Reformat code

Caused by 72ddaf91.

.config/dotnet-tools.json

@@ -3,7 +3,7 @@
   "isRoot": true,
   "tools": {
     "dotnet-ef": {
-      "version": "7.0.0-rc.1.22426.7",
+      "version": "8.0.3",
       "commands": [
         "dotnet-ef"
       ]

Agent/Phantom.Agent.Minecraft/Launcher/BaseLauncher.cs

@@ -105,7 +105,7 @@ public abstract class BaseLauncher : IServerLauncher {
 	
 	private static async Task AcceptEula(InstanceProperties instanceProperties) {
 		var eulaFilePath = Path.Combine(instanceProperties.InstanceFolder, "eula.txt");
-		await File.WriteAllLinesAsync(eulaFilePath, new [] { "# EULA", "eula=true" }, Encoding.UTF8);
+		await File.WriteAllLinesAsync(eulaFilePath, new[] { "# EULA", "eula=true" }, Encoding.UTF8);
 	}
 	
 	private static async Task UpdateServerProperties(InstanceProperties instanceProperties) {

Agent/Phantom.Agent.Minecraft/Properties/MinecraftServerProperties.cs

@@ -18,4 +18,5 @@ static class MinecraftServerProperties {
 	public static readonly MinecraftServerProperty<ushort> ServerPort = new UnsignedShort("server-port");
 	public static readonly MinecraftServerProperty<ushort> RconPort = new UnsignedShort("rcon.port");
 	public static readonly MinecraftServerProperty<bool> EnableRcon = new Boolean("enable-rcon");
+	public static readonly MinecraftServerProperty<bool> SyncChunkWrites = new Boolean("sync-chunk-writes");
 }

Agent/Phantom.Agent.Minecraft/Properties/ServerProperties.cs

@@ -5,11 +5,13 @@ namespace Phantom.Agent.Minecraft.Properties;
 public sealed record ServerProperties(
 	ushort ServerPort,
 	ushort RconPort,
-	bool EnableRcon = true
+	bool EnableRcon = true,
+	bool SyncChunkWrites = false
 ) {
 	internal void SetTo(JavaPropertiesFileEditor properties) {
 		MinecraftServerProperties.ServerPort.Set(properties, ServerPort);
 		MinecraftServerProperties.RconPort.Set(properties, RconPort);
 		MinecraftServerProperties.EnableRcon.Set(properties, EnableRcon);
+		MinecraftServerProperties.SyncChunkWrites.Set(properties, SyncChunkWrites);
 	}
 }

Agent/Phantom.Agent.Minecraft/Server/MinecraftServerExecutableDownloader.cs

@@ -16,32 +16,47 @@ sealed class MinecraftServerExecutableDownloader {
 	public event EventHandler? Completed;
 	
 	private readonly CancellationTokenSource cancellationTokenSource = new ();
-	private int listeners = 0;
+	
+	private readonly List<CancellationTokenRegistration> listenerCancellationRegistrations = new ();
+	private int listenerCount = 0;
 	
 	public MinecraftServerExecutableDownloader(FileDownloadInfo fileDownloadInfo, string minecraftVersion, string filePath, MinecraftServerExecutableDownloadListener listener) {
 		Register(listener);
-		Task = DownloadAndGetPath(fileDownloadInfo, minecraftVersion, filePath);
+		Task = DownloadAndGetPath(fileDownloadInfo, minecraftVersion, filePath, new DownloadProgressCallback(this), cancellationTokenSource.Token);
 		Task.ContinueWith(OnCompleted, TaskScheduler.Default);
 	}
 	
 	public void Register(MinecraftServerExecutableDownloadListener listener) {
-		++listeners;
+		int newListenerCount;
-		Logger.Debug("Registered download listener, current listener count: {Listeners}", listeners);
+		
+		lock (this) {
+			newListenerCount = ++listenerCount;
 			
 			DownloadProgress += listener.DownloadProgressEventHandler;
-		listener.CancellationToken.Register(Unregister, listener);
+			listenerCancellationRegistrations.Add(listener.CancellationToken.Register(Unregister, listener));
+		}
+		
+		Logger.Debug("Registered download listener, current listener count: {Listeners}", newListenerCount);
 	}
 	
 	private void Unregister(object? listenerObject) {
+		int newListenerCount;
+		
+		lock (this) {
 			MinecraftServerExecutableDownloadListener listener = (MinecraftServerExecutableDownloadListener) listenerObject!;
 			DownloadProgress -= listener.DownloadProgressEventHandler;
 			
-		if (--listeners <= 0) {
+			newListenerCount = --listenerCount;
-			Logger.Debug("Unregistered last download listener, cancelling download.");
+			if (newListenerCount <= 0) {
 				cancellationTokenSource.Cancel();
 			}
+		}
+		
+		if (newListenerCount <= 0) {
+			Logger.Debug("Unregistered last download listener, cancelling download.");
+		}
 		else {
-			Logger.Debug("Unregistered download listener, current listener count: {Listeners}", listeners);
+			Logger.Debug("Unregistered download listener, current listener count: {Listeners}", newListenerCount);
 		}
 	}
 	
@@ -51,9 +66,19 @@ sealed class MinecraftServerExecutableDownloader {
 	
 	private void OnCompleted(Task task) {
 		Logger.Debug("Download task completed.");
+		
+		lock (this) {
 			Completed?.Invoke(this, EventArgs.Empty);
 			Completed = null;
 			DownloadProgress = null;
+			
+			foreach (var registration in listenerCancellationRegistrations) {
+				registration.Dispose();
+			}
+			
+			listenerCancellationRegistrations.Clear();
+			cancellationTokenSource.Dispose();
+		}
 	}
 	
 	private sealed class DownloadProgressCallback {
@@ -68,15 +93,14 @@ sealed class MinecraftServerExecutableDownloader {
 		}
 	}
 	
-	private async Task<string?> DownloadAndGetPath(FileDownloadInfo fileDownloadInfo, string minecraftVersion, string filePath) {
+	private static async Task<string?> DownloadAndGetPath(FileDownloadInfo fileDownloadInfo, string minecraftVersion, string filePath, DownloadProgressCallback progressCallback, CancellationToken cancellationToken) {
 		string tmpFilePath = filePath + ".tmp";
 		
-		var cancellationToken = cancellationTokenSource.Token;
 		try {
 			Logger.Information("Downloading server version {Version} from: {Url} ({Size})", minecraftVersion, fileDownloadInfo.DownloadUrl, fileDownloadInfo.Size.ToHumanReadable(decimalPlaces: 1));
 			try {
 				using var http = new HttpClient();
-				await FetchServerExecutableFile(http, new DownloadProgressCallback(this), fileDownloadInfo, tmpFilePath, cancellationToken);
+				await FetchServerExecutableFile(http, progressCallback, fileDownloadInfo, tmpFilePath, cancellationToken);
 			} catch (Exception) {
 				TryDeleteExecutableAfterFailure(tmpFilePath);
 				throw;
@@ -94,8 +118,6 @@ sealed class MinecraftServerExecutableDownloader {
 		} catch (Exception e) {
 			Logger.Error(e, "An unexpected error occurred.");
 			return null;
-		} finally {
-			cancellationTokenSource.Dispose();
 		}
 	}
 	

Agent/Phantom.Agent.Minecraft/Server/ServerStatusProtocol.cs

@@ -3,28 +3,12 @@ using System.Buffers.Binary;
 using System.Net;
 using System.Net.Sockets;
 using System.Text;
-using Phantom.Utils.Logging;
+using Phantom.Common.Data.Instance;
-using Serilog;
 
 namespace Phantom.Agent.Minecraft.Server;
 
-public sealed class ServerStatusProtocol {
+public static class ServerStatusProtocol {
-	private readonly ILogger logger;
+	public static async Task<InstancePlayerCounts> GetPlayerCounts(ushort serverPort, CancellationToken cancellationToken) {
-
-	public ServerStatusProtocol(string loggerName) {
-		this.logger = PhantomLogger.Create<ServerStatusProtocol>(loggerName);
-	}
-
-	public async Task<int?> GetOnlinePlayerCount(int serverPort, CancellationToken cancellationToken) {
-		try {
-			return await GetOnlinePlayerCountOrThrow(serverPort, cancellationToken);
-		} catch (Exception e) {
-			logger.Error(e, "Caught exception while checking if players are online.");
-			return null;
-		}
-	}
-
-	private async Task<int?> GetOnlinePlayerCountOrThrow(int serverPort, CancellationToken cancellationToken) {
 		using var tcpClient = new TcpClient();
 		await tcpClient.ConnectAsync(IPAddress.Loopback, serverPort, cancellationToken);
 		var tcpStream = tcpClient.GetStream();
@@ -33,24 +17,22 @@ public sealed class ServerStatusProtocol {
 		tcpStream.WriteByte(0xFE);
 		await tcpStream.FlushAsync(cancellationToken);
 		
-		short? messageLength = await ReadStreamHeader(tcpStream, cancellationToken);
+		short messageLength = await ReadStreamHeader(tcpStream, cancellationToken);
-		return messageLength == null ? null : await ReadOnlinePlayerCount(tcpStream, messageLength.Value * 2, cancellationToken);
+		return await ReadPlayerCounts(tcpStream, messageLength * 2, cancellationToken);
 	}
 	
-	private async Task<short?> ReadStreamHeader(NetworkStream tcpStream, CancellationToken cancellationToken) {
+	private static async Task<short> ReadStreamHeader(NetworkStream tcpStream, CancellationToken cancellationToken) {
 		var headerBuffer = ArrayPool<byte>.Shared.Rent(3);
 		try {
 			await tcpStream.ReadExactlyAsync(headerBuffer, 0, 3, cancellationToken);
 			
 			if (headerBuffer[0] != 0xFF) {
-				logger.Error("Unexpected first byte in response from server: {FirstByte}.", headerBuffer[0]);
+				throw new ProtocolException("Unexpected first byte in response from server: " + headerBuffer[0]);
-				return null;
 			}
 			
 			short messageLength = BinaryPrimitives.ReadInt16BigEndian(headerBuffer.AsSpan(1));
 			if (messageLength <= 0) {
-				logger.Error("Unexpected message length in response from server: {MessageLength}.", messageLength);
+				throw new ProtocolException("Unexpected message length in response from server: " + messageLength);
-				return null;
 			}
 			
 			return messageLength;
@@ -59,35 +41,54 @@ public sealed class ServerStatusProtocol {
 		}
 	}
 	
-	private async Task<int?> ReadOnlinePlayerCount(NetworkStream tcpStream, int messageLength, CancellationToken cancellationToken) {
+	private static async Task<InstancePlayerCounts> ReadPlayerCounts(NetworkStream tcpStream, int messageLength, CancellationToken cancellationToken) {
 		var messageBuffer = ArrayPool<byte>.Shared.Rent(messageLength);
 		try {
 			await tcpStream.ReadExactlyAsync(messageBuffer, 0, messageLength, cancellationToken);
-
+			return ReadPlayerCountsFromResponse(messageBuffer.AsSpan(0, messageLength));
-			// Valid response separator encoded in UTF-16BE is 0x00 0xA7 (§).
-			const byte SeparatorSecondByte = 0xA7;
-			
-			static bool IsValidSeparator(ReadOnlySpan<byte> buffer, int index) {
-				return index > 0 && buffer[index - 1] == 0x00;
-			}
-			
-			int separator2 = Array.LastIndexOf(messageBuffer, SeparatorSecondByte);
-			int separator1 = separator2 == -1 ? -1 : Array.LastIndexOf(messageBuffer, SeparatorSecondByte, separator2 - 1);
-			if (!IsValidSeparator(messageBuffer, separator1) || !IsValidSeparator(messageBuffer, separator2)) {
-				logger.Error("Could not find message separators in response from server.");
-				return null;
-			}
-
-			string onlinePlayerCountStr = Encoding.BigEndianUnicode.GetString(messageBuffer.AsSpan((separator1 + 1)..(separator2 - 1)));
-			if (!int.TryParse(onlinePlayerCountStr, out int onlinePlayerCount)) {
-				logger.Error("Could not parse online player count in response from server: {OnlinePlayerCount}.", onlinePlayerCountStr);
-				return null;
-			}
-			
-			logger.Debug("Detected {OnlinePlayerCount} online player(s).", onlinePlayerCount);
-			return onlinePlayerCount;
 		} finally {
 			ArrayPool<byte>.Shared.Return(messageBuffer);
 		}
 	}
+	
+	/// <summary>
+	/// Legacy query protocol uses the paragraph symbol (§) as separator encoded in UTF-16BE.
+	/// </summary>
+	private static readonly byte[] Separator = { 0x00, 0xA7 };
+	
+	private static InstancePlayerCounts ReadPlayerCountsFromResponse(ReadOnlySpan<byte> messageBuffer) {
+		int lastSeparator = messageBuffer.LastIndexOf(Separator);
+		int middleSeparator = messageBuffer[..lastSeparator].LastIndexOf(Separator);
+		
+		if (lastSeparator == -1 || middleSeparator == -1) {
+			throw new ProtocolException("Could not find message separators in response from server.");
+		}
+		
+		var onlinePlayerCountBuffer = messageBuffer[(middleSeparator + Separator.Length)..lastSeparator];
+		var maximumPlayerCountBuffer = messageBuffer[(lastSeparator + Separator.Length)..];
+		
+		// Player counts are integers, whose maximum string length is 10 characters.
+		Span<char> integerStringBuffer = stackalloc char[10];
+		
+		return new InstancePlayerCounts(
+			DecodeAndParsePlayerCount(onlinePlayerCountBuffer, integerStringBuffer, "online"),
+			DecodeAndParsePlayerCount(maximumPlayerCountBuffer, integerStringBuffer, "maximum")
+		);
+	}
+	
+	private static int DecodeAndParsePlayerCount(ReadOnlySpan<byte> inputBuffer, Span<char> tempCharBuffer, string countType) {
+		if (!Encoding.BigEndianUnicode.TryGetChars(inputBuffer, tempCharBuffer, out int charCount)) {
+			throw new ProtocolException("Could not decode " + countType + " player count in response from server.");
+		}
+		
+		if (!int.TryParse(tempCharBuffer, out int playerCount)) {
+			throw new ProtocolException("Could not parse " + countType + " player count in response from server: " + tempCharBuffer[..charCount].ToString());
+		}
+		
+		return playerCount;
+	}
+	
+	public sealed class ProtocolException : Exception {
+		internal ProtocolException(string message) : base(message) {}
+	}
 }

Agent/Phantom.Agent.Services/Backups/BackupManager.cs

@@ -67,6 +67,10 @@ sealed class BackupManager : IDisposable {
 				resultBuilder.Kind = BackupCreationResultKind.BackupCancelled;
 				logger.Warning("Backup creation was cancelled.");
 				return null;
+			} catch (TimeoutException) {
+				resultBuilder.Kind = BackupCreationResultKind.BackupTimedOut;
+				logger.Warning("Backup creation timed out.");
+				return null;
 			} catch (Exception e) {
 				resultBuilder.Kind = BackupCreationResultKind.UnknownError;
 				logger.Error(e, "Caught exception while creating an instance backup.");
@@ -76,6 +80,9 @@ sealed class BackupManager : IDisposable {
 					await dispatcher.EnableAutomaticSaving();
 				} catch (OperationCanceledException) {
 					// Ignore.
+				} catch (TimeoutException) {
+					resultBuilder.Warnings |= BackupCreationWarnings.CouldNotRestoreAutomaticSaving;
+					logger.Warning("Timed out waiting for automatic saving to be re-enabled.");
 				} catch (Exception e) {
 					resultBuilder.Warnings |= BackupCreationWarnings.CouldNotRestoreAutomaticSaving;
 					logger.Error(e, "Caught exception while enabling automatic saving after creating an instance backup.");
@@ -120,6 +127,7 @@ sealed class BackupManager : IDisposable {
 				BackupCreationResultKind.Success                            => "Backup created successfully.",
 				BackupCreationResultKind.InstanceNotRunning                 => "Instance is not running.",
 				BackupCreationResultKind.BackupCancelled                    => "Backup cancelled.",
+				BackupCreationResultKind.BackupTimedOut                     => "Backup timed out.",
 				BackupCreationResultKind.BackupAlreadyRunning               => "A backup is already being created.",
 				BackupCreationResultKind.BackupFileAlreadyExists            => "Backup with the same name already exists.",
 				BackupCreationResultKind.CouldNotCreateBackupFolder         => "Could not create backup folder.",

Agent/Phantom.Agent.Services/Backups/BackupScheduler.cs

@@ -1,10 +1,8 @@
-using Phantom.Agent.Minecraft.Instance;
+using Phantom.Agent.Services.Instances;
-using Phantom.Agent.Minecraft.Server;
+using Phantom.Agent.Services.Instances.State;
-using Phantom.Agent.Services.Instances;
 using Phantom.Common.Data.Backups;
 using Phantom.Utils.Logging;
 using Phantom.Utils.Tasks;
-using Phantom.Utils.Threading;
 
 namespace Phantom.Agent.Services.Backups;
 
@@ -16,20 +14,16 @@ sealed class BackupScheduler : CancellableBackgroundTask {
 	
 	private readonly BackupManager backupManager;
 	private readonly InstanceContext context;
-	private readonly InstanceProcess process;
 	private readonly SemaphoreSlim backupSemaphore = new (1, 1);
-	private readonly int serverPort;
-	private readonly ServerStatusProtocol serverStatusProtocol;
 	private readonly ManualResetEventSlim serverOutputWhileWaitingForOnlinePlayers = new ();
+	private readonly InstancePlayerCountTracker playerCountTracker;
 	
 	public event EventHandler<BackupCreationResult>? BackupCompleted;
 	
-	public BackupScheduler(InstanceContext context, InstanceProcess process, int serverPort) : base(PhantomLogger.Create<BackupScheduler>(context.ShortName)) {
+	public BackupScheduler(InstanceContext context, InstancePlayerCountTracker playerCountTracker) : base(PhantomLogger.Create<BackupScheduler>(context.ShortName)) {
 		this.backupManager = context.Services.BackupManager;
 		this.context = context;
-		this.process = process;
+		this.playerCountTracker = playerCountTracker;
-		this.serverPort = serverPort;
-		this.serverStatusProtocol = new ServerStatusProtocol(context.ShortName);
 		Start();
 	}
 	
@@ -69,43 +63,18 @@ sealed class BackupScheduler : CancellableBackgroundTask {
 	}
 	
 	private async Task WaitForOnlinePlayers() {
-		bool needsToLogOfflinePlayersMessage = true;
+		var task = playerCountTracker.WaitForOnlinePlayers(CancellationToken);
+		if (!task.IsCompleted) {
+			Logger.Information("Waiting for someone to join before starting a new backup.");
+		}
 		
-		process.AddOutputListener(ServerOutputListener, maxLinesToReadFromHistory: 0);
 		try {
-			while (!CancellationToken.IsCancellationRequested) {
+			await task;
-				serverOutputWhileWaitingForOnlinePlayers.Reset();
-				
-				var onlinePlayerCount = await serverStatusProtocol.GetOnlinePlayerCount(serverPort, CancellationToken);
-				if (onlinePlayerCount == null) {
-					Logger.Warning("Could not detect whether any players are online, starting a new backup.");
-					break;
-				}
-
-				if (onlinePlayerCount > 0) {
 			Logger.Information("Players are online, starting a new backup.");
-					break;
+		} catch (OperationCanceledException) {
-				}
+			throw;
-
+		} catch (Exception) {
-				if (needsToLogOfflinePlayersMessage) {
+			Logger.Warning("Could not detect whether any players are online, starting a new backup.");
-					needsToLogOfflinePlayersMessage = false;
-					Logger.Information("No players are online, waiting for someone to join before starting a new backup.");
-				}
-
-				await Task.Delay(TimeSpan.FromSeconds(10), CancellationToken);
-				
-				Logger.Debug("Waiting for server output before checking for online players again...");
-				await serverOutputWhileWaitingForOnlinePlayers.WaitHandle.WaitOneAsync(CancellationToken);
-			}
-		} finally {
-			process.RemoveOutputListener(ServerOutputListener);
-		}
-	}
-
-	private void ServerOutputListener(object? sender, string line) {
-		if (!serverOutputWhileWaitingForOnlinePlayers.IsSet) {
-			serverOutputWhileWaitingForOnlinePlayers.Set();
-			Logger.Debug("Detected server output, signalling to check for online players again.");
 		}
 	}
 	

Agent/Phantom.Agent.Services/Backups/BackupServerCommandDispatcher.cs

@@ -1,4 +1,5 @@
-using System.Text.RegularExpressions;
+using System.Collections.Immutable;
+using System.Text.RegularExpressions;
 using Phantom.Agent.Minecraft.Command;
 using Phantom.Agent.Minecraft.Instance;
 using Phantom.Utils.Tasks;
@@ -7,9 +8,27 @@ using Serilog;
 namespace Phantom.Agent.Services.Backups;
 
 sealed partial class BackupServerCommandDispatcher : IDisposable {
-	[GeneratedRegex(@"^\[(?:.*?)\] \[Server thread/INFO\]: (.*?)$", RegexOptions.NonBacktracking)]
+	[GeneratedRegex(@"^(?:(?:\[.*?\] \[Server thread/INFO\].*?:)|(?:[\d-]+? [\d:]+? \[INFO\])) (.*?)$", RegexOptions.NonBacktracking)]
 	private static partial Regex ServerThreadInfoRegex();
 	
+	private static readonly ImmutableHashSet<string> AutomaticSavingDisabledMessages = ImmutableHashSet.Create(
+		"Automatic saving is now disabled",
+		"Turned off world auto-saving",
+		"CONSOLE: Disabling level saving.."
+	);
+	
+	private static readonly ImmutableHashSet<string> SavedTheGameMessages = ImmutableHashSet.Create(
+		"Saved the game",
+		"Saved the world",
+		"CONSOLE: Save complete."
+	);
+	
+	private static readonly ImmutableHashSet<string> AutomaticSavingEnabledMessages = ImmutableHashSet.Create(
+		"Automatic saving is now enabled",
+		"Turned on world auto-saving",
+		"CONSOLE: Enabling level saving.."
+	);
+	
 	private readonly ILogger logger;
 	private readonly InstanceProcess process;
 	private readonly CancellationToken cancellationToken;
@@ -32,18 +51,17 @@ sealed partial class BackupServerCommandDispatcher : IDisposable {
 	
 	public async Task DisableAutomaticSaving() {
 		await process.SendCommand(MinecraftCommand.SaveOff, cancellationToken);
-		await automaticSavingDisabled.Task.WaitAsync(cancellationToken);
+		await automaticSavingDisabled.Task.WaitAsync(TimeSpan.FromSeconds(30), cancellationToken);
 	}
 	
 	public async Task SaveAllChunks() {
-		// TODO Try if not flushing and waiting a few seconds before flushing reduces lag.
 		await process.SendCommand(MinecraftCommand.SaveAll(flush: true), cancellationToken);
-		await savedTheGame.Task.WaitAsync(cancellationToken);
+		await savedTheGame.Task.WaitAsync(TimeSpan.FromMinutes(1), cancellationToken);
 	}
 	
 	public async Task EnableAutomaticSaving() {
 		await process.SendCommand(MinecraftCommand.SaveOn, cancellationToken);
-		await automaticSavingEnabled.Task.WaitAsync(cancellationToken);
+		await automaticSavingEnabled.Task.WaitAsync(TimeSpan.FromMinutes(1), cancellationToken);
 	}
 	
 	private void OnOutput(object? sender, string? line) {
@@ -59,19 +77,19 @@ sealed partial class BackupServerCommandDispatcher : IDisposable {
 		string info = match.Groups[1].Value;
 		
 		if (!automaticSavingDisabled.Task.IsCompleted) {
-			if (info == "Automatic saving is now disabled") {
+			if (AutomaticSavingDisabledMessages.Contains(info)) {
 				logger.Debug("Detected that automatic saving is disabled.");
 				automaticSavingDisabled.SetResult();
 			}
 		}
 		else if (!savedTheGame.Task.IsCompleted) {
-			if (info == "Saved the game") {
+			if (SavedTheGameMessages.Contains(info)) {
 				logger.Debug("Detected that the game is saved.");
 				savedTheGame.SetResult();
 			}
 		}
 		else if (!automaticSavingEnabled.Task.IsCompleted) {
-			if (info == "Automatic saving is now enabled") {
+			if (AutomaticSavingEnabledMessages.Contains(info)) {
 				logger.Debug("Detected that automatic saving is enabled.");
 				automaticSavingEnabled.SetResult();
 			}

Agent/Phantom.Agent.Services/Instances/InstanceActor.cs

@@ -135,7 +135,12 @@ sealed class InstanceActor : ReceiveActor<InstanceActor.ICommand> {
 			return new BackupCreationResult(BackupCreationResultKind.InstanceNotRunning);
 		}
 		else {
+			SetAndReportStatus(InstanceStatus.BackingUp);
+			try {
 				return await command.BackupManager.CreateBackup(context.ShortName, runningState.Process, shutdownCancellationToken);
+			} finally {
+				SetAndReportStatus(InstanceStatus.Running);
+			}
 		}
 	}
 	

Agent/Phantom.Agent.Services/Instances/InstanceManagerActor.cs

@@ -6,13 +6,13 @@ using Phantom.Agent.Minecraft.Properties;
 using Phantom.Agent.Minecraft.Server;
 using Phantom.Agent.Rpc;
 using Phantom.Agent.Services.Backups;
+using Phantom.Common.Data;
 using Phantom.Common.Data.Instance;
 using Phantom.Common.Data.Minecraft;
 using Phantom.Common.Data.Replies;
 using Phantom.Utils.Actor;
 using Phantom.Utils.IO;
 using Phantom.Utils.Logging;
-using Phantom.Utils.Tasks;
 using Serilog;
 
 namespace Phantom.Agent.Services.Instances;
@@ -49,10 +49,10 @@ sealed class InstanceManagerActor : ReceiveActor<InstanceManagerActor.ICommand>
 		
 		this.instanceServices = new InstanceServices(init.ControllerConnection, init.BackupManager, launchServices);
 		
-		ReceiveAndReply<ConfigureInstanceCommand, InstanceActionResult<ConfigureInstanceResult>>(ConfigureInstance);
+		ReceiveAndReply<ConfigureInstanceCommand, Result<ConfigureInstanceResult, InstanceActionFailure>>(ConfigureInstance);
-		ReceiveAndReply<LaunchInstanceCommand, InstanceActionResult<LaunchInstanceResult>>(LaunchInstance);
+		ReceiveAndReply<LaunchInstanceCommand, Result<LaunchInstanceResult, InstanceActionFailure>>(LaunchInstance);
-		ReceiveAndReply<StopInstanceCommand, InstanceActionResult<StopInstanceResult>>(StopInstance);
+		ReceiveAndReply<StopInstanceCommand, Result<StopInstanceResult, InstanceActionFailure>>(StopInstance);
-		ReceiveAsyncAndReply<SendCommandToInstanceCommand, InstanceActionResult<SendCommandToInstanceResult>>(SendCommandToInstance);
+		ReceiveAsyncAndReply<SendCommandToInstanceCommand, Result<SendCommandToInstanceResult, InstanceActionFailure>>(SendCommandToInstance);
 		ReceiveAsync<ShutdownCommand>(Shutdown);
 	}
 	
@@ -65,17 +65,17 @@ sealed class InstanceManagerActor : ReceiveActor<InstanceManagerActor.ICommand>
 	
 	public interface ICommand {}
 	
-	public sealed record ConfigureInstanceCommand(Guid InstanceGuid, InstanceConfiguration Configuration, InstanceLaunchProperties LaunchProperties, bool LaunchNow, bool AlwaysReportStatus) : ICommand, ICanReply<InstanceActionResult<ConfigureInstanceResult>>;
+	public sealed record ConfigureInstanceCommand(Guid InstanceGuid, InstanceConfiguration Configuration, InstanceLaunchProperties LaunchProperties, bool LaunchNow, bool AlwaysReportStatus) : ICommand, ICanReply<Result<ConfigureInstanceResult, InstanceActionFailure>>;
 	
-	public sealed record LaunchInstanceCommand(Guid InstanceGuid) : ICommand, ICanReply<InstanceActionResult<LaunchInstanceResult>>;
+	public sealed record LaunchInstanceCommand(Guid InstanceGuid) : ICommand, ICanReply<Result<LaunchInstanceResult, InstanceActionFailure>>;
 	
-	public sealed record StopInstanceCommand(Guid InstanceGuid, MinecraftStopStrategy StopStrategy) : ICommand, ICanReply<InstanceActionResult<StopInstanceResult>>;
+	public sealed record StopInstanceCommand(Guid InstanceGuid, MinecraftStopStrategy StopStrategy) : ICommand, ICanReply<Result<StopInstanceResult, InstanceActionFailure>>;
 	
-	public sealed record SendCommandToInstanceCommand(Guid InstanceGuid, string Command) : ICommand, ICanReply<InstanceActionResult<SendCommandToInstanceResult>>;
+	public sealed record SendCommandToInstanceCommand(Guid InstanceGuid, string Command) : ICommand, ICanReply<Result<SendCommandToInstanceResult, InstanceActionFailure>>;
 	
 	public sealed record ShutdownCommand : ICommand;
 	
-	private InstanceActionResult<ConfigureInstanceResult> ConfigureInstance(ConfigureInstanceCommand command) {
+	private Result<ConfigureInstanceResult, InstanceActionFailure> ConfigureInstance(ConfigureInstanceCommand command) {
 		var instanceGuid = command.InstanceGuid;
 		var configuration = command.Configuration;
 		
@@ -130,64 +130,64 @@ sealed class InstanceManagerActor : ReceiveActor<InstanceManagerActor.ICommand>
 			LaunchInstance(new LaunchInstanceCommand(instanceGuid));
 		}
 		
-		return InstanceActionResult.Concrete(ConfigureInstanceResult.Success);
+		return ConfigureInstanceResult.Success;
 	}
 	
-	private InstanceActionResult<LaunchInstanceResult> LaunchInstance(LaunchInstanceCommand command) {
+	private Result<LaunchInstanceResult, InstanceActionFailure> LaunchInstance(LaunchInstanceCommand command) {
 		var instanceGuid = command.InstanceGuid;
 		if (!instances.TryGetValue(instanceGuid, out var instanceInfo)) {
-			return InstanceActionResult.General<LaunchInstanceResult>(InstanceActionGeneralResult.InstanceDoesNotExist);
+			return InstanceActionFailure.InstanceDoesNotExist;
 		}
 		
 		var ticket = instanceTicketManager.Reserve(instanceInfo.Configuration);
-		if (ticket is Result<InstanceTicketManager.Ticket, LaunchInstanceResult>.Fail fail) {
+		if (!ticket) {
-			return InstanceActionResult.Concrete(fail.Error);
+			return ticket.Error;
 		}
 		
 		if (agentState.InstancesByGuid.TryGetValue(instanceGuid, out var instance)) {
 			var status = instance.Status;
 			if (status.IsRunning()) {
-				return InstanceActionResult.Concrete(LaunchInstanceResult.InstanceAlreadyRunning);
+				return LaunchInstanceResult.InstanceAlreadyRunning;
 			}
 			else if (status.IsLaunching()) {
-				return InstanceActionResult.Concrete(LaunchInstanceResult.InstanceAlreadyLaunching);
+				return LaunchInstanceResult.InstanceAlreadyLaunching;
 			}
 		}
 		
 		instanceInfo.Actor.Tell(new InstanceActor.LaunchInstanceCommand(instanceInfo.Configuration, instanceInfo.Launcher, ticket.Value, IsRestarting: false));
-		return InstanceActionResult.Concrete(LaunchInstanceResult.LaunchInitiated);
+		return LaunchInstanceResult.LaunchInitiated;
 	}
 	
-	private InstanceActionResult<StopInstanceResult> StopInstance(StopInstanceCommand command) {
+	private Result<StopInstanceResult, InstanceActionFailure> StopInstance(StopInstanceCommand command) {
 		var instanceGuid = command.InstanceGuid;
 		if (!instances.TryGetValue(instanceGuid, out var instanceInfo)) {
-			return InstanceActionResult.General<StopInstanceResult>(InstanceActionGeneralResult.InstanceDoesNotExist);
+			return InstanceActionFailure.InstanceDoesNotExist;
 		}
 		
 		if (agentState.InstancesByGuid.TryGetValue(instanceGuid, out var instance)) {
 			var status = instance.Status;
 			if (status.IsStopping()) {
-				return InstanceActionResult.Concrete(StopInstanceResult.InstanceAlreadyStopping);
+				return StopInstanceResult.InstanceAlreadyStopping;
 			}
 			else if (!status.CanStop()) {
-				return InstanceActionResult.Concrete(StopInstanceResult.InstanceAlreadyStopped);
+				return StopInstanceResult.InstanceAlreadyStopped;
 			}
 		}
 		
 		instanceInfo.Actor.Tell(new InstanceActor.StopInstanceCommand(command.StopStrategy));
-		return InstanceActionResult.Concrete(StopInstanceResult.StopInitiated);
+		return StopInstanceResult.StopInitiated;
 	}
 	
-	private async Task<InstanceActionResult<SendCommandToInstanceResult>> SendCommandToInstance(SendCommandToInstanceCommand command) {
+	private async Task<Result<SendCommandToInstanceResult, InstanceActionFailure>> SendCommandToInstance(SendCommandToInstanceCommand command) {
 		var instanceGuid = command.InstanceGuid;
 		if (!instances.TryGetValue(instanceGuid, out var instanceInfo)) {
-			return InstanceActionResult.General<SendCommandToInstanceResult>(InstanceActionGeneralResult.InstanceDoesNotExist);
+			return InstanceActionFailure.InstanceDoesNotExist;
 		}
 		
 		try {
-			return InstanceActionResult.Concrete(await instanceInfo.Actor.Request(new InstanceActor.SendCommandToInstanceCommand(command.Command), shutdownCancellationToken));
+			return await instanceInfo.Actor.Request(new InstanceActor.SendCommandToInstanceCommand(command.Command), shutdownCancellationToken);
 		} catch (OperationCanceledException) {
-			return InstanceActionResult.General<SendCommandToInstanceResult>(InstanceActionGeneralResult.AgentShuttingDown);
+			return InstanceActionFailure.AgentShuttingDown;
 		}
 	}
 	

Agent/Phantom.Agent.Services/Instances/InstanceTicketManager.cs

@@ -5,7 +5,6 @@ using Phantom.Common.Data.Instance;
 using Phantom.Common.Data.Replies;
 using Phantom.Common.Messages.Agent.ToController;
 using Phantom.Utils.Logging;
-using Phantom.Utils.Tasks;
 using Serilog;
 
 namespace Phantom.Agent.Services.Instances;

Agent/Phantom.Agent.Services/Instances/State/InstanceLaunchProcedure.cs

@@ -1,8 +1,8 @@
 using Phantom.Agent.Minecraft.Instance;
 using Phantom.Agent.Minecraft.Launcher;
 using Phantom.Agent.Minecraft.Server;
+using Phantom.Common.Data;
 using Phantom.Common.Data.Instance;
-using Phantom.Utils.Tasks;
 
 namespace Phantom.Agent.Services.Instances.State;
 

Agent/Phantom.Agent.Services/Instances/State/InstancePlayerCountTracker.cs

@@ -0,0 +1,140 @@
+using Phantom.Agent.Minecraft.Instance;
+using Phantom.Agent.Minecraft.Server;
+using Phantom.Agent.Rpc;
+using Phantom.Common.Data.Instance;
+using Phantom.Common.Messages.Agent.ToController;
+using Phantom.Utils.Logging;
+using Phantom.Utils.Tasks;
+using Phantom.Utils.Threading;
+
+namespace Phantom.Agent.Services.Instances.State;
+
+sealed class InstancePlayerCountTracker : CancellableBackgroundTask {
+	private readonly ControllerConnection controllerConnection;
+	private readonly Guid instanceGuid;
+	private readonly ushort serverPort;
+	private readonly InstanceProcess process;
+	
+	private readonly TaskCompletionSource firstDetection = AsyncTasks.CreateCompletionSource();
+	private readonly ManualResetEventSlim serverOutputEvent = new ();
+	
+	private InstancePlayerCounts? playerCounts;
+	
+	public InstancePlayerCounts? PlayerCounts {
+		get {
+			lock (this) {
+				return playerCounts;
+			}
+		}
+		private set {
+			EventHandler<int?>? onlinePlayerCountChanged;
+			lock (this) {
+				if (playerCounts == value) {
+					return;
+				}
+				
+				playerCounts = value;
+				onlinePlayerCountChanged = OnlinePlayerCountChanged;
+			}
+			
+			onlinePlayerCountChanged?.Invoke(this, value?.Online);
+			controllerConnection.Send(new ReportInstancePlayerCountsMessage(instanceGuid, value));
+		}
+	}
+	
+	private event EventHandler<int?>? OnlinePlayerCountChanged;
+	
+	private bool isDisposed = false;
+	
+	public InstancePlayerCountTracker(InstanceContext context, InstanceProcess process, ushort serverPort) : base(PhantomLogger.Create<InstancePlayerCountTracker>(context.ShortName)) {
+		this.controllerConnection = context.Services.ControllerConnection;
+		this.instanceGuid = context.InstanceGuid;
+		this.process = process;
+		this.serverPort = serverPort;
+		Start();
+	}
+	
+	protected override async Task RunTask() {
+		// Give the server time to start accepting connections.
+		await Task.Delay(TimeSpan.FromSeconds(10), CancellationToken);
+		
+		serverOutputEvent.Set();
+		process.AddOutputListener(OnOutput, maxLinesToReadFromHistory: 0);
+		
+		while (!CancellationToken.IsCancellationRequested) {
+			serverOutputEvent.Reset();
+			
+			PlayerCounts = await TryGetPlayerCounts();
+			
+			if (!firstDetection.Task.IsCompleted) {
+				firstDetection.SetResult();
+			}
+			
+			await Task.Delay(TimeSpan.FromSeconds(10), CancellationToken);
+			await serverOutputEvent.WaitHandle.WaitOneAsync(CancellationToken);
+			await Task.Delay(TimeSpan.FromSeconds(1), CancellationToken);
+		}
+	}
+	
+	private async Task<InstancePlayerCounts?> TryGetPlayerCounts() {
+		try {
+			var result = await ServerStatusProtocol.GetPlayerCounts(serverPort, CancellationToken);
+			Logger.Debug("Detected {OnlinePlayerCount} / {MaximumPlayerCount} online player(s).", result.Online, result.Maximum);
+			return result;
+		} catch (ServerStatusProtocol.ProtocolException e) {
+			Logger.Error(e.Message);
+			return null;
+		} catch (Exception e) {
+			Logger.Error(e, "Caught exception while checking online player count.");
+			return null;
+		}
+	}
+	
+	public async Task WaitForOnlinePlayers(CancellationToken cancellationToken) {
+		await firstDetection.Task.WaitAsync(cancellationToken);
+		
+		var onlinePlayersDetected = AsyncTasks.CreateCompletionSource();
+		
+		lock (this) {
+			if (playerCounts is { Online: > 0 }) {
+				return;
+			}
+			else if (playerCounts == null) {
+				throw new InvalidOperationException();
+			}
+			
+			OnlinePlayerCountChanged += OnOnlinePlayerCountChanged;
+			
+			void OnOnlinePlayerCountChanged(object? sender, int? newPlayerCount) {
+				if (newPlayerCount == null) {
+					onlinePlayersDetected.TrySetException(new InvalidOperationException());
+					OnlinePlayerCountChanged -= OnOnlinePlayerCountChanged;
+				}
+				else if (newPlayerCount > 0) {
+					onlinePlayersDetected.TrySetResult();
+					OnlinePlayerCountChanged -= OnOnlinePlayerCountChanged;
+				}
+			}
+		}
+		
+		await onlinePlayersDetected.Task;
+	}
+	
+	private void OnOutput(object? sender, string? line) {
+		lock (this) {
+			if (!isDisposed) {
+				serverOutputEvent.Set();
+			}
+		}
+	}
+	
+	protected override void Dispose() {
+		lock (this) {
+			isDisposed = true;
+			playerCounts = null;
+		}
+		
+		process.RemoveOutputListener(OnOutput);
+		serverOutputEvent.Dispose();
+	}
+}

Agent/Phantom.Agent.Services/Instances/State/InstanceRunningState.cs

@@ -19,6 +19,7 @@ sealed class InstanceRunningState : IDisposable {
 	private readonly CancellationToken cancellationToken;
 	
 	private readonly InstanceLogSender logSender;
+	private readonly InstancePlayerCountTracker playerCountTracker;
 	private readonly BackupScheduler backupScheduler;
 	
 	private bool isDisposed;
@@ -32,8 +33,9 @@ sealed class InstanceRunningState : IDisposable {
 		this.cancellationToken = cancellationToken;
 		
 		this.logSender = new InstanceLogSender(context.Services.ControllerConnection, context.InstanceGuid, context.ShortName);
+		this.playerCountTracker = new InstancePlayerCountTracker(context, process, configuration.ServerPort);
 		
-		this.backupScheduler = new BackupScheduler(context, process, configuration.ServerPort);
+		this.backupScheduler = new BackupScheduler(context, playerCountTracker);
 		this.backupScheduler.BackupCompleted += OnScheduledBackupCompleted;
 	}
 	
@@ -93,6 +95,11 @@ sealed class InstanceRunningState : IDisposable {
 		}
 	}
 	
+	public void OnStopInitiated() {
+		backupScheduler.Stop();
+		playerCountTracker.Stop();
+	}
+	
 	private bool TryDispose() {
 		lock (this) {
 			if (isDisposed) {
@@ -102,8 +109,8 @@ sealed class InstanceRunningState : IDisposable {
 			isDisposed = true;
 		}
 		
+		OnStopInitiated();
 		logSender.Stop();
-		backupScheduler.Stop();
 		
 		Process.Dispose();
 		

Agent/Phantom.Agent.Services/Instances/State/InstanceStopProcedure.cs

@@ -25,6 +25,8 @@ static class InstanceStopProcedure {
 		
 		try {
 			// Too late to cancel the stop procedure now.
+			runningState.OnStopInitiated();
+			
 			if (!process.HasEnded) {
 				context.Logger.Information("Session stopping now.");
 				await DoStop(context, process);
@@ -85,7 +87,7 @@ static class InstanceStopProcedure {
 	private static async Task WaitForSessionToEnd(InstanceContext context, InstanceProcess process) {
 		try {
 			await process.WaitForExit(TimeSpan.FromSeconds(55));
-		} catch (OperationCanceledException) {
+		} catch (TimeoutException) {
 			try {
 				context.Logger.Warning("Waiting timed out, killing session...");
 				process.Kill();

Agent/Phantom.Agent.Services/Rpc/ControllerMessageHandlerActor.cs

@@ -1,4 +1,5 @@
 using Phantom.Agent.Services.Instances;
+using Phantom.Common.Data;
 using Phantom.Common.Data.Instance;
 using Phantom.Common.Data.Replies;
 using Phantom.Common.Messages.Agent;
@@ -32,10 +33,10 @@ public sealed class ControllerMessageHandlerActor : ReceiveActor<IMessageToAgent
 		
 		ReceiveAsync<RegisterAgentSuccessMessage>(HandleRegisterAgentSuccess);
 		Receive<RegisterAgentFailureMessage>(HandleRegisterAgentFailure);
-		ReceiveAndReplyLater<ConfigureInstanceMessage, InstanceActionResult<ConfigureInstanceResult>>(HandleConfigureInstance);
+		ReceiveAndReplyLater<ConfigureInstanceMessage, Result<ConfigureInstanceResult, InstanceActionFailure>>(HandleConfigureInstance);
-		ReceiveAndReplyLater<LaunchInstanceMessage, InstanceActionResult<LaunchInstanceResult>>(HandleLaunchInstance);
+		ReceiveAndReplyLater<LaunchInstanceMessage, Result<LaunchInstanceResult, InstanceActionFailure>>(HandleLaunchInstance);
-		ReceiveAndReplyLater<StopInstanceMessage, InstanceActionResult<StopInstanceResult>>(HandleStopInstance);
+		ReceiveAndReplyLater<StopInstanceMessage, Result<StopInstanceResult, InstanceActionFailure>>(HandleStopInstance);
-		ReceiveAndReplyLater<SendCommandToInstanceMessage, InstanceActionResult<SendCommandToInstanceResult>>(HandleSendCommandToInstance);
+		ReceiveAndReplyLater<SendCommandToInstanceMessage, Result<SendCommandToInstanceResult, InstanceActionFailure>>(HandleSendCommandToInstance);
 		Receive<ReplyMessage>(HandleReply);
 	}
 	
@@ -74,23 +75,23 @@ public sealed class ControllerMessageHandlerActor : ReceiveActor<IMessageToAgent
 		Environment.Exit(1);
 	}
 	
-	private Task<InstanceActionResult<ConfigureInstanceResult>> HandleConfigureInstance(ConfigureInstanceMessage message, bool alwaysReportStatus) {
+	private Task<Result<ConfigureInstanceResult, InstanceActionFailure>> HandleConfigureInstance(ConfigureInstanceMessage message, bool alwaysReportStatus) {
 		return agent.InstanceManager.Request(new InstanceManagerActor.ConfigureInstanceCommand(message.InstanceGuid, message.Configuration, message.LaunchProperties, message.LaunchNow, alwaysReportStatus));
 	}
 	
-	private async Task<InstanceActionResult<ConfigureInstanceResult>> HandleConfigureInstance(ConfigureInstanceMessage message) {
+	private async Task<Result<ConfigureInstanceResult, InstanceActionFailure>> HandleConfigureInstance(ConfigureInstanceMessage message) {
 		return await HandleConfigureInstance(message, alwaysReportStatus: false);
 	}
 	
-	private async Task<InstanceActionResult<LaunchInstanceResult>> HandleLaunchInstance(LaunchInstanceMessage message) {
+	private async Task<Result<LaunchInstanceResult, InstanceActionFailure>> HandleLaunchInstance(LaunchInstanceMessage message) {
 		return await agent.InstanceManager.Request(new InstanceManagerActor.LaunchInstanceCommand(message.InstanceGuid));
 	}
 	
-	private async Task<InstanceActionResult<StopInstanceResult>> HandleStopInstance(StopInstanceMessage message) {
+	private async Task<Result<StopInstanceResult, InstanceActionFailure>> HandleStopInstance(StopInstanceMessage message) {
 		return await agent.InstanceManager.Request(new InstanceManagerActor.StopInstanceCommand(message.InstanceGuid, message.StopStrategy));
 	}
 	
-	private async Task<InstanceActionResult<SendCommandToInstanceResult>> HandleSendCommandToInstance(SendCommandToInstanceMessage message) {
+	private async Task<Result<SendCommandToInstanceResult, InstanceActionFailure>> HandleSendCommandToInstance(SendCommandToInstanceMessage message) {
 		return await agent.InstanceManager.Request(new InstanceManagerActor.SendCommandToInstanceCommand(message.InstanceGuid, message.Command));
 	}
 	

Common/Phantom.Common.Data.Web/Instance/Instance.cs

@@ -8,9 +8,10 @@ public sealed partial record Instance(
 	[property: MemoryPackOrder(0)] Guid InstanceGuid,
 	[property: MemoryPackOrder(1)] InstanceConfiguration Configuration,
 	[property: MemoryPackOrder(2)] IInstanceStatus Status,
-	[property: MemoryPackOrder(3)] bool LaunchAutomatically
+	[property: MemoryPackOrder(3)] InstancePlayerCounts? PlayerCounts,
+	[property: MemoryPackOrder(4)] bool LaunchAutomatically
 ) {
 	public static Instance Offline(Guid instanceGuid, InstanceConfiguration configuration, bool launchAutomatically = false) {
-		return new Instance(instanceGuid, configuration, InstanceStatus.Offline, launchAutomatically);
+		return new Instance(instanceGuid, configuration, InstanceStatus.Offline, PlayerCounts: null, launchAutomatically);
 	}
 }

Common/Phantom.Common.Data.Web/Users/AuthenticatedUserInfo.cs

@@ -0,0 +1,24 @@
+using System.Collections.Immutable;
+using MemoryPack;
+
+namespace Phantom.Common.Data.Web.Users;
+
+[MemoryPackable(GenerateType.VersionTolerant)]
+public sealed partial record AuthenticatedUserInfo(
+	[property: MemoryPackOrder(0)] Guid Guid,
+	[property: MemoryPackOrder(1)] string Name,
+	[property: MemoryPackOrder(2)] PermissionSet Permissions,
+	[property: MemoryPackOrder(3)] ImmutableHashSet<Guid> ManagedAgentGuids
+) {
+	public bool CheckPermission(Permission permission) {
+		return Permissions.Check(permission);
+	}
+	
+	public bool HasAccessToAgent(Guid agentGuid) {
+		return ManagedAgentGuids.Contains(agentGuid) || Permissions.Check(Permission.ManageAllAgents);
+	}
+	
+	public ImmutableHashSet<Guid> FilterAccessibleAgentGuids(ImmutableHashSet<Guid> agentGuids) {
+		return Permissions.Check(Permission.ManageAllAgents) ? agentGuids : agentGuids.Intersect(ManagedAgentGuids);
+	}
+}

Common/Phantom.Common.Data.Web/Users/LogInSuccess.cs

@@ -5,7 +5,6 @@ namespace Phantom.Common.Data.Web.Users;
 
 [MemoryPackable(GenerateType.VersionTolerant)]
 public sealed partial record LogInSuccess(
-	[property: MemoryPackOrder(0)] Guid UserGuid,
+	[property: MemoryPackOrder(0)] AuthenticatedUserInfo UserInfo,
-	[property: MemoryPackOrder(1)] PermissionSet Permissions,
+	[property: MemoryPackOrder(1)] ImmutableArray<byte> AuthToken
-	[property: MemoryPackOrder(2)] ImmutableArray<byte> Token
 );

Common/Phantom.Common.Data.Web/Users/Permission.cs

@@ -14,6 +14,9 @@ public sealed record Permission(string Id, Permission? Parent) {
 		return Register(id, this);
 	}
 	
+	public const string ManageAllAgentsPolicy = "Agents.ManageAll";
+	public static readonly Permission ManageAllAgents = Register(ManageAllAgentsPolicy);
+	
 	public const string ViewInstancesPolicy = "Instances.View";
 	public static readonly Permission ViewInstances = Register(ViewInstancesPolicy);
 	

Common/Phantom.Common.Data.Web/Users/UserActionFailure.cs

@@ -0,0 +1,5 @@
+namespace Phantom.Common.Data.Web.Users;
+
+public enum UserActionFailure {
+	NotAuthorized
+}

Common/Phantom.Common.Data.Web/Users/UserInstanceActionFailure.cs

@@ -0,0 +1,25 @@
+using MemoryPack;
+using Phantom.Common.Data.Replies;
+
+namespace Phantom.Common.Data.Web.Users;
+
+[MemoryPackable]
+[MemoryPackUnion(0, typeof(OfUserActionFailure))]
+[MemoryPackUnion(1, typeof(OfInstanceActionFailure))]
+public abstract partial record UserInstanceActionFailure {
+	internal UserInstanceActionFailure() {}
+	
+	public static implicit operator UserInstanceActionFailure(UserActionFailure failure) {
+		return new OfUserActionFailure(failure);
+	}
+	
+	public static implicit operator UserInstanceActionFailure(InstanceActionFailure failure) {
+		return new OfInstanceActionFailure(failure);
+	}
+}
+
+[MemoryPackable(GenerateType.VersionTolerant)]
+public sealed partial record OfUserActionFailure([property: MemoryPackOrder(0)] UserActionFailure Failure) : UserInstanceActionFailure;
+
+[MemoryPackable(GenerateType.VersionTolerant)]
+public sealed partial record OfInstanceActionFailure([property: MemoryPackOrder(0)] InstanceActionFailure Failure) : UserInstanceActionFailure;

Common/Phantom.Common.Data/Backups/BackupCreationResultKind.cs

@@ -1,15 +1,16 @@
 namespace Phantom.Common.Data.Backups;
 
 public enum BackupCreationResultKind : byte {
-	UnknownError,
+	UnknownError = 0,
-	Success,
+	Success = 1,
-	InstanceNotRunning,
+	InstanceNotRunning = 2,
-	BackupCancelled,
+	BackupTimedOut = 3,
-	BackupAlreadyRunning,
+	BackupCancelled = 4,
-	BackupFileAlreadyExists,
+	BackupAlreadyRunning = 5,
-	CouldNotCreateBackupFolder,
+	BackupFileAlreadyExists = 6,
-	CouldNotCopyWorldToTemporaryFolder,
+	CouldNotCreateBackupFolder = 7,
-	CouldNotCreateWorldArchive
+	CouldNotCopyWorldToTemporaryFolder = 8,
+	CouldNotCreateWorldArchive = 9
 }
 
 public static class BackupCreationResultSummaryExtensions {

Common/Phantom.Common.Data/Instance/IInstanceStatus.cs

@@ -9,9 +9,10 @@ namespace Phantom.Common.Data.Instance;
 [MemoryPackUnion(3, typeof(InstanceIsDownloading))]
 [MemoryPackUnion(4, typeof(InstanceIsLaunching))]
 [MemoryPackUnion(5, typeof(InstanceIsRunning))]
-[MemoryPackUnion(6, typeof(InstanceIsRestarting))]
+[MemoryPackUnion(6, typeof(InstanceIsBackingUp))]
-[MemoryPackUnion(7, typeof(InstanceIsStopping))]
+[MemoryPackUnion(7, typeof(InstanceIsRestarting))]
-[MemoryPackUnion(8, typeof(InstanceIsFailed))]
+[MemoryPackUnion(8, typeof(InstanceIsStopping))]
+[MemoryPackUnion(9, typeof(InstanceIsFailed))]
 public partial interface IInstanceStatus {}
 
 [MemoryPackable(GenerateType.VersionTolerant)]
@@ -32,6 +33,9 @@ public sealed partial record InstanceIsLaunching : IInstanceStatus;
 [MemoryPackable(GenerateType.VersionTolerant)]
 public sealed partial record InstanceIsRunning : IInstanceStatus;
 
+[MemoryPackable(GenerateType.VersionTolerant)]
+public sealed partial record InstanceIsBackingUp : IInstanceStatus;
+
 [MemoryPackable(GenerateType.VersionTolerant)]
 public sealed partial record InstanceIsRestarting : IInstanceStatus;
 
@@ -46,6 +50,7 @@ public static class InstanceStatus {
 	public static readonly IInstanceStatus NotRunning = new InstanceIsNotRunning();
 	public static readonly IInstanceStatus Launching = new InstanceIsLaunching();
 	public static readonly IInstanceStatus Running = new InstanceIsRunning();
+	public static readonly IInstanceStatus BackingUp = new InstanceIsBackingUp();
 	public static readonly IInstanceStatus Restarting = new InstanceIsRestarting();
 	public static readonly IInstanceStatus Stopping = new InstanceIsStopping();
 	
@@ -58,7 +63,7 @@ public static class InstanceStatus {
 	}
 	
 	public static bool IsRunning(this IInstanceStatus status) {
-		return status is InstanceIsRunning;
+		return status is InstanceIsRunning or InstanceIsBackingUp;
 	}
 	
 	public static bool IsStopping(this IInstanceStatus status) {
@@ -70,10 +75,10 @@ public static class InstanceStatus {
 	}
 	
 	public static bool CanStop(this IInstanceStatus status) {
-		return status is InstanceIsDownloading or InstanceIsLaunching or InstanceIsRunning;
+		return status.IsRunning() || status.IsLaunching();
 	}
 	
 	public static bool CanSendCommand(this IInstanceStatus status) {
-		return status is InstanceIsRunning;
+		return status.IsRunning();
 	}
 }

Common/Phantom.Common.Data/Instance/InstancePlayerCounts.cs

@@ -0,0 +1,9 @@
+using MemoryPack;
+
+namespace Phantom.Common.Data.Instance;
+
+[MemoryPackable(GenerateType.VersionTolerant)]
+public readonly partial record struct InstancePlayerCounts(
+	[property: MemoryPackOrder(0)] int Online,
+	[property: MemoryPackOrder(1)] int Maximum
+);

Common/Phantom.Common.Data/Optional.cs

@@ -0,0 +1,10 @@
+using MemoryPack;
+
+namespace Phantom.Common.Data;
+
+[MemoryPackable]
+public readonly partial record struct Optional<T>(T? Value) {
+	public static implicit operator Optional<T>(T? value) {
+		return new Optional<T>(value);
+	}
+}

Common/Phantom.Common.Data/Replies/InstanceActionFailure.cs

@@ -0,0 +1,20 @@
+namespace Phantom.Common.Data.Replies;
+
+public enum InstanceActionFailure : byte {
+	AgentDoesNotExist,
+	AgentShuttingDown,
+	AgentIsNotResponding,
+	InstanceDoesNotExist
+}
+
+public static class InstanceActionFailureExtensions {
+	public static string ToSentence(this InstanceActionFailure failure) {
+		return failure switch {
+			InstanceActionFailure.AgentDoesNotExist    => "Agent does not exist.",
+			InstanceActionFailure.AgentShuttingDown    => "Agent is shutting down.",
+			InstanceActionFailure.AgentIsNotResponding => "Agent is not responding.",
+			InstanceActionFailure.InstanceDoesNotExist => "Instance does not exist.",
+			_                                          => "Unknown error."
+		};
+	}
+}

Common/Phantom.Common.Data/Replies/InstanceActionGeneralResult.cs

@@ -1,9 +0,0 @@
-namespace Phantom.Common.Data.Replies;
-
-public enum InstanceActionGeneralResult : byte {
-	None,
-	AgentDoesNotExist,
-	AgentShuttingDown,
-	AgentIsNotResponding,
-	InstanceDoesNotExist
-}

Common/Phantom.Common.Data/Replies/InstanceActionResult.cs

@@ -1,42 +0,0 @@
-using MemoryPack;
-
-namespace Phantom.Common.Data.Replies;
-
-[MemoryPackable(GenerateType.VersionTolerant)]
-public sealed partial record InstanceActionResult<T>(
-	[property: MemoryPackOrder(0)] InstanceActionGeneralResult GeneralResult,
-	[property: MemoryPackOrder(1)] T? ConcreteResult
-) {
-	public bool Is(T? concreteResult) {
-		return GeneralResult == InstanceActionGeneralResult.None && EqualityComparer<T>.Default.Equals(ConcreteResult, concreteResult);
-	}
-
-	public InstanceActionResult<T2> Map<T2>(Func<T, T2> mapper) {
-		return new InstanceActionResult<T2>(GeneralResult, ConcreteResult is not null ? mapper(ConcreteResult) : default);
-	}
-
-	public string ToSentence(Func<T, string> concreteResultToSentence) {
-		return GeneralResult switch {
-			InstanceActionGeneralResult.None                 => concreteResultToSentence(ConcreteResult!),
-			InstanceActionGeneralResult.AgentDoesNotExist    => "Agent does not exist.",
-			InstanceActionGeneralResult.AgentShuttingDown    => "Agent is shutting down.",
-			InstanceActionGeneralResult.AgentIsNotResponding => "Agent is not responding.",
-			InstanceActionGeneralResult.InstanceDoesNotExist => "Instance does not exist.",
-			_                                                => "Unknown result."
-		};
-	}
-}
-
-public static class InstanceActionResult {
-	public static InstanceActionResult<T> General<T>(InstanceActionGeneralResult generalResult) {
-		return new InstanceActionResult<T>(generalResult, default);
-	}
-
-	public static InstanceActionResult<T> Concrete<T>(T? concreteResult) {
-		return new InstanceActionResult<T>(InstanceActionGeneralResult.None, concreteResult);
-	}
-
-	public static InstanceActionResult<T> DidNotReplyIfNull<T>(this InstanceActionResult<T>? result) {
-		return result ?? General<T>(InstanceActionGeneralResult.AgentIsNotResponding);
-	}
-}

Common/Phantom.Common.Data/Result.cs

@@ -0,0 +1,108 @@
+using System.Diagnostics.CodeAnalysis;
+using MemoryPack;
+using Phantom.Utils.Result;
+
+namespace Phantom.Common.Data;
+
+[MemoryPackable(GenerateType.VersionTolerant)]
+public sealed partial class Result<TValue, TError> {
+	[MemoryPackOrder(0)]
+	[MemoryPackInclude]
+	private readonly bool hasValue;
+	
+	[MemoryPackOrder(1)]
+	[MemoryPackInclude]
+	private readonly TValue? value;
+	
+	[MemoryPackOrder(2)]
+	[MemoryPackInclude]
+	private readonly TError? error;
+	
+	[MemoryPackIgnore]
+	public TValue Value => hasValue ? value! : throw new InvalidOperationException("Attempted to get value from an error result.");
+	
+	[MemoryPackIgnore]
+	public TError Error => !hasValue ? error! : throw new InvalidOperationException("Attempted to get error from a success result.");
+	
+	private Result(bool hasValue, TValue? value, TError? error) {
+		this.hasValue = hasValue;
+		this.value = value;
+		this.error = error;
+	}
+	
+	public bool Is(TValue expectedValue) {
+		return hasValue && EqualityComparer<TValue>.Default.Equals(value, expectedValue);
+	}
+	
+	public TOutput Into<TOutput>(Func<TValue, TOutput> valueConverter, Func<TError, TOutput> errorConverter) {
+		return hasValue ? valueConverter(value!) : errorConverter(error!);
+	}
+	
+	public Result<TValue, TNewError> MapError<TNewError>(Func<TError, TNewError> errorConverter) {
+		return hasValue ? value! : errorConverter(error!);
+	}
+	
+	public Utils.Result.Result Variant() {
+		return hasValue ? new Ok<TValue>(Value) : new Err<TError>(Error);
+	}
+	
+	public static implicit operator Result<TValue, TError>(TValue value) {
+		return new Result<TValue, TError>(hasValue: true, value, default);
+	}
+	
+	public static implicit operator Result<TValue, TError>(TError error) {
+		return new Result<TValue, TError>(hasValue: false, default, error);
+	}
+	
+	public static implicit operator bool(Result<TValue, TError> result) {
+		return result.hasValue;
+	}
+}
+
+[MemoryPackable(GenerateType.VersionTolerant)]
+public sealed partial class Result<TError> {
+	[MemoryPackOrder(0)]
+	[MemoryPackInclude]
+	private readonly bool hasValue;
+	
+	[MemoryPackOrder(1)]
+	[MemoryPackInclude]
+	private readonly TError? error;
+	
+	[MemoryPackIgnore]
+	public TError Error => !hasValue ? error! : throw new InvalidOperationException("Attempted to get error from a success result.");
+	
+	private Result(bool hasValue, TError? error) {
+		this.hasValue = hasValue;
+		this.error = error;
+	}
+	
+	public bool TryGetError([MaybeNullWhen(false)] out TError error) {
+		if (hasValue) {
+			error = default;
+			return false;
+		}
+		else {
+			error = this.error!;
+			return true;
+		}
+	}
+	
+	public static implicit operator Result<TError>([SuppressMessage("ReSharper", "UnusedParameter.Global")] Result.OkType _) {
+		return new Result<TError>(hasValue: true, default);
+	}
+	
+	public static implicit operator Result<TError>(TError error) {
+		return new Result<TError>(hasValue: false, error);
+	}
+	
+	public static implicit operator bool(Result<TError> result) {
+		return result.hasValue;
+	}
+}
+
+public static class Result {
+	public static OkType Ok { get; }  = new ();
+	
+	public readonly record struct OkType;
+}

Common/Phantom.Common.Messages.Agent/AgentMessageRegistries.cs

@@ -1,4 +1,5 @@
-using Phantom.Common.Data.Replies;
+using Phantom.Common.Data;
+using Phantom.Common.Data.Replies;
 using Phantom.Common.Messages.Agent.BiDirectional;
 using Phantom.Common.Messages.Agent.ToAgent;
 using Phantom.Common.Messages.Agent.ToController;
@@ -16,10 +17,10 @@ public static class AgentMessageRegistries {
 	static AgentMessageRegistries() {
 		ToAgent.Add<RegisterAgentSuccessMessage>(0);
 		ToAgent.Add<RegisterAgentFailureMessage>(1);
-		ToAgent.Add<ConfigureInstanceMessage, InstanceActionResult<ConfigureInstanceResult>>(2);
+		ToAgent.Add<ConfigureInstanceMessage, Result<ConfigureInstanceResult, InstanceActionFailure>>(2);
-		ToAgent.Add<LaunchInstanceMessage, InstanceActionResult<LaunchInstanceResult>>(3);
+		ToAgent.Add<LaunchInstanceMessage, Result<LaunchInstanceResult, InstanceActionFailure>>(3);
-		ToAgent.Add<StopInstanceMessage, InstanceActionResult<StopInstanceResult>>(4);
+		ToAgent.Add<StopInstanceMessage, Result<StopInstanceResult, InstanceActionFailure>>(4);
-		ToAgent.Add<SendCommandToInstanceMessage, InstanceActionResult<SendCommandToInstanceResult>>(5);
+		ToAgent.Add<SendCommandToInstanceMessage, Result<SendCommandToInstanceResult, InstanceActionFailure>>(5);
 		ToAgent.Add<ReplyMessage>(127);
 		
 		ToController.Add<RegisterAgentMessage>(0);
@@ -30,6 +31,7 @@ public static class AgentMessageRegistries {
 		ToController.Add<InstanceOutputMessage>(5);
 		ToController.Add<ReportAgentStatusMessage>(6);
 		ToController.Add<ReportInstanceEventMessage>(7);
+		ToController.Add<ReportInstancePlayerCountsMessage>(8);
 		ToController.Add<ReplyMessage>(127);
 	}
 	

Common/Phantom.Common.Messages.Agent/ToAgent/ConfigureInstanceMessage.cs

@@ -1,4 +1,5 @@
 using MemoryPack;
+using Phantom.Common.Data;
 using Phantom.Common.Data.Instance;
 using Phantom.Common.Data.Replies;
 using Phantom.Utils.Actor;
@@ -11,4 +12,4 @@ public sealed partial record ConfigureInstanceMessage(
 	[property: MemoryPackOrder(1)] InstanceConfiguration Configuration,
 	[property: MemoryPackOrder(2)] InstanceLaunchProperties LaunchProperties,
 	[property: MemoryPackOrder(3)] bool LaunchNow = false
-) : IMessageToAgent, ICanReply<InstanceActionResult<ConfigureInstanceResult>>;
+) : IMessageToAgent, ICanReply<Result<ConfigureInstanceResult, InstanceActionFailure>>;

Common/Phantom.Common.Messages.Agent/ToAgent/LaunchInstanceMessage.cs

@@ -1,4 +1,5 @@
 using MemoryPack;
+using Phantom.Common.Data;
 using Phantom.Common.Data.Replies;
 using Phantom.Utils.Actor;
 
@@ -7,4 +8,4 @@ namespace Phantom.Common.Messages.Agent.ToAgent;
 [MemoryPackable(GenerateType.VersionTolerant)]
 public sealed partial record LaunchInstanceMessage(
 	[property: MemoryPackOrder(0)] Guid InstanceGuid
-) : IMessageToAgent, ICanReply<InstanceActionResult<LaunchInstanceResult>>;
+) : IMessageToAgent, ICanReply<Result<LaunchInstanceResult, InstanceActionFailure>>;

Common/Phantom.Common.Messages.Agent/ToAgent/SendCommandToInstanceMessage.cs

@@ -1,4 +1,5 @@
 using MemoryPack;
+using Phantom.Common.Data;
 using Phantom.Common.Data.Replies;
 using Phantom.Utils.Actor;
 
@@ -8,4 +9,4 @@ namespace Phantom.Common.Messages.Agent.ToAgent;
 public sealed partial record SendCommandToInstanceMessage(
 	[property: MemoryPackOrder(0)] Guid InstanceGuid,
 	[property: MemoryPackOrder(1)] string Command
-) : IMessageToAgent, ICanReply<InstanceActionResult<SendCommandToInstanceResult>>;
+) : IMessageToAgent, ICanReply<Result<SendCommandToInstanceResult, InstanceActionFailure>>;

Common/Phantom.Common.Messages.Agent/ToAgent/StopInstanceMessage.cs

@@ -1,4 +1,5 @@
 using MemoryPack;
+using Phantom.Common.Data;
 using Phantom.Common.Data.Minecraft;
 using Phantom.Common.Data.Replies;
 using Phantom.Utils.Actor;
@@ -9,4 +10,4 @@ namespace Phantom.Common.Messages.Agent.ToAgent;
 public sealed partial record StopInstanceMessage(
 	[property: MemoryPackOrder(0)] Guid InstanceGuid,
 	[property: MemoryPackOrder(1)] MinecraftStopStrategy StopStrategy
-) : IMessageToAgent, ICanReply<InstanceActionResult<StopInstanceResult>>;
+) : IMessageToAgent, ICanReply<Result<StopInstanceResult, InstanceActionFailure>>;

Common/Phantom.Common.Messages.Agent/ToController/ReportInstancePlayerCountsMessage.cs

@@ -0,0 +1,10 @@
+using MemoryPack;
+using Phantom.Common.Data.Instance;
+
+namespace Phantom.Common.Messages.Agent.ToController;
+
+[MemoryPackable(GenerateType.VersionTolerant)]
+public sealed partial record ReportInstancePlayerCountsMessage(
+	[property: MemoryPackOrder(0)] Guid InstanceGuid,
+	[property: MemoryPackOrder(1)] InstancePlayerCounts? PlayerCounts
+) : IMessageToController;

Common/Phantom.Common.Messages.Web/ToController/ChangeUserRolesMessage.cs

@@ -1,5 +1,6 @@
 using System.Collections.Immutable;
 using MemoryPack;
+using Phantom.Common.Data;
 using Phantom.Common.Data.Web.Users;
 using Phantom.Utils.Actor;
 
@@ -7,8 +8,8 @@ namespace Phantom.Common.Messages.Web.ToController;
 
 [MemoryPackable(GenerateType.VersionTolerant)]
 public sealed partial record ChangeUserRolesMessage(
-	[property: MemoryPackOrder(0)] Guid LoggedInUserGuid,
+	[property: MemoryPackOrder(0)] ImmutableArray<byte> AuthToken,
 	[property: MemoryPackOrder(1)] Guid SubjectUserGuid,
 	[property: MemoryPackOrder(2)] ImmutableHashSet<Guid> AddToRoleGuids,
 	[property: MemoryPackOrder(3)] ImmutableHashSet<Guid> RemoveFromRoleGuids
-) : IMessageToController, ICanReply<ChangeUserRolesResult>;
+) : IMessageToController, ICanReply<Result<ChangeUserRolesResult, UserActionFailure>>;

Common/Phantom.Common.Messages.Web/ToController/CreateOrUpdateInstanceMessage.cs

@@ -1,14 +1,16 @@
-using MemoryPack;
+using System.Collections.Immutable;
+using MemoryPack;
+using Phantom.Common.Data;
 using Phantom.Common.Data.Instance;
-using Phantom.Common.Data.Replies;
 using Phantom.Common.Data.Web.Instance;
+using Phantom.Common.Data.Web.Users;
 using Phantom.Utils.Actor;
 
 namespace Phantom.Common.Messages.Web.ToController;
 
 [MemoryPackable(GenerateType.VersionTolerant)]
 public sealed partial record CreateOrUpdateInstanceMessage(
-	[property: MemoryPackOrder(0)] Guid LoggedInUserGuid,
+	[property: MemoryPackOrder(0)] ImmutableArray<byte> AuthToken,
 	[property: MemoryPackOrder(1)] Guid InstanceGuid,
 	[property: MemoryPackOrder(2)] InstanceConfiguration Configuration
-) : IMessageToController, ICanReply<InstanceActionResult<CreateOrUpdateInstanceResult>>;
+) : IMessageToController, ICanReply<Result<CreateOrUpdateInstanceResult, UserInstanceActionFailure>>;

Common/Phantom.Common.Messages.Web/ToController/CreateUserMessage.cs

@@ -1,4 +1,6 @@
-using MemoryPack;
+using System.Collections.Immutable;
+using MemoryPack;
+using Phantom.Common.Data;
 using Phantom.Common.Data.Web.Users;
 using Phantom.Utils.Actor;
 
@@ -6,7 +8,7 @@ namespace Phantom.Common.Messages.Web.ToController;
 
 [MemoryPackable(GenerateType.VersionTolerant)]
 public sealed partial record CreateUserMessage(
-	[property: MemoryPackOrder(0)] Guid LoggedInUserGuid,
+	[property: MemoryPackOrder(0)] ImmutableArray<byte> AuthToken,
 	[property: MemoryPackOrder(1)] string Username,
 	[property: MemoryPackOrder(2)] string Password
-) : IMessageToController, ICanReply<CreateUserResult>;
+) : IMessageToController, ICanReply<Result<CreateUserResult, UserActionFailure>>;

Common/Phantom.Common.Messages.Web/ToController/DeleteUserMessage.cs

@@ -1,4 +1,6 @@
-using MemoryPack;
+using System.Collections.Immutable;
+using MemoryPack;
+using Phantom.Common.Data;
 using Phantom.Common.Data.Web.Users;
 using Phantom.Utils.Actor;
 
@@ -6,6 +8,6 @@ namespace Phantom.Common.Messages.Web.ToController;
 
 [MemoryPackable(GenerateType.VersionTolerant)]
 public sealed partial record DeleteUserMessage(
-	[property: MemoryPackOrder(0)] Guid LoggedInUserGuid,
+	[property: MemoryPackOrder(0)] ImmutableArray<byte> AuthToken,
 	[property: MemoryPackOrder(1)] Guid SubjectUserGuid
-) : IMessageToController, ICanReply<DeleteUserResult>;
+) : IMessageToController, ICanReply<Result<DeleteUserResult, UserActionFailure>>;

Common/Phantom.Common.Messages.Web/ToController/GetAuditLogMessage.cs

@@ -1,11 +1,14 @@
 using System.Collections.Immutable;
 using MemoryPack;
+using Phantom.Common.Data;
 using Phantom.Common.Data.Web.AuditLog;
+using Phantom.Common.Data.Web.Users;
 using Phantom.Utils.Actor;
 
 namespace Phantom.Common.Messages.Web.ToController;
 
 [MemoryPackable(GenerateType.VersionTolerant)]
 public sealed partial record GetAuditLogMessage(
-	[property: MemoryPackOrder(0)] int Count
+	[property: MemoryPackOrder(0)] ImmutableArray<byte> AuthToken,
-) : IMessageToController, ICanReply<ImmutableArray<AuditLogItem>>;
+	[property: MemoryPackOrder(1)] int Count
+) : IMessageToController, ICanReply<Result<ImmutableArray<AuditLogItem>, UserActionFailure>>;

Common/Phantom.Common.Messages.Web/ToController/GetAuthenticatedUser.cs

@@ -0,0 +1,13 @@
+using System.Collections.Immutable;
+using MemoryPack;
+using Phantom.Common.Data;
+using Phantom.Common.Data.Web.Users;
+using Phantom.Utils.Actor;
+
+namespace Phantom.Common.Messages.Web.ToController;
+
+[MemoryPackable(GenerateType.VersionTolerant)]
+public sealed partial record GetAuthenticatedUser(
+	[property: MemoryPackOrder(0)] Guid UserGuid,
+	[property: MemoryPackOrder(1)] ImmutableArray<byte> AuthToken
+) : IMessageToController, ICanReply<Optional<AuthenticatedUserInfo>>;

Common/Phantom.Common.Messages.Web/ToController/GetEventLogMessage.cs

@@ -1,11 +1,14 @@
 using System.Collections.Immutable;
 using MemoryPack;
+using Phantom.Common.Data;
 using Phantom.Common.Data.Web.EventLog;
+using Phantom.Common.Data.Web.Users;
 using Phantom.Utils.Actor;
 
 namespace Phantom.Common.Messages.Web.ToController;
 
 [MemoryPackable(GenerateType.VersionTolerant)]
 public sealed partial record GetEventLogMessage(
-	[property: MemoryPackOrder(0)] int Count
+	[property: MemoryPackOrder(0)] ImmutableArray<byte> AuthToken,
-) : IMessageToController, ICanReply<ImmutableArray<EventLogItem>>;
+	[property: MemoryPackOrder(1)] int Count
+) : IMessageToController, ICanReply<Result<ImmutableArray<EventLogItem>, UserActionFailure>>;

Common/Phantom.Common.Messages.Web/ToController/LaunchInstanceMessage.cs

@@ -1,12 +1,15 @@
-using MemoryPack;
+using System.Collections.Immutable;
+using MemoryPack;
+using Phantom.Common.Data;
 using Phantom.Common.Data.Replies;
+using Phantom.Common.Data.Web.Users;
 using Phantom.Utils.Actor;
 
 namespace Phantom.Common.Messages.Web.ToController;
 
 [MemoryPackable(GenerateType.VersionTolerant)]
 public sealed partial record LaunchInstanceMessage(
-	[property: MemoryPackOrder(0)] Guid LoggedInUserGuid,
+	[property: MemoryPackOrder(0)] ImmutableArray<byte> AuthToken,
 	[property: MemoryPackOrder(1)] Guid AgentGuid,
 	[property: MemoryPackOrder(2)] Guid InstanceGuid
-) : IMessageToController, ICanReply<InstanceActionResult<LaunchInstanceResult>>;
+) : IMessageToController, ICanReply<Result<LaunchInstanceResult, UserInstanceActionFailure>>;

Common/Phantom.Common.Messages.Web/ToController/LogInMessage.cs

@@ -1,4 +1,5 @@
 using MemoryPack;
+using Phantom.Common.Data;
 using Phantom.Common.Data.Web.Users;
 using Phantom.Utils.Actor;
 
@@ -8,4 +9,4 @@ namespace Phantom.Common.Messages.Web.ToController;
 public sealed partial record LogInMessage(
 	[property: MemoryPackOrder(0)] string Username,
 	[property: MemoryPackOrder(1)] string Password
-) : IMessageToController, ICanReply<LogInSuccess?>;
+) : IMessageToController, ICanReply<Optional<LogInSuccess>>;

Common/Phantom.Common.Messages.Web/ToController/SendCommandToInstanceMessage.cs

@@ -1,13 +1,16 @@
-using MemoryPack;
+using System.Collections.Immutable;
+using MemoryPack;
+using Phantom.Common.Data;
 using Phantom.Common.Data.Replies;
+using Phantom.Common.Data.Web.Users;
 using Phantom.Utils.Actor;
 
 namespace Phantom.Common.Messages.Web.ToController;
 
 [MemoryPackable(GenerateType.VersionTolerant)]
 public sealed partial record SendCommandToInstanceMessage(
-	[property: MemoryPackOrder(0)] Guid LoggedInUserGuid,
+	[property: MemoryPackOrder(0)] ImmutableArray<byte> AuthToken,
 	[property: MemoryPackOrder(1)] Guid AgentGuid,
 	[property: MemoryPackOrder(2)] Guid InstanceGuid,
 	[property: MemoryPackOrder(3)] string Command
-) : IMessageToController, ICanReply<InstanceActionResult<SendCommandToInstanceResult>>;
+) : IMessageToController, ICanReply<Result<SendCommandToInstanceResult, UserInstanceActionFailure>>;

Common/Phantom.Common.Messages.Web/ToController/StopInstanceMessage.cs

@@ -1,14 +1,17 @@
-using MemoryPack;
+using System.Collections.Immutable;
+using MemoryPack;
+using Phantom.Common.Data;
 using Phantom.Common.Data.Minecraft;
 using Phantom.Common.Data.Replies;
+using Phantom.Common.Data.Web.Users;
 using Phantom.Utils.Actor;
 
 namespace Phantom.Common.Messages.Web.ToController;
 
 [MemoryPackable(GenerateType.VersionTolerant)]
 public sealed partial record StopInstanceMessage(
-	[property: MemoryPackOrder(0)] Guid LoggedInUserGuid,
+	[property: MemoryPackOrder(0)] ImmutableArray<byte> AuthToken,
 	[property: MemoryPackOrder(1)] Guid AgentGuid,
 	[property: MemoryPackOrder(2)] Guid InstanceGuid,
 	[property: MemoryPackOrder(3)] MinecraftStopStrategy StopStrategy
-) : IMessageToController, ICanReply<InstanceActionResult<StopInstanceResult>>;
+) : IMessageToController, ICanReply<Result<StopInstanceResult, UserInstanceActionFailure>>;

Common/Phantom.Common.Messages.Web/ToWeb/RefreshUserSessionMessage.cs

@@ -0,0 +1,8 @@
+using MemoryPack;
+
+namespace Phantom.Common.Messages.Web.ToWeb;
+
+[MemoryPackable(GenerateType.VersionTolerant)]
+public sealed partial record RefreshUserSessionMessage(
+	[property: MemoryPackOrder(0)] Guid UserGuid
+) : IMessageToWeb;

Common/Phantom.Common.Messages.Web/WebMessageRegistries.cs

@@ -1,4 +1,5 @@
 using System.Collections.Immutable;
+using Phantom.Common.Data;
 using Phantom.Common.Data.Java;
 using Phantom.Common.Data.Minecraft;
 using Phantom.Common.Data.Replies;
@@ -23,29 +24,31 @@ public static class WebMessageRegistries {
 	static WebMessageRegistries() {
 		ToController.Add<RegisterWebMessage>(0);
 		ToController.Add<UnregisterWebMessage>(1);
-		ToController.Add<LogInMessage, LogInSuccess?>(2);
+		ToController.Add<LogInMessage, Optional<LogInSuccess>>(2);
 		ToController.Add<LogOutMessage>(3);
-		ToController.Add<CreateOrUpdateAdministratorUserMessage, CreateOrUpdateAdministratorUserResult>(4);
+		ToController.Add<GetAuthenticatedUser, Optional<AuthenticatedUserInfo>>(4);
-		ToController.Add<CreateUserMessage, CreateUserResult>(5);
+		ToController.Add<CreateOrUpdateAdministratorUserMessage, CreateOrUpdateAdministratorUserResult>(5);
-		ToController.Add<DeleteUserMessage, DeleteUserResult>(6);
+		ToController.Add<CreateUserMessage, Result<CreateUserResult, UserActionFailure>>(6);
-		ToController.Add<GetUsersMessage, ImmutableArray<UserInfo>>(7);
+		ToController.Add<DeleteUserMessage, Result<DeleteUserResult, UserActionFailure>>(7);
-		ToController.Add<GetRolesMessage, ImmutableArray<RoleInfo>>(8);
+		ToController.Add<GetUsersMessage, ImmutableArray<UserInfo>>(8);
-		ToController.Add<GetUserRolesMessage, ImmutableDictionary<Guid, ImmutableArray<Guid>>>(9);
+		ToController.Add<GetRolesMessage, ImmutableArray<RoleInfo>>(9);
-		ToController.Add<ChangeUserRolesMessage, ChangeUserRolesResult>(10);
+		ToController.Add<GetUserRolesMessage, ImmutableDictionary<Guid, ImmutableArray<Guid>>>(10);
-		ToController.Add<CreateOrUpdateInstanceMessage, InstanceActionResult<CreateOrUpdateInstanceResult>>(11);
+		ToController.Add<ChangeUserRolesMessage, Result<ChangeUserRolesResult, UserActionFailure>>(11);
-		ToController.Add<LaunchInstanceMessage, InstanceActionResult<LaunchInstanceResult>>(12);
+		ToController.Add<CreateOrUpdateInstanceMessage, Result<CreateOrUpdateInstanceResult, UserInstanceActionFailure>>(12);
-		ToController.Add<StopInstanceMessage, InstanceActionResult<StopInstanceResult>>(13);
+		ToController.Add<LaunchInstanceMessage, Result<LaunchInstanceResult, UserInstanceActionFailure>>(13);
-		ToController.Add<SendCommandToInstanceMessage, InstanceActionResult<SendCommandToInstanceResult>>(14);
+		ToController.Add<StopInstanceMessage, Result<StopInstanceResult, UserInstanceActionFailure>>(14);
-		ToController.Add<GetMinecraftVersionsMessage, ImmutableArray<MinecraftVersion>>(15);
+		ToController.Add<SendCommandToInstanceMessage, Result<SendCommandToInstanceResult, UserInstanceActionFailure>>(15);
-		ToController.Add<GetAgentJavaRuntimesMessage, ImmutableDictionary<Guid, ImmutableArray<TaggedJavaRuntime>>>(16);
+		ToController.Add<GetMinecraftVersionsMessage, ImmutableArray<MinecraftVersion>>(16);
-		ToController.Add<GetAuditLogMessage, ImmutableArray<AuditLogItem>>(17);
+		ToController.Add<GetAgentJavaRuntimesMessage, ImmutableDictionary<Guid, ImmutableArray<TaggedJavaRuntime>>>(17);
-		ToController.Add<GetEventLogMessage, ImmutableArray<EventLogItem>>(18);
+		ToController.Add<GetAuditLogMessage, Result<ImmutableArray<AuditLogItem>, UserActionFailure>>(18);
+		ToController.Add<GetEventLogMessage, Result<ImmutableArray<EventLogItem>, UserActionFailure>>(19);
 		ToController.Add<ReplyMessage>(127);
 		
 		ToWeb.Add<RegisterWebResultMessage>(0);
 		ToWeb.Add<RefreshAgentsMessage>(1);
 		ToWeb.Add<RefreshInstancesMessage>(2);
 		ToWeb.Add<InstanceOutputMessage>(3);
+		ToWeb.Add<RefreshUserSessionMessage>(4);
 		ToWeb.Add<ReplyMessage>(127);
 	}
 	

Controller/Phantom.Controller.Database.Postgres/Migrations/20240407211636_UserAgentAccess.Designer.cs

@@ -0,0 +1,353 @@
+// <auto-generated />
+using System;
+using System.Text.Json;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+using Npgsql.EntityFrameworkCore.PostgreSQL.Metadata;
+using Phantom.Controller.Database;
+
+#nullable disable
+
+namespace Phantom.Controller.Database.Postgres.Migrations
+{
+    [DbContext(typeof(ApplicationDbContext))]
+    [Migration("20240407211636_UserAgentAccess")]
+    partial class UserAgentAccess
+    {
+        /// <inheritdoc />
+        protected override void BuildTargetModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder
+                .HasAnnotation("ProductVersion", "8.0.0")
+                .HasAnnotation("Relational:MaxIdentifierLength", 63);
+
+            NpgsqlModelBuilderExtensions.UseIdentityByDefaultColumns(modelBuilder);
+
+            modelBuilder.Entity("Phantom.Controller.Database.Entities.AgentEntity", b =>
+                {
+                    b.Property<Guid>("AgentGuid")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("uuid");
+
+                    b.Property<string>("BuildVersion")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<int>("MaxInstances")
+                        .HasColumnType("integer");
+
+                    b.Property<ushort>("MaxMemory")
+                        .HasColumnType("integer");
+
+                    b.Property<string>("Name")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<int>("ProtocolVersion")
+                        .HasColumnType("integer");
+
+                    b.HasKey("AgentGuid");
+
+                    b.ToTable("Agents", "agents");
+                });
+
+            modelBuilder.Entity("Phantom.Controller.Database.Entities.AuditLogEntity", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("bigint");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<long>("Id"));
+
+                    b.Property<JsonDocument>("Data")
+                        .HasColumnType("jsonb");
+
+                    b.Property<string>("EventType")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<string>("SubjectId")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<string>("SubjectType")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<Guid?>("UserGuid")
+                        .HasColumnType("uuid");
+
+                    b.Property<DateTime>("UtcTime")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("UserGuid");
+
+                    b.ToTable("AuditLog", "system");
+                });
+
+            modelBuilder.Entity("Phantom.Controller.Database.Entities.EventLogEntity", b =>
+                {
+                    b.Property<Guid>("EventGuid")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("uuid");
+
+                    b.Property<Guid?>("AgentGuid")
+                        .HasColumnType("uuid");
+
+                    b.Property<JsonDocument>("Data")
+                        .HasColumnType("jsonb");
+
+                    b.Property<string>("EventType")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<string>("SubjectId")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<string>("SubjectType")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<DateTime>("UtcTime")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.HasKey("EventGuid");
+
+                    b.ToTable("EventLog", "system");
+                });
+
+            modelBuilder.Entity("Phantom.Controller.Database.Entities.InstanceEntity", b =>
+                {
+                    b.Property<Guid>("InstanceGuid")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("uuid");
+
+                    b.Property<Guid>("AgentGuid")
+                        .HasColumnType("uuid");
+
+                    b.Property<string>("InstanceName")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<Guid>("JavaRuntimeGuid")
+                        .HasColumnType("uuid");
+
+                    b.Property<string>("JvmArguments")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<bool>("LaunchAutomatically")
+                        .HasColumnType("boolean");
+
+                    b.Property<ushort>("MemoryAllocation")
+                        .HasColumnType("integer");
+
+                    b.Property<string>("MinecraftServerKind")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<string>("MinecraftVersion")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<int>("RconPort")
+                        .HasColumnType("integer");
+
+                    b.Property<int>("ServerPort")
+                        .HasColumnType("integer");
+
+                    b.HasKey("InstanceGuid");
+
+                    b.ToTable("Instances", "agents");
+                });
+
+            modelBuilder.Entity("Phantom.Controller.Database.Entities.PermissionEntity", b =>
+                {
+                    b.Property<string>("Id")
+                        .HasColumnType("text");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("Permissions", "identity");
+                });
+
+            modelBuilder.Entity("Phantom.Controller.Database.Entities.RoleEntity", b =>
+                {
+                    b.Property<Guid>("RoleGuid")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("uuid");
+
+                    b.Property<string>("Name")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.HasKey("RoleGuid");
+
+                    b.ToTable("Roles", "identity");
+                });
+
+            modelBuilder.Entity("Phantom.Controller.Database.Entities.RolePermissionEntity", b =>
+                {
+                    b.Property<Guid>("RoleGuid")
+                        .HasColumnType("uuid");
+
+                    b.Property<string>("PermissionId")
+                        .HasColumnType("text");
+
+                    b.HasKey("RoleGuid", "PermissionId");
+
+                    b.HasIndex("PermissionId");
+
+                    b.ToTable("RolePermissions", "identity");
+                });
+
+            modelBuilder.Entity("Phantom.Controller.Database.Entities.UserAgentAccessEntity", b =>
+                {
+                    b.Property<Guid>("UserGuid")
+                        .HasColumnType("uuid");
+
+                    b.Property<Guid>("AgentGuid")
+                        .HasColumnType("uuid");
+
+                    b.HasKey("UserGuid", "AgentGuid");
+
+                    b.HasIndex("AgentGuid");
+
+                    b.ToTable("UserAgentAccess", "identity");
+                });
+
+            modelBuilder.Entity("Phantom.Controller.Database.Entities.UserEntity", b =>
+                {
+                    b.Property<Guid>("UserGuid")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("uuid");
+
+                    b.Property<string>("Name")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<string>("PasswordHash")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.HasKey("UserGuid");
+
+                    b.HasIndex("Name")
+                        .IsUnique();
+
+                    b.ToTable("Users", "identity");
+                });
+
+            modelBuilder.Entity("Phantom.Controller.Database.Entities.UserPermissionEntity", b =>
+                {
+                    b.Property<Guid>("UserGuid")
+                        .HasColumnType("uuid");
+
+                    b.Property<string>("PermissionId")
+                        .HasColumnType("text");
+
+                    b.HasKey("UserGuid", "PermissionId");
+
+                    b.HasIndex("PermissionId");
+
+                    b.ToTable("UserPermissions", "identity");
+                });
+
+            modelBuilder.Entity("Phantom.Controller.Database.Entities.UserRoleEntity", b =>
+                {
+                    b.Property<Guid>("UserGuid")
+                        .HasColumnType("uuid");
+
+                    b.Property<Guid>("RoleGuid")
+                        .HasColumnType("uuid");
+
+                    b.HasKey("UserGuid", "RoleGuid");
+
+                    b.HasIndex("RoleGuid");
+
+                    b.ToTable("UserRoles", "identity");
+                });
+
+            modelBuilder.Entity("Phantom.Controller.Database.Entities.AuditLogEntity", b =>
+                {
+                    b.HasOne("Phantom.Controller.Database.Entities.UserEntity", "User")
+                        .WithMany()
+                        .HasForeignKey("UserGuid")
+                        .OnDelete(DeleteBehavior.SetNull);
+
+                    b.Navigation("User");
+                });
+
+            modelBuilder.Entity("Phantom.Controller.Database.Entities.RolePermissionEntity", b =>
+                {
+                    b.HasOne("Phantom.Controller.Database.Entities.PermissionEntity", null)
+                        .WithMany()
+                        .HasForeignKey("PermissionId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("Phantom.Controller.Database.Entities.RoleEntity", null)
+                        .WithMany()
+                        .HasForeignKey("RoleGuid")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("Phantom.Controller.Database.Entities.UserAgentAccessEntity", b =>
+                {
+                    b.HasOne("Phantom.Controller.Database.Entities.AgentEntity", null)
+                        .WithMany()
+                        .HasForeignKey("AgentGuid")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("Phantom.Controller.Database.Entities.UserEntity", null)
+                        .WithMany()
+                        .HasForeignKey("UserGuid")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("Phantom.Controller.Database.Entities.UserPermissionEntity", b =>
+                {
+                    b.HasOne("Phantom.Controller.Database.Entities.PermissionEntity", null)
+                        .WithMany()
+                        .HasForeignKey("PermissionId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("Phantom.Controller.Database.Entities.UserEntity", null)
+                        .WithMany()
+                        .HasForeignKey("UserGuid")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("Phantom.Controller.Database.Entities.UserRoleEntity", b =>
+                {
+                    b.HasOne("Phantom.Controller.Database.Entities.RoleEntity", "Role")
+                        .WithMany()
+                        .HasForeignKey("RoleGuid")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("Phantom.Controller.Database.Entities.UserEntity", "User")
+                        .WithMany()
+                        .HasForeignKey("UserGuid")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Role");
+
+                    b.Navigation("User");
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}

Controller/Phantom.Controller.Database.Postgres/Migrations/20240407211636_UserAgentAccess.cs

@@ -0,0 +1,56 @@
+using System;
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace Phantom.Controller.Database.Postgres.Migrations
+{
+    /// <inheritdoc />
+    public partial class UserAgentAccess : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.CreateTable(
+                name: "UserAgentAccess",
+                schema: "identity",
+                columns: table => new
+                {
+                    UserGuid = table.Column<Guid>(type: "uuid", nullable: false),
+                    AgentGuid = table.Column<Guid>(type: "uuid", nullable: false)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_UserAgentAccess", x => new { x.UserGuid, x.AgentGuid });
+                    table.ForeignKey(
+                        name: "FK_UserAgentAccess_Agents_AgentGuid",
+                        column: x => x.AgentGuid,
+                        principalSchema: "agents",
+                        principalTable: "Agents",
+                        principalColumn: "AgentGuid",
+                        onDelete: ReferentialAction.Cascade);
+                    table.ForeignKey(
+                        name: "FK_UserAgentAccess_Users_UserGuid",
+                        column: x => x.UserGuid,
+                        principalSchema: "identity",
+                        principalTable: "Users",
+                        principalColumn: "UserGuid",
+                        onDelete: ReferentialAction.Cascade);
+                });
+
+            migrationBuilder.CreateIndex(
+                name: "IX_UserAgentAccess_AgentGuid",
+                schema: "identity",
+                table: "UserAgentAccess",
+                column: "AgentGuid");
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropTable(
+                name: "UserAgentAccess",
+                schema: "identity");
+        }
+    }
+}

Controller/Phantom.Controller.Database.Postgres/Migrations/ApplicationDbContextModelSnapshot.cs

@@ -18,7 +18,7 @@ namespace Phantom.Controller.Database.Postgres.Migrations
         {
 #pragma warning disable 612, 618
             modelBuilder
-                .HasAnnotation("ProductVersion", "7.0.11")
+                .HasAnnotation("ProductVersion", "8.0.0")
                 .HasAnnotation("Relational:MaxIdentifierLength", 63);
 
             NpgsqlModelBuilderExtensions.UseIdentityByDefaultColumns(modelBuilder);
@@ -204,6 +204,21 @@ namespace Phantom.Controller.Database.Postgres.Migrations
                     b.ToTable("RolePermissions", "identity");
                 });
 
+            modelBuilder.Entity("Phantom.Controller.Database.Entities.UserAgentAccessEntity", b =>
+                {
+                    b.Property<Guid>("UserGuid")
+                        .HasColumnType("uuid");
+
+                    b.Property<Guid>("AgentGuid")
+                        .HasColumnType("uuid");
+
+                    b.HasKey("UserGuid", "AgentGuid");
+
+                    b.HasIndex("AgentGuid");
+
+                    b.ToTable("UserAgentAccess", "identity");
+                });
+
             modelBuilder.Entity("Phantom.Controller.Database.Entities.UserEntity", b =>
                 {
                     b.Property<Guid>("UserGuid")
@@ -281,6 +296,21 @@ namespace Phantom.Controller.Database.Postgres.Migrations
                         .IsRequired();
                 });
 
+            modelBuilder.Entity("Phantom.Controller.Database.Entities.UserAgentAccessEntity", b =>
+                {
+                    b.HasOne("Phantom.Controller.Database.Entities.AgentEntity", null)
+                        .WithMany()
+                        .HasForeignKey("AgentGuid")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("Phantom.Controller.Database.Entities.UserEntity", null)
+                        .WithMany()
+                        .HasForeignKey("UserGuid")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
             modelBuilder.Entity("Phantom.Controller.Database.Entities.UserPermissionEntity", b =>
                 {
                     b.HasOne("Phantom.Controller.Database.Entities.PermissionEntity", null)

Controller/Phantom.Controller.Database/ApplicationDbContext.cs

@@ -20,6 +20,7 @@ public class ApplicationDbContext : DbContext {
 	public DbSet<UserRoleEntity> UserRoles { get; init; } = null!;
 	public DbSet<UserPermissionEntity> UserPermissions { get; init; } = null!;
 	public DbSet<RolePermissionEntity> RolePermissions { get; init; } = null!;
+	public DbSet<UserAgentAccessEntity> UserAgentAccess { get; init; } = null!;
 	
 	public DbSet<AgentEntity> Agents { get; init; } = null!;
 	public DbSet<InstanceEntity> Instances { get; init; } = null!;
@@ -62,6 +63,12 @@ public class ApplicationDbContext : DbContext {
 			b.HasOne<RoleEntity>().WithMany().HasForeignKey(static e => e.RoleGuid).IsRequired().OnDelete(DeleteBehavior.Cascade);
 			b.HasOne<PermissionEntity>().WithMany().HasForeignKey(static e => e.PermissionId).IsRequired().OnDelete(DeleteBehavior.Cascade);
 		});
+		
+		builder.Entity<UserAgentAccessEntity>(static b => {
+			b.HasKey(static e => new { UserId = e.UserGuid, AgentId = e.AgentGuid });
+			b.HasOne<UserEntity>().WithMany().HasForeignKey(static e => e.UserGuid).IsRequired().OnDelete(DeleteBehavior.Cascade);
+			b.HasOne<AgentEntity>().WithMany().HasForeignKey(static e => e.AgentGuid).IsRequired().OnDelete(DeleteBehavior.Cascade);
+		});
 	}
 	
 	protected override void ConfigureConventions(ModelConfigurationBuilder builder) {

Controller/Phantom.Controller.Database/Entities/UserAgentAccessEntity.cs

@@ -0,0 +1,14 @@
+using System.ComponentModel.DataAnnotations.Schema;
+
+namespace Phantom.Controller.Database.Entities;
+
+[Table("UserAgentAccess", Schema = "identity")]
+public sealed class UserAgentAccessEntity {
+	public Guid UserGuid { get; init; }
+	public Guid AgentGuid { get; init; }
+	
+	public UserAgentAccessEntity(Guid userGuid, Guid agentGuid) {
+		UserGuid = userGuid;
+		AgentGuid = agentGuid;
+	}
+}

Controller/Phantom.Controller.Database/Repositories/EventLogRepository.cs

@@ -17,11 +17,12 @@ public sealed class EventLogRepository {
 		db.Ctx.EventLog.Add(new EventLogEntity(eventGuid, utcTime, agentGuid, eventType, subjectId, extra));
 	}
 	
-	public Task<ImmutableArray<EventLogItem>> GetMostRecentItems(int count, CancellationToken cancellationToken) {
+	public Task<ImmutableArray<EventLogItem>> GetMostRecentItems(ImmutableHashSet<Guid> agentGuids, int count, CancellationToken cancellationToken) {
 		return db.Ctx
 		         .EventLog
 		         .AsQueryable()
 		         .OrderByDescending(static entity => entity.UtcTime)
+		         .Where(entity => entity.AgentGuid == null || agentGuids.Contains(entity.AgentGuid.Value))
 		         .Take(count)
 		         .AsAsyncEnumerable()
 		         .Select(static entity => new EventLogItem(entity.UtcTime, entity.AgentGuid, entity.EventType, entity.SubjectType, entity.SubjectId, entity.Data?.RootElement.ToString()))

Controller/Phantom.Controller.Database/Repositories/PermissionRepository.cs

@@ -0,0 +1,35 @@
+using System.Collections.Immutable;
+using Microsoft.EntityFrameworkCore;
+using Phantom.Common.Data.Web.Users;
+using Phantom.Controller.Database.Entities;
+using Phantom.Utils.Collections;
+
+namespace Phantom.Controller.Database.Repositories;
+
+public sealed class PermissionRepository {
+	private readonly ILazyDbContext db;
+	
+	public PermissionRepository(ILazyDbContext db) {
+		this.db = db;
+	}
+	
+	public async Task<PermissionSet> GetAllUserPermissions(UserEntity user) {
+		var userPermissions = db.Ctx.UserPermissions
+		                        .Where(up => up.UserGuid == user.UserGuid)
+		                        .Select(static up => up.PermissionId);
+		
+		var rolePermissions = db.Ctx.UserRoles
+		                        .Where(ur => ur.UserGuid == user.UserGuid)
+		                        .Join(db.Ctx.RolePermissions, static ur => ur.RoleGuid, static rp => rp.RoleGuid, static (ur, rp) => rp.PermissionId);
+		
+		return new PermissionSet(await userPermissions.Union(rolePermissions).AsAsyncEnumerable().ToImmutableSetAsync());
+	}
+	
+	public Task<ImmutableHashSet<Guid>> GetManagedAgentGuids(UserEntity user) {
+		return db.Ctx.UserAgentAccess
+		         .Where(ua => ua.UserGuid == user.UserGuid)
+		         .Select(static ua => ua.AgentGuid)
+		         .AsAsyncEnumerable()
+		         .ToImmutableSetAsync();
+	}
+}

Controller/Phantom.Controller.Database/Repositories/RoleRepository.cs

@@ -1,9 +1,9 @@
 using System.Collections.Immutable;
 using Microsoft.EntityFrameworkCore;
+using Phantom.Common.Data;
 using Phantom.Common.Data.Web.Users;
 using Phantom.Controller.Database.Entities;
 using Phantom.Utils.Collections;
-using Phantom.Utils.Tasks;
 
 namespace Phantom.Controller.Database.Repositories;
 

Controller/Phantom.Controller.Database/Repositories/UserRepository.cs

@@ -1,12 +1,12 @@
 using System.Collections.Immutable;
 using Microsoft.EntityFrameworkCore;
+using Phantom.Common.Data;
 using Phantom.Common.Data.Web.Users;
 using Phantom.Common.Data.Web.Users.AddUserErrors;
 using Phantom.Common.Data.Web.Users.PasswordRequirementViolations;
 using Phantom.Common.Data.Web.Users.UsernameRequirementViolations;
 using Phantom.Controller.Database.Entities;
 using Phantom.Utils.Collections;
-using Phantom.Utils.Tasks;
 
 namespace Phantom.Controller.Database.Repositories;
 

Controller/Phantom.Controller.Services/Agents/AgentActor.cs

@@ -13,11 +13,13 @@ using Phantom.Common.Data.Web.Minecraft;
 using Phantom.Common.Messages.Agent;
 using Phantom.Common.Messages.Agent.ToAgent;
 using Phantom.Controller.Database;
+using Phantom.Controller.Database.Entities;
 using Phantom.Controller.Minecraft;
 using Phantom.Controller.Services.Instances;
 using Phantom.Utils.Actor;
 using Phantom.Utils.Actor.Mailbox;
 using Phantom.Utils.Actor.Tasks;
+using Phantom.Utils.Collections;
 using Phantom.Utils.Logging;
 using Phantom.Utils.Rpc.Runtime;
 using Serilog;
@@ -92,11 +94,12 @@ sealed class AgentActor : ReceiveActor<AgentActor.ICommand> {
 		Receive<NotifyIsAliveCommand>(NotifyIsAlive);
 		Receive<UpdateStatsCommand>(UpdateStats);
 		Receive<UpdateJavaRuntimesCommand>(UpdateJavaRuntimes);
-		ReceiveAndReplyLater<CreateOrUpdateInstanceCommand, InstanceActionResult<CreateOrUpdateInstanceResult>>(CreateOrUpdateInstance);
+		ReceiveAndReplyLater<CreateOrUpdateInstanceCommand, Result<CreateOrUpdateInstanceResult, InstanceActionFailure>>(CreateOrUpdateInstance);
 		Receive<UpdateInstanceStatusCommand>(UpdateInstanceStatus);
-		ReceiveAndReplyLater<LaunchInstanceCommand, InstanceActionResult<LaunchInstanceResult>>(LaunchInstance);
+		Receive<UpdateInstancePlayerCountsCommand>(UpdateInstancePlayerCounts);
-		ReceiveAndReplyLater<StopInstanceCommand, InstanceActionResult<StopInstanceResult>>(StopInstance);
+		ReceiveAndReplyLater<LaunchInstanceCommand, Result<LaunchInstanceResult, InstanceActionFailure>>(LaunchInstance);
-		ReceiveAndReplyLater<SendCommandToInstanceCommand, InstanceActionResult<SendCommandToInstanceResult>>(SendMinecraftCommand);
+		ReceiveAndReplyLater<StopInstanceCommand, Result<StopInstanceResult, InstanceActionFailure>>(StopInstance);
+		ReceiveAndReplyLater<SendCommandToInstanceCommand, Result<SendCommandToInstanceResult, InstanceActionFailure>>(SendMinecraftCommand);
 		Receive<ReceiveInstanceDataCommand>(ReceiveInstanceData);
 	}
 	
@@ -144,20 +147,20 @@ sealed class AgentActor : ReceiveActor<AgentActor.ICommand> {
 		}
 	}
 	
-	private Task<InstanceActionResult<TReply>> RequestInstance<TCommand, TReply>(Guid instanceGuid, TCommand command) where TCommand : InstanceActor.ICommand, ICanReply<InstanceActionResult<TReply>> {
+	private async Task<Result<TReply, InstanceActionFailure>> RequestInstance<TCommand, TReply>(Guid instanceGuid, TCommand command) where TCommand : InstanceActor.ICommand, ICanReply<Result<TReply, InstanceActionFailure>> {
 		if (instanceActorByGuid.TryGetValue(instanceGuid, out var instance)) {
-			return instance.Request(command, cancellationToken);
+			return await instance.Request(command, cancellationToken);
 		}
 		else {
 			Logger.Warning("Could not deliver command {CommandType} to instance {InstanceGuid}, instance not found.", command.GetType().Name, instanceGuid);
-			return Task.FromResult(InstanceActionResult.General<TReply>(InstanceActionGeneralResult.InstanceDoesNotExist));
+			return InstanceActionFailure.InstanceDoesNotExist;
 		}
 	}
 	
 	private async Task<ImmutableArray<ConfigureInstanceMessage>> PrepareInitialConfigurationMessages() {
 		var configurationMessages = ImmutableArray.CreateBuilder<ConfigureInstanceMessage>();
 		
-		foreach (var (instanceGuid, instanceConfiguration, _, launchAutomatically) in instanceDataByGuid.Values.ToImmutableArray()) {
+		foreach (var (instanceGuid, instanceConfiguration, _, _, launchAutomatically) in instanceDataByGuid.Values.ToImmutableArray()) {
 			var serverExecutableInfo = await minecraftVersions.GetServerExecutableInfo(instanceConfiguration.MinecraftVersion, cancellationToken);
 			configurationMessages.Add(new ConfigureInstanceMessage(instanceGuid, instanceConfiguration, new InstanceLaunchProperties(serverExecutableInfo), launchAutomatically));
 		}
@@ -181,34 +184,44 @@ sealed class AgentActor : ReceiveActor<AgentActor.ICommand> {
 	
 	public sealed record UpdateJavaRuntimesCommand(ImmutableArray<TaggedJavaRuntime> JavaRuntimes) : ICommand;
 	
-	public sealed record CreateOrUpdateInstanceCommand(Guid AuditLogUserGuid, Guid InstanceGuid, InstanceConfiguration Configuration) : ICommand, ICanReply<InstanceActionResult<CreateOrUpdateInstanceResult>>;
+	public sealed record CreateOrUpdateInstanceCommand(Guid LoggedInUserGuid, Guid InstanceGuid, InstanceConfiguration Configuration) : ICommand, ICanReply<Result<CreateOrUpdateInstanceResult, InstanceActionFailure>>;
 	
 	public sealed record UpdateInstanceStatusCommand(Guid InstanceGuid, IInstanceStatus Status) : ICommand;
 	
-	public sealed record LaunchInstanceCommand(Guid InstanceGuid, Guid AuditLogUserGuid) : ICommand, ICanReply<InstanceActionResult<LaunchInstanceResult>>;
+	public sealed record UpdateInstancePlayerCountsCommand(Guid InstanceGuid, InstancePlayerCounts? PlayerCounts) : ICommand;
 	
-	public sealed record StopInstanceCommand(Guid InstanceGuid, Guid AuditLogUserGuid, MinecraftStopStrategy StopStrategy) : ICommand, ICanReply<InstanceActionResult<StopInstanceResult>>;
+	public sealed record LaunchInstanceCommand(Guid LoggedInUserGuid, Guid InstanceGuid) : ICommand, ICanReply<Result<LaunchInstanceResult, InstanceActionFailure>>;
 	
-	public sealed record SendCommandToInstanceCommand(Guid InstanceGuid, Guid AuditLogUserGuid, string Command) : ICommand, ICanReply<InstanceActionResult<SendCommandToInstanceResult>>;
+	public sealed record StopInstanceCommand(Guid LoggedInUserGuid, Guid InstanceGuid, MinecraftStopStrategy StopStrategy) : ICommand, ICanReply<Result<StopInstanceResult, InstanceActionFailure>>;
+	
+	public sealed record SendCommandToInstanceCommand(Guid LoggedInUserGuid, Guid InstanceGuid, string Command) : ICommand, ICanReply<Result<SendCommandToInstanceResult, InstanceActionFailure>>;
 	
 	public sealed record ReceiveInstanceDataCommand(Instance Instance) : ICommand, IJumpAhead;
 	
 	private async Task Initialize(InitializeCommand command) {
-		await using var ctx = dbProvider.Eager();
+		ImmutableArray<InstanceEntity> instanceEntities;
-		await foreach (var entity in ctx.Instances.Where(instance => instance.AgentGuid == agentGuid).AsAsyncEnumerable().WithCancellation(cancellationToken)) {
+		await using (var ctx = dbProvider.Eager()) {
+			instanceEntities = await ctx.Instances.Where(instance => instance.AgentGuid == agentGuid).AsAsyncEnumerable().ToImmutableArrayCatchingExceptionsAsync(OnException, cancellationToken);
+		}
+		
+		static void OnException(Exception e) {
+			Logger.Error(e, "Could not load instance from database.");
+		}
+		
+		foreach (var instanceEntity in instanceEntities) {
 			var instanceConfiguration = new InstanceConfiguration(
-				entity.AgentGuid,
+				instanceEntity.AgentGuid,
-				entity.InstanceName,
+				instanceEntity.InstanceName,
-				entity.ServerPort,
+				instanceEntity.ServerPort,
-				entity.RconPort,
+				instanceEntity.RconPort,
-				entity.MinecraftVersion,
+				instanceEntity.MinecraftVersion,
-				entity.MinecraftServerKind,
+				instanceEntity.MinecraftServerKind,
-				entity.MemoryAllocation,
+				instanceEntity.MemoryAllocation,
-				entity.JavaRuntimeGuid,
+				instanceEntity.JavaRuntimeGuid,
-				JvmArgumentsHelper.Split(entity.JvmArguments)
+				JvmArgumentsHelper.Split(instanceEntity.JvmArguments)
 			);
 			
-			CreateNewInstance(Instance.Offline(entity.InstanceGuid, instanceConfiguration, entity.LaunchAutomatically));
+			CreateNewInstance(Instance.Offline(instanceEntity.InstanceGuid, instanceConfiguration, instanceEntity.LaunchAutomatically));
 		}
 	}
 	
@@ -270,15 +283,15 @@ sealed class AgentActor : ReceiveActor<AgentActor.ICommand> {
 		controllerState.UpdateAgentJavaRuntimes(agentGuid, javaRuntimes);
 	}
 	
-	private Task<InstanceActionResult<CreateOrUpdateInstanceResult>> CreateOrUpdateInstance(CreateOrUpdateInstanceCommand command) {
+	private Task<Result<CreateOrUpdateInstanceResult, InstanceActionFailure>> CreateOrUpdateInstance(CreateOrUpdateInstanceCommand command) {
 		var instanceConfiguration = command.Configuration;
 		
 		if (string.IsNullOrWhiteSpace(instanceConfiguration.InstanceName)) {
-			return Task.FromResult(InstanceActionResult.Concrete(CreateOrUpdateInstanceResult.InstanceNameMustNotBeEmpty));
+			return Task.FromResult<Result<CreateOrUpdateInstanceResult, InstanceActionFailure>>(CreateOrUpdateInstanceResult.InstanceNameMustNotBeEmpty);
 		}
 		
 		if (instanceConfiguration.MemoryAllocation <= RamAllocationUnits.Zero) {
-			return Task.FromResult(InstanceActionResult.Concrete(CreateOrUpdateInstanceResult.InstanceMemoryMustNotBeZero));
+			return Task.FromResult<Result<CreateOrUpdateInstanceResult, InstanceActionFailure>>(CreateOrUpdateInstanceResult.InstanceMemoryMustNotBeZero);
 		}
 		
 		return minecraftVersions.GetServerExecutableInfo(instanceConfiguration.MinecraftVersion, cancellationToken)
@@ -286,9 +299,9 @@ sealed class AgentActor : ReceiveActor<AgentActor.ICommand> {
 		                        .Unwrap();
 	}
 	
-	private Task<InstanceActionResult<CreateOrUpdateInstanceResult>> CreateOrUpdateInstance1(FileDownloadInfo? serverExecutableInfo, CreateOrUpdateInstanceCommand command) {
+	private Task<Result<CreateOrUpdateInstanceResult, InstanceActionFailure>> CreateOrUpdateInstance1(FileDownloadInfo? serverExecutableInfo, CreateOrUpdateInstanceCommand command) {
 		if (serverExecutableInfo == null) {
-			return Task.FromResult(InstanceActionResult.Concrete(CreateOrUpdateInstanceResult.MinecraftVersionDownloadInfoNotFound));
+			return Task.FromResult<Result<CreateOrUpdateInstanceResult, InstanceActionFailure>>(CreateOrUpdateInstanceResult.MinecraftVersionDownloadInfoNotFound);
 		}
 		
 		var instanceConfiguration = command.Configuration;
@@ -298,13 +311,13 @@ sealed class AgentActor : ReceiveActor<AgentActor.ICommand> {
 			instanceActorRef = CreateNewInstance(Instance.Offline(command.InstanceGuid, instanceConfiguration));
 		}
 		
-		var configureInstanceCommand = new InstanceActor.ConfigureInstanceCommand(command.AuditLogUserGuid, command.InstanceGuid, instanceConfiguration, new InstanceLaunchProperties(serverExecutableInfo), isCreatingInstance);
+		var configureInstanceCommand = new InstanceActor.ConfigureInstanceCommand(command.LoggedInUserGuid, command.InstanceGuid, instanceConfiguration, new InstanceLaunchProperties(serverExecutableInfo), isCreatingInstance);
 		
 		return instanceActorRef.Request(configureInstanceCommand, cancellationToken)
 		                       .ContinueOnActor(CreateOrUpdateInstance2, configureInstanceCommand);
 	}
 	
-	private InstanceActionResult<CreateOrUpdateInstanceResult> CreateOrUpdateInstance2(InstanceActionResult<ConfigureInstanceResult> result, InstanceActor.ConfigureInstanceCommand command) {
+	private Result<CreateOrUpdateInstanceResult, InstanceActionFailure> CreateOrUpdateInstance2(Result<ConfigureInstanceResult, InstanceActionFailure> result, InstanceActor.ConfigureInstanceCommand command) {
 		var instanceGuid = command.InstanceGuid;
 		var instanceName = command.Configuration.InstanceName;
 		var isCreating = command.IsCreatingInstance;
@@ -312,34 +325,40 @@ sealed class AgentActor : ReceiveActor<AgentActor.ICommand> {
 		if (result.Is(ConfigureInstanceResult.Success)) {
 			string action = isCreating ? "Added" : "Edited";
 			string relation = isCreating ? "to agent" : "in agent";
+			
 			Logger.Information(action + " instance \"{InstanceName}\" (GUID {InstanceGuid}) " + relation + " \"{AgentName}\".", instanceName, instanceGuid, configuration.AgentName);
+			
+			return CreateOrUpdateInstanceResult.Success;
 		}
 		else {
 			string action = isCreating ? "adding" : "editing";
 			string relation = isCreating ? "to agent" : "in agent";
-			Logger.Information("Failed " + action + " instance \"{InstanceName}\" (GUID {InstanceGuid}) " + relation + " \"{AgentName}\". {ErrorMessage}", instanceName, instanceGuid, configuration.AgentName, result.ToSentence(ConfigureInstanceResultExtensions.ToSentence));
+			string reason = result.Into(ConfigureInstanceResultExtensions.ToSentence, InstanceActionFailureExtensions.ToSentence);
-		}
 			
-		return result.Map(static result => result switch {
+			Logger.Information("Failed " + action + " instance \"{InstanceName}\" (GUID {InstanceGuid}) " + relation + " \"{AgentName}\". {ErrorMessage}", instanceName, instanceGuid, configuration.AgentName, reason);
-			ConfigureInstanceResult.Success => CreateOrUpdateInstanceResult.Success,
+			
-			_                               => CreateOrUpdateInstanceResult.UnknownError
+			return CreateOrUpdateInstanceResult.UnknownError;
-		});
+		}
 	}
 	
 	private void UpdateInstanceStatus(UpdateInstanceStatusCommand command) {
 		TellInstance(command.InstanceGuid, new InstanceActor.SetStatusCommand(command.Status));
 	}
 	
-	private Task<InstanceActionResult<LaunchInstanceResult>> LaunchInstance(LaunchInstanceCommand command) {
+	private void UpdateInstancePlayerCounts(UpdateInstancePlayerCountsCommand command) {
-		return RequestInstance<InstanceActor.LaunchInstanceCommand, LaunchInstanceResult>(command.InstanceGuid, new InstanceActor.LaunchInstanceCommand(command.AuditLogUserGuid));
+		TellInstance(command.InstanceGuid, new InstanceActor.SetPlayerCountsCommand(command.PlayerCounts));
 	}
 	
-	private Task<InstanceActionResult<StopInstanceResult>> StopInstance(StopInstanceCommand command) {
+	private Task<Result<LaunchInstanceResult, InstanceActionFailure>> LaunchInstance(LaunchInstanceCommand command) {
-		return RequestInstance<InstanceActor.StopInstanceCommand, StopInstanceResult>(command.InstanceGuid, new InstanceActor.StopInstanceCommand(command.AuditLogUserGuid, command.StopStrategy));
+		return RequestInstance<InstanceActor.LaunchInstanceCommand, LaunchInstanceResult>(command.InstanceGuid, new InstanceActor.LaunchInstanceCommand(command.LoggedInUserGuid));
 	}
 	
-	private Task<InstanceActionResult<SendCommandToInstanceResult>> SendMinecraftCommand(SendCommandToInstanceCommand command) {
+	private Task<Result<StopInstanceResult, InstanceActionFailure>> StopInstance(StopInstanceCommand command) {
-		return RequestInstance<InstanceActor.SendCommandToInstanceCommand, SendCommandToInstanceResult>(command.InstanceGuid, new InstanceActor.SendCommandToInstanceCommand(command.AuditLogUserGuid, command.Command));
+		return RequestInstance<InstanceActor.StopInstanceCommand, StopInstanceResult>(command.InstanceGuid, new InstanceActor.StopInstanceCommand(command.LoggedInUserGuid, command.StopStrategy));
+	}
+	
+	private Task<Result<SendCommandToInstanceResult, InstanceActionFailure>> SendMinecraftCommand(SendCommandToInstanceCommand command) {
+		return RequestInstance<InstanceActor.SendCommandToInstanceCommand, SendCommandToInstanceResult>(command.InstanceGuid, new InstanceActor.SendCommandToInstanceCommand(command.LoggedInUserGuid, command.Command));
 	}
 	
 	private void ReceiveInstanceData(ReceiveInstanceDataCommand command) {

Controller/Phantom.Controller.Services/Agents/AgentManager.cs

@@ -1,13 +1,16 @@
 using System.Collections.Concurrent;
+using System.Collections.Immutable;
 using Akka.Actor;
 using Phantom.Common.Data;
 using Phantom.Common.Data.Agent;
 using Phantom.Common.Data.Replies;
 using Phantom.Common.Data.Web.Agent;
+using Phantom.Common.Data.Web.Users;
 using Phantom.Common.Messages.Agent;
 using Phantom.Common.Messages.Agent.ToAgent;
 using Phantom.Controller.Database;
 using Phantom.Controller.Minecraft;
+using Phantom.Controller.Services.Users.Sessions;
 using Phantom.Utils.Actor;
 using Phantom.Utils.Logging;
 using Phantom.Utils.Rpc.Runtime;
@@ -22,17 +25,19 @@ sealed class AgentManager {
 	private readonly AuthToken authToken;
 	private readonly ControllerState controllerState;
 	private readonly MinecraftVersions minecraftVersions;
+	private readonly UserLoginManager userLoginManager;
 	private readonly IDbContextProvider dbProvider;
 	private readonly CancellationToken cancellationToken;
 	
 	private readonly ConcurrentDictionary<Guid, ActorRef<AgentActor.ICommand>> agentsByGuid = new ();
 	private readonly Func<Guid, AgentConfiguration, ActorRef<AgentActor.ICommand>> addAgentActorFactory;
 	
-	public AgentManager(IActorRefFactory actorSystem, AuthToken authToken, ControllerState controllerState, MinecraftVersions minecraftVersions, IDbContextProvider dbProvider, CancellationToken cancellationToken) {
+	public AgentManager(IActorRefFactory actorSystem, AuthToken authToken, ControllerState controllerState, MinecraftVersions minecraftVersions, UserLoginManager userLoginManager, IDbContextProvider dbProvider, CancellationToken cancellationToken) {
 		this.actorSystem = actorSystem;
 		this.authToken = authToken;
 		this.controllerState = controllerState;
 		this.minecraftVersions = minecraftVersions;
+		this.userLoginManager = userLoginManager;
 		this.dbProvider = dbProvider;
 		this.cancellationToken = cancellationToken;
 		
@@ -83,12 +88,18 @@ sealed class AgentManager {
 		}
 	}
 	
-	public async Task<InstanceActionResult<TReply>> DoInstanceAction<TCommand, TReply>(Guid agentGuid, TCommand command) where TCommand : class, AgentActor.ICommand, ICanReply<InstanceActionResult<TReply>> {
+	public async Task<Result<TReply, UserInstanceActionFailure>> DoInstanceAction<TCommand, TReply>(Permission requiredPermission, ImmutableArray<byte> authToken, Guid agentGuid, Func<Guid, TCommand> commandFactoryFromLoggedInUserGuid) where TCommand : class, AgentActor.ICommand, ICanReply<Result<TReply, InstanceActionFailure>> {
-		if (agentsByGuid.TryGetValue(agentGuid, out var agent)) {
+		var loggedInUser = userLoginManager.GetLoggedInUser(authToken);
-			return await agent.Request(command, cancellationToken);
+		if (!loggedInUser.HasAccessToAgent(agentGuid) || !loggedInUser.CheckPermission(requiredPermission)) {
+			return (UserInstanceActionFailure) UserActionFailure.NotAuthorized;
 		}
-		else {
+		
-			return InstanceActionResult.General<TReply>(InstanceActionGeneralResult.AgentDoesNotExist);
+		if (!agentsByGuid.TryGetValue(agentGuid, out var agent)) {
+			return (UserInstanceActionFailure) InstanceActionFailure.AgentDoesNotExist;
 		}
+		
+		var command = commandFactoryFromLoggedInUserGuid(loggedInUser.Guid!.Value);
+		var result = await agent.Request(command, cancellationToken);
+		return result.MapError(static error => (UserInstanceActionFailure) error);
 	}
 }

Controller/Phantom.Controller.Services/ControllerServices.cs

@@ -11,6 +11,7 @@ using Phantom.Controller.Services.Events;
 using Phantom.Controller.Services.Instances;
 using Phantom.Controller.Services.Rpc;
 using Phantom.Controller.Services.Users;
+using Phantom.Controller.Services.Users.Sessions;
 using Phantom.Utils.Actor;
 using Phantom.Utils.Rpc.Runtime;
 using IMessageFromAgentToController = Phantom.Common.Messages.Agent.IMessageToController;
@@ -24,17 +25,18 @@ public sealed class ControllerServices : IDisposable {
 	private ControllerState ControllerState { get; }
 	private MinecraftVersions MinecraftVersions { get; }
 	
-	private AgentManager AgentManager { get; }
+	private AuthenticatedUserCache AuthenticatedUserCache { get; }
-	private InstanceLogManager InstanceLogManager { get; }
-	private EventLogManager EventLogManager { get; }
-
 	private UserManager UserManager { get; }
 	private RoleManager RoleManager { get; }
-	private PermissionManager PermissionManager { get; }
-
 	private UserRoleManager UserRoleManager { get; }
 	private UserLoginManager UserLoginManager { get; }
+	private PermissionManager PermissionManager { get; }
+	
+	private AgentManager AgentManager { get; }
+	private InstanceLogManager InstanceLogManager { get; }
+	
 	private AuditLogManager AuditLogManager { get; }
+	private EventLogManager EventLogManager { get; }
 	
 	public IRegistrationHandler<IMessageToAgent, IMessageFromAgentToController, RegisterAgentMessage> AgentRegistrationHandler { get; }
 	public IRegistrationHandler<IMessageToWeb, IMessageFromWebToController, RegisterWebMessage> WebRegistrationHandler { get; }
@@ -51,17 +53,18 @@ public sealed class ControllerServices : IDisposable {
 		this.ControllerState = new ControllerState();
 		this.MinecraftVersions = new MinecraftVersions();
 		
-		this.AgentManager = new AgentManager(ActorSystem, agentAuthToken, ControllerState, MinecraftVersions, dbProvider, cancellationToken);
+		this.AuthenticatedUserCache = new AuthenticatedUserCache();
-		this.InstanceLogManager = new InstanceLogManager();
+		this.UserManager = new UserManager(AuthenticatedUserCache, ControllerState, dbProvider);
-		
-		this.UserManager = new UserManager(dbProvider);
 		this.RoleManager = new RoleManager(dbProvider);
+		this.UserRoleManager = new UserRoleManager(AuthenticatedUserCache, ControllerState, dbProvider);
+		this.UserLoginManager = new UserLoginManager(AuthenticatedUserCache, UserManager, dbProvider);
 		this.PermissionManager = new PermissionManager(dbProvider);
 		
-		this.UserRoleManager = new UserRoleManager(dbProvider);
+		this.AgentManager = new AgentManager(ActorSystem, agentAuthToken, ControllerState, MinecraftVersions, UserLoginManager, dbProvider, cancellationToken);
-		this.UserLoginManager = new UserLoginManager(UserManager, PermissionManager, dbProvider);
+		this.InstanceLogManager = new InstanceLogManager();
+		
 		this.AuditLogManager = new AuditLogManager(dbProvider);
-		this.EventLogManager = new EventLogManager(ActorSystem, dbProvider, shutdownCancellationToken);
+		this.EventLogManager = new EventLogManager(ControllerState, ActorSystem, dbProvider, shutdownCancellationToken);
 		
 		this.AgentRegistrationHandler = new AgentRegistrationHandler(AgentManager, InstanceLogManager, EventLogManager);
 		this.WebRegistrationHandler = new WebRegistrationHandler(webAuthToken, ControllerState, InstanceLogManager, UserManager, RoleManager, UserRoleManager, UserLoginManager, AuditLogManager, AgentManager, MinecraftVersions, EventLogManager);

Controller/Phantom.Controller.Services/ControllerState.cs

@@ -19,6 +19,8 @@ sealed class ControllerState {
 	public ObservableState<ImmutableDictionary<Guid, ImmutableArray<TaggedJavaRuntime>>>.Receiver AgentJavaRuntimesByGuidReceiver => agentJavaRuntimesByGuid.ReceiverSide;
 	public ObservableState<ImmutableDictionary<Guid, Instance>>.Receiver InstancesByGuidReceiver => instancesByGuid.ReceiverSide;
 	
+	public event EventHandler<Guid>? UserUpdatedOrDeleted;
+	
 	public void UpdateAgent(Agent agent) {
 		agentsByGuid.PublisherSide.Publish(static (agentsByGuid, agent) => agentsByGuid.SetItem(agent.AgentGuid, agent), agent);
 	}
@@ -30,4 +32,8 @@ sealed class ControllerState {
 	public void UpdateInstance(Instance instance) {
 		instancesByGuid.PublisherSide.Publish(static (instancesByGuid, instance) => instancesByGuid.SetItem(instance.InstanceGuid, instance), instance);
 	}
+	
+	public void UpdateOrDeleteUser(Guid userGuid) {
+		UserUpdatedOrDeleted?.Invoke(null, userGuid);
+	}
 }

Controller/Phantom.Controller.Services/Events/EventLogManager.cs

@@ -1,18 +1,23 @@
 using System.Collections.Immutable;
 using Akka.Actor;
+using Phantom.Common.Data;
 using Phantom.Common.Data.Web.EventLog;
+using Phantom.Common.Data.Web.Users;
 using Phantom.Controller.Database;
 using Phantom.Controller.Database.Repositories;
+using Phantom.Controller.Services.Users.Sessions;
 using Phantom.Utils.Actor;
 
 namespace Phantom.Controller.Services.Events;
 
 sealed partial class EventLogManager {
+	private readonly ControllerState controllerState;
 	private readonly ActorRef<EventLogDatabaseStorageActor.ICommand> databaseStorageActor;
 	private readonly IDbContextProvider dbProvider;
 	private readonly CancellationToken cancellationToken;
 	
-	public EventLogManager(IActorRefFactory actorSystem, IDbContextProvider dbProvider, CancellationToken cancellationToken) {
+	public EventLogManager(ControllerState controllerState, IActorRefFactory actorSystem, IDbContextProvider dbProvider, CancellationToken cancellationToken) {
+		this.controllerState = controllerState;
 		this.databaseStorageActor = actorSystem.ActorOf(EventLogDatabaseStorageActor.Factory(new EventLogDatabaseStorageActor.Init(dbProvider, cancellationToken)), "EventLogDatabaseStorage");
 		this.dbProvider = dbProvider;
 		this.cancellationToken = cancellationToken;
@@ -22,8 +27,14 @@ sealed partial class EventLogManager {
 		databaseStorageActor.Tell(new EventLogDatabaseStorageActor.StoreEventCommand(eventGuid, utcTime, agentGuid, eventType, subjectId, extra));
 	}
 	
-	public async Task<ImmutableArray<EventLogItem>> GetMostRecentItems(int count) {
+	public async Task<Result<ImmutableArray<EventLogItem>, UserActionFailure>> GetMostRecentItems(LoggedInUser loggedInUser, int count) {
+		if (!loggedInUser.CheckPermission(Permission.ViewEvents)) {
+			return UserActionFailure.NotAuthorized;
+		}
+		
+		var accessibleAgentGuids = loggedInUser.FilterAccessibleAgentGuids(controllerState.AgentsByGuid.Keys.ToImmutableHashSet());
+		
 		await using var db = dbProvider.Lazy();
-		return await new EventLogRepository(db).GetMostRecentItems(count, cancellationToken);
+		return await new EventLogRepository(db).GetMostRecentItems(accessibleAgentGuids, count, cancellationToken);
 	}
 }

Controller/Phantom.Controller.Services/Instances/InstanceActor.cs

@@ -1,4 +1,5 @@
-using Phantom.Common.Data.Instance;
+using Phantom.Common.Data;
+using Phantom.Common.Data.Instance;
 using Phantom.Common.Data.Minecraft;
 using Phantom.Common.Data.Replies;
 using Phantom.Common.Data.Web.Instance;
@@ -25,6 +26,7 @@ sealed class InstanceActor : ReceiveActor<InstanceActor.ICommand> {
 	
 	private InstanceConfiguration configuration;
 	private IInstanceStatus status;
+	private InstancePlayerCounts? playerCounts;
 	private bool launchAutomatically;
 	
 	private readonly ActorRef<InstanceDatabaseStorageActor.ICommand> databaseStorageActor;
@@ -34,19 +36,20 @@ sealed class InstanceActor : ReceiveActor<InstanceActor.ICommand> {
 		this.agentConnection = init.AgentConnection;
 		this.cancellationToken = init.CancellationToken;
 		
-		(this.instanceGuid, this.configuration, this.status, this.launchAutomatically) = init.Instance;
+		(this.instanceGuid, this.configuration, this.status, this.playerCounts, this.launchAutomatically) = init.Instance;
 		
 		this.databaseStorageActor = Context.ActorOf(InstanceDatabaseStorageActor.Factory(new InstanceDatabaseStorageActor.Init(instanceGuid, init.DbProvider, init.CancellationToken)), "DatabaseStorage");
 		
 		Receive<SetStatusCommand>(SetStatus);
-		ReceiveAsyncAndReply<ConfigureInstanceCommand, InstanceActionResult<ConfigureInstanceResult>>(ConfigureInstance);
+		Receive<SetPlayerCountsCommand>(SetPlayerCounts);
-		ReceiveAsyncAndReply<LaunchInstanceCommand, InstanceActionResult<LaunchInstanceResult>>(LaunchInstance);
+		ReceiveAsyncAndReply<ConfigureInstanceCommand, Result<ConfigureInstanceResult, InstanceActionFailure>>(ConfigureInstance);
-		ReceiveAsyncAndReply<StopInstanceCommand, InstanceActionResult<StopInstanceResult>>(StopInstance);
+		ReceiveAsyncAndReply<LaunchInstanceCommand, Result<LaunchInstanceResult, InstanceActionFailure>>(LaunchInstance);
-		ReceiveAsyncAndReply<SendCommandToInstanceCommand, InstanceActionResult<SendCommandToInstanceResult>>(SendMinecraftCommand);
+		ReceiveAsyncAndReply<StopInstanceCommand, Result<StopInstanceResult, InstanceActionFailure>>(StopInstance);
+		ReceiveAsyncAndReply<SendCommandToInstanceCommand, Result<SendCommandToInstanceResult, InstanceActionFailure>>(SendMinecraftCommand);
 	}
 	
 	private void NotifyInstanceUpdated() {
-		agentActor.Tell(new AgentActor.ReceiveInstanceDataCommand(new Instance(instanceGuid, configuration, status, launchAutomatically)));
+		agentActor.Tell(new AgentActor.ReceiveInstanceDataCommand(new Instance(instanceGuid, configuration, status, playerCounts, launchAutomatically)));
 	}
 	
 	private void SetLaunchAutomatically(bool newValue) {
@@ -56,29 +59,41 @@ sealed class InstanceActor : ReceiveActor<InstanceActor.ICommand> {
 		}
 	}
 	
-	private async Task<InstanceActionResult<TReply>> SendInstanceActionMessage<TMessage, TReply>(TMessage message) where TMessage : IMessageToAgent, ICanReply<InstanceActionResult<TReply>> {
+	private async Task<Result<TReply, InstanceActionFailure>> SendInstanceActionMessage<TMessage, TReply>(TMessage message) where TMessage : IMessageToAgent, ICanReply<Result<TReply, InstanceActionFailure>> {
-		var reply = await agentConnection.Send<TMessage, InstanceActionResult<TReply>>(message, TimeSpan.FromSeconds(10), cancellationToken);
+		var reply = await agentConnection.Send<TMessage, Result<TReply, InstanceActionFailure>>(message, TimeSpan.FromSeconds(10), cancellationToken);
-		return reply.DidNotReplyIfNull();
+		return reply ?? InstanceActionFailure.AgentIsNotResponding;
 	}
 	
 	public interface ICommand {}
 	
 	public sealed record SetStatusCommand(IInstanceStatus Status) : ICommand;
 	
-	public sealed record ConfigureInstanceCommand(Guid AuditLogUserGuid, Guid InstanceGuid, InstanceConfiguration Configuration, InstanceLaunchProperties LaunchProperties, bool IsCreatingInstance) : ICommand, ICanReply<InstanceActionResult<ConfigureInstanceResult>>;
+	public sealed record SetPlayerCountsCommand(InstancePlayerCounts? PlayerCounts) : ICommand;
 	
-	public sealed record LaunchInstanceCommand(Guid AuditLogUserGuid) : ICommand, ICanReply<InstanceActionResult<LaunchInstanceResult>>;
+	public sealed record ConfigureInstanceCommand(Guid AuditLogUserGuid, Guid InstanceGuid, InstanceConfiguration Configuration, InstanceLaunchProperties LaunchProperties, bool IsCreatingInstance) : ICommand, ICanReply<Result<ConfigureInstanceResult, InstanceActionFailure>>;
 	
-	public sealed record StopInstanceCommand(Guid AuditLogUserGuid, MinecraftStopStrategy StopStrategy) : ICommand, ICanReply<InstanceActionResult<StopInstanceResult>>;
+	public sealed record LaunchInstanceCommand(Guid AuditLogUserGuid) : ICommand, ICanReply<Result<LaunchInstanceResult, InstanceActionFailure>>;
 	
-	public sealed record SendCommandToInstanceCommand(Guid AuditLogUserGuid, string Command) : ICommand, ICanReply<InstanceActionResult<SendCommandToInstanceResult>>;
+	public sealed record StopInstanceCommand(Guid AuditLogUserGuid, MinecraftStopStrategy StopStrategy) : ICommand, ICanReply<Result<StopInstanceResult, InstanceActionFailure>>;
+	
+	public sealed record SendCommandToInstanceCommand(Guid AuditLogUserGuid, string Command) : ICommand, ICanReply<Result<SendCommandToInstanceResult, InstanceActionFailure>>;
 	
 	private void SetStatus(SetStatusCommand command) {
 		status = command.Status;
+		
+		if (!status.IsRunning() && status != InstanceStatus.Offline /* Guard against temporary disconnects */) {
+			playerCounts = null;
+		}
+		
 		NotifyInstanceUpdated();
 	}
 	
-	private async Task<InstanceActionResult<ConfigureInstanceResult>> ConfigureInstance(ConfigureInstanceCommand command) {
+	private void SetPlayerCounts(SetPlayerCountsCommand command) {
+		playerCounts = command.PlayerCounts;
+		NotifyInstanceUpdated();
+	}
+	
+	private async Task<Result<ConfigureInstanceResult, InstanceActionFailure>> ConfigureInstance(ConfigureInstanceCommand command) {
 		var message = new ConfigureInstanceMessage(command.InstanceGuid, command.Configuration, command.LaunchProperties);
 		var result = await SendInstanceActionMessage<ConfigureInstanceMessage, ConfigureInstanceResult>(message);
 		
@@ -98,7 +113,7 @@ sealed class InstanceActor : ReceiveActor<InstanceActor.ICommand> {
 		return result;
 	}
 	
-	private async Task<InstanceActionResult<LaunchInstanceResult>> LaunchInstance(LaunchInstanceCommand command) {
+	private async Task<Result<LaunchInstanceResult, InstanceActionFailure>> LaunchInstance(LaunchInstanceCommand command) {
 		var message = new LaunchInstanceMessage(instanceGuid);
 		var result = await SendInstanceActionMessage<LaunchInstanceMessage, LaunchInstanceResult>(message);
 		
@@ -110,7 +125,7 @@ sealed class InstanceActor : ReceiveActor<InstanceActor.ICommand> {
 		return result;
 	}
 	
-	private async Task<InstanceActionResult<StopInstanceResult>> StopInstance(StopInstanceCommand command) {
+	private async Task<Result<StopInstanceResult, InstanceActionFailure>> StopInstance(StopInstanceCommand command) {
 		var message = new StopInstanceMessage(instanceGuid, command.StopStrategy);
 		var result = await SendInstanceActionMessage<StopInstanceMessage, StopInstanceResult>(message);
 		
@@ -122,7 +137,7 @@ sealed class InstanceActor : ReceiveActor<InstanceActor.ICommand> {
 		return result;
 	}
 	
-	private async Task<InstanceActionResult<SendCommandToInstanceResult>> SendMinecraftCommand(SendCommandToInstanceCommand command) {
+	private async Task<Result<SendCommandToInstanceResult, InstanceActionFailure>> SendMinecraftCommand(SendCommandToInstanceCommand command) {
 		var message = new SendCommandToInstanceMessage(instanceGuid, command.Command);
 		var result = await SendInstanceActionMessage<SendCommandToInstanceMessage, SendCommandToInstanceResult>(message);
 		

Controller/Phantom.Controller.Services/Rpc/AgentMessageHandlerActor.cs

@@ -39,6 +39,7 @@ sealed class AgentMessageHandlerActor : ReceiveActor<IMessageToController> {
 		Receive<AdvertiseJavaRuntimesMessage>(HandleAdvertiseJavaRuntimes);
 		Receive<ReportAgentStatusMessage>(HandleReportAgentStatus);
 		Receive<ReportInstanceStatusMessage>(HandleReportInstanceStatus);
+		Receive<ReportInstancePlayerCountsMessage>(HandleReportInstancePlayerCounts);
 		Receive<ReportInstanceEventMessage>(HandleReportInstanceEvent);
 		Receive<InstanceOutputMessage>(HandleInstanceOutput);
 		Receive<ReplyMessage>(HandleReply);
@@ -74,6 +75,10 @@ sealed class AgentMessageHandlerActor : ReceiveActor<IMessageToController> {
 		agentManager.TellAgent(agentGuid, new AgentActor.UpdateInstanceStatusCommand(message.InstanceGuid, message.InstanceStatus));
 	}
 	
+	private void HandleReportInstancePlayerCounts(ReportInstancePlayerCountsMessage message) {
+		agentManager.TellAgent(agentGuid, new AgentActor.UpdateInstancePlayerCountsCommand(message.InstanceGuid, message.PlayerCounts));
+	}
+	
 	private void HandleReportInstanceEvent(ReportInstanceEventMessage message) {
 		message.Event.Accept(eventLogManager.CreateInstanceEventVisitor(message.EventGuid, message.UtcTime, agentGuid, message.InstanceGuid));
 	}

Controller/Phantom.Controller.Services/Rpc/WebMessageDataUpdateSenderActor.cs

@@ -30,22 +30,31 @@ sealed class WebMessageDataUpdateSenderActor : ReceiveActor<WebMessageDataUpdate
 		ReceiveAsync<RefreshAgentsCommand>(RefreshAgents);
 		ReceiveAsync<RefreshInstancesCommand>(RefreshInstances);
 		ReceiveAsync<ReceiveInstanceLogsCommand>(ReceiveInstanceLogs);
+		ReceiveAsync<RefreshUserSessionCommand>(RefreshUserSession);
 	}
 	
 	protected override void PreStart() {
 		controllerState.AgentsByGuidReceiver.Register(SelfTyped, static state => new RefreshAgentsCommand(state));
 		controllerState.InstancesByGuidReceiver.Register(SelfTyped, static state => new RefreshInstancesCommand(state));
 		
+		controllerState.UserUpdatedOrDeleted += OnUserUpdatedOrDeleted;
+		
 		instanceLogManager.LogsReceived += OnInstanceLogsReceived;
 	}
 	
 	protected override void PostStop() {
 		instanceLogManager.LogsReceived -= OnInstanceLogsReceived;
 		
+		controllerState.UserUpdatedOrDeleted -= OnUserUpdatedOrDeleted;
+		
 		controllerState.AgentsByGuidReceiver.Unregister(SelfTyped);
 		controllerState.InstancesByGuidReceiver.Unregister(SelfTyped);
 	}
 	
+	private void OnUserUpdatedOrDeleted(object? sender, Guid userGuid) {
+		selfCached.Tell(new RefreshUserSessionCommand(userGuid));
+	}
+	
 	private void OnInstanceLogsReceived(object? sender, InstanceLogManager.Event e) {
 		selfCached.Tell(new ReceiveInstanceLogsCommand(e.InstanceGuid, e.Lines));
 	}
@@ -58,6 +67,8 @@ sealed class WebMessageDataUpdateSenderActor : ReceiveActor<WebMessageDataUpdate
 	
 	private sealed record ReceiveInstanceLogsCommand(Guid InstanceGuid, ImmutableArray<string> Lines) : ICommand;
 	
+	private sealed record RefreshUserSessionCommand(Guid UserGuid) : ICommand;
+	
 	private Task RefreshAgents(RefreshAgentsCommand command) {
 		return connection.Send(new RefreshAgentsMessage(command.Agents.Values.ToImmutableArray()));
 	}
@@ -69,4 +80,8 @@ sealed class WebMessageDataUpdateSenderActor : ReceiveActor<WebMessageDataUpdate
 	private Task ReceiveInstanceLogs(ReceiveInstanceLogsCommand command) {
 		return connection.Send(new InstanceOutputMessage(command.InstanceGuid, command.Lines));
 	}
+	
+	private Task RefreshUserSession(RefreshUserSessionCommand command) {
+		return connection.Send(new RefreshUserSessionMessage(command.UserGuid));
+	}
 }

Controller/Phantom.Controller.Services/Rpc/WebMessageHandlerActor.cs

@@ -1,4 +1,5 @@
 using System.Collections.Immutable;
+using Phantom.Common.Data;
 using Phantom.Common.Data.Java;
 using Phantom.Common.Data.Minecraft;
 using Phantom.Common.Data.Replies;
@@ -14,6 +15,7 @@ using Phantom.Controller.Services.Agents;
 using Phantom.Controller.Services.Events;
 using Phantom.Controller.Services.Instances;
 using Phantom.Controller.Services.Users;
+using Phantom.Controller.Services.Users.Sessions;
 using Phantom.Utils.Actor;
 using Phantom.Utils.Rpc.Runtime;
 
@@ -69,23 +71,24 @@ sealed class WebMessageHandlerActor : ReceiveActor<IMessageToController> {
 		
 		ReceiveAsync<RegisterWebMessage>(HandleRegisterWeb);
 		Receive<UnregisterWebMessage>(HandleUnregisterWeb);
-		ReceiveAndReplyLater<LogInMessage, LogInSuccess?>(HandleLogIn);
+		ReceiveAndReplyLater<LogInMessage, Optional<LogInSuccess>>(HandleLogIn);
 		Receive<LogOutMessage>(HandleLogOut);
+		ReceiveAndReply<GetAuthenticatedUser, Optional<AuthenticatedUserInfo>>(GetAuthenticatedUser);
 		ReceiveAndReplyLater<CreateOrUpdateAdministratorUserMessage, CreateOrUpdateAdministratorUserResult>(HandleCreateOrUpdateAdministratorUser);
-		ReceiveAndReplyLater<CreateUserMessage, CreateUserResult>(HandleCreateUser);
+		ReceiveAndReplyLater<CreateUserMessage, Result<CreateUserResult, UserActionFailure>>(HandleCreateUser);
 		ReceiveAndReplyLater<GetUsersMessage, ImmutableArray<UserInfo>>(HandleGetUsers);
 		ReceiveAndReplyLater<GetRolesMessage, ImmutableArray<RoleInfo>>(HandleGetRoles);
 		ReceiveAndReplyLater<GetUserRolesMessage, ImmutableDictionary<Guid, ImmutableArray<Guid>>>(HandleGetUserRoles);
-		ReceiveAndReplyLater<ChangeUserRolesMessage, ChangeUserRolesResult>(HandleChangeUserRoles);
+		ReceiveAndReplyLater<ChangeUserRolesMessage, Result<ChangeUserRolesResult, UserActionFailure>>(HandleChangeUserRoles);
-		ReceiveAndReplyLater<DeleteUserMessage, DeleteUserResult>(HandleDeleteUser);
+		ReceiveAndReplyLater<DeleteUserMessage, Result<DeleteUserResult, UserActionFailure>>(HandleDeleteUser);
-		ReceiveAndReplyLater<CreateOrUpdateInstanceMessage, InstanceActionResult<CreateOrUpdateInstanceResult>>(HandleCreateOrUpdateInstance);
+		ReceiveAndReplyLater<CreateOrUpdateInstanceMessage, Result<CreateOrUpdateInstanceResult, UserInstanceActionFailure>>(HandleCreateOrUpdateInstance);
-		ReceiveAndReplyLater<LaunchInstanceMessage, InstanceActionResult<LaunchInstanceResult>>(HandleLaunchInstance);
+		ReceiveAndReplyLater<LaunchInstanceMessage, Result<LaunchInstanceResult, UserInstanceActionFailure>>(HandleLaunchInstance);
-		ReceiveAndReplyLater<StopInstanceMessage, InstanceActionResult<StopInstanceResult>>(HandleStopInstance);
+		ReceiveAndReplyLater<StopInstanceMessage, Result<StopInstanceResult, UserInstanceActionFailure>>(HandleStopInstance);
-		ReceiveAndReplyLater<SendCommandToInstanceMessage, InstanceActionResult<SendCommandToInstanceResult>>(HandleSendCommandToInstance);
+		ReceiveAndReplyLater<SendCommandToInstanceMessage, Result<SendCommandToInstanceResult, UserInstanceActionFailure>>(HandleSendCommandToInstance);
 		ReceiveAndReplyLater<GetMinecraftVersionsMessage, ImmutableArray<MinecraftVersion>>(HandleGetMinecraftVersions);
 		ReceiveAndReply<GetAgentJavaRuntimesMessage, ImmutableDictionary<Guid, ImmutableArray<TaggedJavaRuntime>>>(HandleGetAgentJavaRuntimes);
-		ReceiveAndReplyLater<GetAuditLogMessage, ImmutableArray<AuditLogItem>>(HandleGetAuditLog);
+		ReceiveAndReplyLater<GetAuditLogMessage, Result<ImmutableArray<AuditLogItem>, UserActionFailure>>(HandleGetAuditLog);
-		ReceiveAndReplyLater<GetEventLogMessage, ImmutableArray<EventLogItem>>(HandleGetEventLog);
+		ReceiveAndReplyLater<GetEventLogMessage, Result<ImmutableArray<EventLogItem>, UserActionFailure>>(HandleGetEventLog);
 		Receive<ReplyMessage>(HandleReply);
 	}
 	
@@ -97,7 +100,7 @@ sealed class WebMessageHandlerActor : ReceiveActor<IMessageToController> {
 		connection.Close();
 	}
 	
-	private Task<LogInSuccess?> HandleLogIn(LogInMessage message) {
+	private Task<Optional<LogInSuccess>> HandleLogIn(LogInMessage message) {
 		return userLoginManager.LogIn(message.Username, message.Password);
 	}
 	
@@ -105,12 +108,16 @@ sealed class WebMessageHandlerActor : ReceiveActor<IMessageToController> {
 		_ = userLoginManager.LogOut(message.UserGuid, message.SessionToken);
 	}
 	
+	private Optional<AuthenticatedUserInfo> GetAuthenticatedUser(GetAuthenticatedUser message) {
+		return userLoginManager.GetAuthenticatedUser(message.UserGuid, message.AuthToken);
+	}
+	
 	private Task<CreateOrUpdateAdministratorUserResult> HandleCreateOrUpdateAdministratorUser(CreateOrUpdateAdministratorUserMessage message) {
 		return userManager.CreateOrUpdateAdministrator(message.Username, message.Password);
 	}
 	
-	private Task<CreateUserResult> HandleCreateUser(CreateUserMessage message) {
+	private Task<Result<CreateUserResult, UserActionFailure>> HandleCreateUser(CreateUserMessage message) {
-		return userManager.Create(message.LoggedInUserGuid, message.Username, message.Password);
+		return userManager.Create(userLoginManager.GetLoggedInUser(message.AuthToken), message.Username, message.Password);
 	}
 	
 	private Task<ImmutableArray<UserInfo>> HandleGetUsers(GetUsersMessage message) {
@@ -125,28 +132,48 @@ sealed class WebMessageHandlerActor : ReceiveActor<IMessageToController> {
 		return userRoleManager.GetUserRoles(message.UserGuids);
 	}
 	
-	private Task<ChangeUserRolesResult> HandleChangeUserRoles(ChangeUserRolesMessage message) {
+	private Task<Result<ChangeUserRolesResult, UserActionFailure>> HandleChangeUserRoles(ChangeUserRolesMessage message) {
-		return userRoleManager.ChangeUserRoles(message.LoggedInUserGuid, message.SubjectUserGuid, message.AddToRoleGuids, message.RemoveFromRoleGuids);
+		return userRoleManager.ChangeUserRoles(userLoginManager.GetLoggedInUser(message.AuthToken), message.SubjectUserGuid, message.AddToRoleGuids, message.RemoveFromRoleGuids);
 	}
 	
-	private Task<DeleteUserResult> HandleDeleteUser(DeleteUserMessage message) {
+	private Task<Result<DeleteUserResult, UserActionFailure>> HandleDeleteUser(DeleteUserMessage message) {
-		return userManager.DeleteByGuid(message.LoggedInUserGuid, message.SubjectUserGuid);
+		return userManager.DeleteByGuid(userLoginManager.GetLoggedInUser(message.AuthToken), message.SubjectUserGuid);
 	}
 	
-	private Task<InstanceActionResult<CreateOrUpdateInstanceResult>> HandleCreateOrUpdateInstance(CreateOrUpdateInstanceMessage message) {
+	private Task<Result<CreateOrUpdateInstanceResult, UserInstanceActionFailure>> HandleCreateOrUpdateInstance(CreateOrUpdateInstanceMessage message) {
-		return agentManager.DoInstanceAction<AgentActor.CreateOrUpdateInstanceCommand, CreateOrUpdateInstanceResult>(message.Configuration.AgentGuid, new AgentActor.CreateOrUpdateInstanceCommand(message.LoggedInUserGuid, message.InstanceGuid, message.Configuration));
+		return agentManager.DoInstanceAction<AgentActor.CreateOrUpdateInstanceCommand, CreateOrUpdateInstanceResult>(
+			Permission.CreateInstances,
+			message.AuthToken,
+			message.Configuration.AgentGuid,
+			loggedInUserGuid => new AgentActor.CreateOrUpdateInstanceCommand(loggedInUserGuid, message.InstanceGuid, message.Configuration)
+		);
 	}
 	
-	private Task<InstanceActionResult<LaunchInstanceResult>> HandleLaunchInstance(LaunchInstanceMessage message) {
+	private Task<Result<LaunchInstanceResult, UserInstanceActionFailure>> HandleLaunchInstance(LaunchInstanceMessage message) {
-		return agentManager.DoInstanceAction<AgentActor.LaunchInstanceCommand, LaunchInstanceResult>(message.AgentGuid, new AgentActor.LaunchInstanceCommand(message.InstanceGuid, message.LoggedInUserGuid));
+		return agentManager.DoInstanceAction<AgentActor.LaunchInstanceCommand, LaunchInstanceResult>(
+			Permission.ControlInstances,
+			message.AuthToken,
+			message.AgentGuid,
+			loggedInUserGuid => new AgentActor.LaunchInstanceCommand(loggedInUserGuid, message.InstanceGuid)
+		);
 	}
 	
-	private Task<InstanceActionResult<StopInstanceResult>> HandleStopInstance(StopInstanceMessage message) {
+	private Task<Result<StopInstanceResult, UserInstanceActionFailure>> HandleStopInstance(StopInstanceMessage message) {
-		return agentManager.DoInstanceAction<AgentActor.StopInstanceCommand, StopInstanceResult>(message.AgentGuid, new AgentActor.StopInstanceCommand(message.InstanceGuid, message.LoggedInUserGuid, message.StopStrategy));
+		return agentManager.DoInstanceAction<AgentActor.StopInstanceCommand, StopInstanceResult>(
+			Permission.ControlInstances,
+			message.AuthToken,
+			message.AgentGuid,
+			loggedInUserGuid => new AgentActor.StopInstanceCommand(loggedInUserGuid, message.InstanceGuid, message.StopStrategy)
+		);
 	}
 	
-	private Task<InstanceActionResult<SendCommandToInstanceResult>> HandleSendCommandToInstance(SendCommandToInstanceMessage message) {
+	private Task<Result<SendCommandToInstanceResult, UserInstanceActionFailure>> HandleSendCommandToInstance(SendCommandToInstanceMessage message) {
-		return agentManager.DoInstanceAction<AgentActor.SendCommandToInstanceCommand, SendCommandToInstanceResult>(message.AgentGuid, new AgentActor.SendCommandToInstanceCommand(message.InstanceGuid, message.LoggedInUserGuid, message.Command));
+		return agentManager.DoInstanceAction<AgentActor.SendCommandToInstanceCommand, SendCommandToInstanceResult>(
+			Permission.ControlInstances,
+			message.AuthToken,
+			message.AgentGuid,
+			loggedInUserGuid => new AgentActor.SendCommandToInstanceCommand(loggedInUserGuid, message.InstanceGuid, message.Command)
+		);
 	}
 	
 	private Task<ImmutableArray<MinecraftVersion>> HandleGetMinecraftVersions(GetMinecraftVersionsMessage message) {
@@ -157,12 +184,12 @@ sealed class WebMessageHandlerActor : ReceiveActor<IMessageToController> {
 		return controllerState.AgentJavaRuntimesByGuid;
 	}
 	
-	private Task<ImmutableArray<AuditLogItem>> HandleGetAuditLog(GetAuditLogMessage message) {
+	private Task<Result<ImmutableArray<AuditLogItem>, UserActionFailure>> HandleGetAuditLog(GetAuditLogMessage message) {
-		return auditLogManager.GetMostRecentItems(message.Count);
+		return auditLogManager.GetMostRecentItems(userLoginManager.GetLoggedInUser(message.AuthToken), message.Count);
 	}
 	
-	private Task<ImmutableArray<EventLogItem>> HandleGetEventLog(GetEventLogMessage message) {
+	private Task<Result<ImmutableArray<EventLogItem>, UserActionFailure>> HandleGetEventLog(GetEventLogMessage message) {
-		return eventLogManager.GetMostRecentItems(message.Count);
+		return eventLogManager.GetMostRecentItems(userLoginManager.GetLoggedInUser(message.AuthToken), message.Count);
 	}
 	
 	private void HandleReply(ReplyMessage message) {

Controller/Phantom.Controller.Services/Rpc/WebRegistrationHandler.cs

@@ -7,6 +7,7 @@ using Phantom.Controller.Services.Agents;
 using Phantom.Controller.Services.Events;
 using Phantom.Controller.Services.Instances;
 using Phantom.Controller.Services.Users;
+using Phantom.Controller.Services.Users.Sessions;
 using Phantom.Utils.Actor;
 using Phantom.Utils.Logging;
 using Phantom.Utils.Rpc.Runtime;

Controller/Phantom.Controller.Services/Users/AuditLogManager.cs

@@ -1,7 +1,10 @@
 using System.Collections.Immutable;
+using Phantom.Common.Data;
 using Phantom.Common.Data.Web.AuditLog;
+using Phantom.Common.Data.Web.Users;
 using Phantom.Controller.Database;
 using Phantom.Controller.Database.Repositories;
+using Phantom.Controller.Services.Users.Sessions;
 
 namespace Phantom.Controller.Services.Users;
 
@@ -12,7 +15,11 @@ sealed class AuditLogManager {
 		this.dbProvider = dbProvider;
 	}
 	
-	public async Task<ImmutableArray<AuditLogItem>> GetMostRecentItems(int count) {
+	public async Task<Result<ImmutableArray<AuditLogItem>, UserActionFailure>> GetMostRecentItems(LoggedInUser loggedInUser, int count) {
+		if (!loggedInUser.CheckPermission(Permission.ViewAudit)) {
+			return UserActionFailure.NotAuthorized;
+		}
+		
 		await using var db = dbProvider.Lazy();
 		return await new AuditLogRepository(db).GetMostRecentItems(count, CancellationToken.None);
 	}

Controller/Phantom.Controller.Services/Users/PermissionManager.cs

@@ -36,34 +36,6 @@ sealed class PermissionManager {
 		}
 	}
 	
-	public async Task<PermissionSet> FetchPermissionsForAllUsers(Guid userId) {
-		await using var ctx = dbProvider.Eager();
-		
-		var userPermissions = ctx.UserPermissions
-		                         .Where(up => up.UserGuid == userId)
-		                         .Select(static up => up.PermissionId);
-		
-		var rolePermissions = ctx.UserRoles
-		                         .Where(ur => ur.UserGuid == userId)
-		                         .Join(ctx.RolePermissions, static ur => ur.RoleGuid, static rp => rp.RoleGuid, static (ur, rp) => rp.PermissionId);
-		
-		return new PermissionSet(await userPermissions.Union(rolePermissions).AsAsyncEnumerable().ToImmutableSetAsync());
-	}
-	
-	public async Task<PermissionSet> FetchPermissionsForUserId(Guid userId) {
-		await using var ctx = dbProvider.Eager();
-		
-		var userPermissions = ctx.UserPermissions
-		                         .Where(up => up.UserGuid == userId)
-		                         .Select(static up => up.PermissionId);
-		
-		var rolePermissions = ctx.UserRoles
-		                         .Where(ur => ur.UserGuid == userId)
-		                         .Join(ctx.RolePermissions, static ur => ur.RoleGuid, static rp => rp.RoleGuid, static (ur, rp) => rp.PermissionId);
-		
-		return new PermissionSet(await userPermissions.Union(rolePermissions).AsAsyncEnumerable().ToImmutableSetAsync());
-	}
-
 	public static ImmutableArray<string> GetMissingPermissionsOrdered(IEnumerable<Permission> allPermissions, ImmutableHashSet<string> existingPermissionIds) {
 		return allPermissions.Select(static permission => permission.Id).Except(existingPermissionIds).Order().ToImmutableArray();
 	}

Controller/Phantom.Controller.Services/Users/Sessions/AuthenticatedUserCache.cs

@@ -0,0 +1,29 @@
+using System.Collections.Concurrent;
+using Phantom.Common.Data.Web.Users;
+using Phantom.Controller.Database;
+using Phantom.Controller.Database.Entities;
+using Phantom.Controller.Database.Repositories;
+
+namespace Phantom.Controller.Services.Users.Sessions;
+
+sealed class AuthenticatedUserCache {
+	private readonly ConcurrentDictionary<Guid, AuthenticatedUserInfo> authenticatedUsersByGuid = new ();
+	
+	public bool TryGet(Guid userGuid, out AuthenticatedUserInfo? userInfo) {
+		return authenticatedUsersByGuid.TryGetValue(userGuid, out userInfo);
+	}
+	
+	public async Task<AuthenticatedUserInfo?> Update(UserEntity user, ILazyDbContext db) {
+		var permissionRepository = new PermissionRepository(db);
+		var userPermissions = await permissionRepository.GetAllUserPermissions(user);
+		var userManagedAgentGuids = await permissionRepository.GetManagedAgentGuids(user);
+		
+		var userGuid = user.UserGuid;
+		var userInfo = new AuthenticatedUserInfo(userGuid, user.Name, userPermissions, userManagedAgentGuids);
+		return authenticatedUsersByGuid[userGuid] = userInfo;
+	}
+	
+	public void Remove(Guid userGuid) {
+		authenticatedUsersByGuid.Remove(userGuid, out _);
+	}
+}

Controller/Phantom.Controller.Services/Users/Sessions/LoggedInUser.cs

@@ -0,0 +1,20 @@
+using System.Collections.Immutable;
+using Phantom.Common.Data.Web.Users;
+
+namespace Phantom.Controller.Services.Users.Sessions;
+
+readonly record struct LoggedInUser(AuthenticatedUserInfo? AuthenticatedUserInfo) {
+	public Guid? Guid => AuthenticatedUserInfo?.Guid;
+	
+	public bool CheckPermission(Permission permission) {
+		return AuthenticatedUserInfo is {} info && info.CheckPermission(permission);
+	}
+	
+	public bool HasAccessToAgent(Guid agentGuid) {
+		return AuthenticatedUserInfo is {} info && info.HasAccessToAgent(agentGuid);
+	}
+	
+	public ImmutableHashSet<Guid> FilterAccessibleAgentGuids(ImmutableHashSet<Guid> agentGuids) {
+		return AuthenticatedUserInfo is {} info ? info.FilterAccessibleAgentGuids(agentGuids) : ImmutableHashSet<Guid>.Empty;
+	}
+}

Controller/Phantom.Controller.Services/Users/Sessions/UserLoginManager.cs

@@ -0,0 +1,140 @@
+using System.Collections.Immutable;
+using System.Security.Cryptography;
+using Phantom.Common.Data;
+using Phantom.Common.Data.Web.Users;
+using Phantom.Controller.Database;
+using Phantom.Controller.Database.Repositories;
+
+namespace Phantom.Controller.Services.Users.Sessions;
+
+sealed class UserLoginManager {
+	private const int SessionIdBytes = 20;
+	
+	private readonly AuthenticatedUserCache authenticatedUserCache;
+	private readonly UserManager userManager;
+	private readonly IDbContextProvider dbProvider;
+	
+	private readonly UserSessionBucket[] sessionBuckets = new UserSessionBucket[256];
+	
+	public UserLoginManager(AuthenticatedUserCache authenticatedUserCache, UserManager userManager, IDbContextProvider dbProvider) {
+		this.authenticatedUserCache = authenticatedUserCache;
+		this.userManager = userManager;
+		this.dbProvider = dbProvider;
+		
+		for (int i = 0; i < sessionBuckets.GetLength(0); i++) {
+			sessionBuckets[i] = new UserSessionBucket();
+		}
+	}
+	
+	private UserSessionBucket GetSessionBucket(ImmutableArray<byte> token) {
+		return sessionBuckets[token[0]];
+	}
+	
+	public async Task<Optional<LogInSuccess>> LogIn(string username, string password) {
+		Guid userGuid;
+		AuthenticatedUserInfo? authenticatedUserInfo;
+		
+		await using (var db = dbProvider.Lazy()) {
+			var userRepository = new UserRepository(db);
+			
+			var user = await userRepository.GetByName(username);
+			if (user == null || !UserPasswords.Verify(password, user.PasswordHash)) {
+				return default;
+			}
+			
+			authenticatedUserInfo = await authenticatedUserCache.Update(user, db);
+			if (authenticatedUserInfo == null) {
+				return default;
+			}
+			
+			userGuid = user.UserGuid;
+			
+			var auditLogWriter = new AuditLogRepository(db).Writer(userGuid);
+			auditLogWriter.UserLoggedIn(user);
+			
+			await db.Ctx.SaveChangesAsync();
+		}
+		
+		var authToken = ImmutableArray.Create(RandomNumberGenerator.GetBytes(SessionIdBytes));
+		GetSessionBucket(authToken).Add(userGuid, authToken);
+		
+		return new LogInSuccess(authenticatedUserInfo, authToken);
+	}
+	
+	public async Task LogOut(Guid userGuid, ImmutableArray<byte> authToken) {
+		if (!GetSessionBucket(authToken).Remove(userGuid, authToken)) {
+			return;
+		}
+		
+		await using var db = dbProvider.Lazy();
+		
+		var auditLogWriter = new AuditLogRepository(db).Writer(userGuid);
+		auditLogWriter.UserLoggedOut(userGuid);
+		
+		await db.Ctx.SaveChangesAsync();
+	}
+	
+	public LoggedInUser GetLoggedInUser(ImmutableArray<byte> authToken) {
+		var userGuid = GetSessionBucket(authToken).FindUserGuid(authToken);
+		return userGuid != null && authenticatedUserCache.TryGet(userGuid.Value, out var userInfo) ? new LoggedInUser(userInfo) : default;
+	}
+	
+	public AuthenticatedUserInfo? GetAuthenticatedUser(Guid userGuid, ImmutableArray<byte> authToken) {
+		return authenticatedUserCache.TryGet(userGuid, out var userInfo) && GetSessionBucket(authToken).Contains(userGuid, authToken) ? userInfo : null;
+	}
+	
+	private sealed class UserSessionBucket {
+		private ImmutableList<UserSession> sessions = ImmutableList<UserSession>.Empty;
+		
+		public void Add(Guid userGuid, ImmutableArray<byte> authToken) {
+			lock (this) {
+				var session = new UserSession(userGuid, authToken);
+				if (!sessions.Contains(session)) {
+					sessions = sessions.Add(session);
+				}
+			}
+		}
+		
+		public bool Contains(Guid userGuid, ImmutableArray<byte> authToken) {
+			lock (this) {
+				return sessions.Contains(new UserSession(userGuid, authToken));
+			}
+		}
+		
+		public Guid? FindUserGuid(ImmutableArray<byte> authToken) {
+			lock (this) {
+				return sessions.Find(session => session.AuthTokenEquals(authToken))?.UserGuid;
+			}
+		}
+		
+		public bool Remove(Guid userGuid, ImmutableArray<byte> authToken) {
+			lock (this) {
+				int index = sessions.IndexOf(new UserSession(userGuid, authToken));
+				if (index == -1) {
+					return false;
+				}
+				
+				sessions = sessions.RemoveAt(index);
+				return true;
+			}
+		}
+	}
+	
+	private sealed record UserSession(Guid UserGuid, ImmutableArray<byte> AuthToken) {
+		public bool AuthTokenEquals(ImmutableArray<byte> other) {
+			return CryptographicOperations.FixedTimeEquals(AuthToken.AsSpan(), other.AsSpan());
+		}
+		
+		public bool Equals(UserSession? other) {
+			if (ReferenceEquals(null, other)) {
+				return false;
+			}
+			
+			return UserGuid.Equals(other.UserGuid) && AuthTokenEquals(other.AuthToken);
+		}
+		
+		public override int GetHashCode() {
+			throw new NotImplementedException();
+		}
+	}
+}

Controller/Phantom.Controller.Services/Users/UserLoginManager.cs

@@ -1,64 +0,0 @@
-using System.Collections.Concurrent;
-using System.Collections.Immutable;
-using System.Security.Cryptography;
-using Phantom.Common.Data.Web.Users;
-using Phantom.Controller.Database;
-using Phantom.Controller.Database.Repositories;
-
-namespace Phantom.Controller.Services.Users; 
-
-sealed class UserLoginManager {
-	private const int SessionIdBytes = 20;
-	private readonly ConcurrentDictionary<Guid, List<ImmutableArray<byte>>> sessionTokensByUserGuid = new ();
-	
-	private readonly UserManager userManager;
-	private readonly PermissionManager permissionManager;
-	private readonly IDbContextProvider dbProvider;
-	
-	public UserLoginManager(UserManager userManager, PermissionManager permissionManager, IDbContextProvider dbProvider) {
-		this.userManager = userManager;
-		this.permissionManager = permissionManager;
-		this.dbProvider = dbProvider;
-	}
-
-	public async Task<LogInSuccess?> LogIn(string username, string password) {
-		var user = await userManager.GetAuthenticated(username, password);
-		if (user == null) {
-			return null;
-		}
-
-		var token = ImmutableArray.Create(RandomNumberGenerator.GetBytes(SessionIdBytes));
-		var sessionTokens = sessionTokensByUserGuid.GetOrAdd(user.UserGuid, static _ => new List<ImmutableArray<byte>>());
-		lock (sessionTokens) {
-			sessionTokens.Add(token);
-		}
-
-		await using (var db = dbProvider.Lazy()) {
-			var auditLogWriter = new AuditLogRepository(db).Writer(user.UserGuid);
-			auditLogWriter.UserLoggedIn(user);
-			
-			await db.Ctx.SaveChangesAsync();
-		}
-
-		return new LogInSuccess(user.UserGuid, await permissionManager.FetchPermissionsForUserId(user.UserGuid), token);
-	}
-
-	public async Task LogOut(Guid userGuid, ImmutableArray<byte> sessionToken) {
-		if (!sessionTokensByUserGuid.TryGetValue(userGuid, out var sessionTokens)) {
-			return;
-		}
-
-		lock (sessionTokens) {
-			if (sessionTokens.RemoveAll(token => token.SequenceEqual(sessionToken)) == 0) {
-				return;
-			}
-		}
-
-		await using var db = dbProvider.Lazy();
-		
-		var auditLogWriter = new AuditLogRepository(db).Writer(userGuid);
-		auditLogWriter.UserLoggedOut(userGuid);
-			
-		await db.Ctx.SaveChangesAsync();
-	}
-}

Controller/Phantom.Controller.Services/Users/UserManager.cs

@@ -1,8 +1,11 @@
 using System.Collections.Immutable;
+using Phantom.Common.Data;
 using Phantom.Common.Data.Web.Users;
+using Phantom.Common.Data.Web.Users.CreateOrUpdateAdministratorUserResults;
 using Phantom.Controller.Database;
 using Phantom.Controller.Database.Entities;
 using Phantom.Controller.Database.Repositories;
+using Phantom.Controller.Services.Users.Sessions;
 using Phantom.Utils.Logging;
 using Serilog;
 
@@ -11,9 +14,13 @@ namespace Phantom.Controller.Services.Users;
 sealed class UserManager {
 	private static readonly ILogger Logger = PhantomLogger.Create<UserManager>();
 	
+	private readonly AuthenticatedUserCache authenticatedUserCache;
+	private readonly ControllerState controllerState;
 	private readonly IDbContextProvider dbProvider;
 	
-	public UserManager(IDbContextProvider dbProvider) {
+	public UserManager(AuthenticatedUserCache authenticatedUserCache, ControllerState controllerState, IDbContextProvider dbProvider) {
+		this.authenticatedUserCache = authenticatedUserCache;
+		this.controllerState = controllerState;
 		this.dbProvider = dbProvider;
 	}
 	
@@ -50,13 +57,12 @@ sealed class UserManager {
 					wasCreated = true;
 				}
 				else {
-					return new Common.Data.Web.Users.CreateOrUpdateAdministratorUserResults.CreationFailed(result.Error);
+					return new CreationFailed(result.Error);
 				}
 			}
 			else {
-				var result = userRepository.SetUserPassword(user, password);
+				if (userRepository.SetUserPassword(user, password).TryGetError(out var error)) {
-				if (!result) {
+					return new UpdatingFailed(error);
-					return new Common.Data.Web.Users.CreateOrUpdateAdministratorUserResults.UpdatingFailed(result.Error);
 				}
 				
 				auditLogWriter.AdministratorUserModified(user);
@@ -65,7 +71,7 @@ sealed class UserManager {
 			
 			var role = await new RoleRepository(db).GetByGuid(Role.Administrator.Guid);
 			if (role == null) {
-				return new Common.Data.Web.Users.CreateOrUpdateAdministratorUserResults.AddingToRoleFailed();
+				return new AddingToRoleFailed();
 			}
 			
 			await new UserRoleRepository(db).Add(user, role);
@@ -79,17 +85,21 @@ sealed class UserManager {
 				Logger.Information("Updated administrator user \"{Username}\" (GUID {Guid}).", username, user.UserGuid);
 			}
 			
-			return new Common.Data.Web.Users.CreateOrUpdateAdministratorUserResults.Success(user.ToUserInfo());
+			return new Success(user.ToUserInfo());
 		} catch (Exception e) {
 			Logger.Error(e, "Could not create or update administrator user \"{Username}\".", username);
-			return new Common.Data.Web.Users.CreateOrUpdateAdministratorUserResults.UnknownError();
+			return new UnknownError();
 		}
 	}
 	
-	public async Task<CreateUserResult> Create(Guid loggedInUserGuid, string username, string password) {
+	public async Task<Result<CreateUserResult, UserActionFailure>> Create(LoggedInUser loggedInUser, string username, string password) {
+		if (!loggedInUser.CheckPermission(Permission.EditUsers)) {
+			return UserActionFailure.NotAuthorized;
+		}
+		
 		await using var db = dbProvider.Lazy();
 		var userRepository = new UserRepository(db);
-		var auditLogWriter = new AuditLogRepository(db).Writer(loggedInUserGuid);
+		var auditLogWriter = new AuditLogRepository(db).Writer(loggedInUser.Guid);
 		
 		try {
 			var result = await userRepository.CreateUser(username, password);
@@ -110,7 +120,11 @@ sealed class UserManager {
 		}
 	}
 	
-	public async Task<DeleteUserResult> DeleteByGuid(Guid loggedInUserGuid, Guid userGuid) {
+	public async Task<Result<DeleteUserResult, UserActionFailure>> DeleteByGuid(LoggedInUser loggedInUser, Guid userGuid) {
+		if (!loggedInUser.CheckPermission(Permission.EditUsers)) {
+			return UserActionFailure.NotAuthorized;
+		}
+		
 		await using var db = dbProvider.Lazy();
 		var userRepository = new UserRepository(db);
 		
@@ -119,12 +133,18 @@ sealed class UserManager {
 			return DeleteUserResult.NotFound;
 		}
 		
-		var auditLogWriter = new AuditLogRepository(db).Writer(loggedInUserGuid);
+		authenticatedUserCache.Remove(userGuid);
+		
+		var auditLogWriter = new AuditLogRepository(db).Writer(loggedInUser.Guid);
 		try {
 			userRepository.DeleteUser(user);
 			auditLogWriter.UserDeleted(user);
 			await db.Ctx.SaveChangesAsync();
 			
+			// In case the user logged in during deletion.
+			authenticatedUserCache.Remove(userGuid);
+			controllerState.UpdateOrDeleteUser(userGuid);
+			
 			Logger.Information("Deleted user \"{Username}\" (GUID {Guid}).", user.Name, user.UserGuid);
 			return DeleteUserResult.Deleted;
 		} catch (Exception e) {

Controller/Phantom.Controller.Services/Users/UserRoleManager.cs

@@ -1,7 +1,9 @@
 using System.Collections.Immutable;
+using Phantom.Common.Data;
 using Phantom.Common.Data.Web.Users;
 using Phantom.Controller.Database;
 using Phantom.Controller.Database.Repositories;
+using Phantom.Controller.Services.Users.Sessions;
 using Phantom.Utils.Logging;
 using Serilog;
 
@@ -10,9 +12,13 @@ namespace Phantom.Controller.Services.Users;
 sealed class UserRoleManager {
 	private static readonly ILogger Logger = PhantomLogger.Create<UserRoleManager>();
 	
+	private readonly AuthenticatedUserCache authenticatedUserCache;
+	private readonly ControllerState controllerState;
 	private readonly IDbContextProvider dbProvider;
 	
-	public UserRoleManager(IDbContextProvider dbProvider) {
+	public UserRoleManager(AuthenticatedUserCache authenticatedUserCache, ControllerState controllerState, IDbContextProvider dbProvider) {
+		this.authenticatedUserCache = authenticatedUserCache;
+		this.controllerState = controllerState;
 		this.dbProvider = dbProvider;
 	}
 	
@@ -21,7 +27,11 @@ sealed class UserRoleManager {
 		return await new UserRoleRepository(db).GetRoleGuidsByUserGuid(userGuids);
 	}
 	
-	public async Task<ChangeUserRolesResult> ChangeUserRoles(Guid loggedInUserGuid, Guid subjectUserGuid, ImmutableHashSet<Guid> addToRoleGuids, ImmutableHashSet<Guid> removeFromRoleGuids) {
+	public async Task<Result<ChangeUserRolesResult, UserActionFailure>> ChangeUserRoles(LoggedInUser loggedInUser, Guid subjectUserGuid, ImmutableHashSet<Guid> addToRoleGuids, ImmutableHashSet<Guid> removeFromRoleGuids) {
+		if (!loggedInUser.CheckPermission(Permission.EditUsers)) {
+			return UserActionFailure.NotAuthorized;
+		}
+		
 		await using var db = dbProvider.Lazy();
 		var userRepository = new UserRepository(db);
 		
@@ -32,7 +42,7 @@ sealed class UserRoleManager {
 		
 		var roleRepository = new RoleRepository(db);
 		var userRoleRepository = new UserRoleRepository(db);
-		var auditLogWriter = new AuditLogRepository(db).Writer(loggedInUserGuid);
+		var auditLogWriter = new AuditLogRepository(db).Writer(loggedInUser.Guid);
 		
 		var rolesByGuid = await roleRepository.GetByGuids(addToRoleGuids.Union(removeFromRoleGuids));
 		
@@ -62,6 +72,9 @@ sealed class UserRoleManager {
 			auditLogWriter.UserRolesChanged(user, addedToRoleNames, removedFromRoleNames);
 			await db.Ctx.SaveChangesAsync();
 			
+			await authenticatedUserCache.Update(user, db);
+			controllerState.UpdateOrDeleteUser(user.UserGuid);
+			
 			Logger.Information("Changed roles for user \"{Username}\" (GUID {Guid}).", user.Name, user.UserGuid);
 			return new ChangeUserRolesResult(addedToRoleGuids.ToImmutable(), removedFromRoleGuids.ToImmutable());
 		} catch (Exception e) {

Directory.Build.props

@@ -1,8 +1,8 @@
 <Project>
   
   <PropertyGroup>
-    <TargetFramework>net8.0</TargetFramework>
+    <TargetFramework>net9.0</TargetFramework>
-    <LangVersion>11</LangVersion>
+    <LangVersion>13</LangVersion>
   </PropertyGroup>
   
   <PropertyGroup>

Dockerfile

@@ -1,7 +1,7 @@
 # +---------------+
 # | Prepare build |
 # +---------------+
-FROM --platform=$BUILDPLATFORM mcr.microsoft.com/dotnet/nightly/sdk:8.0 AS phantom-builder
+FROM --platform=$BUILDPLATFORM mcr.microsoft.com/dotnet/nightly/sdk:9.0 AS phantom-builder
 ARG TARGETARCH
 
 ADD . /app
@@ -19,7 +19,7 @@ RUN find .artifacts/publish/*/* -maxdepth 0 -execdir mv '{}' 'release' \;
 # +---------------------+
 # | Phantom Agent image |
 # +---------------------+
-FROM mcr.microsoft.com/dotnet/nightly/runtime:8.0 AS phantom-agent
+FROM mcr.microsoft.com/dotnet/nightly/runtime:9.0 AS phantom-agent
 
 RUN mkdir /data && chmod 777 /data
 WORKDIR /data
@@ -27,7 +27,7 @@ WORKDIR /data
 COPY --from=eclipse-temurin:8-jre  /opt/java/openjdk /opt/java/8
 COPY --from=eclipse-temurin:16-jdk /opt/java/openjdk /opt/java/16
 COPY --from=eclipse-temurin:17-jre /opt/java/openjdk /opt/java/17
-COPY --from=eclipse-temurin:20-jre /opt/java/openjdk /opt/java/20
+COPY --from=eclipse-temurin:21-jre /opt/java/openjdk /opt/java/21
 
 ARG DEBIAN_FRONTEND=noninteractive
 
@@ -46,7 +46,7 @@ ENTRYPOINT ["dotnet", "/app/Phantom.Agent.dll"]
 # +--------------------------+
 # | Phantom Controller image |
 # +--------------------------+
-FROM mcr.microsoft.com/dotnet/nightly/runtime:8.0 AS phantom-controller
+FROM mcr.microsoft.com/dotnet/nightly/runtime:9.0 AS phantom-controller
 
 RUN mkdir /data && chmod 777 /data
 WORKDIR /data
@@ -59,7 +59,7 @@ ENTRYPOINT ["dotnet", "/app/Phantom.Controller.dll"]
 # +-------------------+
 # | Phantom Web image |
 # +-------------------+
-FROM mcr.microsoft.com/dotnet/nightly/aspnet:8.0 AS phantom-web
+FROM mcr.microsoft.com/dotnet/nightly/aspnet:9.0 AS phantom-web
 
 RUN mkdir /data && chmod 777 /data
 WORKDIR /data

Utils/Phantom.Utils.Actor/Tasks/TaskExtensions.cs

@@ -17,6 +17,10 @@ public static class TaskExtensions {
 		return task.ContinueOnActor(result => mapper(result, arg));
 	}
 	
+	public static Task<TResult> ContinueOnActor<TSource, TArg1, TArg2, TResult>(this Task<TSource> task, Func<TSource, TArg1, TArg2, TResult> mapper, TArg1 arg1, TArg2 arg2) {
+		return task.ContinueOnActor(result => mapper(result, arg1, arg2));
+	}
+	
 	private static Task<TResult> MapResult<TSource, TResult>(Task<TSource> task, Func<TSource, TResult> mapper, TaskCompletionSource<TResult> completionSource) {
 		if (task.IsFaulted) {
 			completionSource.SetException(task.Exception.InnerExceptions);

Utils/Phantom.Utils.Tests/Collections/RingBufferTests.cs

@@ -59,25 +59,25 @@ public sealed class RingBufferTests {
 		[Test]
 		public void AddOneItemAndEnumerateOne() {
 			var buffer = PrepareRingBuffer(10, "a");
-			Assert.That(buffer.EnumerateLast(1), Is.EquivalentTo(new [] { "a" }));
+			Assert.That(buffer.EnumerateLast(1), Is.EquivalentTo(new[] { "a" }));
 		}
 		
 		[Test]
 		public void AddOneItemAndEnumerateMaxValue() {
 			var buffer = PrepareRingBuffer(10, "a");
-			Assert.That(buffer.EnumerateLast(uint.MaxValue), Is.EquivalentTo(new [] { "a" }));
+			Assert.That(buffer.EnumerateLast(uint.MaxValue), Is.EquivalentTo(new[] { "a" }));
 		}
 		
 		[Test]
 		public void AddMultipleItemsWithinCapacityAndEnumerateFewer() {
 			var buffer = PrepareRingBuffer(10, "a", "b", "c");
-			Assert.That(buffer.EnumerateLast(2), Is.EquivalentTo(new [] { "b", "c" }));
+			Assert.That(buffer.EnumerateLast(2), Is.EquivalentTo(new[] { "b", "c" }));
 		}
 		
 		[Test]
 		public void AddMultipleItemsWithinCapacityAndEnumerateMaxValue() {
 			var buffer = PrepareRingBuffer(10, "a", "b", "c");
-			Assert.That(buffer.EnumerateLast(uint.MaxValue), Is.EquivalentTo(new [] { "a", "b", "c" }));
+			Assert.That(buffer.EnumerateLast(uint.MaxValue), Is.EquivalentTo(new[] { "a", "b", "c" }));
 		}
 		
 		[TestCase(3)]
@@ -85,12 +85,12 @@ public sealed class RingBufferTests {
 		[TestCase(5)]
 		public void AddMultipleItemsOverflowingCapacityAndEnumerateFewer(int capacity) {
 			var buffer = PrepareRingBuffer(capacity, "a", "b", "c", "d", "e", "f");
-			Assert.That(buffer.EnumerateLast(2), Is.EquivalentTo(new [] { "e", "f" }));
+			Assert.That(buffer.EnumerateLast(2), Is.EquivalentTo(new[] { "e", "f" }));
 		}
 		
-		[TestCase(3, ExpectedResult = new [] { "d", "e", "f" })]
+		[TestCase(3, ExpectedResult = new[] { "d", "e", "f" })]
-		[TestCase(4, ExpectedResult = new [] { "c", "d", "e", "f" })]
+		[TestCase(4, ExpectedResult = new[] { "c", "d", "e", "f" })]
-		[TestCase(5, ExpectedResult = new [] { "b", "c", "d", "e", "f" })]
+		[TestCase(5, ExpectedResult = new[] { "b", "c", "d", "e", "f" })]
 		public string[] AddMultipleItemsOverflowingCapacityAndEnumerateMaxValue(int capacity) {
 			var buffer = PrepareRingBuffer(capacity, "a", "b", "c", "d", "e", "f");
 			return buffer.EnumerateLast(uint.MaxValue).ToArray();

Utils/Phantom.Utils/Collections/EnumerableExtensions.cs

@@ -13,6 +13,27 @@ public static class EnumerableExtensions {
 		return builder.ToImmutable();
 	}
 	
+	public static async Task<ImmutableArray<TSource>> ToImmutableArrayCatchingExceptionsAsync<TSource>(this IAsyncEnumerable<TSource> source, Action<Exception> onException, CancellationToken cancellationToken = default) {
+		var builder = ImmutableArray.CreateBuilder<TSource>();
+		
+		await using (var enumerator = source.GetAsyncEnumerator(cancellationToken)) {
+			while (true) {
+				try {
+					if (!await enumerator.MoveNextAsync()) {
+						break;
+					}
+				} catch (Exception e) {
+					onException(e);
+					continue;
+				}
+				
+				builder.Add(enumerator.Current);
+			}
+		}
+		
+		return builder.ToImmutable();
+	}
+	
 	public static async Task<ImmutableHashSet<TSource>> ToImmutableSetAsync<TSource>(this IAsyncEnumerable<TSource> source, CancellationToken cancellationToken = default) {
 		var builder = ImmutableHashSet.CreateBuilder<TSource>();
 		

Utils/Phantom.Utils/Result/Err.cs

@@ -0,0 +1,3 @@
+namespace Phantom.Utils.Result;
+
+public sealed record Err<T>(T Error) : Result;

Utils/Phantom.Utils/Result/Ok.cs

@@ -0,0 +1,3 @@
+namespace Phantom.Utils.Result;
+
+public sealed record Ok<T>(T Value) : Result;

Utils/Phantom.Utils/Result/Result.cs

@@ -0,0 +1,5 @@
+namespace Phantom.Utils.Result;
+
+public abstract record Result {
+	private protected Result() {}
+}

Utils/Phantom.Utils/Tasks/Result.cs

@@ -1,69 +0,0 @@
-using System.Diagnostics.CodeAnalysis;
-
-namespace Phantom.Utils.Tasks;
-
-public abstract record Result<TValue, TError> {
-	private Result() {}
-
-	public abstract TValue Value { get; init; }
-	public abstract TError Error { get; init; }
-
-	public static implicit operator Result<TValue, TError>(TValue value) {
-		return new Ok(value);
-	}
-	
-	public static implicit operator Result<TValue, TError>(TError error) {
-		return new Fail(error);
-	}
-
-	public static implicit operator bool(Result<TValue, TError> result) {
-		return result is Ok;
-	}
-	
-	public sealed record Ok(TValue Value) : Result<TValue, TError> {
-		public override TError Error {
-			get => throw new InvalidOperationException("Attempted to get error from Ok result.");
-			init {}
-		}
-	}
-
-	public sealed record Fail(TError Error) : Result<TValue, TError> {
-		public override TValue Value {
-			get => throw new InvalidOperationException("Attempted to get value from Fail result.");
-			init {}
-		}
-	}
-}
-
-public abstract record Result<TError> {
-	private Result() {}
-	
-	public abstract TError Error { get; init; }
-
-	public static implicit operator Result<TError>(TError error) {
-		return new Fail(error);
-	}
-
-	public static implicit operator Result<TError>([SuppressMessage("ReSharper", "UnusedParameter.Global")] Result.OkType _) {
-		return new Ok();
-	}
-	
-	public static implicit operator bool(Result<TError> result) {
-		return result is Ok;
-	}
-	
-	public sealed record Ok : Result<TError> {
-		public override TError Error {
-			get => throw new InvalidOperationException("Attempted to get error from Ok result.");
-			init {}
-		}
-	}
-	
-	public sealed record Fail(TError Error) : Result<TError>;
-}
-
-public static class Result {
-	public static OkType Ok { get; }  = new ();
-
-	public readonly record struct OkType;
-}

Web/Phantom.Web.Components/Forms/FormSubmitError.razor

@@ -1,6 +1,6 @@
 @using Phantom.Web.Components.Utils
 @if (messageLines.Length > 0) {
-  <div class="form-submit-errors text-danger">
+  <div class="form-submit-errors text-danger" role="alert">
     @for (int i = 0; i < messageLines.Length; i++) {
       @messageLines[i]
       if (i < messageLines.Length - 1) {

Web/Phantom.Web.Components/PhantomComponent.cs

@@ -2,9 +2,8 @@
 using Microsoft.AspNetCore.Components.Authorization;
 using Phantom.Common.Data.Web.Users;
 using Phantom.Utils.Logging;
-using Phantom.Web.Services.Authorization;
+using Phantom.Web.Services.Authentication;
 using ILogger = Serilog.ILogger;
-using UserInfo = Phantom.Web.Services.Authentication.UserInfo;
 
 namespace Phantom.Web.Components;
 
@@ -14,21 +13,18 @@ public abstract class PhantomComponent : ComponentBase, IDisposable {
 	[CascadingParameter]
 	public Task<AuthenticationState> AuthenticationStateTask { get; set; } = null!;
 	
-	[Inject]
-	public PermissionManager PermissionManager { get; set; } = null!;
-
 	private readonly CancellationTokenSource cancellationTokenSource = new ();
 	
 	protected CancellationToken CancellationToken => cancellationTokenSource.Token;
 	
-	protected async Task<Guid?> GetUserGuid() {
+	protected async Task<AuthenticatedUser?> GetAuthenticatedUser() {
 		var authenticationState = await AuthenticationStateTask;
-		return UserInfo.TryGetGuid(authenticationState.User);
+		return authenticationState.GetAuthenticatedUser();
 	}
 	
 	protected async Task<bool> CheckPermission(Permission permission) {
 		var authenticationState = await AuthenticationStateTask;
-		return PermissionManager.CheckPermission(authenticationState.User, permission);
+		return authenticationState.CheckPermission(permission);
 	}
 	
 	protected void InvokeAsyncChecked(Func<Task> task) {

Web/Phantom.Web.Components/Utils/FormCustomValidationAttribute.cs

@@ -9,12 +9,12 @@ public abstract class FormCustomValidationAttribute<TModel, TValue> : Validation
 	
 	protected sealed override ValidationResult? IsValid(object? value, ValidationContext validationContext) {
 		if (value is not TValue typedValue) {
-			return new ValidationResult(null, new [] { FieldName });
+			return new ValidationResult(null, new[] { FieldName });
 		}
 		
 		var model = (TModel) validationContext.ObjectInstance;
 		var result = Validate(model, typedValue);
-		return result == ValidationResult.Success ? result : new ValidationResult(result?.ErrorMessage, new [] { FieldName });
+		return result == ValidationResult.Success ? result : new ValidationResult(result?.ErrorMessage, new[] { FieldName });
 	}
 	
 	protected abstract string FieldName { get; }

Web/Phantom.Web.Components/Utils/FormValidationAttribute.cs

@@ -9,7 +9,7 @@ public abstract class FormValidationAttribute<TModel, TValue> : ValidationAttrib
 	
 	protected sealed override ValidationResult? IsValid(object? value, ValidationContext validationContext) {
 		var model = (TModel) validationContext.ObjectInstance;
-		return value is TValue typedValue && IsValid(model, typedValue) ? ValidationResult.Success : new ValidationResult(null, new [] { FieldName });
+		return value is TValue typedValue && IsValid(model, typedValue) ? ValidationResult.Success : new ValidationResult(null, new[] { FieldName });
 	}
 	
 	protected abstract string FieldName { get; }

Web/Phantom.Web.Services/Agents/AgentManager.cs

@@ -2,6 +2,7 @@
 using Phantom.Common.Data.Web.Agent;
 using Phantom.Utils.Events;
 using Phantom.Utils.Logging;
+using Phantom.Web.Services.Authentication;
 
 namespace Phantom.Web.Services.Agents;
 
@@ -18,7 +19,13 @@ public sealed class AgentManager {
 		return agents.Value;
 	}
 	
-	public ImmutableDictionary<Guid, Agent> ToDictionaryByGuid() {
+	public ImmutableDictionary<Guid, Agent> ToDictionaryByGuid(AuthenticatedUser? authenticatedUser) {
-		return agents.Value.ToImmutableDictionary(static agent => agent.AgentGuid);
+		if (authenticatedUser == null) {
+			return ImmutableDictionary<Guid, Agent>.Empty;
+		}
+		
+		return agents.Value
+		             .Where(agent => authenticatedUser.Info.HasAccessToAgent(agent.AgentGuid))
+		             .ToImmutableDictionary(static agent => agent.AgentGuid);
 	}
 }

Web/Phantom.Web.Services/Authentication/AuthenticatedUser.cs

@@ -0,0 +1,6 @@
+using System.Collections.Immutable;
+using Phantom.Common.Data.Web.Users;
+
+namespace Phantom.Web.Services.Authentication;
+
+public sealed record AuthenticatedUser(AuthenticatedUserInfo Info, ImmutableArray<byte> Token);

Web/Phantom.Web.Services/Authentication/AuthenticationStateExtensions.cs

@@ -0,0 +1,31 @@
+using System.Security.Claims;
+using Microsoft.AspNetCore.Components.Authorization;
+using Phantom.Common.Data.Web.Users;
+
+namespace Phantom.Web.Services.Authentication;
+
+public static class AuthenticationStateExtensions {
+	public static AuthenticatedUser? GetAuthenticatedUser(this AuthenticationState authenticationState) {
+		return authenticationState.User.GetAuthenticatedUser();
+	}
+	
+	public static AuthenticatedUser? GetAuthenticatedUser(this ClaimsPrincipal claimsPrincipal) {
+		return claimsPrincipal is CustomClaimsPrincipal principal ? principal.User : null;
+	}
+	
+	public static PermissionSet GetPermissions(this AuthenticationState authenticationState) {
+		return authenticationState.User.GetPermissions();
+	}
+	
+	public static PermissionSet GetPermissions(this ClaimsPrincipal claimsPrincipal) {
+		return claimsPrincipal.GetAuthenticatedUser() is {} user ? user.Info.Permissions : PermissionSet.None;
+	}
+	
+	public static bool CheckPermission(this AuthenticationState authenticationState, Permission permission) {
+		return authenticationState.User.CheckPermission(permission);
+	}
+	
+	public static bool CheckPermission(this ClaimsPrincipal claimsPrincipal, Permission permission) {
+		return claimsPrincipal.GetPermissions().Check(permission);
+	}
+}

Web/Phantom.Web.Services/Authentication/CustomAuthenticationStateProvider.cs

@@ -1,40 +1,121 @@
 using System.Security.Claims;
 using Microsoft.AspNetCore.Components.Authorization;
 using Microsoft.AspNetCore.Components.Server;
+using Phantom.Common.Data;
+using Phantom.Common.Data.Web.Users;
+using Phantom.Common.Messages.Web.ToController;
+using Phantom.Utils.Logging;
+using Phantom.Web.Services.Rpc;
+using ILogger = Serilog.ILogger;
 
 namespace Phantom.Web.Services.Authentication;
 
-public sealed class CustomAuthenticationStateProvider : ServerAuthenticationStateProvider {
+public sealed class CustomAuthenticationStateProvider : ServerAuthenticationStateProvider, IAsyncDisposable {
-	private readonly UserSessionManager sessionManager;
+	private static readonly ILogger Logger = PhantomLogger.Create<CustomAuthenticationStateProvider>();
-	private readonly UserSessionBrowserStorage sessionBrowserStorage;
-	private bool isLoaded;
 	
-	public CustomAuthenticationStateProvider(UserSessionManager sessionManager, UserSessionBrowserStorage sessionBrowserStorage) {
+	private readonly UserSessionRefreshManager sessionRefreshManager;
-		this.sessionManager = sessionManager;
+	private readonly UserSessionBrowserStorage sessionBrowserStorage;
+	private readonly ControllerConnection controllerConnection;
+	
+	private readonly SemaphoreSlim loadSemaphore = new (1);
+	private bool isLoaded = false;
+	private CancellationTokenSource? loadCancellationTokenSource;
+	private UserSessionRefreshManager.EventHolder? userRefreshEventHolder;
+	
+	public CustomAuthenticationStateProvider(UserSessionRefreshManager sessionRefreshManager, UserSessionBrowserStorage sessionBrowserStorage, ControllerConnection controllerConnection) {
+		this.sessionRefreshManager = sessionRefreshManager;
 		this.sessionBrowserStorage = sessionBrowserStorage;
+		this.controllerConnection = controllerConnection;
 	}
 	
 	public override async Task<AuthenticationState> GetAuthenticationStateAsync() {
 		if (!isLoaded) {
-			var stored = await sessionBrowserStorage.Get();
+			await LoadSession();
-			if (stored != null) {
-				var session = sessionManager.FindWithToken(stored.UserGuid, stored.Token);
-				if (session != null) {
-					SetLoadedSession(session);
-				}
-			}
 		}
 		
 		return await base.GetAuthenticationStateAsync();
 	}
 	
-	internal void SetLoadedSession(UserInfo user) {
+	private async Task LoadSession() {
+		await CancelCurrentLoad();
+		await loadSemaphore.WaitAsync(CancellationToken.None);
+		
+		loadCancellationTokenSource = new CancellationTokenSource();
+		CancellationToken cancellationToken = loadCancellationTokenSource.Token;
+		
+		try {
+			var authenticatedUser = await TryGetSession(cancellationToken);
+			if (authenticatedUser != null) {
+				SetLoadedSession(authenticatedUser);
+			}
+			else {
+				SetUnloadedSession();
+			}
+		} catch (OperationCanceledException) {
+			SetUnloadedSession();
+		} catch (Exception e) {
+			SetUnloadedSession();
+			Logger.Error(e, "Could not load user session.");
+		} finally {
+			loadCancellationTokenSource.Dispose();
+			loadCancellationTokenSource = null;
+			loadSemaphore.Release();
+		}
+	}
+	
+	private async Task CancelCurrentLoad() {
+		var cancellationTokenSource = loadCancellationTokenSource;
+		if (cancellationTokenSource != null) {
+			await cancellationTokenSource.CancelAsync();
+		}
+	}
+	
+	private async Task<AuthenticatedUser?> TryGetSession(CancellationToken cancellationToken) {
+		var stored = await sessionBrowserStorage.Get();
+		if (stored == null) {
+			return null;
+		}
+		
+		cancellationToken.ThrowIfCancellationRequested();
+		
+		var userGuid = stored.UserGuid;
+		var authToken = stored.Token;
+		
+		if (userRefreshEventHolder == null) {
+			userRefreshEventHolder = sessionRefreshManager.GetEventHolder(userGuid);
+			userRefreshEventHolder.UserNeedsRefresh += OnUserNeedsRefresh;
+		}
+		
+		var session = await controllerConnection.Send<GetAuthenticatedUser, Optional<AuthenticatedUserInfo>>(new GetAuthenticatedUser(userGuid, authToken), TimeSpan.FromSeconds(30), cancellationToken);
+		if (session.Value is {} userInfo) {
+			return new AuthenticatedUser(userInfo, authToken);
+		}
+		else {
+			return null;
+		}
+	}
+	
+	private void SetLoadedSession(AuthenticatedUser authenticatedUser) {
+		SetAuthenticationState(Task.FromResult(new AuthenticationState(new CustomClaimsPrincipal(authenticatedUser))));
 		isLoaded = true;
-		SetAuthenticationState(Task.FromResult(new AuthenticationState(user.AsClaimsPrincipal)));
 	}
 	
 	internal void SetUnloadedSession() {
-		isLoaded = false;
 		SetAuthenticationState(Task.FromResult(new AuthenticationState(new ClaimsPrincipal())));
+		isLoaded = false;
+	}
+	
+	private void OnUserNeedsRefresh(object? sender, EventArgs args) {
+		_ = LoadSession();
+	}
+	
+	public async ValueTask DisposeAsync() {
+		if (userRefreshEventHolder != null) {
+			userRefreshEventHolder.UserNeedsRefresh -= OnUserNeedsRefresh;
+			userRefreshEventHolder = null;
+		}
+		
+		await CancelCurrentLoad();
+		loadSemaphore.Dispose();
 	}
 }

Web/Phantom.Web.Services/Authentication/CustomClaimsPrincipal.cs

@@ -0,0 +1,18 @@
+using System.Security.Claims;
+using Phantom.Common.Data.Web.Users;
+
+namespace Phantom.Web.Services.Authentication;
+
+sealed class CustomClaimsPrincipal : ClaimsPrincipal {
+	internal AuthenticatedUser User { get; }
+	
+	internal CustomClaimsPrincipal(AuthenticatedUser user) : base(GetIdentity(user.Info)) {
+		User = user;
+	}
+	
+	private static ClaimsIdentity GetIdentity(AuthenticatedUserInfo userInfo) {
+		var identity = new ClaimsIdentity("Phantom");
+		identity.AddClaim(new Claim(ClaimTypes.Name, userInfo.Name));
+		return identity;
+	}
+}

Web/Phantom.Web.Services/Authentication/UserInfo.cs

@@ -1,23 +0,0 @@
-using System.Security.Claims;
-using Phantom.Common.Data.Web.Users;
-
-namespace Phantom.Web.Services.Authentication;
-
-public sealed record UserInfo(Guid UserGuid, string Username, PermissionSet Permissions) {
-	private const string AuthenticationType = "Phantom";
-
-	internal ClaimsPrincipal AsClaimsPrincipal {
-		get {
-			var identity = new ClaimsIdentity(AuthenticationType);
-
-			identity.AddClaim(new Claim(ClaimTypes.Name, Username));
-			identity.AddClaim(new Claim(ClaimTypes.NameIdentifier, UserGuid.ToString()));
-
-			return new ClaimsPrincipal(identity);
-		}
-	}
-
-	public static Guid? TryGetGuid(ClaimsPrincipal principal) {
-		return principal.Identity is { IsAuthenticated: true, AuthenticationType: AuthenticationType } && principal.FindFirstValue(ClaimTypes.NameIdentifier) is {} guidStr && Guid.TryParse(guidStr, out var guid) ? guid : null;
-	}
-}

Web/Phantom.Web.Services/Authentication/UserLoginManager.cs

@@ -1,4 +1,5 @@
-using Phantom.Common.Data.Web.Users;
+using Phantom.Common.Data;
+using Phantom.Common.Data.Web.Users;
 using Phantom.Common.Messages.Web.ToController;
 using Phantom.Utils.Logging;
 using Phantom.Web.Services.Rpc;
@@ -10,42 +11,35 @@ public sealed class UserLoginManager {
 	private static readonly ILogger Logger = PhantomLogger.Create<UserLoginManager>();
 	
 	private readonly Navigation navigation;
-	private readonly UserSessionManager sessionManager;
 	private readonly UserSessionBrowserStorage sessionBrowserStorage;
 	private readonly CustomAuthenticationStateProvider authenticationStateProvider;
 	private readonly ControllerConnection controllerConnection;
 	
-	public UserLoginManager(Navigation navigation, UserSessionManager sessionManager, UserSessionBrowserStorage sessionBrowserStorage, CustomAuthenticationStateProvider authenticationStateProvider, ControllerConnection controllerConnection) {
+	public UserLoginManager(Navigation navigation, UserSessionBrowserStorage sessionBrowserStorage, CustomAuthenticationStateProvider authenticationStateProvider, ControllerConnection controllerConnection) {
 		this.navigation = navigation;
-		this.sessionManager = sessionManager;
 		this.sessionBrowserStorage = sessionBrowserStorage;
 		this.authenticationStateProvider = authenticationStateProvider;
 		this.controllerConnection = controllerConnection;
 	}
 	
 	public async Task<bool> LogIn(string username, string password, string? returnUrl = null) {
-		LogInSuccess? success;
+		Optional<LogInSuccess> result;
 		try {
-			success = await controllerConnection.Send<LogInMessage, LogInSuccess?>(new LogInMessage(username, password), TimeSpan.FromSeconds(30));
+			result = await controllerConnection.Send<LogInMessage, Optional<LogInSuccess>>(new LogInMessage(username, password), TimeSpan.FromSeconds(30));
 		} catch (Exception e) {
 			Logger.Error(e, "Could not log in {Username}.", username);
 			return false;
 		}
 		
-		if (success == null) {
+		if (result.Value is not var (userInfo, authToken)) {
 			return false;
 		}
 		
 		Logger.Information("Successfully logged in {Username}.", username);
 		
-		var userGuid = success.UserGuid;
+		authenticationStateProvider.SetUnloadedSession();
-		var userInfo = new UserInfo(userGuid, username, success.Permissions);
+		await sessionBrowserStorage.Store(userInfo.Guid, authToken);
-		var token = success.Token;
+		await authenticationStateProvider.GetAuthenticationStateAsync();
-
-		await sessionBrowserStorage.Store(userGuid, token);
-		sessionManager.Add(userInfo, token);
-		
-		authenticationStateProvider.SetLoadedSession(userInfo);
 		await navigation.NavigateTo(returnUrl ?? string.Empty);
 		
 		return true;
@@ -53,7 +47,7 @@ public sealed class UserLoginManager {
 	
 	public async Task LogOut() {
 		var stored = await sessionBrowserStorage.Delete();
-		if (stored != null && sessionManager.Remove(stored.UserGuid, stored.Token)) {
+		if (stored != null) {
 			await controllerConnection.Send(new LogOutMessage(stored.UserGuid, stored.Token));
 		}
 		

Web/Phantom.Web.Services/Authentication/UserSessionManager.cs

@@ -1,35 +0,0 @@
-using System.Collections.Concurrent;
-using System.Collections.Immutable;
-
-namespace Phantom.Web.Services.Authentication;
-
-public sealed class UserSessionManager {
-	private readonly ConcurrentDictionary<Guid, UserSessions> userSessions = new ();
-
-	internal void Add(UserInfo user, ImmutableArray<byte> token) {
-		userSessions.AddOrUpdate(
-			user.UserGuid,
-			static (_, u) => new UserSessions(u),
-			static (_, sessions, u) => sessions.WithUserInfo(u),
-			user
-		).AddToken(token);
-	}
-
-	internal UserInfo? Find(Guid userGuid) {
-		return userSessions.TryGetValue(userGuid, out var sessions) ? sessions.UserInfo : null;
-	}
-	
-	internal UserInfo? FindWithToken(Guid userGuid, ImmutableArray<byte> token) {
-		return userSessions.TryGetValue(userGuid, out var sessions) && sessions.HasToken(token) ? sessions.UserInfo : null;
-	}
-
-	internal bool Remove(Guid userGuid, ImmutableArray<byte> token) {
-		if (userSessions.TryGetValue(userGuid, out var sessions)) {
-			sessions.RemoveToken(token);
-			return true;
-		}
-		else {
-			return false;
-		}
-	}
-}

Web/Phantom.Web.Services/Authentication/UserSessionRefreshManager.cs

@@ -0,0 +1,25 @@
+using System.Collections.Concurrent;
+
+namespace Phantom.Web.Services.Authentication;
+
+public sealed class UserSessionRefreshManager {
+	private readonly ConcurrentDictionary<Guid, EventHolder> userUpdateEventHoldersByUserGuid = new ();
+	
+	internal EventHolder GetEventHolder(Guid userGuid) {
+		return userUpdateEventHoldersByUserGuid.GetOrAdd(userGuid, static _ => new EventHolder());
+	}
+	
+	internal void RefreshUser(Guid userGuid) {
+		if (userUpdateEventHoldersByUserGuid.TryGetValue(userGuid, out var eventHolder)) {
+			eventHolder.Notify();
+		}
+	}
+	
+	internal sealed class EventHolder {
+		public event EventHandler? UserNeedsRefresh;
+		
+		internal void Notify() {
+			UserNeedsRefresh?.Invoke(null, EventArgs.Empty);
+		}
+	}
+}

Web/Phantom.Web.Services/Authentication/UserSessions.cs

@@ -1,54 +0,0 @@
-using System.Collections.Immutable;
-using System.Security.Cryptography;
-
-namespace Phantom.Web.Services.Authentication; 
-
-sealed class UserSessions {
-	public UserInfo UserInfo { get; }
-	
-	private readonly List<ImmutableArray<byte>> tokens = new ();
-	
-	public UserSessions(UserInfo userInfo) {
-		UserInfo = userInfo;
-	}
-
-	private UserSessions(UserInfo userInfo, List<ImmutableArray<byte>> tokens) : this(userInfo) {
-		this.tokens.AddRange(tokens);
-	}
-
-	public UserSessions WithUserInfo(UserInfo user) {
-		List<ImmutableArray<byte>> tokensCopy;
-		lock (tokens) {
-			tokensCopy = new List<ImmutableArray<byte>>(tokens);
-		}
-		
-		return new UserSessions(user, tokensCopy);
-	}
-
-	public void AddToken(ImmutableArray<byte> token) {
-		lock (tokens) {
-			if (!HasToken(token)) {
-				tokens.Add(token);
-			}
-		}
-	}
-
-	public bool HasToken(ImmutableArray<byte> token) {
-		return FindTokenIndex(token) != -1;
-	}
-
-	private int FindTokenIndex(ImmutableArray<byte> token) {
-		lock (tokens) {
-			return tokens.FindIndex(t => CryptographicOperations.FixedTimeEquals(t.AsSpan(), token.AsSpan()));
-		}
-	}
-
-	public void RemoveToken(ImmutableArray<byte> token) {
-		lock (tokens) {
-			int index = FindTokenIndex(token);
-			if (index != -1) {
-				tokens.RemoveAt(index);
-			}
-		}
-	}
-}