diff --git a/editor/AGENTS.md b/editor/AGENTS.md
index c0d4a319..23f4c1ab 100644
--- a/editor/AGENTS.md
+++ b/editor/AGENTS.md
@@ -1,319 +1,244 @@
 # XCUI Editor Agent Guide
+
+This file documents the current editor architecture for agents working under
+`editor/`. It describes the code that exists in this checkout, not a desired
+future shape.
+
+If this file conflicts with the current code, `editor/CMakeLists.txt`, or the
+real directory tree, trust the code and update this file in the same change.
+
 ## Build Shape
 
-The editor is a two-layer system.
+The important production targets are:
 
-- `XCUIEditorLib` is the reusable framework library.
-- `XCUIEditorApp` is the concrete editor application executable.
-- The build shape of `editor/` is `XCUIEditorLib <- XCUIEditorApp`.
-- `editor/src/**` and `editor/include/XCEditor/**` belong to the framework layer.
-- `editor/app/**` belongs to the app layer and is compiled directly into `XCUIEditorApp`.
-- App-internal windowing authority, planner, projection, and synchronization code now live in `editor/app/Windowing/System` and `editor/app/Windowing/Presentation`.
-- `app/Windowing` now owns app-side content controllers, coordinators, and frame transfer seams; `app/Platform/Win32` remains the concrete host.
-- Win32 hosting, utility windows, and editor-only rendering stay in `editor/app/**`.
-- `editor/include/XCEditor/**` exposes framework-level APIs only.
+- `XCUIEditorLib`: reusable XCEditor framework code from `editor/src` and
+  `editor/include/XCEditor`.
+- `XCUIEditorAppWindowing`: app-internal static library for the current
+  window authority, planner, store, presentation policy, host contracts,
+  content controllers, coordinators, frame transfer flow, and window manager.
+- `XCUIEditorApp`: concrete editor executable. Its output name is `XCEngine`.
 
-Architecture shorthand for this repo:
+Do not invent target boundaries that are not present in `editor/CMakeLists.txt`.
+Names such as `XCUIEditorAppCore`, `XCUIEditorAppLib`, and `XCUIEditorHost`
+are not current production library boundaries in this checkout.
 
-```text
-XCUIEditorLib
-  <- XCUIEditorApp
-```
+There is no public `editor/include/XCEditor/Windowing` layer yet. Windowing is
+currently an app-internal architecture under `editor/app/Windowing` plus the
+concrete Win32 host under `editor/app/Platform/Win32`.
 
-When describing the current architecture, treat `XCEditor/Windowing` as framework code and `app/Windowing` / `app/Platform/Win32` as the app-side orchestration and host layers.
+## Layering
 
-这份文档面向在 `editor/` 下工作的 coding agent / 开发者。它描述当前 editor 的真实工程边界、窗口架构和修改约束，不是产品说明。
+Use these ownership boundaries when changing code:
 
-如果本文和当前代码、`editor/CMakeLists.txt`、实际目录结构冲突，以当前 checkout 为准，并在本次工作里同步修正文档。
+- `editor/include/XCEditor` and `editor/src`: reusable editor framework.
+  Keep this layer independent from app state, Win32, D3D12 host code, and
+  `App::*` types.
+- `editor/app/Composition`, `Commands`, `Features`, `Project`, `Scene`,
+  `State`, `System`, `UtilityWindows`: editor product semantics.
+- `editor/app/Windowing/System`: authoritative window set, validation,
+  synchronization planning, and commit.
+- `editor/app/Windowing/Presentation`: projection policy derived from
+  authoritative state.
+- `editor/app/Windowing/Content`, `Coordinator`, `Frame`, `Host`: platform
+  neutral app window orchestration.
+- `editor/app/Platform/Win32`: native window, message dispatch, input,
+  lifecycle, chrome, and concrete host runtime.
+- `editor/app/Rendering`: editor rendering host and D3D12 integration.
 
-## 1. 当前定位
-
-`editor/` 是当前 editor 应用主线。
-
-当前工程事实：
-
-- 可复用 UI framework 的真实构建目标是 `XCUIEditorLib`。
-- editor 应用的真实可执行目标是 `XCUIEditorApp`。
-- `XCUIEditorApp` 的输出名是 `XCEngine`，产物为 `XCEngine.exe`。
-- `editor/src` + `editor/include/XCEditor` 是 XCEditor framework。
-- `editor/app` 是具体 XCEngine editor 应用层。
-- `editor/resources` 存放 editor 自有图标和 scene viewport shader。
-
-当前 `editor/CMakeLists.txt` 并没有把 app core、windowing seam、Win32 host、rendering host 拆成独立生产 target。除了 `XCUIEditorLib` 之外，其余 app / windowing / platform / rendering 代码仍直接编进 `XCUIEditorApp`。
-
-`XCUIEditorAppLib`、`XCUIEditorAppCore`、`XCUIEditorHost` 不是当前 `editor/CMakeLists.txt` 里真实定义的生产 target；它们只在部分测试脚本或清理逻辑里作为条件名称出现。不要把这些名字当成当前已经存在的模块边界。
-
-## 2. 当前分层
-
-推荐按下面五层理解和修改，但要记住这主要是目录和语义边界，不是已经被 CMake 强制落实的编译边界：
-
-1. `editor/src` / `editor/include/XCEditor`
-   XCEditor framework。这里应保持通用，不依赖具体 editor app、Win32 宿主或 D3D12 实现。
-
-2. `editor/app/Composition`、`Commands`、`Features`、`Project`、`Scene`、`State`、`Support`、`System`、`UtilityWindows`
-   editor 应用语义层。这里放 panel 组合、项目/场景运行时、选择状态、命令桥接、utility window 描述和 app 侧服务。
-
-3. `editor/app/Windowing`
-   平台无关的窗口主线。这里放 content controller contract、frame transfer request、workspace synchronization planner / presentation policy / authoritative window set。
-
-4. `editor/app/Platform/Win32`
-   Win32 host。这里负责 native window、消息分发、生命周期、输入翻译、窗口 chrome、host runtime 和 coordinator。
-
-5. `editor/app/Rendering`
-   editor 渲染宿主。这里负责 D3D12 UI 渲染、窗口 render loop、swapchain、viewport 资源和 scene viewport pass。
-
-依赖方向尽量保持为：
+The semantic dependency direction should remain:
 
 ```text
 XCEditor framework
-  <- app semantics
-  <- app/windowing
-  <- Platform/Win32
-  <- app/Rendering
+  <- editor app semantics
+  <- app windowing
+  <- Win32 host / rendering host
 ```
 
-现实约束：
+## Startup Flow
 
-- 当前只有 `XCUIEditorLib` 是真实独立 target。
-- 其余层级只是目录和 ownership 约定。
-- 修改时仍要主动控制 include 方向，避免把“语义上应该分层”写回成硬耦合。
-
-## 3. 顶层启动流程
-
-入口：
+The application starts through:
 
 ```text
 app/main.cpp
   -> RunXCUIEditorApp
   -> Application::Run
+  -> Application::Initialize
 ```
 
-当前启动主线：
-
-```text
-Application
-  -> EditorContext
-  -> Win32SystemInteractionHost
-  -> EditorWindowSystem
-  -> EditorWindowManager
-      -> EditorWindowHostRuntime
-      -> EditorWindowWorkspaceCoordinator
-      -> EditorUtilityWindowCoordinator
-      -> EditorWindowLifecycleCoordinator
-```
-
-primary workspace window 的 bootstrap 顺序是：
+The primary workspace window is initialized through:
 
 ```text
 EditorContext::BuildWorkspaceController()
   -> EditorWindowSystem::BootstrapPrimaryWindow(...)
   -> EditorWindowManager::CreateWorkspaceWindow(...)
+  -> EditorWindowContentFactory::CreateWorkspaceContentController(...)
+  -> EditorWindowHostRuntime::CreateHostWindow(...)
 ```
 
-不要把 primary window authority 初始化放回 Win32 host。当前 authoritative bootstrap 已经在 `EditorWindowSystem`。
+Keep authoritative window bootstrap in `EditorWindowSystem`; do not move it
+back into the Win32 host.
 
-## 4. 当前窗口系统事实
+## Window Authority Model
 
-### 4.1 Authority / Planner / Host Execution
+`EditorWindowSystem` owns the authoritative `UIEditorWindowWorkspaceSet` through
+`EditorWindowWorkspaceStore`.
 
-当前多窗口 workspace 主线里，几个核心对象的职责是：
-
-- `EditorWindowSystem`
-  - 持有 authoritative `UIEditorWindowWorkspaceSet`
-  - 通过 `EditorWindowWorkspaceStore` 做 validation / commit
-  - 构建 synchronization plan
-  - 处理显式 `workspaceMutation` request
-  - 处理 destroyed window reconciliation
-
-- `EditorWindowWorkspaceCoordinator`
-  - 采集 host snapshot
-  - 调用 `EditorWindowSystem` 生成 plan
-  - 执行 host-side create / update / close
-  - 处理 global tab drag、detach、cross-window dock/drop
-  - 处理 window presentation refresh
-  - 在 native destroy 时回到 `EditorWindowSystem` 做 reconcile
-
-重要事实：
-
-- `EditorWindowWorkspaceCoordinator` 已不再直接写 authority store。
-- 但它仍然很厚，仍同时承担 host 执行、presentation refresh、drag/detach 流程和部分回滚时序。
-- 当前不要把它描述成“纯粹的薄 host adapter”。
-
-### 4.2 Live Workspace Projection 还没有完全去状态化
-
-`EditorWorkspaceWindowContentController` 当前内部仍持有：
-
-- `UIEditorWorkspaceController`
-- `EditorShellRuntime`
-- `EditorWindowFrameOrchestrator`
-
-这意味着当前 workspace window 仍然有一个 live mutable controller。它已经不是 authority，但也还不是完全只读 projection。
-
-当前真实行为是：
-
-- `EditorWorkspaceWindowContentController::UpdateAndAppend(...)` 会在 layout snapshot 发生变化时发出显式 `workspaceMutation` request。
-- `EditorWorkspaceWindowContentController` 现在持有显式 `EditorWorkspaceWindowProjection`，host 常规同步 / presentation 路径优先消费 projection refresh，而不是整体替换 live controller。
-- `EditorWindow::TryGetWorkspaceController()` 仍保留给局部交互 / 过渡路径使用，但它不再是常规 host 同步主接口。
-- 每个 workspace window 依然持有自己的一份 live `UIEditorWorkspaceController`。
-
-因此：
-
-- 不要把当前架构写成“projection-only content controller 已完成”。
-
-## 5. 窗口类别与内容控制器
-
-当前窗口系统显式区分两类窗口：
-
-- `EditorWindowCategory::Workspace`
-- `EditorWindowCategory::Utility`
-
-两类窗口共享同一个 native host：
+Normal per-frame workspace edits now use direct writes into that authoritative
+state:
 
 ```text
-EditorWindow
-  -> EditorWindowRuntimeController
-  -> D3D12WindowRenderLoop
-  -> EditorWindowContentController
+EditorWorkspaceWindowContentController::UpdateAndAppend(...)
+  -> EditorWindowSystem::TryBuildLiveWindowWorkspaceController(windowId, ...)
+  -> UIEditorWorkspaceController::BindToState(...)
+  -> workspace operations mutate the bound authoritative workspace/session
 ```
 
-### 5.1 Workspace Window
-
-workspace window 的内容控制器是 `EditorWorkspaceWindowContentController`。
-
-它是完整 shell/workspace 容器，用于：
-
-- 主窗口
-- detached workspace window
-
-### 5.2 Utility Window
-
-utility window 的内容控制器是 `EditorUtilityWindowContentController`，内部承载 `EditorUtilityWindowPanel`。
-
-当前 registry / factory 主线是显式 descriptor 驱动：
-
-- `EditorUtilityWindowDescriptor`
-- `EditorUtilityWindowReusePolicy`
-- `EditorWindowChromePolicy`
-- `EditorWindowNativeStylePolicy`
-
-当前已注册的 utility window：
-
-- `ColorPicker`
-- `AddComponent`
-
-两者当前都使用 `SingleInstance` 复用策略。
-
-### 5.3 Capability 校验
-
-窗口内容能力由 `EditorWindowContentCapabilities` 描述，`EditorWindowHostRuntime::CreateEditorWindow(...)` 在创建时做硬校验：
-
-- `Workspace` 分类要求 `capabilities.workspace == true`
-- `Utility` 分类要求 `capabilities.utilityPanel == true`
-
-不要依赖“后续 coordinator 看到空 binding 再兜底”这种旧思路。
-
-## 6. Frame Request 与每帧主线
-
-`EditorWindowFrameTransferRequests` 当前按两个子域组织：
+The old normal path is obsolete:
 
 ```text
-workspace:
-  workspaceMutation
-  beginGlobalTabDrag
-  detachPanel
-
-utility:
-  openUtilityWindow
+snapshot diff
+  -> workspaceMutation frame request
+  -> coordinator
+  -> synchronization plan
+  -> commit
 ```
 
-当前事实：
+Do not reintroduce `workspaceMutation` as the steady-state route for ordinary
+layout, tab, visibility, or active-panel edits inside an existing workspace
+window.
 
-- `workspaceMutation` 已经是 frame 内 workspace 变化的显式回传入口。
-- `openUtilityWindow` 来自 `EditorContext::RequestOpenUtilityWindow(...)`，由 `EditorWindowFrameOrchestrator` 消费 request state 后写入 frame transfer request。
-- queued immediate frame 也按这两个子域分别合并。
-
-steady-state frame 主路径是：
+Cross-window create, update, close, and destroyed-window reconciliation still
+use the planner/coordinator flow:
 
 ```text
-Application::Run
-  -> EditorWindowManager::RenderAllWindows
-      -> EditorWindowHostRuntime::RenderAllWindows
-          -> EditorWindowFrameDriver::DriveFrame
-              -> EditorWindowRuntimeController::UpdateAndAppend
-                  -> EditorWindowContentController::UpdateAndAppend
-          -> EditorWindowWorkspaceCoordinator::RefreshWindowPresentation
-          -> EditorWindowWorkspaceCoordinator::HandleWindowFrameTransferRequests
-          -> EditorUtilityWindowCoordinator::HandleWindowFrameTransferRequests
+target UIEditorWindowWorkspaceSet
+  -> EditorWindowSystem::BuildPlanForWindowSet(...)
+  -> EditorWindowWorkspaceCoordinator::ApplySynchronizationPlan(...)
+  -> EditorWindowSystem::CommitSynchronizationPlan(...)
 ```
 
-另外，`WM_PAINT`、`WM_SIZE`、`WM_DPICHANGED`、`WM_EXITSIZEMOVE` 等消息也会触发 immediate frame，并在 message dispatcher 中 flush queued transfer requests。
+`EditorWindowWorkspaceCoordinator::RefreshWindowPresentation(...)` refreshes
+each workspace window projection from authoritative state. Presentation should
+follow authority; it should not become a second source of truth.
 
-## 7. 修改规范
+## Frame Transfer Requests
 
-- 先判断改动属于 framework、app semantics、windowing、Win32 host 还是 rendering host。
-- 小改动优先贴近现有模式，不顺手做跨层重构。
-- 新增通用 widget 放 `editor/src` / `editor/include/XCEditor`。
-- 新增具体 editor 功能放 `editor/app/Features/<FeatureName>`，再由 composition 装配。
-- 新增 utility window 先补 `EditorUtilityWindowKind`、`EditorUtilityWindowDescriptor`、`CreateEditorUtilityWindowPanel(...)`，不要直接在 Win32 coordinator 里硬编码窗口类型。
-- 新增跨窗口语义时，优先增加显式 frame request 或 app/windowing plan builder，不要回退到 Win32 host 直接读写 authority。
-- 修改窗口同步逻辑时，区分“当前代码事实”和“长期目标”。当前还存在 live mutable projection，不要按尚未落地的终态直接删接口。
-- 不要让 `editor/include/XCEditor/**` 暴露 `App::*` 类型。
-- draw append 只负责绘制，不顺手修改 scene / project / authority 状态。
+`EditorWindowFrameTransferRequests` is only for host-side or cross-window side
+effects that cannot be represented as direct in-window workspace edits.
 
-## 8. 当前架构债务
+Current request fields are:
 
-当前仍然存在的主要债务：
+- `workspace.beginGlobalTabDrag`
+- `workspace.detachPanel`
+- `utility.openUtilityWindow`
 
-- 除 `XCUIEditorLib` 外，app core、windowing、Win32 host、rendering host 还没有真实拆成独立 target。
-- `EditorContext` 仍然很重，混合了 shell asset、项目/场景运行时、selection、command focus、utility window request 和状态输出。
-- `EditorShellRuntime` 仍然很重，既负责 shell compose / interaction，也负责 hosted panel、viewport request 和 draw append。
-- `EditorWorkspaceWindowContentController` 仍持有 live mutable `UIEditorWorkspaceController`，只是 host 常规同步 / presentation 已经切到 projection refresh；projection 和 authority 的边界仍未完全硬化。
-- `EditorWindowWorkspaceCoordinator` 仍然过厚，还没有收缩成纯粹的 host executor + native event bridge。
-- `EditorWindow::TryGetWorkspaceController()` 仍存在于交互 / 过渡路径，说明 live projection 去状态化还没完成；但常规同步路径已经不再依赖 `ReplaceWorkspaceController()`。
+There is no `workspace.workspaceMutation` field in the current frame transfer
+contract. Treat any doc, comment, or test name that says otherwise as stale.
 
-这些都是当前事实，不要在新的规范文档或代码注释里把它们写成“已经解决”。
+## Window Categories
 
-## 9. 验证入口
+Workspace and utility windows share the native host path but use distinct
+content controllers.
 
-当前 editor 相关验证入口统一在 `tests/UI/Editor`：
+- Workspace windows use `EditorWorkspaceWindowContentController`.
+- Utility windows use `EditorUtilityWindowContentController`.
+- App windowing creates content through `EditorWindowContentFactory`.
+- The concrete host validates `EditorWindowContentCapabilities` when a native
+  host window is created.
 
-- `editor_ui_tests`
-  framework 和基础 UI 单元测试。
-- `editor_windowing_phase1_tests`
-  当前窗口 authority / planner / reconcile 规则的 focused unit tests。
-- `xcui_editor_app_smoke`
-  editor 启动烟测。
-- `tests/UI/Editor/manual_validation`
-  复杂交互人工验证场景。
+Utility windows are descriptor driven through `EditorUtilityWindowDescriptor`,
+`EditorUtilityWindowRegistry`, and `CreateEditorUtilityWindowPanel(...)`.
+Register new utility windows there rather than hard-coding them in Win32 host
+logic.
 
-条件事实：
+## Modification Rules
 
-- `editor_app_feature_tests` 只会在 `XCUIEditorAppLib` 等可选 target 真实存在时创建。
-- 不要把它当成当前 checkout 一定存在的测试目标。
+- First decide whether the change belongs to XCEditor framework, app semantics,
+  app windowing, Win32 host, or rendering host.
+- Keep public framework headers free of `App::*`, Win32, and D3D12 host types.
+- Use `editor/app/Windowing` for window semantics that are not inherently Win32.
+- Use `editor/app/Platform/Win32` only for native host behavior and message
+  integration.
+- Do not let `editor/app/Windowing` include `Platform/Win32` or D3D12 concrete
+  host headers.
+- Do not let Win32 host code create workspace or utility content directly.
+  It should receive content through the app-windowing host contract.
+- Use direct authoritative workspace binding for ordinary in-window workspace
+  mutations.
+- Use synchronization plans for operations that create, close, replace, or
+  reconcile workspace windows.
+- Use frame transfer requests only for host-side or cross-window effects.
+- Do not describe `XCEditor/Windowing` as an existing framework/public layer.
 
-涉及窗口系统的改动，优先保持：
+## Current Architecture Debt
 
-- `XCUIEditorApp` 可构建
-- `editor_windowing_phase1_tests` 不回退
-- `xcui_editor_app_smoke` 不回退
+The highest-value windowing boundary has been hardened: `XCUIEditorAppWindowing`
+now owns the app-internal window authority, presentation, content controller
+factory, coordinators, frame transfer flow, host contracts, and manager. The
+Win32 host is the concrete native adapter and creates native host windows from
+content supplied by app windowing.
 
-## 10. 推荐阅读入口
+The main remaining debt is promotion discipline. `XCUIEditorAppWindowing` is
+still app-internal and may depend on app semantics such as `EditorContext`,
+`EditorShellRuntime`, utility window descriptors, and product-specific content.
+Do not promote this surface to `XCEditor` until the authority model, host
+interfaces, frame transfer contract, and presentation projection are stable and
+generic enough to expose.
 
-开始 editor 相关任务时，优先阅读：
+Do not paper over this debt by documenting a public windowing framework that
+does not exist.
+
+## Validation
+
+Useful local targets for editor/windowing changes:
+
+- `cmake --build build --config Debug --target XCUIEditorApp`
+- `cmake --build build --config Debug --target editor_windowing_phase1_tests`
+- `cmake --build build --config Debug --target editor_ui_tests`
+
+Useful test executables when they are present in the configured build tree:
+
+- `build/tests/UI/Editor/unit/Debug/editor_windowing_phase1_tests.exe`
+- `build/tests/UI/Editor/unit/Debug/editor_ui_tests.exe`
+
+`xcui_editor_app_smoke` is a useful supplemental smoke test when the app target
+and smoke test are configured, but it is not the default windowing unit-test
+entry point. In the current Debug build, the direct 12-second smoke command is:
+
+```powershell
+build\tests\UI\Editor\smoke\Debug\editor_ui_smoke_runner.exe build\editor\Debug\XCEngine.exe
+```
+
+The runner sets `XCUIEDITOR_SMOKE_TEST_DURATION_SECONDS=12`, waits for the
+editor to launch, lets the app auto-exit, and treats a clean editor exit as
+success.
+
+## Recommended Reading
+
+Start with these files for editor/windowing work:
 
 - `editor/CMakeLists.txt`
 - `editor/app/Bootstrap/Application.*`
 - `editor/app/Composition/EditorContext.*`
 - `editor/app/Composition/EditorShellRuntime.*`
+- `editor/include/XCEditor/Workspace/UIEditorWorkspaceController.h`
+- `editor/src/Workspace/UIEditorWorkspaceController.cpp`
+- `editor/app/Windowing/System/EditorWindowSystem.*`
+- `editor/app/Windowing/System/EditorWindowWorkspaceStore.*`
+- `editor/app/Windowing/System/EditorWindowSynchronizationPlanner.*`
+- `editor/app/Windowing/Presentation/EditorWindowPresentationPolicy.*`
+- `editor/app/Windowing/Host/EditorWindowHostInterfaces.h`
 - `editor/app/Windowing/Content/EditorWindowContentController.h`
+- `editor/app/Windowing/Content/EditorWindowContentFactory.*`
 - `editor/app/Windowing/Content/EditorWorkspaceWindowContentController.*`
 - `editor/app/Windowing/Frame/EditorWindowFrameOrchestrator.*`
-- `editor/app/Windowing/System/EditorWindowSystem.h`
-- `editor/app/Windowing/System/EditorWindowSystem.cpp`
+- `editor/app/Windowing/Frame/EditorWindowTransferRequests.h`
+- `editor/app/Windowing/Coordinator/EditorWindowWorkspaceCoordinator.*`
+- `editor/app/Windowing/Coordinator/EditorUtilityWindowCoordinator.*`
+- `editor/app/Windowing/EditorWindowManager.*`
 - `editor/app/Platform/Win32/Windowing/EditorWindow.*`
 - `editor/app/Platform/Win32/Windowing/EditorWindowHostRuntime.*`
-- `editor/app/Platform/Win32/Windowing/EditorWindowWorkspaceCoordinator.*`
-- `editor/app/Platform/Win32/Windowing/EditorUtilityWindowCoordinator.*`
-- `editor/app/UtilityWindows/EditorUtilityWindowRegistry.*`
+- `editor/app/Platform/Win32/Windowing/EditorWindowMessageDispatcher.*`
+- `tests/UI/Editor/unit/test_editor_window_synchronization_planner.cpp`
 - `tests/UI/Editor/unit/CMakeLists.txt`
 - `tests/UI/Editor/smoke/CMakeLists.txt`
diff --git a/editor/CMakeLists.txt b/editor/CMakeLists.txt
index cbea546b..0c39ee80 100644
--- a/editor/CMakeLists.txt
+++ b/editor/CMakeLists.txt
@@ -170,6 +170,15 @@ target_link_libraries(XCUIEditorLib PUBLIC
 xcui_editor_apply_common_target_settings(XCUIEditorLib PUBLIC)
 
 set(XCUI_EDITOR_APP_WINDOWING_SOURCES
+    app/Windowing/EditorWindowManager.cpp
+    app/Windowing/Coordinator/EditorWindowLifecycleCoordinator.cpp
+    app/Windowing/Coordinator/EditorUtilityWindowCoordinator.cpp
+    app/Windowing/Coordinator/EditorWindowWorkspaceCoordinator.cpp
+    app/Windowing/Content/EditorWindowContentController.cpp
+    app/Windowing/Content/EditorWindowContentFactory.cpp
+    app/Windowing/Content/EditorUtilityWindowContentController.cpp
+    app/Windowing/Content/EditorWorkspaceWindowContentController.cpp
+    app/Windowing/Frame/EditorWindowFrameOrchestrator.cpp
     app/Windowing/Presentation/EditorWindowPresentationPolicy.cpp
     app/Windowing/System/EditorWindowSynchronizationPlanner.cpp
     app/Windowing/System/EditorWindowSystem.cpp
@@ -279,17 +288,6 @@ if(XCENGINE_BUILD_XCUI_EDITOR_APP)
         app/Scene/EditorSceneBridge.cpp
     )
 
-    set(XCUI_EDITOR_APP_WINDOWING_SOURCES
-        app/Windowing/EditorWindowManager.cpp
-        app/Windowing/Coordinator/EditorWindowLifecycleCoordinator.cpp
-        app/Windowing/Coordinator/EditorUtilityWindowCoordinator.cpp
-        app/Windowing/Coordinator/EditorWindowWorkspaceCoordinator.cpp
-        app/Windowing/Content/EditorWindowContentFactory.cpp
-        app/Windowing/Content/EditorUtilityWindowContentController.cpp
-        app/Windowing/Content/EditorWorkspaceWindowContentController.cpp
-        app/Windowing/Frame/EditorWindowFrameOrchestrator.cpp
-    )
-
     set(XCUI_EDITOR_APP_PLATFORM_SOURCES
         app/Platform/Win32/Windowing/EditorWindow.cpp
         app/Platform/Win32/Windowing/EditorFloatingWindowPlacement.cpp
@@ -317,7 +315,6 @@ if(XCENGINE_BUILD_XCUI_EDITOR_APP)
         ${XCUI_EDITOR_HOST_PLATFORM_SOURCES}
         ${XCUI_EDITOR_HOST_RENDERING_SOURCES}
         ${XCUI_EDITOR_APP_CORE_SOURCES}
-        ${XCUI_EDITOR_APP_WINDOWING_SOURCES}
         ${XCUI_EDITOR_APP_PLATFORM_SOURCES}
     )
 
diff --git a/editor/app/Bootstrap/Application.cpp b/editor/app/Bootstrap/Application.cpp
index 7e9b038d..fdac0a83 100644
--- a/editor/app/Bootstrap/Application.cpp
+++ b/editor/app/Bootstrap/Application.cpp
@@ -2,7 +2,6 @@
 #include "Bootstrap/EditorResources.h"
 #include "System/SystemInteractionService.h"
 #include "Composition/EditorContext.h"
-#include "Windowing/Content/EditorWindowContentFactory.h"
 #include "Windowing/EditorWindowManager.h"
 #include "Platform/Win32/System/Win32SystemInteractionHost.h"
 #include "Platform/Win32/Windowing/EditorWindow.h"
@@ -141,13 +140,10 @@ bool Application::Initialize(HINSTANCE hInstance, int nCmdShow) {
     hostConfig.windowStyle = kBorderlessWindowStyle;
     hostConfig.primaryWindowTitle = kWindowTitle;
     hostConfig.windowUserData = this;
-    m_windowContentFactory =
-        App::CreateDefaultEditorWindowContentFactory(*m_windowSystem);
     m_windowHostRuntime = std::make_unique<App::EditorWindowHostRuntime>(
         hostConfig,
         m_repoRoot,
-        *m_editorContext,
-        *m_windowContentFactory);
+        m_editorContext->GetShellAsset().captureRootPath);
     m_windowManager = std::make_unique<App::EditorWindowManager>(
         *m_editorContext,
         *m_windowSystem,
@@ -228,7 +224,6 @@ void Application::Shutdown() {
         m_windowManager.reset();
     }
     m_windowHostRuntime.reset();
-    m_windowContentFactory.reset();
     m_windowSystem.reset();
 
     if (m_editorContext != nullptr) {
diff --git a/editor/app/Bootstrap/Application.h b/editor/app/Bootstrap/Application.h
index 6443c379..2be7b2e2 100644
--- a/editor/app/Bootstrap/Application.h
+++ b/editor/app/Bootstrap/Application.h
@@ -15,7 +15,6 @@ class EditorWindowSystem;
 
 namespace App {
 class EditorContext;
-class EditorWindowContentFactory;
 class EditorWindowManager;
 class EditorWindowHostRuntime;
 }
@@ -55,7 +54,6 @@ private:
     std::chrono::milliseconds m_smokeTestDuration = std::chrono::milliseconds::zero();
     std::unique_ptr<App::EditorContext> m_editorContext = {};
     std::unique_ptr<EditorWindowSystem> m_windowSystem = {};
-    std::unique_ptr<App::EditorWindowContentFactory> m_windowContentFactory = {};
     std::unique_ptr<App::EditorWindowHostRuntime> m_windowHostRuntime = {};
     std::unique_ptr<App::EditorWindowManager> m_windowManager = {};
     std::unique_ptr<System::SystemInteractionService> m_systemInteractionHost = {};
diff --git a/editor/app/Platform/Win32/Runtime/EditorWindowRuntimeController.cpp b/editor/app/Platform/Win32/Runtime/EditorWindowRuntimeController.cpp
index 3125182c..fba2e142 100644
--- a/editor/app/Platform/Win32/Runtime/EditorWindowRuntimeController.cpp
+++ b/editor/app/Platform/Win32/Runtime/EditorWindowRuntimeController.cpp
@@ -1,7 +1,6 @@
 #include "Platform/Win32/Runtime/EditorWindowRuntimeController.h"
 
 #include "Bootstrap/EditorResources.h"
-#include "Composition/EditorContext.h"
 #include "Platform/Win32/Windowing/EditorWindowSupport.h"
 #include "Support/EmbeddedPngLoader.h"
 
@@ -157,8 +156,8 @@ bool EditorWindowRuntimeController::Initialize(
         LogRuntimeTrace("app", attachResult.warning);
     }
 
-    editorContext.AttachTextMeasurer(m_textSystem);
     assert(m_contentController != nullptr);
+    m_contentController->PrepareEditorContext(editorContext, m_textSystem);
     m_contentController->Initialize(EditorWindowContentInitializationContext{
         .repoRoot = repoRoot,
         .editorContext = editorContext,
@@ -193,7 +192,7 @@ bool EditorWindowRuntimeController::Initialize(
     m_screenshotController.Initialize(captureRoot);
     if (autoCaptureOnStartup) {
         m_screenshotController.RequestCapture("startup");
-        editorContext.SetStatus("Capture", "Startup capture requested.");
+        m_contentController->NotifyStartupCaptureRequested(editorContext);
     }
 
     return true;
@@ -254,6 +253,26 @@ bool EditorWindowRuntimeController::ApplyResize(UINT width, UINT height) {
     return resizeResult.hasViewportSurfacePresentation;
 }
 
+void EditorWindowRuntimeController::PrepareEditorContext(EditorContext& editorContext) {
+    if (m_contentController != nullptr) {
+        m_contentController->PrepareEditorContext(editorContext, m_textSystem);
+    }
+}
+
+bool EditorWindowRuntimeController::IsEditorContextValid(
+    const EditorContext& editorContext) const {
+    return m_contentController != nullptr &&
+        m_contentController->IsEditorContextValid(editorContext);
+}
+
+void EditorWindowRuntimeController::AppendInvalidFrame(
+    const EditorContext& editorContext,
+    ::XCEngine::UI::UIDrawList& drawList) const {
+    if (m_contentController != nullptr) {
+        m_contentController->AppendInvalidFrame(editorContext, drawList);
+    }
+}
+
 Host::D3D12WindowRenderLoopFrameContext EditorWindowRuntimeController::BeginFrame() {
     UpdateFrameTiming();
     return m_windowRenderLoop.BeginFrame();
diff --git a/editor/app/Platform/Win32/Runtime/EditorWindowRuntimeController.h b/editor/app/Platform/Win32/Runtime/EditorWindowRuntimeController.h
index fc684206..2ef0afa1 100644
--- a/editor/app/Platform/Win32/Runtime/EditorWindowRuntimeController.h
+++ b/editor/app/Platform/Win32/Runtime/EditorWindowRuntimeController.h
@@ -22,6 +22,12 @@
 #include <memory>
 #include <string>
 
+namespace XCEngine::UI {
+
+class UIDrawList;
+
+} // namespace XCEngine::UI
+
 namespace XCEngine::UI::Editor::App {
 
 class EditorContext;
@@ -65,6 +71,11 @@ public:
     void ResetInteractionState();
     bool ApplyResize(UINT width, UINT height);
 
+    void PrepareEditorContext(EditorContext& editorContext);
+    bool IsEditorContextValid(const EditorContext& editorContext) const;
+    void AppendInvalidFrame(
+        const EditorContext& editorContext,
+        ::XCEngine::UI::UIDrawList& drawList) const;
     Host::D3D12WindowRenderLoopFrameContext BeginFrame();
     Host::D3D12WindowRenderLoopPresentResult Present(
         const ::XCEngine::UI::UIDrawData& drawData);
diff --git a/editor/app/Platform/Win32/Windowing/EditorWindow.cpp b/editor/app/Platform/Win32/Windowing/EditorWindow.cpp
index 7666259d..d22e79e5 100644
--- a/editor/app/Platform/Win32/Windowing/EditorWindow.cpp
+++ b/editor/app/Platform/Win32/Windowing/EditorWindow.cpp
@@ -5,10 +5,8 @@
 #include "Platform/Win32/Runtime/EditorWindowFrameDriver.h"
 #include "Platform/Win32/Windowing/EditorWindowSession.h"
 #include "Platform/Win32/Windowing/EditorWindowSupport.h"
-#include "Windowing/Frame/EditorWindowFrameOrchestrator.h"
 #include "Platform/Win32/Runtime/EditorWindowInputController.h"
 #include "Platform/Win32/Runtime/EditorWindowRuntimeController.h"
-#include "Composition/EditorContext.h"
 #include <XCEditor/Docking/UIEditorDockHostTransfer.h>
 #include <XCEditor/Foundation/UIEditorRuntimeTrace.h>
 #include <XCEditor/Shell/UIEditorShellInteraction.h>
@@ -98,7 +96,6 @@ EditorWindow::EditorWindow(
           chromePolicy,
           primary))
     , m_chromeController(std::make_unique<EditorWindowChromeController>())
-    , m_frameOrchestrator(std::make_unique<EditorWindowFrameOrchestrator>())
     , m_inputController(std::make_unique<EditorWindowInputController>())
     , m_runtime(std::make_unique<EditorWindowRuntimeController>(
           std::move(contentController))) {}
@@ -641,12 +638,12 @@ EditorWindowFrameTransferRequests EditorWindow::RenderFrame(
         kShellSurfaceColor);
 
     EditorWindowFrameTransferRequests transferRequests = {};
-    if (editorContext.IsValid()) {
+    if (m_runtime->IsEditorContextValid(editorContext)) {
         transferRequests =
             RenderRuntimeFrame(editorContext, globalTabDragActive, workspaceBounds, drawData);
     } else {
         UIDrawList& invalidDrawList = drawData.EmplaceDrawList("XCEditorWindow.Invalid");
-        m_frameOrchestrator->AppendInvalidFrame(editorContext, invalidDrawList);
+        m_runtime->AppendInvalidFrame(editorContext, invalidDrawList);
     }
 
     UIDrawList& windowChromeDrawList = drawData.EmplaceDrawList("XCEditorWindow.Chrome");
@@ -721,7 +718,7 @@ EditorWindowFrameTransferRequests EditorWindow::RenderRuntimeFrame(
     std::vector<UIInputEvent> frameEvents = m_inputController->TakePendingEvents();
     const bool useDetachedTitleBarTabStrip =
         m_chromeController->ShouldUseDetachedTitleBarTabStrip(*this);
-    editorContext.AttachTextMeasurer(m_runtime->GetTextMeasurer());
+    m_runtime->PrepareEditorContext(editorContext);
     const Host::D3D12WindowRenderLoopFrameContext frameContext = m_runtime->BeginFrame();
     if (!frameContext.warning.empty()) {
         LogRuntimeTrace("viewport", frameContext.warning);
diff --git a/editor/app/Platform/Win32/Windowing/EditorWindow.h b/editor/app/Platform/Win32/Windowing/EditorWindow.h
index 55242ad9..2b04e6f1 100644
--- a/editor/app/Platform/Win32/Windowing/EditorWindow.h
+++ b/editor/app/Platform/Win32/Windowing/EditorWindow.h
@@ -54,7 +54,6 @@ class EditorWindowContentController;
 class EditorWindowChromeController;
 class EditorWindowDockHostBinding;
 class EditorWindowFrameDriver;
-class EditorWindowFrameOrchestrator;
 class EditorWindowHostRuntime;
 class EditorWindowInputController;
 class EditorWindowLifecycleCoordinator;
@@ -201,7 +200,6 @@ private:
 
     std::unique_ptr<EditorWindowSession> m_session = {};
     std::unique_ptr<EditorWindowChromeController> m_chromeController = {};
-    std::unique_ptr<EditorWindowFrameOrchestrator> m_frameOrchestrator = {};
     std::unique_ptr<EditorWindowInputController> m_inputController = {};
     std::unique_ptr<EditorWindowRuntimeController> m_runtime = {};
 };
diff --git a/editor/app/Platform/Win32/Windowing/EditorWindowHostRuntime.cpp b/editor/app/Platform/Win32/Windowing/EditorWindowHostRuntime.cpp
index 96eb9124..35453b18 100644
--- a/editor/app/Platform/Win32/Windowing/EditorWindowHostRuntime.cpp
+++ b/editor/app/Platform/Win32/Windowing/EditorWindowHostRuntime.cpp
@@ -1,11 +1,9 @@
 #include "Platform/Win32/Windowing/EditorWindowHostRuntime.h"
 
 #include "Bootstrap/EditorResources.h"
-#include "Composition/EditorContext.h"
 #include "Platform/Win32/Chrome/EditorWindowChromeController.h"
 #include "Platform/Win32/Windowing/EditorFloatingWindowPlacement.h"
 #include "Platform/Win32/Windowing/EditorWindow.h"
-#include "Windowing/Content/EditorWindowContentFactory.h"
 #include "Windowing/Content/EditorWindowContentController.h"
 #include "Windowing/Host/EditorWindowHostCoordinator.h"
 #include "Platform/Win32/Runtime/EditorWindowFrameDriver.h"
@@ -57,16 +55,14 @@ std::string DescribeHostWindows(
 EditorWindowHostRuntime::EditorWindowHostRuntime(
     EditorWindowHostConfig hostConfig,
     std::filesystem::path repoRoot,
-    EditorContext& editorContext,
-    EditorWindowContentFactory& contentFactory)
+    std::filesystem::path captureRoot)
     : m_hostConfig(hostConfig),
       m_repoRoot(std::move(repoRoot)),
-      m_editorContext(editorContext),
-      m_contentFactory(contentFactory) {}
+      m_captureRoot(std::move(captureRoot)) {}
 
 EditorWindowHostRuntime::~EditorWindowHostRuntime() = default;
 
-EditorWindow* EditorWindowHostRuntime::CreateEditorWindow(
+EditorWindow* EditorWindowHostRuntime::CreateHostWindow(
     std::unique_ptr<EditorWindowContentController> contentController,
     const EditorWindowCreateParams& params) {
     if (contentController == nullptr) {
@@ -177,10 +173,14 @@ EditorWindow* EditorWindowHostRuntime::CreateEditorWindow(
         SendMessageW(hwnd, WM_SETICON, ICON_SMALL, reinterpret_cast<LPARAM>(smallIcon));
     }
 
+    if (m_hostCoordinator == nullptr) {
+        return failWindowInitialization("managed window initialization failed: coordinator missing");
+    }
+
     if (!rawWindow->Initialize(
             m_repoRoot,
-            m_editorContext,
-            m_editorContext.GetShellAsset().captureRootPath,
+            m_hostCoordinator->GetEditorContext(),
+            m_captureRoot,
             params.autoCaptureOnStartup)) {
         return failWindowInitialization("managed window initialization failed");
     }
@@ -190,35 +190,6 @@ EditorWindow* EditorWindowHostRuntime::CreateEditorWindow(
     return rawWindow;
 }
 
-EditorWindow* EditorWindowHostRuntime::CreateWorkspaceWindow(
-    const UIEditorWindowWorkspaceState& windowState,
-    const EditorWindowCreateParams& params) {
-    if (windowState.windowId.empty()) {
-        LogRuntimeTrace("window", "workspace window creation rejected: state missing window id");
-        return nullptr;
-    }
-    if (!params.windowId.empty() && windowState.windowId != params.windowId) {
-        LogRuntimeTrace(
-            "window",
-            "workspace window creation rejected: state window id '" +
-                windowState.windowId + "' does not match create params '" +
-                params.windowId + "'");
-        return nullptr;
-    }
-
-    return CreateEditorWindow(
-        m_contentFactory.CreateWorkspaceContentController(windowState),
-        params);
-}
-
-EditorWindow* EditorWindowHostRuntime::CreateUtilityWindow(
-    const EditorUtilityWindowDescriptor& descriptor,
-    const EditorWindowCreateParams& params) {
-    return CreateEditorWindow(
-        m_contentFactory.CreateUtilityContentController(descriptor),
-        params);
-}
-
 void EditorWindowHostRuntime::BindHostCoordinator(
     EditorWindowHostCoordinator& hostCoordinator) {
     m_hostCoordinator = &hostCoordinator;
@@ -370,7 +341,7 @@ void EditorWindowHostRuntime::RenderAllWindows() {
         EditorWindowFrameTransferRequests transferRequests =
             EditorWindowFrameDriver::DriveFrame(
                 *window,
-                m_editorContext,
+                m_hostCoordinator->GetEditorContext(),
                 m_hostCoordinator->IsGlobalTabDragActive());
         m_hostCoordinator->RefreshWindowPresentation(*window);
         if (!transferRequests.HasPendingRequests()) {
diff --git a/editor/app/Platform/Win32/Windowing/EditorWindowHostRuntime.h b/editor/app/Platform/Win32/Windowing/EditorWindowHostRuntime.h
index 03875d48..fc259d0d 100644
--- a/editor/app/Platform/Win32/Windowing/EditorWindowHostRuntime.h
+++ b/editor/app/Platform/Win32/Windowing/EditorWindowHostRuntime.h
@@ -12,29 +12,19 @@
 
 namespace XCEngine::UI::Editor::App {
 
-class EditorContext;
 class EditorWindow;
 class EditorWindowContentController;
-class EditorWindowContentFactory;
-struct EditorUtilityWindowDescriptor;
 
 class EditorWindowHostRuntime final : public EditorWindowHostRuntimeServices {
 public:
     EditorWindowHostRuntime(
         EditorWindowHostConfig hostConfig,
         std::filesystem::path repoRoot,
-        EditorContext& editorContext,
-        EditorWindowContentFactory& contentFactory);
+        std::filesystem::path captureRoot);
     ~EditorWindowHostRuntime();
 
-    EditorWindow* CreateEditorWindow(
+    EditorWindow* CreateHostWindow(
         std::unique_ptr<EditorWindowContentController> contentController,
-        const EditorWindowCreateParams& params);
-    EditorWindow* CreateWorkspaceWindow(
-        const UIEditorWindowWorkspaceState& windowState,
-        const EditorWindowCreateParams& params) override;
-    EditorWindow* CreateUtilityWindow(
-        const EditorUtilityWindowDescriptor& descriptor,
         const EditorWindowCreateParams& params) override;
     void BindHostCoordinator(EditorWindowHostCoordinator& hostCoordinator) override;
     void HandlePendingNativeWindowCreated(HWND hwnd);
@@ -87,8 +77,7 @@ private:
 
     EditorWindowHostConfig m_hostConfig = {};
     std::filesystem::path m_repoRoot = {};
-    EditorContext& m_editorContext;
-    EditorWindowContentFactory& m_contentFactory;
+    std::filesystem::path m_captureRoot = {};
     std::vector<std::unique_ptr<EditorWindow>> m_windows = {};
     EditorWindow* m_pendingCreateWindow = nullptr;
     EditorWindowHostCoordinator* m_hostCoordinator = nullptr;
diff --git a/editor/app/Platform/Win32/Windowing/EditorWindowSession.cpp b/editor/app/Platform/Win32/Windowing/EditorWindowSession.cpp
index 812e04f4..58d8f8a0 100644
--- a/editor/app/Platform/Win32/Windowing/EditorWindowSession.cpp
+++ b/editor/app/Platform/Win32/Windowing/EditorWindowSession.cpp
@@ -112,10 +112,6 @@ void EditorWindowSession::SetTitle(std::wstring title) {
 void EditorWindowSession::QueueCompletedImmediateFrame(
     EditorWindowFrameTransferRequests transferRequests) {
     m_hasQueuedCompletedImmediateFrame = true;
-    if (transferRequests.workspace.workspaceMutation.has_value()) {
-        m_queuedImmediateFrameTransferRequests.workspace.workspaceMutation =
-            std::move(transferRequests.workspace.workspaceMutation);
-    }
     if (transferRequests.workspace.beginGlobalTabDrag.has_value()) {
         m_queuedImmediateFrameTransferRequests.workspace.beginGlobalTabDrag =
             std::move(transferRequests.workspace.beginGlobalTabDrag);
diff --git a/editor/app/Windowing/Content/EditorWindowContentController.cpp b/editor/app/Windowing/Content/EditorWindowContentController.cpp
new file mode 100644
index 00000000..1314c247
--- /dev/null
+++ b/editor/app/Windowing/Content/EditorWindowContentController.cpp
@@ -0,0 +1,41 @@
+#include "Windowing/Content/EditorWindowContentController.h"
+
+#include "Composition/EditorContext.h"
+#include "Windowing/EditorWindowShared.h"
+
+#include <XCEngine/UI/DrawData.h>
+
+namespace XCEngine::UI::Editor::App {
+
+void EditorWindowContentController::PrepareEditorContext(
+    EditorContext& context,
+    UIEditorTextMeasurer& textMeasurer) {
+    context.AttachTextMeasurer(textMeasurer);
+}
+
+bool EditorWindowContentController::IsEditorContextValid(const EditorContext& context) const {
+    return context.IsValid();
+}
+
+void EditorWindowContentController::AppendInvalidFrame(
+    const EditorContext& context,
+    ::XCEngine::UI::UIDrawList& drawList) const {
+    drawList.AddText(
+        ::XCEngine::UI::UIPoint(28.0f, 28.0f),
+        "Editor shell asset invalid.",
+        kShellTextColor,
+        16.0f);
+    drawList.AddText(
+        ::XCEngine::UI::UIPoint(28.0f, 54.0f),
+        context.GetValidationMessage().empty()
+            ? std::string("Unknown validation error.")
+            : context.GetValidationMessage(),
+        kShellMutedTextColor,
+        12.0f);
+}
+
+void EditorWindowContentController::NotifyStartupCaptureRequested(EditorContext& context) {
+    context.SetStatus("Capture", "Startup capture requested.");
+}
+
+} // namespace XCEngine::UI::Editor::App
diff --git a/editor/app/Windowing/Content/EditorWindowContentController.h b/editor/app/Windowing/Content/EditorWindowContentController.h
index 7b0ea12c..b4e358fd 100644
--- a/editor/app/Windowing/Content/EditorWindowContentController.h
+++ b/editor/app/Windowing/Content/EditorWindowContentController.h
@@ -22,6 +22,7 @@ class RenderContext;
 namespace XCEngine::UI {
 
 class UIDrawData;
+class UIDrawList;
 
 struct UIInputEvent;
 struct UIPoint;
@@ -158,6 +159,12 @@ public:
     }
 
     virtual void Initialize(const EditorWindowContentInitializationContext&) {}
+    virtual void PrepareEditorContext(EditorContext& context, UIEditorTextMeasurer& textMeasurer);
+    virtual bool IsEditorContextValid(const EditorContext& context) const;
+    virtual void AppendInvalidFrame(
+        const EditorContext& context,
+        ::XCEngine::UI::UIDrawList& drawList) const;
+    virtual void NotifyStartupCaptureRequested(EditorContext& context);
     virtual void Shutdown() {}
     virtual void ResetInteractionState() {}
     virtual void SetViewportSurfacePresentationEnabled(bool) {}
diff --git a/editor/app/Windowing/Content/EditorWorkspaceWindowContentController.cpp b/editor/app/Windowing/Content/EditorWorkspaceWindowContentController.cpp
index ba458c9e..0e882663 100644
--- a/editor/app/Windowing/Content/EditorWorkspaceWindowContentController.cpp
+++ b/editor/app/Windowing/Content/EditorWorkspaceWindowContentController.cpp
@@ -4,31 +4,11 @@
 #include "Windowing/Presentation/EditorWindowPresentationPolicy.h"
 #include "Windowing/System/EditorWindowSystem.h"
 #include <XCEditor/Workspace/UIEditorDetachedWindowPolicy.h>
-#include <XCEditor/Workspace/UIEditorWorkspaceLayoutPersistence.h>
 
 namespace XCEngine::UI::Editor::App {
 
 namespace {
 
-UIEditorWorkspaceController BuildWorkspaceControllerForWindowState(
-    const UIEditorPanelRegistry& panelRegistry,
-    const UIEditorWindowWorkspaceState& windowState) {
-    return UIEditorWorkspaceController(
-        panelRegistry,
-        windowState.workspace,
-        windowState.session);
-}
-
-UIEditorWindowWorkspaceState BuildWindowStateFromController(
-    std::string_view windowId,
-    const UIEditorWorkspaceController& workspaceController) {
-    UIEditorWindowWorkspaceState windowState = {};
-    windowState.windowId = std::string(windowId);
-    windowState.workspace = workspaceController.GetWorkspace();
-    windowState.session = workspaceController.GetSession();
-    return windowState;
-}
-
 EditorWindowContentCursorKind ToContentCursorKind(ProjectPanel::CursorKind cursorKind) {
     switch (cursorKind) {
     case ProjectPanel::CursorKind::ResizeEW:
@@ -118,17 +98,10 @@ void EditorWorkspaceWindowContentController::RefreshWorkspaceProjection(
 }
 
 bool EditorWorkspaceWindowContentController::TryBuildAuthoritativeWorkspaceController(
-    UIEditorWorkspaceController& outController) const {
-    const UIEditorWindowWorkspaceState* windowState =
-        m_windowSystem.FindWindowState(m_windowId);
-    if (windowState == nullptr) {
-        return false;
-    }
-
-    outController = BuildWorkspaceControllerForWindowState(
-        m_windowSystem.GetPanelRegistry(),
-        *windowState);
-    return true;
+    UIEditorWorkspaceController& outController) {
+    return m_windowSystem.TryBuildLiveWindowWorkspaceController(
+        m_windowId,
+        outController);
 }
 
 void EditorWorkspaceWindowContentController::Initialize(
@@ -161,10 +134,7 @@ EditorWindowFrameTransferRequests EditorWorkspaceWindowContentController::Update
         return {};
     }
 
-    const auto beforeSnapshot = BuildUIEditorWorkspaceLayoutSnapshot(
-        workspaceController.GetWorkspace(),
-        workspaceController.GetSession());
-    EditorWindowFrameTransferRequests transferRequests = m_frameOrchestrator.UpdateAndAppend(
+    return m_frameOrchestrator.UpdateAndAppend(
         context.editorContext,
         workspaceController,
         m_shellRuntime,
@@ -176,15 +146,6 @@ EditorWindowFrameTransferRequests EditorWorkspaceWindowContentController::Update
         context.globalTabDragActive,
         context.useDetachedTitleBarTabStrip,
         drawData);
-    const auto afterSnapshot = BuildUIEditorWorkspaceLayoutSnapshot(
-        workspaceController.GetWorkspace(),
-        workspaceController.GetSession());
-    if (!AreUIEditorWorkspaceLayoutSnapshotsEquivalent(beforeSnapshot, afterSnapshot)) {
-        transferRequests.workspace.workspaceMutation = EditorWindowWorkspaceMutationRequest{
-            .windowState = BuildWindowStateFromController(m_windowId, workspaceController),
-        };
-    }
-    return transferRequests;
 }
 
 void EditorWorkspaceWindowContentController::RenderRequestedViewports(
diff --git a/editor/app/Windowing/Content/EditorWorkspaceWindowContentController.h b/editor/app/Windowing/Content/EditorWorkspaceWindowContentController.h
index 79be8a79..b89a1b5f 100644
--- a/editor/app/Windowing/Content/EditorWorkspaceWindowContentController.h
+++ b/editor/app/Windowing/Content/EditorWorkspaceWindowContentController.h
@@ -76,7 +76,7 @@ public:
         std::string_view fallbackWindowTitle) const override;
 
 private:
-    bool TryBuildAuthoritativeWorkspaceController(UIEditorWorkspaceController& outController) const;
+    bool TryBuildAuthoritativeWorkspaceController(UIEditorWorkspaceController& outController);
 
     std::string m_windowId = {};
     EditorWindowSystem& m_windowSystem;
diff --git a/editor/app/Windowing/Coordinator/EditorUtilityWindowCoordinator.cpp b/editor/app/Windowing/Coordinator/EditorUtilityWindowCoordinator.cpp
index dc2766f0..d194f15e 100644
--- a/editor/app/Windowing/Coordinator/EditorUtilityWindowCoordinator.cpp
+++ b/editor/app/Windowing/Coordinator/EditorUtilityWindowCoordinator.cpp
@@ -1,6 +1,8 @@
 #include "Windowing/Coordinator/EditorUtilityWindowCoordinator.h"
 
 #include "UtilityWindows/EditorUtilityWindowRegistry.h"
+#include "Windowing/Content/EditorWindowContentController.h"
+#include "Windowing/Content/EditorWindowContentFactory.h"
 #include "Windowing/Coordinator/EditorWindowLifecycleCoordinator.h"
 
 #include <cmath>
@@ -24,8 +26,10 @@ int ResolveOuterDimension(float value, int fallback) {
 }
 
 EditorUtilityWindowCoordinator::EditorUtilityWindowCoordinator(
-    EditorWindowHost& hostRuntime)
-    : m_hostRuntime(hostRuntime) {}
+    EditorWindowHost& hostRuntime,
+    EditorWindowContentFactory& contentFactory)
+    : m_hostRuntime(hostRuntime),
+      m_contentFactory(contentFactory) {}
 
 EditorUtilityWindowCoordinator::~EditorUtilityWindowCoordinator() = default;
 
@@ -117,8 +121,9 @@ bool EditorUtilityWindowCoordinator::TryProcessOpenUtilityWindowRequest(
         createParams.initialHeight = rect.Height();
     }
 
-    EditorHostWindow* utilityWindow =
-        m_hostRuntime.CreateUtilityWindow(*descriptor, createParams);
+    EditorHostWindow* utilityWindow = m_hostRuntime.CreateHostWindow(
+        m_contentFactory.CreateUtilityContentController(*descriptor),
+        createParams);
     if (utilityWindow == nullptr) {
         LogRuntimeTrace("utility", "failed to create utility window");
         return false;
diff --git a/editor/app/Windowing/Coordinator/EditorUtilityWindowCoordinator.h b/editor/app/Windowing/Coordinator/EditorUtilityWindowCoordinator.h
index 619c9f43..5de58a27 100644
--- a/editor/app/Windowing/Coordinator/EditorUtilityWindowCoordinator.h
+++ b/editor/app/Windowing/Coordinator/EditorUtilityWindowCoordinator.h
@@ -7,11 +7,14 @@
 
 namespace XCEngine::UI::Editor::App {
 
+class EditorWindowContentFactory;
 class EditorWindowLifecycleCoordinator;
 
 class EditorUtilityWindowCoordinator final {
 public:
-    explicit EditorUtilityWindowCoordinator(EditorWindowHost& hostRuntime);
+    EditorUtilityWindowCoordinator(
+        EditorWindowHost& hostRuntime,
+        EditorWindowContentFactory& contentFactory);
     ~EditorUtilityWindowCoordinator();
 
     void BindLifecycleCoordinator(EditorWindowLifecycleCoordinator& lifecycleCoordinator);
@@ -26,6 +29,7 @@ private:
     void LogRuntimeTrace(std::string_view channel, std::string_view message) const;
 
     EditorWindowHost& m_hostRuntime;
+    EditorWindowContentFactory& m_contentFactory;
     EditorWindowLifecycleCoordinator* m_lifecycleCoordinator = nullptr;
 };
 
diff --git a/editor/app/Windowing/Coordinator/EditorWindowWorkspaceCoordinator.cpp b/editor/app/Windowing/Coordinator/EditorWindowWorkspaceCoordinator.cpp
index 6afac72c..ac818eab 100644
--- a/editor/app/Windowing/Coordinator/EditorWindowWorkspaceCoordinator.cpp
+++ b/editor/app/Windowing/Coordinator/EditorWindowWorkspaceCoordinator.cpp
@@ -1,5 +1,6 @@
 #include "Windowing/Coordinator/EditorWindowWorkspaceCoordinator.h"
 
+#include "Windowing/Content/EditorWindowContentFactory.h"
 #include "Windowing/Content/EditorWindowContentController.h"
 #include "Windowing/Coordinator/EditorWindowLifecycleCoordinator.h"
 
@@ -88,9 +89,11 @@ std::string DescribeWindowSetState(const UIEditorWindowWorkspaceSet& windowSet)
 
 EditorWindowWorkspaceCoordinator::EditorWindowWorkspaceCoordinator(
     EditorWindowHost& hostRuntime,
-    EditorWindowSystem& windowSystem)
+    EditorWindowSystem& windowSystem,
+    EditorWindowContentFactory& contentFactory)
     : m_hostRuntime(hostRuntime),
-      m_windowSystem(windowSystem) {}
+      m_windowSystem(windowSystem),
+      m_contentFactory(contentFactory) {}
 
 EditorWindowWorkspaceCoordinator::~EditorWindowWorkspaceCoordinator() = default;
 
@@ -108,6 +111,8 @@ void EditorWindowWorkspaceCoordinator::RefreshWindowPresentation(EditorHostWindo
     if (!window.IsWorkspaceWindow()) {
         return;
     }
+
+    RefreshWorkspaceProjectionFromAuthoritativeState(window);
     RefreshWindowTitle(window);
 }
 
@@ -207,25 +212,6 @@ bool EditorWindowWorkspaceCoordinator::RefreshWorkspaceProjectionFromAuthoritati
     return true;
 }
 
-bool EditorWindowWorkspaceCoordinator::CommitLiveWindowMutation(
-    const EditorWindowWorkspaceMutationRequest& request) {
-    std::string error = {};
-    EditorWindowSynchronizationPlan plan = m_windowSystem.BuildPlanForWorkspaceMutationRequest(
-        request,
-        CaptureHostSnapshots(),
-        m_hostRuntime.GetPrimaryWindowTitle(),
-        error);
-    if (!plan.valid) {
-        LogRuntimeTrace(
-            "window",
-            "workspace live mutation rejected for window '" +
-                request.windowState.windowId + "': " + error);
-        return false;
-    }
-
-    return ApplySynchronizationPlan(plan);
-}
-
 void EditorWindowWorkspaceCoordinator::RefreshWindowTitle(EditorHostWindow& window) const {
     const EditorWorkspaceWindowProjection* projection = window.TryGetWorkspaceProjection();
     if (projection == nullptr || projection->windowTitle.empty()) {
@@ -378,9 +364,9 @@ bool EditorWindowWorkspaceCoordinator::ApplySynchronizationPlan(
                 createParams.initialHeight = action.create.placement.initialHeight;
             }
 
-            EditorHostWindow* const createdWindow = m_hostRuntime.CreateWorkspaceWindow(
-                    action.create.windowState,
-                    createParams);
+            EditorHostWindow* const createdWindow = m_hostRuntime.CreateHostWindow(
+                m_contentFactory.CreateWorkspaceContentController(action.create.windowState),
+                createParams);
             if (createdWindow == nullptr) {
                 for (const ExistingWindowSnapshot& snapshot : existingWindowSnapshots) {
                     restoreWindowSnapshot(snapshot);
@@ -853,15 +839,6 @@ bool EditorWindowWorkspaceCoordinator::TryProcessDetachRequest(
 void EditorWindowWorkspaceCoordinator::HandleWindowFrameTransferRequests(
     EditorHostWindow& sourceWindow,
     const EditorWindowFrameTransferRequests& transferRequests) {
-    if (transferRequests.workspace.workspaceMutation.has_value()) {
-        if (!CommitLiveWindowMutation(*transferRequests.workspace.workspaceMutation)) {
-            LogRuntimeTrace(
-                "window",
-                "failed to commit live workspace mutation for window '" +
-                    std::string(sourceWindow.GetWindowId()) + "'");
-        }
-    }
-
     if (!m_globalTabDragSession.active &&
         transferRequests.workspace.beginGlobalTabDrag.has_value() &&
         transferRequests.workspace.beginGlobalTabDrag->IsValid()) {
diff --git a/editor/app/Windowing/Coordinator/EditorWindowWorkspaceCoordinator.h b/editor/app/Windowing/Coordinator/EditorWindowWorkspaceCoordinator.h
index 0cfaf43b..ae743797 100644
--- a/editor/app/Windowing/Coordinator/EditorWindowWorkspaceCoordinator.h
+++ b/editor/app/Windowing/Coordinator/EditorWindowWorkspaceCoordinator.h
@@ -22,13 +22,15 @@ class EditorWindowSystem;
 
 namespace XCEngine::UI::Editor::App {
 
+class EditorWindowContentFactory;
 class EditorWindowLifecycleCoordinator;
 
 class EditorWindowWorkspaceCoordinator final {
 public:
     EditorWindowWorkspaceCoordinator(
         EditorWindowHost& hostRuntime,
-        EditorWindowSystem& windowSystem);
+        EditorWindowSystem& windowSystem,
+        EditorWindowContentFactory& contentFactory);
     ~EditorWindowWorkspaceCoordinator();
 
     void BindLifecycleCoordinator(EditorWindowLifecycleCoordinator& lifecycleCoordinator);
@@ -74,7 +76,6 @@ private:
         int preferredWidth = 0,
         int preferredHeight = 0);
     UIEditorWindowWorkspaceState BuildWindowStateForWindow(const EditorHostWindow& window) const;
-    bool CommitLiveWindowMutation(const EditorWindowWorkspaceMutationRequest& request);
     EditorWorkspaceWindowProjection BuildWorkspaceProjectionForState(
         const UIEditorWindowWorkspaceState& windowState,
         bool primary,
@@ -114,6 +115,7 @@ private:
 
     EditorWindowHost& m_hostRuntime;
     EditorWindowSystem& m_windowSystem;
+    EditorWindowContentFactory& m_contentFactory;
     EditorWindowLifecycleCoordinator* m_lifecycleCoordinator = nullptr;
     GlobalTabDragSession m_globalTabDragSession = {};
 };
diff --git a/editor/app/Windowing/EditorWindowManager.cpp b/editor/app/Windowing/EditorWindowManager.cpp
index aca4ad52..3a8d9df9 100644
--- a/editor/app/Windowing/EditorWindowManager.cpp
+++ b/editor/app/Windowing/EditorWindowManager.cpp
@@ -1,5 +1,7 @@
 #include "Windowing/EditorWindowManager.h"
 
+#include "Windowing/Content/EditorWindowContentController.h"
+#include "Windowing/Content/EditorWindowContentFactory.h"
 #include "Windowing/Coordinator/EditorWindowLifecycleCoordinator.h"
 #include "Windowing/Coordinator/EditorUtilityWindowCoordinator.h"
 #include "Windowing/Coordinator/EditorWindowWorkspaceCoordinator.h"
@@ -16,10 +18,16 @@ EditorWindowManager::EditorWindowManager(
     EditorWindowHostRuntimeServices& hostRuntime)
     : m_editorContext(editorContext)
     , m_hostRuntime(hostRuntime) {
+    m_contentFactory = CreateDefaultEditorWindowContentFactory(windowSystem);
     m_workspaceCoordinator =
-        std::make_unique<EditorWindowWorkspaceCoordinator>(m_hostRuntime, windowSystem);
+        std::make_unique<EditorWindowWorkspaceCoordinator>(
+            m_hostRuntime,
+            windowSystem,
+            *m_contentFactory);
     m_utilityCoordinator =
-        std::make_unique<EditorUtilityWindowCoordinator>(m_hostRuntime);
+        std::make_unique<EditorUtilityWindowCoordinator>(
+            m_hostRuntime,
+            *m_contentFactory);
     m_lifecycleCoordinator = std::make_unique<EditorWindowLifecycleCoordinator>(
         m_hostRuntime,
         *m_workspaceCoordinator);
@@ -33,8 +41,19 @@ EditorWindowManager::~EditorWindowManager() = default;
 EditorHostWindow* EditorWindowManager::CreateWorkspaceWindow(
     const UIEditorWindowWorkspaceState& windowState,
     const EditorWindowCreateParams& params) {
-    EditorHostWindow* const window =
-        m_hostRuntime.CreateWorkspaceWindow(windowState, params);
+    if (m_contentFactory == nullptr) {
+        return nullptr;
+    }
+    if (windowState.windowId.empty()) {
+        return nullptr;
+    }
+    if (!params.windowId.empty() && windowState.windowId != params.windowId) {
+        return nullptr;
+    }
+
+    EditorHostWindow* const window = m_hostRuntime.CreateHostWindow(
+        m_contentFactory->CreateWorkspaceContentController(windowState),
+        params);
     if (window != nullptr) {
         m_workspaceCoordinator->RegisterExistingWindow(*window);
     }
@@ -44,7 +63,13 @@ EditorHostWindow* EditorWindowManager::CreateWorkspaceWindow(
 EditorHostWindow* EditorWindowManager::CreateUtilityWindow(
     const EditorUtilityWindowDescriptor& descriptor,
     const EditorWindowCreateParams& params) {
-    EditorHostWindow* const window = m_hostRuntime.CreateUtilityWindow(descriptor, params);
+    if (m_contentFactory == nullptr) {
+        return nullptr;
+    }
+
+    EditorHostWindow* const window = m_hostRuntime.CreateHostWindow(
+        m_contentFactory->CreateUtilityContentController(descriptor),
+        params);
     if (window != nullptr) {
         m_workspaceCoordinator->RegisterExistingWindow(*window);
     }
diff --git a/editor/app/Windowing/EditorWindowManager.h b/editor/app/Windowing/EditorWindowManager.h
index 9bc3e245..42a1ce12 100644
--- a/editor/app/Windowing/EditorWindowManager.h
+++ b/editor/app/Windowing/EditorWindowManager.h
@@ -20,6 +20,7 @@ struct UIEditorWindowWorkspaceState;
 namespace XCEngine::UI::Editor::App {
 
 class EditorContext;
+class EditorWindowContentFactory;
 class EditorWindowHostRuntimeServices;
 class EditorWindowLifecycleCoordinator;
 class EditorUtilityWindowCoordinator;
@@ -72,6 +73,7 @@ private:
 
     EditorContext& m_editorContext;
     EditorWindowHostRuntimeServices& m_hostRuntime;
+    std::unique_ptr<EditorWindowContentFactory> m_contentFactory = {};
     std::unique_ptr<EditorWindowLifecycleCoordinator> m_lifecycleCoordinator = {};
     std::unique_ptr<EditorUtilityWindowCoordinator> m_utilityCoordinator = {};
     std::unique_ptr<EditorWindowWorkspaceCoordinator> m_workspaceCoordinator = {};
diff --git a/editor/app/Windowing/Frame/EditorWindowTransferRequests.h b/editor/app/Windowing/Frame/EditorWindowTransferRequests.h
index f68b2742..8afa0cce 100644
--- a/editor/app/Windowing/Frame/EditorWindowTransferRequests.h
+++ b/editor/app/Windowing/Frame/EditorWindowTransferRequests.h
@@ -7,9 +7,6 @@
 #include "Windowing/EditorWindowShared.h"
 #include "UtilityWindows/EditorUtilityWindowKind.h"
 
-#include "Windowing/System/EditorWindowSynchronizationPlan.h"
-#include <XCEditor/Workspace/UIEditorWindowWorkspaceModel.h>
-
 #include <optional>
 #include <string>
 
@@ -36,13 +33,11 @@ struct EditorWindowOpenUtilityWindowRequest {
 };
 
 struct EditorWorkspaceWindowFrameTransferRequests {
-    std::optional<EditorWindowWorkspaceMutationRequest> workspaceMutation = {};
     std::optional<EditorWindowPanelTransferRequest> beginGlobalTabDrag = {};
     std::optional<EditorWindowPanelTransferRequest> detachPanel = {};
 
     bool HasPendingRequests() const {
-        return workspaceMutation.has_value() ||
-            beginGlobalTabDrag.has_value() ||
+        return beginGlobalTabDrag.has_value() ||
             detachPanel.has_value();
     }
 };
diff --git a/editor/app/Windowing/Host/EditorWindowHostInterfaces.h b/editor/app/Windowing/Host/EditorWindowHostInterfaces.h
index 26037d67..1812c1a3 100644
--- a/editor/app/Windowing/Host/EditorWindowHostInterfaces.h
+++ b/editor/app/Windowing/Host/EditorWindowHostInterfaces.h
@@ -6,8 +6,8 @@
 #include "Windowing/Host/EditorWindowTypes.h"
 
 #include "Windowing/Presentation/EditorWorkspaceWindowProjection.h"
-#include <XCEditor/Workspace/UIEditorWindowWorkspaceModel.h>
 
+#include <memory>
 #include <string>
 #include <string_view>
 #include <vector>
@@ -27,8 +27,8 @@ struct UIEditorDockHostTabDropTarget;
 namespace XCEngine::UI::Editor::App {
 
 class EditorWindowHostCoordinator;
+class EditorWindowContentController;
 class EditorWindowDockHostBinding;
-struct EditorUtilityWindowDescriptor;
 
 class EditorHostWindow {
 public:
@@ -79,11 +79,8 @@ class EditorWindowHost {
 public:
     virtual ~EditorWindowHost() = default;
 
-    virtual EditorHostWindow* CreateWorkspaceWindow(
-        const UIEditorWindowWorkspaceState& windowState,
-        const EditorWindowCreateParams& params) = 0;
-    virtual EditorHostWindow* CreateUtilityWindow(
-        const EditorUtilityWindowDescriptor& descriptor,
+    virtual EditorHostWindow* CreateHostWindow(
+        std::unique_ptr<EditorWindowContentController> contentController,
         const EditorWindowCreateParams& params) = 0;
     virtual EditorHostWindow* FindWindowById(std::string_view windowId) = 0;
     virtual const EditorHostWindow* FindWindowById(std::string_view windowId) const = 0;
diff --git a/editor/app/Windowing/System/EditorWindowSynchronizationPlan.h b/editor/app/Windowing/System/EditorWindowSynchronizationPlan.h
index d35f7745..633cfc89 100644
--- a/editor/app/Windowing/System/EditorWindowSynchronizationPlan.h
+++ b/editor/app/Windowing/System/EditorWindowSynchronizationPlan.h
@@ -9,14 +9,6 @@
 
 namespace XCEngine::UI::Editor {
 
-struct EditorWindowWorkspaceMutationRequest {
-    UIEditorWindowWorkspaceState windowState = {};
-
-    bool IsValid() const {
-        return !windowState.windowId.empty();
-    }
-};
-
 struct EditorWindowHostSnapshot {
     std::string windowId = {};
     bool workspaceWindow = false;
diff --git a/editor/app/Windowing/System/EditorWindowSystem.cpp b/editor/app/Windowing/System/EditorWindowSystem.cpp
index a1b724fd..fd47fc47 100644
--- a/editor/app/Windowing/System/EditorWindowSystem.cpp
+++ b/editor/app/Windowing/System/EditorWindowSystem.cpp
@@ -56,6 +56,23 @@ const UIEditorWindowWorkspaceState* EditorWindowSystem::FindWindowState(
     return FindUIEditorWindowWorkspaceState(GetWindowSet(), windowId);
 }
 
+bool EditorWindowSystem::TryBuildLiveWindowWorkspaceController(
+    std::string_view windowId,
+    UIEditorWorkspaceController& outController) {
+    UIEditorWindowWorkspaceState* const windowState =
+        m_workspaceStore->FindMutableWindowState(windowId);
+    if (windowState == nullptr) {
+        outController = {};
+        return false;
+    }
+
+    outController = UIEditorWorkspaceController::BindToState(
+        GetPanelRegistry(),
+        windowState->workspace,
+        windowState->session);
+    return true;
+}
+
 UIEditorWindowWorkspaceController EditorWindowSystem::BuildWorkspaceMutationController() const {
     return UIEditorWindowWorkspaceController(GetPanelRegistry(), GetWindowSet());
 }
@@ -78,37 +95,6 @@ EditorWindowSynchronizationPlan EditorWindowSystem::BuildPlanForWindowSet(
         outError);
 }
 
-EditorWindowSynchronizationPlan EditorWindowSystem::BuildPlanForWorkspaceMutationRequest(
-    const EditorWindowWorkspaceMutationRequest& request,
-    const std::vector<EditorWindowHostSnapshot>& hostWindows,
-    std::wstring_view primaryWindowTitle,
-    std::string& outError) const {
-    if (!request.IsValid()) {
-        outError = "live window mutation request missing window id";
-        return {};
-    }
-
-    UIEditorWindowWorkspaceSet nextWindowSet = GetWindowSet();
-    UIEditorWindowWorkspaceState* existingState =
-        FindMutableUIEditorWindowWorkspaceState(nextWindowSet, request.windowState.windowId);
-    if (existingState == nullptr) {
-        outError =
-            "live window mutation references unknown window '" +
-            request.windowState.windowId + "'";
-        return {};
-    }
-
-    existingState->workspace = request.windowState.workspace;
-    existingState->session = request.windowState.session;
-    return BuildPlanForWindowSet(
-        nextWindowSet,
-        hostWindows,
-        primaryWindowTitle,
-        {},
-        {},
-        outError);
-}
-
 EditorWindowSynchronizationPlan EditorWindowSystem::BuildPlanForDestroyedWindow(
     std::string_view windowId,
     const std::vector<EditorWindowHostSnapshot>& hostWindows,
diff --git a/editor/app/Windowing/System/EditorWindowSystem.h b/editor/app/Windowing/System/EditorWindowSystem.h
index 141bd7a1..9fa42d03 100644
--- a/editor/app/Windowing/System/EditorWindowSystem.h
+++ b/editor/app/Windowing/System/EditorWindowSystem.h
@@ -1,6 +1,7 @@
 #pragma once
 
 #include "Windowing/System/EditorWindowSynchronizationPlan.h"
+#include <XCEditor/Workspace/UIEditorWorkspaceController.h>
 #include <XCEditor/Workspace/UIEditorWindowWorkspaceController.h>
 
 #include <memory>
@@ -35,6 +36,9 @@ public:
 
     const UIEditorWindowWorkspaceSet& GetWindowSet() const;
     const UIEditorWindowWorkspaceState* FindWindowState(std::string_view windowId) const;
+    bool TryBuildLiveWindowWorkspaceController(
+        std::string_view windowId,
+        UIEditorWorkspaceController& outController);
     UIEditorWindowWorkspaceController BuildWorkspaceMutationController() const;
     EditorWindowSynchronizationPlan BuildPlanForWindowSet(
         const UIEditorWindowWorkspaceSet& targetWindowSet,
@@ -43,11 +47,6 @@ public:
         std::string_view preferredNewWindowId,
         const EditorWindowSynchronizationPlacement& preferredPlacement,
         std::string& outError) const;
-    EditorWindowSynchronizationPlan BuildPlanForWorkspaceMutationRequest(
-        const EditorWindowWorkspaceMutationRequest& request,
-        const std::vector<EditorWindowHostSnapshot>& hostWindows,
-        std::wstring_view primaryWindowTitle,
-        std::string& outError) const;
     EditorWindowSynchronizationPlan BuildPlanForDestroyedWindow(
         std::string_view windowId,
         const std::vector<EditorWindowHostSnapshot>& hostWindows,
diff --git a/editor/app/Windowing/System/EditorWindowWorkspaceStore.cpp b/editor/app/Windowing/System/EditorWindowWorkspaceStore.cpp
index eee44147..bd49f534 100644
--- a/editor/app/Windowing/System/EditorWindowWorkspaceStore.cpp
+++ b/editor/app/Windowing/System/EditorWindowWorkspaceStore.cpp
@@ -38,4 +38,9 @@ bool EditorWindowWorkspaceStore::IsPrimaryWindowId(std::string_view windowId) co
     return !windowId.empty() && m_windowSet.primaryWindowId == windowId;
 }
 
+UIEditorWindowWorkspaceState* EditorWindowWorkspaceStore::FindMutableWindowState(
+    std::string_view windowId) {
+    return FindMutableUIEditorWindowWorkspaceState(m_windowSet, windowId);
+}
+
 } // namespace XCEngine::UI::Editor
diff --git a/editor/app/Windowing/System/EditorWindowWorkspaceStore.h b/editor/app/Windowing/System/EditorWindowWorkspaceStore.h
index 09c380b6..02d19c87 100644
--- a/editor/app/Windowing/System/EditorWindowWorkspaceStore.h
+++ b/editor/app/Windowing/System/EditorWindowWorkspaceStore.h
@@ -28,6 +28,7 @@ public:
     const UIEditorWindowWorkspaceSet& GetWindowSet() const {
         return m_windowSet;
     }
+    UIEditorWindowWorkspaceState* FindMutableWindowState(std::string_view windowId);
 
 private:
     UIEditorPanelRegistry m_panelRegistry = {};
diff --git a/editor/include/XCEditor/Workspace/UIEditorWorkspaceController.h b/editor/include/XCEditor/Workspace/UIEditorWorkspaceController.h
index b7bdb7be..1db3b2e7 100644
--- a/editor/include/XCEditor/Workspace/UIEditorWorkspaceController.h
+++ b/editor/include/XCEditor/Workspace/UIEditorWorkspaceController.h
@@ -83,6 +83,15 @@ public:
         UIEditorPanelRegistry panelRegistry,
         UIEditorWorkspaceModel workspace,
         UIEditorWorkspaceSession session);
+    UIEditorWorkspaceController(const UIEditorWorkspaceController& other);
+    UIEditorWorkspaceController& operator=(const UIEditorWorkspaceController& other);
+    UIEditorWorkspaceController(UIEditorWorkspaceController&&) noexcept = default;
+    UIEditorWorkspaceController& operator=(UIEditorWorkspaceController&&) noexcept = default;
+
+    static UIEditorWorkspaceController BindToState(
+        UIEditorPanelRegistry panelRegistry,
+        UIEditorWorkspaceModel& workspace,
+        UIEditorWorkspaceSession& session);
 
     const UIEditorPanelRegistry& GetPanelRegistry() const {
         return m_panelRegistry;
@@ -119,6 +128,8 @@ public:
     UIEditorWorkspaceCommandResult Dispatch(const UIEditorWorkspaceCommand& command);
 
 private:
+    void SyncBoundState();
+
     UIEditorWorkspaceCommandResult BuildResult(
         const UIEditorWorkspaceCommand& command,
         UIEditorWorkspaceCommandStatus status,
@@ -143,6 +154,8 @@ private:
     UIEditorWorkspaceSession m_baselineSession = {};
     UIEditorWorkspaceModel m_workspace = {};
     UIEditorWorkspaceSession m_session = {};
+    UIEditorWorkspaceModel* m_boundWorkspace = nullptr;
+    UIEditorWorkspaceSession* m_boundSession = nullptr;
 };
 
 UIEditorWorkspaceController BuildDefaultUIEditorWorkspaceController(
diff --git a/editor/src/Workspace/UIEditorWorkspaceController.cpp b/editor/src/Workspace/UIEditorWorkspaceController.cpp
index 76734b1c..7605058c 100644
--- a/editor/src/Workspace/UIEditorWorkspaceController.cpp
+++ b/editor/src/Workspace/UIEditorWorkspaceController.cpp
@@ -139,6 +139,53 @@ UIEditorWorkspaceController::UIEditorWorkspaceController(
     , m_session(std::move(session)) {
 }
 
+UIEditorWorkspaceController::UIEditorWorkspaceController(
+    const UIEditorWorkspaceController& other)
+    : m_panelRegistry(other.m_panelRegistry)
+    , m_baselineWorkspace(other.m_baselineWorkspace)
+    , m_baselineSession(other.m_baselineSession)
+    , m_workspace(other.m_workspace)
+    , m_session(other.m_session) {
+}
+
+UIEditorWorkspaceController& UIEditorWorkspaceController::operator=(
+    const UIEditorWorkspaceController& other) {
+    if (this == &other) {
+        return *this;
+    }
+
+    m_panelRegistry = other.m_panelRegistry;
+    m_baselineWorkspace = other.m_baselineWorkspace;
+    m_baselineSession = other.m_baselineSession;
+    m_workspace = other.m_workspace;
+    m_session = other.m_session;
+    m_boundWorkspace = nullptr;
+    m_boundSession = nullptr;
+    return *this;
+}
+
+UIEditorWorkspaceController UIEditorWorkspaceController::BindToState(
+    UIEditorPanelRegistry panelRegistry,
+    UIEditorWorkspaceModel& workspace,
+    UIEditorWorkspaceSession& session) {
+    UIEditorWorkspaceController controller(
+        std::move(panelRegistry),
+        workspace,
+        session);
+    controller.m_boundWorkspace = &workspace;
+    controller.m_boundSession = &session;
+    return controller;
+}
+
+void UIEditorWorkspaceController::SyncBoundState() {
+    if (m_boundWorkspace != nullptr) {
+        *m_boundWorkspace = m_workspace;
+    }
+    if (m_boundSession != nullptr) {
+        *m_boundSession = m_session;
+    }
+}
+
 UIEditorWorkspaceControllerValidationResult UIEditorWorkspaceController::ValidateState() const {
     const UIEditorPanelRegistryValidationResult registryValidation =
         ValidateUIEditorPanelRegistry(m_panelRegistry);
@@ -223,6 +270,8 @@ UIEditorWorkspaceCommandResult UIEditorWorkspaceController::FinalizeMutation(
             "Command produced invalid workspace state: " + validation.message);
     }
 
+    SyncBoundState();
+
     return BuildResult(
         command,
         UIEditorWorkspaceCommandStatus::Changed,
@@ -533,6 +582,8 @@ UIEditorWorkspaceLayoutOperationResult UIEditorWorkspaceController::RestoreLayou
             "Restored layout produced invalid controller state: " + validation.message);
     }
 
+    SyncBoundState();
+
     return BuildLayoutOperationResult(
         UIEditorWorkspaceLayoutOperationStatus::Changed,
         "Layout restored.");
@@ -595,6 +646,8 @@ UIEditorWorkspaceLayoutOperationResult UIEditorWorkspaceController::SetSplitRati
             "Split ratio update produced invalid controller state: " + postValidation.message);
     }
 
+    SyncBoundState();
+
     return BuildLayoutOperationResult(
         UIEditorWorkspaceLayoutOperationStatus::Changed,
         "Split ratio updated.");
@@ -701,6 +754,8 @@ UIEditorWorkspaceLayoutOperationResult UIEditorWorkspaceController::MoveTabToSta
             "MoveTabToStack produced invalid controller state: " + postValidation.message);
     }
 
+    SyncBoundState();
+
     return BuildLayoutOperationResult(
         UIEditorWorkspaceLayoutOperationStatus::Changed,
         "Tab moved to target stack.");
@@ -796,6 +851,8 @@ UIEditorWorkspaceLayoutOperationResult UIEditorWorkspaceController::DockTabRelat
             "DockTabRelative produced invalid controller state: " + postValidation.message);
     }
 
+    SyncBoundState();
+
     return BuildLayoutOperationResult(
         UIEditorWorkspaceLayoutOperationStatus::Changed,
         "Tab docked relative to target stack.");
diff --git a/tests/UI/Editor/unit/test_editor_window_synchronization_planner.cpp b/tests/UI/Editor/unit/test_editor_window_synchronization_planner.cpp
index e5509f0b..7ed0ba7e 100644
--- a/tests/UI/Editor/unit/test_editor_window_synchronization_planner.cpp
+++ b/tests/UI/Editor/unit/test_editor_window_synchronization_planner.cpp
@@ -20,12 +20,12 @@ using XCEngine::UI::Editor::EditorWindowHostSnapshot;
 using XCEngine::UI::Editor::EditorWindowSynchronizationActionKind;
 using XCEngine::UI::Editor::EditorWindowSynchronizationPlannerInput;
 using XCEngine::UI::Editor::EditorWindowSystem;
-using XCEngine::UI::Editor::EditorWindowWorkspaceMutationRequest;
 using XCEngine::UI::Editor::FindUIEditorWindowWorkspaceState;
 using XCEngine::UI::Editor::UIEditorWorkspaceCommand;
 using XCEngine::UI::Editor::UIEditorWorkspaceCommandKind;
 using XCEngine::UI::Editor::UIEditorWorkspaceCommandStatus;
 using XCEngine::UI::Editor::UIEditorPanelRegistry;
+using XCEngine::UI::Editor::UIEditorWorkspaceController;
 using XCEngine::UI::Editor::UIEditorWindowWorkspaceController;
 using XCEngine::UI::Editor::UIEditorWindowWorkspaceOperationStatus;
 using XCEngine::UI::Editor::UIEditorWorkspaceModel;
@@ -363,7 +363,7 @@ TEST(EditorWindowSynchronizationPlannerTest, RejectsInvalidTargetWindowSet) {
     EXPECT_FALSE(error.empty());
 }
 
-TEST(EditorWindowSynchronizationPlannerTest, LiveWindowMutationBuildsCommitPlanWithoutPlatformWriteback) {
+TEST(EditorWindowSynchronizationPlannerTest, LiveWindowControllerWritesThroughToAuthoritativeState) {
     EditorWindowSystem system = BuildSystem();
     const auto workspaceController =
         BuildDefaultUIEditorWorkspaceController(BuildPanelRegistry(), BuildWorkspace());
@@ -373,40 +373,35 @@ TEST(EditorWindowSynchronizationPlannerTest, LiveWindowMutationBuildsCommitPlanW
         BuildWindowState("main", workspaceController),
         error)) << error;
 
-    auto liveController = workspaceController;
+    UIEditorWorkspaceController liveController = {};
+    ASSERT_TRUE(system.TryBuildLiveWindowWorkspaceController("main", liveController));
     const auto commandResult = liveController.Dispatch(
         UIEditorWorkspaceCommand{
             .kind = UIEditorWorkspaceCommandKind::ActivatePanel,
             .panelId = "doc-b",
         });
     ASSERT_EQ(commandResult.status, UIEditorWorkspaceCommandStatus::Changed);
+    EXPECT_EQ(system.GetWindowSet().windows.front().workspace.activePanelId, "doc-b");
 
-    EditorWindowWorkspaceMutationRequest request = {};
-    request.windowState = BuildWindowState("main", liveController);
-
-    auto plan = system.BuildPlanForWorkspaceMutationRequest(
-        request,
-        {
-            BuildWorkspaceSnapshot(
-                "main",
-                true,
-                liveController,
-                L"Main Scene - XCEngine Editor"),
+    auto plan = system.BuildSynchronizationPlan(
+        EditorWindowSynchronizationPlannerInput{
+            .targetWindowSet = &system.GetWindowSet(),
+            .primaryWindowTitle = L"Main Scene - XCEngine Editor",
+            .hostWindows = {
+                BuildWorkspaceSnapshot(
+                    "main",
+                    true,
+                    liveController,
+                    L"Main Scene - XCEngine Editor"),
+            },
         },
-        L"Main Scene - XCEngine Editor",
         error);
 
     ASSERT_TRUE(plan.valid) << error;
     EXPECT_TRUE(plan.actions.empty());
-    const auto* mutatedState = FindUIEditorWindowWorkspaceState(plan.targetWindowSet, "main");
-    ASSERT_NE(mutatedState, nullptr);
-    EXPECT_EQ(mutatedState->workspace.activePanelId, "doc-b");
-
-    ASSERT_TRUE(system.CommitSynchronizationPlan(plan, error)) << error;
-    EXPECT_EQ(system.GetWindowSet().windows.front().workspace.activePanelId, "doc-b");
 }
 
-TEST(EditorWindowSynchronizationPlannerTest, WorkspaceMutationRequestBuildsCommitPlanFromExplicitPayload) {
+TEST(EditorWindowSynchronizationPlannerTest, LiveWindowControllerCopyDoesNotWriteThroughToAuthoritativeState) {
     EditorWindowSystem system = BuildSystem();
     const auto workspaceController =
         BuildDefaultUIEditorWorkspaceController(BuildPanelRegistry(), BuildWorkspace());
@@ -416,44 +411,21 @@ TEST(EditorWindowSynchronizationPlannerTest, WorkspaceMutationRequestBuildsCommi
         BuildWindowState("main", workspaceController),
         error)) << error;
 
-    auto liveController = workspaceController;
-    const auto commandResult = liveController.Dispatch(
+    UIEditorWorkspaceController liveController = {};
+    ASSERT_TRUE(system.TryBuildLiveWindowWorkspaceController("main", liveController));
+    UIEditorWorkspaceController previewController = liveController;
+
+    const auto commandResult = previewController.Dispatch(
         UIEditorWorkspaceCommand{
             .kind = UIEditorWorkspaceCommandKind::ActivatePanel,
             .panelId = "doc-b",
         });
     ASSERT_EQ(commandResult.status, UIEditorWorkspaceCommandStatus::Changed);
-
-    EditorWindowWorkspaceMutationRequest request = {};
-    request.windowState.windowId = "main";
-    request.windowState.workspace = liveController.GetWorkspace();
-    request.windowState.session = liveController.GetSession();
-
-    auto plan = system.BuildPlanForWorkspaceMutationRequest(
-        request,
-        {
-            BuildWorkspaceSnapshot(
-                "main",
-                true,
-                workspaceController,
-                L"Main Scene - XCEngine Editor"),
-        },
-        L"Main Scene - XCEngine Editor",
-        error);
-
-    ASSERT_TRUE(plan.valid) << error;
-    ASSERT_EQ(plan.actions.size(), 1u);
-    EXPECT_EQ(plan.actions[0].kind, EditorWindowSynchronizationActionKind::UpdateWorkspaceWindow);
-    EXPECT_EQ(plan.actions[0].update.windowState.windowId, "main");
-    const auto* mutatedState = FindUIEditorWindowWorkspaceState(plan.targetWindowSet, "main");
-    ASSERT_NE(mutatedState, nullptr);
-    EXPECT_EQ(mutatedState->workspace.activePanelId, "doc-b");
-
-    ASSERT_TRUE(system.CommitSynchronizationPlan(plan, error)) << error;
-    EXPECT_EQ(system.GetWindowSet().windows.front().workspace.activePanelId, "doc-b");
+    EXPECT_EQ(previewController.GetWorkspace().activePanelId, "doc-b");
+    EXPECT_EQ(system.GetWindowSet().windows.front().workspace.activePanelId, "doc-a");
 }
 
-TEST(EditorWindowSynchronizationPlannerTest, WorkspaceMutationRequestRejectsUnknownWindowId) {
+TEST(EditorWindowSynchronizationPlannerTest, TryBuildLiveWindowWorkspaceControllerRejectsUnknownWindowId) {
     EditorWindowSystem system = BuildSystem();
     const auto workspaceController =
         BuildDefaultUIEditorWorkspaceController(BuildPanelRegistry(), BuildWorkspace());
@@ -463,25 +435,8 @@ TEST(EditorWindowSynchronizationPlannerTest, WorkspaceMutationRequestRejectsUnkn
         BuildWindowState("main", workspaceController),
         error)) << error;
 
-    EditorWindowWorkspaceMutationRequest request = {};
-    request.windowState.windowId = "missing-window";
-    request.windowState.workspace = workspaceController.GetWorkspace();
-    request.windowState.session = workspaceController.GetSession();
-
-    auto plan = system.BuildPlanForWorkspaceMutationRequest(
-        request,
-        {
-            BuildWorkspaceSnapshot(
-                "main",
-                true,
-                workspaceController,
-                L"Main Scene - XCEngine Editor"),
-        },
-        L"Main Scene - XCEngine Editor",
-        error);
-
-    EXPECT_FALSE(plan.valid);
-    EXPECT_NE(error.find("missing-window"), std::string::npos);
+    UIEditorWorkspaceController liveController = {};
+    EXPECT_FALSE(system.TryBuildLiveWindowWorkspaceController("missing-window", liveController));
 }
 
 TEST(EditorWindowSynchronizationPlannerTest, DestroyedPrimaryWindowProducesCloseActionsForRemainingDetachedWindows) {