PackageReference Include="BenchmarkDotNet" PrivateAssets="none" />
+
     <PackageReference Include="JetBrains.Annotations" />
     <PackageReference Include="YamlDotNet" />
     <PackageReference Include="prometheus-net" />

Robust.Client.WebView/Cef/Program.cs

@@ -1,7 +1,9 @@
 using System;
 using System.Diagnostics;
 using System.Globalization;
+using System.Runtime.InteropServices;
 using System.Threading;
+using Robust.Shared.ContentPack;
 using Xilium.CefGlue;
 
 namespace Robust.Client.WebView.Cef
@@ -20,6 +22,20 @@ namespace Robust.Client.WebView.Cef
                 argv[0] = "-";
             }
 
+#if MACOS
+            NativeLibrary.SetDllImportResolver(typeof(CefSettings).Assembly,
+                (name, assembly, path) =>
+                {
+                    if (name == "libcef")
+                    {
+                        var libPath = PathHelpers.ExecutableRelativeFile("../../../../Frameworks/Chromium Embedded Framework.framework/Chromium Embedded Framework");
+                        return NativeLibrary.Load(libPath, assembly, path);
+                    }
+
+                    return 0;
+                });
+#endif
+
             var mainArgs = new CefMainArgs(argv);
 
             StartWatchThread();

Robust.Client.WebView/Cef/RobustCefApp.cs

@@ -41,7 +41,7 @@ namespace Robust.Client.WebView.Cef
             // commandLine.AppendSwitch("--single-process");
 
             //commandLine.AppendSwitch("--disable-gpu");
-            commandLine.AppendSwitch("--disable-gpu-compositing");
+            //commandLine.AppendSwitch("--disable-gpu-compositing");
             //commandLine.AppendSwitch("--in-process-gpu");
 
             commandLine.AppendSwitch("--off-screen-rendering-enabled");
@@ -54,6 +54,7 @@ namespace Robust.Client.WebView.Cef
 
         protected override void OnRegisterCustomSchemes(CefSchemeRegistrar registrar)
         {
+            // NOTE: KEEP IN SYNC WITH RUST CODE!
             registrar.AddCustomScheme("res", CefSchemeOptions.Secure | CefSchemeOptions.Standard);
             registrar.AddCustomScheme("usr", CefSchemeOptions.Secure | CefSchemeOptions.Standard);
         }

Robust.Client.WebView/Cef/WebViewManagerCef.Control.cs

@@ -17,11 +17,13 @@ namespace Robust.Client.WebView.Cef
 {
     internal partial class WebViewManagerCef
     {
+        private readonly List<ControlImpl> _activeControls = new();
+
         public IWebViewControlImpl MakeControlImpl(WebViewControl owner)
         {
             var shader = _prototypeManager.Index<ShaderPrototype>("bgra");
             var shaderInstance = shader.Instance();
-            var impl =  new ControlImpl(owner, shaderInstance);
+            var impl =  new ControlImpl(this, owner, shaderInstance);
             _dependencyCollection.InjectDependencies(impl);
             return impl;
         }
@@ -133,11 +135,13 @@ namespace Robust.Client.WebView.Cef
             [Dependency] private readonly IClyde _clyde = default!;
             [Dependency] private readonly IInputManager _inputMgr = default!;
 
+            private readonly WebViewManagerCef _manager;
             public readonly WebViewControl Owner;
             private readonly ShaderInstance _shaderInstance;
 
-            public ControlImpl(WebViewControl owner, ShaderInstance shaderInstance)
+            public ControlImpl(WebViewManagerCef manager, WebViewControl owner, ShaderInstance shaderInstance)
             {
+                _manager = manager;
                 Owner = owner;
                 _shaderInstance = shaderInstance;
             }
@@ -194,6 +198,7 @@ namespace Robust.Client.WebView.Cef
                 var texture = _clyde.CreateBlankTexture<Rgba32>(Vector2i.One);
 
                 _data = new LiveData(texture, client, browser, renderer);
+                _manager._activeControls.Add(this);
             }
 
             public void CloseBrowser()
@@ -203,6 +208,8 @@ namespace Robust.Client.WebView.Cef
                 _data!.Texture.Dispose();
                 _data.Browser.GetHost().CloseBrowser(true);
                 _data = null;
+
+                _manager._activeControls.Remove(this);
             }
 
             public void MouseMove(GUIMouseMoveEventArgs args)
@@ -279,6 +286,7 @@ namespace Robust.Client.WebView.Cef
 
                     // Logger.Debug($"{guiRawEvent.Action} {guiRawEvent.Key} {guiRawEvent.ScanCode} {vkKey}");
 
+#if !MACOS
                     var lParam = 0;
                     lParam |= (guiRawEvent.ScanCode & 0xFF) << 16;
                     if (guiRawEvent.Action != RawKeyAction.Down)
@@ -286,7 +294,9 @@ namespace Robust.Client.WebView.Cef
 
                     if (guiRawEvent.Action == RawKeyAction.Up)
                         lParam |= 1 << 31;
-
+#else
+                    var lParam = guiRawEvent.RawCode;
+#endif
                     var modifiers = CalcModifiers(guiRawEvent.Key);
 
                     host.SendKeyEvent(new CefKeyEvent
@@ -307,7 +317,7 @@ namespace Robust.Client.WebView.Cef
                         host.SendKeyEvent(new CefKeyEvent
                         {
                             EventType = CefKeyEventType.Char,
-                            WindowsKeyCode = '\r',
+                            WindowsKeyCode = '\b',
                             NativeKeyCode = lParam,
                             Modifiers = modifiers
                         });

Robust.Client.WebView/Cef/WebViewManagerCef.cs

@@ -1,11 +1,12 @@
 using System;
+using System.Collections.Generic;
 using System.Diagnostics;
 using System.IO;
 using System.Net;
 using System.Reflection;
+using System.Runtime.InteropServices;
 using System.Text;
 using Robust.Client.Console;
-using Robust.Client.Utility;
 using Robust.Shared.Configuration;
 using Robust.Shared.ContentPack;
 using Robust.Shared.IoC;
@@ -44,10 +45,11 @@ namespace Robust.Client.WebView.Cef
                 _localization.GetString("cmd-flushcookies-help"),
                 (_, _, _) => CefCookieManager.GetGlobal(null).FlushStore(null));
 
+#if !MACOS
             string subProcessName;
             if (OperatingSystem.IsWindows())
                 subProcessName = "Robust.Client.WebView.exe";
-            else if (OperatingSystem.IsLinux())
+            else if (OperatingSystem.IsLinux() || OperatingSystem.IsMacOS())
                 subProcessName = "Robust.Client.WebView";
             else
                 throw new NotSupportedException("Unsupported platform for CEF!");
@@ -60,19 +62,39 @@ namespace Robust.Client.WebView.Cef
 
             if (cefResourcesPath == null)
                 throw new InvalidOperationException("Unable to locate cef_resources directory!");
+#endif
 
             var remoteDebugPort = _cfg.GetCVar(WCVars.WebRemoteDebugPort);
 
             var cachePath = FindAndLockCacheDirectory();
 
+#if MACOS
+            NativeLibrary.SetDllImportResolver(typeof(CefSettings).Assembly,
+                (name, assembly, path) =>
+                {
+                    if (name == "libcef")
+                    {
+                        var libPath = PathHelpers.ExecutableRelativeFile("../Frameworks/Chromium Embedded Framework.framework/Chromium Embedded Framework");
+                        return NativeLibrary.Load(libPath, assembly, path);
+                    }
+
+                    return 0;
+                });
+
+            // Needed to implement CefAppProtocol on our NSApplication.
+            NativeLibrary.Load("robust_native_webview", typeof(WebViewManagerCef).Assembly, null);
+#endif
+
             var settings = new CefSettings()
             {
                 WindowlessRenderingEnabled = true, // So we can render to our UI controls.
-                ExternalMessagePump = false, // Unsure, honestly. TODO CEF: Research this?
+                ExternalMessagePump = true,
                 NoSandbox = true, // Not disabling the sandbox crashes CEF.
+#if !MACOS
                 BrowserSubprocessPath = subProcessPath,
                 LocalesDirPath = Path.Combine(cefResourcesPath, "locales"),
                 ResourcesDirPath = cefResourcesPath,
+#endif
                 RemoteDebuggingPort = remoteDebugPort,
                 CookieableSchemesList = "usr,res",
                 CachePath = cachePath,
@@ -113,7 +135,6 @@ namespace Robust.Client.WebView.Cef
             if (ProbeDir(BasePath, out var path))
                 return path;
 
-
             foreach (var searchDir in NativeDllSearchDirectories())
             {
                 if (ProbeDir(searchDir, out path))
@@ -147,6 +168,16 @@ namespace Robust.Client.WebView.Cef
 
         public void Shutdown()
         {
+            foreach (var control in _activeControls.ToArray())
+            {
+                control.CloseBrowser();
+            }
+
+            foreach (var window in _browserWindows.ToArray())
+            {
+                window.Dispose();
+            }
+
             CefRuntime.Shutdown();
         }
 

Robust.Client.WebView/TestBrowseWindow.cs

@@ -8,10 +8,10 @@ internal sealed class TestBrowseWindow : DefaultWindow
 {
     protected override Vector2 ContentsMinimumSize => new Vector2(640, 480);
 
-    public TestBrowseWindow()
+    public TestBrowseWindow(string url)
     {
         var wv = new WebViewControl();
-        wv.Url = "https://spacestation14.io";
+        wv.Url = url;
 
         Contents.AddChild(wv);
     }
@@ -23,6 +23,15 @@ internal sealed class TestBrowseWindowCommand : LocalizedCommands
 
     public override void Execute(IConsoleShell shell, string argStr, string[] args)
     {
-        new TestBrowseWindow().Open();
+        var url = args.Length > 0 ? args[0] : "https://spacestation14.com";
+        new TestBrowseWindow(url).Open();
+    }
+
+    public override CompletionResult GetCompletion(IConsoleShell shell, string[] args)
+    {
+        if (args.Length == 1)
+            return CompletionResult.FromHint("<url>");
+
+        return CompletionResult.Empty;
     }
 }

Robust.Client/Audio/AudioSystem.cs

@@ -3,7 +3,6 @@ using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 using System.Numerics;
 using JetBrains.Annotations;
-using OpenTK.Audio.OpenAL;
 using Robust.Client.GameObjects;
 using Robust.Client.Graphics;
 using Robust.Client.Player;
@@ -17,7 +16,6 @@ using Robust.Shared.Exceptions;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
 using Robust.Shared.Map;
-using Robust.Shared.Map.Components;
 using Robust.Shared.Physics;
 using Robust.Shared.Physics.Components;
 using Robust.Shared.Physics.Systems;
@@ -182,14 +180,16 @@ public sealed partial class AudioSystem : SharedAudioSystem
         }
 
         // If playback position changed then update it.
-        var position = (float) ((entity.Comp.PauseTime ?? Timing.CurTime) - entity.Comp.AudioStart).TotalSeconds;
+        var totalLen = GetAudioLengthImpl(entity.Comp.FileName).TotalSeconds;
+        var position = CalculateAudioPosition(entity, (float) totalLen);
+
         var currentPosition = entity.Comp.Source.PlaybackPosition;
         var diff = Math.Abs(position - currentPosition);
 
         // Don't try to set the audio too far ahead.
         if (!string.IsNullOrEmpty(entity.Comp.FileName))
         {
-            if (position > GetAudioLengthImpl(entity.Comp.FileName).TotalSeconds - _audioEndBuffer)
+            if (position > totalLen - _audioEndBuffer)
             {
                 entity.Comp.StopPlaying();
                 return;
@@ -251,7 +251,7 @@ public sealed partial class AudioSystem : SharedAudioSystem
         length ??= GetAudioLength(component.FileName);
 
         // If audio came into range then start playback at the correct position.
-        var offset = ((entity.Comp.PauseTime ?? Timing.CurTime) - component.AudioStart).TotalSeconds;
+        var offset = CalculateAudioPosition(entity, (float) length.Value.TotalSeconds);
 
         if (TryAudioLimit(component.FileName))
         {
@@ -289,7 +289,7 @@ public sealed partial class AudioSystem : SharedAudioSystem
 
         if (offset > 0)
         {
-            component.PlaybackPosition = (float) offset;
+            component.PlaybackPosition = offset;
         }
     }
 
@@ -755,10 +755,7 @@ public sealed partial class AudioSystem : SharedAudioSystem
         var comp = entity.Comp;
         var source = comp.Source;
 
-        // TODO clamp the offset inside of SetPlaybackPosition() itself.
-        var offset = audioP.PlayOffsetSeconds;
-        var maxOffset = Math.Max((float) stream.Length.TotalSeconds - 0.01f, 0f);
-        offset = Math.Clamp(offset, 0f, maxOffset);
+        var offset = CalculateAudioPosition(entity, (float)stream.Length.TotalSeconds, audioP.PlayOffsetSeconds);
         source.PlaybackPosition = offset;
 
         source.StartPlaying();

Robust.Client/ClientIoC.cs

@@ -13,6 +13,7 @@ using Robust.Client.HWId;
 using Robust.Client.Input;
 using Robust.Client.Localization;
 using Robust.Client.Map;
+using Robust.Client.Network.Transfer;
 using Robust.Client.Placement;
 using Robust.Client.Player;
 using Robust.Client.Profiling;
@@ -41,6 +42,7 @@ using Robust.Shared.IoC;
 using Robust.Shared.Localization;
 using Robust.Shared.Map;
 using Robust.Shared.Network;
+using Robust.Shared.Network.Transfer;
 using Robust.Shared.Physics;
 using Robust.Shared.Player;
 using Robust.Shared.Prototypes;
@@ -174,6 +176,8 @@ namespace Robust.Client
             deps.Register<IXamlProxyHelper, XamlProxyHelper>();
             deps.Register<MarkupTagManager>();
             deps.Register<IHWId, BasicHWId>();
+            deps.Register<ITransferManager, ClientTransferManager>();
+            deps.Register<ClientTransferTestManager>();
         }
     }
 }

Robust.Client/Console/Commands/LauncherAuthCommand.cs

@@ -1,6 +1,9 @@
 #if TOOLS
 using System;
+using System.Collections.Generic;
 using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
 using Microsoft.Data.Sqlite;
 using Robust.Client.Utility;
 using Robust.Shared.Console;
@@ -20,15 +23,7 @@ namespace Robust.Client.Console.Commands
         {
             var wantName = args.Length > 0 ? args[0] : null;
 
-            var basePath = UserDataDir.GetRootUserDataDir(_gameController);
-            var launcherDirName = Environment.GetEnvironmentVariable("SS14_LAUNCHER_APPDATA_NAME") ?? "launcher";
-            var dbPath = Path.Combine(basePath, launcherDirName, "settings.db");
-
-#if USE_SYSTEM_SQLITE
-            SQLitePCL.raw.SetProvider(new SQLitePCL.SQLite3Provider_sqlite3());
-#endif
-            using var con = new SqliteConnection($"Data Source={dbPath};Mode=ReadOnly");
-            con.Open();
+            using var con = GetDb();
             using var cmd = con.CreateCommand();
             cmd.CommandText = "SELECT UserId, UserName, Token FROM Login WHERE Expires > datetime('NOW')";
 
@@ -57,6 +52,51 @@ namespace Robust.Client.Console.Commands
 
             shell.WriteLine($"Logged into account {userName}");
         }
+
+        public override async ValueTask<CompletionResult> GetCompletionAsync(
+            IConsoleShell shell,
+            string[] args,
+            string argStr,
+            CancellationToken cancel)
+        {
+            if (args.Length != 1)
+                return CompletionResult.Empty;
+
+            return await Task.Run(() =>
+                {
+                    using var con = GetDb();
+
+                    using var cmd = con.CreateCommand();
+                    cmd.CommandText = "SELECT UserName FROM Login WHERE Expires > datetime('NOW')";
+
+                    var options = new List<CompletionOption>();
+
+                    using var reader = cmd.ExecuteReader();
+                    while (reader.Read())
+                    {
+                        var name = reader.GetString(0);
+                        options.Add(new CompletionOption(name));
+                    }
+
+                    return CompletionResult.FromOptions(options);
+                },
+                cancel);
+        }
+
+        private SqliteConnection GetDb()
+        {
+            var basePath = UserDataDir.GetRootUserDataDir(_gameController);
+            var launcherDirName = Environment.GetEnvironmentVariable("SS14_LAUNCHER_APPDATA_NAME") ?? "launcher";
+            var dbPath = Path.Combine(basePath, launcherDirName, "settings.db");
+
+#if USE_SYSTEM_SQLITE
+            SQLitePCL.raw.SetProvider(new SQLitePCL.SQLite3Provider_sqlite3());
+#endif
+            var con = new SqliteConnection($"Data Source={dbPath};Mode=ReadOnly");
+            con.Open();
+
+            return con;
+        }
     }
 }
 

Robust.Client/GameController/GameController.cs

@@ -11,6 +11,7 @@ using Robust.Client.GameObjects;
 using Robust.Client.GameStates;
 using Robust.Client.Graphics;
 using Robust.Client.Input;
+using Robust.Client.Network.Transfer;
 using Robust.Client.Placement;
 using Robust.Client.Replays.Loading;
 using Robust.Client.Replays.Playback;
@@ -35,6 +36,7 @@ using Robust.Shared.Localization;
 using Robust.Shared.Log;
 using Robust.Shared.Map;
 using Robust.Shared.Network;
+using Robust.Shared.Network.Transfer;
 using Robust.Shared.Profiling;
 using Robust.Shared.Prototypes;
 using Robust.Shared.Reflection;
@@ -98,6 +100,8 @@ namespace Robust.Client
         [Dependency] private readonly ILocalizationManager _loc = default!;
         [Dependency] private readonly ISystemFontManagerInternal _systemFontManager = default!;
         [Dependency] private readonly LoadingScreenManager _loadscr = default!;
+        [Dependency] private readonly ITransferManager _transfer = default!;
+        [Dependency] private readonly ClientTransferTestManager _transferTest = default!;
 
         private IWebViewManagerHook? _webViewHook;
 
@@ -107,6 +111,7 @@ namespace Robust.Client
         private IMainArgs? _loaderArgs;
 
         public bool ContentStart { get; set; } = false;
+        public StartType StartTypeValue { get; private set; }
         public GameControllerOptions Options { get; private set; } = new();
         public InitialLaunchState LaunchState { get; private set; } = default!;
 
@@ -200,7 +205,14 @@ namespace Robust.Client
                 _logManager.GetSawmill("res"));
 
             _loadscr.LoadingStep(_resourceCache.PreloadTextures, "Texture preload");
-            _loadscr.LoadingStep(() => { _networkManager.Initialize(false); }, _networkManager);
+            _loadscr.LoadingStep(() =>
+                {
+                    _networkManager.Initialize(false);
+                    _transfer.Initialize();
+                    _transferTest.Initialize();
+                },
+                _networkManager);
+
             _loadscr.LoadingStep(_configurationManager.SetupNetworking, _configurationManager);
             _loadscr.LoadingStep(_serializer.Initialize, _serializer);
             _loadscr.LoadingStep(_inputManager.Initialize, _inputManager);
@@ -424,9 +436,18 @@ namespace Robust.Client
                 ? MountOptions.Merge(_commandLineArgs.MountOptions, Options.MountOptions)
                 : Options.MountOptions;
 
+            StartTypeValue = ContentStart ? StartType.Content : StartType.Engine;
+#if FULL_RELEASE
+            if (_loaderArgs != null || Options.ResourceMountDisabled)
+                StartTypeValue = StartType.Loader;
+#else
+            if (StartTypeValue == StartType.Content && Path.GetFileName(PathHelpers.GetExecutableDirectory()) == "MacOS")
+                StartTypeValue = StartType.ContentAppBundle;
+#endif
+
             ProgramShared.DoMounts(_resManager, mountOptions, Options.ContentBuildDirectory,
                 Options.AssemblyDirectory,
-                Options.LoadContentResources, _loaderArgs != null && !Options.ResourceMountDisabled, ContentStart);
+                Options.LoadContentResources, StartTypeValue);
 
             if (_loaderArgs != null)
             {
@@ -675,6 +696,11 @@ namespace Robust.Client
                 _modLoader.BroadcastUpdate(ModUpdateLevel.FramePostEngine, frameEventArgs);
             }
 
+            using (_prof.Group("Transfer"))
+            {
+                _transfer.FrameUpdate();
+            }
+
             _audio.FlushALDisposeQueues();
         }
 

Robust.Client/GameObjects/Components/Renderable/SpriteComponent.cs

@@ -1336,11 +1336,10 @@ namespace Robust.Client.GameObjects
             public Layer(Layer toClone, SpriteComponent parent) : this(parent)
             {
                 if (toClone.Shader != null)
-                {
                     Shader = toClone.Shader.Mutable ? toClone.Shader.Duplicate() : toClone.Shader;
-                    UnShaded = toClone.UnShaded;
-                    ShaderPrototype = toClone.ShaderPrototype;
-                }
+
+                UnShaded = toClone.UnShaded;
+                ShaderPrototype = toClone.ShaderPrototype;
                 Texture = toClone.Texture;
                 RSI = toClone.RSI;
                 State = toClone.State;

Robust.Client/GameObjects/EntitySystems/AnimationPlayerSystem.cs

@@ -14,9 +14,9 @@ namespace Robust.Client.GameObjects
         private EntityQuery<AnimationPlayerComponent> _playerQuery;
         private EntityQuery<MetaDataComponent> _metaQuery;
 
-#pragma warning disable CS0414
+#if DEBUG
         [Dependency] private readonly IComponentFactory _compFact = default!;
-#pragma warning restore CS0414
+#endif
 
         public override void Initialize()
         {
@@ -154,6 +154,9 @@ namespace Robust.Client.GameObjects
             }
 
             ent.Comp.PlayingAnimations.Add(key, playback);
+
+            var startedEvent = new AnimationStartedEvent(ent.Owner, ent.Comp, key);
+            RaiseLocalEvent(ent.Owner, startedEvent, true);
         }
 
         public bool HasRunningAnimation(EntityUid uid, string key)
@@ -199,6 +202,34 @@ namespace Robust.Client.GameObjects
         }
     }
 
+    /// <summary>
+    /// Raised whenever an animation started playing.
+    /// </summary>
+    public sealed class AnimationStartedEvent : EntityEventArgs
+    {
+        /// <summary>
+        /// The entity associated with the event.
+        /// </summary>
+        public EntityUid Uid { get; init; }
+
+        /// <summary>
+        /// The animation player component associated with the entity this event was raised on.
+        /// </summary>
+        public AnimationPlayerComponent AnimationPlayer { get; init; }
+
+        /// <summary>
+        /// The key associated with the animation that was started.
+        /// </summary>
+        public string Key { get; init; } = string.Empty;
+
+        internal AnimationStartedEvent(EntityUid uid, AnimationPlayerComponent animationPlayer, string key)
+        {
+            Uid = uid;
+            AnimationPlayer = animationPlayer;
+            Key = key;
+        }
+    }
+
     /// <summary>
     /// Raised whenever an animation stops, either due to running its course or being stopped manually.
     /// </summary>

Robust.Client/Graphics/Clyde/Clyde.HLR.cs

@@ -493,6 +493,9 @@ namespace Robust.Client.Graphics.Clyde
         {
             if (viewport.Eye == null || viewport.Eye.Position.MapId == MapId.Nullspace)
             {
+                if (viewport.ClearWhenMissingEye)
+                    RenderInRenderTarget(viewport.RenderTarget, () => { }, viewport.ClearColor);
+
                 return;
             }
 

Robust.Client/Graphics/Clyde/Clyde.Viewport.cs

@@ -138,6 +138,7 @@ namespace Robust.Client.Graphics.Clyde
             public Vector2i Size { get; set; }
             public event Action<ClearCachedViewportResourcesEvent>? ClearCachedResources;
             public Color? ClearColor { get; set; } = Color.Black;
+            public bool ClearWhenMissingEye { get; set; }
             public Vector2 RenderScale { get; set; } = Vector2.One;
             public bool AutomaticRender { get; set; }
             public long Id { get; }

Robust.Client/Graphics/Clyde/Clyde.Windowing.cs

@@ -601,6 +601,11 @@ namespace Robust.Client.Graphics.Clyde
                 _clyde._windowing!.TextInputStop(Reg);
             }
 
+            public void SetWindowProgress(WindowProgressState state, float value)
+            {
+                _clyde._windowing!.WindowSetProgress(Reg, state, value);
+            }
+
             public nint? WindowsHWnd => _clyde._windowing!.WindowGetWin32Window(Reg);
         }
 

Robust.Client/Graphics/Clyde/Clyde.cs

@@ -91,6 +91,8 @@ namespace Robust.Client.Graphics.Clyde
         private bool _earlyGLInit;
         private bool _threadWindowApi;
 
+        public bool IsInitialized { get; private set; }
+
         public Clyde()
         {
             _currentBoundRenderTarget = default!;
@@ -183,6 +185,8 @@ namespace Robust.Client.Graphics.Clyde
             if (!InitMainWindowAndRenderer())
                 return false;
 
+            IsInitialized = true;
+
             return true;
         }
 

Robust.Client/Graphics/Clyde/ClydeHeadless.cs

@@ -27,6 +27,7 @@ namespace Robust.Client.Graphics.Clyde
     internal sealed class ClydeHeadless : IClydeInternal
     {
         // Would it make sense to report a fake resolution like 720p here so code doesn't break? idk.
+        public bool IsInitialized { get; private set; }
         public IClydeWindow MainWindow { get; }
         public Vector2i ScreenSize => (1280, 720);
         public IEnumerable<IClydeWindow> AllWindows => _windows;
@@ -172,6 +173,7 @@ namespace Robust.Client.Graphics.Clyde
 
         public bool InitializePostWindowing()
         {
+            IsInitialized = true;
             return true;
         }
 
@@ -524,6 +526,7 @@ namespace Robust.Client.Graphics.Clyde
             public Vector2i Size { get; }
             public event Action<ClearCachedViewportResourcesEvent>? ClearCachedResources;
             public Color? ClearColor { get; set; } = Color.Black;
+            public bool ClearWhenMissingEye { get; set; }
             public Vector2 RenderScale { get; set; }
             public bool AutomaticRender { get; set; }
 
@@ -582,6 +585,11 @@ namespace Robust.Client.Graphics.Clyde
             public event Action<WindowDestroyedEventArgs>? Destroyed;
             public event Action<WindowResizedEventArgs>? Resized { add { } remove { } }
 
+            public void SetWindowProgress(WindowProgressState state, float value)
+            {
+                // Nop.
+            }
+
             public void TextInputSetRect(UIBox2i rect, int cursor)
             {
                 // Nop.

Robust.Client/Graphics/Clyde/Windowing/IWindowingImpl.cs

@@ -42,6 +42,7 @@ namespace Robust.Client.Graphics.Clyde
             void WindowSetSize(WindowReg window, Vector2i size);
             void WindowSetVisible(WindowReg window, bool visible);
             void WindowRequestAttention(WindowReg window);
+            void WindowSetProgress(WindowReg reg, WindowProgressState state, float value);
             void WindowSwapBuffers(WindowReg window);
             uint? WindowGetX11Id(WindowReg window);
             nint? WindowGetX11Display(WindowReg window);

Robust.Client/Graphics/Clyde/Windowing/Sdl3.Cursor.cs

@@ -38,7 +38,7 @@ internal partial class Clyde
 
             fixed (Rgba32* pixPtr = img.GetPixelSpan())
             {
-                var surface = SDL.SDL_CreateSurfaceFrom(
+                var surface = (nint) SDL.SDL_CreateSurfaceFrom(
                     img.Width,
                     img.Height,
                     SDL.SDL_PixelFormat.SDL_PIXELFORMAT_ABGR8888,

Robust.Client/Graphics/Clyde/Windowing/Sdl3.Event.cs

@@ -163,7 +163,7 @@ internal partial class Clyde
 
             var button = ConvertSdl3Button(ev.Button);
             var key = Mouse.MouseButtonToKey(button);
-            EmitKeyEvent(key, ev.Type, false, ev.Mods, 0);
+            EmitKeyEvent(key, ev.Type, false, ev.Mods, 0, 0);
         }
 
         private void ProcessEventMouseMotion(EventMouseMotion ev)
@@ -227,10 +227,10 @@ internal partial class Clyde
 
         private void ProcessEventKey(EventKey ev)
         {
-            EmitKeyEvent(ConvertSdl3Scancode(ev.Scancode), ev.Type, ev.Repeat, ev.Mods, ev.Scancode);
+            EmitKeyEvent(ConvertSdl3Scancode(ev.Scancode), ev.Type, ev.Repeat, ev.Mods, ev.Scancode, ev.Raw);
         }
 
-        private void EmitKeyEvent(Key key, ET type, bool repeat, SDL.SDL_Keymod mods, SDL.SDL_Scancode scancode)
+        private void EmitKeyEvent(Key key, ET type, bool repeat, SDL.SDL_Keymod mods, SDL.SDL_Scancode scancode, ushort rawCode)
         {
             var shift = (mods & SDL_Keymod.SDL_KMOD_SHIFT) != 0;
             var alt = (mods & SDL_Keymod.SDL_KMOD_ALT) != 0;
@@ -241,7 +241,8 @@ internal partial class Clyde
                 key,
                 repeat,
                 alt, control, shift, system,
-                (int)scancode);
+                (int)scancode,
+                rawCode);
 
             switch (type)
             {

Robust.Client/Graphics/Clyde/Windowing/Sdl3.RawEvent.cs

@@ -140,6 +140,7 @@ internal partial class Clyde
             {
                 WindowId = ev.windowID,
                 Scancode = ev.scancode,
+                Raw = ev.raw,
                 Type = ev.type,
                 Repeat = ev.repeat,
                 Mods = ev.mod,
@@ -194,6 +195,7 @@ internal partial class Clyde
         {
             public uint WindowId;
             public SDL.SDL_Scancode Scancode;
+            public ushort Raw;
             public ET Type;
             public bool Repeat;
             public SDL.SDL_Keymod Mods;

Robust.Client/Graphics/Clyde/Windowing/Sdl3.Window.cs

@@ -21,6 +21,7 @@ internal partial class Clyde
     private sealed partial class Sdl3WindowingImpl
     {
         private int _nextWindowId = 1;
+        private bool _progressUnavailable;
 
         public (WindowReg?, string? error) WindowCreate(
             GLContextSpec? spec,
@@ -438,7 +439,8 @@ internal partial class Clyde
 
         private static void WinThreadWinSetSize(CmdWinSetSize cmd)
         {
-            SDL.SDL_SetWindowSize(cmd.Window, cmd.W, cmd.H);
+            var density = SDL.SDL_GetWindowPixelDensity(cmd.Window);
+            SDL.SDL_SetWindowSize(cmd.Window, (int)(cmd.W / density), (int)(cmd.H / density));
         }
 
         private static void WinThreadWinSetVisible(CmdWinSetVisible cmd)
@@ -461,6 +463,42 @@ internal partial class Clyde
                 _sawmill.Error("Failed to flash window: {error}", SDL.SDL_GetError());
         }
 
+        public void WindowSetProgress(WindowReg window, WindowProgressState state, float value)
+        {
+            SendCmd(new CmdWinSetProgress
+            {
+                Window = WinPtr(window),
+                State = (SDL.SDL_ProgressState)state,
+                Value = value
+            });
+        }
+
+        private void WinThreadWinSetProgress(CmdWinSetProgress cmd)
+        {
+            if (_progressUnavailable)
+                return;
+
+            try
+            {
+                var res = SDL.SDL_SetWindowProgressState(cmd.Window, cmd.State);
+                if (!res)
+                {
+                    _sawmill.Error("Failed to set window progress state: {error}", SDL.SDL_GetError());
+                    return;
+                }
+
+                res = SDL.SDL_SetWindowProgressValue(cmd.Window, cmd.Value);
+                if (!res)
+                    _sawmill.Error("Failed to set window progress value: {error}", SDL.SDL_GetError());
+            }
+            catch (EntryPointNotFoundException)
+            {
+                // Allowing it to fail means I don't have to update the launcher immediately :)
+                _progressUnavailable = true;
+                _sawmill.Debug("SDL3 progress APIs unavailable");
+            }
+        }
+
         public unsafe void WindowSwapBuffers(WindowReg window)
         {
             var reg = (Sdl3WindowReg)window;

Robust.Client/Graphics/Clyde/Windowing/Sdl3.WindowIcons.cs

@@ -75,7 +75,7 @@ internal partial class Clyde
                 IntPtr surface;
                 fixed (byte* ptr = copied)
                 {
-                    surface = SDL.SDL_CreateSurfaceFrom(
+                    surface = (nint) SDL.SDL_CreateSurfaceFrom(
                         img.Width,
                         img.Height,
                         SDL.SDL_PixelFormat.SDL_PIXELFORMAT_ABGR8888,

Robust.Client/Graphics/Clyde/Windowing/Sdl3.WindowThread.cs

@@ -93,6 +93,10 @@ internal partial class Clyde
                     WinThreadWinRequestAttention(cmd);
                     break;
 
+                case CmdWinSetProgress cmd:
+                    WinThreadWinSetProgress(cmd);
+                    break;
+
                 case CmdWinSetSize cmd:
                     WinThreadWinSetSize(cmd);
                     break;
@@ -261,6 +265,13 @@ internal partial class Clyde
             public nint Window;
         }
 
+        private sealed class CmdWinSetProgress : CmdBase
+        {
+            public nint Window;
+            public SDL.SDL_ProgressState State;
+            public float Value;
+        }
+
         private sealed class CmdWinSetSize : CmdBase
         {
             public nint Window;

Robust.Client/Graphics/IClyde.cs

@@ -18,6 +18,8 @@ namespace Robust.Client.Graphics
     [NotContentImplementable]
     public interface IClyde
     {
+        internal bool IsInitialized { get; }
+
         IClydeWindow MainWindow { get; }
         IRenderTarget MainWindowRenderTarget => MainWindow.RenderTarget;
 

Robust.Client/Graphics/IClydeViewport.cs

@@ -43,6 +43,11 @@ namespace Robust.Client.Graphics
         /// </summary>
         Color? ClearColor { get; set; }
 
+        /// <summary>
+        /// On frames where Eye is null or in nullspace, whether the viewport may clear.
+        /// </summary>
+        bool ClearWhenMissingEye { get; set; }
+
         /// <summary>
         ///     This is, effectively, a multiplier to the eye's zoom.
         /// </summary>

Robust.Client/Graphics/IClydeWindow.cs

@@ -2,6 +2,7 @@
 using System.Numerics;
 using Robust.Shared.Map;
 using Robust.Shared.Maths;
+using SDL3;
 
 namespace Robust.Client.Graphics
 {
@@ -43,6 +44,8 @@ namespace Robust.Client.Graphics
         /// </summary>
         event Action<WindowResizedEventArgs> Resized;
 
+        internal void SetWindowProgress(WindowProgressState state, float value);
+
         /// <summary>
         /// Set the active text input area in window pixel coordinates.
         /// </summary>
@@ -68,6 +71,15 @@ namespace Robust.Client.Graphics
         void TextInputStop();
     }
 
+    internal enum WindowProgressState : byte
+    {
+        None = SDL.SDL_ProgressState.SDL_PROGRESS_STATE_NONE,
+        Indeterminate = SDL.SDL_ProgressState.SDL_PROGRESS_STATE_INDETERMINATE,
+        Normal = SDL.SDL_ProgressState.SDL_PROGRESS_STATE_NORMAL,
+        Paused = SDL.SDL_ProgressState.SDL_PROGRESS_STATE_PAUSED,
+        Error = SDL.SDL_ProgressState.SDL_PROGRESS_STATE_ERROR
+    }
+
     [NotContentImplementable]
     internal interface IClydeWindowInternal : IClydeWindow
     {

Robust.Client/Graphics/LoadingScreenManager.cs

@@ -118,6 +118,13 @@ internal sealed class LoadingScreenManager : ILoadingScreenManager
 
         _currentSectionName = sectionName;
 
+        if (_clyde.IsInitialized)
+        {
+            _clyde.MainWindow.SetWindowProgress(
+                WindowProgressState.Normal,
+                _currentSection / (float)_numberOfLoadingSections);
+        }
+
         if (!dontRender)
         {
             // This ensures that if the screen was resized or something the new size is properly updated to clyde.
@@ -176,6 +183,8 @@ internal sealed class LoadingScreenManager : ILoadingScreenManager
         if (_currentSection != _numberOfLoadingSections)
             _sawmill.Error($"The number of seen loading sections isn't equal to the total number of loading sections! Seen: {_currentSection}, Total: {_numberOfLoadingSections}");
 
+        _clyde.MainWindow.SetWindowProgress(WindowProgressState.None, 1);
+
         _finished = true;
     }
 

Robust.Client/IGameControllerInternal.cs

@@ -1,5 +1,6 @@
 using System;
 using Robust.Client.Input;
+using Robust.Shared;
 using Robust.Shared.Log;
 using Robust.Shared.Timing;
 
@@ -9,6 +10,7 @@ namespace Robust.Client
     {
         GameControllerOptions Options { get; }
         bool ContentStart { get; set; }
+        StartType StartTypeValue { get; }
         void SetCommandLineArgs(CommandLineArgs args);
         void Run(GameController.DisplayMode mode, GameControllerOptions options, Func<ILogHandler>? logHandlerFactory = null);
         void KeyDown(KeyEventArgs keyEvent);

Robust.Client/Input/Events.cs

@@ -106,17 +106,20 @@ namespace Robust.Client.Input
         public bool IsRepeat { get; }
 
         public int ScanCode { get; }
+        internal ushort RawCode { get; }
 
         public KeyEventArgs(
             Keyboard.Key key,
             bool repeat,
             bool alt, bool control, bool shift, bool system,
-            int scanCode)
+            int scanCode,
+            ushort rawCode=0)
             : base(alt, control, shift, system)
         {
             Key = key;
             IsRepeat = repeat;
             ScanCode = scanCode;
+            RawCode = rawCode;
         }
     }
 

Robust.Client/Input/InputManager.cs

@@ -306,7 +306,8 @@ namespace Robust.Client.Input
                 args.Key,
                 args.ScanCode,
                 action,
-                (Vector2i) (mousePos ?? Vector2.Zero));
+                (Vector2i) (mousePos ?? Vector2.Zero),
+                args.RawCode);
 
             var block = rawInput.RawKeyEvent(keyEvent);
             return block;

Robust.Client/Network/Transfer/ClientTransferImplWebSocket.cs

@@ -0,0 +1,48 @@
+using System;
+using System.Net.WebSockets;
+using System.Threading;
+using System.Threading.Tasks;
+using Robust.Shared.Log;
+using Robust.Shared.Network;
+using Robust.Shared.Network.Transfer;
+
+namespace Robust.Client.Network.Transfer;
+
+internal sealed class ClientTransferImplWebSocket : TransferImplWebSocket
+{
+    private readonly (string EndpointUrl, byte[] Key) _info;
+    private readonly bool _slow;
+
+    public ClientTransferImplWebSocket(
+        (string EndpointUrl, byte[] Key) info,
+        ISawmill sawmill,
+        BaseTransferManager parent,
+        INetChannel channel,
+        bool slow)
+        : base(sawmill, parent, channel)
+    {
+        _info = info;
+        _slow = slow;
+    }
+
+    public override async Task ClientInit(CancellationToken cancel)
+    {
+        var clientWs = new ClientWebSocket();
+        clientWs.Options.SetRequestHeader(KeyHeaderName, Convert.ToBase64String(_info.Key));
+        clientWs.Options.SetRequestHeader(UserIdHeaderName, Channel.UserId.ToString());
+
+        if (_slow)
+            await Task.Delay(2000, cancel);
+
+        await clientWs.ConnectAsync(new Uri(_info.EndpointUrl), cancel);
+
+        WebSocket = clientWs;
+
+        ReadThread();
+    }
+
+    public override Task ServerInit()
+    {
+        throw new NotSupportedException();
+    }
+}

Robust.Client/Network/Transfer/ClientTransferManager.cs

@@ -0,0 +1,89 @@
+using System;
+using System.IO;
+using System.Threading.Tasks;
+using Robust.Shared;
+using Robust.Shared.Asynchronous;
+using Robust.Shared.Configuration;
+using Robust.Shared.Log;
+using Robust.Shared.Network;
+using Robust.Shared.Network.Messages.Transfer;
+using Robust.Shared.Network.Transfer;
+
+namespace Robust.Client.Network.Transfer;
+
+internal sealed class ClientTransferManager : BaseTransferManager, ITransferManager
+{
+    private readonly IClientNetManager _netManager;
+    private readonly IConfigurationManager _cfg;
+    private BaseTransferImpl? _transferImpl;
+
+    public event Action? ClientHandshakeComplete;
+
+    internal ClientTransferManager(
+        IClientNetManager netManager,
+        ILogManager logManager,
+        ITaskManager taskManager,
+        IConfigurationManager cfg)
+        : base(logManager, NetMessageAccept.Client, taskManager)
+    {
+        _netManager = netManager;
+        _cfg = cfg;
+    }
+
+    public Stream StartTransfer(INetChannel channel, TransferStartInfo startInfo)
+    {
+        if (_transferImpl == null)
+            throw new InvalidOperationException("Not connected yet!");
+
+        if (channel != _netManager.ServerChannel)
+            throw new InvalidOperationException("Invalid channel!");
+
+        return _transferImpl.StartTransfer(startInfo);
+    }
+
+    public void Initialize()
+    {
+        _netManager.RegisterNetMessage<MsgTransferInit>(RxTransferInit, NetMessageAccept.Client | NetMessageAccept.Handshake);
+        _netManager.RegisterNetMessage<MsgTransferAckInit>();
+        _netManager.RegisterNetMessage<MsgTransferData>(RxTransferData, NetMessageAccept.Client | NetMessageAccept.Handshake);
+    }
+
+    private async void RxTransferInit(MsgTransferInit message)
+    {
+        BaseTransferImpl impl;
+        if (message.HttpInfo is { } httpInfo)
+        {
+            impl = new ClientTransferImplWebSocket(
+                httpInfo,
+                Sawmill,
+                this,
+                message.MsgChannel,
+                _cfg.GetCVar(CVars.TransferArtificialDelay));
+        }
+        else
+        {
+            impl = new TransferImplLidgren(Sawmill, message.MsgChannel, this, _netManager);
+        }
+
+        _transferImpl = impl;
+        await _transferImpl.ClientInit(default);
+
+        ClientHandshakeComplete?.Invoke();
+    }
+
+    private void RxTransferData(MsgTransferData message)
+    {
+        if (_transferImpl is not TransferImplLidgren lidgren)
+        {
+            message.MsgChannel.Disconnect("Not lidgren");
+            return;
+        }
+
+        lidgren.ReceiveData(message);
+    }
+
+    public Task ServerHandshake(INetChannel channel)
+    {
+        throw new NotSupportedException();
+    }
+}

Robust.Client/Network/Transfer/ClientTransferTestManager.cs

@@ -0,0 +1,14 @@
+using Robust.Shared.Log;
+using Robust.Shared.Network;
+using Robust.Shared.Network.Transfer;
+
+namespace Robust.Client.Network.Transfer;
+
+internal sealed class ClientTransferTestManager(ITransferManager manager, ILogManager logManager)
+    : TransferTestManager(manager, logManager)
+{
+    protected override bool PermissionCheck(INetChannel channel)
+    {
+        return true;
+    }
+}

Robust.Client/Prototypes/ClientPrototypeManager.cs

@@ -13,9 +13,9 @@ namespace Robust.Client.Prototypes
     public sealed class ClientPrototypeManager : PrototypeManager
     {
         [Dependency] private readonly INetManager _netManager = default!;
-#pragma warning disable CS0414
+#if TOOLS
         [Dependency] private readonly IClientGameTiming _timing = default!;
-#pragma warning restore CS0414
+#endif
         [Dependency] private readonly IGameControllerInternal _controller = default!;
         [Dependency] private readonly IReloadManager _reload = default!;
 

Robust.Client/Replays/Loading/ReplayLoadManager.Checkpoints.cs

@@ -279,10 +279,7 @@ public sealed partial class ReplayLoadManager
                     var path = resUpload.RelativePath.Clean().ToRelativePath();
                     if (uploadedFiles.Add(path) && !_netResMan.FileExists(path))
                     {
-                        _netMan.DispatchLocalNetMessage(new NetworkResourceUploadMessage
-                        {
-                            RelativePath = path, Data = resUpload.Data
-                        });
+                        _netResMan.StoreFile(path, resUpload.Data);
                         message.Messages.RemoveSwap(i);
                         break;
                     }

Robust.Client/Replays/Loading/ReplayLoadManager.cs

@@ -21,7 +21,6 @@ public sealed partial class ReplayLoadManager : IReplayLoadManager
     [Dependency] private readonly IBaseClient _client = default!;
     [Dependency] private readonly EntityManager _entMan = default!;
     [Dependency] private readonly IClientGameTiming _timing = default!;
-    [Dependency] private readonly IClientNetManager _netMan = default!;
     [Dependency] private readonly IComponentFactory _factory = default!;
     [Dependency] private readonly IPrototypeManager _protoMan = default!;
     [Dependency] private readonly ILocalizationManager _locMan = default!;

Robust.Client/Upload/Commands/UploadFileCommand.cs

@@ -4,7 +4,6 @@ using Robust.Shared;
 using Robust.Shared.Configuration;
 using Robust.Shared.Console;
 using Robust.Shared.IoC;
-using Robust.Shared.Network;
 using Robust.Shared.Upload;
 using Robust.Shared.Utility;
 
@@ -14,7 +13,7 @@ public sealed class UploadFileCommand : IConsoleCommand
 {
     [Dependency] private readonly IConfigurationManager _cfgManager = default!;
     [Dependency] private readonly IFileDialogManager _dialog = default!;
-    [Dependency] private readonly INetManager _netManager = default!;
+    [Dependency] private readonly NetworkResourceManager _netRes = default!;
 
     public string Command => "uploadfile";
     public string Description => "Uploads a resource to the server.";
@@ -55,12 +54,6 @@ public sealed class UploadFileCommand : IConsoleCommand
 
         var data = file.CopyToArray();
 
-        var msg = new NetworkResourceUploadMessage
-        {
-            RelativePath = path,
-            Data = data
-        };
-
-        _netManager.ClientSendMessage(msg);
+        _netRes.UploadResources([(path, data)]);
     }
 }

Robust.Client/Upload/Commands/UploadFolderCommand.cs

@@ -1,4 +1,4 @@
-using System;
+using System.Collections.Generic;
 using System.IO;
 using Robust.Shared;
 using Robust.Shared.Configuration;
@@ -6,7 +6,6 @@ using Robust.Shared.Console;
 using Robust.Shared.ContentPack;
 using Robust.Shared.IoC;
 using Robust.Shared.Localization;
-using Robust.Shared.Network;
 using Robust.Shared.Upload;
 using Robust.Shared.Utility;
 
@@ -14,9 +13,9 @@ namespace Robust.Client.Upload.Commands;
 
 public sealed class UploadFolderCommand : IConsoleCommand
 {
-    [Dependency] private IResourceManager _resourceManager = default!;
-    [Dependency] private IConfigurationManager _configManager = default!;
-    [Dependency] private INetManager _netMan = default!;
+    [Dependency] private readonly IResourceManager _resourceManager = default!;
+    [Dependency] private readonly IConfigurationManager _configManager = default!;
+    [Dependency] private readonly NetworkResourceManager _netRes = default!;
 
     public string Command => "uploadfolder";
     public string Description => Loc.GetString("uploadfolder-command-description");
@@ -50,6 +49,7 @@ public sealed class UploadFolderCommand : IConsoleCommand
         }
 
         //Grab all files in specified folder and upload them
+        var files = new List<(ResPath Relative, byte[] Data)>();
         foreach (var filepath in _resourceManager.UserData.Find($"{folderPath.ToRelativePath()}/").files )
         {
             await using var filestream = _resourceManager.UserData.Open(filepath, FileMode.Open);
@@ -63,17 +63,14 @@ public sealed class UploadFolderCommand : IConsoleCommand
 
                 var data = filestream.CopyToArray();
 
-                var msg = new NetworkResourceUploadMessage
-                {
-                    RelativePath = filepath.RelativeTo(BaseUploadFolderPath),
-                    Data = data
-                };
+                files.Add((filepath.RelativeTo(BaseUploadFolderPath), data));
 
-                _netMan.ClientSendMessage(msg);
                 fileCount++;
             }
         }
 
+        _netRes.UploadResources(files);
+
         shell.WriteLine( Loc.GetString("uploadfolder-command-success",("fileCount",fileCount)));
     }
 }

Robust.Client/Upload/NetworkResourceManager.cs

@@ -1,5 +1,11 @@
+using System;
+using System.Buffers.Binary;
+using System.Collections.Generic;
 using Robust.Shared.IoC;
+using Robust.Shared.Network;
+using Robust.Shared.Network.Transfer;
 using Robust.Shared.Upload;
+using Robust.Shared.Utility;
 
 namespace Robust.Client.Upload;
 
@@ -7,10 +13,44 @@ public sealed class NetworkResourceManager : SharedNetworkResourceManager
 {
     [Dependency] private readonly IBaseClient _client = default!;
 
-    public override void Initialize()
+    internal override void Initialize()
     {
         base.Initialize();
+
         _client.RunLevelChanged += OnLevelChanged;
+
+        TransferManager.RegisterTransferMessage(TransferKeyNetworkUpload);
+        TransferManager.RegisterTransferMessage(TransferKeyNetworkDownload, ReceiveDownload);
+
+        NetManager.RegisterNetMessage<NetworkResourceAckMessage>();
+    }
+
+    private async void ReceiveDownload(TransferReceivedEvent transfer)
+    {
+        Sawmill.Debug("Receiving file download transfer!");
+
+        await using var stream = transfer.DataStream;
+
+        try
+        {
+            var ackKeyBytes = new byte[4];
+            await stream.ReadExactlyAsync(ackKeyBytes);
+            var ackKey = BinaryPrimitives.ReadInt32LittleEndian(ackKeyBytes);
+
+            await IngestFileStream(stream);
+
+            if (ackKey != 0)
+            {
+                NetManager.ClientSendMessage(new NetworkResourceAckMessage
+                {
+                    Key = ackKey
+                });
+            }
+        }
+        catch (Exception e)
+        {
+            Sawmill.Error($"Error while downloading transfer resources: {e}");
+        }
     }
 
     private void OnLevelChanged(object? sender, RunLevelChangedEventArgs e)
@@ -27,4 +67,20 @@ public sealed class NetworkResourceManager : SharedNetworkResourceManager
     {
         ContentRoot.Clear();
     }
+
+    internal async void UploadResources(List<(ResPath Relative, byte[] Data)> files)
+    {
+        var clientNet = (IClientNetManager)NetManager;
+        if (clientNet.ServerChannel is not { } channel)
+            throw new InvalidOperationException("Not connected to server!");
+
+        await using var transfer = TransferManager.StartTransfer(
+            channel,
+            new TransferStartInfo
+            {
+                MessageKey = TransferKeyNetworkUpload,
+            });
+
+        await WriteFileStream(transfer, files);
+    }
 }

Robust.Client/UserInterface/Control.Animations.cs

@@ -12,6 +12,7 @@ namespace Robust.Client.UserInterface
     {
         private Dictionary<string, AnimationPlayback>? _playingAnimations;
 
+        public Action<string>? AnimationStarted;
         public Action<string>? AnimationCompleted;
 
         /// <summary>
@@ -27,6 +28,7 @@ namespace Robust.Client.UserInterface
 
             _playingAnimations ??= new Dictionary<string, AnimationPlayback>();
             _playingAnimations.Add(key, playback);
+            AnimationStarted?.Invoke(key);
         }
 
         public bool HasRunningAnimation(string key)

Robust.Client/UserInterface/Control.Layout.cs

@@ -2,6 +2,7 @@ using System;
 using System.Numerics;
 using Robust.Client.Graphics;
 using Robust.Client.UserInterface.Controls;
+using Robust.Shared.Animations;
 using Robust.Shared.Map;
 using Robust.Shared.Maths;
 using Robust.Shared.ViewVariables;
@@ -355,6 +356,7 @@ namespace Robust.Client.UserInterface
         /// </remarks>
         /// <seealso cref="MinWidth"/>
         /// <seealso cref="MinHeight"/>
+        [Animatable]
         public Vector2 MinSize
         {
             get => new(_minWidth, _minHeight);
@@ -378,6 +380,7 @@ namespace Robust.Client.UserInterface
         /// </remarks>
         /// <seealso cref="SetWidth"/>
         /// <seealso cref="SetHeight"/>
+        [Animatable]
         public Vector2 SetSize
         {
             get => new(_setWidth, _setHeight);
@@ -434,6 +437,7 @@ namespace Robust.Client.UserInterface
         /// Width component of <see cref="SetSize"/>.
         /// </summary>
         [ViewVariables(VVAccess.ReadWrite)]
+        [Animatable]
         public float SetWidth
         {
             get => _setWidth;
@@ -449,6 +453,7 @@ namespace Robust.Client.UserInterface
         /// Height component of <see cref="SetSize"/>.
         /// </summary>
         [ViewVariables(VVAccess.ReadWrite)]
+        [Animatable]
         public float SetHeight
         {
             get => _setHeight;

Robust.Client/UserInterface/Controls/Label.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Numerics;
 using System.Text;
@@ -44,6 +44,7 @@ namespace Robust.Client.UserInterface.Controls
         /// Thrown if <see cref="TextMemory"/> was set directly and there is no backing string instance to fetch.
         /// </exception>
         [ViewVariables]
+        [Animatable]
         public string? Text
         {
             get => _text ?? (_textMemory.Length > 0 ? throw new InvalidOperationException("Label uses TextMemory, cannot fetch string text.") : null);

Robust.Client/UserInterface/Controls/OSWindow.cs

@@ -144,7 +144,7 @@ namespace Robust.Client.UserInterface.Controls
             SetPositionFirst();
 
             // Resize the window by our UIScale
-            ClydeWindow.Size = new((int)(ClydeWindow.Size.X * UIScale), (int)(ClydeWindow.Size.Y * UIScale));
+            ClydeWindow.Size = new((int)(parameters.Width * UIScale), (int)(parameters.Height * UIScale));
             return ClydeWindow;
         }
 

Robust.Client/UserInterface/Controls/OutputPanel.cs

@@ -136,9 +136,14 @@ namespace Robust.Client.UserInterface.Controls
             AddMessage(msg);
         }
 
-        public void AddMessage(FormattedMessage message)
+        public void AddMessage(FormattedMessage message, Color? defaultColor = null)
         {
-            var entry = new RichTextEntry(message, this, _tagManager);
+            AddMessage(message, RichTextEntry.DefaultTags, defaultColor);
+        }
+
+        public void AddMessage(FormattedMessage message, Type[]? tagsAllowed, Color? defaultColor = null)
+        {
+            var entry = new RichTextEntry(message, this, _tagManager, tagsAllowed, defaultColor);
 
             entry.Update(_tagManager, _getFont(), _getContentBox().Width, UIScale);
 

Robust.Client/UserInterface/Controls/RichTextLabel.cs

@@ -39,6 +39,20 @@ namespace Robust.Client.UserInterface.Controls
             }
         }
 
+        /// <summary>
+        /// Gets or sets the markup string displayed by this control.
+        /// </summary>
+        /// <remarks>
+        /// <para>
+        /// This method converts the given string with <see cref="FormattedMessage.FromMarkupPermissive(string)"/>.
+        /// The original markup string is not kept,
+        /// so setting and then getting the function may provide a different result.
+        /// </para>
+        /// <para>
+        /// Unlike <see cref="M:SetMessage(FormattedMessage,Color?)"/>,
+        /// no tag whitelist will be set on the rendered message. Do not pass untrusted user input to this!
+        /// </para>
+        /// </remarks>
         public string? Text
         {
             get => _entry?.Message.ToMarkup();
@@ -47,7 +61,7 @@ namespace Robust.Client.UserInterface.Controls
                 if (value == null)
                     Clear();
                 else
-                    SetMessage(FormattedMessage.FromMarkupPermissive(value));
+                    SetMessage(FormattedMessage.FromMarkupPermissive(value), tagsAllowed: null);
             }
         }
 
@@ -67,11 +81,32 @@ namespace Robust.Client.UserInterface.Controls
             VerticalAlignment = VAlignment.Center;
         }
 
+        /// <summary>
+        /// Sets the formatted message displayed by this control.
+        /// </summary>
+        /// <param name="message">The message to display.</param>
+        /// <param name="defaultColor">If provided, the default color to use for this message rendering.</param>
+        /// <remarks>
+        /// This method sets the set of allowed tags to only include a small amount of safe formatting tags.
+        /// Use <see cref="M:SetMessage(FormattedMessage,Type[],Color?)"/> if this is not desired.
+        /// </remarks>
         public void SetMessage(FormattedMessage message, Color? defaultColor = null)
         {
             SetMessage(message, RichTextEntry.DefaultTags, defaultColor);
         }
 
+        /// <summary>
+        /// Sets the formatted message displayed by this control.
+        /// </summary>
+        /// <param name="message">The message to display.</param>
+        /// <param name="tagsAllowed">
+        /// The set of allowed markup tags that will be displayed.
+        /// If <c>null</c>, all tags are allowed.</param>
+        /// <param name="defaultColor">If provided, the default color to use for this message rendering.</param>
+        /// <remarks>
+        /// This method sets the set of allowed tags to only include a small amount of safe formatting tags.
+        /// Use <see cref="M:SetMessage(FormattedMessage,Type[],Color?)"/> if this is not desired.
+        /// </remarks>
         public void SetMessage(FormattedMessage message, Type[]? tagsAllowed, Color? defaultColor = null)
         {
             _entry?.RemoveControls();

Robust.Client/UserInterface/Controls/SpriteView.cs

@@ -170,6 +170,7 @@ namespace Robust.Client.UserInterface.Controls
 
             Entity = new(uid.Value, sprite, xform);
             NetEnt = EntMan.GetNetEntity(uid);
+            InvalidateMeasure();
         }
 
         protected override Vector2 MeasureOverride(Vector2 availableSize)

Robust.Client/UserInterface/Controls/TabContainer.cs

@@ -22,8 +22,10 @@ namespace Robust.Client.UserInterface.Controls
 
         private int _currentTab;
         private bool _tabsVisible = true;
-        // The right-most coordinate of each tab header
-        private List<float> _tabRight = new();
+
+        // the laid out tabs
+        private List<TabBox> _tabBoxes = new();
+        private float _enclosingTabHeight;
 
         public int CurrentTab
         {
@@ -146,41 +148,66 @@ namespace Robust.Client.UserInterface.Controls
             base.Draw(handle);
 
             // First, draw panel.
-            var headerSize = _getHeaderSize();
+            var headerSize = _enclosingTabHeight;
             var panel = _getPanel();
             var panelBox = new UIBox2(0, headerSize, PixelWidth, PixelHeight);
 
             panel?.Draw(handle, panelBox, UIScale);
 
             var font = _getFont();
-            var boxActive = _getTabBoxActive();
-            var boxInactive = _getTabBoxInactive();
             var fontColorActive = _getTabFontColorActive();
             var fontColorInactive = _getTabFontColorInactive();
 
-            var headerOffset = 0f;
+            // Then draw the tabs
+            foreach (var tabBox in _tabBoxes)
+            {
+                if (tabBox.Box is { } styleBox)
+                {
+                    styleBox.Draw(handle, tabBox.Bounding, UIScale);
+                }
 
-            _tabRight.Clear();
+                var baseLine = new Vector2(0, font.GetAscent(UIScale)) + tabBox.Content.TopLeft;
+                foreach (var rune in tabBox.Title.EnumerateRunes())
+                {
+                    if (!font.TryGetCharMetrics(rune, UIScale, out var metrics))
+                        continue;
+
+                    font.DrawChar(handle, rune, baseLine, UIScale, tabBox.Index == _currentTab ? fontColorActive : fontColorInactive);
+                    baseLine += new Vector2(metrics.Advance, 0);
+                }
+            }
+        }
+
+        private readonly record struct TabBox(UIBox2 Bounding, UIBox2 Content, StyleBox? Box, string Title, int Index);
+
+        private void CalculateTabBoxes(Vector2 availableSize)
+        {
+            availableSize *= UIScale;
+            var tabLeft = 0f;
+            var tabTop = 0f;
+            var tabHeight = 0f;
+
+            var font = _getFont();
+            var boxActive = _getTabBoxActive();
+            var boxInactive = _getTabBoxInactive();
+
+            _tabBoxes.Clear();
+
+            if (!_tabsVisible)
+                return;
 
-            // Then, draw the tabs.
             for (var i = 0; i < ChildCount; i++)
             {
                 if (!GetTabVisible(i))
-                {
-                    _tabRight.Add(headerOffset);
                     continue;
-                }
 
                 var title = GetActualTabTitle(i);
 
                 var titleLength = 0;
-                // Get string length.
                 foreach (var rune in title.EnumerateRunes())
                 {
                     if (!font.TryGetCharMetrics(rune, UIScale, out var metrics))
-                    {
                         continue;
-                    }
 
                     titleLength += metrics.Advance;
                 }
@@ -188,50 +215,57 @@ namespace Robust.Client.UserInterface.Controls
                 var active = _currentTab == i;
                 var box = active ? boxActive : boxInactive;
 
-                UIBox2 contentBox;
-                var topLeft = new Vector2(headerOffset, 0);
+                var topLeft = new Vector2(tabLeft, tabTop);
                 var size = new Vector2(titleLength, font.GetHeight(UIScale));
-                float boxAdvance;
 
                 if (box != null)
                 {
-                    var drawBox = box.GetEnvelopBox(topLeft, size, UIScale);
-                    boxAdvance = drawBox.Width;
-                    box.Draw(handle, drawBox, UIScale);
-                    contentBox = box.GetContentBox(drawBox, UIScale);
+                    size = box.GetEnvelopBox(topLeft, size, UIScale).Size;
+                }
+
+                if (tabLeft + size.X > availableSize.X)
+                {
+                    tabLeft = 0;
+                    tabTop += tabHeight;
+                    tabHeight = 0;
+                }
+
+                topLeft = new(tabLeft, tabTop);
+                size = new(titleLength, font.GetHeight(UIScale));
+
+                UIBox2 boundingBox;
+                UIBox2 contentBox;
+                if (box != null)
+                {
+                    boundingBox = box.GetEnvelopBox(topLeft, size, UIScale);
+                    contentBox = box.GetContentBox(boundingBox, UIScale);
                 }
                 else
                 {
-                    boxAdvance = size.X;
                     contentBox = UIBox2.FromDimensions(topLeft, size);
+                    boundingBox = contentBox;
                 }
 
-                var baseLine = new Vector2(0, font.GetAscent(UIScale)) + contentBox.TopLeft;
-
-                foreach (var rune in title.EnumerateRunes())
-                {
-                    if (!font.TryGetCharMetrics(rune, UIScale, out var metrics))
-                    {
-                        continue;
-                    }
-
-                    font.DrawChar(handle, rune, baseLine, UIScale, active ? fontColorActive : fontColorInactive);
-                    baseLine += new Vector2(metrics.Advance, 0);
-                }
-
-                headerOffset += boxAdvance;
-                // Remember the right-most point of this tab, for testing clicked areas
-                _tabRight.Add(headerOffset);
+                tabLeft += boundingBox.Size.X;
+                tabHeight = Math.Max(tabHeight, boundingBox.Size.Y);
+                _tabBoxes.Add(new(boundingBox, contentBox, box, title, i));
             }
+
+            if (Math.Abs(_enclosingTabHeight - (tabTop + tabHeight)) >= 0.1)
+            {
+                InvalidateArrange();
+            }
+            _enclosingTabHeight = tabTop + tabHeight;
         }
 
         protected override Vector2 MeasureOverride(Vector2 availableSize)
         {
+            CalculateTabBoxes(availableSize);
             var headerSize = Vector2.Zero;
 
             if (TabsVisible)
             {
-                headerSize = new Vector2(0, _getHeaderSize() / UIScale);
+                headerSize = new Vector2(0, _enclosingTabHeight / UIScale);
             }
 
             var panel = _getPanel();
@@ -254,12 +288,13 @@ namespace Robust.Client.UserInterface.Controls
 
         protected override Vector2 ArrangeOverride(Vector2 finalSize)
         {
+            CalculateTabBoxes(finalSize);
             if (ChildCount == 0 || _currentTab >= ChildCount)
             {
                 return finalSize;
             }
 
-            var headerSize = _getHeaderSize();
+            var headerSize = (int)_enclosingTabHeight;
             var panel = _getPanel();
             var contentBox = new UIBox2i(0, headerSize, (int) (finalSize.X * UIScale), (int) (finalSize.Y * UIScale));
             if (panel != null)
@@ -283,50 +318,23 @@ namespace Robust.Client.UserInterface.Controls
             }
 
             // Outside of header size, ignore.
-            if (args.RelativePixelPosition.Y < 0 || args.RelativePixelPosition.Y > _getHeaderSize())
+            if (args.RelativePixelPosition.Y < 0 || args.RelativePixelPosition.Y > _enclosingTabHeight)
             {
                 return;
             }
 
             args.Handle();
 
-            var relX = args.RelativePixelPosition.X;
-            float tabLeft = 0;
-            for (var i = 0; i < ChildCount; i++)
+            foreach (var box in _tabBoxes)
             {
-                if (relX > tabLeft && relX <= _tabRight[i])
+                if (box.Bounding.Contains(args.RelativePixelPosition))
                 {
-                    CurrentTab = i;
+                    CurrentTab = box.Index;
                     return;
                 }
-
-                // Next tab starts here
-                tabLeft = _tabRight[i];
             }
         }
 
-        // Returns the size of the header, in real pixels
-        [System.Diagnostics.Contracts.Pure]
-        private int _getHeaderSize()
-        {
-            var headerSize = 0;
-
-            if (TabsVisible)
-            {
-                var active = _getTabBoxActive();
-                var inactive = _getTabBoxInactive();
-                var font = _getFont();
-
-                var activeSize = (active?.MinimumSize ?? Vector2.Zero) * UIScale;
-                var inactiveSize = (inactive?.MinimumSize ?? Vector2.Zero) * UIScale;
-
-                headerSize = (int) MathF.Max(activeSize.Y, inactiveSize.Y);
-                headerSize += font.GetHeight(UIScale);
-            }
-
-            return headerSize;
-        }
-
         [System.Diagnostics.Contracts.Pure]
         private StyleBox? _getTabBoxActive()
         {

Robust.Client/UserInterface/IRawInputControl.cs

@@ -35,13 +35,15 @@ namespace Robust.Client.UserInterface
         public readonly int ScanCode;
         public readonly RawKeyAction Action;
         public readonly Vector2i MouseRelative;
+        public readonly ushort RawCode;
 
-        public GuiRawKeyEvent(Keyboard.Key key, int scanCode, RawKeyAction action, Vector2i mouseRelative)
+        public GuiRawKeyEvent(Keyboard.Key key, int scanCode, RawKeyAction action, Vector2i mouseRelative, ushort rawCode)
         {
             Key = key;
             ScanCode = scanCode;
             Action = action;
             MouseRelative = mouseRelative;
+            RawCode = rawCode;
         }
     }
 

Robust.Client/Utility/ClientDllMap.cs

@@ -14,15 +14,6 @@ namespace Robust.Client.Utility
         {
             NativeLibrary.SetDllImportResolver(typeof(ClientDllMap).Assembly, (name, assembly, path) =>
             {
-                if (name == "swnfd.dll")
-                {
-#if LINUX || FREEBSD
-                    return NativeLibrary.Load("libswnfd.so", assembly, path);
-#elif MACOS
-                    return NativeLibrary.Load("libswnfd.dylib", assembly, path);
-#endif
-                }
-
                 if (name == "libEGL.dll")
                 {
 #if LINUX || FREEBSD

Robust.Client/Utility/ReloadManager.cs

@@ -20,9 +20,9 @@ internal sealed class ReloadManager : IReloadManager
     [Dependency] private readonly IConfigurationManager _cfg = default!;
     [Dependency] private readonly ILogManager _logMan = default!;
     [Dependency] private readonly IResourceManagerInternal _res = default!;
-#pragma warning disable CS0414
+#if TOOLS
     [Dependency] private readonly ITaskManager _tasks = default!;
-#pragma warning restore CS0414
+#endif
 
     private readonly TimeSpan _reloadDelay = TimeSpan.FromMilliseconds(10);
     private CancellationTokenSource _reloadToken = new();

Robust.Client/ViewVariables/ViewVariableControlFactory.cs

@@ -56,7 +56,7 @@ internal sealed class ViewVariableControlFactory : IViewVariableControlFactory
         RegisterForType<TimeSpan>(_ =>  new VVPropEditorTimeSpan());
 
         RegisterWithCondition(
-            type => type != typeof(ViewVariablesBlobMembers.ServerValueTypeToken) && !type.IsValueType,
+            type => type != typeof(ViewVariablesBlobMembers.ServerValueTypeToken),
             _ => new VVPropEditorReference()
         );
         RegisterWithCondition(

Robust.Server.Testing/RobustServerSimulation.cs

@@ -9,11 +9,13 @@ using Robust.Server.Debugging;
 using Robust.Server.GameObjects;
 using Robust.Server.GameStates;
 using Robust.Server.Localization;
+using Robust.Server.Network.Transfer;
 using Robust.Server.Physics;
 using Robust.Server.Player;
 using Robust.Server.Prototypes;
 using Robust.Server.Reflection;
 using Robust.Server.Replays;
+using Robust.Server.ServerStatus;
 using Robust.Shared;
 using Robust.Shared.Asynchronous;
 using Robust.Shared.Configuration;
@@ -28,6 +30,7 @@ using Robust.Shared.Log;
 using Robust.Shared.Map;
 using Robust.Shared.Map.Components;
 using Robust.Shared.Network;
+using Robust.Shared.Network.Transfer;
 using Robust.Shared.Physics;
 using Robust.Shared.Physics.Collision;
 using Robust.Shared.Physics.Components;
@@ -198,6 +201,9 @@ namespace Robust.UnitTesting.Server
             container.Register<HttpClientHolder>();
             container.Register<IHttpClientHolder, HttpClientHolder>();
             container.Register<IHWId, DummyHWId>();
+            container.Register<IServerNetManager, NetManager>();
+            container.Register<IStatusHost, StatusHost>();
+            container.Register<ITransferManager, ServerTransferManager>();
 
             var realReflection = new ServerReflectionManager();
             realReflection.LoadAssemblies(new List<Assembly>(2)
@@ -262,7 +268,6 @@ namespace Robust.UnitTesting.Server
 
             // I just wanted to load pvs system
             container.Register<IServerEntityManager, ServerEntityManager>();
-            container.Register<IServerNetManager, NetManager>();
             // god help you if you actually need to test pvs functions
             container.RegisterInstance<IPlayerManager>(new Mock<IPlayerManager>().Object);
             container.RegisterInstance<ISharedPlayerManager>(new Mock<ISharedPlayerManager>().Object);

Robust.Server/BaseServer.cs

@@ -9,6 +9,7 @@ using Robust.Server.DataMetrics;
 using Robust.Server.GameObjects;
 using Robust.Server.GameStates;
 using Robust.Server.Log;
+using Robust.Server.Network.Transfer;
 using Robust.Server.Placement;
 using Robust.Server.Player;
 using Robust.Server.Scripting;
@@ -29,6 +30,7 @@ using Robust.Shared.Localization;
 using Robust.Shared.Log;
 using Robust.Shared.Map;
 using Robust.Shared.Network;
+using Robust.Shared.Network.Transfer;
 using Robust.Shared.Player;
 using Robust.Shared.Profiling;
 using Robust.Shared.Prototypes;
@@ -107,6 +109,8 @@ namespace Robust.Server
         [Dependency] private readonly UploadedContentManager _uploadedContMan = default!;
         [Dependency] private readonly NetworkResourceManager _netResMan = default!;
         [Dependency] private readonly IReflectionManager _refMan = default!;
+        [Dependency] private readonly ITransferManager _transfer = default!;
+        [Dependency] private readonly ServerTransferTestManager _transferTest = default!;
 
         private readonly Stopwatch _uptimeStopwatch = new();
 
@@ -275,6 +279,7 @@ namespace Robust.Server
 
             // Load metrics really early so that we can profile startup times in the future maybe.
             _metricsManager.Initialize();
+            _prof.Initialize();
 
             try
             {
@@ -293,6 +298,9 @@ namespace Robust.Server
                 return true;
             }
 
+            _transfer.Initialize();
+            _transferTest.Initialize();
+
             var dataDir = Options.LoadConfigAndUserData
                 ? _commandLineArgs?.DataDir ?? PathHelpers.ExecutableRelativeFile("data")
                 : null;
@@ -303,8 +311,14 @@ namespace Robust.Server
             var mountOptions = _commandLineArgs != null
                 ? MountOptions.Merge(_commandLineArgs.MountOptions, Options.MountOptions) : Options.MountOptions;
 
+            var startType = ContentStart ? StartType.Content : StartType.Engine;
+#if FULL_RELEASE
+            if (Options.ResourceMountDisabled)
+                startType = StartType.Loader;
+#endif
+
             ProgramShared.DoMounts(_resources, mountOptions, Options.ContentBuildDirectory, Options.AssemblyDirectory,
-                Options.LoadContentResources, Options.ResourceMountDisabled, ContentStart);
+                Options.LoadContentResources, startType);
 
             // When the game is ran with the startup executable being content,
             // we have to disable the separate load context.
@@ -767,6 +781,8 @@ namespace Robust.Server
 
             _modLoader.BroadcastUpdate(ModUpdateLevel.FramePostEngine, frameEventArgs);
 
+            _transfer.FrameUpdate();
+
             _metricsManager.FrameUpdate();
         }
 

Robust.Server/Console/ServerConsoleHost.cs

@@ -9,6 +9,7 @@ using Robust.Shared.IoC;
 using Robust.Shared.Network;
 using Robust.Shared.Network.Messages;
 using Robust.Shared.Player;
+using Robust.Shared.Profiling;
 using Robust.Shared.Toolshed;
 using Robust.Shared.Utility;
 
@@ -22,6 +23,7 @@ namespace Robust.Server.Console
         [Dependency] private readonly IPlayerManager _players = default!;
         [Dependency] private readonly ISystemConsoleManager _systemConsole = default!;
         [Dependency] private readonly ToolshedManager _toolshed = default!;
+        [Dependency] private readonly ProfManager _prof = default!;
 
         public ServerConsoleHost() : base(isServer: true) {}
 
@@ -108,7 +110,8 @@ namespace Robust.Server.Console
                 if (args.Count == 0)
                     return;
 
-                string? cmdName = args[0];
+                var cmdName = args[0];
+                using var _ = _prof.Group(cmdName);
 
                 if (RegisteredCommands.TryGetValue(cmdName, out var conCmd)) // command registered
                 {

Robust.Server/Network/Transfer/ServerTransferImplWebSocket.cs

@@ -0,0 +1,122 @@
+using System;
+using System.Net;
+using System.Security.Cryptography;
+using System.Threading;
+using System.Threading.Tasks;
+using Robust.Server.ServerStatus;
+using Robust.Shared;
+using Robust.Shared.Configuration;
+using Robust.Shared.Log;
+using Robust.Shared.Network;
+using Robust.Shared.Network.Messages.Transfer;
+using Robust.Shared.Network.Transfer;
+using Robust.Shared.Utility;
+
+namespace Robust.Server.Network.Transfer;
+
+internal sealed class ServerTransferImplWebSocket : TransferImplWebSocket
+{
+    private readonly IConfigurationManager _cfg;
+    private readonly INetManager _netManager;
+    private readonly SemaphoreSlim _apiLock = new(1, 1);
+    private readonly TaskCompletionSource _connectTcs = new();
+
+    // To authenticate the client doing the HTTP request,
+    // we ask that they provide a key we gave them via Lidgren traffic.
+    public byte[]? Key;
+
+    public ServerTransferImplWebSocket(
+        ISawmill sawmill,
+        BaseTransferManager parent,
+        IConfigurationManager cfg,
+        INetManager netManager,
+        INetChannel channel)
+        : base(sawmill, parent, channel)
+    {
+        _cfg = cfg;
+        _netManager = netManager;
+    }
+
+    public override Task ServerInit()
+    {
+        Key = RandomNumberGenerator.GetBytes(RandomKeyBytes);
+
+        var uriBuilder = new UriBuilder(string.Concat(
+            _cfg.GetCVar(CVars.TransferHttpEndpoint).TrimEnd("/"),
+            ServerTransferManager.TransferApiUrl));
+
+        uriBuilder.Scheme = uriBuilder.Scheme switch
+        {
+            "http" => "ws",
+            "https" => "wss",
+            _ => throw new InvalidOperationException($"Invalid API endpoint scheme: {uriBuilder.Scheme}")
+        };
+
+        var url = uriBuilder.ToString();
+
+        Sawmill.Verbose($"Transfer API URL is '{url}'");
+
+        var initMsg = new MsgTransferInit();
+        initMsg.HttpInfo = (url, Key);
+
+        _netManager.ServerSendMessage(initMsg, Channel);
+
+        return _connectTcs.Task;
+    }
+
+    public override Task ClientInit(CancellationToken cancel)
+    {
+        throw new NotSupportedException();
+    }
+
+    public async Task HandleApiRequest(NetUserId userId, IStatusHandlerContext context)
+    {
+        using var _ = await _apiLock.WaitGuardAsync();
+
+        if (Key == null)
+        {
+            Sawmill.Warning($"HTTP request failed: UserID '{userId}' tried to connect twice");
+            await context.RespondErrorAsync(HttpStatusCode.BadRequest);
+            return;
+        }
+
+        if (!context.RequestHeaders.TryGetValue(KeyHeaderName, out var keyValue) || keyValue is not [{ } keyValueStr])
+        {
+            await context.RespondErrorAsync(HttpStatusCode.BadRequest);
+            return;
+        }
+
+        var buf = new byte[RandomKeyBytes];
+
+        if (!Convert.TryFromBase64String(keyValueStr, buf, out var written) || written != RandomKeyBytes)
+        {
+            Sawmill.Verbose("HTTP request failed: key is not valid base64 or wrong length");
+            await context.RespondErrorAsync(HttpStatusCode.BadRequest);
+            return;
+        }
+
+        if (!CryptographicOperations.FixedTimeEquals(buf, Key))
+        {
+            Sawmill.Warning("HTTP request failed: key is wrong");
+            await context.RespondErrorAsync(HttpStatusCode.Unauthorized);
+            return;
+        }
+
+        Sawmill.Debug("Client connect to transfer WS channel: {UserId}", userId);
+
+        WebSocket = await context.AcceptWebSocketAsync();
+
+        // We've connected.
+        // Clear key so this can't be reconnected to.
+        Key = null;
+
+        _connectTcs.TrySetResult();
+
+        ReadThread();
+    }
+
+    public override void Dispose()
+    {
+        _connectTcs.TrySetCanceled();
+    }
+}

Robust.Server/Network/Transfer/ServerTransferManager.cs

@@ -0,0 +1,171 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Net;
+using System.Threading.Tasks;
+using Robust.Server.ServerStatus;
+using Robust.Shared;
+using Robust.Shared.Asynchronous;
+using Robust.Shared.Configuration;
+using Robust.Shared.Log;
+using Robust.Shared.Network;
+using Robust.Shared.Network.Messages.Transfer;
+using Robust.Shared.Network.Transfer;
+
+namespace Robust.Server.Network.Transfer;
+
+internal sealed class ServerTransferManager : BaseTransferManager, ITransferManager
+{
+    internal const string TransferApiUrl = "/rt_transfer_init";
+
+    private readonly IConfigurationManager _cfg;
+    private readonly IStatusHost _statusHost;
+    private readonly IServerNetManager _netManager;
+
+    private readonly Dictionary<NetUserId, Player> _onlinePlayers = new();
+
+    internal ServerTransferManager(IConfigurationManager cfg, IStatusHost statusHost, IServerNetManager netManager, ILogManager logManager, ITaskManager taskManager)
+        : base(logManager, NetMessageAccept.Server, taskManager)
+    {
+        _cfg = cfg;
+        _statusHost = statusHost;
+        _netManager = netManager;
+    }
+
+    public void Initialize()
+    {
+        _netManager.RegisterNetMessage<MsgTransferInit>();
+        _netManager.RegisterNetMessage<MsgTransferData>(RxTransferData, NetMessageAccept.Server | NetMessageAccept.Handshake);
+        _netManager.RegisterNetMessage<MsgTransferAckInit>(RxTransferAckInit, NetMessageAccept.Server | NetMessageAccept.Handshake);
+
+        _statusHost.AddHandler(HandleRequest);
+
+        _netManager.Disconnect += NetManagerOnDisconnect;
+    }
+
+    private void RxTransferData(MsgTransferData message)
+    {
+        if (!_onlinePlayers.TryGetValue(message.MsgChannel.UserId, out var player)
+            || player.Impl is not TransferImplLidgren lidgren)
+        {
+            message.MsgChannel.Disconnect("Not lidgren");
+            return;
+        }
+
+        lidgren.ReceiveData(message);
+    }
+
+    private void RxTransferAckInit(MsgTransferAckInit message)
+    {
+        if (!_onlinePlayers.TryGetValue(message.MsgChannel.UserId, out var player)
+            || player.Impl is not TransferImplLidgren lidgren)
+        {
+            message.MsgChannel.Disconnect("Not lidgren");
+            return;
+        }
+
+        lidgren.ReceiveInitAck();
+    }
+
+    public Stream StartTransfer(INetChannel channel, TransferStartInfo startInfo)
+    {
+        if (!_onlinePlayers.TryGetValue(channel.UserId, out var player))
+            throw new InvalidOperationException("Player is not connected yet!");
+
+        return player.Impl.StartTransfer(startInfo);
+    }
+
+    private async Task<bool> HandleRequest(IStatusHandlerContext context)
+    {
+        if (context.Url.AbsolutePath != TransferApiUrl)
+            return false;
+
+        if (!context.IsWebSocketRequest)
+        {
+            Sawmill.Verbose("HTTP request failed: not a websocket request");
+            await context.RespondErrorAsync(HttpStatusCode.BadRequest);
+            return true;
+        }
+
+        if (!context.RequestHeaders.TryGetValue(TransferImplWebSocket.UserIdHeaderName, out var userIdValue)
+            || userIdValue.Count != 1)
+        {
+            Sawmill.Verbose("HTTP request failed: missing RT-UserId");
+            await context.RespondErrorAsync(HttpStatusCode.BadRequest);
+            return true;
+        }
+
+        if (!Guid.TryParse(userIdValue[0], out var userId))
+        {
+            Sawmill.Verbose($"HTTP request failed: UserID '{userId}' invalid");
+            await context.RespondErrorAsync(HttpStatusCode.BadRequest);
+            return true;
+        }
+
+        if (!_onlinePlayers.TryGetValue(new NetUserId(userId), out var player))
+        {
+            Sawmill.Warning($"HTTP request failed: UserID '{userId}' not online");
+            await context.RespondErrorAsync(HttpStatusCode.BadRequest);
+            return true;
+        }
+
+        if (player.Impl is not ServerTransferImplWebSocket serverWs)
+        {
+            Sawmill.Warning($"HTTP request failed: UserID '{userId}' is not using websocket transfer");
+            await context.RespondErrorAsync(HttpStatusCode.Unauthorized);
+            return true;
+        }
+
+        await serverWs.HandleApiRequest(new NetUserId(userId), context);
+        return true;
+    }
+
+    public async Task ServerHandshake(INetChannel channel)
+    {
+        if (_onlinePlayers.ContainsKey(channel.UserId))
+            throw new InvalidOperationException("We already have data for this user??");
+
+        var transferHttpEnabled = _cfg.GetCVar(CVars.TransferHttp);
+
+        BaseTransferImpl impl;
+        if (transferHttpEnabled)
+        {
+            impl = new ServerTransferImplWebSocket(Sawmill, this, _cfg, _netManager, channel);
+        }
+        else
+        {
+            impl = new TransferImplLidgren(Sawmill, channel, this, _netManager);
+        }
+
+        impl.MaxChannelCount = _cfg.GetCVar(CVars.TransferStreamLimit);
+
+        var datum = new Player
+        {
+            Impl = impl,
+        };
+
+        _onlinePlayers.Add(channel.UserId, datum);
+
+        await impl.ServerInit();
+    }
+
+    public event Action ClientHandshakeComplete
+    {
+        add { }
+        remove { }
+    }
+
+    private void NetManagerOnDisconnect(object? sender, NetDisconnectedArgs e)
+    {
+        if (!_onlinePlayers.Remove(e.Channel.UserId, out var player))
+            return;
+
+        Sawmill.Debug("Cleaning up connection for channel {Player} that disconnected", e.Channel);
+        player.Impl.Dispose();
+    }
+
+    private sealed class Player
+    {
+        public required BaseTransferImpl Impl;
+    }
+}

Robust.Server/Network/Transfer/ServerTransferTestManager.cs

@@ -0,0 +1,23 @@
+using Robust.Server.Console;
+using Robust.Server.Player;
+using Robust.Shared.Log;
+using Robust.Shared.Network;
+using Robust.Shared.Network.Transfer;
+
+namespace Robust.Server.Network.Transfer;
+
+internal sealed class ServerTransferTestManager(
+    ITransferManager manager,
+    ILogManager logManager,
+    IConGroupController controller,
+    IPlayerManager playerManager)
+    : TransferTestManager(manager, logManager)
+{
+    protected override bool PermissionCheck(INetChannel channel)
+    {
+        if (!playerManager.TryGetSessionByChannel(channel, out var session))
+            return false;
+
+        return controller.CanCommand(session, TransferTestCommand.CommandKey);
+    }
+}

Robust.Server/Placement/PlacementManager.cs

@@ -217,6 +217,10 @@ namespace Robust.Server.Placement
             }
         }
 
+        /// <summary>
+        /// Deletes any existing entity.
+        /// </summary>
+        /// <param name="msg"></param>
         private void HandleEntRemoveReq(MsgPlacement msg)
         {
             //TODO: Some form of admin check
@@ -225,26 +229,61 @@ namespace Robust.Server.Placement
             if (!_entityManager.EntityExists(entity))
                 return;
 
-            var placementEraseEvent = new PlacementEntityEvent(entity, _entityManager.GetComponent<TransformComponent>(entity).Coordinates, PlacementEventAction.Erase, msg.MsgChannel.UserId);
+            var placementEraseEvent = new PlacementEntityEvent(entity,
+                _entityManager.GetComponent<TransformComponent>(entity).Coordinates,
+                PlacementEventAction.Erase,
+                msg.MsgChannel.UserId);
+
             _entityManager.EventBus.RaiseEvent(EventSource.Local, placementEraseEvent);
             _entityManager.DeleteEntity(entity);
         }
 
+        /// <summary>
+        /// Deletes almost any existing entity within a selection box.
+        /// </summary>
+        /// <param name="msg"></param>
         private void HandleRectRemoveReq(MsgPlacement msg)
         {
-            EntityCoordinates start = _entityManager.GetCoordinates(msg.NetCoordinates);
-            Vector2 rectSize = msg.RectSize;
-            foreach (var entity in _lookup.GetEntitiesIntersecting(_xformSystem.GetMapId(start),
-                new Box2(start.Position, start.Position + rectSize)))
+            var start = _entityManager.GetCoordinates(msg.NetCoordinates);
+            var rectSize = msg.RectSize;
+
+            foreach (var entity in _lookup.GetEntitiesIntersecting(_xformSystem.GetMapId(start), new Box2(start.Position, start.Position + rectSize)))
             {
-                if (_entityManager.Deleted(entity) ||
-                    _entityManager.HasComponent<MapGridComponent>(entity) ||
-                    _entityManager.HasComponent<ActorComponent>(entity))
-                {
+                if (_entityManager.Deleted(entity)
+                    || _entityManager.HasComponent<MapGridComponent>(entity)
+                    || _entityManager.HasComponent<ActorComponent>(entity))
                     continue;
+
+                var xform = _entityManager.GetComponent<TransformComponent>(entity);
+                var parent = xform.ParentUid;
+                var isChildOfActor = false;
+
+                while (parent.IsValid())
+                {
+                    if (_entityManager.HasComponent<ActorComponent>(parent))
+                    {
+                        isChildOfActor = true;
+                        break;
+                    }
+
+                    if (_entityManager.TryGetComponent<TransformComponent>(parent, out var parentXform))
+                    {
+                        parent = parentXform.ParentUid;
+                    }
+                    else
+                    {
+                        break;
+                    }
                 }
 
-                var placementEraseEvent = new PlacementEntityEvent(entity, _entityManager.GetComponent<TransformComponent>(entity).Coordinates, PlacementEventAction.Erase, msg.MsgChannel.UserId);
+                if (isChildOfActor)
+                    continue;
+
+                var placementEraseEvent = new PlacementEntityEvent(entity,
+                    _entityManager.GetComponent<TransformComponent>(entity).Coordinates,
+                    PlacementEventAction.Erase,
+                    msg.MsgChannel.UserId);
+                
                 _entityManager.EventBus.RaiseEvent(EventSource.Local, placementEraseEvent);
                 _entityManager.DeleteEntity(entity);
             }

Robust.Server/Player/IPlayerManager.cs

@@ -1,4 +1,5 @@
 using Robust.Shared.Input;
+using Robust.Shared.Network;
 using Robust.Shared.Player;
 
 namespace Robust.Server.Player;
@@ -10,4 +11,6 @@ namespace Robust.Server.Player;
 public interface IPlayerManager : ISharedPlayerManager
 {
     BoundKeyMap KeyMap { get; }
+
+    internal void MarkPlayerResourcesSent(INetChannel channel);
 }

Robust.Server/Player/PlayerManager.cs

@@ -120,13 +120,34 @@ namespace Robust.Server.Player
         private void HandlePlayerListReq(MsgPlayerListReq message)
         {
             var channel = message.MsgChannel;
+            var session = (CommonSession) GetSessionByChannel(channel);
+            session.InitialPlayerListReqDone = true;
+
+            if (!session.InitialResourcesDone)
+                return;
+
+            SendPlayerList(channel, session);
+        }
+
+        public void MarkPlayerResourcesSent(INetChannel channel)
+        {
+            var session = (CommonSession) GetSessionByChannel(channel);
+            session.InitialResourcesDone = true;
+
+            if (!session.InitialPlayerListReqDone)
+                return;
+
+            SendPlayerList(channel, session);
+        }
+
+        private void SendPlayerList(INetChannel channel, CommonSession session)
+        {
             var players = Sessions;
             var netMsg = new MsgPlayerList();
 
             // client session is complete, set their status accordingly.
             // This is done before the packet is built, so that the client
             // can see themselves Connected.
-            var session = GetSessionByChannel(channel);
             session.ConnectedTime = DateTime.UtcNow;
             SetStatus(session, SessionStatus.Connected);
 

Robust.Server/Prototypes/ServerPrototypeManager.cs

@@ -13,10 +13,10 @@ namespace Robust.Server.Prototypes
 {
     public sealed class ServerPrototypeManager : PrototypeManager
     {
-#pragma warning disable CS0414
+#if TOOLS
         [Dependency] private readonly IPlayerManager _playerManager = default!;
         [Dependency] private readonly IConGroupController _conGroups = default!;
-#pragma warning restore CS0414
+#endif
         [Dependency] private readonly INetManager _netManager = default!;
         [Dependency] private readonly IBaseServerInternal _server = default!;
 

Robust.Server/ServerIoC.cs

@@ -5,6 +5,7 @@ using Robust.Server.DataMetrics;
 using Robust.Server.GameObjects;
 using Robust.Server.GameStates;
 using Robust.Server.Localization;
+using Robust.Server.Network.Transfer;
 using Robust.Server.Placement;
 using Robust.Server.Player;
 using Robust.Server.Prototypes;
@@ -25,6 +26,7 @@ using Robust.Shared.IoC;
 using Robust.Shared.Localization;
 using Robust.Shared.Map;
 using Robust.Shared.Network;
+using Robust.Shared.Network.Transfer;
 using Robust.Shared.Player;
 using Robust.Shared.Prototypes;
 using Robust.Shared.Reflection;
@@ -102,6 +104,8 @@ namespace Robust.Server
             deps.Register<IHWId, DummyHWId>();
             deps.Register<ILocalizationManager, ServerLocalizationManager>();
             deps.Register<ILocalizationManagerInternal, ServerLocalizationManager>();
+            deps.Register<ITransferManager, ServerTransferManager>();
+            deps.Register<ServerTransferTestManager>();
         }
     }
 }

Robust.Server/ServerStatus/IStatusHandlerContext.cs

@@ -3,6 +3,7 @@ using System.Collections.Generic;
 using System.IO;
 using System.Net;
 using System.Net.Http;
+using System.Net.WebSockets;
 using System.Threading.Tasks;
 using Microsoft.Extensions.Primitives;
 
@@ -25,6 +26,8 @@ namespace Robust.Server.ServerStatus
         IDictionary<string, string> ResponseHeaders { get; }
         bool KeepAlive { get; set; }
 
+        bool IsWebSocketRequest { get; }
+
         Task<T?> RequestBodyJsonAsync<T>();
 
         Task RespondNoContentAsync();
@@ -54,5 +57,7 @@ namespace Robust.Server.ServerStatus
         Task RespondJsonAsync(object jsonData, HttpStatusCode code = HttpStatusCode.OK);
 
         Task<Stream> RespondStreamAsync(HttpStatusCode code = HttpStatusCode.OK);
+
+        Task<WebSocket> AcceptWebSocketAsync();
     }
 }

Robust.Server/ServerStatus/StatusHost.cs

@@ -14,6 +14,7 @@ using System.Linq;
 using System.Net;
 using System.Net.Http;
 using System.Net.Mime;
+using System.Net.WebSockets;
 using System.Text.Json;
 using System.Text.Json.Nodes;
 using System.Text.Json.Serialization;
@@ -242,6 +243,7 @@ namespace Robust.Server.ServerStatus
             public Uri Url => _context.Request.Url!;
             public bool IsGetLike => RequestMethod == HttpMethod.Head || RequestMethod == HttpMethod.Get;
             public IReadOnlyDictionary<string, StringValues> RequestHeaders { get; }
+            public bool IsWebSocketRequest => _context.Request.IsWebSocketRequest;
 
             public bool KeepAlive
             {
@@ -353,6 +355,12 @@ namespace Robust.Server.ServerStatus
                 return Task.FromResult(_context.Response.OutputStream);
             }
 
+            public async Task<WebSocket> AcceptWebSocketAsync()
+            {
+                var context = await _context.AcceptWebSocketAsync(null);
+                return context.WebSocket;
+            }
+
             private void RespondShared()
             {
                 foreach (var (header, value) in _responseHeaders)

Robust.Server/Upload/NetworkResourceManager.cs

@@ -1,77 +1,153 @@
 using System;
+using System.Buffers.Binary;
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.Linq;
 using Robust.Server.Console;
 using Robust.Server.Player;
 using Robust.Shared;
 using Robust.Shared.Configuration;
 using Robust.Shared.IoC;
 using Robust.Shared.Network;
+using Robust.Shared.Network.Transfer;
 using Robust.Shared.Player;
 using Robust.Shared.Upload;
+using Robust.Shared.Utility;
 using Robust.Shared.ViewVariables;
 
 namespace Robust.Server.Upload;
 
+public sealed class NetworkResourcesUploadedEvent
+{
+    public ICommonSession Session { get; }
+    public ImmutableArray<(ResPath Relative, byte[] Data)> Files { get; }
+
+    internal NetworkResourcesUploadedEvent(ICommonSession session, ImmutableArray<(ResPath, byte[])> files)
+    {
+        Session = session;
+        Files = files;
+    }
+}
+
 public sealed class NetworkResourceManager : SharedNetworkResourceManager
 {
+    internal const int AckInitial = 1;
+
     [Dependency] private readonly IPlayerManager _playerManager = default!;
     [Dependency] private readonly IServerNetManager _serverNetManager = default!;
     [Dependency] private readonly IConfigurationManager _cfgManager = default!;
     [Dependency] private readonly IConGroupController _controller = default!;
 
+    [Obsolete("Use ResourcesUploaded instead")]
     public event Action<ICommonSession, NetworkResourceUploadMessage>? OnResourceUploaded;
+    public event Action<NetworkResourcesUploadedEvent>? ResourcesUploaded;
 
     [ViewVariables] public bool Enabled { get; private set; } = true;
     [ViewVariables] public float SizeLimit { get; private set; }
 
-    public override void Initialize()
+    internal event Action<INetChannel, int>? AckReceived;
+
+    internal override void Initialize()
     {
         base.Initialize();
 
+        TransferManager.RegisterTransferMessage(TransferKeyNetworkDownload);
+        TransferManager.RegisterTransferMessage(TransferKeyNetworkUpload, ReceiveUpload);
+
         _cfgManager.OnValueChanged(CVars.ResourceUploadingEnabled, value => Enabled = value, true);
         _cfgManager.OnValueChanged(CVars.ResourceUploadingLimitMb, value => SizeLimit = value, true);
+
+        _serverNetManager.RegisterNetMessage<NetworkResourceAckMessage>(RxAck);
     }
 
-    /// <summary>
-    ///     Callback for when a client attempts to upload a resource.
-    /// </summary>
-    /// <param name="msg"></param>
-    /// <exception cref="NotImplementedException"></exception>
-    protected override void ResourceUploadMsg(NetworkResourceUploadMessage msg)
+    private void RxAck(NetworkResourceAckMessage message)
+    {
+        AckReceived?.Invoke(message.MsgChannel, message.Key);
+    }
+
+    private async void ReceiveUpload(TransferReceivedEvent transfer)
     {
         // Do not allow uploading any new resources if it has been disabled.
         // Note: Any resources uploaded before being disabled will still be kept and sent.
         if (!Enabled)
+        {
+            transfer.Channel.Disconnect("Resource upload not enabled.");
             return;
+        }
 
-        if (!_playerManager.TryGetSessionByChannel(msg.MsgChannel, out var session))
+        if (!_playerManager.TryGetSessionByChannel(transfer.Channel, out var session))
+        {
+            transfer.Channel.Disconnect("Not in-game");
             return;
+        }
 
         if (!_controller.CanCommand(session, "uploadfile"))
+        {
+            transfer.Channel.Disconnect("Not authorized");
             return;
+        }
 
-        // Ensure the data is under the current size limit, if it's currently enabled.
-        if (SizeLimit > 0f && msg.Data.Length * BytesToMegabytes > SizeLimit)
-            return;
+        Sawmill.Verbose("Ingesting file uploads from {Session}", session);
 
-        base.ResourceUploadMsg(msg);
+        List<(ResPath Relative, byte[] Data)> ingested;
+        await using (var stream = transfer.DataStream)
+        {
+            ingested = await IngestFileStream(stream);
+        }
+
+        Sawmill.Verbose("Ingesting file uploads complete, distributing...");
 
-        // Now we broadcast the message!
         foreach (var channel in _serverNetManager.Channels)
         {
-            channel.SendMessage(msg);
+            SendToPlayer(channel, ingested);
         }
 
-        OnResourceUploaded?.Invoke(session, msg);
+#pragma warning disable CS0618 // Type or member is obsolete
+        if (OnResourceUploaded != null)
+        {
+            foreach (var (relative, data) in ingested)
+            {
+                OnResourceUploaded?.Invoke(session, new NetworkResourceUploadMessage
+                {
+                    MsgChannel = session.Channel,
+                    Data = data,
+                    RelativePath = relative
+                });
+            }
+        }
+#pragma warning restore CS0618 // Type or member is obsolete
+
+        ResourcesUploaded?.Invoke(new NetworkResourcesUploadedEvent(session, [..ingested]));
     }
 
-    internal void SendToNewUser(INetChannel channel)
+    protected override void ValidateUpload(uint size)
     {
-        foreach (var (path, data) in ContentRoot.GetAllFiles())
-        {
-            var msg = new NetworkResourceUploadMessage();
-            msg.RelativePath = path;
-            msg.Data = data;
-            channel.SendMessage(msg);
-        }
+        if (SizeLimit > 0f && size * BytesToMegabytes > SizeLimit)
+            throw new Exception("File upload too large!");
+    }
+
+    internal bool SendToNewUser(INetChannel channel)
+    {
+        var allFiles = ContentRoot.GetAllFiles().ToList();
+        if (allFiles.Count == 0)
+            return false;
+
+        SendToPlayer(channel, allFiles, AckInitial);
+        return true;
+    }
+
+    private async void SendToPlayer(INetChannel channel, List<(ResPath Relative, byte[] Data)> files, int ack = 0)
+    {
+        await using var stream = TransferManager.StartTransfer(channel,
+            new TransferStartInfo
+            {
+                MessageKey = TransferKeyNetworkDownload
+            });
+
+        var ackBytes = new byte[4];
+        BinaryPrimitives.WriteInt32LittleEndian(ackBytes, ack);
+        await stream.WriteAsync(ackBytes);
+
+        await WriteFileStream(stream, files);
     }
 }

Robust.Server/Upload/UploadedContentManager.cs

@@ -1,4 +1,5 @@
-using Robust.Shared.IoC;
+using Robust.Server.Player;
+using Robust.Shared.IoC;
 using Robust.Shared.Network;
 
 namespace Robust.Server.Upload;
@@ -9,20 +10,36 @@ namespace Robust.Server.Upload;
 internal sealed class UploadedContentManager
 {
     [Dependency] private readonly IServerNetManager _netManager = default!;
+    [Dependency] private readonly IPlayerManager _playerManager = default!;
     [Dependency] private readonly GamePrototypeLoadManager _prototypeLoadManager = default!;
     [Dependency] private readonly NetworkResourceManager _networkResourceManager = default!;
 
     public void Initialize()
     {
         _netManager.Connected += NetManagerOnConnected;
+        _networkResourceManager.AckReceived += OnAckReceived;
+    }
+
+    private void OnAckReceived(INetChannel channel, int ack)
+    {
+        if (ack != NetworkResourceManager.AckInitial)
+            return;
+
+        ResourcesReady(channel);
     }
 
     private void NetManagerOnConnected(object? sender, NetChannelArgs e)
     {
         // This just shells out to the other managers, ensuring they are ordered properly.
         // Resources must be done before prototypes.
-        // Note: both net messages sent here are on the same group and are therefore ordered.
-        _networkResourceManager.SendToNewUser(e.Channel);
-        _prototypeLoadManager.SendToNewUser(e.Channel);
+        var sentAny = _networkResourceManager.SendToNewUser(e.Channel);
+        if (!sentAny)
+            ResourcesReady(e.Channel);
+    }
+
+    private void ResourcesReady(INetChannel channel)
+    {
+        _prototypeLoadManager.SendToNewUser(channel);
+        _playerManager.MarkPlayerResourcesSent(channel);
     }
 }

Robust.Server/ViewVariables/IViewVariablesSession.cs

@@ -12,5 +12,6 @@ namespace Robust.Server.ViewVariables
         object Object { get; }
         uint SessionId { get; }
         Type ObjectType { get; }
+        Action<object>? ObjectChangeDelegate { get; }
     }
 }

Robust.Server/ViewVariables/ServerViewVariablesManager.cs

@@ -3,7 +3,6 @@ using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 using Robust.Server.Console;
 using Robust.Server.Player;
-using Robust.Shared.Audio;
 using Robust.Shared.Enums;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
@@ -138,6 +137,7 @@ namespace Robust.Server.ViewVariables
             }
 
             object theObject;
+            Action<object>? objectChangeDelegate = null;
 
             switch (message.Selector)
             {
@@ -200,13 +200,14 @@ namespace Robust.Server.ViewVariables
                         return;
                     }
 
-                    if (value == null || value.GetType().IsValueType)
+                    if (value == null)
                     {
                         Deny(ViewVariablesResponseCode.NoObject);
                         return;
                     }
 
                     theObject = value;
+                    objectChangeDelegate = obj => relSession.Modify(sessionRelativeSelector.PropertyIndex, obj);
                     break;
                 }
                 case ViewVariablesIoCSelector ioCSelector:
@@ -250,7 +251,7 @@ namespace Robust.Server.ViewVariables
             }
 
             var sessionId = _nextSessionId++;
-            var session = new ViewVariablesSession(message.MsgChannel.UserId, theObject, sessionId, this,
+            var session = new ViewVariablesSession(message.MsgChannel.UserId, theObject, objectChangeDelegate, sessionId, this,
                 _robustSerializer, _entityManager, Sawmill);
 
             _sessions.Add(sessionId, session);

Robust.Server/ViewVariables/Traits/ViewVariablesTraitMembers.cs

@@ -2,7 +2,6 @@ using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Reflection;
-using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
 using Robust.Shared.Log;
 using Robust.Shared.Prototypes;
@@ -198,6 +197,8 @@ namespace Robust.Server.ViewVariables.Traits
                     try
                     {
                         field.SetValue(Session.Object, value);
+                        Session.ObjectChangeDelegate?.Invoke(Session.Object);
+
                         return true;
                     }
                     catch (Exception e)

Robust.Server/ViewVariables/ViewVariablesSession.cs

@@ -22,6 +22,7 @@ namespace Robust.Server.ViewVariables
         public object Object { get; }
         public uint SessionId { get; }
         public Type ObjectType { get; }
+        public Action<object>? ObjectChangeDelegate { get; }
 
         /// <param name="playerUser">The session ID of the player who opened this session.</param>
         /// <param name="o">The object we represent.</param>
@@ -29,13 +30,14 @@ namespace Robust.Server.ViewVariables
         ///     The session ID for this session. This is what the server and client use to talk about this session.
         /// </param>
         /// <param name="host">The view variables host owning this session.</param>
-        public ViewVariablesSession(NetUserId playerUser, object o, uint sessionId, IServerViewVariablesInternal host,
+        public ViewVariablesSession(NetUserId playerUser, object o, Action<object>? objectChangeDelegate, uint sessionId, IServerViewVariablesInternal host,
             IRobustSerializer robustSerializer, IEntityManager entMan, ISawmill logger)
         {
             PlayerUser = playerUser;
             Object = o;
             SessionId = sessionId;
             ObjectType = o.GetType();
+            ObjectChangeDelegate = objectChangeDelegate;
             Host = host;
             RobustSerializer = robustSerializer;
             EntityManager = entMan;

Robust.Server/run_server.bat

@@ -1,2 +1,5 @@
+@echo off
+
+cd /d "%~dp0"
 Robust.Server.exe
 pause

Robust.Shared.IntegrationTests/GameObjects/EntityState_Tests.cs

@@ -2,9 +2,14 @@ using System;
 using System.IO;
 using Moq;
 using NUnit.Framework;
+using Robust.Server;
 using Robust.Server.Configuration;
+using Robust.Server.Network.Transfer;
+using Robust.Server.Player;
 using Robust.Server.Reflection;
 using Robust.Server.Serialization;
+using Robust.Server.ServerStatus;
+using Robust.Shared.Asynchronous;
 using Robust.Shared.Configuration;
 using Robust.Shared.ContentPack;
 using Robust.Shared.GameObjects;
@@ -13,6 +18,7 @@ using Robust.Shared.Log;
 using Robust.Shared.Map;
 using Robust.Shared.Map.Components;
 using Robust.Shared.Network;
+using Robust.Shared.Network.Transfer;
 using Robust.Shared.Profiling;
 using Robust.Shared.Reflection;
 using Robust.Shared.Replays;
@@ -43,6 +49,7 @@ namespace Robust.UnitTesting.Shared.GameObjects
             container.Register<IAuthManager, AuthManager>();
             container.Register<IGameTiming, GameTiming>();
             container.Register<ProfManager, ProfManager>();
+            container.RegisterInstance<ITransferManager>(Mock.Of<ITransferManager>());
             container.Register<HttpClientHolder>();
             container.RegisterInstance<IReplayRecordingManager>(new Mock<IReplayRecordingManager>().Object);
             container.BuildGraph();

Robust.Shared.IntegrationTests/GameObjects/EntitySystemManagerOrderTest.cs

@@ -1,6 +1,3 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using Moq;
 using NUnit.Framework;
 using Robust.Server.Configuration;
@@ -88,7 +85,6 @@ namespace Robust.UnitTesting.Shared.GameObjects
             deps.Register<IDynamicTypeFactoryInternal, DynamicTypeFactory>();
             deps.RegisterInstance<IModLoader>(new Mock<IModLoader>().Object);
             deps.Register<IEntitySystemManager, EntitySystemManager>();
-            deps.RegisterInstance<IEntityManager>(new Mock<IEntityManager>().Object);
             // WHEN WILL THE SUFFERING END
             deps.RegisterInstance<IReplayRecordingManager>(new Mock<IReplayRecordingManager>().Object);
 
@@ -104,6 +100,15 @@ namespace Robust.UnitTesting.Shared.GameObjects
 
             deps.RegisterInstance<IReflectionManager>(reflectionMock.Object);
 
+            // Never
+            var componentFactoryMock = new Mock<IComponentFactory>();
+            componentFactoryMock.Setup(p => p.AllRegisteredTypes).Returns(Enumerable.Empty<Type>());
+            deps.RegisterInstance<IComponentFactory>(componentFactoryMock.Object);
+
+            var entityManagerMock = new Mock<IEntityManager>();
+            entityManagerMock.Setup(p => p.ComponentFactory).Returns(componentFactoryMock.Object);
+            deps.RegisterInstance<IEntityManager>(entityManagerMock.Object);
+
             deps.BuildGraph();
 
             IoCManager.InitThread(deps, true);

Robust.Shared.IntegrationTests/GameObjects/EntitySystemManager_Tests.cs

@@ -1,11 +1,10 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using NUnit.Framework;
 using Robust.Shared.Analyzers;
+using Robust.Shared.Configuration;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
 using Robust.Shared.IoC.Exceptions;
+using Robust.Shared.Physics.Components;
 
 namespace Robust.UnitTesting.Shared.GameObjects
 {
@@ -39,6 +38,14 @@ namespace Robust.UnitTesting.Shared.GameObjects
             [Dependency] public readonly ESystemDepA ESystemDepA = default!;
         }
 
+        internal sealed class ESystemDepAll : EntitySystem
+        {
+            [Dependency] public readonly ESystemDepA ESystemDepA = default!;
+            [Dependency] public readonly IConfigurationManager Config = default!;
+            [Dependency] public readonly EntityQuery<TransformComponent> TransformQuery = default!;
+            [Dependency] public readonly EntityQuery<PhysicsComponent> PhysicsQuery = default!;
+        }
+
         /*
          ESystemBase (Abstract)
            - ESystemA
@@ -58,6 +65,7 @@ namespace Robust.UnitTesting.Shared.GameObjects
             syssy.LoadExtraSystemType<ESystemC>();
             syssy.LoadExtraSystemType<ESystemDepA>();
             syssy.LoadExtraSystemType<ESystemDepB>();
+            syssy.LoadExtraSystemType<ESystemDepAll>();
             syssy.Initialize(false);
         }
 
@@ -103,5 +111,16 @@ namespace Robust.UnitTesting.Shared.GameObjects
             Assert.That(sysB.ESystemDepA, Is.EqualTo(sysA));
         }
 
+        [Test]
+        public void DependencyInjectionTest()
+        {
+            var esm = IoCManager.Resolve<IEntitySystemManager>();
+            var sys = esm.GetEntitySystem<ESystemDepAll>();
+
+            Assert.That(sys.ESystemDepA, Is.Not.Null);
+            Assert.That(sys.Config, Is.Not.Null);
+            Assert.That(sys.TransformQuery, Is.Not.Default);
+            Assert.That(sys.PhysicsQuery, Is.Not.Default);
+        }
     }
 }

Robust.Shared.IntegrationTests/Serialization/NetSerializerDefaultFloatTest.cs

@@ -0,0 +1,203 @@
+using JetBrains.Annotations;
+using NUnit.Framework;
+using Robust.Shared.IoC;
+using Robust.Shared.Maths;
+using Robust.Shared.Serialization;
+using Robust.UnitTesting.Shared;
+
+namespace Robust.Shared.IntegrationTests.Serialization;
+
+[Serializable, NetSerializable]
+[UsedImplicitly(Reason = "Needed so RobustSerializer is guaranteed to pick up on the unsafe types.")]
+internal sealed class MakeTheseSerializable
+{
+    public UnsafeFloat Single;
+    public UnsafeDouble Double;
+    public UnsafeHalf Half;
+    public Half SafeHalf;
+}
+
+/// <summary>
+/// Tests the serialization behavior of float types when <see cref="IRobustSerializer"/> is *not* set to do anything special.
+/// Tests both primitives and Robust's "Unsafe" variants.
+/// </summary>
+[TestFixture, TestOf(typeof(RobustSerializer)), TestOf(typeof(NetUnsafeFloatSerializer))]
+internal sealed class NetSerializerDefaultFloatTest : OurRobustUnitTest
+{
+    private IRobustSerializer _serializer = null!;
+
+    [OneTimeSetUp]
+    public void Setup()
+    {
+        _serializer = IoCManager.Resolve<IRobustSerializer>();
+        _serializer.Initialize();
+    }
+
+    internal static readonly TestCaseData[] PassThroughFloatTests =
+    [
+        new TestCaseData(0.0).Returns(0.0),
+        new TestCaseData(1.0).Returns(1.0),
+        new TestCaseData(double.NaN).Returns(double.NaN),
+        new TestCaseData(double.PositiveInfinity).Returns(double.PositiveInfinity),
+    ];
+
+    [TestCaseSource(nameof(PassThroughFloatTests))]
+    public double TestSingle(double input)
+    {
+        var ms = new MemoryStream();
+        _serializer.Serialize(ms, (float)input);
+
+        ms.Position = 0;
+
+        return _serializer.Deserialize<float>(ms);
+    }
+
+    [TestCaseSource(nameof(PassThroughFloatTests))]
+    public double TestUnsafeSingle(double input)
+    {
+        var ms = new MemoryStream();
+        _serializer.Serialize(ms, (UnsafeFloat)input);
+
+        ms.Position = 0;
+
+        return _serializer.Deserialize<UnsafeFloat>(ms);
+    }
+
+    [TestCaseSource(nameof(PassThroughFloatTests))]
+    public double TestDouble(double input)
+    {
+        var ms = new MemoryStream();
+        _serializer.Serialize(ms, input);
+
+        ms.Position = 0;
+
+        return _serializer.Deserialize<double>(ms);
+    }
+
+    [TestCaseSource(nameof(PassThroughFloatTests))]
+    public double TestUnsafeDouble(double input)
+    {
+        var ms = new MemoryStream();
+        _serializer.Serialize(ms, (UnsafeDouble)input);
+
+        ms.Position = 0;
+
+        return _serializer.Deserialize<UnsafeDouble>(ms);
+    }
+
+    [TestCaseSource(nameof(PassThroughFloatTests))]
+    public double TestHalf(double input)
+    {
+        var ms = new MemoryStream();
+        _serializer.Serialize(ms, (Half)input);
+
+        ms.Position = 0;
+
+        return (double)_serializer.Deserialize<Half>(ms);
+    }
+
+    [TestCaseSource(nameof(PassThroughFloatTests))]
+    public double TestUnsafeHalf(double input)
+    {
+        var ms = new MemoryStream();
+        _serializer.Serialize(ms, (UnsafeHalf)(Half)input);
+
+        ms.Position = 0;
+
+        return (double)(Half)_serializer.Deserialize<UnsafeHalf>(ms);
+    }
+}
+
+/// <summary>
+/// Tests the serialization behavior of float types when <see cref="IRobustSerializer"/> is set to remove NaNs on read.
+/// Tests both primitives and Robust's "Unsafe" variants.
+/// </summary>
+[TestFixture]
+[TestOf(typeof(RobustSerializer)), TestOf(typeof(NetUnsafeFloatSerializer)), TestOf(typeof(NetSafeFloatSerializer))]
+internal sealed class NetSerializerSafeFloatTest : OurRobustUnitTest
+{
+    private IRobustSerializer _serializer = default!;
+
+    [OneTimeSetUp]
+    public void Setup()
+    {
+        _serializer = IoCManager.Resolve<IRobustSerializer>();
+        _serializer.FloatFlags = SerializerFloatFlags.RemoveReadNan;
+        _serializer.Initialize();
+    }
+
+    internal static readonly TestCaseData[] SafeFloatTests =
+    [
+        new TestCaseData(0.0).Returns(0.0),
+        new TestCaseData(1.0).Returns(1.0),
+        new TestCaseData(double.NaN).Returns(0.0),
+        new TestCaseData(double.PositiveInfinity).Returns(double.PositiveInfinity),
+    ];
+
+    [TestCaseSource(nameof(SafeFloatTests))]
+    public double TestSingle(double input)
+    {
+        var ms = new MemoryStream();
+        _serializer.Serialize(ms, (float)input);
+
+        ms.Position = 0;
+
+        return _serializer.Deserialize<float>(ms);
+    }
+
+    [TestCaseSource(typeof(NetSerializerDefaultFloatTest), nameof(NetSerializerDefaultFloatTest.PassThroughFloatTests))]
+    public double TestUnsafeSingle(double input)
+    {
+        var ms = new MemoryStream();
+        _serializer.Serialize(ms, (UnsafeFloat)input);
+
+        ms.Position = 0;
+
+        return _serializer.Deserialize<UnsafeFloat>(ms);
+    }
+
+    [TestCaseSource(nameof(SafeFloatTests))]
+    public double TestDouble(double input)
+    {
+        var ms = new MemoryStream();
+        _serializer.Serialize(ms, input);
+
+        ms.Position = 0;
+
+        return _serializer.Deserialize<double>(ms);
+    }
+
+    [TestCaseSource(typeof(NetSerializerDefaultFloatTest), nameof(NetSerializerDefaultFloatTest.PassThroughFloatTests))]
+    public double TestUnsafeDouble(double input)
+    {
+        var ms = new MemoryStream();
+        _serializer.Serialize(ms, (UnsafeDouble)input);
+
+        ms.Position = 0;
+
+        return _serializer.Deserialize<UnsafeDouble>(ms);
+    }
+
+
+    [TestCaseSource(nameof(SafeFloatTests))]
+    public double TestHalf(double input)
+    {
+        var ms = new MemoryStream();
+        _serializer.Serialize(ms, (Half)input);
+
+        ms.Position = 0;
+
+        return (double)_serializer.Deserialize<Half>(ms);
+    }
+
+    [TestCaseSource(typeof(NetSerializerDefaultFloatTest), nameof(NetSerializerDefaultFloatTest.PassThroughFloatTests))]
+    public double TestUnsafeHalf(double input)
+    {
+        var ms = new MemoryStream();
+        _serializer.Serialize(ms, (UnsafeHalf)(Half)input);
+
+        ms.Position = 0;
+
+        return (double)(Half)_serializer.Deserialize<UnsafeHalf>(ms);
+    }
+}

Robust.Shared.Maths/UnsafeFloat.cs

@@ -0,0 +1,53 @@
+using System;
+
+namespace Robust.Shared.Maths;
+
+/// <summary>
+/// Marker type to indicate floating point values that should preserve NaNs across the network.
+/// </summary>
+/// <remarks>
+/// Robust's network serializer may be configured to flush NaN float values to 0,
+/// to avoid exploits from lacking input validation. Even if this feature is enabled,
+/// NaN values passed in this type are still untouched.
+/// </remarks>
+/// <param name="Value">The actual inner floating point value</param>
+/// <seealso cref="System.Half"/>
+public readonly record struct UnsafeHalf(Half Value)
+{
+    public static implicit operator Half(UnsafeHalf f) => f.Value;
+    public static implicit operator UnsafeHalf(Half f) => new(f);
+}
+
+/// <summary>
+/// Marker type to indicate floating point values that should preserve NaNs across the network.
+/// </summary>
+/// <remarks>
+/// Robust's network serializer may be configured to flush NaN float values to 0,
+/// to avoid exploits from lacking input validation. Even if this feature is enabled,
+/// NaN values passed in this type are still untouched.
+/// </remarks>
+/// <param name="Value">The actual inner floating point value</param>
+/// <seealso cref="System.Single"/>
+public readonly record struct UnsafeFloat(float Value)
+{
+    public static implicit operator float(UnsafeFloat f) => f.Value;
+    public static implicit operator UnsafeFloat(float f) => new(f);
+}
+
+/// <summary>
+/// Marker type to indicate floating point values that should preserve NaNs across the network.
+/// </summary>
+/// <remarks>
+/// Robust's network serializer may be configured to flush NaN float values to 0,
+/// to avoid exploits from lacking input validation. Even if this feature is enabled,
+/// NaN values passed in this type are still untouched.
+/// </remarks>
+/// <param name="Value">The actual inner floating point value</param>
+/// <seealso cref="System.Double"/>
+public readonly record struct UnsafeDouble(double Value)
+{
+    public static implicit operator double(UnsafeDouble f) => f.Value;
+    public static implicit operator UnsafeDouble(double f) => new(f);
+    public static implicit operator UnsafeDouble(float f) => new(f);
+    public static implicit operator UnsafeDouble(UnsafeFloat f) => new(f);
+}

Robust.Shared/Audio/Systems/SharedAudioSystem.cs

@@ -75,6 +75,7 @@ public abstract partial class SharedAudioSystem : EntitySystem
             return;
 
         var audioLength = GetAudioLength(entity.Comp.FileName);
+        position = CalculateAudioPosition(entity!, (float)audioLength.TotalSeconds, position);
 
         if (audioLength.TotalSeconds < position)
         {
@@ -86,12 +87,6 @@ public abstract partial class SharedAudioSystem : EntitySystem
             return;
         }
 
-        if (position < 0f)
-        {
-            Log.Error($"Tried to set playback position for {ToPrettyString(entity.Owner)} / {entity.Comp.FileName} outside of bounds");
-            return;
-        }
-
         // If we're paused then the current position is <pause time - start time>, else it's <cur time - start time>
         var currentPos = (entity.Comp.PauseTime ?? Timing.CurTime) - entity.Comp.AudioStart;
         var timeOffset = TimeSpan.FromSeconds(position - currentPos.TotalSeconds);
@@ -315,6 +310,36 @@ public abstract partial class SharedAudioSystem : EntitySystem
         return GetAudioPath(resolved);
     }
 
+    /// <summary>
+    /// Calculates the current playback position of an audio entity
+    /// and clamps it to the range from 0 to (length - 0.01f).
+    /// </summary>
+    /// <param name="ent">The audio entity.</param>
+    /// <param name="length">
+    /// The total length of the audio file.
+    /// If null, the method retrieves the length using <see cref="GetAudioLength"/>.
+    /// </param>
+    /// <param name="position">
+    /// A precomputed playback position.
+    /// If provided, it will be added to the calculation.
+    /// </param>
+    /// <returns>The playback position as a float.</returns>
+    protected float CalculateAudioPosition(Entity<AudioComponent> ent, float? length = null, float? position = null)
+    {
+        position ??= (float) ((ent.Comp.PauseTime ?? Timing.CurTime) - ent.Comp.AudioStart).TotalSeconds;
+        length ??= (float) GetAudioLength(ent.Comp.FileName).TotalSeconds;
+
+        // Looped audio has no conceptual start or end.
+        if (ent.Comp.Params.Loop)
+            position %= length;
+
+        // TODO clamp the offset inside of AudioSource.SetPlaybackPosition() itself.
+        var maxOffset = Math.Max((float) length - 0.01f, 0f);
+        position = Math.Clamp(position.Value, 0f, maxOffset);
+
+        return position.Value;
+    }
+
     #region AudioParams
 
     [return: NotNullIfNotNull(nameof(specifier))]
@@ -455,7 +480,7 @@ public abstract partial class SharedAudioSystem : EntitySystem
         if (uid == null || !Resolve(uid.Value, ref component, false))
             return null;
 
-        if (_netManager.IsClient && !IsClientSide(uid.Value))
+        if (!Timing.IsFirstTimePredicted || (_netManager.IsClient && !IsClientSide(uid.Value)))
             return null;
 
         QueueDel(uid);

Robust.Shared/CVars.cs

@@ -406,6 +406,46 @@ namespace Robust.Shared
         public static readonly CVarDef<bool> NetHWId =
             CVarDef.Create("net.hwid", true, CVar.SERVERONLY);
 
+        /**
+         * TRANSFER
+         */
+
+        /// <summary>
+        /// If true, enable the WebSocket-based high bandwidth transfer channel.
+        /// </summary>
+        /// <remarks>
+        /// <para>
+        /// If set, <see cref="TransferHttpEndpoint"/> must be set to the API address of the server,
+        /// and you must ensure your reverse proxy (if you have one) is configured to allow WebSocket connections.
+        /// </para>
+        /// <para>
+        /// The transfer channel has no additional encryption layer. Unless your API is exposed behind HTTPS,
+        /// traffic over the channel will not be encrypted, and you are discouraged from enabling it.
+        /// </para>
+        /// </remarks>
+        public static readonly CVarDef<bool> TransferHttp =
+            CVarDef.Create("transfer.http", false, CVar.SERVERONLY);
+
+        /// <summary>
+        /// The base HTTP URL of the game server, used for the high-bandwidth transfer channel.
+        /// </summary>
+        public static readonly CVarDef<string> TransferHttpEndpoint =
+            CVarDef.Create("transfer.http_endpoint", "http://localhost:1212/", CVar.SERVERONLY);
+
+        /// <summary>
+        /// Amount of concurrent client->server transfer streams allowed.
+        /// </summary>
+        /// <remarks>
+        /// Clients will be disconnected if they exceed this limit.
+        /// </remarks>
+        public static readonly CVarDef<int> TransferStreamLimit =
+            CVarDef.Create("transfer.stream_limit", 10, CVar.SERVERONLY);
+
+        /// <summary>
+        /// Artificially delay transfer operations to simulate slow network. Debug option.
+        /// </summary>
+        internal static readonly CVarDef<bool> TransferArtificialDelay =
+            CVarDef.Create("transfer.artificial_delay", false);
 
         /**
          * SUS

Robust.Shared/ComponentTrees/ComponentTreeSystem.cs

@@ -205,60 +205,67 @@ public abstract class ComponentTreeSystem<TTreeComp, TComp> : EntitySystem
     /// </summary>
     public void UpdateTreePositions()
     {
-        if (!CheckEnabled())
-            return;
-
-        if (_updateQueue.Count == 0)
-            return;
-
-        var trees = GetEntityQuery<TTreeComp>();
-
-        while (_updateQueue.TryDequeue(out var entry))
+        try
         {
-            var (comp, xform) = entry;
+            if (!CheckEnabled())
+                return;
 
-            // Was this entity queued multiple times?
-            DebugTools.Assert(comp.TreeUpdateQueued, "Entity was queued multiple times?");
+            if (_updateQueue.Count == 0)
+                return;
 
-            comp.TreeUpdateQueued = false;
-            if (!comp.Running)
-                continue;
+            var trees = GetEntityQuery<TTreeComp>();
 
-            if (!comp.AddToTree || comp.Deleted || xform.MapUid == null)
+            while (_updateQueue.TryDequeue(out var entry))
             {
+                var (comp, xform) = entry;
+
+                // Was this entity queued multiple times?
+                DebugTools.Assert(comp.TreeUpdateQueued, "Entity was queued multiple times?");
+
+                comp.TreeUpdateQueued = false;
+                if (!comp.Running)
+                    continue;
+
+                if (!comp.AddToTree || comp.Deleted || xform.MapUid == null)
+                {
+                    RemoveFromTree(comp);
+                    continue;
+                }
+
+                var newTree = xform.GridUid ?? xform.MapUid;
+                if (!trees.TryGetComponent(newTree, out var newTreeComp) && comp.TreeUid == null)
+                    continue;
+
+                Vector2 pos;
+                Angle rot;
+                if (comp.TreeUid == newTree)
+                {
+                    (pos, rot) = XformSystem.GetRelativePositionRotation(
+                        entry.Transform,
+                        newTree!.Value);
+
+                    newTreeComp!.Tree.Update(entry, ExtractAabb(entry, pos, rot));
+                    continue;
+                }
+
                 RemoveFromTree(comp);
-                continue;
-            }
 
-            var newTree = xform.GridUid ?? xform.MapUid;
-            if (!trees.TryGetComponent(newTree, out var newTreeComp) && comp.TreeUid == null)
-                continue;
+                if (newTreeComp == null)
+                    return;
+
+                comp.TreeUid = newTree;
+                comp.Tree = newTreeComp.Tree;
 
-            Vector2 pos;
-            Angle rot;
-            if (comp.TreeUid == newTree)
-            {
                 (pos, rot) = XformSystem.GetRelativePositionRotation(
                     entry.Transform,
                     newTree!.Value);
 
-                newTreeComp!.Tree.Update(entry, ExtractAabb(entry, pos, rot));
-                continue;
+                newTreeComp.Tree.Add(entry, ExtractAabb(entry, pos, rot));
             }
-
-            RemoveFromTree(comp);
-
-            if (newTreeComp == null)
-                return;
-
-            comp.TreeUid = newTree;
-            comp.Tree = newTreeComp.Tree;
-
-            (pos, rot) = XformSystem.GetRelativePositionRotation(
-                entry.Transform,
-                newTree!.Value);
-
-            newTreeComp.Tree.Add(entry, ExtractAabb(entry, pos, rot));
+        }
+        finally
+        {
+            _updateQueue.Clear();
         }
     }
 

Robust.Shared/Console/Commands/DumpStringTableCommand.cs

@@ -0,0 +1,23 @@
+using System.Linq;
+using Robust.Shared.IoC;
+using Robust.Shared.Network;
+
+namespace Robust.Shared.Console.Commands;
+
+internal sealed class DumpStringTableCommand : IConsoleCommand
+{
+    [Dependency] private readonly INetManager _netManager = default!;
+
+    public string Command  => "net_dumpstringtable";
+    public string Description  => "";
+    public string Help => "";
+
+    public void Execute(IConsoleShell shell, string argStr, string[] args)
+    {
+        var netMgr = (NetManager)_netManager;
+        foreach (var (k, v) in netMgr.StringTable.Strings.OrderBy(x => x.Key))
+        {
+            shell.WriteLine($"{k}: {v}");
+        }
+    }
+}

Robust.Shared/Containers/SharedContainerSystem.Remove.cs

@@ -101,7 +101,7 @@ public abstract partial class SharedContainerSystem
         RaiseLocalEvent(container.Owner, new EntRemovedFromContainerMessage(toRemove, container), true);
         RaiseLocalEvent(toRemove, new EntGotRemovedFromContainerMessage(toRemove, container), false);
 
-        DebugTools.Assert(destination == null || xform.Coordinates.Equals(destination.Value), "failed to set destination");
+        DebugTools.Assert(destination == null || xform.Coordinates.Equals(destination.Value), $"Failed to set coordinates of {ToPrettyString(toRemove, meta)} to be inside {ToPrettyString(container.Owner)} container '{container.ID}'");
 
         Dirty(container.Owner, container.Manager);
         return true;

Robust.Shared/ContentPack/AssemblyTypeChecker.ReportBadReferences.cs

@@ -14,12 +14,9 @@ namespace Robust.Shared.ContentPack;
 internal sealed partial class AssemblyTypeChecker
 {
     // This part of the code tries to find the originator of bad sandbox references.
-
-    private void ReportBadReferences(PEReader peReader, MetadataReader reader, IEnumerable<EntityHandle> reference)
+    private IEnumerable<(EntityHandle Referenced, MethodDefinitionHandle SourceMethod, int InstructionOffset)> FindReference(PEReader peReader, MetadataReader reader, params IEnumerable<EntityHandle> handles)
     {
-        _sawmill.Info("Started search for originator of bad references...");
-
-        var refs = reference.ToHashSet();
+        var refs = handles.ToHashSet();
         ExpandReferences(reader, refs);
 
         foreach (var methodDefHandle in reader.MethodDefinitions)
@@ -28,8 +25,6 @@ internal sealed partial class AssemblyTypeChecker
             if (methodDef.RelativeVirtualAddress == 0)
                 continue;
 
-            var methodName = reader.GetString(methodDef.Name);
-
             var body = peReader.GetMethodBody(methodDef.RelativeVirtualAddress);
             var bytes = body.GetILBytes()!;
 
@@ -41,9 +36,7 @@ internal sealed partial class AssemblyTypeChecker
                 {
                     if (refs.Overlaps(ExpandHandle(reader, handle)))
                     {
-                        var type = GetTypeFromDefinition(reader, methodDef.GetDeclaringType());
-                        _sawmill.Error(
-                            $"Found reference to {DisplayHandle(reader, handle)} in method {type}.{methodName} at IL 0x{prefPosition:X4}");
+                        yield return (handle, methodDefHandle, prefPosition);
                     }
                 }
 
@@ -52,6 +45,19 @@ internal sealed partial class AssemblyTypeChecker
         }
     }
 
+    private void ReportBadReferences(PEReader peReader, MetadataReader reader, IEnumerable<EntityHandle> reference)
+    {
+        foreach (var (referenced, method, ilOffset) in FindReference(peReader, reader, reference))
+        {
+            var methodDef = reader.GetMethodDefinition(method);
+            var methodName = reader.GetString(methodDef.Name);
+
+            var type = GetTypeFromDefinition(reader, methodDef.GetDeclaringType());
+            _sawmill.Error(
+                $"Found reference to {DisplayHandle(reader, referenced)} in method {type}.{methodName} at IL 0x{ilOffset:X4}");
+        }
+    }
+
     private static string DisplayHandle(MetadataReader reader, EntityHandle handle)
     {
         switch (handle.Kind)

Robust.Shared/ContentPack/AssemblyTypeChecker.cs

@@ -227,6 +227,8 @@ namespace Robust.Shared.ContentPack
 #if TOOLS
             if (!badRefs.IsEmpty)
             {
+                _sawmill.Info("Started search for originator of bad references...");
+
                 ReportBadReferences(peReader, reader, badRefs);
             }
 #endif
@@ -298,6 +300,9 @@ namespace Robust.Shared.ContentPack
 
                 verifyErrors = true;
                 _sawmill.Error(msg);
+
+                if (!res.Method.IsNil)
+                    PrintCompilerGeneratedMethodUsage(peReader, reader, res.Method);
             }
 
             _sawmill.Debug($"{name}: Verified IL in {sw.Elapsed.TotalMilliseconds}ms");
@@ -310,6 +315,24 @@ namespace Robust.Shared.ContentPack
             return true;
         }
 
+        private void PrintCompilerGeneratedMethodUsage(
+            PEReader peReader,
+            MetadataReader reader,
+            MethodDefinitionHandle method)
+        {
+#if TOOLS
+            var methodDef = reader.GetMethodDefinition(method);
+            var type = GetTypeFromDefinition(reader, methodDef.GetDeclaringType());
+
+            if (!type.Name.Contains('<'))
+                return;
+
+            _sawmill.Error("Hint: method is compiler-generated. Check for params collections and/or collection expressions:");
+
+            ReportBadReferences(peReader, reader, [method]);
+#endif
+        }
+
         private static string FormatMethodName(MetadataReader reader, MethodDefinition method)
         {
             var methodSig = method.DecodeSignature(new TypeProvider(), 0);

Robust.Shared/ContentPack/PathHelpers.cs

@@ -1,7 +1,6 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
-using System.Runtime.InteropServices;
 using Robust.Shared.Utility;
 
 namespace Robust.Shared.ContentPack
@@ -16,8 +15,7 @@ namespace Robust.Shared.ContentPack
         /// </summary>
         internal static string GetExecutableDirectory()
         {
-            // TODO: remove this shitty hack, either through making it less hardcoded into shared,
-            //   or by making our file structure less spaghetti somehow.
+            // Fallback in case the above doesn't work ig?
             var assembly = typeof(PathHelpers).Assembly;
             var location = assembly.Location;
             if (location == string.Empty)

Robust.Shared/ContentPack/Sandbox.yml

@@ -444,6 +444,7 @@ Types:
     LinkedList`1: { All: True }
     LinkedListNode`1: { All: True }
     List`1: { All: True }
+    OrderedDictionary`2: { All: True }
     Queue`1: { All: True }
     ReferenceEqualityComparer: { All: True }
     SortedDictionary`2: { All: True }
@@ -1462,6 +1463,7 @@ Types:
       - "void .ctor(char[], int, int)"
       - "void .ctor(System.ReadOnlySpan`1<char>)"
       - "void CopyTo(int, char[], int, int)"
+    StringComparer: { All: True }
     StringComparison: { } # Enum
     StringSplitOptions: { } # Enum
     TimeOnly: { All: True }

Robust.Shared/EntitySerialization/Systems/MapLoaderSystem.Load.cs

@@ -19,8 +19,8 @@ namespace Robust.Shared.EntitySerialization.Systems;
 public sealed partial class MapLoaderSystem
 {
     /// <summary>
-    /// Tries to load entities from a yaml file. Whenever possible, you should try to use <see cref="TryLoadMap"/>,
-    /// <see cref="TryLoadGrid"/>, or <see cref="TryLoadEntity"/> instead.
+    ///     Tries to load entities from a YAML file. Whenever possible, you should try to use <see cref="TryLoadMap"/>,
+    ///     <see cref="TryLoadGrid"/>, or <see cref="TryLoadEntity"/> instead.
     /// </summary>
     public bool TryLoadGeneric(
         ResPath file,
@@ -30,6 +30,7 @@ public sealed partial class MapLoaderSystem
     {
         grids = null;
         maps = null;
+
         if (!TryLoadGeneric(file, out var data, options))
             return false;
 
@@ -39,33 +40,29 @@ public sealed partial class MapLoaderSystem
     }
 
     /// <summary>
-    /// Tries to load entities from a YAML file, taking in a raw byte stream.
+    ///     Tries to load entities from a YAML text stream. Whenever possible, you should try to use <see cref="TryLoadMap"/>,
+    ///     <see cref="TryLoadGrid"/>, or <see cref="TryLoadEntity"/> instead.
     /// </summary>
-    /// <param name="file">The file contents to load from.</param>
-    /// <param name="fileName">
-    /// The name of the file being loaded. This is used purely for logging/informational purposes.
-    /// </param>
-    /// <param name="result">The result of the load operation.</param>
-    /// <param name="options">Options for the load operation.</param>
-    /// <returns>True if the load succeeded, false otherwise.</returns>
-    /// <seealso cref="M:Robust.Shared.EntitySerialization.Systems.MapLoaderSystem.TryLoadGeneric(Robust.Shared.Utility.ResPath,Robust.Shared.EntitySerialization.LoadResult@,System.Nullable{Robust.Shared.EntitySerialization.MapLoadOptions})"/>
     public bool TryLoadGeneric(
-        Stream file,
-        string fileName,
-        [NotNullWhen(true)] out LoadResult? result,
+        TextReader reader,
+        string source,
+        [NotNullWhen(true)] out HashSet<Entity<MapComponent>>? maps,
+        [NotNullWhen(true)] out HashSet<Entity<MapGridComponent>>? grids,
         MapLoadOptions? options = null)
     {
-        result = null;
-
-        if (!TryReadFile(new StreamReader(file), out var data))
+        grids = null;
+        maps = null;
+        if (!TryLoadGeneric(reader, source, out var data, options))
             return false;
 
-        return TryLoadGeneric(data, fileName, out result, options);
+        maps = data.Maps;
+        grids = data.Grids;
+        return true;
     }
 
     /// <summary>
-    /// Tries to load entities from a yaml file. Whenever possible, you should try to use <see cref="TryLoadMap"/>,
-    /// <see cref="TryLoadGrid"/>, or <see cref="TryLoadEntity"/> instead.
+    ///     Tries to load entities from a YAML file. Whenever possible, you should try to use <see cref="TryLoadMap"/>,
+    ///     <see cref="TryLoadGrid"/>, or <see cref="TryLoadEntity"/> instead.
     /// </summary>
     /// <param name="file">The file to load.</param>
     /// <param name="result">Data class containing information about the loaded entities</param>
@@ -74,15 +71,51 @@ public sealed partial class MapLoaderSystem
     {
         result = null;
 
-        if (!TryReadFile(file, out var data))
+        if (!TryReadFile(file.ToRootedPath(), out var data))
             return false;
 
         return TryLoadGeneric(data, file.ToString(), out result, options);
     }
 
-    private bool TryLoadGeneric(
+    /// <summary>
+    ///     Tries to load entities from a YAML text stream. Whenever possible, you should try to use <see cref="TryLoadMap"/>,
+    ///     <see cref="TryLoadGrid"/>, or <see cref="TryLoadEntity"/> instead.
+    /// </summary>
+    /// <param name="reader">The text to load.</param>
+    /// <param name="source">The name of the source, if any. This should be your file path (for example)</param>
+    /// <param name="result">Data class containing information about the loaded entities</param>
+    /// <param name="options">Optional Options for configuring loading behaviour.</param>
+    public bool TryLoadGeneric(TextReader reader, string source, [NotNullWhen(true)] out LoadResult? result, MapLoadOptions? options = null)
+    {
+        result = null;
+
+        if (!TryReadFile(reader, out var data))
+            return false;
+
+        return TryLoadGeneric(data, source, out result, options);
+    }
+
+    /// <summary>
+    ///     Tries to load entities from a YAML text stream. Whenever possible, you should try to use <see cref="TryLoadMap"/>,
+    ///     <see cref="TryLoadGrid"/>, or <see cref="TryLoadEntity"/> instead.
+    /// </summary>
+    /// <param name="stream">The stream containing the text to load.</param>
+    /// <param name="source">The name of the source, if any. This should be your file path (for example)</param>
+    /// <param name="result">Data class containing information about the loaded entities</param>
+    /// <param name="options">Optional Options for configuring loading behaviour.</param>
+    public bool TryLoadGeneric(Stream stream, string source, [NotNullWhen(true)] out LoadResult? result, MapLoadOptions? options = null)
+    {
+        result = null;
+
+        if (!TryReadFile(new StreamReader(stream, leaveOpen: true), out var data))
+            return false;
+
+        return TryLoadGeneric(data, source, out result, options);
+    }
+
+    public bool TryLoadGeneric(
         MappingDataNode data,
-        string fileName,
+        string source,
         [NotNullWhen(true)] out LoadResult? result,
         MapLoadOptions? options = null)
     {
@@ -118,7 +151,7 @@ public sealed partial class MapLoaderSystem
 
         if (!deserializer.TryProcessData())
         {
-            Log.Debug($"Failed to process entity data in {fileName}");
+            Log.Debug($"Failed to process entity data in {source}");
             return false;
         }
 
@@ -128,7 +161,7 @@ public sealed partial class MapLoaderSystem
             && deserializer.Result.Category != FileCategory.Unknown)
         {
             // Did someone try to load a map file as a grid or vice versa?
-            Log.Error($"Map {fileName} does not contain the expected data. Expected {expected} but got {deserializer.Result.Category}");
+            Log.Error($"Map {source} does not contain the expected data. Expected {expected} but got {deserializer.Result.Category}");
             Delete(deserializer.Result);
             return false;
         }
@@ -139,7 +172,7 @@ public sealed partial class MapLoaderSystem
         }
         catch (Exception e)
         {
-            Log.Error($"Caught exception while creating entities for map {fileName}: {e}");
+            Log.Error($"Caught exception while creating entities for map {source}: {e}");
             Delete(deserializer.Result);
             throw;
         }
@@ -149,7 +182,7 @@ public sealed partial class MapLoaderSystem
         if (opts.ExpectedCategory is { } exp && exp != deserializer.Result.Category)
         {
             // Did someone try to load a map file as a grid or vice versa?
-            Log.Error($"Map {fileName} does not contain the expected data. Expected {exp} but got {deserializer.Result.Category}");
+            Log.Error($"Map {source} does not contain the expected data. Expected {exp} but got {deserializer.Result.Category}");
             Delete(deserializer.Result);
             return false;
         }
@@ -184,12 +217,33 @@ public sealed partial class MapLoaderSystem
     }
 
     /// <summary>
-    /// Tries to load a regular (non-map, non-grid) entity from a file.
-    /// The loaded entity will initially be in null-space.
-    /// If the file does not contain exactly one orphaned entity, this will return false and delete loaded entities.
+    ///     Tries to load a regular (non-map, non-grid) entity from a YAML file.
+    ///     The loaded entity will initially be in null-space.
+    ///     If the file does not contain exactly one orphaned entity, this will return false and delete loaded entities.
     /// </summary>
     public bool TryLoadEntity(
-        ResPath path,
+        ResPath file,
+        [NotNullWhen(true)] out Entity<TransformComponent>? entity,
+        DeserializationOptions? options = null)
+    {
+        entity = null;
+        if (!TryGetReader(file.ToRootedPath(), out var reader))
+            return false;
+
+        using (reader)
+        {
+            return TryLoadEntity(reader, file.ToString(), out entity, options);
+        }
+    }
+
+    /// <summary>
+    ///     Tries to load a regular (non-map, non-grid) entity from a YAML text stream.
+    ///     The loaded entity will initially be in null-space.
+    ///     If the file does not contain exactly one orphaned entity, this will return false and delete loaded entities.
+    /// </summary>
+    public bool TryLoadEntity(
+        TextReader reader,
+        string source,
         [NotNullWhen(true)] out Entity<TransformComponent>? entity,
         DeserializationOptions? options = null)
     {
@@ -200,7 +254,7 @@ public sealed partial class MapLoaderSystem
         };
 
         entity = null;
-        if (!TryLoadGeneric(path, out var result, opts))
+        if (!TryLoadGeneric(reader, source, out var result, opts))
             return false;
 
         if (result.Orphans.Count == 1)
@@ -215,12 +269,35 @@ public sealed partial class MapLoaderSystem
     }
 
     /// <summary>
-    /// Tries to load a grid entity from a file and parent it to the given map.
-    /// If the file does not contain exactly one grid, this will return false and delete loaded entities.
+    ///     Tries to load a grid entity from a YAML file and parent it to the given map.
+    ///     If the file does not contain exactly one grid, this will return false and delete loaded entities.
     /// </summary>
     public bool TryLoadGrid(
         MapId map,
-        ResPath path,
+        ResPath file,
+        [NotNullWhen(true)] out Entity<MapGridComponent>? grid,
+        DeserializationOptions? options = null,
+        Vector2 offset = default,
+        Angle rot = default)
+    {
+        grid = null;
+        if (!TryGetReader(file.ToRootedPath(), out var reader))
+            return false;
+
+        using (reader)
+        {
+            return TryLoadGrid(map, reader, file.ToString(), out grid, options, offset, rot);
+        }
+    }
+
+    /// <summary>
+    ///     Tries to load a grid entity from a YAML text stream and parent it to the given map.
+    ///     If the file does not contain exactly one grid, this will return false and delete loaded entities.
+    /// </summary>
+    public bool TryLoadGrid(
+        MapId map,
+        TextReader reader,
+        string source,
         [NotNullWhen(true)] out Entity<MapGridComponent>? grid,
         DeserializationOptions? options = null,
         Vector2 offset = default,
@@ -236,7 +313,7 @@ public sealed partial class MapLoaderSystem
         };
 
         grid = null;
-        if (!TryLoadGeneric(path, out var result, opts))
+        if (!TryLoadGeneric(reader, source, out var result, opts))
             return false;
 
         if (result.Grids.Count == 1)
@@ -250,11 +327,35 @@ public sealed partial class MapLoaderSystem
     }
 
     /// <summary>
-    /// Tries to load a grid entity from a file and parent it to a newly created map.
+    /// Tries to load a grid entity from a YAML file and parent it to a newly created map.
     /// If the file does not contain exactly one grid, this will return false and delete loaded entities.
     /// </summary>
     public bool TryLoadGrid(
-        ResPath path,
+        ResPath file,
+        [NotNullWhen(true)] out Entity<MapComponent>? map,
+        [NotNullWhen(true)] out Entity<MapGridComponent>? grid,
+        DeserializationOptions? options = null,
+        Vector2 offset = default,
+        Angle rot = default)
+    {
+        grid = null;
+        map = null;
+        if (!TryGetReader(file.ToRootedPath(), out var reader))
+            return false;
+
+        using (reader)
+        {
+            return TryLoadGrid(reader, file.ToString(), out map, out grid, options, offset, rot);
+        }
+    }
+
+    /// <summary>
+    /// Tries to load a grid entity from a YAML text stream and parent it to a newly created map.
+    /// If the file does not contain exactly one grid, this will return false and delete loaded entities.
+    /// </summary>
+    public bool TryLoadGrid(
+        TextReader reader,
+        string source,
         [NotNullWhen(true)] out Entity<MapComponent>? map,
         [NotNullWhen(true)] out Entity<MapGridComponent>? grid,
         DeserializationOptions? options = null,
@@ -267,7 +368,7 @@ public sealed partial class MapLoaderSystem
         if (opts.PauseMaps)
             _mapSystem.SetPaused(mapUid, true);
 
-        if (!TryLoadGrid(mapId, path, out grid, options, offset, rot))
+        if (!TryLoadGrid(mapId, reader, source, out grid, options, offset, rot))
         {
             Del(mapUid);
             map = null;

Robust.Shared/EntitySerialization/Systems/MapLoaderSystem.LoadMap.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
+using System.IO;
 using System.Linq;
 using System.Numerics;
 using Robust.Shared.GameObjects;
@@ -15,14 +16,41 @@ namespace Robust.Shared.EntitySerialization.Systems;
 public sealed partial class MapLoaderSystem
 {
     /// <summary>
-    /// Attempts to load a file containing a single map.
-    /// If the file does not contain exactly one map, this will return false and delete all loaded entities.
+    ///     Attempts to load a YAML file containing a single map.
+    ///     If the file does not contain exactly one map, this will return false and delete all loaded entities.
     /// </summary>
     /// <remarks>
-    /// Note that this will not automatically initialize the map, unless specified via the <see cref="DeserializationOptions"/>.
+    ///     Note that this will not automatically initialize the map, unless specified via the <see cref="DeserializationOptions"/>.
     /// </remarks>
     public bool TryLoadMap(
-        ResPath path,
+        ResPath file,
+        [NotNullWhen(true)] out Entity<MapComponent>? map,
+        [NotNullWhen(true)] out HashSet<Entity<MapGridComponent>>? grids,
+        DeserializationOptions? options = null,
+        Vector2 offset = default,
+        Angle rot = default)
+    {
+        map = null;
+        grids = null;
+        if (!TryGetReader(file.ToRootedPath(), out var reader))
+            return false;
+
+        using (reader)
+        {
+            return TryLoadMap(reader, file.ToString(), out map, out grids, options, offset, rot);
+        }
+    }
+
+    /// <summary>
+    ///     Attempts to load a YAML stream containing a single map.
+    ///     If the file does not contain exactly one map, this will return false and delete all loaded entities.
+    /// </summary>
+    /// <remarks>
+    ///     Note that this will not automatically initialize the map, unless specified via the <see cref="DeserializationOptions"/>.
+    /// </remarks>
+    public bool TryLoadMap(
+        TextReader reader,
+        string source,
         [NotNullWhen(true)] out Entity<MapComponent>? map,
         [NotNullWhen(true)] out HashSet<Entity<MapGridComponent>>? grids,
         DeserializationOptions? options = null,
@@ -39,7 +67,7 @@ public sealed partial class MapLoaderSystem
 
         map = null;
         grids = null;
-        if (!TryLoadGeneric(path, out var result, opts))
+        if (!TryLoadGeneric(reader, source, out var result, opts))
             return false;
 
         if (result.Maps.Count == 1)
@@ -54,17 +82,47 @@ public sealed partial class MapLoaderSystem
     }
 
     /// <summary>
-    /// Attempts to load a file containing a single map, assign it the given map id.
+    ///     Attempts to load a YAML file containing a single map, assign it the given map id.
     /// </summary>
     /// <remarks>
-    /// If possible, it is better to use <see cref="TryLoadMap"/> which automatically assigns a <see cref="MapId"/>.
+    ///     If possible, it is better to use <see cref="TryLoadMap"/> which automatically assigns a <see cref="MapId"/>.
     /// </remarks>
     /// <remarks>
-    /// Note that this will not automatically initialize the map, unless specified via the <see cref="DeserializationOptions"/>.
+    ///     Note that this will not automatically initialize the map, unless specified via the <see cref="DeserializationOptions"/>.
     /// </remarks>
     public bool TryLoadMapWithId(
         MapId mapId,
-        ResPath path,
+        ResPath file,
+        [NotNullWhen(true)] out Entity<MapComponent>? map,
+        [NotNullWhen(true)] out HashSet<Entity<MapGridComponent>>? grids,
+        DeserializationOptions? options = null,
+        Vector2 offset = default,
+        Angle rot = default)
+    {
+        map = null;
+        grids = null;
+        if (!TryGetReader(file.ToRootedPath(), out var reader))
+            return false;
+
+        using (reader)
+        {
+            return TryLoadMapWithId(mapId, reader, file.ToString(), out map, out grids, options, offset, rot);
+        }
+    }
+
+    /// <summary>
+    ///     Attempts to load a YAML text stream containing a single map, assign it the given map id.
+    /// </summary>
+    /// <remarks>
+    ///     If possible, it is better to use <see cref="TryLoadMap"/> which automatically assigns a <see cref="MapId"/>.
+    /// </remarks>
+    /// <remarks>
+    ///     Note that this will not automatically initialize the map, unless specified via the <see cref="DeserializationOptions"/>.
+    /// </remarks>
+    public bool TryLoadMapWithId(
+        MapId mapId,
+        TextReader reader,
+        string source,
         [NotNullWhen(true)] out Entity<MapComponent>? map,
         [NotNullWhen(true)] out HashSet<Entity<MapGridComponent>>? grids,
         DeserializationOptions? options = null,
@@ -86,7 +144,7 @@ public sealed partial class MapLoaderSystem
             throw new Exception($"Target map already exists");
 
         opts.ForceMapId = mapId;
-        if (!TryLoadGeneric(path, out var result, opts))
+        if (!TryLoadGeneric(reader, source, out var result, opts))
             return false;
 
         if (!_mapSystem.TryGetMap(mapId, out var uid) || !TryComp(uid, out MapComponent? comp))
@@ -98,12 +156,35 @@ public sealed partial class MapLoaderSystem
     }
 
     /// <summary>
-    /// Attempts to load a file containing a single map, and merge its children onto another map. After which the
-    /// loaded map gets deleted.
+    ///     Attempts to load a YAML text stream containing a single map, and merge its children onto another map. After which
+    ///     the loaded map gets deleted.
     /// </summary>
     public bool TryMergeMap(
         MapId mapId,
-        ResPath path,
+        ResPath file,
+        [NotNullWhen(true)] out HashSet<Entity<MapGridComponent>>? grids,
+        DeserializationOptions? options = null,
+        Vector2 offset = default,
+        Angle rot = default)
+    {
+        grids = null;
+        if (!TryGetReader(file.ToRootedPath(), out var reader))
+            return false;
+
+        using (reader)
+        {
+            return TryMergeMap(mapId, reader, file.ToString(), out grids, options, offset, rot);
+        }
+    }
+
+    /// <summary>
+    ///     Attempts to load a YAML file containing a single map, and merge its children onto another map. After which
+    ///     the loaded map gets deleted.
+    /// </summary>
+    public bool TryMergeMap(
+        MapId mapId,
+        TextReader reader,
+        string source,
         [NotNullWhen(true)] out HashSet<Entity<MapGridComponent>>? grids,
         DeserializationOptions? options = null,
         Vector2 offset = default,
@@ -123,7 +204,7 @@ public sealed partial class MapLoaderSystem
             throw new Exception($"Target map {mapId} does not exist");
 
         opts.MergeMap = mapId;
-        if (!TryLoadGeneric(path, out var result, opts))
+        if (!TryLoadGeneric(reader, source, out var result, opts))
             return false;
 
         if (!_mapSystem.TryGetMap(mapId, out var uid) || !TryComp(uid, out MapComponent? comp))

Robust.Shared/EntitySerialization/Systems/MapLoaderSystem.Save.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
+using System.IO;
 using System.Linq;
 using Robust.Shared.GameObjects;
 using Robust.Shared.Map;
@@ -59,10 +60,19 @@ public sealed partial class MapLoaderSystem
     }
 
     /// <summary>
-    /// Serialize a standard (non-grid, non-map) entity and all of its children and write the result to a
-    /// yaml file.
+    ///     Serialize a standard (non-grid, non-map) entity and all of its children and write the result to a YAML file.
     /// </summary>
-    public bool TrySaveEntity(EntityUid entity, ResPath path, SerializationOptions? options = null)
+    public bool TrySaveEntity(EntityUid entity, ResPath target, SerializationOptions? options = null)
+    {
+        using var writer = GetWriterForPath(target);
+        return TrySaveEntity(entity, writer, options);
+    }
+
+    /// <summary>
+    ///     Serialize a standard (non-grid, non-map) entity and all of its children and write the result to a YAML text
+    ///     stream.
+    /// </summary>
+    public bool TrySaveEntity(EntityUid entity, TextWriter target, SerializationOptions? options = null)
     {
         if (_mapQuery.HasComp(entity))
         {
@@ -97,12 +107,12 @@ public sealed partial class MapLoaderSystem
             return false;
         }
 
-        Write(path, data);
+        Write(target, data);
         return true;
     }
 
     /// <summary>
-    /// Serialize a map and all of its children and write the result to a yaml file.
+    /// Serialize a map and all of its children and write the result to a YAML file.
     /// </summary>
     public bool TrySaveMap(MapId mapId, ResPath path, SerializationOptions? options = null)
     {
@@ -114,9 +124,18 @@ public sealed partial class MapLoaderSystem
     }
 
     /// <summary>
-    /// Serialize a map and all of its children and write the result to a yaml file.
+    ///     Serialize a map and all of its children and write the result to a YAML file.
     /// </summary>
-    public bool TrySaveMap(EntityUid map, ResPath path, SerializationOptions? options = null)
+    public bool TrySaveMap(EntityUid map, ResPath target, SerializationOptions? options = null)
+    {
+        using var writer = GetWriterForPath(target);
+        return TrySaveMap(map, writer, options);
+    }
+
+    /// <summary>
+    ///     Serialize a map and all of its children and write the result to a YAML text stream.
+    /// </summary>
+    public bool TrySaveMap(EntityUid map, TextWriter target, SerializationOptions? options = null)
     {
         if (!_mapQuery.HasComp(map))
         {
@@ -145,14 +164,23 @@ public sealed partial class MapLoaderSystem
             return false;
         }
 
-        Write(path, data);
+        Write(target, data);
         return true;
     }
 
     /// <summary>
-    /// Serialize a grid and all of its children and write the result to a yaml file.
+    ///     Serialize a grid and all of its children and write the result to a YAML file.
     /// </summary>
-    public bool TrySaveGrid(EntityUid grid, ResPath path, SerializationOptions? options = null)
+    public bool TrySaveGrid(EntityUid map, ResPath target, SerializationOptions? options = null)
+    {
+        using var writer = GetWriterForPath(target);
+        return TrySaveGrid(map, writer, options);
+    }
+
+    /// <summary>
+    ///     Serialize a grid and all of its children and write the result to a YAML text stream.
+    /// </summary>
+    public bool TrySaveGrid(EntityUid grid, TextWriter target, SerializationOptions? options = null)
     {
         if (!_gridQuery.HasComp(grid))
         {
@@ -187,32 +215,62 @@ public sealed partial class MapLoaderSystem
             return false;
         }
 
-        Write(path, data);
+        Write(target, data);
         return true;
     }
 
     /// <summary>
-    /// Serialize an entities and all of their children to a yaml file.
-    /// This makes no assumptions about the expected entity or resulting file category.
-    /// If possible, use the map/grid specific variants instead.
+    ///     Serialize an entity and all of their children to a YAML file.
+    ///     This makes no assumptions about the expected entity or resulting file category.
+    ///     If possible, use the map/grid specific variants instead.
     /// </summary>
     public bool TrySaveGeneric(
         EntityUid uid,
-        ResPath path,
+        ResPath target,
         out FileCategory category,
         SerializationOptions? options = null)
     {
-        return TrySaveGeneric([uid], path, out category, options);
+        using var writer = GetWriterForPath(target);
+        return TrySaveGeneric(uid, writer, out category, options);
     }
 
     /// <summary>
-    /// Serialize one or more entities and all of their children to a yaml file.
-    /// This makes no assumptions about the expected entity or resulting file category.
-    /// If possible, use the map/grid specific variants instead.
+    ///     Serialize an entity and all of their children to a YAML text stream.
+    ///     This makes no assumptions about the expected entity or resulting file category.
+    ///     If possible, use the map/grid specific variants instead.
+    /// </summary>
+    public bool TrySaveGeneric(
+        EntityUid uid,
+        TextWriter target,
+        out FileCategory category,
+        SerializationOptions? options = null)
+    {
+        return TrySaveGeneric([uid], target, out category, options);
+    }
+
+    /// <summary>
+    ///     Serialize one or more entities and all of their children to a YAML file.
+    ///     This makes no assumptions about the expected entity or resulting file category.
+    ///     If possible, use the map/grid specific variants instead.
+    /// </summary>
+    public bool TrySaveGeneric(
+        HashSet<EntityUid> uid,
+        ResPath target,
+        out FileCategory category,
+        SerializationOptions? options = null)
+    {
+        using var writer = GetWriterForPath(target);
+        return TrySaveGeneric(uid, writer, out category, options);
+    }
+
+    /// <summary>
+    ///     Serialize one or more entities and all of their children to a YAML text stream.
+    ///     This makes no assumptions about the expected entity or resulting file category.
+    ///     If possible, use the map/grid specific variants instead.
     /// </summary>
     public bool TrySaveGeneric(
         HashSet<EntityUid> entities,
-        ResPath path,
+        TextWriter target,
         out FileCategory category,
         SerializationOptions? options = null)
     {
@@ -233,10 +291,21 @@ public sealed partial class MapLoaderSystem
             return false;
         }
 
-        Write(path, data);
+        Write(target, data);
         return true;
     }
 
+    /// <inheritdoc cref="TrySerializeAllEntities(out MappingDataNode, SerializationOptions?)"/>
+    public bool TrySaveAllEntities(TextWriter target, SerializationOptions? options = null)
+    {
+        if (!TrySerializeAllEntities(out var data, options))
+            return false;
+
+        Write(target, data);
+        return true;
+    }
+
+
     /// <inheritdoc cref="TrySerializeAllEntities(out MappingDataNode, SerializationOptions?)"/>
     public bool TrySaveAllEntities(ResPath path, SerializationOptions? options = null)
     {

Robust.Shared/EntitySerialization/Systems/MapLoaderSystem.cs

@@ -42,17 +42,29 @@ public sealed partial class MapLoaderSystem : EntitySystem
         _gridQuery = GetEntityQuery<MapGridComponent>();
     }
 
+    private void Write(TextWriter target, MappingDataNode data)
+    {
+        var document = new YamlDocument(data.ToYaml());
+        var stream = new YamlStream {document};
+        stream.Save(new YamlMappingFix(new Emitter(target)), false);
+    }
+
+    private StreamWriter GetWriterForPath(ResPath path)
+    {
+        Log.Info($"Saving serialized results to {path}");
+        path = path.ToRootedPath();
+        _resourceManager.UserData.CreateDir(path.Directory);
+        return _resourceManager.UserData.OpenWriteText(path);
+    }
+
     private void Write(ResPath path, MappingDataNode data)
     {
         Log.Info($"Saving serialized results to {path}");
         path = path.ToRootedPath();
-        var document = new YamlDocument(data.ToYaml());
         _resourceManager.UserData.CreateDir(path.Directory);
         using var writer = _resourceManager.UserData.OpenWriteText(path);
-        {
-            var stream = new YamlStream {document};
-            stream.Save(new YamlMappingFix(new Emitter(writer)), false);
-        }
+
+        Write(writer, data);
     }
 
     public bool TryReadFile(ResPath file, [NotNullWhen(true)] out MappingDataNode? data)

Robust.Shared/GameObjects/Components/UserInterface/BoundUserInterface.cs

@@ -32,7 +32,8 @@ namespace Robust.Shared.GameObjects
 
         protected BoundUserInterface(EntityUid owner, Enum uiKey)
         {
-            IoCManager.InjectDependencies(this);
+            IoCManager.Resolve(ref EntMan);
+            EntMan.EntitySysManager.DependencyCollection.InjectDependencies(this);
             UiSystem = EntMan.System<SharedUserInterfaceSystem>();
 
             Owner = owner;

Robust.Shared/GameObjects/EntityManager.Components.cs

@@ -838,18 +838,16 @@ namespace Robust.Shared.GameObjects
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public bool EnsureComponent<T>(ref Entity<T?> entity) where T : IComponent, new()
         {
-            if (entity.Comp != null)
-            {
-                // Check for deferred component removal.
-                if (entity.Comp.LifeStage <= ComponentLifeStage.Running)
-                {
-                    DebugTools.AssertOwner(entity, entity.Comp);
-                    return true;
-                }
+            if (entity.Comp == null)
+                return EnsureComponent<T>(entity.Owner, out entity.Comp);
 
-                RemoveComponent(entity, entity.Comp);
-            }
+            DebugTools.AssertOwner(entity, entity.Comp);
 
+            // Check for deferred component removal.
+            if (entity.Comp.LifeStage <= ComponentLifeStage.Running)
+                return true;
+
+            RemoveComponent(entity, entity.Comp);
             entity.Comp = AddComponent<T>(entity);
             return false;
         }