refactor(runtime): publish canonical entity object deltas

Issue stable Runtime identities at canonical registration, publish entity and inventory commits through one generation-stamped synchronous stream, and make graphical adapters borrow the same direct views and events as a no-window host. Preserve exact projection teardown and retail mutation order while removing App-side event reconstruction.

Make the hard-recenter ordering fixture independent of the production two-millisecond frame budget so its injected-failure gate is deterministic.

Co-authored-by: Codex <codex@openai.com>

src/AcDream.App/Composition/SessionPlayerComposition.cs

@@ -891,7 +891,7 @@ internal sealed class SessionPlayerCompositionPhase
             liveSessionCommands,
             d.PlayerIdentity,
             live.LiveEntities,
-            d.EntityObjects.Objects,
+            d.EntityObjects,
             d.Chat,
             d.PlayerController,
             worldReveal,

src/AcDream.App/Rendering/GameWindow.cs

@@ -1590,6 +1590,7 @@ public sealed class GameWindow :
             _streamer,
             _equippedChildRenderer,
             _liveEntities,
+            _runtimeEntityObjects,
             _renderSceneShadow,
             _livePresentationBindings,
             _entityEffectAdvance,

src/AcDream.App/Rendering/GameWindowLifetime.cs

@@ -16,6 +16,7 @@ using AcDream.App.World;
 using AcDream.Content;
 using AcDream.Core.Audio;
 using AcDream.Core.Physics;
+using AcDream.Runtime.Entities;
 using AcDream.Runtime.Session;
 using AcDream.UI.Abstractions.Input;
 using DatReaderWriter;
@@ -81,6 +82,7 @@ internal sealed record LiveShutdownRoots(
     LandblockStreamer? Streamer,
     EquippedChildRenderController? EquippedChildren,
     LiveEntityRuntime? LiveEntities,
+    RuntimeEntityObjectLifetime EntityObjects,
     RenderSceneShadowRuntime? RenderSceneShadow,
     LivePresentationRuntimeBindings? PresentationBindings,
     DeferredEntityEffectAdvanceSource EffectAdvance,
@@ -384,6 +386,12 @@ internal static class GameWindowShutdownManifest
                     "shadow render scene",
                     () => live.RenderSceneShadow?.Dispose()),
             ]),
+            new ResourceShutdownStage("runtime entity/object stream",
+            [
+                Hard(
+                    "runtime entity/object lifetime",
+                    live.EntityObjects.Dispose),
+            ]),
             new ResourceShutdownStage("effect dispatch edges",
             [
                 Hard("live-presentation bindings", () => live.PresentationBindings?.Dispose()),

src/AcDream.App/Runtime/CurrentGameRuntimeAdapter.cs

@@ -5,9 +5,9 @@ using AcDream.App.Net;
 using AcDream.App.Streaming;
 using AcDream.App.World;
 using AcDream.Core.Chat;
-using AcDream.Core.Items;
 using AcDream.Core.Selection;
 using AcDream.Runtime;
+using AcDream.Runtime.Entities;
 using AcDream.Runtime.Session;
 using AcDream.UI.Abstractions;
 
@@ -35,7 +35,7 @@ internal sealed class CurrentGameRuntimeAdapter
         ICommandBus commands,
         LocalPlayerIdentityState playerIdentity,
         LiveEntityRuntime entities,
-        ClientObjectTable objects,
+        RuntimeEntityObjectLifetime entityObjects,
         ChatLog chat,
         ILocalPlayerControllerSource playerController,
         WorldRevealCoordinator worldReveal,
@@ -49,17 +49,18 @@ internal sealed class CurrentGameRuntimeAdapter
             session,
             playerIdentity,
             entities,
-            objects,
+            entityObjects,
             chat,
             playerController,
             worldReveal,
             clock);
+        entityObjects.BindEventContext(
+            () => _view.Generation,
+            () => clock.FrameNumber);
         _events = new CurrentGameRuntimeEventAdapter(
             _view,
-            entities,
+            entityObjects,
-            objects,
+            chat);
-            chat,
-            clock);
         _commands = new CurrentGameRuntimeCommandAdapter(
             session,
             sessionHost,

src/AcDream.App/Runtime/CurrentGameRuntimeEventAdapter.cs

@@ -1,8 +1,6 @@
-using AcDream.App.World;
 using AcDream.Core.Chat;
-using AcDream.Core.Items;
-using AcDream.Core.Physics;
 using AcDream.Runtime;
+using AcDream.Runtime.Entities;
 
 namespace AcDream.App.Runtime;
 
@@ -26,31 +24,30 @@ internal interface ICurrentGameRuntimeEventSink
 internal sealed class CurrentGameRuntimeEventAdapter
     : IRuntimeEventSource,
       ICurrentGameRuntimeEventSink,
+      IRuntimeEntityObjectObserver,
       IDisposable
 {
     private readonly CurrentGameRuntimeViewAdapter _view;
-    private readonly LiveEntityRuntime _entities;
+    private readonly RuntimeEntityObjectLifetime _entityObjects;
-    private readonly ClientObjectTable _objects;
     private readonly ChatLog _chat;
-    private readonly IGameRuntimeClock _clock;
-    private readonly RuntimeEventSequencer _events = new();
     private readonly object _observerGate = new();
     private IRuntimeEventObserver[] _observers = [];
+    private IDisposable? _entityObjectSubscription;
     private bool _ownerEventsAttached;
     private bool _disposed;
 
+    internal long DispatchFailureCount { get; private set; }
+    internal Exception? LastDispatchFailure { get; private set; }
+
     public CurrentGameRuntimeEventAdapter(
         CurrentGameRuntimeViewAdapter view,
-        LiveEntityRuntime entities,
+        RuntimeEntityObjectLifetime entityObjects,
-        ClientObjectTable objects,
+        ChatLog chat)
-        ChatLog chat,
-        IGameRuntimeClock clock)
     {
         _view = view ?? throw new ArgumentNullException(nameof(view));
-        _entities = entities ?? throw new ArgumentNullException(nameof(entities));
+        _entityObjects = entityObjects
-        _objects = objects ?? throw new ArgumentNullException(nameof(objects));
+            ?? throw new ArgumentNullException(nameof(entityObjects));
         _chat = chat ?? throw new ArgumentNullException(nameof(chat));
-        _clock = clock ?? throw new ArgumentNullException(nameof(clock));
     }
 
     public IDisposable Subscribe(IRuntimeEventObserver observer)
@@ -106,8 +103,17 @@ internal sealed class CurrentGameRuntimeEventAdapter
             primaryObjectId,
             text);
         foreach (IRuntimeEventObserver observer in observers)
+        {
+            try
+            {
                 observer.OnCommand(in delta);
             }
+            catch (Exception error)
+            {
+                RecordDispatchFailure(error);
+            }
+        }
+    }
 
     public void EmitLifecycle(RuntimeLifecycleState previous)
     {
@@ -123,8 +129,17 @@ internal sealed class CurrentGameRuntimeEventAdapter
             previous,
             current);
         foreach (IRuntimeEventObserver observer in observers)
+        {
+            try
+            {
                 observer.OnLifecycle(in delta);
             }
+            catch (Exception error)
+            {
+                RecordDispatchFailure(error);
+            }
+        }
+    }
 
     private void Unsubscribe(IRuntimeEventObserver observer)
     {
@@ -159,12 +174,7 @@ internal sealed class CurrentGameRuntimeEventAdapter
 
     private void AttachOwnerEvents()
     {
-        _entities.ProjectionVisibilityChanged += OnEntityVisibilityChanged;
+        _entityObjectSubscription = _entityObjects.Events.Subscribe(this);
-        _objects.ObjectAdded += OnObjectAdded;
-        _objects.ObjectUpdated += OnObjectUpdated;
-        _objects.ObjectMoved += OnObjectMoved;
-        _objects.ObjectRemovalClassified += OnObjectRemoved;
-        _objects.Cleared += OnObjectsCleared;
         _chat.EntryAppended += OnChatEntry;
         _ownerEventsAttached = true;
     }
@@ -174,79 +184,43 @@ internal sealed class CurrentGameRuntimeEventAdapter
         if (!_ownerEventsAttached)
             return;
         _chat.EntryAppended -= OnChatEntry;
-        _objects.Cleared -= OnObjectsCleared;
+        _entityObjectSubscription?.Dispose();
-        _objects.ObjectRemovalClassified -= OnObjectRemoved;
+        _entityObjectSubscription = null;
-        _objects.ObjectMoved -= OnObjectMoved;
-        _objects.ObjectUpdated -= OnObjectUpdated;
-        _objects.ObjectAdded -= OnObjectAdded;
-        _entities.ProjectionVisibilityChanged -= OnEntityVisibilityChanged;
         _ownerEventsAttached = false;
     }
 
-    private void OnEntityVisibilityChanged(LiveEntityRecord record, bool visible)
+    public void OnEntity(in RuntimeEntityDelta delta)
     {
         if (!TryObservers(out IRuntimeEventObserver[] observers))
             return;
-        RuntimeEntityChange change = visible
-            ? RuntimeEntityChange.Updated
-            : (record.FinalPhysicsState & PhysicsStateFlags.Hidden) != 0
-                ? RuntimeEntityChange.Hidden
-                : RuntimeEntityChange.Withdrawn;
-        var delta = new RuntimeEntityDelta(
-            NextStamp(),
-            change,
-            CurrentGameRuntimeViewAdapter.Snapshot(record));
         foreach (IRuntimeEventObserver observer in observers)
+        {
+            try
+            {
                 observer.OnEntity(in delta);
             }
-
+            catch (Exception error)
-    private void OnObjectAdded(ClientObject item) =>
-        EmitInventory(RuntimeInventoryChange.Added, item);
-
-    private void OnObjectUpdated(ClientObject item) =>
-        EmitInventory(RuntimeInventoryChange.Updated, item);
-
-    private void OnObjectMoved(ClientObjectMove move)
             {
-        ClientObject? item = move.Item ?? _objects.Get(move.ItemId);
+                RecordDispatchFailure(error);
-        if (item is not null)
+            }
-            EmitInventory(RuntimeInventoryChange.Moved, item);
+        }
     }
 
-    private void OnObjectRemoved(ClientObjectRemoval removal) =>
+    public void OnInventory(in RuntimeInventoryDelta delta)
-        EmitInventory(
-            RuntimeInventoryChange.Removed,
-            removal.Object,
-            removal.Generation);
-
-    private void OnObjectsCleared()
     {
         if (!TryObservers(out IRuntimeEventObserver[] observers))
             return;
-        var delta = new RuntimeInventoryDelta(
-            NextStamp(),
-            RuntimeInventoryChange.Cleared,
-            default);
         foreach (IRuntimeEventObserver observer in observers)
+        {
+            try
+            {
                 observer.OnInventory(in delta);
             }
-
+            catch (Exception error)
-    private void EmitInventory(
-        RuntimeInventoryChange change,
-        ClientObject item,
-        ushort? exactGeneration = null)
             {
-        if (!TryObservers(out IRuntimeEventObserver[] observers))
+                RecordDispatchFailure(error);
-            return;
+            }
-        var delta = new RuntimeInventoryDelta(
+        }
-            NextStamp(),
-            change,
-            CurrentGameRuntimeViewAdapter.Snapshot(
-                item,
-                _entities,
-                exactGeneration));
-        foreach (IRuntimeEventObserver observer in observers)
-            observer.OnInventory(in delta);
     }
 
     private void OnChatEntry(ChatEntry entry)
@@ -263,11 +237,20 @@ internal sealed class CurrentGameRuntimeEventAdapter
                 entry.Text,
                 entry.ChannelName));
         foreach (IRuntimeEventObserver observer in observers)
+        {
+            try
+            {
                 observer.OnChat(in delta);
             }
+            catch (Exception error)
+            {
+                RecordDispatchFailure(error);
+            }
+        }
+    }
 
     private RuntimeEventStamp NextStamp() =>
-        _events.Next(_view.Generation, _clock.FrameNumber);
+        _entityObjects.Events.NextStamp();
 
     private bool TryObservers(out IRuntimeEventObserver[] observers)
     {
@@ -275,6 +258,12 @@ internal sealed class CurrentGameRuntimeEventAdapter
         return observers.Length != 0;
     }
 
+    private void RecordDispatchFailure(Exception error)
+    {
+        DispatchFailureCount++;
+        LastDispatchFailure = error;
+    }
+
     private sealed class ObserverSubscription(
         CurrentGameRuntimeEventAdapter owner,
         IRuntimeEventObserver observer)

src/AcDream.App/Runtime/CurrentGameRuntimeViewAdapter.cs

@@ -5,6 +5,7 @@ using AcDream.App.World;
 using AcDream.Core.Chat;
 using AcDream.Core.Items;
 using AcDream.Runtime;
+using AcDream.Runtime.Entities;
 using AcDream.Runtime.Session;
 
 namespace AcDream.App.Runtime;
@@ -21,8 +22,8 @@ internal sealed class CurrentGameRuntimeViewAdapter : IGameRuntimeView
     private readonly ClientObjectTable _objects;
     private readonly ChatLog _chat;
     private readonly IGameRuntimeClock _clock;
-    private readonly EntityView _entityView;
+    private readonly IRuntimeEntityView _entityView;
-    private readonly InventoryView _inventoryView;
+    private readonly IRuntimeInventoryView _inventoryView;
     private readonly ChatView _chatView;
     private readonly MovementView _movementView;
     private readonly PortalView _portalView;
@@ -32,7 +33,7 @@ internal sealed class CurrentGameRuntimeViewAdapter : IGameRuntimeView
         LiveSessionController session,
         LocalPlayerIdentityState playerIdentity,
         LiveEntityRuntime entities,
-        ClientObjectTable objects,
+        RuntimeEntityObjectLifetime entityObjects,
         ChatLog chat,
         ILocalPlayerControllerSource playerController,
         WorldRevealCoordinator worldReveal,
@@ -42,12 +43,13 @@ internal sealed class CurrentGameRuntimeViewAdapter : IGameRuntimeView
         _playerIdentity = playerIdentity
             ?? throw new ArgumentNullException(nameof(playerIdentity));
         _entities = entities ?? throw new ArgumentNullException(nameof(entities));
-        _objects = objects ?? throw new ArgumentNullException(nameof(objects));
+        ArgumentNullException.ThrowIfNull(entityObjects);
+        _objects = entityObjects.Objects;
         _chat = chat ?? throw new ArgumentNullException(nameof(chat));
         _clock = clock ?? throw new ArgumentNullException(nameof(clock));
 
-        _entityView = new EntityView(_entities);
+        _entityView = entityObjects.EntityView;
-        _inventoryView = new InventoryView(_objects, _entities);
+        _inventoryView = entityObjects.InventoryView;
         _chatView = new ChatView(_chat);
         _movementView = new MovementView(
             playerController
@@ -108,103 +110,6 @@ internal sealed class CurrentGameRuntimeViewAdapter : IGameRuntimeView
 
     internal void Deactivate() => _active = false;
 
-    internal static RuntimeEntitySnapshot Snapshot(LiveEntityRecord record) =>
-        new(
-            new RuntimeEntityIdentity(
-                record.ServerGuid,
-                record.LocalEntityId ?? 0u,
-                record.Generation),
-            record.FullCellId,
-            (uint)record.FinalPhysicsState,
-            record.PhysicsBody?.CellPosition,
-            record.LocalEntityId.HasValue,
-            record.IsSpatiallyVisible,
-            record.InitialHydrationCompleted);
-
-    internal static RuntimeInventoryItemSnapshot Snapshot(
-        ClientObject item,
-        LiveEntityRuntime entities,
-        ushort? exactGeneration = null)
-    {
-        ushort generation = exactGeneration
-            ?? (entities.TryGetRecord(item.ObjectId, out LiveEntityRecord record)
-                ? record.Generation
-                : (ushort)0);
-        return new RuntimeInventoryItemSnapshot(
-            item.ObjectId,
-            generation,
-            item.Name,
-            item.ContainerId,
-            item.ContainerSlot,
-            item.WielderId,
-            (uint)item.CurrentlyEquippedLocation,
-            item.StackSize,
-            item.Value);
-    }
-
-    private sealed class EntityView(LiveEntityRuntime owner)
-        : IRuntimeEntityView
-    {
-        public int Count => owner.Count;
-        public int MaterializedCount => owner.MaterializedCount;
-
-        public bool TryGet(uint serverGuid, out RuntimeEntitySnapshot entity)
-        {
-            if (owner.TryGetRecord(serverGuid, out LiveEntityRecord record))
-            {
-                entity = Snapshot(record);
-                return true;
-            }
-
-            entity = default;
-            return false;
-        }
-
-        public void Visit(IRuntimeEntityVisitor visitor)
-        {
-            ArgumentNullException.ThrowIfNull(visitor);
-            foreach (LiveEntityRecord record in owner.Records)
-            {
-                RuntimeEntitySnapshot entity = Snapshot(record);
-                visitor.Visit(in entity);
-            }
-        }
-    }
-
-    private sealed class InventoryView(
-        ClientObjectTable owner,
-        LiveEntityRuntime entities)
-        : IRuntimeInventoryView
-    {
-        public int ObjectCount => owner.ObjectCount;
-        public int ContainerCount => owner.ContainerCount;
-
-        public bool TryGet(
-            uint objectId,
-            out RuntimeInventoryItemSnapshot item)
-        {
-            ClientObject? found = owner.Get(objectId);
-            if (found is not null)
-            {
-                item = Snapshot(found, entities);
-                return true;
-            }
-
-            item = default;
-            return false;
-        }
-
-        public void Visit(IRuntimeInventoryVisitor visitor)
-        {
-            ArgumentNullException.ThrowIfNull(visitor);
-            foreach (ClientObject item in owner.Objects)
-            {
-                RuntimeInventoryItemSnapshot snapshot = Snapshot(item, entities);
-                visitor.Visit(in snapshot);
-            }
-        }
-    }
-
     private sealed class ChatView(ChatLog owner) : IRuntimeChatView
     {
         public long Revision => owner.Revision;

src/AcDream.App/World/LiveEntityRuntime.cs

@@ -3,6 +3,7 @@ using AcDream.Core.Net;
 using AcDream.Core.Net.Messages;
 using AcDream.Core.Physics;
 using AcDream.Core.World;
+using AcDream.Runtime;
 using AcDream.Runtime.Entities;
 using System.Numerics;
 using System.Runtime.ExceptionServices;
@@ -377,29 +378,13 @@ public sealed class LiveEntityRecord
     internal RetailPhysicsStateTransition ApplyRawPhysicsState(uint rawState) =>
         _directory.ApplyRawPhysicsState(Canonical, rawState);
 
-    internal void AdvancePositionAuthority() =>
+    internal void NoteObjDescProjectionSynchronization()
-        _directory.AdvancePositionAuthority(Canonical);
-
-    internal void AdvanceVectorAuthority() =>
-        _directory.AdvanceVectorAuthority(Canonical);
-
-    internal void AdvanceMovementAuthority() =>
-        _directory.AdvanceMovementAuthority(Canonical);
-
-    internal void AdvanceObjDescAuthority()
     {
-        _directory.AdvanceObjDescAuthority(Canonical);
         AppearanceProjectionSynchronizationPending = true;
         if (AppearanceHydrationInProgress)
             AppearanceHydrationRetryRequested = true;
     }
 
-    internal void AdvanceCreateAuthority() =>
-        _directory.AdvanceCreateAuthority(Canonical);
-
-    internal void SetChildNoDraw(bool noDraw) =>
-        _directory.SetChildNoDraw(Canonical, noDraw);
-
     /// <summary>
     /// Cell used when a streamed landblock asks live objects to restore their
     /// spatial projection. Once materialized, the canonical runtime cell wins;
@@ -582,150 +567,26 @@ public sealed class LiveEntityRuntime : ILiveEntityRadarSource
                     : "A live entity cannot register from inside atomic resource registration.");
         }
 
-        InboundCreateResult result = _directory.AcceptCreate(incoming);
+        RuntimeEntityRegistrationResult registration =
-        if (result.Disposition is CreateObjectTimestampDisposition.StaleGeneration)
+            _entityObjects.RegisterEntity(
+                incoming,
+                RetirePriorProjection);
+        RuntimeEntityRecord? canonical = registration.Canonical;
+        LiveEntityRecord? projection = canonical is null
+            ? null
+            : _projections.GetCurrentOrDefault(canonical.ServerGuid);
+        if (projection is not null
+            && ReferenceEquals(projection.Canonical, canonical))
+        {
+            RefreshSpatialRuntimeIndexes(projection);
+        }
         return new LiveEntityRegistrationResult(
-                result,
+            registration.Inbound,
-                Canonical: null,
-                Projection: null,
-                LogicalRegistrationCreated: false,
-                ReplacedExistingGeneration: false);
-        ulong sessionVersion = _directory.SessionLifetimeVersion;
-        ulong operationVersion = AdvanceLifetimeMutation(incoming.Guid);
-
-        if (result.Disposition is CreateObjectTimestampDisposition.ExistingGeneration)
-        {
-            if (_directory.TryGetActive(
-                    incoming.Guid,
-                    out RuntimeEntityRecord retainedCanonical))
-            {
-                _directory.RefreshSnapshot(
-                    retainedCanonical,
-                    result.Snapshot,
-                    refreshPosition: true);
-                _directory.AdvanceCreateAuthority(retainedCanonical);
-                _projections.TryGet(
-                    retainedCanonical,
-                    out LiveEntityRecord? retainedProjection);
-                if (retainedProjection is not null)
-                    RefreshSpatialRuntimeIndexes(retainedProjection);
-                return new LiveEntityRegistrationResult(
-                    result,
-                    retainedCanonical,
-                    retainedProjection,
-                    LogicalRegistrationCreated: false,
-                    ReplacedExistingGeneration: false);
-            }
-
-            // A failed materialization rollback retains this exact incarnation
-            // as a teardown tombstone. Do not create a second active record
-            // with the same (GUID, INSTANCE_TS) while its partial resources are
-            // still converging; a later retransmit can recover after teardown.
-            if (_directory.TryGetTeardown(
-                    incoming.Guid,
-                    result.Snapshot.InstanceSequence,
-                    out _))
-            {
-                return new LiveEntityRegistrationResult(
-                    result,
-                    Canonical: null,
-                    Projection: null,
-                    false,
-                    false);
-            }
-
-            // Defensive repair for a caller that cleared only the logical map.
-            // Normal session teardown clears both owners together.
-            RuntimeEntityRecord recoveredCanonical =
-                _directory.AddActive(result.Snapshot);
-            return new LiveEntityRegistrationResult(
-                result,
-                recoveredCanonical,
-                Projection: null,
-                LogicalRegistrationCreated: true,
-                ReplacedExistingGeneration: false);
-        }
-
-        bool replaced = _directory.RemoveActive(
-            incoming.Guid,
-            out RuntimeEntityRecord? oldCanonical);
-        LiveEntityRecord? old = null;
-        if (oldCanonical is not null
-            && _projections.TryGet(oldCanonical, out LiveEntityRecord? projected))
-        {
-            old = projected;
-            if (!_projections.RemoveActive(old))
-            {
-                throw new InvalidOperationException(
-                    $"Exact App projection for 0x{incoming.Guid:X8}/{old.Generation} could not be retired.");
-            }
-        }
-        if (result.Disposition is CreateObjectTimestampDisposition.NewGeneration)
-            ParentAttachments.EndGeneration(incoming.Guid, result.Snapshot.InstanceSequence);
-
-        Exception? tearDownFailure = null;
-        if (old is not null)
-        {
-            RetainTeardownRecord(old);
-            _logicalTeardownDepth++;
-            try
-            {
-                try
-                {
-                    TearDownRecord(old);
-                    ReleaseTeardownRecord(old);
-                }
-                catch (Exception error)
-                {
-                    tearDownFailure = error;
-                }
-            }
-            finally
-            {
-                _logicalTeardownDepth--;
-            }
-        }
-        else if (oldCanonical is not null)
-        {
-            TearDownCanonicalOnly(oldCanonical);
-        }
-
-        // Resource callbacks are arbitrary App integration code. Any nested
-        // create, accepted delete, or session reset advances this epoch. The
-        // outer packet is then superseded even when the nested action left no
-        // record/snapshot (delete/reset); reinstalling it would resurrect an
-        // incarnation after an accepted terminal event.
-        if (_directory.SessionLifetimeVersion != sessionVersion
-            || CurrentLifetimeMutation(incoming.Guid) != operationVersion)
-        {
-            if (tearDownFailure is not null)
-            {
-                throw new AggregateException(
-                    $"Prior incarnation of live entity 0x{incoming.Guid:X8} failed teardown while its incoming replacement was superseded.",
-                    tearDownFailure);
-            }
-
-            return new LiveEntityRegistrationResult(
-                SupersededCreateResult(),
-                _directory.TryGetActive(
-                    incoming.Guid,
-                    out RuntimeEntityRecord currentCanonical)
-                        ? currentCanonical
-                        : null,
-                _projections.GetCurrentOrDefault(incoming.Guid),
-                false,
-                replaced,
-                tearDownFailure);
-        }
-
-        RuntimeEntityRecord canonical = _directory.AddActive(result.Snapshot);
-        return new LiveEntityRegistrationResult(
-            result,
             canonical,
-            Projection: null,
+            projection,
-            true,
+            registration.LogicalRegistrationCreated,
-            replaced,
+            registration.ReplacedExistingGeneration,
-            tearDownFailure);
+            registration.PriorGenerationCleanupFailure);
     }
 
     /// <summary>
@@ -785,7 +646,9 @@ public sealed class LiveEntityRuntime : ILiveEntityRadarSource
         bool createdSidecar = false;
         if (!_projections.TryGet(expectedCanonical, out record))
         {
-            uint localId = _directory.ClaimLocalId(expectedCanonical);
+            _ = expectedCanonical.LocalEntityId
+                ?? throw new InvalidOperationException(
+                    "Runtime must issue entity identity before App projection.");
             try
             {
                 record = _projections.AddMaterializing(expectedCanonical);
@@ -800,7 +663,6 @@ public sealed class LiveEntityRuntime : ILiveEntityRadarSource
                     record.ProjectionKey = null;
                     record = null;
                 }
-                _directory.ReleaseLocalId(expectedCanonical);
                 throw;
             }
         }
@@ -833,7 +695,6 @@ public sealed class LiveEntityRuntime : ILiveEntityRadarSource
                 {
                     _projections.RemoveActive(record);
                     record.ProjectionKey = null;
-                    _directory.ReleaseLocalId(expectedCanonical);
                     record = null;
                 }
                 throw;
@@ -870,14 +731,13 @@ public sealed class LiveEntityRuntime : ILiveEntityRadarSource
                     {
                         _projections.RemoveActive(record);
                         record.ProjectionKey = null;
-                        _directory.ReleaseLocalId(expectedCanonical);
                         record.WorldEntity = null;
                         record = null;
                         throw;
                     }
 
-                    if (_directory.IsCurrent(expectedCanonical))
+                    _entityObjects.RetireAfterProjectionAcquisitionFailure(
-                        _directory.RemoveActive(expectedCanonical);
+                        expectedCanonical);
                     if (_projections.RemoveActive(record))
                     {
                         RetainTeardownRecord(record);
@@ -983,11 +843,24 @@ public sealed class LiveEntityRuntime : ILiveEntityRadarSource
         bool visible = _spatial.IsLiveEntityProjectionResident(key);
         record.IsSpatiallyVisible = visible;
         RefreshPresentation(record);
-        if ((spatialCellOrLandblockId & 0xFFFFu) != 0xFFFFu)
+        uint committedFullCell =
-            record.FullCellId = spatialCellOrLandblockId;
+            (spatialCellOrLandblockId & 0xFFFFu) != 0xFFFFu
-        record.CanonicalLandblockId = spatialCellOrLandblockId == 0
+                ? spatialCellOrLandblockId
+                : record.FullCellId;
+        uint committedLandblock = spatialCellOrLandblockId == 0
             ? 0u
             : (spatialCellOrLandblockId & 0xFFFF0000u) | 0xFFFFu;
+        if (!_entityObjects.CommitRebucket(
+                record.Canonical,
+                committedFullCell,
+                committedLandblock))
+        {
+            ThrowAfterCommittedProjectionChange(
+                serverGuid,
+                spatialNotificationFailure,
+                runtimeNotificationFailure: null);
+            return false;
+        }
         bool isOrdinaryRoot = record.ProjectionKind is LiveEntityProjectionKind.World
             && record.IsSpatiallyProjected
             && record.IsSpatiallyVisible
@@ -1182,7 +1055,12 @@ public sealed class LiveEntityRuntime : ILiveEntityRadarSource
             return false;
         }
 
-        ClearWorldCell(serverGuid);
+        if (!_entityObjects.CommitWithdrawal(
+                record.Canonical,
+                AcknowledgeCelllessCanonicalCommit))
+        {
+            return false;
+        }
         record.WorldEntity.ParentCellId = 0u;
         return WithdrawLiveEntityProjection(serverGuid);
     }
@@ -1218,10 +1096,9 @@ public sealed class LiveEntityRuntime : ILiveEntityRadarSource
             if (!_entityObjects.TryAcceptDelete(
                     delete,
                     isLocalPlayer,
+                    removeRetainedObject,
                     out acceptedDelete))
                 return false;
-            AdvanceLifetimeMutation(delete.Guid);
-            ParentAttachments.DeleteGeneration(delete.Guid, delete.InstanceSequence);
 
             // End active gameplay identity before arbitrary callbacks so a
             // newer generation can be accepted re-entrantly, but retain the
@@ -1229,11 +1106,7 @@ public sealed class LiveEntityRuntime : ILiveEntityRadarSource
             // succeeded. A throwing resource callback can then be retried by
             // the same accepted Delete instead of orphaning its owner.
             LiveEntityRecord? retainedRegistrationFailure = record;
-            if (_directory.TryGetActive(
+            if (acceptedDelete.RetiredCanonical is { } activeCanonical)
-                    delete.Guid,
-                    out RuntimeEntityRecord activeCanonical)
-                && activeCanonical.Incarnation == delete.InstanceSequence
-                && _directory.RemoveActive(activeCanonical))
             {
                 if (_projections.TryGet(
                         activeCanonical,
@@ -1265,8 +1138,6 @@ public sealed class LiveEntityRuntime : ILiveEntityRadarSource
         try
         {
             if (!retryingAcceptedDelete)
-            {
-                if (removeRetainedObject)
             {
                 try
                 {
@@ -1276,7 +1147,6 @@ public sealed class LiveEntityRuntime : ILiveEntityRadarSource
                 {
                     (failures ??= new List<Exception>()).Add(error);
                 }
-                }
 
                 try
                 {
@@ -1872,95 +1742,44 @@ public sealed class LiveEntityRuntime : ILiveEntityRadarSource
         _directory.TryGetSnapshot(guid, out spawn);
 
     public bool TryApplyObjDesc(ObjDescEvent.Parsed update, out WorldSession.EntitySpawn accepted)
+        => _entityObjects.TryApplyObjDesc(
+            update,
+            canonical =>
             {
-        bool applied = _directory.TryApplyObjDesc(update, out accepted);
+                if (_projections.TryGet(
-        if (applied
+                        canonical,
-            && _directory.TryGetActive(
+                        out LiveEntityRecord? record))
-                update.Guid,
-                out RuntimeEntityRecord canonical))
                 {
-            _directory.RefreshSnapshot(canonical, accepted);
+                    record.NoteObjDescProjectionSynchronization();
-            if (_projections.TryGet(canonical, out LiveEntityRecord? record))
-                record.AdvanceObjDescAuthority();
-            else
-                _directory.AdvanceObjDescAuthority(canonical);
-        }
-        return applied;
                 }
+            },
+            out accepted);
 
     public bool TryApplyPickup(PickupEvent.Parsed update, out WorldSession.EntitySpawn accepted)
-    {
+        => _entityObjects.TryApplyPickup(
-        bool applied = _directory.TryApplyPickup(update, out accepted);
+            update,
-        if (applied
+            AcknowledgeCelllessCanonicalCommit,
-            && _directory.TryGetActive(
+            out accepted);
-                update.Guid,
-                out RuntimeEntityRecord canonical))
-        {
-            _directory.RefreshSnapshot(canonical, accepted);
-            if (_projections.TryGet(canonical, out LiveEntityRecord? record))
-                record.AdvancePositionAuthority();
-            else
-                _directory.AdvancePositionAuthority(canonical);
-            ClearWorldCell(canonical);
-            ParentAttachments.EndChildProjection(update.Guid);
-        }
-        return applied;
-    }
 
     public bool TryApplyCreateParent(CreateParentUpdate update, out WorldSession.EntitySpawn accepted)
-    {
+        => _entityObjects.TryApplyCreateParent(
-        bool applied = _directory.TryApplyCreateParent(update, out accepted);
+            update,
-        if (applied
+            acknowledgeProjection: null,
-            && _directory.TryGetActive(
+            out accepted);
-                update.ChildGuid,
-                out RuntimeEntityRecord canonical))
-        {
-            _directory.RefreshSnapshot(canonical, accepted);
-            if (_projections.TryGet(canonical, out LiveEntityRecord? record))
-                record.AdvancePositionAuthority();
-            else
-                _directory.AdvancePositionAuthority(canonical);
-        }
-        return applied;
-    }
 
     public bool TryApplyParent(ParentEvent.Parsed update, out WorldSession.EntitySpawn accepted)
-    {
+        => _entityObjects.TryApplyParent(
-        bool applied = _directory.TryApplyParent(update, out accepted);
+            update,
-        if (applied
+            acknowledgeProjection: null,
-            && _directory.TryGetActive(
+            out accepted);
-                update.ChildGuid,
-                out RuntimeEntityRecord canonical))
-        {
-            _directory.RefreshSnapshot(canonical, accepted);
-            if (_projections.TryGet(canonical, out LiveEntityRecord? record))
-                record.AdvancePositionAuthority();
-            else
-                _directory.AdvancePositionAuthority(canonical);
-        }
-        return applied;
-    }
 
     internal bool CommitStagedParent(
         ParentAttachmentRelation relation,
         out WorldSession.EntitySpawn accepted)
-    {
+        => _entityObjects.TryCommitParent(
-        bool committed = _directory.TryCommitParent(
+            relation,
-            relation.ChildGuid,
+            acknowledgeProjection: null,
-            relation.ParentGuid,
-            relation.ParentLocation,
-            relation.PlacementId,
-            relation.ChildPositionSequence,
             out accepted);
-        if (committed
-            && _directory.TryGetActive(
-                relation.ChildGuid,
-                out RuntimeEntityRecord canonical))
-        {
-            _directory.RefreshSnapshot(canonical, accepted);
-        }
-        return committed;
-    }
 
     /// <summary>
     /// Commits retail <c>CPhysicsObj::set_parent</c>'s cell-less edge only
@@ -1973,25 +1792,20 @@ public sealed class LiveEntityRuntime : ILiveEntityRadarSource
         ulong positionAuthorityVersion)
     {
         ArgumentNullException.ThrowIfNull(record);
-        if (!IsCurrentPositionAuthority(record, positionAuthorityVersion))
+        return _entityObjects.CommitAcceptedParentCellless(
-            return false;
+            record.Canonical,
-        ClearWorldCell(record.ServerGuid);
+            positionAuthorityVersion,
-        return IsCurrentPositionAuthority(record, positionAuthorityVersion);
+            AcknowledgeCelllessCanonicalCommit);
     }
 
     internal bool CommitAcceptedParentCellless(
         RuntimeEntityRecord canonical,
         ulong positionAuthorityVersion)
     {
-        ArgumentNullException.ThrowIfNull(canonical);
+        return _entityObjects.CommitAcceptedParentCellless(
-        if (!_directory.IsCurrent(canonical)
+            canonical,
-            || canonical.PositionAuthorityVersion != positionAuthorityVersion)
+            positionAuthorityVersion,
-        {
+            AcknowledgeCelllessCanonicalCommit);
-            return false;
-        }
-        ClearWorldCell(canonical);
-        return _directory.IsCurrent(canonical)
-            && canonical.PositionAuthorityVersion == positionAuthorityVersion;
     }
 
     public bool TryApplyMotion(
@@ -1999,43 +1813,18 @@ public sealed class LiveEntityRuntime : ILiveEntityRadarSource
         bool retainPayload,
         out WorldSession.EntitySpawn accepted,
         out AcceptedPhysicsTimestamps timestamps)
-    {
+        => _entityObjects.TryApplyMotion(
-        bool applied = _directory.TryApplyMotion(update, retainPayload, out accepted, out timestamps);
+            update,
-        if (_directory.TryGetSnapshot(update.Guid, out WorldSession.EntitySpawn snapshot)
+            retainPayload,
-            && _directory.TryGetActive(
+            acknowledgeProjection: null,
-                update.Guid,
+            out accepted,
-                out RuntimeEntityRecord canonical))
+            out timestamps);
-        {
-            _directory.RefreshSnapshot(canonical, snapshot);
-        }
-        if (applied
-            && retainPayload
-            && _directory.TryGetActive(update.Guid, out canonical))
-        {
-            if (_projections.TryGet(canonical, out LiveEntityRecord? record))
-                record.AdvanceMovementAuthority();
-            else
-                _directory.AdvanceMovementAuthority(canonical);
-        }
-        return applied;
-    }
 
     public bool TryApplyVector(VectorUpdate.Parsed update, out WorldSession.EntitySpawn accepted)
-    {
+        => _entityObjects.TryApplyVector(
-        bool applied = _directory.TryApplyVector(update, out accepted);
+            update,
-        if (applied
+            acknowledgeProjection: null,
-            && _directory.TryGetActive(
+            out accepted);
-                update.Guid,
-                out RuntimeEntityRecord canonical))
-        {
-            _directory.RefreshSnapshot(canonical, accepted);
-            if (_projections.TryGet(canonical, out LiveEntityRecord? record))
-                record.AdvanceVectorAuthority();
-            else
-                _directory.AdvanceVectorAuthority(canonical);
-        }
-        return applied;
-    }
 
     public bool TryApplyState(SetState.Parsed update, out WorldSession.EntitySpawn accepted)
         => TryApplyState(update, out accepted, out _);
@@ -2044,23 +1833,19 @@ public sealed class LiveEntityRuntime : ILiveEntityRadarSource
         SetState.Parsed update,
         out WorldSession.EntitySpawn accepted,
         out RetailPhysicsStateTransition transition)
+        => _entityObjects.TryApplyState(
+            update,
+            (canonical, _) =>
             {
-        bool applied = _directory.TryApplyState(update, out accepted);
+                if (_projections.TryGet(
-        transition = default;
-        if (applied
-            && _directory.TryGetActive(
-                update.Guid,
-                out RuntimeEntityRecord canonical))
-        {
-            _directory.RefreshSnapshot(canonical, accepted);
-            transition = _directory.ApplyRawPhysicsState(
                         canonical,
-                update.PhysicsState);
+                        out LiveEntityRecord? record))
-            if (_projections.TryGet(canonical, out LiveEntityRecord? record))
+                {
                     RefreshPresentation(record);
                 }
-        return applied;
+            },
-    }
+            out accepted,
+            out transition);
 
     /// <summary>
     /// Retail parent Hidden directly toggles each attached child's NoDraw bit
@@ -2070,9 +1855,10 @@ public sealed class LiveEntityRuntime : ILiveEntityRadarSource
     {
         if (!_projections.TryGetCurrent(childServerGuid, out LiveEntityRecord? record))
             return false;
-        record.SetChildNoDraw(noDraw);
+        return _entityObjects.CommitChildNoDraw(
-        RefreshPresentation(record);
+            record.Canonical,
-        return true;
+            noDraw,
+            _ => RefreshPresentation(record));
     }
 
     public bool TryApplyPosition(
@@ -2084,62 +1870,26 @@ public sealed class LiveEntityRuntime : ILiveEntityRadarSource
         out WorldSession.EntitySpawn accepted,
         out AcceptedPhysicsTimestamps timestamps)
     {
-        bool hadCanonical = _directory.TryGetActive(
+        bool projectionRequiresTeleportHook =
+            _directory.TryGetActive(
                 update.Guid,
-            out RuntimeEntityRecord? beforeCanonical);
+                out RuntimeEntityRecord canonical)
-        LiveEntityRecord? beforePosition = null;
+            && (canonical.FullCellId == 0u
-        if (hadCanonical)
+                || !_projections.TryGet(
-            _projections.TryGet(beforeCanonical!, out beforePosition);
+                    canonical,
-        bool wasCellLess = hadCanonical
+                    out LiveEntityRecord? projection)
-            && (beforeCanonical!.FullCellId == 0
+                || !projection.IsSpatiallyProjected
-                || beforePosition is null
+                || !projection.IsSpatiallyVisible);
-                || !beforePosition.IsSpatiallyProjected
+        return _entityObjects.TryApplyPosition(
-                || !beforePosition.IsSpatiallyVisible);
-        bool known = _directory.TryApplyPosition(
             update,
             isLocalPlayer,
             forcePositionRotation,
             currentLocalVelocity,
+            projectionRequiresTeleportHook,
+            acknowledgeProjection: null,
             out disposition,
             out accepted,
             out timestamps);
-        if (known && _directory.TryGetSnapshot(update.Guid, out WorldSession.EntitySpawn snapshot))
-        {
-            bool acceptedPosition = disposition is not PositionTimestampDisposition.Rejected;
-            if (disposition is PositionTimestampDisposition.Apply)
-            {
-                timestamps = timestamps with
-                {
-                    TeleportHookRequired = timestamps.TeleportAdvanced || wasCellLess,
-                };
-            }
-            if (_directory.TryGetActive(
-                    update.Guid,
-                    out RuntimeEntityRecord acceptedCanonical))
-            {
-                _directory.RefreshSnapshot(
-                    acceptedCanonical,
-                    snapshot,
-                    refreshPosition: acceptedPosition);
-                if (acceptedPosition
-                    && ReferenceEquals(acceptedCanonical, beforeCanonical))
-                {
-                    if (_projections.TryGet(
-                            acceptedCanonical,
-                            out LiveEntityRecord? acceptedRecord)
-                        && ReferenceEquals(acceptedRecord, beforePosition))
-                    {
-                        acceptedRecord.AdvancePositionAuthority();
-                    }
-                    else
-                    {
-                        _directory.AdvancePositionAuthority(acceptedCanonical);
-                    }
-                    ParentAttachments.EndChildProjection(update.Guid);
-                }
-            }
-        }
-        return known;
     }
 
     public bool IsFreshTeleportStart(uint localPlayerGuid, ushort teleportSequence) =>
@@ -2669,15 +2419,13 @@ public sealed class LiveEntityRuntime : ILiveEntityRadarSource
 
         _isClearing = true;
         _sessionClearPendingFinalization = true;
-        _directory.BeginSessionClear();
+        IReadOnlyList<RuntimeEntityRecord> retiredCanonicals =
+            _entityObjects.BeginSessionClear();
         List<Exception>? failures = null;
         try
         {
-            foreach (RuntimeEntityRecord canonical in
+            foreach (RuntimeEntityRecord canonical in retiredCanonicals)
-                     _directory.ActiveRecords.ToArray())
             {
-                if (!_directory.RemoveActive(canonical))
-                    continue;
                 if (_projections.TryGet(
                         canonical,
                         out LiveEntityRecord? record))
@@ -2796,12 +2544,6 @@ public sealed class LiveEntityRuntime : ILiveEntityRadarSource
         _directory.RefreshSnapshot(canonical, accepted, refreshPosition);
     }
 
-    private static InboundCreateResult SupersededCreateResult() => new(
-        CreateObjectTimestampDisposition.StaleGeneration,
-        default,
-        null,
-        default);
-
     private ulong AdvanceLifetimeMutation(uint serverGuid)
         => _directory.AdvanceLifetimeMutation(serverGuid);
 
@@ -2841,37 +2583,18 @@ public sealed class LiveEntityRuntime : ILiveEntityRadarSource
             ExceptionDispatchInfo.Capture(failure).Throw();
     }
 
-    private void ClearWorldCell(uint guid)
+    private void AcknowledgeCelllessCanonicalCommit(
+        RuntimeEntityRecord canonical)
+    {
+        if (!_directory.IsCurrent(canonical)
+            || !_projections.TryGet(
+                canonical,
+                out LiveEntityRecord? record))
         {
-        if (!_directory.TryGetActive(guid, out RuntimeEntityRecord canonical))
             return;
-        ClearWorldCell(canonical);
         }
 
-    private void ClearWorldCell(RuntimeEntityRecord canonical)
-    {
-        if (!_directory.IsCurrent(canonical))
-            return;
-        if (!_projections.TryGet(canonical, out LiveEntityRecord? record))
-        {
-            _directory.SetFullCell(canonical, 0, 0);
-            return;
-        }
-        bool wasOrdinaryRoot = record.ProjectionKey is { } key
-            && _spatialRootObjects.TryGetValue(
-                key,
-                out LiveEntityRecord? indexedRoot)
-            && ReferenceEquals(indexedRoot, record);
-        // Pickup/Parent is retail's leave-world edge. Suspend the canonical
-        // object clock while the record is still indexed as a root; clearing
-        // FullCellId first removes that evidence and makes the later projection
-        // withdrawal look like a duplicate non-root edge.
-        if (wasOrdinaryRoot)
-        {
-            record.SuspendObjectClock();
         SynchronizePhysicsBodyActiveState(record);
-        }
-        _directory.SetFullCell(canonical, 0, 0);
         RefreshSpatialRuntimeIndexes(record);
     }
 
@@ -3091,27 +2814,50 @@ public sealed class LiveEntityRuntime : ILiveEntityRadarSource
         _projections.RetainTeardown(record);
     }
 
-    private void TearDownCanonicalOnly(RuntimeEntityRecord canonical)
+    private Exception? RetirePriorProjection(
+        RuntimeEntityRecord canonical)
     {
-        // A canonical-only incarnation has never crossed the App projection
+        if (!_projections.TryGet(
-        // acquisition edge, so it owns no renderer/effect/animation suffix.
+                canonical,
-        // Retain it briefly only so Runtime's validated mutators can converge
+                out LiveEntityRecord? projection))
-        // any presentation-free physics state before the tombstone vanishes.
+        {
-        _directory.RetainTeardown(canonical);
+            return _entityObjects.RetireCanonicalOnly(canonical);
+        }
+
+        if (!_projections.RemoveActive(projection))
+        {
+            return new InvalidOperationException(
+                $"Exact App projection for 0x{canonical.ServerGuid:X8}/{canonical.Incarnation} could not be retired.");
+        }
+
+        RetainTeardownRecord(projection);
+        _logicalTeardownDepth++;
         try
         {
-            _directory.SetPhysicsHost(canonical, null);
+            try
-            _directory.SetPhysicsBody(canonical, null);
+            {
-            _directory.SetPhysicsBodyAcquisitionInProgress(canonical, false);
+                TearDownRecord(projection);
-            _directory.SetHasPartArray(canonical, false);
+                ReleaseTeardownRecord(projection);
-            _directory.ReleaseLocalId(canonical);
+                return null;
+            }
+            catch (Exception error)
+            {
+                return error;
+            }
         }
         finally
         {
-            _directory.ReleaseTeardown(canonical);
+            _logicalTeardownDepth--;
         }
     }
 
+    private void TearDownCanonicalOnly(RuntimeEntityRecord canonical)
+    {
+        Exception? failure = _entityObjects.RetireCanonicalOnly(canonical);
+        if (failure is not null)
+            ExceptionDispatchInfo.Capture(failure).Throw();
+    }
+
     private void ReleaseTeardownRecord(LiveEntityRecord record)
     {
         _projections.ReleaseTeardown(record);
@@ -3125,7 +2871,7 @@ public sealed class LiveEntityRuntime : ILiveEntityRadarSource
     private void CompleteSessionClearIfConverged()
     {
         if (!_sessionClearPendingFinalization
-            || !_directory.CompleteSessionClearIfConverged())
+            || !_entityObjects.CompleteSessionClearIfConverged())
         {
             return;
         }

src/AcDream.Runtime/Entities/RuntimeEntityDirectory.cs

@@ -80,8 +80,17 @@ public sealed class RuntimeEntityDirectory
 
         var record = new RuntimeEntityRecord(snapshot);
         _activeByGuid.Add(snapshot.Guid, record);
+        try
+        {
+            ClaimLocalId(record);
             return record;
         }
+        catch
+        {
+            _activeByGuid.Remove(snapshot.Guid);
+            throw;
+        }
+    }
 
     public bool RemoveActive(uint guid, out RuntimeEntityRecord? record) =>
         _activeByGuid.Remove(guid, out record);

src/AcDream.Runtime/Entities/RuntimeEntityObjectEventStream.cs

@@ -0,0 +1,271 @@
+using AcDream.Core.Items;
+
+namespace AcDream.Runtime.Entities;
+
+public interface IRuntimeEntityObjectObserver
+{
+    void OnEntity(in RuntimeEntityDelta delta);
+
+    void OnInventory(in RuntimeInventoryDelta delta);
+}
+
+public interface IRuntimeEntityObjectEventSource
+{
+    IDisposable Subscribe(IRuntimeEntityObjectObserver observer);
+}
+
+/// <summary>
+/// One synchronous, generation-stamped commit stream for the canonical entity
+/// directory and retained object table. It owns no queue and dispatches on the
+/// caller's update/network-drain thread.
+/// </summary>
+public sealed class RuntimeEntityObjectEventStream
+    : IRuntimeEntityObjectEventSource,
+      IDisposable
+{
+    private readonly RuntimeEntityDirectory _entities;
+    private readonly ClientObjectTable _objects;
+    private readonly RuntimeEventSequencer _sequencer = new();
+    private readonly object _observerGate = new();
+    private IRuntimeEntityObjectObserver[] _observers = [];
+    private Func<RuntimeGenerationToken> _generation = static () => default;
+    private Func<ulong> _frameNumber = static () => 0UL;
+    private bool _contextBound;
+    private bool _disposed;
+
+    internal RuntimeEntityObjectEventStream(
+        RuntimeEntityDirectory entities,
+        ClientObjectTable objects)
+    {
+        _entities = entities
+            ?? throw new ArgumentNullException(nameof(entities));
+        _objects = objects ?? throw new ArgumentNullException(nameof(objects));
+        _objects.ObjectAdded += OnObjectAdded;
+        _objects.ObjectUpdated += OnObjectUpdated;
+        _objects.ObjectMoved += OnObjectMoved;
+        _objects.ObjectRemovalClassified += OnObjectRemoved;
+        _objects.Cleared += OnObjectsCleared;
+    }
+
+    public ulong LastSequence => _sequencer.LastSequence;
+    public int SubscriberCount => Volatile.Read(ref _observers).Length;
+    public long DispatchFailureCount { get; private set; }
+    public Exception? LastDispatchFailure { get; private set; }
+
+    /// <summary>
+    /// Binds the session-generation and Runtime-frame sources exactly once.
+    /// Both are queried at commit time so reconnect/reset cannot stamp an event
+    /// with a cached generation.
+    /// </summary>
+    public void BindContext(
+        Func<RuntimeGenerationToken> generation,
+        Func<ulong> frameNumber)
+    {
+        ArgumentNullException.ThrowIfNull(generation);
+        ArgumentNullException.ThrowIfNull(frameNumber);
+        lock (_observerGate)
+        {
+            ObjectDisposedException.ThrowIf(_disposed, this);
+            if (_contextBound)
+            {
+                throw new InvalidOperationException(
+                    "The Runtime entity/object event context is already bound.");
+            }
+
+            _generation = generation;
+            _frameNumber = frameNumber;
+            _contextBound = true;
+        }
+    }
+
+    public IDisposable Subscribe(IRuntimeEntityObjectObserver observer)
+    {
+        ArgumentNullException.ThrowIfNull(observer);
+        lock (_observerGate)
+        {
+            ObjectDisposedException.ThrowIf(_disposed, this);
+            IRuntimeEntityObjectObserver[] current = _observers;
+            if (Array.IndexOf(current, observer) >= 0)
+            {
+                throw new InvalidOperationException(
+                    "The Runtime entity/object observer is already subscribed.");
+            }
+
+            var replacement =
+                new IRuntimeEntityObjectObserver[current.Length + 1];
+            Array.Copy(current, replacement, current.Length);
+            replacement[^1] = observer;
+            Volatile.Write(ref _observers, replacement);
+        }
+
+        return new ObserverSubscription(this, observer);
+    }
+
+    /// <summary>
+    /// Allocates the next stamp for another domain on the same Runtime event
+    /// surface. J4–J6 will move those remaining domain publishers into
+    /// Runtime; until then the App adapter borrows this sequencer.
+    /// </summary>
+    public RuntimeEventStamp NextStamp()
+    {
+        ObjectDisposedException.ThrowIf(
+            Volatile.Read(ref _disposed),
+            this);
+        return _sequencer.Next(_generation(), _frameNumber());
+    }
+
+    internal void PublishEntity(
+        RuntimeEntityChange change,
+        RuntimeEntityRecord record)
+    {
+        ArgumentNullException.ThrowIfNull(record);
+        var delta = new RuntimeEntityDelta(
+            NextStamp(),
+            change,
+            RuntimeEntityObjectViews.Snapshot(record));
+        IRuntimeEntityObjectObserver[] observers =
+            Volatile.Read(ref _observers);
+        foreach (IRuntimeEntityObjectObserver observer in observers)
+        {
+            try
+            {
+                observer.OnEntity(in delta);
+            }
+            catch (Exception error)
+            {
+                RecordDispatchFailure(error);
+            }
+        }
+    }
+
+    public void Dispose()
+    {
+        lock (_observerGate)
+        {
+            if (_disposed)
+                return;
+            _disposed = true;
+            Volatile.Write(ref _observers, []);
+            _objects.Cleared -= OnObjectsCleared;
+            _objects.ObjectRemovalClassified -= OnObjectRemoved;
+            _objects.ObjectMoved -= OnObjectMoved;
+            _objects.ObjectUpdated -= OnObjectUpdated;
+            _objects.ObjectAdded -= OnObjectAdded;
+        }
+    }
+
+    private void OnObjectAdded(ClientObject item) =>
+        PublishInventory(RuntimeInventoryChange.Added, item);
+
+    private void OnObjectUpdated(ClientObject item) =>
+        PublishInventory(RuntimeInventoryChange.Updated, item);
+
+    private void OnObjectMoved(ClientObjectMove move)
+    {
+        ClientObject? item = move.Item ?? _objects.Get(move.ItemId);
+        RuntimeInventoryItemSnapshot snapshot = item is null
+            ? new RuntimeInventoryItemSnapshot(
+                move.ItemId,
+                0,
+                string.Empty,
+                move.Current.ContainerId,
+                move.Current.ContainerSlot,
+                move.Current.WielderId,
+                (uint)move.Current.EquipLocation,
+                0,
+                0)
+            : RuntimeEntityObjectViews.Snapshot(item, _entities);
+        PublishInventory(RuntimeInventoryChange.Moved, snapshot);
+    }
+
+    private void OnObjectRemoved(ClientObjectRemoval removal) =>
+        PublishInventory(
+            RuntimeInventoryChange.Removed,
+            RuntimeEntityObjectViews.Snapshot(
+                removal.Object,
+                _entities,
+                removal.Generation));
+
+    private void OnObjectsCleared() =>
+        PublishInventory(
+            RuntimeInventoryChange.Cleared,
+            default(RuntimeInventoryItemSnapshot));
+
+    private void PublishInventory(
+        RuntimeInventoryChange change,
+        ClientObject item) =>
+        PublishInventory(
+            change,
+            RuntimeEntityObjectViews.Snapshot(item, _entities));
+
+    private void PublishInventory(
+        RuntimeInventoryChange change,
+        RuntimeInventoryItemSnapshot item)
+    {
+        var delta = new RuntimeInventoryDelta(
+            NextStamp(),
+            change,
+            item);
+        IRuntimeEntityObjectObserver[] observers =
+            Volatile.Read(ref _observers);
+        foreach (IRuntimeEntityObjectObserver observer in observers)
+        {
+            try
+            {
+                observer.OnInventory(in delta);
+            }
+            catch (Exception error)
+            {
+                RecordDispatchFailure(error);
+            }
+        }
+    }
+
+    private void RecordDispatchFailure(Exception error)
+    {
+        DispatchFailureCount++;
+        LastDispatchFailure = error;
+    }
+
+    private void Unsubscribe(IRuntimeEntityObjectObserver observer)
+    {
+        lock (_observerGate)
+        {
+            IRuntimeEntityObjectObserver[] current = _observers;
+            int index = Array.IndexOf(current, observer);
+            if (index < 0)
+                return;
+            if (current.Length == 1)
+            {
+                Volatile.Write(ref _observers, []);
+                return;
+            }
+
+            var replacement =
+                new IRuntimeEntityObjectObserver[current.Length - 1];
+            if (index != 0)
+                Array.Copy(current, 0, replacement, 0, index);
+            if (index != current.Length - 1)
+            {
+                Array.Copy(
+                    current,
+                    index + 1,
+                    replacement,
+                    index,
+                    current.Length - index - 1);
+            }
+            Volatile.Write(ref _observers, replacement);
+        }
+    }
+
+    private sealed class ObserverSubscription(
+        RuntimeEntityObjectEventStream owner,
+        IRuntimeEntityObjectObserver observer)
+        : IDisposable
+    {
+        private RuntimeEntityObjectEventStream? _owner = owner;
+
+        public void Dispose() =>
+            Interlocked.Exchange(ref _owner, null)?.Unsubscribe(observer);
+    }
+}

src/AcDream.Runtime/Entities/RuntimeEntityObjectLifetime.cs

@@ -1,9 +1,17 @@
 using AcDream.Core.Items;
 using AcDream.Core.Net;
 using AcDream.Core.Net.Messages;
+using AcDream.Core.Physics;
 
 namespace AcDream.Runtime.Entities;
 
+public readonly record struct RuntimeEntityRegistrationResult(
+    InboundCreateResult Inbound,
+    RuntimeEntityRecord? Canonical,
+    bool LogicalRegistrationCreated,
+    bool ReplacedExistingGeneration,
+    Exception? PriorGenerationCleanupFailure = null);
+
 /// <summary>
 /// One exact DeleteObject acceptance issued by a
 /// <see cref="RuntimeEntityObjectLifetime"/>. The graphical host retires the
@@ -14,15 +22,21 @@ public sealed class RuntimeEntityDeleteAcceptance
 {
     internal RuntimeEntityDeleteAcceptance(
         RuntimeEntityObjectLifetime owner,
-        DeleteObject.Parsed delete)
+        DeleteObject.Parsed delete,
+        RuntimeEntityRecord? retiredCanonical,
+        bool removeRetainedObject)
     {
         Owner = owner;
         Delete = delete;
+        RetiredCanonical = retiredCanonical;
+        RemoveRetainedObject = removeRetainedObject;
     }
 
     internal RuntimeEntityObjectLifetime Owner { get; }
     internal bool Completed { get; set; }
     public DeleteObject.Parsed Delete { get; }
+    public RuntimeEntityRecord? RetiredCanonical { get; }
+    public bool RemoveRetainedObject { get; }
 }
 
 /// <summary>
@@ -30,17 +44,253 @@ public sealed class RuntimeEntityDeleteAcceptance
 /// retained object lifetimes. Graphical and direct hosts borrow these exact
 /// instances; they never allocate a second directory or object table.
 /// </summary>
-public sealed class RuntimeEntityObjectLifetime
+public sealed class RuntimeEntityObjectLifetime : IDisposable
 {
+    private bool _sessionClearInProgress;
+    private bool _disposed;
+
     public RuntimeEntityObjectLifetime(
         uint firstLocalEntityId = RuntimeEntityDirectory.FirstLocalEntityId)
     {
         Entities = new RuntimeEntityDirectory(firstLocalEntityId);
         Objects = new ClientObjectTable();
+        var views = new RuntimeEntityObjectViews(Entities, Objects);
+        EntityView = views.Entities;
+        InventoryView = views.Inventory;
+        Events = new RuntimeEntityObjectEventStream(Entities, Objects);
     }
 
     public RuntimeEntityDirectory Entities { get; }
     public ClientObjectTable Objects { get; }
+    public IRuntimeEntityView EntityView { get; }
+    public IRuntimeInventoryView InventoryView { get; }
+    public RuntimeEntityObjectEventStream Events { get; }
+
+    public void BindEventContext(
+        Func<RuntimeGenerationToken> generation,
+        Func<ulong> frameNumber)
+    {
+        EnsureNotDisposed();
+        Events.BindContext(generation, frameNumber);
+    }
+
+    /// <summary>
+    /// Owns the presentation-free half of retail's CreateObject lifetime
+    /// transaction. An attached graphical host may synchronously retire the
+    /// displaced projection through <paramref name="retirePriorProjection"/>;
+    /// a direct host omits it and Runtime retires canonical-only state.
+    /// </summary>
+    public RuntimeEntityRegistrationResult RegisterEntity(
+        WorldSession.EntitySpawn incoming,
+        Func<RuntimeEntityRecord, Exception?>? retirePriorProjection = null)
+    {
+        EnsureNotDisposed();
+        if (_sessionClearInProgress)
+        {
+            throw new InvalidOperationException(
+                "A Runtime entity cannot register while its session lifetime is clearing.");
+        }
+
+        InboundCreateResult result = Entities.AcceptCreate(incoming);
+        if (result.Disposition
+            is CreateObjectTimestampDisposition.StaleGeneration)
+        {
+            return new RuntimeEntityRegistrationResult(
+                result,
+                Canonical: null,
+                LogicalRegistrationCreated: false,
+                ReplacedExistingGeneration: false);
+        }
+
+        ulong sessionVersion = Entities.SessionLifetimeVersion;
+        ulong operationVersion =
+            Entities.AdvanceLifetimeMutation(incoming.Guid);
+
+        if (result.Disposition
+            is CreateObjectTimestampDisposition.ExistingGeneration)
+        {
+            if (Entities.TryGetActive(
+                    incoming.Guid,
+                    out RuntimeEntityRecord retained))
+            {
+                Entities.RefreshSnapshot(
+                    retained,
+                    result.Snapshot,
+                    refreshPosition: true);
+                Entities.AdvanceCreateAuthority(retained);
+                PublishEntity(RuntimeEntityChange.Updated, retained);
+                if (!IsCurrentOperation(
+                        incoming.Guid,
+                        retained,
+                        sessionVersion,
+                        operationVersion))
+                {
+                    return SupersededRegistration(
+                        incoming.Guid,
+                        replacedExistingGeneration: false);
+                }
+                return new RuntimeEntityRegistrationResult(
+                    result,
+                    retained,
+                    LogicalRegistrationCreated: false,
+                    ReplacedExistingGeneration: false);
+            }
+
+            if (Entities.TryGetTeardown(
+                    incoming.Guid,
+                    result.Snapshot.InstanceSequence,
+                    out _))
+            {
+                return new RuntimeEntityRegistrationResult(
+                    result,
+                    Canonical: null,
+                    LogicalRegistrationCreated: false,
+                    ReplacedExistingGeneration: false);
+            }
+
+            RuntimeEntityRecord recovered = Entities.AddActive(result.Snapshot);
+            PublishEntity(RuntimeEntityChange.Registered, recovered);
+            if (!IsCurrentOperation(
+                    incoming.Guid,
+                    recovered,
+                    sessionVersion,
+                    operationVersion))
+            {
+                return SupersededRegistration(
+                    incoming.Guid,
+                    replacedExistingGeneration: false);
+            }
+            return new RuntimeEntityRegistrationResult(
+                result,
+                recovered,
+                LogicalRegistrationCreated: true,
+                ReplacedExistingGeneration: false);
+        }
+
+        bool replaced = Entities.RemoveActive(
+            incoming.Guid,
+            out RuntimeEntityRecord? prior);
+        if (result.Disposition
+            is CreateObjectTimestampDisposition.NewGeneration)
+        {
+            Entities.ParentAttachments.EndGeneration(
+                incoming.Guid,
+                result.Snapshot.InstanceSequence);
+        }
+
+        Exception? cleanupFailure = null;
+        if (prior is not null)
+        {
+            try
+            {
+                PublishEntity(RuntimeEntityChange.Deleted, prior);
+            }
+            catch (Exception error)
+            {
+                cleanupFailure = error;
+            }
+
+            Exception? projectionFailure = retirePriorProjection is null
+                ? RetireCanonicalOnly(prior)
+                : retirePriorProjection(prior);
+            cleanupFailure = Combine(cleanupFailure, projectionFailure);
+        }
+
+        if (Entities.SessionLifetimeVersion != sessionVersion
+            || Entities.CurrentLifetimeMutation(incoming.Guid)
+                != operationVersion)
+        {
+            if (cleanupFailure is not null)
+            {
+                throw new AggregateException(
+                    $"Prior incarnation of live entity 0x{incoming.Guid:X8} failed teardown while its incoming replacement was superseded.",
+                    cleanupFailure);
+            }
+
+            return new RuntimeEntityRegistrationResult(
+                SupersededCreateResult(),
+                Entities.TryGetActive(
+                    incoming.Guid,
+                    out RuntimeEntityRecord current)
+                        ? current
+                        : null,
+                LogicalRegistrationCreated: false,
+                ReplacedExistingGeneration: replaced);
+        }
+
+        RuntimeEntityRecord canonical = Entities.AddActive(result.Snapshot);
+        try
+        {
+            PublishEntity(RuntimeEntityChange.Registered, canonical);
+        }
+        catch (Exception error)
+        {
+            if (cleanupFailure is not null)
+            {
+                throw new AggregateException(
+                    $"Live entity 0x{incoming.Guid:X8} registered after prior cleanup and commit observers failed.",
+                    cleanupFailure,
+                    error);
+            }
+            throw;
+        }
+
+        if (!IsCurrentOperation(
+                incoming.Guid,
+                canonical,
+                sessionVersion,
+                operationVersion))
+        {
+            if (cleanupFailure is not null)
+            {
+                throw new AggregateException(
+                    $"Prior incarnation of live entity 0x{incoming.Guid:X8} failed teardown while its committed replacement was superseded.",
+                    cleanupFailure);
+            }
+
+            return SupersededRegistration(
+                incoming.Guid,
+                replaced);
+        }
+
+        return new RuntimeEntityRegistrationResult(
+            result,
+            canonical,
+            LogicalRegistrationCreated: true,
+            ReplacedExistingGeneration: replaced,
+            cleanupFailure);
+    }
+
+    /// <summary>
+    /// Completes a displaced incarnation that never crossed the graphical
+    /// projection acquisition edge.
+    /// </summary>
+    public Exception? RetireCanonicalOnly(RuntimeEntityRecord canonical)
+    {
+        EnsureNotDisposed();
+        ArgumentNullException.ThrowIfNull(canonical);
+        try
+        {
+            Entities.RetainTeardown(canonical);
+            try
+            {
+                Entities.SetPhysicsHost(canonical, null);
+                Entities.SetPhysicsBody(canonical, null);
+                Entities.SetPhysicsBodyAcquisitionInProgress(canonical, false);
+                Entities.SetHasPartArray(canonical, false);
+                Entities.ReleaseLocalId(canonical);
+            }
+            finally
+            {
+                Entities.ReleaseTeardown(canonical);
+            }
+            return null;
+        }
+        catch (Exception error)
+        {
+            return error;
+        }
+    }
 
     /// <summary>
     /// Applies the retained-object half of an accepted CreateObject while the
@@ -54,6 +304,7 @@ public sealed class RuntimeEntityObjectLifetime
         WorldSession.EntitySpawn spawn,
         bool replaceGeneration)
     {
+        EnsureNotDisposed();
         ArgumentNullException.ThrowIfNull(canonical);
         if (canonical.ServerGuid != spawn.Guid
             || canonical.Incarnation != spawn.InstanceSequence)
@@ -75,24 +326,423 @@ public sealed class RuntimeEntityObjectLifetime
             && IsCurrent();
     }
 
+    public bool TryApplyObjDesc(
+        ObjDescEvent.Parsed update,
+        Action<RuntimeEntityRecord>? acknowledgeProjection,
+        out WorldSession.EntitySpawn accepted)
+    {
+        EnsureNotDisposed();
+        bool applied = Entities.TryApplyObjDesc(update, out accepted);
+        if (!applied
+            || !Entities.TryGetActive(
+                update.Guid,
+                out RuntimeEntityRecord canonical))
+        {
+            return applied;
+        }
+
+        Entities.RefreshSnapshot(canonical, accepted);
+        Entities.AdvanceObjDescAuthority(canonical);
+        acknowledgeProjection?.Invoke(canonical);
+        if (!Entities.IsCurrent(canonical))
+            return false;
+        PublishEntity(RuntimeEntityChange.Updated, canonical);
+        return Entities.IsCurrent(canonical);
+    }
+
+    public bool TryApplyPickup(
+        PickupEvent.Parsed update,
+        Action<RuntimeEntityRecord>? acknowledgeProjection,
+        out WorldSession.EntitySpawn accepted)
+    {
+        EnsureNotDisposed();
+        bool applied = Entities.TryApplyPickup(update, out accepted);
+        if (!applied
+            || !Entities.TryGetActive(
+                update.Guid,
+                out RuntimeEntityRecord canonical))
+        {
+            return applied;
+        }
+
+        Entities.RefreshSnapshot(canonical, accepted);
+        Entities.AdvancePositionAuthority(canonical);
+        Entities.SuspendObjectClock(canonical);
+        Entities.SetFullCell(canonical, 0u, 0u);
+        Entities.ParentAttachments.EndChildProjection(update.Guid);
+        acknowledgeProjection?.Invoke(canonical);
+        if (!Entities.IsCurrent(canonical))
+            return false;
+        PublishEntity(RuntimeEntityChange.Withdrawn, canonical);
+        return Entities.IsCurrent(canonical);
+    }
+
+    public bool TryApplyCreateParent(
+        CreateParentUpdate update,
+        Action<RuntimeEntityRecord>? acknowledgeProjection,
+        out WorldSession.EntitySpawn accepted)
+    {
+        EnsureNotDisposed();
+        bool applied = Entities.TryApplyCreateParent(update, out accepted);
+        return CommitPositionChannelUpdate(
+            applied,
+            update.ChildGuid,
+            accepted,
+            acknowledgeProjection);
+    }
+
+    public bool TryApplyParent(
+        ParentEvent.Parsed update,
+        Action<RuntimeEntityRecord>? acknowledgeProjection,
+        out WorldSession.EntitySpawn accepted)
+    {
+        EnsureNotDisposed();
+        bool applied = Entities.TryApplyParent(update, out accepted);
+        return CommitPositionChannelUpdate(
+            applied,
+            update.ChildGuid,
+            accepted,
+            acknowledgeProjection);
+    }
+
+    public bool TryCommitParent(
+        ParentAttachmentRelation relation,
+        Action<RuntimeEntityRecord>? acknowledgeProjection,
+        out WorldSession.EntitySpawn accepted)
+    {
+        EnsureNotDisposed();
+        bool committed = Entities.TryCommitParent(
+            relation.ChildGuid,
+            relation.ParentGuid,
+            relation.ParentLocation,
+            relation.PlacementId,
+            relation.ChildPositionSequence,
+            out accepted);
+        if (!committed
+            || !Entities.TryGetActive(
+                relation.ChildGuid,
+                out RuntimeEntityRecord canonical))
+        {
+            return committed;
+        }
+
+        Entities.RefreshSnapshot(canonical, accepted);
+        acknowledgeProjection?.Invoke(canonical);
+        if (!Entities.IsCurrent(canonical))
+            return false;
+        PublishEntity(RuntimeEntityChange.Updated, canonical);
+        return Entities.IsCurrent(canonical);
+    }
+
+    public bool CommitAcceptedParentCellless(
+        RuntimeEntityRecord canonical,
+        ulong positionAuthorityVersion,
+        Action<RuntimeEntityRecord>? acknowledgeProjection)
+    {
+        EnsureNotDisposed();
+        ArgumentNullException.ThrowIfNull(canonical);
+        if (!Entities.IsCurrent(canonical)
+            || canonical.PositionAuthorityVersion != positionAuthorityVersion)
+        {
+            return false;
+        }
+
+        Entities.SuspendObjectClock(canonical);
+        Entities.SetFullCell(canonical, 0u, 0u);
+        acknowledgeProjection?.Invoke(canonical);
+        if (!Entities.IsCurrent(canonical)
+            || canonical.PositionAuthorityVersion != positionAuthorityVersion)
+        {
+            return false;
+        }
+        PublishEntity(RuntimeEntityChange.Withdrawn, canonical);
+        return Entities.IsCurrent(canonical)
+            && canonical.PositionAuthorityVersion == positionAuthorityVersion;
+    }
+
+    public bool TryApplyMotion(
+        WorldSession.EntityMotionUpdate update,
+        bool retainPayload,
+        Action<RuntimeEntityRecord>? acknowledgeProjection,
+        out WorldSession.EntitySpawn accepted,
+        out AcceptedPhysicsTimestamps timestamps)
+    {
+        EnsureNotDisposed();
+        bool applied = Entities.TryApplyMotion(
+            update,
+            retainPayload,
+            out accepted,
+            out timestamps);
+        if (Entities.TryGetSnapshot(
+                update.Guid,
+                out WorldSession.EntitySpawn snapshot)
+            && Entities.TryGetActive(
+                update.Guid,
+                out RuntimeEntityRecord canonical))
+        {
+            Entities.RefreshSnapshot(canonical, snapshot);
+            if (applied && retainPayload)
+                Entities.AdvanceMovementAuthority(canonical);
+            acknowledgeProjection?.Invoke(canonical);
+            if (applied && Entities.IsCurrent(canonical))
+                PublishEntity(RuntimeEntityChange.Updated, canonical);
+            if (applied && !Entities.IsCurrent(canonical))
+                return false;
+        }
+
+        return applied;
+    }
+
+    public bool TryApplyVector(
+        VectorUpdate.Parsed update,
+        Action<RuntimeEntityRecord>? acknowledgeProjection,
+        out WorldSession.EntitySpawn accepted)
+    {
+        EnsureNotDisposed();
+        bool applied = Entities.TryApplyVector(update, out accepted);
+        if (!applied
+            || !Entities.TryGetActive(
+                update.Guid,
+                out RuntimeEntityRecord canonical))
+        {
+            return applied;
+        }
+
+        Entities.RefreshSnapshot(canonical, accepted);
+        Entities.AdvanceVectorAuthority(canonical);
+        acknowledgeProjection?.Invoke(canonical);
+        if (!Entities.IsCurrent(canonical))
+            return false;
+        PublishEntity(RuntimeEntityChange.Updated, canonical);
+        return Entities.IsCurrent(canonical);
+    }
+
+    public bool TryApplyState(
+        SetState.Parsed update,
+        Action<RuntimeEntityRecord, RetailPhysicsStateTransition>?
+            acknowledgeProjection,
+        out WorldSession.EntitySpawn accepted,
+        out RetailPhysicsStateTransition transition)
+    {
+        EnsureNotDisposed();
+        bool applied = Entities.TryApplyState(update, out accepted);
+        transition = default;
+        if (!applied
+            || !Entities.TryGetActive(
+                update.Guid,
+                out RuntimeEntityRecord canonical))
+        {
+            return applied;
+        }
+
+        Entities.RefreshSnapshot(canonical, accepted);
+        transition = Entities.ApplyRawPhysicsState(
+            canonical,
+            update.PhysicsState);
+        acknowledgeProjection?.Invoke(canonical, transition);
+        if (!Entities.IsCurrent(canonical))
+            return false;
+        PublishEntity(
+            transition.HiddenTransition
+                is RetailHiddenTransition.BecameHidden
+                    ? RuntimeEntityChange.Hidden
+                    : RuntimeEntityChange.Updated,
+            canonical);
+        return Entities.IsCurrent(canonical);
+    }
+
+    public bool TryApplyPosition(
+        WorldSession.EntityPositionUpdate update,
+        bool isLocalPlayer,
+        System.Numerics.Quaternion? forcePositionRotation,
+        System.Numerics.Vector3? currentLocalVelocity,
+        bool projectionRequiresTeleportHook,
+        Action<RuntimeEntityRecord>? acknowledgeProjection,
+        out PositionTimestampDisposition disposition,
+        out WorldSession.EntitySpawn accepted,
+        out AcceptedPhysicsTimestamps timestamps)
+    {
+        EnsureNotDisposed();
+        bool hadCanonical = Entities.TryGetActive(
+            update.Guid,
+            out RuntimeEntityRecord beforeCanonical);
+        uint beforeCell = beforeCanonical?.FullCellId ?? 0u;
+        bool wasCellless = hadCanonical && beforeCell == 0u;
+        bool known = Entities.TryApplyPosition(
+            update,
+            isLocalPlayer,
+            forcePositionRotation,
+            currentLocalVelocity,
+            out disposition,
+            out accepted,
+            out timestamps);
+        if (!known
+            || !Entities.TryGetSnapshot(
+                update.Guid,
+                out WorldSession.EntitySpawn snapshot)
+            || !Entities.TryGetActive(
+                update.Guid,
+                out RuntimeEntityRecord canonical))
+        {
+            return known;
+        }
+
+        bool acceptedPosition =
+            disposition is not PositionTimestampDisposition.Rejected;
+        if (disposition is PositionTimestampDisposition.Apply)
+        {
+            timestamps = timestamps with
+            {
+                TeleportHookRequired =
+                    timestamps.TeleportAdvanced
+                    || wasCellless
+                    || projectionRequiresTeleportHook,
+            };
+        }
+
+        Entities.RefreshSnapshot(
+            canonical,
+            snapshot,
+            refreshPosition: acceptedPosition);
+        if (acceptedPosition
+            && ReferenceEquals(canonical, beforeCanonical))
+        {
+            Entities.AdvancePositionAuthority(canonical);
+            Entities.ParentAttachments.EndChildProjection(update.Guid);
+        }
+
+        acknowledgeProjection?.Invoke(canonical);
+        if (!Entities.IsCurrent(canonical))
+            return false;
+        if (acceptedPosition)
+        {
+            PublishEntity(
+                beforeCell != canonical.FullCellId
+                    ? RuntimeEntityChange.Rebucketed
+                    : RuntimeEntityChange.Updated,
+                canonical);
+        }
+        return Entities.IsCurrent(canonical);
+    }
+
+    public bool CommitRebucket(
+        RuntimeEntityRecord canonical,
+        uint fullCellId,
+        uint canonicalLandblockId,
+        Action<RuntimeEntityRecord>? acknowledgeProjection = null)
+    {
+        EnsureNotDisposed();
+        ArgumentNullException.ThrowIfNull(canonical);
+        if (!Entities.IsCurrent(canonical))
+            return false;
+
+        uint previous = canonical.FullCellId;
+        Entities.SetFullCell(
+            canonical,
+            fullCellId,
+            canonicalLandblockId);
+        acknowledgeProjection?.Invoke(canonical);
+        if (!Entities.IsCurrent(canonical))
+            return false;
+        if (previous != fullCellId)
+            PublishEntity(RuntimeEntityChange.Rebucketed, canonical);
+        return Entities.IsCurrent(canonical);
+    }
+
+    public bool CommitWithdrawal(
+        RuntimeEntityRecord canonical,
+        Action<RuntimeEntityRecord>? acknowledgeProjection = null)
+    {
+        EnsureNotDisposed();
+        ArgumentNullException.ThrowIfNull(canonical);
+        if (!Entities.IsCurrent(canonical))
+            return false;
+
+        Entities.SuspendObjectClock(canonical);
+        Entities.SetFullCell(canonical, 0u, 0u);
+        acknowledgeProjection?.Invoke(canonical);
+        if (!Entities.IsCurrent(canonical))
+            return false;
+        PublishEntity(RuntimeEntityChange.Withdrawn, canonical);
+        return Entities.IsCurrent(canonical);
+    }
+
+    public bool CommitChildNoDraw(
+        RuntimeEntityRecord canonical,
+        bool noDraw,
+        Action<RuntimeEntityRecord>? acknowledgeProjection = null)
+    {
+        EnsureNotDisposed();
+        ArgumentNullException.ThrowIfNull(canonical);
+        if (!Entities.IsCurrent(canonical))
+            return false;
+
+        Entities.SetChildNoDraw(canonical, noDraw);
+        acknowledgeProjection?.Invoke(canonical);
+        if (!Entities.IsCurrent(canonical))
+            return false;
+        PublishEntity(RuntimeEntityChange.Updated, canonical);
+        return Entities.IsCurrent(canonical);
+    }
+
+    public bool RetireAfterProjectionAcquisitionFailure(
+        RuntimeEntityRecord canonical)
+    {
+        EnsureNotDisposed();
+        ArgumentNullException.ThrowIfNull(canonical);
+        if (!Entities.RemoveActive(canonical))
+            return false;
+
+        Entities.AdvanceLifetimeMutation(canonical.ServerGuid);
+        PublishEntity(RuntimeEntityChange.Deleted, canonical);
+        return true;
+    }
+
     /// <summary>
-    /// Accepts the exact DeleteObject generation without yet publishing the
+    /// Accepts and retires the exact canonical DeleteObject generation without
-    /// retained-object removal. This split lets the graphical host retire the
+    /// yet publishing the retained-object removal. This split lets a graphical
-    /// active identity first, matching the established reentrant callback
+    /// host tear down the exact retired projection before completing the
-    /// order, while Runtime remains the only freshness authority.
+    /// retained-object mutation while Runtime remains the only freshness,
+    /// identity, and canonical-lifetime authority.
     /// </summary>
     public bool TryAcceptDelete(
         DeleteObject.Parsed delete,
         bool isLocalPlayer,
+        bool removeRetainedObject,
         out RuntimeEntityDeleteAcceptance acceptance)
     {
+        EnsureNotDisposed();
         if (!Entities.TryDelete(delete, isLocalPlayer))
         {
             acceptance = null!;
             return false;
         }
 
-        acceptance = new RuntimeEntityDeleteAcceptance(this, delete);
+        Entities.AdvanceLifetimeMutation(delete.Guid);
+        Entities.ParentAttachments.DeleteGeneration(
+            delete.Guid,
+            delete.InstanceSequence);
+
+        RuntimeEntityRecord? retiredCanonical = null;
+        if (Entities.TryGetActive(
+                delete.Guid,
+                out RuntimeEntityRecord active)
+            && active.Incarnation == delete.InstanceSequence
+            && Entities.RemoveActive(active))
+        {
+            retiredCanonical = active;
+            PublishEntity(
+                removeRetainedObject
+                    ? RuntimeEntityChange.Deleted
+                    : RuntimeEntityChange.Withdrawn,
+                active);
+        }
+
+        acceptance = new RuntimeEntityDeleteAcceptance(
+            this,
+            delete,
+            retiredCanonical,
+            removeRetainedObject);
         return true;
     }
 
@@ -104,6 +754,7 @@ public sealed class RuntimeEntityObjectLifetime
     public void CompleteAcceptedDelete(
         RuntimeEntityDeleteAcceptance acceptance)
     {
+        EnsureNotDisposed();
         ArgumentNullException.ThrowIfNull(acceptance);
         if (!ReferenceEquals(acceptance.Owner, this))
         {
@@ -117,6 +768,7 @@ public sealed class RuntimeEntityObjectLifetime
         }
 
         acceptance.Completed = true;
+        if (acceptance.RemoveRetainedObject)
             ObjectTableWiring.ApplyEntityDelete(Objects, acceptance.Delete);
     }
 
@@ -124,12 +776,124 @@ public sealed class RuntimeEntityObjectLifetime
     /// Applies a delete accepted by the dormant exact-incarnation owner after
     /// the active Runtime directory correctly reports no live record.
     /// </summary>
-    public void ApplyAcceptedDormantDelete(DeleteObject.Parsed delete) =>
+    public void ApplyAcceptedDormantDelete(DeleteObject.Parsed delete)
+    {
+        EnsureNotDisposed();
         ObjectTableWiring.ApplyEntityDelete(Objects, delete);
+    }
 
     /// <summary>
     /// Clears retained object state at the Runtime-owned reset stage. App
     /// projection teardown remains a later acknowledged stage.
     /// </summary>
-    public void ClearObjects() => Objects.Clear();
+    public void ClearObjects()
+    {
+        EnsureNotDisposed();
+        Objects.Clear();
+    }
+
+    public IReadOnlyList<RuntimeEntityRecord> BeginSessionClear()
+    {
+        EnsureNotDisposed();
+        if (_sessionClearInProgress)
+            return Array.Empty<RuntimeEntityRecord>();
+
+        _sessionClearInProgress = true;
+        Entities.BeginSessionClear();
+        RuntimeEntityRecord[] retired = Entities.ActiveRecords.ToArray();
+        foreach (RuntimeEntityRecord canonical in retired)
+        {
+            if (!Entities.RemoveActive(canonical))
+                continue;
+            PublishEntity(RuntimeEntityChange.Deleted, canonical);
+        }
+        return retired;
+    }
+
+    public bool CompleteSessionClearIfConverged()
+    {
+        EnsureNotDisposed();
+        if (!_sessionClearInProgress
+            || !Entities.CompleteSessionClearIfConverged())
+        {
+            return false;
+        }
+
+        _sessionClearInProgress = false;
+        return true;
+    }
+
+    public void Dispose()
+    {
+        if (_disposed)
+            return;
+        _disposed = true;
+        Events.Dispose();
+    }
+
+    private bool CommitPositionChannelUpdate(
+        bool applied,
+        uint guid,
+        WorldSession.EntitySpawn accepted,
+        Action<RuntimeEntityRecord>? acknowledgeProjection)
+    {
+        if (!applied
+            || !Entities.TryGetActive(
+                guid,
+                out RuntimeEntityRecord canonical))
+        {
+            return applied;
+        }
+
+        Entities.RefreshSnapshot(canonical, accepted);
+        Entities.AdvancePositionAuthority(canonical);
+        acknowledgeProjection?.Invoke(canonical);
+        if (!Entities.IsCurrent(canonical))
+            return false;
+        PublishEntity(RuntimeEntityChange.Updated, canonical);
+        return Entities.IsCurrent(canonical);
+    }
+
+    private void PublishEntity(
+        RuntimeEntityChange change,
+        RuntimeEntityRecord canonical) =>
+        Events.PublishEntity(change, canonical);
+
+    private void EnsureNotDisposed() =>
+        ObjectDisposedException.ThrowIf(_disposed, this);
+
+    private static Exception? Combine(
+        Exception? first,
+        Exception? second) =>
+        first is null
+            ? second
+            : second is null
+                ? first
+                : new AggregateException(first, second);
+
+    private static InboundCreateResult SupersededCreateResult() => new(
+        CreateObjectTimestampDisposition.StaleGeneration,
+        default,
+        null,
+        default);
+
+    private bool IsCurrentOperation(
+        uint guid,
+        RuntimeEntityRecord canonical,
+        ulong sessionVersion,
+        ulong operationVersion) =>
+        Entities.SessionLifetimeVersion == sessionVersion
+        && Entities.CurrentLifetimeMutation(guid) == operationVersion
+        && Entities.IsCurrent(canonical);
+
+    private RuntimeEntityRegistrationResult SupersededRegistration(
+        uint guid,
+        bool replacedExistingGeneration) =>
+        new(
+            SupersededCreateResult(),
+            Entities.TryGetActive(guid, out RuntimeEntityRecord current)
+                ? current
+                : null,
+            LogicalRegistrationCreated: false,
+            ReplacedExistingGeneration: replacedExistingGeneration);
 }

src/AcDream.Runtime/Entities/RuntimeEntityObjectViews.cs

@@ -0,0 +1,151 @@
+using AcDream.Core.Items;
+using AcDream.Core.Net.Messages;
+using AcDream.Core.Physics;
+using System.Numerics;
+
+namespace AcDream.Runtime.Entities;
+
+/// <summary>
+/// Allocation-free borrowed views over the canonical entity/object lifetime.
+/// These views contain no App projection or backend state.
+/// </summary>
+internal sealed class RuntimeEntityObjectViews
+{
+    public RuntimeEntityObjectViews(
+        RuntimeEntityDirectory entities,
+        ClientObjectTable objects)
+    {
+        Entities = new EntityView(
+            entities ?? throw new ArgumentNullException(nameof(entities)));
+        Inventory = new InventoryView(
+            entities,
+            objects ?? throw new ArgumentNullException(nameof(objects)));
+    }
+
+    public IRuntimeEntityView Entities { get; }
+    public IRuntimeInventoryView Inventory { get; }
+
+    internal static RuntimeEntitySnapshot Snapshot(RuntimeEntityRecord record)
+    {
+        ArgumentNullException.ThrowIfNull(record);
+        uint localEntityId = record.LocalEntityId
+            ?? throw new InvalidOperationException(
+                $"Canonical entity 0x{record.ServerGuid:X8}/{record.Incarnation} has no Runtime identity.");
+        return new RuntimeEntitySnapshot(
+            new RuntimeEntityIdentity(
+                record.ServerGuid,
+                localEntityId,
+                record.Incarnation),
+            record.FullCellId,
+            (uint)record.FinalPhysicsState,
+            ConvertPosition(record.Snapshot.Position));
+    }
+
+    private static Position? ConvertPosition(
+        CreateObject.ServerPosition? position) =>
+        position is not { } value
+            ? null
+            : new Position(
+                value.LandblockId,
+                new Vector3(
+                    value.PositionX,
+                    value.PositionY,
+                    value.PositionZ),
+                new Quaternion(
+                    value.RotationX,
+                    value.RotationY,
+                    value.RotationZ,
+                    value.RotationW));
+
+    internal static RuntimeInventoryItemSnapshot Snapshot(
+        ClientObject item,
+        RuntimeEntityDirectory entities,
+        ushort? exactGeneration = null)
+    {
+        ArgumentNullException.ThrowIfNull(item);
+        ushort incarnation = exactGeneration
+            ?? (entities.TryGetActive(
+                    item.ObjectId,
+                    out RuntimeEntityRecord canonical)
+                ? canonical.Incarnation
+                : (ushort)0);
+        return new RuntimeInventoryItemSnapshot(
+            item.ObjectId,
+            incarnation,
+            item.Name,
+            item.ContainerId,
+            item.ContainerSlot,
+            item.WielderId,
+            (uint)item.CurrentlyEquippedLocation,
+            item.StackSize,
+            item.Value);
+    }
+
+    private sealed class EntityView(RuntimeEntityDirectory owner)
+        : IRuntimeEntityView
+    {
+        public int Count => owner.Count;
+
+        public bool TryGet(
+            uint serverGuid,
+            out RuntimeEntitySnapshot entity)
+        {
+            if (owner.TryGetActive(
+                    serverGuid,
+                    out RuntimeEntityRecord record))
+            {
+                entity = Snapshot(record);
+                return true;
+            }
+
+            entity = default;
+            return false;
+        }
+
+        public void Visit(IRuntimeEntityVisitor visitor)
+        {
+            ArgumentNullException.ThrowIfNull(visitor);
+            foreach (RuntimeEntityRecord record in owner.ActiveRecords)
+            {
+                RuntimeEntitySnapshot entity = Snapshot(record);
+                visitor.Visit(in entity);
+            }
+        }
+    }
+
+    private sealed class InventoryView(
+        RuntimeEntityDirectory entities,
+        ClientObjectTable owner)
+        : IRuntimeInventoryView
+    {
+        public int ObjectCount => owner.ObjectCount;
+        public int ContainerCount => owner.ContainerCount;
+
+        public bool TryGet(
+            uint objectId,
+            out RuntimeInventoryItemSnapshot item)
+        {
+            ClientObject? found = owner.Get(objectId);
+            if (found is not null)
+            {
+                item = Snapshot(found, entities);
+                return true;
+            }
+
+            item = default;
+            return false;
+        }
+
+        public void Visit(IRuntimeInventoryVisitor visitor)
+        {
+            ArgumentNullException.ThrowIfNull(visitor);
+            foreach (ClientObject item in owner.Objects)
+            {
+                RuntimeInventoryItemSnapshot snapshot = Snapshot(
+                    item,
+                    entities);
+                visitor.Visit(in snapshot);
+            }
+        }
+    }
+}

src/AcDream.Runtime/GameRuntimeEvents.cs

@@ -225,12 +225,26 @@ public sealed class RuntimeTraceRecorder : IRuntimeEventObserver
 /// <summary>Monotonic sequence owner for one runtime instance.</summary>
 public sealed class RuntimeEventSequencer
 {
+    private RuntimeGenerationToken _generation;
+    private bool _hasGeneration;
     private ulong _sequence;
 
     public RuntimeEventStamp Next(
         RuntimeGenerationToken generation,
-        ulong frameNumber) =>
+        ulong frameNumber)
-        new(generation, checked(++_sequence), frameNumber);
+    {
+        if (!_hasGeneration || generation != _generation)
+        {
+            _generation = generation;
+            _sequence = 0;
+            _hasGeneration = true;
+        }
+
+        return new RuntimeEventStamp(
+            generation,
+            checked(++_sequence),
+            frameNumber);
+    }
 
     public ulong LastSequence => _sequence;
 }

src/AcDream.Runtime/GameRuntimeViews.cs

@@ -11,10 +11,7 @@ public readonly record struct RuntimeEntitySnapshot(
     RuntimeEntityIdentity Identity,
     uint CellId,
     uint PhysicsState,
-    Position? Position,
+    Position? Position);
-    bool IsMaterialized,
-    bool IsSpatiallyVisible,
-    bool IsHydrated);
 
 public interface IRuntimeEntityVisitor
 {
@@ -25,8 +22,6 @@ public interface IRuntimeEntityView
 {
     int Count { get; }
 
-    int MaterializedCount { get; }
-
     bool TryGet(uint serverGuid, out RuntimeEntitySnapshot entity);
 
     /// <summary>

tests/AcDream.App.Tests/Physics/LiveEntityInboundAuthorityGateTests.cs

@@ -251,7 +251,7 @@ public sealed class LiveEntityInboundAuthorityGateTests
         Assert.True(timestampAccepted);
         Assert.True(runtime.TryGetCanonical(Guid, out RuntimeEntityRecord replacement));
         Assert.Equal((ushort)7, replacement.Incarnation);
-        Assert.Null(replacement.LocalEntityId);
+        Assert.NotNull(replacement.LocalEntityId);
         Assert.False(runtime.TryGetRecord(Guid, out _));
     }
 

tests/AcDream.App.Tests/Rendering/GameWindowSlice8BoundaryTests.cs

@@ -469,6 +469,7 @@ public sealed class GameWindowSlice8BoundaryTests
             "new ResourceShutdownStage(\"frame borrowers\"",
             "new ResourceShutdownStage(\"session dependents\"",
             "new ResourceShutdownStage(\"live entities\"",
+            "new ResourceShutdownStage(\"runtime entity/object stream\"",
             "new ResourceShutdownStage(\"effect dispatch edges\"",
             "new ResourceShutdownStage(\"live entity dependents\"",
             "new ResourceShutdownStage(\"submitted GPU work\"",

tests/AcDream.App.Tests/Runtime/CurrentGameRuntimeAdapterTests.cs

@@ -17,6 +17,7 @@ using AcDream.Core.Physics;
 using AcDream.Core.Selection;
 using AcDream.Core.World;
 using AcDream.Runtime;
+using AcDream.Runtime.Entities;
 using AcDream.Runtime.Session;
 using AcDream.UI.Abstractions;
 using AcDream.UI.Abstractions.Input;
@@ -174,6 +175,172 @@ public sealed class CurrentGameRuntimeAdapterTests
         Assert.Equal(RuntimeLifecycleState.Stopped, harness.Runtime.Lifecycle.State);
     }
 
+    [Fact]
+    public void DirectAndGraphicalHosts_ProduceIdenticalEntityObjectTrace()
+    {
+        WorldSession.EntitySpawn spawn =
+            Spawn(Harness.TargetGuid, instance: 7, cell: 0x12340001u);
+        var direct = new RuntimeEntityObjectLifetime();
+        direct.BindEventContext(static () => default, static () => 0UL);
+        var directTrace = new EntityObjectTrace();
+        using IDisposable directSubscription =
+            direct.Events.Subscribe(directTrace);
+
+        RuntimeEntityRegistrationResult directRegistration =
+            direct.RegisterEntity(spawn);
+        RuntimeEntityRecord directCanonical =
+            Assert.IsType<RuntimeEntityRecord>(directRegistration.Canonical);
+        direct.Objects.AddOrUpdate(Object(spawn));
+        direct.Objects.MoveItem(
+            spawn.Guid,
+            Harness.PlayerGuid,
+            newSlot: 3);
+        var vector = new VectorUpdate.Parsed(
+            spawn.Guid,
+            new Vector3(1f, 2f, 3f),
+            new Vector3(0f, 0f, 0.25f),
+            spawn.InstanceSequence,
+            VectorSequence: 2);
+        Assert.True(direct.TryApplyVector(
+            vector,
+            acknowledgeProjection: null,
+            out _));
+        var state = new SetState.Parsed(
+            spawn.Guid,
+            (uint)(PhysicsStateFlags.ReportCollisions
+                | PhysicsStateFlags.Hidden),
+            spawn.InstanceSequence,
+            StateSequence: 2);
+        Assert.True(direct.TryApplyState(
+            state,
+            acknowledgeProjection: null,
+            out _,
+            out _));
+        WorldSession.EntityPositionUpdate position =
+            Position(spawn.Guid, spawn.InstanceSequence);
+        Assert.True(direct.TryApplyPosition(
+            position,
+            isLocalPlayer: false,
+            forcePositionRotation: null,
+            currentLocalVelocity: null,
+            projectionRequiresTeleportHook: false,
+            acknowledgeProjection: null,
+            out _,
+            out _,
+            out _));
+        Assert.True(direct.TryApplyPickup(
+            new PickupEvent.Parsed(
+                spawn.Guid,
+                spawn.InstanceSequence,
+                PositionSequence: 3),
+            acknowledgeProjection: null,
+            out _));
+        Assert.True(direct.TryAcceptDelete(
+            new DeleteObject.Parsed(spawn.Guid, spawn.InstanceSequence),
+            isLocalPlayer: false,
+            removeRetainedObject: true,
+            out RuntimeEntityDeleteAcceptance directDelete));
+        direct.CompleteAcceptedDelete(directDelete);
+        Assert.Null(direct.RetireCanonicalOnly(directCanonical));
+
+        using var graphical = new Harness();
+        var graphicalTrace = new EntityObjectTrace();
+        using IDisposable graphicalSubscription =
+            graphical.EntityObjects.Events.Subscribe(graphicalTrace);
+        _ = graphical.Entities.RegisterAndMaterializeProjection(spawn);
+        graphical.Objects.AddOrUpdate(Object(spawn));
+        graphical.Objects.MoveItem(
+            spawn.Guid,
+            Harness.PlayerGuid,
+            newSlot: 3);
+        Assert.True(graphical.Entities.TryApplyVector(vector, out _));
+        Assert.True(graphical.Entities.TryApplyState(state, out _, out _));
+        Assert.True(graphical.Entities.TryApplyPosition(
+            position,
+            isLocalPlayer: false,
+            forcePositionRotation: null,
+            currentLocalVelocity: null,
+            out _,
+            out _,
+            out _));
+        Assert.True(graphical.Entities.TryApplyPickup(
+            new PickupEvent.Parsed(
+                spawn.Guid,
+                spawn.InstanceSequence,
+                PositionSequence: 3),
+            out _));
+        Assert.True(graphical.Entities.UnregisterLiveEntity(
+            new DeleteObject.Parsed(spawn.Guid, spawn.InstanceSequence),
+            isLocalPlayer: false,
+            removeRetainedObject: true));
+
+        Assert.Equal(directTrace.Entries, graphicalTrace.Entries);
+        Assert.Equal(0, direct.Entities.Count);
+        Assert.Equal(0, direct.Objects.ObjectCount);
+        Assert.Equal(0, graphical.EntityObjects.Entities.Count);
+        Assert.Equal(0, graphical.Objects.ObjectCount);
+    }
+
+    [Fact]
+    public void GraphicalObserverFailure_DoesNotStarveLaterObserverOrOwner()
+    {
+        using var harness = new Harness();
+        var throwing = new ThrowingEntityObserver();
+        var recording = new RuntimeTraceRecorder();
+        IDisposable first = harness.Runtime.Subscribe(throwing);
+        IDisposable second = harness.Runtime.Subscribe(recording);
+
+        LiveEntityRecord record =
+            harness.Entities.RegisterAndMaterializeProjection(Spawn(
+                Harness.TargetGuid,
+                instance: 4,
+                cell: 0x12340001u));
+
+        Assert.True(harness.EntityObjects.Entities.IsCurrent(record.Canonical));
+        Assert.Contains(
+            recording.Entries,
+            entry => entry.Kind == RuntimeTraceKind.Entity
+                && entry.PrimaryObjectId == Harness.TargetGuid);
+        Assert.Equal(1, harness.EntityObjects.Events.SubscriberCount);
+        Assert.Equal(0, harness.EntityObjects.Events.DispatchFailureCount);
+
+        first.Dispose();
+        second.Dispose();
+        Assert.Equal(0, harness.EntityObjects.Events.SubscriberCount);
+    }
+
+    private static ClientObject Object(WorldSession.EntitySpawn spawn) => new()
+    {
+        ObjectId = spawn.Guid,
+        Name = spawn.Name ?? string.Empty,
+        StackSize = 4,
+        Value = 25,
+        ContainerId = Harness.PlayerGuid,
+        ContainerSlot = 2,
+    };
+
+    private static WorldSession.EntityPositionUpdate Position(
+        uint guid,
+        ushort instance) =>
+        new(
+            guid,
+            new CreateObject.ServerPosition(
+                0x12350001u,
+                30f,
+                40f,
+                8f,
+                1f,
+                0f,
+                0f,
+                0f),
+            Velocity: new Vector3(1f, 2f, 3f),
+            PlacementId: null,
+            IsGrounded: true,
+            InstanceSequence: instance,
+            PositionSequence: 2,
+            TeleportSequence: 0,
+            ForcePositionSequence: 0);
+
     private sealed class Harness : IDisposable
     {
         public const uint PlayerGuid = 0x50000002u;
@@ -185,10 +352,12 @@ public sealed class CurrentGameRuntimeAdapterTests
         public Harness()
         {
             Identity = new LocalPlayerIdentityState();
-            Entities = LiveEntityRuntimeFixture.Create(
+            EntityObjects = new RuntimeEntityObjectLifetime();
+            Entities = new LiveEntityRuntime(
                 new GpuWorldState(),
-                new NoopEntityResources());
+                new NoopEntityResources(),
-            Objects = new ClientObjectTable();
+                EntityObjects);
+            Objects = EntityObjects.Objects;
             Chat = new ChatLog();
             Selection = new SelectionState();
             MovementInput = new DispatcherMovementInputSource();
@@ -233,7 +402,7 @@ public sealed class CurrentGameRuntimeAdapterTests
                 Commands,
                 Identity,
                 Entities,
-                Objects,
+                EntityObjects,
                 Chat,
                 new LocalPlayerControllerSlot(),
                 WorldReveal,
@@ -246,6 +415,7 @@ public sealed class CurrentGameRuntimeAdapterTests
 
         public RuntimeOptions Options { get; }
         public LocalPlayerIdentityState Identity { get; }
+        public RuntimeEntityObjectLifetime EntityObjects { get; }
         public LiveEntityRuntime Entities { get; }
         public ClientObjectTable Objects { get; }
         public ChatLog Chat { get; }
@@ -541,6 +711,64 @@ public sealed class CurrentGameRuntimeAdapterTests
             ActivationType activation) => false;
     }
 
+    private sealed class EntityObjectTrace : IRuntimeEntityObjectObserver
+    {
+        public List<string> Entries { get; } = [];
+
+        public void OnEntity(in RuntimeEntityDelta delta) =>
+            Entries.Add(
+                $"E:{delta.Stamp.Sequence}:{delta.Change}:"
+                + $"{delta.Entity.Identity.ServerGuid:X8}:"
+                + $"{delta.Entity.Identity.LocalEntityId}:"
+                + $"{delta.Entity.Identity.Incarnation}:"
+                + $"{delta.Entity.CellId:X8}:"
+                + $"{delta.Entity.PhysicsState:X8}:"
+                + $"{delta.Entity.Position?.ObjCellId:X8}:"
+                + $"{delta.Entity.Position?.Frame.Origin.X}:"
+                + $"{delta.Entity.Position?.Frame.Origin.Y}:"
+                + $"{delta.Entity.Position?.Frame.Origin.Z}");
+
+        public void OnInventory(in RuntimeInventoryDelta delta) =>
+            Entries.Add(
+                $"I:{delta.Stamp.Sequence}:{delta.Change}:"
+                + $"{delta.Item.ObjectId:X8}:"
+                + $"{delta.Item.Incarnation}:"
+                + $"{delta.Item.ContainerId:X8}:"
+                + $"{delta.Item.ContainerSlot}:"
+                + $"{delta.Item.StackSize}:"
+                + $"{delta.Item.Value}");
+    }
+
+    private sealed class ThrowingEntityObserver : IRuntimeEventObserver
+    {
+        public void OnLifecycle(in RuntimeLifecycleDelta delta)
+        {
+        }
+
+        public void OnCommand(in RuntimeCommandDelta delta)
+        {
+        }
+
+        public void OnEntity(in RuntimeEntityDelta delta) =>
+            throw new InvalidOperationException("observer");
+
+        public void OnInventory(in RuntimeInventoryDelta delta)
+        {
+        }
+
+        public void OnChat(in RuntimeChatDelta delta)
+        {
+        }
+
+        public void OnMovement(in RuntimeMovementDelta delta)
+        {
+        }
+
+        public void OnPortal(in RuntimePortalDelta delta)
+        {
+        }
+    }
+
     private sealed class SelectionQuery(uint target) : IWorldSelectionQuery
     {
         public uint? PickAtCursor(bool includeSelf) => target;

tests/AcDream.App.Tests/Streaming/LandblockPresentationPipelineTests.cs

@@ -1168,7 +1168,8 @@ public sealed class LandblockPresentationPipelineTests
             nearRadius: 0,
             farRadius: 0,
             onLandblockLoaded: _ => recoveryCalls++,
-            ensureEnvCellMeshes: _ => replayCalls++);
+            ensureEnvCellMeshes: _ => replayCalls++,
+            workBudgetOptions: GenerousWorkBudget());
 
         Assert.Throws<InvalidOperationException>(() => controller.Tick(0x80, 0x80));
         Assert.True(state.IsNearTier(landblockId));

tests/AcDream.App.Tests/World/LiveEntityHydrationControllerTests.cs

@@ -80,7 +80,7 @@ public sealed class LiveEntityHydrationControllerTests
 
         RuntimeEntityRecord canonical = fixture.Canonical;
         Assert.False(fixture.Runtime.TryGetRecord(Guid, out _));
-        Assert.Null(canonical.LocalEntityId);
+        Assert.NotNull(canonical.LocalEntityId);
         Assert.Equal(0, fixture.Resources.RegisterCount);
         Assert.Empty(fixture.Materializer.Calls);
 
@@ -134,7 +134,7 @@ public sealed class LiveEntityHydrationControllerTests
         fixture.Controller.OnCreate(spawn);
         RuntimeEntityRecord canonical = fixture.Canonical;
         Assert.False(fixture.Runtime.TryGetRecord(Guid, out _));
-        Assert.Null(canonical.LocalEntityId);
+        Assert.NotNull(canonical.LocalEntityId);
 
         Assert.True(fixture.Controller.OnAppearance(ObjDesc(2, 0x04000022u)));
 
@@ -522,7 +522,7 @@ public sealed class LiveEntityHydrationControllerTests
 
         RuntimeEntityRecord canonical = fixture.Canonical;
         Assert.False(fixture.Runtime.TryGetRecord(Guid, out _));
-        Assert.Null(canonical.LocalEntityId);
+        Assert.NotNull(canonical.LocalEntityId);
         Assert.Equal(1, resources.RegisterCount);
         Assert.Equal(1, resources.UnregisterCount);
 
@@ -852,7 +852,7 @@ public sealed class LiveEntityHydrationControllerTests
         RuntimeEntityRecord replacement = fixture.Canonical;
         Assert.Equal((ushort)2, replacement.Generation);
         Assert.Equal("replacement", replacement.Snapshot.Name);
-        Assert.Null(replacement.LocalEntityId);
+        Assert.NotNull(replacement.LocalEntityId);
         Assert.False(fixture.Runtime.TryGetRecord(Guid, out _));
         Assert.Equal(0, fixture.Runtime.PendingTeardownCount);
     }
@@ -1368,7 +1368,7 @@ public sealed class LiveEntityHydrationControllerTests
         fixture.Controller.OnCreate(Spawn(Generation: 1, PositionSequence: 1));
 
         RuntimeEntityRecord canonical = fixture.Canonical;
-        Assert.Null(canonical.LocalEntityId);
+        Assert.NotNull(canonical.LocalEntityId);
         Assert.False(fixture.Runtime.TryGetRecord(Guid, out _));
         Assert.Equal(0, fixture.Resources.RegisterCount);
 

tests/AcDream.App.Tests/World/LiveEntityPhysicsHostOwnershipTests.cs

@@ -312,7 +312,7 @@ public sealed class LiveEntityPhysicsHostOwnershipTests
 
         Assert.True(runtime.TryGetCanonical(guid, out var replacement));
         Assert.Equal((ushort)2, replacement.Incarnation);
-        Assert.Null(replacement.LocalEntityId);
+        Assert.NotNull(replacement.LocalEntityId);
         Assert.Null(replacement.PhysicsBody);
         Assert.False(runtime.TryGetRecord(guid, out _));
         Assert.Null(retired.RemoteMotionRuntime);

tests/AcDream.App.Tests/World/LiveEntityRuntimeTests.cs

@@ -1656,7 +1656,7 @@ public sealed class LiveEntityRuntimeTests
 
         Assert.False(runtime.TryGetRecord(spawn.Guid, out _));
         RuntimeEntityRecord canonical = CurrentCanonical(runtime, spawn.Guid);
-        Assert.Null(canonical.LocalEntityId);
+        Assert.NotNull(canonical.LocalEntityId);
         Assert.Equal(0, runtime.MaterializedCount);
         Assert.Empty(runtime.VisibleRecords);
         Assert.Empty(spatial.Entities);
@@ -1901,7 +1901,7 @@ public sealed class LiveEntityRuntimeTests
         Assert.NotNull(replacement.PriorGenerationCleanupFailure);
         RuntimeEntityRecord canonical = CurrentCanonical(runtime, guid);
         Assert.Equal((ushort)2, canonical.Generation);
-        Assert.Null(canonical.LocalEntityId);
+        Assert.NotNull(canonical.LocalEntityId);
         Assert.False(runtime.TryGetRecord(guid, out _));
         WorldEntity installed = runtime.MaterializeLiveEntity(
             guid,
@@ -2459,7 +2459,7 @@ public sealed class LiveEntityRuntimeTests
                 && exception.Message.Contains("active logical-lifetime transition", StringComparison.Ordinal));
         RuntimeEntityRecord current = CurrentCanonical(runtime, guid);
         Assert.Equal((ushort)2, current.Generation);
-        Assert.Null(current.LocalEntityId);
+        Assert.NotNull(current.LocalEntityId);
         Assert.False(runtime.TryGetRecord(guid, out _));
         Assert.Empty(spatial.Entities);
         Assert.DoesNotContain(
@@ -2493,7 +2493,7 @@ public sealed class LiveEntityRuntimeTests
         Assert.False(outer.LogicalRegistrationCreated);
         RuntimeEntityRecord current = CurrentCanonical(runtime, guid);
         Assert.Equal((ushort)3, current.Generation);
-        Assert.Null(current.LocalEntityId);
+        Assert.NotNull(current.LocalEntityId);
         Assert.False(runtime.TryGetRecord(guid, out _));
         Assert.Empty(spatial.Entities);
         Assert.Equal(1, resources.RegisterCount);
@@ -2524,8 +2524,8 @@ public sealed class LiveEntityRuntimeTests
         Assert.True(outer.LogicalRegistrationCreated);
         RuntimeEntityRecord replacement = CurrentCanonical(runtime, guid);
         Assert.Equal((ushort)2, replacement.Generation);
-        Assert.Null(replacement.LocalEntityId);
+        Assert.NotNull(replacement.LocalEntityId);
-        Assert.Null(CurrentCanonical(runtime, unrelatedGuid).LocalEntityId);
+        Assert.NotNull(CurrentCanonical(runtime, unrelatedGuid).LocalEntityId);
         Assert.False(runtime.TryGetRecord(guid, out _));
         Assert.False(runtime.TryGetRecord(unrelatedGuid, out _));
         Assert.Equal(2, runtime.Count);
@@ -2587,7 +2587,7 @@ public sealed class LiveEntityRuntimeTests
         Assert.False(outer.LogicalRegistrationCreated);
         RuntimeEntityRecord current = CurrentCanonical(runtime, guid);
         Assert.Equal((ushort)3, current.Generation);
-        Assert.Null(current.LocalEntityId);
+        Assert.NotNull(current.LocalEntityId);
         Assert.False(runtime.TryGetRecord(guid, out _));
         Assert.Equal(1, resources.RegisterCount);
         Assert.Equal(1, resources.UnregisterCount);
@@ -2619,7 +2619,7 @@ public sealed class LiveEntityRuntimeTests
                 && exception.Message == "old incarnation cleanup failed");
         RuntimeEntityRecord current = CurrentCanonical(runtime, guid);
         Assert.Equal((ushort)3, current.Generation);
-        Assert.Null(current.LocalEntityId);
+        Assert.NotNull(current.LocalEntityId);
         Assert.False(runtime.TryGetRecord(guid, out _));
         Assert.Equal(1, resources.RegisterCount);
         Assert.Equal(1, resources.UnregisterCount);
@@ -2671,7 +2671,7 @@ public sealed class LiveEntityRuntimeTests
         Assert.Contains("atomic resource registration", error.Message, StringComparison.Ordinal);
         RuntimeEntityRecord current = CurrentCanonical(runtime, guid);
         Assert.Equal((ushort)1, current.Generation);
-        Assert.Null(current.LocalEntityId);
+        Assert.NotNull(current.LocalEntityId);
         Assert.False(runtime.TryGetRecord(guid, out _));
         Assert.Equal(1, resources.RegisterCount);
         Assert.Equal(1, resources.UnregisterCount);
@@ -2695,7 +2695,7 @@ public sealed class LiveEntityRuntimeTests
 
         Assert.Contains("atomic resource registration", error.Message, StringComparison.Ordinal);
         RuntimeEntityRecord current = CurrentCanonical(runtime, guid);
-        Assert.Null(current.LocalEntityId);
+        Assert.NotNull(current.LocalEntityId);
         Assert.False(runtime.TryGetRecord(guid, out _));
         Assert.Equal(1, resources.RegisterCount);
         Assert.Equal(1, resources.UnregisterCount);

tests/AcDream.App.Tests/World/RuntimeEntityOwnershipTests.cs

@@ -4,8 +4,11 @@ using AcDream.App.Rendering;
 using AcDream.App.Rendering.Scene;
 using AcDream.App.Rendering.Vfx;
 using AcDream.App.Rendering.Wb;
+using AcDream.App.Runtime;
 using AcDream.App.Streaming;
 using AcDream.App.World;
+using AcDream.Core.Items;
+using AcDream.Runtime;
 using AcDream.Runtime.Entities;
 
 namespace AcDream.App.Tests.World;
@@ -230,6 +233,46 @@ public sealed class RuntimeEntityOwnershipTests
             property => IsPresentationType(property.PropertyType));
     }
 
+    [Fact]
+    public void CurrentRuntimeAdapters_DoNotRetainEntityOrInventoryMirrors()
+    {
+        FieldInfo[] viewFields = typeof(CurrentGameRuntimeViewAdapter)
+            .GetFields(BindingFlags.Instance | BindingFlags.NonPublic);
+        Assert.Contains(
+            viewFields,
+            field => field.FieldType == typeof(IRuntimeEntityView));
+        Assert.Contains(
+            viewFields,
+            field => field.FieldType == typeof(IRuntimeInventoryView));
+        Assert.DoesNotContain(
+            typeof(CurrentGameRuntimeViewAdapter).GetNestedTypes(
+                BindingFlags.NonPublic),
+            type => type.Name is "EntityView" or "InventoryView");
+
+        FieldInfo[] eventFields = typeof(CurrentGameRuntimeEventAdapter)
+            .GetFields(BindingFlags.Instance | BindingFlags.NonPublic);
+        Assert.DoesNotContain(
+            eventFields,
+            field => field.FieldType == typeof(LiveEntityRuntime)
+                || field.FieldType == typeof(ClientObjectTable)
+                || field.FieldType == typeof(RuntimeEventSequencer));
+        Assert.Contains(
+            eventFields,
+            field => field.FieldType
+                == typeof(RuntimeEntityObjectLifetime));
+
+        string root = FindRepositoryRoot();
+        string liveSource = File.ReadAllText(Path.Combine(
+            root,
+            "src",
+            "AcDream.App",
+            "World",
+            "LiveEntityRuntime.cs"));
+        Assert.DoesNotContain("_entityObjects.PublishEntity", liveSource);
+        Assert.DoesNotContain("_directory.TryApply", liveSource);
+        Assert.DoesNotContain("_directory.RemoveActive", liveSource);
+    }
+
     private static bool IsPresentationType(Type type)
     {
         string? ns = type.Namespace;

tests/AcDream.Runtime.Tests/Entities/RuntimeEntityObjectLifetimeTests.cs

@@ -1,6 +1,7 @@
 using AcDream.Core.Net;
 using AcDream.Core.Net.Messages;
 using AcDream.Core.Physics;
+using AcDream.Core.Items;
 using AcDream.Runtime.Entities;
 
 namespace AcDream.Runtime.Tests.Entities;
@@ -120,14 +121,19 @@ public sealed class RuntimeEntityObjectLifetimeTests
         Assert.False(lifetime.TryAcceptDelete(
             new DeleteObject.Parsed(spawn.Guid, 7),
             isLocalPlayer: false,
+            removeRetainedObject: true,
             out _));
         Assert.NotNull(lifetime.Objects.Get(spawn.Guid));
 
         Assert.True(lifetime.TryAcceptDelete(
             new DeleteObject.Parsed(spawn.Guid, 6),
             isLocalPlayer: false,
+            removeRetainedObject: true,
             out RuntimeEntityDeleteAcceptance accepted));
+        Assert.Same(canonical, accepted.RetiredCanonical);
+        Assert.False(lifetime.Entities.TryGetActive(spawn.Guid, out _));
         lifetime.CompleteAcceptedDelete(accepted);
+        Assert.Null(lifetime.RetireCanonicalOnly(canonical));
         Assert.Null(lifetime.Objects.Get(spawn.Guid));
     }
 
@@ -146,6 +152,7 @@ public sealed class RuntimeEntityObjectLifetimeTests
         Assert.True(owner.TryAcceptDelete(
             new DeleteObject.Parsed(spawn.Guid, spawn.InstanceSequence),
             isLocalPlayer: false,
+            removeRetainedObject: true,
             out RuntimeEntityDeleteAcceptance acceptance));
 
         Assert.Throws<InvalidOperationException>(
@@ -175,6 +182,509 @@ public sealed class RuntimeEntityObjectLifetimeTests
         Assert.Same(canonical, retained);
     }
 
+    [Fact]
+    public void CanonicalRegistration_IssuesIdentityBeforeAnyProjection()
+    {
+        var lifetime = new RuntimeEntityObjectLifetime();
+        WorldSession.EntitySpawn spawn = Spawn(
+            0x70000010u,
+            4,
+            "direct");
+        RuntimeEntityRecord canonical = Accept(lifetime, spawn);
+
+        Assert.Equal(
+            RuntimeEntityDirectory.FirstLocalEntityId,
+            canonical.LocalEntityId);
+        Assert.True(lifetime.EntityView.TryGet(
+            spawn.Guid,
+            out RuntimeEntitySnapshot snapshot));
+        Assert.Equal(canonical.LocalEntityId, snapshot.Identity.LocalEntityId);
+        Assert.Equal(spawn.InstanceSequence, snapshot.Identity.Incarnation);
+        Assert.Equal(spawn.Position!.Value.LandblockId, snapshot.CellId);
+    }
+
+    [Fact]
+    public void EntityAndInventoryCommits_ShareOnePerGenerationSequence()
+    {
+        var lifetime = new RuntimeEntityObjectLifetime();
+        RuntimeGenerationToken generation = new(8);
+        ulong frame = 20;
+        lifetime.BindEventContext(() => generation, () => frame);
+        var observer = new RecordingObserver();
+        using IDisposable subscription = lifetime.Events.Subscribe(observer);
+        WorldSession.EntitySpawn spawn = Spawn(
+            0x70000011u,
+            2,
+            "ordered");
+        RuntimeEntityRecord canonical =
+            lifetime.RegisterEntity(spawn).Canonical!;
+
+        Assert.True(lifetime.ApplyAcceptedSpawn(
+            canonical,
+            canonical.CreateIntegrationVersion,
+            spawn,
+            replaceGeneration: false));
+        frame++;
+        lifetime.Objects.MoveItem(
+            spawn.Guid,
+            newContainerId: 0x50000001u,
+            newSlot: 3);
+        _ = lifetime.RegisterEntity(spawn);
+
+        Assert.Equal(
+            [
+                (RuntimeTraceKind.Entity, 1UL),
+                (RuntimeTraceKind.Inventory, 2UL),
+                (RuntimeTraceKind.Inventory, 3UL),
+                (RuntimeTraceKind.Entity, 4UL),
+            ],
+            observer.Order);
+        Assert.All(
+            observer.Stamps,
+            stamp => Assert.Equal(generation, stamp.Generation));
+        Assert.Equal(20UL, observer.Stamps[0].FrameNumber);
+        Assert.Equal(21UL, observer.Stamps[^1].FrameNumber);
+
+        generation = new RuntimeGenerationToken(9);
+        lifetime.ClearObjects();
+        Assert.Equal(1UL, observer.Stamps[^1].Sequence);
+        Assert.Equal(generation, observer.Stamps[^1].Generation);
+    }
+
+    [Fact]
+    public void InventoryView_UsesCanonicalRuntimeIncarnationWithoutApp()
+    {
+        var lifetime = new RuntimeEntityObjectLifetime();
+        WorldSession.EntitySpawn spawn = Spawn(
+            0x70000012u,
+            12,
+            "inventory");
+        RuntimeEntityRecord canonical = Accept(lifetime, spawn);
+        Assert.True(lifetime.ApplyAcceptedSpawn(
+            canonical,
+            canonical.CreateIntegrationVersion,
+            spawn,
+            replaceGeneration: false));
+
+        Assert.True(lifetime.InventoryView.TryGet(
+            spawn.Guid,
+            out RuntimeInventoryItemSnapshot item));
+        Assert.Equal((ushort)12, item.Incarnation);
+        Assert.Equal("inventory", item.Name);
+    }
+
+    [Fact]
+    public void UnknownConfirmedMove_RetainsIdentityAndPlacementInStream()
+    {
+        var lifetime = new RuntimeEntityObjectLifetime();
+        var observer = new RecordingObserver();
+        using IDisposable subscription = lifetime.Events.Subscribe(observer);
+
+        Assert.False(lifetime.Objects.ApplyConfirmedServerMove(
+            0x7000DEADu,
+            newContainerId: 0x50000001u,
+            newWielderId: 0u,
+            newSlot: 7));
+
+        RuntimeInventoryDelta moved = Assert.Single(observer.Inventory);
+        Assert.Equal(RuntimeInventoryChange.Moved, moved.Change);
+        Assert.Equal(0x7000DEADu, moved.Item.ObjectId);
+        Assert.Equal(0x50000001u, moved.Item.ContainerId);
+        Assert.Equal(7, moved.Item.ContainerSlot);
+    }
+
+    [Fact]
+    public void EventSubscriptions_AreExactAndDisposeWithoutRetention()
+    {
+        var lifetime = new RuntimeEntityObjectLifetime();
+        var observer = new RecordingObserver();
+        IDisposable subscription = lifetime.Events.Subscribe(observer);
+
+        Assert.Equal(1, lifetime.Events.SubscriberCount);
+        Assert.Throws<InvalidOperationException>(
+            () => lifetime.Events.Subscribe(observer));
+
+        subscription.Dispose();
+        subscription.Dispose();
+
+        Assert.Equal(0, lifetime.Events.SubscriberCount);
+    }
+
+    [Fact]
+    public void Dispose_DetachesEveryObserverAndRejectsLaterDispatch()
+    {
+        var lifetime = new RuntimeEntityObjectLifetime();
+        var observer = new RecordingObserver();
+        _ = lifetime.Events.Subscribe(observer);
+
+        lifetime.Dispose();
+        lifetime.Dispose();
+
+        Assert.Equal(0, lifetime.Events.SubscriberCount);
+        Assert.Throws<ObjectDisposedException>(
+            () => lifetime.RegisterEntity(
+                Spawn(0x70000018u, 1, "disposed")));
+        lifetime.Objects.AddOrUpdate(new ClientObject
+        {
+            ObjectId = 0x70000019u,
+            Name = "detached",
+        });
+        Assert.Empty(observer.Order);
+    }
+
+    [Fact]
+    public void ObserverFailure_DoesNotInterruptCommitOrLaterObservers()
+    {
+        var lifetime = new RuntimeEntityObjectLifetime();
+        var throwing = new CallbackObserver(
+            onEntity: static _ => throw new InvalidOperationException("observer"));
+        var recording = new RecordingObserver();
+        using IDisposable first = lifetime.Events.Subscribe(throwing);
+        using IDisposable second = lifetime.Events.Subscribe(recording);
+
+        RuntimeEntityRegistrationResult result =
+            lifetime.RegisterEntity(Spawn(0x70000015u, 1, "committed"));
+
+        Assert.True(result.LogicalRegistrationCreated);
+        Assert.NotNull(result.Canonical);
+        Assert.True(lifetime.Entities.IsCurrent(result.Canonical));
+        Assert.Single(recording.Entities);
+        Assert.Equal(RuntimeEntityChange.Registered, recording.Entities[0].Change);
+        Assert.Equal(1, lifetime.Events.DispatchFailureCount);
+        Assert.IsType<InvalidOperationException>(
+            lifetime.Events.LastDispatchFailure);
+    }
+
+    [Fact]
+    public void ObserverMutationDuringDispatch_AffectsOnlyLaterCommits()
+    {
+        var lifetime = new RuntimeEntityObjectLifetime();
+        var removed = new RecordingObserver();
+        var added = new RecordingObserver();
+        IDisposable? removedSubscription = null;
+        IDisposable? addedSubscription = null;
+        bool mutated = false;
+        var mutating = new CallbackObserver(
+            onEntity: _ =>
+            {
+                if (mutated)
+                    return;
+                mutated = true;
+                removedSubscription!.Dispose();
+                addedSubscription = lifetime.Events.Subscribe(added);
+            });
+        using IDisposable first = lifetime.Events.Subscribe(mutating);
+        removedSubscription = lifetime.Events.Subscribe(removed);
+
+        RuntimeEntityRegistrationResult registration =
+            lifetime.RegisterEntity(Spawn(0x70000016u, 1, "first"));
+        _ = lifetime.RegisterEntity(registration.Canonical!.Snapshot);
+
+        Assert.Single(removed.Entities);
+        Assert.Single(added.Entities);
+        Assert.Equal(
+            RuntimeEntityChange.Registered,
+            removed.Entities[0].Change);
+        Assert.Equal(
+            RuntimeEntityChange.Updated,
+            added.Entities[0].Change);
+
+        addedSubscription!.Dispose();
+        Assert.Equal(1, lifetime.Events.SubscriberCount);
+    }
+
+    [Fact]
+    public void DirectDelete_PublishesTerminalEntityBeforeInventoryRemoval()
+    {
+        var lifetime = new RuntimeEntityObjectLifetime();
+        lifetime.BindEventContext(static () => new(4), static () => 11);
+        var observer = new RecordingObserver();
+        using IDisposable subscription = lifetime.Events.Subscribe(observer);
+        WorldSession.EntitySpawn spawn =
+            Spawn(0x70000017u, 5, "delete");
+        RuntimeEntityRegistrationResult registration =
+            lifetime.RegisterEntity(spawn);
+        RuntimeEntityRecord canonical = registration.Canonical!;
+        Assert.True(lifetime.ApplyAcceptedSpawn(
+            canonical,
+            canonical.CreateIntegrationVersion,
+            spawn,
+            replaceGeneration: true));
+
+        Assert.True(lifetime.TryAcceptDelete(
+            new DeleteObject.Parsed(spawn.Guid, spawn.InstanceSequence),
+            isLocalPlayer: false,
+            removeRetainedObject: true,
+            out RuntimeEntityDeleteAcceptance acceptance));
+        lifetime.CompleteAcceptedDelete(acceptance);
+        Assert.Null(lifetime.RetireCanonicalOnly(canonical));
+
+        Assert.Equal(
+            [
+                (RuntimeTraceKind.Entity, 1UL),
+                (RuntimeTraceKind.Inventory, 2UL),
+                (RuntimeTraceKind.Entity, 3UL),
+                (RuntimeTraceKind.Inventory, 4UL),
+            ],
+            observer.Order);
+        Assert.Equal(
+            RuntimeEntityChange.Deleted,
+            observer.Entities[^1].Change);
+        Assert.False(lifetime.EntityView.TryGet(spawn.Guid, out _));
+        Assert.False(lifetime.InventoryView.TryGet(spawn.Guid, out _));
+        Assert.Equal(0, lifetime.Entities.ClaimedLocalIdCount);
+    }
+
+    [Fact]
+    public void SessionClear_SealsOldGenerationAndNextStartsAtOne()
+    {
+        var lifetime = new RuntimeEntityObjectLifetime();
+        RuntimeGenerationToken generation = new(12);
+        lifetime.BindEventContext(() => generation, static () => 30UL);
+        var observer = new RecordingObserver();
+        bool rejectedReentrantCreate = false;
+        var reentrant = new CallbackObserver(
+            onEntity: delta =>
+            {
+                if (delta.Change is not RuntimeEntityChange.Deleted)
+                    return;
+                rejectedReentrantCreate = Assert.Throws<InvalidOperationException>(
+                    () => lifetime.RegisterEntity(
+                        Spawn(delta.Entity.Identity.ServerGuid, 2, "stale")))
+                    is not null;
+            });
+        using IDisposable first = lifetime.Events.Subscribe(reentrant);
+        using IDisposable second = lifetime.Events.Subscribe(observer);
+        WorldSession.EntitySpawn spawn =
+            Spawn(0x70000020u, 1, "old");
+        RuntimeEntityRecord canonical =
+            lifetime.RegisterEntity(spawn).Canonical!;
+        Assert.True(lifetime.ApplyAcceptedSpawn(
+            canonical,
+            canonical.CreateIntegrationVersion,
+            spawn,
+            replaceGeneration: true));
+
+        IReadOnlyList<RuntimeEntityRecord> retired =
+            lifetime.BeginSessionClear();
+        lifetime.ClearObjects();
+        Assert.Null(lifetime.RetireCanonicalOnly(Assert.Single(retired)));
+        Assert.True(lifetime.CompleteSessionClearIfConverged());
+
+        generation = new RuntimeGenerationToken(13);
+        RuntimeEntityRecord replacement =
+            lifetime.RegisterEntity(Spawn(spawn.Guid, 2, "new")).Canonical!;
+
+        Assert.True(rejectedReentrantCreate);
+        Assert.Equal((ushort)2, replacement.Incarnation);
+        Assert.Equal(
+            [
+                (new RuntimeGenerationToken(12), 1UL),
+                (new RuntimeGenerationToken(12), 2UL),
+                (new RuntimeGenerationToken(12), 3UL),
+                (new RuntimeGenerationToken(12), 4UL),
+                (new RuntimeGenerationToken(13), 1UL),
+            ],
+            observer.Stamps
+                .Select(stamp => (stamp.Generation, stamp.Sequence))
+                .ToArray());
+    }
+
+    [Fact]
+    public void RegisterEntity_DirectHostPublishesCompleteGenerationOrder()
+    {
+        var lifetime = new RuntimeEntityObjectLifetime();
+        lifetime.BindEventContext(static () => new(3), static () => 9);
+        var observer = new RecordingObserver();
+        using IDisposable subscription = lifetime.Events.Subscribe(observer);
+        const uint guid = 0x70000013u;
+
+        RuntimeEntityRegistrationResult first =
+            lifetime.RegisterEntity(Spawn(guid, 1, "first"));
+        RuntimeEntityRegistrationResult refresh =
+            lifetime.RegisterEntity(Spawn(guid, 1, "refresh"));
+        RuntimeEntityRegistrationResult replacement =
+            lifetime.RegisterEntity(Spawn(guid, 2, "replacement"));
+
+        Assert.True(first.LogicalRegistrationCreated);
+        Assert.False(refresh.LogicalRegistrationCreated);
+        Assert.True(replacement.ReplacedExistingGeneration);
+        Assert.Equal(
+            [
+                RuntimeEntityChange.Registered,
+                RuntimeEntityChange.Updated,
+                RuntimeEntityChange.Deleted,
+                RuntimeEntityChange.Registered,
+            ],
+            observer.Entities.Select(delta => delta.Change).ToArray());
+        Assert.Equal(
+            [1UL, 2UL, 3UL, 4UL],
+            observer.Entities
+                .Select(delta => delta.Stamp.Sequence)
+                .ToArray());
+        Assert.Equal(
+            (ushort)2,
+            lifetime.EntityView.TryGet(guid, out RuntimeEntitySnapshot current)
+                ? current.Identity.Incarnation
+                : (ushort)0);
+        Assert.Equal(0, lifetime.Entities.PendingTeardownCount);
+    }
+
+    [Fact]
+    public void RegisterEntity_ReentrantNewerGenerationSupersedesOuterCreate()
+    {
+        var lifetime = new RuntimeEntityObjectLifetime();
+        const uint guid = 0x70000014u;
+        _ = lifetime.RegisterEntity(Spawn(guid, 1, "first"));
+        bool nested = false;
+        var observer = new CallbackObserver(
+            onEntity: delta =>
+            {
+                if (nested
+                    || delta.Change is not RuntimeEntityChange.Deleted)
+                {
+                    return;
+                }
+
+                nested = true;
+                _ = lifetime.RegisterEntity(Spawn(guid, 3, "nested"));
+            });
+        using IDisposable subscription = lifetime.Events.Subscribe(observer);
+
+        RuntimeEntityRegistrationResult outer =
+            lifetime.RegisterEntity(Spawn(guid, 2, "outer"));
+
+        Assert.Equal(
+            CreateObjectTimestampDisposition.StaleGeneration,
+            outer.Inbound.Disposition);
+        Assert.False(outer.LogicalRegistrationCreated);
+        Assert.True(lifetime.Entities.TryGetActive(
+            guid,
+            out RuntimeEntityRecord current));
+        Assert.Equal((ushort)3, current.Incarnation);
+        Assert.NotNull(current.LocalEntityId);
+    }
+
+    [Fact]
+    public void RegisterEntity_ReentrantDeleteSupersedesSameGenerationRefresh()
+    {
+        var lifetime = new RuntimeEntityObjectLifetime();
+        const uint guid = 0x70000021u;
+        RuntimeEntityRecord first =
+            lifetime.RegisterEntity(Spawn(guid, 1, "first")).Canonical!;
+        bool deleted = false;
+        var observer = new CallbackObserver(
+            onEntity: delta =>
+            {
+                if (deleted
+                    || delta.Change is not RuntimeEntityChange.Updated)
+                {
+                    return;
+                }
+
+                deleted = lifetime.TryAcceptDelete(
+                    new DeleteObject.Parsed(guid, 1),
+                    isLocalPlayer: false,
+                    removeRetainedObject: false,
+                    out RuntimeEntityDeleteAcceptance acceptance);
+                if (deleted)
+                {
+                    lifetime.CompleteAcceptedDelete(acceptance);
+                    Assert.Null(lifetime.RetireCanonicalOnly(first));
+                }
+            });
+        using IDisposable subscription = lifetime.Events.Subscribe(observer);
+
+        RuntimeEntityRegistrationResult refresh =
+            lifetime.RegisterEntity(Spawn(guid, 1, "refresh"));
+
+        Assert.True(deleted);
+        Assert.Equal(
+            CreateObjectTimestampDisposition.StaleGeneration,
+            refresh.Inbound.Disposition);
+        Assert.Null(refresh.Canonical);
+        Assert.False(lifetime.Entities.TryGetActive(guid, out _));
+    }
+
+    [Fact]
+    public void RegisterEntity_ReentrantReplacementSupersedesInitialCommit()
+    {
+        var lifetime = new RuntimeEntityObjectLifetime();
+        const uint guid = 0x70000022u;
+        bool replaced = false;
+        var observer = new CallbackObserver(
+            onEntity: delta =>
+            {
+                if (replaced
+                    || delta.Change is not RuntimeEntityChange.Registered
+                    || delta.Entity.Identity.Incarnation != 1)
+                {
+                    return;
+                }
+
+                replaced = true;
+                _ = lifetime.RegisterEntity(Spawn(guid, 2, "replacement"));
+            });
+        using IDisposable subscription = lifetime.Events.Subscribe(observer);
+
+        RuntimeEntityRegistrationResult outer =
+            lifetime.RegisterEntity(Spawn(guid, 1, "outer"));
+
+        Assert.True(replaced);
+        Assert.Equal(
+            CreateObjectTimestampDisposition.StaleGeneration,
+            outer.Inbound.Disposition);
+        Assert.False(outer.LogicalRegistrationCreated);
+        Assert.Equal(
+            (ushort)2,
+            Assert.IsType<RuntimeEntityRecord>(outer.Canonical).Incarnation);
+    }
+
+    [Fact]
+    public void AcceptedUpdate_RevalidatesAfterReentrantTerminalObserver()
+    {
+        var lifetime = new RuntimeEntityObjectLifetime();
+        const uint guid = 0x70000023u;
+        RuntimeEntityRecord canonical =
+            lifetime.RegisterEntity(Spawn(guid, 1, "vector")).Canonical!;
+        bool deleted = false;
+        var observer = new CallbackObserver(
+            onEntity: delta =>
+            {
+                if (deleted
+                    || delta.Change is not RuntimeEntityChange.Updated)
+                {
+                    return;
+                }
+
+                deleted = lifetime.TryAcceptDelete(
+                    new DeleteObject.Parsed(guid, 1),
+                    isLocalPlayer: false,
+                    removeRetainedObject: false,
+                    out RuntimeEntityDeleteAcceptance acceptance);
+                if (deleted)
+                {
+                    lifetime.CompleteAcceptedDelete(acceptance);
+                    Assert.Null(lifetime.RetireCanonicalOnly(canonical));
+                }
+            });
+        using IDisposable subscription = lifetime.Events.Subscribe(observer);
+
+        bool remainedCurrent = lifetime.TryApplyVector(
+            new VectorUpdate.Parsed(
+                guid,
+                new System.Numerics.Vector3(1f, 0f, 0f),
+                System.Numerics.Vector3.Zero,
+                InstanceSequence: 1,
+                VectorSequence: 2),
+            acknowledgeProjection: null,
+            out _);
+
+        Assert.True(deleted);
+        Assert.False(remainedCurrent);
+        Assert.False(lifetime.Entities.TryGetActive(guid, out _));
+    }
+
     private static RuntimeEntityRecord Accept(
         RuntimeEntityObjectLifetime lifetime,
         WorldSession.EntitySpawn spawn)
@@ -248,4 +758,38 @@ public sealed class RuntimeEntityObjectLifetimeTests
             PositionSequence: 1,
             Physics: physics);
     }
+
+    private sealed class RecordingObserver : IRuntimeEntityObjectObserver
+    {
+        public List<(RuntimeTraceKind Kind, ulong Sequence)> Order { get; } = [];
+        public List<RuntimeEventStamp> Stamps { get; } = [];
+        public List<RuntimeEntityDelta> Entities { get; } = [];
+        public List<RuntimeInventoryDelta> Inventory { get; } = [];
+
+        public void OnEntity(in RuntimeEntityDelta delta)
+        {
+            Order.Add((RuntimeTraceKind.Entity, delta.Stamp.Sequence));
+            Stamps.Add(delta.Stamp);
+            Entities.Add(delta);
+        }
+
+        public void OnInventory(in RuntimeInventoryDelta delta)
+        {
+            Order.Add((RuntimeTraceKind.Inventory, delta.Stamp.Sequence));
+            Stamps.Add(delta.Stamp);
+            Inventory.Add(delta);
+        }
+    }
+
+    private sealed class CallbackObserver(
+        Action<RuntimeEntityDelta>? onEntity = null,
+        Action<RuntimeInventoryDelta>? onInventory = null)
+        : IRuntimeEntityObjectObserver
+    {
+        public void OnEntity(in RuntimeEntityDelta delta) =>
+            onEntity?.Invoke(delta);
+
+        public void OnInventory(in RuntimeInventoryDelta delta) =>
+            onInventory?.Invoke(delta);
+    }
 }

tests/AcDream.Runtime.Tests/GameRuntimeContractTests.cs

@@ -80,6 +80,21 @@ public sealed class GameRuntimeContractTests
         Assert.Equal(99UL, independent.FrameNumber);
     }
 
+    [Fact]
+    public void EventSequencer_RestartsAtOneForEachSessionGeneration()
+    {
+        var sequencer = new RuntimeEventSequencer();
+
+        RuntimeEventStamp first = sequencer.Next(new(4), 10);
+        RuntimeEventStamp second = sequencer.Next(new(4), 11);
+        RuntimeEventStamp replacement = sequencer.Next(new(5), 12);
+
+        Assert.Equal(1UL, first.Sequence);
+        Assert.Equal(2UL, second.Sequence);
+        Assert.Equal(1UL, replacement.Sequence);
+        Assert.Equal(new RuntimeGenerationToken(5), replacement.Generation);
+    }
+
     [Fact]
     public void TraceRecorderNormalizesTypedDeltasWithoutRetainingOwners()
     {