diff --git a/docs/NEXT_ROADMAP.md b/docs/NEXT_ROADMAP.md
index e322392..bea076a 100644
--- a/docs/NEXT_ROADMAP.md
+++ b/docs/NEXT_ROADMAP.md
@@ -4892,5 +4892,67 @@ ThemeResourceHelper에 5개 정적 필드 추가:
 
 ---
 
-최종 업데이트: 2026-04-03 (Phase 22~52 + Phase 17-UI-A~B 구현 완료)
+## Phase 17-UI-C — AgentSessionHeaderBar UserControl 통합 (v1.8.0) ✅ 완료
+
+> **목표**: 기존 Row 1 서브 바의 모델·Plan·권한 칩을 `AgentSessionHeaderBar` UserControl로 교체.
+> 투명 배경으로 기존 레이아웃에 임베드. 이벤트 기반 위임으로 ChatWindow 기존 로직 재사용.
+
+### 변경 파일
+
+| 파일 | 변경 내용 |
+|------|----------|
+| `AgentSessionHeaderBar.xaml` | 외부 Border를 `Background="Transparent" BorderThickness="0"`으로 수정. 높이 42→38px. `x:Name="PlanIcon"`, `x:Name="PermIcon"` 추가. |
+| `AgentSessionHeaderBar.xaml.cs` | `SetPlanMode()`: `PlanIcon` x:Name 직접 참조. `ChipPermission_Click`: 이벤트 발행만 (팝업은 ChatWindow 처리). `SetPermissionMode()`: PermIcon 색상 업데이트. |
+| `ChatWindow.xaml` | Row 1 우측에서 `ModelHeaderChip`, `BtnPlanMode`, `PermissionHeaderChip` 제거 → `<ctrl:AgentSessionHeaderBar x:Name="SessionHeaderBar"/>` 추가. |
+| `ChatWindow.SessionHeaderBar.cs` | 신규: `InitSessionHeaderBar()` — ModelChipClicked·PlanModeChanged·PermissionModeChanged·SettingsRequested 이벤트 구독. |
+| `ChatWindow.ModelSelector.cs` | `UpdateModelLabel()`: `SessionHeaderBar?.SetModel()` 동기화. |
+| `ChatWindow.PermissionMenu.cs` | `UpdatePermissionUI()`: `SessionHeaderBar?.SetPermissionMode()` 동기화. |
+| `ChatWindow.TabSwitching.cs` | `UpdateTabUI()`: `SessionHeaderBar?.SetTabLabel()` 동기화. `UpdatePlanModeUI()`: SessionHeaderBar 전용으로 단순화. |
+| `ChatWindow.xaml.cs` | Loaded: `InitSessionHeaderBar()` 호출 추가. |
+
+- **빌드**: 경고 0, 오류 0
+
+---
+
+## Phase 17-UI-D — AgentSidebarView UserControl 통합 (v1.8.0) ✅ 완료
+
+> **목표**: 기존 `SidebarPanel` Border(인라인 XAML 110줄)를 `AgentSidebarView` UserControl로 교체.
+> 34개 기존 ChatWindow 파셜 파일이 사이드바 내부 요소를 무수정으로 참조할 수 있도록 프록시 패턴 적용.
+
+### 변경 파일
+
+| 파일 | 변경 내용 |
+|------|----------|
+| `AgentSidebarView.xaml` | 7행 구조로 재작성: 헤더(로고+새대화) / 탭세그먼트 / 검색 / 카테고리드롭다운 / 대화목록 / 삭제 / 사용자계정. |
+| `AgentSidebarView.xaml.cs` | 완전 재작성: `internal` 프록시 프로퍼티 8개 + `SidebarTabChanged`/`NewChatRequested`/`DeleteAllRequested`/`CategoryDropClicked`/`SearchTextChanged` 이벤트. |
+| `ChatWindow.xaml` | `<Border x:Name="SidebarPanel">` 인라인 110줄 → `<ctrl:AgentSidebarView x:Name="Sidebar"/>` 1줄 대체. |
+| `ChatWindow.SidebarCompat.cs` | 신규: 8개 계산 프로퍼티(`ConversationPanel`, `SearchBox`, `CategoryIcon`, `CategoryLabel`, `BtnCategoryDrop`, `UserInitialSidebar`, `UserNameText`, `UserPcText`) + `InitSidebarEvents()`. |
+| `ChatWindow.PermissionMenu.cs` | `BtnToggleSidebar_Click()`: `SidebarPanel.Visibility` → `Sidebar.Visibility`. `PermissionHeaderChip_Click()`: `PermissionHeaderChip` → `SessionHeaderBar`. |
+| `ChatWindow.TabSwitching.cs` | 탭 핸들러 3개: `Sidebar?.SetActiveTab()` 동기화 추가. `UpdatePlanModeUI()`: 죽은 코드 제거. |
+| `ChatWindow.xaml.cs` | Loaded: `InitSidebarEvents()` 호출 추가. |
+
+- **빌드**: 경고 0, 오류 0
+
+---
+
+## Phase 17-UI-E — AgentInputArea 툴바 통합 (v1.8.0) ✅ 완료
+
+> **목표**: `AgentInputArea` UserControl에 `IsToolbarOnly` 모드 추가.
+> 기존 InputBox 위에 @ / 스킬 / 첨부 툴바 행을 추가하여 Claude.ai 스타일 입력 경험 제공.
+
+### 변경 파일
+
+| 파일 | 변경 내용 |
+|------|----------|
+| `AgentInputArea.xaml` | `x:Name="OuterBorder"`, `x:Name="InputTextBoxRow"`, `x:Name="ChipsSendRow"` 추가. |
+| `AgentInputArea.xaml.cs` | `IsToolbarOnly` 의존성 프로퍼티 추가. `ApplyToolbarOnlyMode()`: TextBox/칩 행 Collapsed, 외부 Border 투명화. |
+| `ChatWindow.xaml` | InputBorder Grid에 Row 0 추가(`ctrl:AgentInputArea x:Name="InputToolbar" IsToolbarOnly="True"`). 기존 Row 0→1, 1→2, 2→3 시프트. |
+| `ChatWindow.InputToolbar.cs` | 신규: `InitInputToolbar()` — MentionRequested(@삽입), SkillRequested(/삽입), AttachRequested(BtnAttach_Click 위임). |
+| `ChatWindow.xaml.cs` | Loaded: `InitInputToolbar()` 호출 추가. |
+
+- **빌드**: 경고 0, 오류 0
+
+---
+
+최종 업데이트: 2026-04-03 (Phase 22~52 + Phase 17-UI-A~E 구현 완료)
 
diff --git a/src/AxCopilot/Views/ChatWindow.InputToolbar.cs b/src/AxCopilot/Views/ChatWindow.InputToolbar.cs
new file mode 100644
index 0000000..043e875
--- /dev/null
+++ b/src/AxCopilot/Views/ChatWindow.InputToolbar.cs
@@ -0,0 +1,37 @@
+using System.Windows;
+
+namespace AxCopilot.Views;
+
+/// <summary>
+/// Phase 17-UI-E: AgentInputArea InputToolbar 이벤트 연결.
+/// @ 멘션, / 스킬, 📎 첨부 버튼을 기존 ChatWindow 동작에 위임합니다.
+/// </summary>
+public partial class ChatWindow
+{
+    private void InitInputToolbar()
+    {
+        if (InputToolbar == null) return;
+
+        // @ 멘션 클릭 → InputBox에 "@" 삽입 후 포커스
+        InputToolbar.MentionRequested += (_, _) =>
+        {
+            InputBox.Text += "@";
+            InputBox.CaretIndex = InputBox.Text.Length;
+            InputBox.Focus();
+        };
+
+        // / 스킬 클릭 → InputBox에 "/" 삽입 후 포커스 (슬래시 팝업 트리거)
+        InputToolbar.SkillRequested += (_, _) =>
+        {
+            InputBox.Text += "/";
+            InputBox.CaretIndex = InputBox.Text.Length;
+            InputBox.Focus();
+        };
+
+        // 첨부 클릭 → 기존 파일 첨부 다이얼로그 (BtnAttach_Click 대응)
+        InputToolbar.AttachRequested += (_, _) =>
+        {
+            BtnAttach_Click(InputToolbar, new RoutedEventArgs());
+        };
+    }
+}
diff --git a/src/AxCopilot/Views/ChatWindow.ModelSelector.cs b/src/AxCopilot/Views/ChatWindow.ModelSelector.cs
index 7f39065..3554722 100644
--- a/src/AxCopilot/Views/ChatWindow.ModelSelector.cs
+++ b/src/AxCopilot/Views/ChatWindow.ModelSelector.cs
@@ -141,9 +141,8 @@ public partial class ChatWindow
         };
         var modelName = GetCurrentModelDisplayName();
         ModelLabel.Text = $"{serviceLabel} · {modelName}";
-        // Phase 17-UI-B: 헤더 바 모델 칩도 갱신
-        if (ModelHeaderLabel != null)
-            ModelHeaderLabel.Text = $"{serviceLabel} · {modelName}";
+        // Phase 17-UI-C: SessionHeaderBar 모델 칩 동기화
+        SessionHeaderBar?.SetModel($"{serviceLabel} · {modelName}");
     }
 
     private void BtnModelSelector_Click(object sender, RoutedEventArgs e)
diff --git a/src/AxCopilot/Views/ChatWindow.PermissionMenu.cs b/src/AxCopilot/Views/ChatWindow.PermissionMenu.cs
index 1592716..e74aa4c 100644
--- a/src/AxCopilot/Views/ChatWindow.PermissionMenu.cs
+++ b/src/AxCopilot/Views/ChatWindow.PermissionMenu.cs
@@ -101,12 +101,12 @@ public partial class ChatWindow
             AutoPermissionWarning.Visibility = Visibility.Collapsed;
     }
 
-    /// <summary>Phase 17-UI-B: 헤더 바 권한 칩 클릭 — 권한 팝업을 칩 위치에 표시.</summary>
+    /// <summary>Phase 17-UI-C: SessionHeaderBar 권한 칩 클릭 — 권한 팝업을 SessionHeaderBar 위치에 표시.</summary>
     private void PermissionHeaderChip_Click(object sender, RoutedEventArgs e)
     {
         if (PermissionPopup == null) return;
-        // 팝업 기준점을 헤더 칩으로 변경
-        PermissionPopup.PlacementTarget = PermissionHeaderChip;
+        // 팝업 기준점을 SessionHeaderBar로 변경 (PermissionHeaderChip → SessionHeaderBar로 대체)
+        PermissionPopup.PlacementTarget = SessionHeaderBar;
         PermissionPopup.Placement = System.Windows.Controls.Primitives.PlacementMode.Bottom;
         BtnPermission_Click(sender, e);
     }
@@ -116,8 +116,8 @@ public partial class ChatWindow
         if (PermissionLabel == null || PermissionIcon == null) return;
         var perm = Llm.FilePermission;
         PermissionLabel.Text = perm;
-        // Phase 17-UI-B: 헤더 칩 텍스트도 갱신
-        if (PermissionHeaderLabel != null) PermissionHeaderLabel.Text = perm;
+        // Phase 17-UI-C: SessionHeaderBar 권한 칩 동기화
+        SessionHeaderBar?.SetPermissionMode(perm);
         PermissionIcon.Text = perm switch
         {
             "Auto" => "\uE73E",
@@ -466,7 +466,7 @@ public partial class ChatWindow
             // 사이드바 열기, 아이콘 바 숨기기
             IconBarColumn.Width = new GridLength(0);
             IconBarPanel.Visibility = Visibility.Collapsed;
-            SidebarPanel.Visibility = Visibility.Visible;
+            Sidebar.Visibility = Visibility.Visible;
             ToggleSidebarIcon.Text = "\uE76B";
             AnimateSidebar(0, 270, () => SidebarColumn.MinWidth = 200);
         }
@@ -477,7 +477,7 @@ public partial class ChatWindow
             ToggleSidebarIcon.Text = "\uE76C";
             AnimateSidebar(270, 0, () =>
             {
-                SidebarPanel.Visibility = Visibility.Collapsed;
+                Sidebar.Visibility = Visibility.Collapsed;
                 IconBarColumn.Width = new GridLength(52);
                 IconBarPanel.Visibility = Visibility.Visible;
             });
diff --git a/src/AxCopilot/Views/ChatWindow.SessionHeaderBar.cs b/src/AxCopilot/Views/ChatWindow.SessionHeaderBar.cs
new file mode 100644
index 0000000..4dfa090
--- /dev/null
+++ b/src/AxCopilot/Views/ChatWindow.SessionHeaderBar.cs
@@ -0,0 +1,38 @@
+using System.Windows;
+
+namespace AxCopilot.Views;
+
+/// <summary>
+/// Phase 17-UI-C: AgentSessionHeaderBar 이벤트 연결 및 상태 동기화.
+/// SessionHeaderBar(UserControl) ↔ ChatWindow 기존 로직 브리지.
+/// </summary>
+public partial class ChatWindow
+{
+    /// <summary>Loaded 핸들러에서 호출 — SessionHeaderBar 이벤트 연결.</summary>
+    private void InitSessionHeaderBar()
+    {
+        // 모델 칩 클릭 → 기존 BtnModelSelector_Click 재사용
+        SessionHeaderBar.ModelChipClicked += (_, _) =>
+            BtnModelSelector_Click(SessionHeaderBar, new RoutedEventArgs());
+
+        // Plan 모드 순환 → 설정 저장 + 기존 UI 동기화
+        SessionHeaderBar.PlanModeChanged += (_, mode) =>
+        {
+            Llm.PlanMode = mode;
+            _settings.Save();
+            UpdatePlanModeUI(); // SessionHeaderBar.SetPlanMode()가 내부서 호출됨
+        };
+
+        // 권한 칩 클릭 → 권한 팝업을 SessionHeaderBar 위치에 표시
+        SessionHeaderBar.PermissionModeChanged += (_, _) =>
+        {
+            if (PermissionPopup == null) return;
+            PermissionPopup.PlacementTarget = SessionHeaderBar;
+            PermissionPopup.Placement = System.Windows.Controls.Primitives.PlacementMode.Bottom;
+            BtnPermission_Click(SessionHeaderBar, new RoutedEventArgs());
+        };
+
+        // 설정 버튼 → 기존 ToggleSettingsPanel() 재사용
+        SessionHeaderBar.SettingsRequested += (_, _) => ToggleSettingsPanel();
+    }
+}
diff --git a/src/AxCopilot/Views/ChatWindow.SidebarCompat.cs b/src/AxCopilot/Views/ChatWindow.SidebarCompat.cs
new file mode 100644
index 0000000..f468a6b
--- /dev/null
+++ b/src/AxCopilot/Views/ChatWindow.SidebarCompat.cs
@@ -0,0 +1,80 @@
+using System.Windows;
+using System.Windows.Controls;
+using AxCopilot.Views.Controls;
+
+namespace AxCopilot.Views;
+
+/// <summary>
+/// Phase 17-UI-D: AgentSidebarView 프록시 어댑터.
+/// 34개 기존 ChatWindow 파셜 파일이 사이드바 내부 요소를 그대로 참조할 수 있도록
+/// 계산 프로퍼티(computed property)로 위임합니다.
+/// </summary>
+public partial class ChatWindow
+{
+    // ── 사이드바 내부 요소 프록시 (기존 코드 무수정 호환) ─────────────────
+
+    /// <summary>대화 목록 StackPanel — RefreshConversationList 등에서 직접 사용.</summary>
+    private StackPanel ConversationPanel => Sidebar.SidebarConversationPanel;
+
+    /// <summary>검색 TextBox — SearchBox_TextChanged 및 검색 필터링에서 사용.</summary>
+    private TextBox SearchBox => Sidebar.SidebarSearchBox;
+
+    /// <summary>카테고리 아이콘 TextBlock — UpdateCategoryLabel()에서 사용.</summary>
+    private TextBlock CategoryIcon => Sidebar.SidebarCategoryIcon;
+
+    /// <summary>카테고리 레이블 TextBlock — UpdateCategoryLabel()에서 사용.</summary>
+    private TextBlock CategoryLabel => Sidebar.SidebarCategoryLabel;
+
+    /// <summary>카테고리 드롭다운 Border — 팝업 PlacementTarget으로 사용.</summary>
+    private Border BtnCategoryDrop => Sidebar.SidebarCategoryDropTarget;
+
+    /// <summary>사용자 이니셜 TextBlock — SetupUserInfo()에서 사용.</summary>
+    private TextBlock UserInitialSidebar => Sidebar.SidebarUserInitial;
+
+    /// <summary>사용자 이름 TextBlock — SetupUserInfo()에서 사용.</summary>
+    private TextBlock UserNameText => Sidebar.SidebarUserName;
+
+    /// <summary>사용자 PC 텍스트 TextBlock — SetupUserInfo()에서 사용.</summary>
+    private TextBlock UserPcText => Sidebar.SidebarUserPc;
+
+    // ── 사이드바 이벤트 구독 초기화 ──────────────────────────────────────
+
+    private void InitSidebarEvents()
+    {
+        // 탭 전환: 사이드바 탭 클릭 → 메인 탭 RadioButton 동기화
+        Sidebar.SidebarTabChanged += (_, tab) =>
+        {
+            _activeTab = tab;
+            switch (tab)
+            {
+                case "Cowork": TabCowork.IsChecked = true; break;
+                case "Code":   TabCode.IsChecked   = true; break;
+                default:       TabChat.IsChecked   = true; break;
+            }
+        };
+
+        // 새 대화 요청
+        Sidebar.NewChatRequested += (_, _) =>
+        {
+            BtnNewChat_Click(Sidebar, new RoutedEventArgs());
+        };
+
+        // 전체 삭제 요청
+        Sidebar.DeleteAllRequested += (_, _) =>
+        {
+            BtnDeleteAll_Click(Sidebar, new RoutedEventArgs());
+        };
+
+        // 카테고리 드롭다운 클릭
+        Sidebar.CategoryDropClicked += (_, _) =>
+        {
+            BtnCategoryDrop_Click(Sidebar, new RoutedEventArgs());
+        };
+
+        // 검색어 변경 — SearchBox_TextChanged는 기존 코드가 TextBox sender로 받음
+        Sidebar.SearchTextChanged += (sender, e) =>
+        {
+            SearchBox_TextChanged(sender, e);
+        };
+    }
+}
diff --git a/src/AxCopilot/Views/ChatWindow.TabSwitching.cs b/src/AxCopilot/Views/ChatWindow.TabSwitching.cs
index a063d67..8a9ee1b 100644
--- a/src/AxCopilot/Views/ChatWindow.TabSwitching.cs
+++ b/src/AxCopilot/Views/ChatWindow.TabSwitching.cs
@@ -1,6 +1,5 @@
 using System.Windows;
 using System.Windows.Controls;
-using System.Windows.Media;
 using AxCopilot.Services;
 
 namespace AxCopilot.Views;
@@ -64,6 +63,7 @@ public partial class ChatWindow
         SaveCurrentTabConversationId();
         _activeTab = "Chat";
         _selectedCategory = ""; UpdateCategoryLabel();
+        Sidebar?.SetActiveTab("Chat");  // Phase 17-UI-D: 사이드바 탭 하이라이트 동기화
         UpdateTabUI();
         UpdatePlanModeUI();
     }
@@ -75,6 +75,7 @@ public partial class ChatWindow
         SaveCurrentTabConversationId();
         _activeTab = "Cowork";
         _selectedCategory = ""; UpdateCategoryLabel();
+        Sidebar?.SetActiveTab("Cowork"); // Phase 17-UI-D: 사이드바 탭 하이라이트 동기화
         UpdateTabUI();
         UpdatePlanModeUI();
     }
@@ -86,6 +87,7 @@ public partial class ChatWindow
         SaveCurrentTabConversationId();
         _activeTab = "Code";
         _selectedCategory = ""; UpdateCategoryLabel();
+        Sidebar?.SetActiveTab("Code");   // Phase 17-UI-D: 사이드바 탭 하이라이트 동기화
         UpdateTabUI();
         UpdatePlanModeUI();
     }
@@ -143,6 +145,9 @@ public partial class ChatWindow
         // 현재 대화를 해당 탭 대화로 전환
         SwitchToTabConversation();
 
+        // Phase 17-UI-C: SessionHeaderBar 탭 레이블 동기화
+        SessionHeaderBar?.SetTabLabel(_activeTab);
+
         // Phase 17-UI: 설정 패널이 열려 있으면 탭 전환 시 패널 업데이트
         if (SettingsPanel?.IsOpen == true)
             SettingsPanel.UpdateActiveTab(_activeTab);
@@ -167,23 +172,8 @@ public partial class ChatWindow
     private void UpdatePlanModeUI()
     {
         var planMode = Llm.PlanMode ?? "off";
-        if (PlanModeValue == null) return;
-
-        PlanModeValue.Text = planMode switch
-        {
-            "auto" => "Auto",
-            "always" => "Always",
-            _ => "Off"
-        };
-        var isActive = planMode != "off";
-        var activeBrush = ThemeResourceHelper.Accent(this);
-        var secondaryBrush = ThemeResourceHelper.Secondary(this);
-        if (PlanModeIcon != null) PlanModeIcon.Foreground = isActive ? activeBrush : secondaryBrush;
-        if (PlanModeLabel != null) PlanModeLabel.Foreground = isActive ? activeBrush : secondaryBrush;
-        if (BtnPlanMode != null)
-            BtnPlanMode.Background = isActive
-                ? new SolidColorBrush(Color.FromArgb(0x1A, 0x4B, 0x5E, 0xFC))
-                : Brushes.Transparent;
+        // Phase 17-UI-C: SessionHeaderBar가 Plan 칩을 완전히 대체함
+        SessionHeaderBar?.SetPlanMode(planMode);
     }
 
     private void SwitchToTabConversation()
diff --git a/src/AxCopilot/Views/ChatWindow.xaml b/src/AxCopilot/Views/ChatWindow.xaml
index 19f9e8e..57edadf 100644
--- a/src/AxCopilot/Views/ChatWindow.xaml
+++ b/src/AxCopilot/Views/ChatWindow.xaml
@@ -185,121 +185,9 @@
             </Border>
 
             <!-- ══════════════════════════════════════════════════════ -->
-            <!-- 좌측: 사이드바                                          -->
+            <!-- 좌측: 사이드바 (Phase 17-UI-D: AgentSidebarView UserControl) -->
             <!-- ══════════════════════════════════════════════════════ -->
-            <Border x:Name="SidebarPanel" Grid.Column="1"
-                    Background="{DynamicResource ItemBackground}">
-                <Grid>
-                    <Grid.RowDefinitions>
-                        <RowDefinition Height="54"/>
-                        <RowDefinition Height="Auto"/>
-                        <RowDefinition Height="Auto"/>
-                        <RowDefinition Height="*"/>
-                        <RowDefinition Height="Auto"/>
-                        <RowDefinition Height="52"/>
-                    </Grid.RowDefinitions>
-
-                    <!-- 헤더: 로고 + 새 대화 -->
-                    <Grid Grid.Row="0" Margin="16,0">
-                        <StackPanel Orientation="Horizontal" VerticalAlignment="Center">
-                            <Border Background="{DynamicResource AccentColor}" CornerRadius="6"
-                                    Width="24" Height="24">
-                                <TextBlock Text="&#xE8BD;" FontFamily="Segoe MDL2 Assets" FontSize="12"
-                                           Foreground="White" HorizontalAlignment="Center" VerticalAlignment="Center"/>
-                            </Border>
-                            <TextBlock Text="AX Agent" FontSize="14" FontWeight="Bold"
-                                       Foreground="{DynamicResource PrimaryText}"
-                                       VerticalAlignment="Center" Margin="10,0,0,0"/>
-                        </StackPanel>
-                        <Button x:Name="BtnNewChat" Style="{StaticResource GhostBtn}"
-                                HorizontalAlignment="Right" VerticalAlignment="Center"
-                                Click="BtnNewChat_Click" ToolTip="새 대화 (Ctrl+N)"
-                                WindowChrome.IsHitTestVisibleInChrome="True">
-                            <TextBlock Text="&#xE710;" FontFamily="Segoe MDL2 Assets" FontSize="14"
-                                       Foreground="{DynamicResource SecondaryText}"/>
-                        </Button>
-                    </Grid>
-
-                    <!-- 검색 -->
-                    <Border Grid.Row="1" Background="{DynamicResource HintBackground}"
-                            CornerRadius="10" Margin="12,0,12,8" Padding="10,7">
-                        <Grid>
-                            <TextBlock Text="&#xE721;" FontFamily="Segoe MDL2 Assets" FontSize="12"
-                                       Foreground="{DynamicResource SecondaryText}" VerticalAlignment="Center"/>
-                            <TextBox x:Name="SearchBox" Background="Transparent" BorderThickness="0"
-                                     Foreground="{DynamicResource PrimaryText}"
-                                     CaretBrush="{DynamicResource AccentColor}" FontSize="12"
-                                     VerticalAlignment="Center" Margin="22,0,0,0"
-                                     TextChanged="SearchBox_TextChanged"/>
-                        </Grid>
-                    </Border>
-
-                    <!-- 카테고리 드롭다운: "모든 주제 ▼" -->
-                    <Border Grid.Row="2" Margin="12,0,12,6">
-                        <Button x:Name="BtnCategoryDrop" Style="{StaticResource GhostBtn}"
-                                HorizontalAlignment="Stretch" Padding="10,6"
-                                Click="BtnCategoryDrop_Click">
-                            <Grid HorizontalAlignment="Stretch">
-                                <StackPanel Orientation="Horizontal">
-                                    <TextBlock x:Name="CategoryIcon" Text="&#xE8BD;"
-                                               FontFamily="Segoe MDL2 Assets" FontSize="12"
-                                               Foreground="{DynamicResource AccentColor}"
-                                               VerticalAlignment="Center" Margin="0,0,8,0"/>
-                                    <TextBlock x:Name="CategoryLabel" Text="모든 주제"
-                                               FontSize="12" FontWeight="SemiBold"
-                                               Foreground="{DynamicResource PrimaryText}"
-                                               VerticalAlignment="Center"/>
-                                </StackPanel>
-                                <TextBlock Text="&#xE70D;" FontFamily="Segoe MDL2 Assets" FontSize="9"
-                                           Foreground="{DynamicResource SecondaryText}"
-                                           HorizontalAlignment="Right" VerticalAlignment="Center"/>
-                            </Grid>
-                        </Button>
-                    </Border>
-
-                    <!-- 대화 목록 -->
-                    <ScrollViewer Grid.Row="3" VerticalScrollBarVisibility="Auto"
-                                  HorizontalScrollBarVisibility="Disabled">
-                        <StackPanel x:Name="ConversationPanel" Margin="6,0"/>
-                    </ScrollViewer>
-
-                    <!-- 하단: 삭제 -->
-                    <Border Grid.Row="4" BorderBrush="{DynamicResource SeparatorColor}" BorderThickness="0,1,0,0"
-                            Padding="0,4">
-                        <Button x:Name="BtnDeleteAll" Style="{StaticResource GhostBtn}"
-                                HorizontalAlignment="Center" VerticalAlignment="Center"
-                                Click="BtnDeleteAll_Click">
-                            <StackPanel Orientation="Horizontal">
-                                <TextBlock Text="&#xE74D;" FontFamily="Segoe MDL2 Assets" FontSize="11"
-                                           Foreground="#AA5555" VerticalAlignment="Center" Margin="0,0,6,0"/>
-                                <TextBlock Text="전체 삭제" FontSize="11" Foreground="#AA5555"/>
-                            </StackPanel>
-                        </Button>
-                    </Border>
-
-                    <!-- 하단: 사용자 계정 -->
-                    <Border Grid.Row="5" Margin="12,0,12,8">
-                        <Grid>
-                            <Grid.ColumnDefinitions>
-                                <ColumnDefinition Width="Auto"/>
-                                <ColumnDefinition Width="*"/>
-                            </Grid.ColumnDefinitions>
-                            <Border Grid.Column="0" Width="34" Height="34" CornerRadius="17"
-                                    Background="{DynamicResource AccentColor}" Margin="0,0,10,0">
-                                <TextBlock x:Name="UserInitialSidebar" Text="U" FontSize="14" FontWeight="Bold"
-                                           Foreground="White" HorizontalAlignment="Center" VerticalAlignment="Center"/>
-                            </Border>
-                            <StackPanel Grid.Column="1" VerticalAlignment="Center">
-                                <TextBlock x:Name="UserNameText" Text="" FontSize="12" FontWeight="SemiBold"
-                                           Foreground="{DynamicResource PrimaryText}"
-                                           TextTrimming="CharacterEllipsis"/>
-                                <TextBlock x:Name="UserPcText" Text="" FontSize="10"
-                                           Foreground="{DynamicResource SecondaryText}"/>
-                            </StackPanel>
-                        </Grid>
-                    </Border>
-                </Grid>
-            </Border>
+            <ctrl:AgentSidebarView x:Name="Sidebar" Grid.Column="1"/>
 
             <!-- ══════════════════════════════════════════════════════ -->
             <!-- 우측: 메시지 영역                                       -->
@@ -340,52 +228,10 @@
                                          KeyDown="ChatTitleEdit_KeyDown"/>
                             </Grid>
                         </StackPanel>
-                        <!-- 우: 모델 칩 + Plan 모드 + 권한 칩 + 프리뷰 토글 버튼 -->
+                        <!-- 우: AgentSessionHeaderBar (모델/Plan/권한 칩) + 미리보기 -->
                         <StackPanel Orientation="Horizontal" HorizontalAlignment="Right" VerticalAlignment="Center">
-                            <!-- Phase 17-UI-B: 모델 표시 칩 (클릭 → 모델 선택기) -->
-                            <Button x:Name="ModelHeaderChip" Style="{StaticResource OutlineHoverBtn}"
-                                    Click="BtnModelSelector_Click"
-                                    ToolTip="모델 변경" Margin="0,0,4,0" Padding="7,3">
-                                <StackPanel Orientation="Horizontal">
-                                    <TextBlock Text="&#xEA86;" FontFamily="Segoe MDL2 Assets" FontSize="10"
-                                               Foreground="{DynamicResource SecondaryText}"
-                                               VerticalAlignment="Center" Margin="0,0,4,0"/>
-                                    <TextBlock x:Name="ModelHeaderLabel" Text="" FontSize="11"
-                                               Foreground="{DynamicResource SecondaryText}"
-                                               VerticalAlignment="Center"/>
-                                </StackPanel>
-                            </Button>
-                            <!-- Plan 모드 토글 (Off/Auto/Always 3단 순환 클릭) -->
-                            <Border x:Name="BtnPlanMode" Cursor="Hand"
-                                    CornerRadius="6" Padding="6,3"
-                                    Background="#1A4B5EFC" Margin="0,0,6,0"
-                                    MouseLeftButtonUp="BtnPlanMode_Click"
-                                    ToolTip="Plan 모드: 에이전트가 실행 전 계획을 수립합니다">
-                                <StackPanel Orientation="Horizontal">
-                                    <TextBlock x:Name="PlanModeIcon" Text="&#xE9D9;" FontFamily="Segoe MDL2 Assets" FontSize="11"
-                                               Foreground="{DynamicResource AccentColor}"
-                                               VerticalAlignment="Center" Margin="0,0,4,0"/>
-                                    <TextBlock x:Name="PlanModeLabel" Text="Plan" FontSize="11" FontWeight="SemiBold"
-                                               Foreground="{DynamicResource AccentColor}"
-                                               VerticalAlignment="Center"/>
-                                    <TextBlock x:Name="PlanModeValue" Text="Off" FontSize="11"
-                                               Foreground="{DynamicResource SecondaryText}"
-                                               VerticalAlignment="Center" Margin="4,0,0,0"/>
-                                </StackPanel>
-                            </Border>
-                            <!-- Phase 17-UI-B: 권한 모드 표시 칩 (클릭 → 권한 팝업) -->
-                            <Button x:Name="PermissionHeaderChip" Style="{StaticResource OutlineHoverBtn}"
-                                    Click="PermissionHeaderChip_Click"
-                                    ToolTip="파일 접근 권한 모드 변경" Margin="0,0,6,0" Padding="7,3">
-                                <StackPanel Orientation="Horizontal">
-                                    <TextBlock Text="&#xE72E;" FontFamily="Segoe MDL2 Assets" FontSize="10"
-                                               Foreground="#4FC3F7"
-                                               VerticalAlignment="Center" Margin="0,0,4,0"/>
-                                    <TextBlock x:Name="PermissionHeaderLabel" Text="Ask" FontSize="11"
-                                               Foreground="{DynamicResource SecondaryText}"
-                                               VerticalAlignment="Center"/>
-                                </StackPanel>
-                            </Button>
+                            <!-- Phase 17-UI-C: AgentSessionHeaderBar UserControl -->
+                            <ctrl:AgentSessionHeaderBar x:Name="SessionHeaderBar" VerticalAlignment="Center"/>
                             <Button x:Name="BtnPreviewToggle" Style="{StaticResource GhostBtn}"
                                     Click="BtnPreviewToggle_Click" ToolTip="미리보기 패널" Visibility="Collapsed"
                                     Padding="8,4">
@@ -767,13 +613,18 @@
                                 BorderBrush="{DynamicResource BorderColor}" BorderThickness="1.5">
                             <Grid>
                                 <Grid.RowDefinitions>
+                                    <RowDefinition Height="Auto"/>
                                     <RowDefinition Height="Auto"/>
                                     <RowDefinition Height="Auto"/>
                                     <RowDefinition Height="*"/>
                                 </Grid.RowDefinitions>
 
-                                <!-- Row 0: 모델 셀렉터 + 템플릿 버튼 -->
-                                <Grid Grid.Row="0">
+                                <!-- Row 0: Phase 17-UI-E: @ / 스킬 / 첨부 툴바 (AgentInputArea 툴바 전용) -->
+                                <ctrl:AgentInputArea x:Name="InputToolbar" Grid.Row="0"
+                                                     IsToolbarOnly="True"/>
+
+                                <!-- Row 1: 모델 셀렉터 + 템플릿 버튼 -->
+                                <Grid Grid.Row="1">
                                     <Button x:Name="BtnModelSelector"
                                             Style="{StaticResource OutlineHoverBtn}"
                                             HorizontalAlignment="Left"
@@ -811,8 +662,8 @@
                                     </Button>
                                 </Grid>
 
-                                <!-- Row 1: 첨부 파일 목록 -->
-                                <ItemsControl x:Name="AttachedFilesPanel" Grid.Row="1"
+                                <!-- Row 2: 첨부 파일 목록 -->
+                                <ItemsControl x:Name="AttachedFilesPanel" Grid.Row="2"
                                               Margin="8,0,8,2" Visibility="Collapsed">
                                     <ItemsControl.ItemsPanel>
                                         <ItemsPanelTemplate>
@@ -821,8 +672,8 @@
                                     </ItemsControl.ItemsPanel>
                                 </ItemsControl>
 
-                                <!-- 입력 영역 (Row 2) -->
-                                <Grid Grid.Row="2">
+                                <!-- 입력 영역 (Row 3) -->
+                                <Grid Grid.Row="3">
                                     <Grid.ColumnDefinitions>
                                         <ColumnDefinition Width="*"/>
                                         <ColumnDefinition Width="Auto"/>
diff --git a/src/AxCopilot/Views/ChatWindow.xaml.cs b/src/AxCopilot/Views/ChatWindow.xaml.cs
index e5c37d1..c67131c 100644
--- a/src/AxCopilot/Views/ChatWindow.xaml.cs
+++ b/src/AxCopilot/Views/ChatWindow.xaml.cs
@@ -127,7 +127,10 @@ public partial class ChatWindow : Window
             UpdateAnalyzerButtonVisibility();
             UpdateModelLabel();
             UpdatePlanModeUI();
-            UpdatePermissionUI(); // Phase 17-UI-B: 헤더 권한 칩 초기화
+            InitSessionHeaderBar();              // Phase 17-UI-C: 이벤트 연결
+            InitSidebarEvents();                 // Phase 17-UI-D: 사이드바 이벤트 연결
+            InitInputToolbar();                  // Phase 17-UI-E: 입력 툴바 이벤트 연결
+            UpdatePermissionUI();                // Phase 17-UI-C: 헤더 권한 칩 초기화
             InputBox.Focus();
             MessageScroll.ScrollChanged += MessageScroll_ScrollChanged;
 
diff --git a/src/AxCopilot/Views/Controls/AgentInputArea.xaml b/src/AxCopilot/Views/Controls/AgentInputArea.xaml
index f245efc..18cc862 100644
--- a/src/AxCopilot/Views/Controls/AgentInputArea.xaml
+++ b/src/AxCopilot/Views/Controls/AgentInputArea.xaml
@@ -2,10 +2,12 @@
              xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
              xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
 
-    <!-- Phase 32-D: 멀티기능 입력 영역 (Claude.ai + Codex 스타일)
-         상단 툴바 (@멘션/스킬/첨부) + 텍스트 입력 + 하단 칩/전송 -->
+    <!-- Phase 17-UI-E: 멀티기능 입력 영역 (Claude.ai + Codex 스타일)
+         IsToolbarOnly=True 시 Row 0 (@ / 스킬 / 첨부)만 표시.
+         ChatWindow에서는 툴바 행만 사용하여 기존 InputBox 위에 배치. -->
 
-    <Border Background="{DynamicResource LauncherBackground}"
+    <Border x:Name="OuterBorder"
+            Background="{DynamicResource LauncherBackground}"
             BorderBrush="{DynamicResource BorderColor}" BorderThickness="0,1,0,0"
             Padding="16,8">
         <Grid>
@@ -15,7 +17,7 @@
                 <RowDefinition Height="Auto"/>
             </Grid.RowDefinitions>
 
-            <!-- Row 0: 상단 툴바 — @ / 스킬 / 첨부 -->
+            <!-- Row 0: 상단 툴바 — @ / 스킬 / 첨부 (IsToolbarOnly=True에서도 표시) -->
             <StackPanel Grid.Row="0" Orientation="Horizontal" Margin="0,0,0,6">
                 <!-- @ 멘션 -->
                 <Border CornerRadius="4" Padding="6,3" Margin="0,0,6,0" Cursor="Hand"
@@ -74,8 +76,9 @@
                 <StackPanel x:Name="AttachmentChips" Orientation="Horizontal" Margin="8,0,0,0"/>
             </StackPanel>
 
-            <!-- Row 1: 텍스트 입력 -->
-            <Border Grid.Row="1" Background="{DynamicResource ItemBackground}"
+            <!-- Row 1: 텍스트 입력 (IsToolbarOnly=True 시 Collapsed) -->
+            <Border x:Name="InputTextBoxRow" Grid.Row="1"
+                    Background="{DynamicResource ItemBackground}"
                     CornerRadius="12" Padding="12,8" Margin="0,0,0,6">
                 <TextBox x:Name="InputBox" FontSize="13" AcceptsReturn="True"
                          TextWrapping="Wrap" MinHeight="40" MaxHeight="200"
@@ -87,8 +90,8 @@
                 </TextBox>
             </Border>
 
-            <!-- Row 2: 하단 칩 + 전송 버튼 -->
-            <Grid Grid.Row="2">
+            <!-- Row 2: 하단 칩 + 전송 버튼 (IsToolbarOnly=True 시 Collapsed) -->
+            <Grid x:Name="ChipsSendRow" Grid.Row="2">
                 <StackPanel Orientation="Horizontal" VerticalAlignment="Center">
                     <!-- 모델명 칩 -->
                     <Border CornerRadius="10" Padding="8,3" Margin="0,0,6,0"
diff --git a/src/AxCopilot/Views/Controls/AgentInputArea.xaml.cs b/src/AxCopilot/Views/Controls/AgentInputArea.xaml.cs
index 34de874..8f4e110 100644
--- a/src/AxCopilot/Views/Controls/AgentInputArea.xaml.cs
+++ b/src/AxCopilot/Views/Controls/AgentInputArea.xaml.cs
@@ -5,13 +5,56 @@ using System.Windows.Input;
 namespace AxCopilot.Views.Controls;
 
 /// <summary>
-/// Phase 32-D: 멀티기능 입력 영역.
+/// Phase 17-UI-E: 멀티기능 입력 영역.
 /// @ 멘션, / 스킬, 첨부, Ctrl+Enter 전송, 모델/권한/Plan 칩 표시.
+/// IsToolbarOnly=True 시 상단 툴바 행(@/스킬/첨부)만 표시하고
+/// TextBox 행과 칩/전송 행은 숨깁니다 (ChatWindow 기존 InputBox 위에 배치용).
 /// </summary>
 public partial class AgentInputArea : UserControl
 {
     private bool _isStreaming;
 
+    // ── IsToolbarOnly 의존성 프로퍼티 ─────────────────────────────────────
+
+    public static readonly DependencyProperty IsToolbarOnlyProperty =
+        DependencyProperty.Register(
+            nameof(IsToolbarOnly),
+            typeof(bool),
+            typeof(AgentInputArea),
+            new PropertyMetadata(false, OnIsToolbarOnlyChanged));
+
+    /// <summary>True이면 @/스킬/첨부 툴바 행만 표시합니다.</summary>
+    public bool IsToolbarOnly
+    {
+        get => (bool)GetValue(IsToolbarOnlyProperty);
+        set => SetValue(IsToolbarOnlyProperty, value);
+    }
+
+    private static void OnIsToolbarOnlyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
+    {
+        if (d is AgentInputArea ctrl)
+            ctrl.ApplyToolbarOnlyMode((bool)e.NewValue);
+    }
+
+    private void ApplyToolbarOnlyMode(bool toolbarOnly)
+    {
+        var vis = toolbarOnly ? Visibility.Collapsed : Visibility.Visible;
+        if (InputTextBoxRow != null)  InputTextBoxRow.Visibility = vis;
+        if (ChipsSendRow != null)     ChipsSendRow.Visibility    = vis;
+        // 툴바 전용 모드에서는 외부 Border 배경/테두리를 투명하게 처리
+        if (OuterBorder != null)
+        {
+            OuterBorder.BorderThickness = toolbarOnly ? new Thickness(0) : new Thickness(0, 1, 0, 0);
+            OuterBorder.Padding         = toolbarOnly ? new Thickness(8, 0, 8, 0) : new Thickness(16, 8, 16, 8);
+            OuterBorder.Background      = toolbarOnly
+                ? System.Windows.Media.Brushes.Transparent
+                : TryFindResource("LauncherBackground") as System.Windows.Media.Brush
+                    ?? System.Windows.Media.Brushes.Transparent;
+        }
+    }
+
+    // ── 이벤트 ────────────────────────────────────────────────────────────
+
     /// <summary>메시지 전송 이벤트. 인자: 입력 텍스트.</summary>
     public event EventHandler<string>? MessageSent;
 
@@ -27,6 +70,8 @@ public partial class AgentInputArea : UserControl
     /// <summary>첨부 클릭 이벤트.</summary>
     public event EventHandler? AttachRequested;
 
+    // ── 공개 API ──────────────────────────────────────────────────────────
+
     /// <summary>입력 텍스트.</summary>
     public string Text
     {
@@ -48,6 +93,11 @@ public partial class AgentInputArea : UserControl
     public AgentInputArea()
     {
         InitializeComponent();
+        // Loaded 후 IsToolbarOnly 초기 적용 (XAML 설정값 반영)
+        Loaded += (_, _) =>
+        {
+            if (IsToolbarOnly) ApplyToolbarOnlyMode(true);
+        };
     }
 
     /// <summary>하단 칩 텍스트를 업데이트합니다.</summary>
@@ -105,7 +155,7 @@ public partial class AgentInputArea : UserControl
     /// <summary>입력 포커스를 설정합니다.</summary>
     public void FocusInput() => InputBox.Focus();
 
-    #region ── 이벤트 핸들러 ──
+    // ── 이벤트 핸들러 ────────────────────────────────────────────────────
 
     private void InputBox_KeyDown(object sender, KeyEventArgs e)
     {
@@ -139,7 +189,7 @@ public partial class AgentInputArea : UserControl
     private void BtnAttach_Click(object sender, MouseButtonEventArgs e)
         => AttachRequested?.Invoke(this, EventArgs.Empty);
 
-    #endregion
+    // ── 내부 헬퍼 ────────────────────────────────────────────────────────
 
     private void TrySend()
     {
diff --git a/src/AxCopilot/Views/Controls/AgentSessionHeaderBar.xaml b/src/AxCopilot/Views/Controls/AgentSessionHeaderBar.xaml
index 1b459de..a2686e8 100644
--- a/src/AxCopilot/Views/Controls/AgentSessionHeaderBar.xaml
+++ b/src/AxCopilot/Views/Controls/AgentSessionHeaderBar.xaml
@@ -1,26 +1,25 @@
 <UserControl x:Class="AxCopilot.Views.Controls.AgentSessionHeaderBar"
              xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
              xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-             Height="42">
+             Height="38">
 
-    <!-- Phase 32-C: 세션 헤더 바 (Codex 스타일)
-         모델/Plan/권한 칩 + 도구 아이콘 + 설정 버튼 -->
+    <!-- Phase 17-UI-C: 세션 헤더 바 — ChatWindow Row 1 에 임베드.
+         배경/테두리는 부모(Row 1 Border)가 담당하므로 이 컨트롤은 투명. -->
 
-    <Border Background="{DynamicResource LauncherBackground}"
-            BorderBrush="{DynamicResource BorderColor}" BorderThickness="0,0,0,1">
-        <Grid Margin="16,0">
+    <Border Background="Transparent" BorderThickness="0">
+        <Grid Margin="4,0">
 
-            <!-- 좌측: 현재 탭 레이블 -->
+            <!-- 좌측: 현재 탭 레이블 (탭 이름 또는 대화 제목) -->
             <StackPanel Orientation="Horizontal" HorizontalAlignment="Left" VerticalAlignment="Center">
-                <TextBlock x:Name="TxtTabLabel" Text="Chat" FontSize="14" FontWeight="SemiBold"
-                           Foreground="{DynamicResource PrimaryText}"/>
+                <TextBlock x:Name="TxtTabLabel" Text="Chat" FontSize="11" FontWeight="SemiBold"
+                           Foreground="{DynamicResource SecondaryText}" Margin="4,0,8,0"/>
             </StackPanel>
 
             <!-- 중앙: 모델/Plan/권한 칩 -->
             <StackPanel Orientation="Horizontal" HorizontalAlignment="Center" VerticalAlignment="Center">
 
                 <!-- 모델 칩 -->
-                <Border x:Name="ChipModel" CornerRadius="12" Padding="10,4" Margin="4,0"
+                <Border x:Name="ChipModel" CornerRadius="10" Padding="8,3" Margin="3,0"
                         Cursor="Hand" MouseLeftButtonUp="ChipModel_Click">
                     <Border.Style>
                         <Style TargetType="Border">
@@ -33,9 +32,9 @@
                         </Style>
                     </Border.Style>
                     <StackPanel Orientation="Horizontal">
-                        <TextBlock Text="&#xE964;" FontFamily="Segoe MDL2 Assets" FontSize="10"
+                        <TextBlock Text="&#xEA86;" FontFamily="Segoe MDL2 Assets" FontSize="10"
                                    Foreground="{DynamicResource AccentColor}" VerticalAlignment="Center"/>
-                        <TextBlock x:Name="TxtModelChip" Text="llama3" FontSize="11" Margin="4,0"
+                        <TextBlock x:Name="TxtModelChip" Text="llama3" FontSize="11" Margin="4,0,2,0"
                                    Foreground="{DynamicResource PrimaryText}"/>
                         <TextBlock Text="&#xE70D;" FontFamily="Segoe MDL2 Assets" FontSize="8"
                                    Foreground="{DynamicResource SecondaryText}" VerticalAlignment="Center"/>
@@ -43,7 +42,7 @@
                 </Border>
 
                 <!-- Plan 모드 칩 (3-state: Off/Auto/Always) -->
-                <Border x:Name="ChipPlan" CornerRadius="12" Padding="10,4" Margin="4,0"
+                <Border x:Name="ChipPlan" CornerRadius="10" Padding="8,3" Margin="3,0"
                         Cursor="Hand" MouseLeftButtonUp="ChipPlan_Click">
                     <Border.Style>
                         <Style TargetType="Border">
@@ -56,15 +55,15 @@
                         </Style>
                     </Border.Style>
                     <StackPanel Orientation="Horizontal">
-                        <TextBlock Text="&#xE8FD;" FontFamily="Segoe MDL2 Assets" FontSize="10"
+                        <TextBlock x:Name="PlanIcon" Text="&#xE9D9;" FontFamily="Segoe MDL2 Assets" FontSize="10"
                                    Foreground="{DynamicResource SecondaryText}" VerticalAlignment="Center"/>
-                        <TextBlock x:Name="TxtPlanChip" Text="Plan: Off" FontSize="11" Margin="4,0"
+                        <TextBlock x:Name="TxtPlanChip" Text="Plan: Off" FontSize="11" Margin="4,0,0,0"
                                    Foreground="{DynamicResource PrimaryText}"/>
                     </StackPanel>
                 </Border>
 
                 <!-- 권한 모드 칩 -->
-                <Border x:Name="ChipPermission" CornerRadius="12" Padding="10,4" Margin="4,0"
+                <Border x:Name="ChipPermission" CornerRadius="10" Padding="8,3" Margin="3,0"
                         Cursor="Hand" MouseLeftButtonUp="ChipPermission_Click">
                     <Border.Style>
                         <Style TargetType="Border">
@@ -77,18 +76,19 @@
                         </Style>
                     </Border.Style>
                     <StackPanel Orientation="Horizontal">
-                        <TextBlock Text="&#xE72E;" FontFamily="Segoe MDL2 Assets" FontSize="10"
+                        <TextBlock x:Name="PermIcon" Text="&#xE72E;" FontFamily="Segoe MDL2 Assets" FontSize="10"
                                    Foreground="#4FC3F7" VerticalAlignment="Center"/>
-                        <TextBlock x:Name="TxtPermissionChip" Text="Ask" FontSize="11" Margin="4,0"
+                        <TextBlock x:Name="TxtPermissionChip" Text="Ask" FontSize="11" Margin="4,0,0,0"
                                    Foreground="{DynamicResource PrimaryText}"/>
                     </StackPanel>
                 </Border>
             </StackPanel>
 
-            <!-- 우측: 설정 버튼 -->
+            <!-- 우측: 설정 패널 토글 버튼 -->
             <StackPanel Orientation="Horizontal" HorizontalAlignment="Right" VerticalAlignment="Center">
-                <Border CornerRadius="4" Padding="8,4" Cursor="Hand" Margin="4,0"
-                        MouseLeftButtonUp="BtnSettings_Click">
+                <Border CornerRadius="6" Padding="6,3" Cursor="Hand" Margin="0,0,4,0"
+                        MouseLeftButtonUp="BtnSettings_Click"
+                        ToolTip="에이전트 설정 패널">
                     <Border.Style>
                         <Style TargetType="Border">
                             <Setter Property="Background" Value="Transparent"/>
@@ -99,7 +99,7 @@
                             </Style.Triggers>
                         </Style>
                     </Border.Style>
-                    <TextBlock Text="&#xE713;" FontFamily="Segoe MDL2 Assets" FontSize="14"
+                    <TextBlock Text="&#xE713;" FontFamily="Segoe MDL2 Assets" FontSize="13"
                                Foreground="{DynamicResource SecondaryText}"/>
                 </Border>
             </StackPanel>
diff --git a/src/AxCopilot/Views/Controls/AgentSessionHeaderBar.xaml.cs b/src/AxCopilot/Views/Controls/AgentSessionHeaderBar.xaml.cs
index a36fce2..738091c 100644
--- a/src/AxCopilot/Views/Controls/AgentSessionHeaderBar.xaml.cs
+++ b/src/AxCopilot/Views/Controls/AgentSessionHeaderBar.xaml.cs
@@ -5,24 +5,25 @@ using System.Windows.Media;
 namespace AxCopilot.Views.Controls;
 
 /// <summary>
-/// Phase 32-C: 세션 헤더 바 (Codex 스타일).
-/// 모델/Plan/권한 칩을 인라인 표시하고, 클릭 시 빠른 전환.
+/// Phase 17-UI-C: 세션 헤더 바 (Codex 스타일).
+/// ChatWindow Row 1 서브바에 임베드되어 모델/Plan/권한 칩을 표시.
+/// 배경/테두리는 부모 컨테이너에서 제공하므로 이 컨트롤은 투명.
 /// </summary>
 public partial class AgentSessionHeaderBar : UserControl
 {
-    private string _planMode = "off"; // off → auto → always
-    private string _permissionMode = "Ask"; // Ask → Auto → Deny → Bypass
+    private string _planMode = "off"; // off / auto / always
+    private string _permissionMode = "Ask"; // Ask / Auto / Deny
 
-    /// <summary>모델 선택 클릭 이벤트.</summary>
+    /// <summary>모델 칩 클릭 이벤트 — 부모 창에서 모델 선택 팝업 열기.</summary>
     public event EventHandler? ModelChipClicked;
 
     /// <summary>Plan 모드 변경 이벤트. 인자: 새 모드 ("off"/"auto"/"always").</summary>
     public event EventHandler<string>? PlanModeChanged;
 
-    /// <summary>권한 모드 변경 이벤트. 인자: 새 모드.</summary>
+    /// <summary>권한 모드 변경 이벤트. 인자: 새 모드 ("Ask"/"Auto"/"Deny").</summary>
     public event EventHandler<string>? PermissionModeChanged;
 
-    /// <summary>설정 패널 토글 요청.</summary>
+    /// <summary>설정 패널 토글 요청 이벤트.</summary>
     public event EventHandler? SettingsRequested;
 
     public AgentSessionHeaderBar()
@@ -30,46 +31,64 @@ public partial class AgentSessionHeaderBar : UserControl
         InitializeComponent();
     }
 
-    /// <summary>탭 레이블을 업데이트합니다.</summary>
+    // ─── 외부에서 상태 주입 ───────────────────────────────────────────────
+
+    /// <summary>탭 레이블(좌측)을 업데이트합니다.</summary>
     public void SetTabLabel(string tab) => TxtTabLabel.Text = tab;
 
-    /// <summary>모델명 칩을 업데이트합니다.</summary>
+    /// <summary>모델 칩 텍스트를 업데이트합니다. 30자 초과 시 축약.</summary>
     public void SetModel(string modelName)
     {
-        // 긴 모델명은 축약
-        var display = modelName.Length > 20 ? modelName[..20] + "…" : modelName;
-        TxtModelChip.Text = display;
+        TxtModelChip.Text = modelName.Length > 30 ? modelName[..30] + "…" : modelName;
     }
 
-    /// <summary>Plan 모드를 설정합니다.</summary>
+    /// <summary>Plan 모드 칩을 업데이트합니다. 모드: "off" / "auto" / "always".</summary>
     public void SetPlanMode(string mode)
     {
         _planMode = mode;
         TxtPlanChip.Text = mode switch
         {
-            "auto" => "Plan: Auto",
+            "auto"   => "Plan: Auto",
             "always" => "Plan: Always",
-            _ => "Plan: Off",
+            _        => "Plan: Off",
         };
 
-        // 활성 상태 색상
-        var icon = ChipPlan.Child is StackPanel sp && sp.Children[0] is System.Windows.Controls.TextBlock tb ? tb : null;
-        if (icon != null)
+        // 활성 상태 색상 — PlanIcon x:Name 직접 참조
+        if (PlanIcon != null)
         {
-            icon.Foreground = mode != "off"
+            PlanIcon.Foreground = mode != "off"
                 ? (TryFindResource("AccentColor") as Brush ?? Brushes.DodgerBlue)
                 : (TryFindResource("SecondaryText") as Brush ?? Brushes.Gray);
         }
+
+        // Plan 활성 시 칩 배경 강조
+        if (ChipPlan != null)
+        {
+            ChipPlan.Background = mode != "off"
+                ? new SolidColorBrush(Color.FromArgb(0x1A, 0x4B, 0x5E, 0xFC))
+                : (TryFindResource("ItemBackground") as Brush ?? Brushes.Transparent);
+        }
     }
 
-    /// <summary>권한 모드를 설정합니다.</summary>
+    /// <summary>권한 모드 칩을 업데이트합니다. 모드: "Ask" / "Auto" / "Deny".</summary>
     public void SetPermissionMode(string mode)
     {
         _permissionMode = mode;
         TxtPermissionChip.Text = mode;
+
+        // 권한 모드별 아이콘 색상
+        if (PermIcon != null)
+        {
+            PermIcon.Foreground = mode switch
+            {
+                "Auto" => new SolidColorBrush(Color.FromRgb(0xDD, 0x6B, 0x20)),
+                "Deny" => new SolidColorBrush(Color.FromRgb(0xC5, 0x0F, 0x1F)),
+                _      => new SolidColorBrush(Color.FromRgb(0x4F, 0xC3, 0xF7)), // Ask = 하늘색
+            };
+        }
     }
 
-    #region ── 이벤트 핸들러 ──
+    // ─── 이벤트 핸들러 ───────────────────────────────────────────────────
 
     private void ChipModel_Click(object sender, System.Windows.Input.MouseButtonEventArgs e)
         => ModelChipClicked?.Invoke(this, EventArgs.Empty);
@@ -79,30 +98,18 @@ public partial class AgentSessionHeaderBar : UserControl
         // 3-state 순환: off → auto → always → off
         _planMode = _planMode switch
         {
-            "off" => "auto",
+            "off"  => "auto",
             "auto" => "always",
-            _ => "off",
+            _      => "off",
         };
         SetPlanMode(_planMode);
         PlanModeChanged?.Invoke(this, _planMode);
     }
 
     private void ChipPermission_Click(object sender, System.Windows.Input.MouseButtonEventArgs e)
-    {
-        // 4-state 순환: Ask → Auto → Deny → Bypass → Ask
-        _permissionMode = _permissionMode switch
-        {
-            "Ask" => "Auto",
-            "Auto" => "Deny",
-            "Deny" => "Bypass",
-            _ => "Ask",
-        };
-        SetPermissionMode(_permissionMode);
-        PermissionModeChanged?.Invoke(this, _permissionMode);
-    }
+        // 권한 칩 클릭 → 팝업은 부모(ChatWindow)가 처리
+        => PermissionModeChanged?.Invoke(this, _permissionMode);
 
     private void BtnSettings_Click(object sender, System.Windows.Input.MouseButtonEventArgs e)
         => SettingsRequested?.Invoke(this, EventArgs.Empty);
-
-    #endregion
 }
diff --git a/src/AxCopilot/Views/Controls/AgentSidebarView.xaml b/src/AxCopilot/Views/Controls/AgentSidebarView.xaml
index b1488c7..3052889 100644
--- a/src/AxCopilot/Views/Controls/AgentSidebarView.xaml
+++ b/src/AxCopilot/Views/Controls/AgentSidebarView.xaml
@@ -1,52 +1,50 @@
 <UserControl x:Class="AxCopilot.Views.Controls.AgentSidebarView"
              xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
              xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-             MinWidth="48" Width="260">
+             Width="270">
 
-    <!-- Phase 32-B: 좌측 사이드바 (Claude.ai 스타일)
-         탭 세그먼트 + 프리셋 + 대화 이력 + 새 대화 -->
+    <!-- Phase 17-UI-D: 좌측 사이드바 UserControl
+         기존 SidebarPanel Grid를 대체. ChatWindow 프록시 패턴으로 기존 코드와 호환.
+         탭 세그먼트(Chat/Cowork/Code) + 카테고리 필터 + 대화 목록 + 사용자 계정. -->
 
-    <Border Background="{DynamicResource LauncherBackground}"
+    <Border Background="{DynamicResource ItemBackground}"
             BorderBrush="{DynamicResource BorderColor}"
             BorderThickness="0,0,1,0">
         <Grid>
             <Grid.RowDefinitions>
-                <RowDefinition Height="54"/>
-                <RowDefinition Height="Auto"/>
-                <RowDefinition Height="Auto"/>
-                <RowDefinition Height="Auto"/>
-                <RowDefinition Height="*"/>
-                <RowDefinition Height="Auto"/>
-                <RowDefinition Height="48"/>
+                <RowDefinition Height="54"/>   <!-- 0: 헤더 (로고 + 새 대화) -->
+                <RowDefinition Height="Auto"/> <!-- 1: 탭 세그먼트 (Chat/Cowork/Code) -->
+                <RowDefinition Height="Auto"/> <!-- 2: 검색 -->
+                <RowDefinition Height="Auto"/> <!-- 3: 카테고리 드롭다운 -->
+                <RowDefinition Height="*"/>    <!-- 4: 대화 목록 -->
+                <RowDefinition Height="Auto"/> <!-- 5: 하단 삭제 버튼 -->
+                <RowDefinition Height="52"/>   <!-- 6: 사용자 계정 -->
             </Grid.RowDefinitions>
 
-            <!-- Row 0: 헤더 — 로고 + 접기 버튼 -->
-            <Grid Grid.Row="0" Margin="12,0">
+            <!-- Row 0: 헤더 — 로고 + 새 대화 버튼 -->
+            <Grid Grid.Row="0" Margin="16,0">
                 <StackPanel Orientation="Horizontal" VerticalAlignment="Center">
-                    <TextBlock Text="&#xE7F8;" FontFamily="Segoe MDL2 Assets" FontSize="18"
-                               Foreground="{DynamicResource AccentColor}" VerticalAlignment="Center"/>
-                    <TextBlock x:Name="TxtTitle" Text=" AX Agent" FontSize="15" FontWeight="SemiBold"
-                               Foreground="{DynamicResource PrimaryText}" Margin="6,0,0,0" VerticalAlignment="Center"/>
+                    <Border Background="{DynamicResource AccentColor}" CornerRadius="6"
+                            Width="24" Height="24">
+                        <TextBlock Text="&#xE8BD;" FontFamily="Segoe MDL2 Assets" FontSize="12"
+                                   Foreground="White" HorizontalAlignment="Center" VerticalAlignment="Center"/>
+                    </Border>
+                    <TextBlock Text="AX Agent" FontSize="14" FontWeight="Bold"
+                               Foreground="{DynamicResource PrimaryText}"
+                               VerticalAlignment="Center" Margin="10,0,0,0"/>
                 </StackPanel>
-                <Border HorizontalAlignment="Right" VerticalAlignment="Center"
-                        Background="Transparent" Cursor="Hand" Padding="8,6" CornerRadius="4"
-                        MouseLeftButtonUp="BtnCollapse_Click">
-                    <Border.Style>
-                        <Style TargetType="Border">
-                            <Style.Triggers>
-                                <Trigger Property="IsMouseOver" Value="True">
-                                    <Setter Property="Background" Value="#18FFFFFF"/>
-                                </Trigger>
-                            </Style.Triggers>
-                        </Style>
-                    </Border.Style>
-                    <TextBlock x:Name="IconCollapse" Text="&#xE76B;" FontFamily="Segoe MDL2 Assets"
-                               FontSize="12" Foreground="{DynamicResource SecondaryText}"/>
-                </Border>
+                <Button x:Name="BtnNewChat" Style="{DynamicResource GhostBtn}"
+                        HorizontalAlignment="Right" VerticalAlignment="Center"
+                        Click="BtnNewChat_Click" ToolTip="새 대화 (Ctrl+N)"
+                        WindowChrome.IsHitTestVisibleInChrome="True">
+                    <TextBlock Text="&#xE710;" FontFamily="Segoe MDL2 Assets" FontSize="14"
+                               Foreground="{DynamicResource SecondaryText}"/>
+                </Button>
             </Grid>
 
-            <!-- Row 1: 탭 세그먼트 (Chat | Cowork | Code) -->
-            <Border Grid.Row="1" Margin="12,0,12,8" Background="{DynamicResource ItemBackground}"
+            <!-- Row 1: 탭 세그먼트 (Chat | Cowork | Code) — Claude.ai 인라인 탭 -->
+            <Border Grid.Row="1" Margin="12,0,12,8"
+                    Background="{DynamicResource HintBackground}"
                     CornerRadius="8" Padding="3">
                 <Grid>
                     <Grid.ColumnDefinitions>
@@ -54,21 +52,20 @@
                         <ColumnDefinition Width="*"/>
                         <ColumnDefinition Width="*"/>
                     </Grid.ColumnDefinitions>
-
-                    <Border x:Name="TabChat" Grid.Column="0" CornerRadius="6" Padding="0,7"
-                            Cursor="Hand" MouseLeftButtonUp="TabChat_Click">
+                    <Border x:Name="SidebarTabChat" Grid.Column="0" CornerRadius="6" Padding="0,6"
+                            Cursor="Hand" MouseLeftButtonUp="SidebarTabChat_Click">
                         <TextBlock Text="Chat" FontSize="12" FontWeight="Medium"
                                    HorizontalAlignment="Center"
                                    Foreground="{DynamicResource PrimaryText}"/>
                     </Border>
-                    <Border x:Name="TabCowork" Grid.Column="1" CornerRadius="6" Padding="0,7"
-                            Cursor="Hand" MouseLeftButtonUp="TabCowork_Click">
+                    <Border x:Name="SidebarTabCowork" Grid.Column="1" CornerRadius="6" Padding="0,6"
+                            Cursor="Hand" MouseLeftButtonUp="SidebarTabCowork_Click">
                         <TextBlock Text="Cowork" FontSize="12" FontWeight="Medium"
                                    HorizontalAlignment="Center"
                                    Foreground="{DynamicResource PrimaryText}"/>
                     </Border>
-                    <Border x:Name="TabCode" Grid.Column="2" CornerRadius="6" Padding="0,7"
-                            Cursor="Hand" MouseLeftButtonUp="TabCode_Click">
+                    <Border x:Name="SidebarTabCode" Grid.Column="2" CornerRadius="6" Padding="0,6"
+                            Cursor="Hand" MouseLeftButtonUp="SidebarTabCode_Click">
                         <TextBlock Text="Code" FontSize="12" FontWeight="Medium"
                                    HorizontalAlignment="Center"
                                    Foreground="{DynamicResource PrimaryText}"/>
@@ -76,98 +73,91 @@
                 </Grid>
             </Border>
 
-            <!-- Row 2: 새 대화 버튼 -->
-            <Border Grid.Row="2" Margin="12,0,12,8" CornerRadius="8" Padding="0,9"
-                    Cursor="Hand" MouseLeftButtonUp="BtnNewChat_Click">
-                <Border.Style>
-                    <Style TargetType="Border">
-                        <Setter Property="Background" Value="Transparent"/>
-                        <Setter Property="BorderBrush" Value="{DynamicResource BorderColor}"/>
-                        <Setter Property="BorderThickness" Value="1"/>
-                        <Style.Triggers>
-                            <Trigger Property="IsMouseOver" Value="True">
-                                <Setter Property="Background" Value="{DynamicResource ItemHoverBackground}"/>
-                            </Trigger>
-                        </Style.Triggers>
-                    </Style>
-                </Border.Style>
-                <StackPanel Orientation="Horizontal" HorizontalAlignment="Center">
-                    <TextBlock Text="&#xE710;" FontFamily="Segoe MDL2 Assets" FontSize="12"
-                               Foreground="{DynamicResource AccentColor}" VerticalAlignment="Center"/>
-                    <TextBlock Text=" 새 대화" FontSize="12" FontWeight="Medium"
-                               Foreground="{DynamicResource PrimaryText}" Margin="4,0,0,0"/>
-                </StackPanel>
-            </Border>
-
-            <!-- Row 3: 검색 -->
-            <Border Grid.Row="3" Margin="12,0,12,8" Background="{DynamicResource ItemBackground}"
-                    CornerRadius="6" Padding="10,6">
+            <!-- Row 2: 검색 -->
+            <Border Grid.Row="2" Background="{DynamicResource HintBackground}"
+                    CornerRadius="10" Margin="12,0,12,8" Padding="10,7">
                 <Grid>
                     <TextBlock Text="&#xE721;" FontFamily="Segoe MDL2 Assets" FontSize="12"
                                Foreground="{DynamicResource SecondaryText}" VerticalAlignment="Center"/>
-                    <TextBox x:Name="TxtSearch" Margin="22,0,0,0" FontSize="12" Background="Transparent"
-                             Foreground="{DynamicResource PrimaryText}" BorderThickness="0"
-                             TextChanged="TxtSearch_TextChanged">
-                        <TextBox.Style>
-                            <Style TargetType="TextBox">
-                                <Style.Triggers>
-                                    <Trigger Property="Text" Value="">
-                                        <Setter Property="Tag" Value="대화 검색..."/>
-                                    </Trigger>
-                                </Style.Triggers>
-                            </Style>
-                        </TextBox.Style>
-                    </TextBox>
+                    <TextBox x:Name="SearchBox" Background="Transparent" BorderThickness="0"
+                             Foreground="{DynamicResource PrimaryText}"
+                             CaretBrush="{DynamicResource AccentColor}" FontSize="12"
+                             VerticalAlignment="Center" Margin="22,0,0,0"
+                             TextChanged="SearchBox_TextChanged"/>
                 </Grid>
             </Border>
 
-            <!-- Row 4: 대화 이력 목록 -->
-            <ScrollViewer Grid.Row="4" VerticalScrollBarVisibility="Auto"
-                          HorizontalScrollBarVisibility="Disabled">
-                <StackPanel x:Name="ConversationList" Margin="8,0">
-                    <!-- 코드비하인드에서 날짜 그룹별로 동적 생성 -->
-                </StackPanel>
-            </ScrollViewer>
-
-            <!-- Row 5: 삭제 전체 -->
-            <Border Grid.Row="5" Margin="12,4,12,4" Padding="0,6" Cursor="Hand"
-                    CornerRadius="6" MouseLeftButtonUp="BtnDeleteAll_Click">
-                <Border.Style>
-                    <Style TargetType="Border">
-                        <Setter Property="Background" Value="Transparent"/>
-                        <Style.Triggers>
-                            <Trigger Property="IsMouseOver" Value="True">
-                                <Setter Property="Background" Value="#18FFFFFF"/>
-                            </Trigger>
-                        </Style.Triggers>
-                    </Style>
-                </Border.Style>
-                <StackPanel Orientation="Horizontal" HorizontalAlignment="Center">
-                    <TextBlock Text="&#xE74D;" FontFamily="Segoe MDL2 Assets" FontSize="11"
-                               Foreground="#E57373" VerticalAlignment="Center"/>
-                    <TextBlock Text=" 모두 삭제" FontSize="11" Foreground="#E57373" Margin="4,0,0,0"/>
-                </StackPanel>
+            <!-- Row 3: 카테고리 드롭다운 -->
+            <Border Grid.Row="3" Margin="12,0,12,6">
+                <Border x:Name="BtnCategoryDrop" Cursor="Hand" Padding="10,6"
+                        CornerRadius="8" MouseLeftButtonUp="BtnCategoryDrop_Click">
+                    <Border.Style>
+                        <Style TargetType="Border">
+                            <Setter Property="Background" Value="Transparent"/>
+                            <Style.Triggers>
+                                <Trigger Property="IsMouseOver" Value="True">
+                                    <Setter Property="Background" Value="{DynamicResource ItemHoverBackground}"/>
+                                </Trigger>
+                            </Style.Triggers>
+                        </Style>
+                    </Border.Style>
+                    <Grid>
+                        <StackPanel Orientation="Horizontal">
+                            <TextBlock x:Name="CategoryIcon" Text="&#xE8BD;"
+                                       FontFamily="Segoe MDL2 Assets" FontSize="12"
+                                       Foreground="{DynamicResource AccentColor}"
+                                       VerticalAlignment="Center" Margin="0,0,8,0"/>
+                            <TextBlock x:Name="CategoryLabel" Text="모든 주제"
+                                       FontSize="12" FontWeight="SemiBold"
+                                       Foreground="{DynamicResource PrimaryText}"
+                                       VerticalAlignment="Center"/>
+                        </StackPanel>
+                        <TextBlock Text="&#xE70D;" FontFamily="Segoe MDL2 Assets" FontSize="9"
+                                   Foreground="{DynamicResource SecondaryText}"
+                                   HorizontalAlignment="Right" VerticalAlignment="Center"/>
+                    </Grid>
+                </Border>
             </Border>
 
-            <!-- Row 6: 하단 설정 아이콘 -->
-            <Border Grid.Row="6" BorderBrush="{DynamicResource BorderColor}" BorderThickness="0,1,0,0">
-                <Grid Margin="12,0">
-                    <Border HorizontalAlignment="Left" VerticalAlignment="Center"
-                            Cursor="Hand" Padding="8,6" CornerRadius="4"
-                            MouseLeftButtonUp="BtnSettings_Click">
-                        <Border.Style>
-                            <Style TargetType="Border">
-                                <Setter Property="Background" Value="Transparent"/>
-                                <Style.Triggers>
-                                    <Trigger Property="IsMouseOver" Value="True">
-                                        <Setter Property="Background" Value="#18FFFFFF"/>
-                                    </Trigger>
-                                </Style.Triggers>
-                            </Style>
-                        </Border.Style>
-                        <TextBlock Text="&#xE713;" FontFamily="Segoe MDL2 Assets" FontSize="14"
-                                   Foreground="{DynamicResource SecondaryText}"/>
+            <!-- Row 4: 대화 목록 (x:Name="ConversationPanel" — ChatWindow 프록시 대상) -->
+            <ScrollViewer Grid.Row="4" VerticalScrollBarVisibility="Auto"
+                          HorizontalScrollBarVisibility="Disabled">
+                <StackPanel x:Name="ConversationPanel" Margin="6,0"/>
+            </ScrollViewer>
+
+            <!-- Row 5: 전체 삭제 -->
+            <Border Grid.Row="5" BorderBrush="{DynamicResource SeparatorColor}" BorderThickness="0,1,0,0"
+                    Padding="0,4">
+                <Button x:Name="BtnDeleteAll" Style="{DynamicResource GhostBtn}"
+                        HorizontalAlignment="Center" VerticalAlignment="Center"
+                        Click="BtnDeleteAll_Click">
+                    <StackPanel Orientation="Horizontal">
+                        <TextBlock Text="&#xE74D;" FontFamily="Segoe MDL2 Assets" FontSize="11"
+                                   Foreground="#AA5555" VerticalAlignment="Center" Margin="0,0,6,0"/>
+                        <TextBlock Text="전체 삭제" FontSize="11" Foreground="#AA5555"/>
+                    </StackPanel>
+                </Button>
+            </Border>
+
+            <!-- Row 6: 사용자 계정 (x:Name 요소들 — ChatWindow SetupUserInfo()에서 직접 접근) -->
+            <Border Grid.Row="6" Margin="12,0,12,8">
+                <Grid>
+                    <Grid.ColumnDefinitions>
+                        <ColumnDefinition Width="Auto"/>
+                        <ColumnDefinition Width="*"/>
+                    </Grid.ColumnDefinitions>
+                    <Border Grid.Column="0" Width="34" Height="34" CornerRadius="17"
+                            Background="{DynamicResource AccentColor}" Margin="0,0,10,0">
+                        <TextBlock x:Name="UserInitialSidebar" Text="U" FontSize="14" FontWeight="Bold"
+                                   Foreground="White" HorizontalAlignment="Center" VerticalAlignment="Center"/>
                     </Border>
+                    <StackPanel Grid.Column="1" VerticalAlignment="Center">
+                        <TextBlock x:Name="UserNameText" Text="" FontSize="12" FontWeight="SemiBold"
+                                   Foreground="{DynamicResource PrimaryText}"
+                                   TextTrimming="CharacterEllipsis"/>
+                        <TextBlock x:Name="UserPcText" Text="" FontSize="10"
+                                   Foreground="{DynamicResource SecondaryText}"/>
+                    </StackPanel>
                 </Grid>
             </Border>
         </Grid>
diff --git a/src/AxCopilot/Views/Controls/AgentSidebarView.xaml.cs b/src/AxCopilot/Views/Controls/AgentSidebarView.xaml.cs
index d076b45..a8276cc 100644
--- a/src/AxCopilot/Views/Controls/AgentSidebarView.xaml.cs
+++ b/src/AxCopilot/Views/Controls/AgentSidebarView.xaml.cs
@@ -6,37 +6,39 @@ using System.Windows.Media.Animation;
 namespace AxCopilot.Views.Controls;
 
 /// <summary>
-/// Phase 32-B: 좌측 사이드바 (Claude.ai 스타일).
-/// 탭 세그먼트(Chat/Cowork/Code) + 새 대화 + 검색 + 대화 이력.
+/// Phase 17-UI-D: 좌측 사이드바 UserControl.
+/// 기존 SidebarPanel Grid를 대체. ChatWindow 프록시 패턴으로 기존 코드와 호환.
+/// 탭 세그먼트(Chat/Cowork/Code) + 카테고리 필터 + 대화 목록 + 사용자 계정.
 /// </summary>
 public partial class AgentSidebarView : UserControl
 {
-    private bool _isCollapsed;
     private string _activeTab = "Chat";
 
+    // ── 프록시 프로퍼티 (ChatWindow 기존 코드가 직접 참조) ─────────────────
+    internal StackPanel SidebarConversationPanel => ConversationPanel;
+    internal TextBox    SidebarSearchBox         => SearchBox;
+    internal TextBlock  SidebarCategoryIcon      => CategoryIcon;
+    internal TextBlock  SidebarCategoryLabel     => CategoryLabel;
+    internal Border     SidebarCategoryDropTarget => BtnCategoryDrop;
+    internal TextBlock  SidebarUserInitial        => UserInitialSidebar;
+    internal TextBlock  SidebarUserName           => UserNameText;
+    internal TextBlock  SidebarUserPc             => UserPcText;
+
+    // ── 이벤트 (ChatWindow가 구독) ─────────────────────────────────────────
     /// <summary>탭 전환 이벤트. 인자: 탭 이름 ("Chat", "Cowork", "Code").</summary>
-    public event EventHandler<string>? TabChanged;
+    public event EventHandler<string>? SidebarTabChanged;
 
     /// <summary>새 대화 요청 이벤트.</summary>
     public event EventHandler? NewChatRequested;
 
-    /// <summary>대화 선택 이벤트. 인자: 대화 ID.</summary>
-    public event EventHandler<string>? ConversationSelected;
-
     /// <summary>전체 삭제 요청 이벤트.</summary>
     public event EventHandler? DeleteAllRequested;
 
-    /// <summary>설정 패널 토글 요청 이벤트.</summary>
-    public event EventHandler? SettingsRequested;
+    /// <summary>카테고리 드롭다운 클릭 이벤트.</summary>
+    public event EventHandler? CategoryDropClicked;
 
-    /// <summary>접기/펼치기 토글 이벤트.</summary>
-    public event EventHandler<bool>? CollapseToggled;
-
-    /// <summary>사이드바가 접혀있는지 여부.</summary>
-    public bool IsCollapsed => _isCollapsed;
-
-    /// <summary>현재 활성 탭.</summary>
-    public string ActiveTab => _activeTab;
+    /// <summary>검색어 변경 이벤트.</summary>
+    public event TextChangedEventHandler? SearchTextChanged;
 
     public AgentSidebarView()
     {
@@ -44,189 +46,77 @@ public partial class AgentSidebarView : UserControl
         UpdateTabHighlight("Chat");
     }
 
-    /// <summary>탭을 외부에서 변경합니다.</summary>
+    // ── 외부 제어 ───────────────────────────────────────────────────────────
+
+    /// <summary>탭을 외부에서 변경합니다 (이벤트 발행 없음).</summary>
     public void SetActiveTab(string tab)
     {
         _activeTab = tab;
         UpdateTabHighlight(tab);
     }
 
-    /// <summary>대화 이력 목록을 갱신합니다.</summary>
-    public void RefreshConversations(IEnumerable<ConversationItem> items)
-    {
-        ConversationList.Children.Clear();
+    // ── XAML 이벤트 핸들러 ──────────────────────────────────────────────────
 
-        string? lastGroup = null;
-        foreach (var item in items)
-        {
-            var group = GetDateGroup(item.UpdatedAt);
-            if (group != lastGroup)
-            {
-                lastGroup = group;
-                var header = new TextBlock
-                {
-                    Text = group,
-                    FontSize = 11,
-                    FontWeight = FontWeights.SemiBold,
-                    Foreground = TryFindResource("SecondaryText") as Brush ?? Brushes.Gray,
-                    Margin = new Thickness(8, 12, 0, 4),
-                };
-                ConversationList.Children.Add(header);
-            }
-
-            var border = new Border
-            {
-                CornerRadius = new CornerRadius(6),
-                Padding = new Thickness(10, 8, 10, 8),
-                Margin = new Thickness(0, 1, 0, 1),
-                Cursor = System.Windows.Input.Cursors.Hand,
-                Tag = item.Id,
-                Background = item.IsActive
-                    ? (TryFindResource("ItemHoverBackground") as Brush ?? Brushes.Transparent)
-                    : Brushes.Transparent,
-            };
-
-            var title = new TextBlock
-            {
-                Text = item.Title,
-                FontSize = 12,
-                Foreground = TryFindResource("PrimaryText") as Brush ?? Brushes.White,
-                TextTrimming = TextTrimming.CharacterEllipsis,
-                MaxWidth = 200,
-            };
-
-            border.Child = title;
-            border.MouseLeftButtonUp += (s, e) =>
-            {
-                if (s is Border b && b.Tag is string id)
-                    ConversationSelected?.Invoke(this, id);
-            };
-
-            // 호버 효과
-            border.MouseEnter += (s, _) =>
-            {
-                if (s is Border b)
-                    b.Background = TryFindResource("ItemHoverBackground") as Brush ?? Brushes.Transparent;
-            };
-            border.MouseLeave += (s, _) =>
-            {
-                if (s is Border b && b.Tag is string id)
-                    b.Background = items.Any(i => i.Id == id && i.IsActive)
-                        ? (TryFindResource("ItemHoverBackground") as Brush ?? Brushes.Transparent)
-                        : Brushes.Transparent;
-            };
-
-            ConversationList.Children.Add(border);
-        }
-    }
-
-    #region ── 이벤트 핸들러 ──
-
-    private void TabChat_Click(object sender, System.Windows.Input.MouseButtonEventArgs e)
-    {
-        _activeTab = "Chat";
-        UpdateTabHighlight("Chat");
-        TabChanged?.Invoke(this, "Chat");
-    }
-
-    private void TabCowork_Click(object sender, System.Windows.Input.MouseButtonEventArgs e)
-    {
-        _activeTab = "Cowork";
-        UpdateTabHighlight("Cowork");
-        TabChanged?.Invoke(this, "Cowork");
-    }
-
-    private void TabCode_Click(object sender, System.Windows.Input.MouseButtonEventArgs e)
-    {
-        _activeTab = "Code";
-        UpdateTabHighlight("Code");
-        TabChanged?.Invoke(this, "Code");
-    }
-
-    private void BtnNewChat_Click(object sender, System.Windows.Input.MouseButtonEventArgs e)
+    private void BtnNewChat_Click(object sender, RoutedEventArgs e)
         => NewChatRequested?.Invoke(this, EventArgs.Empty);
 
-    private void BtnDeleteAll_Click(object sender, System.Windows.Input.MouseButtonEventArgs e)
+    private void SidebarTabChat_Click(object sender, System.Windows.Input.MouseButtonEventArgs e)
+    {
+        if (_activeTab == "Chat") return;
+        _activeTab = "Chat";
+        UpdateTabHighlight("Chat");
+        SidebarTabChanged?.Invoke(this, "Chat");
+    }
+
+    private void SidebarTabCowork_Click(object sender, System.Windows.Input.MouseButtonEventArgs e)
+    {
+        if (_activeTab == "Cowork") return;
+        _activeTab = "Cowork";
+        UpdateTabHighlight("Cowork");
+        SidebarTabChanged?.Invoke(this, "Cowork");
+    }
+
+    private void SidebarTabCode_Click(object sender, System.Windows.Input.MouseButtonEventArgs e)
+    {
+        if (_activeTab == "Code") return;
+        _activeTab = "Code";
+        UpdateTabHighlight("Code");
+        SidebarTabChanged?.Invoke(this, "Code");
+    }
+
+    private void SearchBox_TextChanged(object sender, TextChangedEventArgs e)
+        => SearchTextChanged?.Invoke(sender, e);
+
+    private void BtnCategoryDrop_Click(object sender, System.Windows.Input.MouseButtonEventArgs e)
+        => CategoryDropClicked?.Invoke(this, EventArgs.Empty);
+
+    private void BtnDeleteAll_Click(object sender, RoutedEventArgs e)
         => DeleteAllRequested?.Invoke(this, EventArgs.Empty);
 
-    private void BtnSettings_Click(object sender, System.Windows.Input.MouseButtonEventArgs e)
-        => SettingsRequested?.Invoke(this, EventArgs.Empty);
-
-    private void BtnCollapse_Click(object sender, System.Windows.Input.MouseButtonEventArgs e)
-    {
-        _isCollapsed = !_isCollapsed;
-        AnimateCollapse(_isCollapsed);
-        CollapseToggled?.Invoke(this, _isCollapsed);
-    }
-
-    private void TxtSearch_TextChanged(object sender, TextChangedEventArgs e)
-    {
-        // 검색 필터링은 ChatWindow에서 처리
-    }
-
-    #endregion
-
-    #region ── UI 헬퍼 ──
+    // ── UI 헬퍼 ─────────────────────────────────────────────────────────────
 
     private void UpdateTabHighlight(string tab)
     {
-        var accentBrush = TryFindResource("AccentColor") as Brush ?? Brushes.DodgerBlue;
+        var accentBrush = TryFindResource("AccentColor") as Brush
+                          ?? new SolidColorBrush(Color.FromRgb(0x4B, 0x5E, 0xFC));
         var transparentBrush = Brushes.Transparent;
 
-        TabChat.Background = tab == "Chat" ? accentBrush : transparentBrush;
-        TabCowork.Background = tab == "Cowork" ? accentBrush : transparentBrush;
-        TabCode.Background = tab == "Code" ? accentBrush : transparentBrush;
+        SidebarTabChat.Background   = tab == "Chat"   ? accentBrush : transparentBrush;
+        SidebarTabCowork.Background = tab == "Cowork" ? accentBrush : transparentBrush;
+        SidebarTabCode.Background   = tab == "Code"   ? accentBrush : transparentBrush;
 
-        // 선택 탭 텍스트 색상 조정
-        SetTabTextColor(TabChat, tab == "Chat");
-        SetTabTextColor(TabCowork, tab == "Cowork");
-        SetTabTextColor(TabCode, tab == "Code");
+        SetTabTextColor(SidebarTabChat,   tab == "Chat");
+        SetTabTextColor(SidebarTabCowork, tab == "Cowork");
+        SetTabTextColor(SidebarTabCode,   tab == "Code");
     }
 
-    private void SetTabTextColor(Border tab, bool isActive)
+    private void SetTabTextColor(Border tabBorder, bool isActive)
     {
-        if (tab.Child is TextBlock txt)
+        if (tabBorder.Child is TextBlock txt)
         {
             txt.Foreground = isActive
                 ? Brushes.White
                 : (TryFindResource("PrimaryText") as Brush ?? Brushes.White);
         }
     }
-
-    private void AnimateCollapse(bool collapse)
-    {
-        var targetWidth = collapse ? 48.0 : 260.0;
-        var anim = new DoubleAnimation(Width, targetWidth, TimeSpan.FromMilliseconds(180))
-        {
-            EasingFunction = new QuadraticEase { EasingMode = EasingMode.EaseInOut }
-        };
-        BeginAnimation(WidthProperty, anim);
-
-        // 접힌 상태: 제목/검색/대화 이력 숨김
-        var vis = collapse ? Visibility.Collapsed : Visibility.Visible;
-        TxtTitle.Visibility = vis;
-        TxtSearch.Visibility = vis;
-        ConversationList.Visibility = vis;
-    }
-
-    private static string GetDateGroup(DateTime date)
-    {
-        var today = DateTime.Today;
-        if (date.Date == today) return "오늘";
-        if (date.Date == today.AddDays(-1)) return "어제";
-        if (date.Date > today.AddDays(-7)) return "이전 7일";
-        if (date.Date > today.AddDays(-30)) return "이전 30일";
-        return date.ToString("yyyy-MM");
-    }
-
-    #endregion
-
-    /// <summary>대화 이력 표시용 DTO.</summary>
-    public class ConversationItem
-    {
-        public string Id { get; set; } = "";
-        public string Title { get; set; } = "";
-        public DateTime UpdatedAt { get; set; }
-        public bool IsActive { get; set; }
-    }
 }