diff --git a/Projects/DVDesign/Sources/Components/DVProjectContainer.swift b/Projects/DVDesign/Sources/Components/DVProjectContainer.swift
index 0c91707..505123c 100644
--- a/Projects/DVDesign/Sources/Components/DVProjectContainer.swift
+++ b/Projects/DVDesign/Sources/Components/DVProjectContainer.swift
@@ -8,6 +8,8 @@ public struct DVProjectContainer: View {
 
     // MARK: - Properties
 
+    static let projectIconSystemName = "tray"
+
     public let name: String
     public let count: Int
 
@@ -37,7 +39,7 @@ public struct DVProjectContainer: View {
 extension DVProjectContainer {
 
     private var projectIcon: some View {
-        Image(systemName: "tray")
+        Image(systemName: DVProjectContainer.projectIconSystemName)
             .dvFont(.captionLG)
             .foregroundStyle(Color.dv(.gray900))
     }
diff --git a/Projects/DVDesign/Sources/Components/DVProjectRenameContainer.swift b/Projects/DVDesign/Sources/Components/DVProjectRenameContainer.swift
new file mode 100644
index 0000000..bf831e1
--- /dev/null
+++ b/Projects/DVDesign/Sources/Components/DVProjectRenameContainer.swift
@@ -0,0 +1,58 @@
+// Copyright © 2026 Devault. All rights reserved
+
+import SwiftUI
+
+/// 프로젝트 행 인라인 리네임 컴포넌트.
+/// DVProjectContainer와 동일한 leading icon + 레이아웃에서 이름 부분을 TextField로 교체한다.
+public struct DVProjectRenameContainer: View {
+
+    // MARK: - Properties
+
+    @Binding public var text: String
+    public var onSubmit: () -> Void
+    public var onCancel: () -> Void
+
+    @FocusState private var isFocused: Bool
+    @State private var isHandled = false
+
+    // MARK: - Init
+
+    public init(
+        text: Binding<String>,
+        onSubmit: @escaping () -> Void,
+        onCancel: @escaping () -> Void
+    ) {
+        self._text = text
+        self.onSubmit = onSubmit
+        self.onCancel = onCancel
+    }
+
+    // MARK: - Body
+
+    public var body: some View {
+        HStack(spacing: 4) {
+            Image(systemName: DVProjectContainer.projectIconSystemName)
+                .dvFont(.captionLG)
+                .foregroundStyle(Color.dv(.gray900))
+            TextField("", text: $text)
+                .dvFont(.bodyMD)
+                .textFieldStyle(.plain)
+                .focused($isFocused)
+                .onSubmit {
+                    isHandled = true
+                    onSubmit()
+                }
+                .onExitCommand {
+                    isHandled = true
+                    onCancel()
+                }
+        }
+        .padding(2)
+        .frame(minWidth: 120, alignment: .leading)
+        .onAppear { isFocused = true }
+        .onChange(of: isFocused) { _, focused in
+            guard !focused, !isHandled else { return }
+            onSubmit()
+        }
+    }
+}
diff --git a/Projects/DVPresentation/Resources/Localizable.xcstrings b/Projects/DVPresentation/Resources/Localizable.xcstrings
index 91840cf..4a7fd80 100644
--- a/Projects/DVPresentation/Resources/Localizable.xcstrings
+++ b/Projects/DVPresentation/Resources/Localizable.xcstrings
@@ -3,10 +3,6 @@
   "strings" : {
     "Access your secrets on all your\nApple devices, securely encrypted." : {
 
-    },
-    "Content" : {
-      "comment" : "The title of the main content section in the preview.",
-      "isCommentAutoGenerated" : true
     },
     "Create Project" : {
 
@@ -52,6 +48,9 @@
     },
     "목록을 불러오지 못했어요" : {
 
+    },
+    "불러오지 못했어요" : {
+
     },
     "시크릿이 없어요" : {
 
diff --git a/Projects/DVPresentation/Sources/Dependencies/SidebarClient.swift b/Projects/DVPresentation/Sources/Dependencies/SidebarClient.swift
new file mode 100644
index 0000000..929f0ce
--- /dev/null
+++ b/Projects/DVPresentation/Sources/Dependencies/SidebarClient.swift
@@ -0,0 +1,30 @@
+// Copyright © 2026 Devault. All rights reserved
+
+import ComposableArchitecture
+import Foundation
+
+@DependencyClient
+public struct SidebarClient: Sendable {
+  public var fetchProjects: @Sendable () async throws -> [ProjectItem]
+  public var createProject: @Sendable (_ name: String) async throws -> ProjectItem
+  public var renameProject: @Sendable (_ id: ProjectItem.ID, _ name: String) async throws -> ProjectItem
+  public var deleteProject: @Sendable (_ id: ProjectItem.ID) async throws -> Void
+}
+
+extension SidebarClient: TestDependencyKey {
+  public static let testValue = SidebarClient()
+
+  public static let previewValue = SidebarClient(
+    fetchProjects: { ProjectItem.previews },
+    createProject: { name in ProjectItem(id: UUID(), name: name) },
+    renameProject: { id, name in ProjectItem(id: id, name: name) },
+    deleteProject: { _ in }
+  )
+}
+
+extension DependencyValues {
+  public var sidebarClient: SidebarClient {
+    get { self[SidebarClient.self] }
+    set { self[SidebarClient.self] = newValue }
+  }
+}
diff --git a/Projects/DVPresentation/Sources/Features/AddToProject/AddToProjectFeature.swift b/Projects/DVPresentation/Sources/Features/AddToProject/AddToProjectFeature.swift
index c566b58..520ff22 100644
--- a/Projects/DVPresentation/Sources/Features/AddToProject/AddToProjectFeature.swift
+++ b/Projects/DVPresentation/Sources/Features/AddToProject/AddToProjectFeature.swift
@@ -15,8 +15,8 @@ public struct AddToProjectFeature {
   @ObservableState
   public struct State: Equatable {
     public let secretID: Secret.ID
-    public internal(set) var projectsState: LoadingState<IdentifiedArrayOf<Project>, ProjectUseCaseError> = .idle
-    public internal(set) var selectedProjectID: Project.ID?
+    public internal(set) var projectsState: LoadingState<IdentifiedArrayOf<ProjectItem>, SidebarError> = .idle
+    public internal(set) var selectedProjectID: ProjectItem.ID?
     @Presents var destination: Destination.State?
     @Presents var alert: AlertState<Action.Alert>?
 
@@ -32,14 +32,14 @@ public struct AddToProjectFeature {
     // MARK: - View
 
     case task
-    case didSelectProject(id: Project.ID?)
+    case didSelectProject(id: ProjectItem.ID?)
     case didTapCreateNewProject
     case didTapDone
     case didTapCancel
 
     // MARK: - Internal
 
-    case projectsResponse(Result<[Project], ProjectUseCaseError>)
+    case projectsResponse(Result<[ProjectItem], SidebarError>)
     case linkResponse(Result<Secret.ID, SecretUseCaseError>)
 
     // MARK: - Child
@@ -67,6 +67,7 @@ public struct AddToProjectFeature {
 
   // MARK: - Dependencies
 
+  @Dependency(\.sidebarClient) var sidebarClient
   @Dependency(\.secretClient) var secretClient
   @Dependency(\.dismiss) var dismiss
 
@@ -83,10 +84,12 @@ public struct AddToProjectFeature {
         state.projectsState = .loading
         return .run { send in
           do {
-            let projects = try await secretClient.fetchProjects()
+            let projects = try await sidebarClient.fetchProjects()
             await send(.projectsResponse(.success(projects)))
+          } catch let error as SidebarError {
+            await send(.projectsResponse(.failure(error)))
           } catch {
-            await send(.projectsResponse(.failure(ProjectUseCaseError.map(error))))
+            await send(.projectsResponse(.failure(.fetchFailed)))
           }
         }
 
@@ -106,14 +109,14 @@ public struct AddToProjectFeature {
         state.destination = .createProject(CreateProjectFeature.State())
         return .none
 
-      case .destination(.presented(.createProject(.delegate(.projectCreated(let project))))):
-        var projects: IdentifiedArrayOf<Project> = {
+      case .destination(.presented(.createProject(.delegate(.projectCreated(let item))))):
+        var projects: IdentifiedArrayOf<ProjectItem> = {
           if case let .loaded(projects) = state.projectsState { return projects }
           return []
         }()
-        projects.append(project)
+        projects.append(item)
         state.projectsState = .loaded(projects)
-        state.selectedProjectID = project.id
+        state.selectedProjectID = item.id
         return .none
 
       case .destination:
diff --git a/Projects/DVPresentation/Sources/Features/AddToProject/AddToProjectView.swift b/Projects/DVPresentation/Sources/Features/AddToProject/AddToProjectView.swift
index b87d8e7..1edf0c2 100644
--- a/Projects/DVPresentation/Sources/Features/AddToProject/AddToProjectView.swift
+++ b/Projects/DVPresentation/Sources/Features/AddToProject/AddToProjectView.swift
@@ -5,7 +5,6 @@ import SwiftUI
 
 import ComposableArchitecture
 import DVDesign
-import DVDomain
 
 // MARK: - AddToProjectView
 
@@ -130,7 +129,7 @@ extension AddToProjectView {
     return projects[id: id]?.name
   }
 
-  private var projects: IdentifiedArrayOf<Project> {
+  private var projects: IdentifiedArrayOf<ProjectItem> {
     if case let .loaded(projects) = store.projectsState {
       return projects
     }
diff --git a/Projects/DVPresentation/Sources/Features/CreateProject/CreateProjectFeature.swift b/Projects/DVPresentation/Sources/Features/CreateProject/CreateProjectFeature.swift
index 09509aa..52451a6 100644
--- a/Projects/DVPresentation/Sources/Features/CreateProject/CreateProjectFeature.swift
+++ b/Projects/DVPresentation/Sources/Features/CreateProject/CreateProjectFeature.swift
@@ -3,7 +3,6 @@
 import Foundation
 
 import ComposableArchitecture
-import DVDomain
 
 // MARK: - CreateProjectFeature
 
@@ -33,7 +32,7 @@ public struct CreateProjectFeature {
 
     // MARK: - Internal
 
-    case createResponse(Result<Project, ProjectUseCaseError>)
+    case createResponse(Result<ProjectItem, SidebarError>)
 
     // MARK: - Child
 
@@ -44,7 +43,7 @@ public struct CreateProjectFeature {
     case delegate(Delegate)
 
     public enum Delegate: Equatable {
-      case projectCreated(Project)
+      case projectCreated(ProjectItem)
     }
 
     public enum Alert: Equatable {}
@@ -52,7 +51,7 @@ public struct CreateProjectFeature {
 
   // MARK: - Dependencies
 
-  @Dependency(\.secretClient) var secretClient
+  @Dependency(\.sidebarClient) var sidebarClient
   @Dependency(\.dismiss) var dismiss
 
   // MARK: - Init
@@ -76,20 +75,33 @@ public struct CreateProjectFeature {
         state.isCreating = true
         return .run { send in
           do {
-            let project = try await secretClient.createProject(trimmedName)
-            await send(.createResponse(.success(project)))
+            let item = try await sidebarClient.createProject(trimmedName)
+            await send(.createResponse(.success(item)))
+          } catch let error as SidebarError {
+            await send(.createResponse(.failure(error)))
           } catch {
-            await send(.createResponse(.failure(ProjectUseCaseError.map(error))))
+            await send(.createResponse(.failure(.createFailed)))
           }
         }
 
-      case .createResponse(.success(let project)):
+      case .createResponse(.success(let item)):
         state.isCreating = false
         return .run { send in
-          await send(.delegate(.projectCreated(project)))
+          await send(.delegate(.projectCreated(item)))
           await dismiss()
         }
 
+      case .createResponse(.failure(.nameTaken)):
+        state.isCreating = false
+        state.alert = AlertState {
+          TextState("이미 사용 중인 프로젝트 이름이에요")
+        } actions: {
+          ButtonState(role: .cancel) { TextState("확인") }
+        } message: {
+          TextState("다른 이름을 입력해주세요.")
+        }
+        return .none
+
       case .createResponse(.failure):
         state.isCreating = false
         state.alert = AlertState {
diff --git a/Projects/DVPresentation/Sources/Features/CreateSecret/Model/CreatableSecretType.swift b/Projects/DVPresentation/Sources/Features/CreateSecret/Model/CreatableSecretType.swift
index 4d35646..71e76d4 100644
--- a/Projects/DVPresentation/Sources/Features/CreateSecret/Model/CreatableSecretType.swift
+++ b/Projects/DVPresentation/Sources/Features/CreateSecret/Model/CreatableSecretType.swift
@@ -4,7 +4,7 @@ import DVDomain
 import Foundation
 import SwiftUI
 
-enum CreatableSecretType: String, CaseIterable, Hashable {
+public enum CreatableSecretType: String, CaseIterable, Hashable {
     case apiKeyToken
     case oauth
     case database
diff --git a/Projects/DVPresentation/Sources/Features/Main/MainFeature.swift b/Projects/DVPresentation/Sources/Features/Main/MainFeature.swift
index 446f49c..ad096e8 100644
--- a/Projects/DVPresentation/Sources/Features/Main/MainFeature.swift
+++ b/Projects/DVPresentation/Sources/Features/Main/MainFeature.swift
@@ -1,8 +1,7 @@
 // Copyright © 2026 Devault. All rights reserved
 
-import SwiftUI
-
 import ComposableArchitecture
+import SwiftUI
 
 // MARK: - MainFeature
 
@@ -15,6 +14,10 @@ public struct MainFeature {
   public struct State: Equatable {
     public var columnVisibility: NavigationSplitViewVisibility = .all
     var sidebar: SidebarFeature.State = .init()
+    var secretList: SecretListFeature.State = .init(collection: .all)
+    /// sheet가 아닌 2-column NavigationSplitView 전환 용도이므로 @Presents 미사용
+    var selectSecretType: SelectSecretTypeFeature.State?
+    @Presents var createProject: CreateProjectFeature.State?
 
     public init() {}
   }
@@ -31,6 +34,9 @@ public struct MainFeature {
     // MARK: - Child
 
     case sidebar(SidebarFeature.Action)
+    case secretList(SecretListFeature.Action)
+    case selectSecretType(SelectSecretTypeFeature.Action)
+    case createProject(PresentationAction<CreateProjectFeature.Action>)
 
     // MARK: - Delegate
 
@@ -50,6 +56,9 @@ public struct MainFeature {
     Scope(state: \.sidebar, action: \.sidebar) {
       SidebarFeature()
     }
+    Scope(state: \.secretList, action: \.secretList) {
+      SecretListFeature()
+    }
     Reduce { state, action in
       switch action {
       case .binding:
@@ -64,10 +73,37 @@ public struct MainFeature {
       case .sidebar:
         return .none
 
+      case .secretList:
+        return .none
+
+      case .selectSecretType(.delegate(.typeSelected)):
+        // TODO: createSecret 연결
+        return .none
+
+      case .selectSecretType:
+        return .none
+
+      case .createProject(.presented(.delegate(.projectCreated(let item)))):
+        state.createProject = nil
+        if !state.sidebar.isCreatingSecret {
+          state.sidebar.selection = .project(id: item.id)
+          state.secretList = .init(collection: .project(id: item.id), projectName: item.name)
+        }
+        return .send(.sidebar(.task))
+
+      case .createProject:
+        return .none
+
       case .delegate:
         return .none
       }
     }
+    .ifLet(\.selectSecretType, action: \.selectSecretType) {
+      SelectSecretTypeFeature()
+    }
+    .ifLet(\.$createProject, action: \.createProject) {
+      CreateProjectFeature()
+    }
   }
 }
 
@@ -80,17 +116,46 @@ extension MainFeature {
     delegate: SidebarFeature.Action.Delegate
   ) -> Effect<Action> {
     switch delegate {
-    case .selectionChanged:
-      return .none
+    case .selectionChanged(let selection):
+      state.selectSecretType = nil
+      state.secretList = makeSecretListState(selection: selection, projects: state.sidebar.projects)
+      return .send(.sidebar(.setCreatingSecret(false)))
 
     case .addButtonTapped:
-      return .none
+      state.selectSecretType = .init()
+      return .send(.sidebar(.setCreatingSecret(true)))
 
-    case .settingsButtonTapped:
+    case .addProjectTapped:
+      state.createProject = .init()
       return .none
 
-    case .addProjectTapped:
+    case .projectRenamed(let item):
+      if case .project(id: item.id) = state.sidebar.selection {
+        state.secretList = .init(collection: .project(id: item.id), projectName: item.name)
+      }
       return .none
     }
   }
+
+  private func makeSecretListState(
+    selection: SidebarSelection,
+    projects: IdentifiedArrayOf<ProjectItem>
+  ) -> SecretListFeature.State {
+    switch selection {
+    case .filter(.all):
+      return .init(collection: .all)
+    case .filter(.starred):
+      return .init(collection: .liked)
+    case .filter(.notice):
+      // TODO: 도메인 레이어에 .notice collection 추가 후 연결
+      return .init(collection: .all)
+    case .filter(.expired):
+      return .init(collection: .expired(referenceDate: Date()))
+    case .filter(.deleted):
+      return .init(collection: .deleted)
+    case .project(id: let id):
+      let projectName = projects[id: id]?.name
+      return .init(collection: .project(id: id), projectName: projectName)
+    }
+  }
 }
diff --git a/Projects/DVPresentation/Sources/Features/Main/MainView.swift b/Projects/DVPresentation/Sources/Features/Main/MainView.swift
index 361e401..96463f5 100644
--- a/Projects/DVPresentation/Sources/Features/Main/MainView.swift
+++ b/Projects/DVPresentation/Sources/Features/Main/MainView.swift
@@ -19,6 +19,11 @@ struct MainView: View {
     content
       .dvScreenBackground()
       .task { store.send(.task) }
+      .sheet(
+        item: $store.scope(state: \.createProject, action: \.createProject)
+      ) { createProjectStore in
+        CreateProjectView(store: createProjectStore)
+      }
   }
 }
 
@@ -26,25 +31,38 @@ struct MainView: View {
 
 extension MainView {
 
+  @ViewBuilder
   private var content: some View {
-    NavigationSplitView(columnVisibility: $store.columnVisibility) {
-      sidebar
-    } content: {
-      contentColumn
-    } detail: {
-      detailColumn
+    if let selectStore = store.scope(state: \.selectSecretType, action: \.selectSecretType) {
+      // 사이드바 + 타입 선택 그리드 (2컬럼)
+      NavigationSplitView {
+        sidebarColumn
+      } detail: {
+        SelectSecretTypeView(store: selectStore)
+      }
+      .navigationSplitViewStyle(.balanced)
+      .toolbarBackground(.hidden, for: .windowToolbar)
+    } else {
+      // 사이드바 + 시크릿 목록 + 상세 (3컬럼)
+      NavigationSplitView(columnVisibility: $store.columnVisibility) {
+        sidebarColumn
+      } content: {
+        contentColumn
+      } detail: {
+        detailColumn
+      }
+      .navigationSplitViewStyle(.balanced)
+      .toolbarBackground(.hidden, for: .windowToolbar)
     }
-    .navigationSplitViewStyle(.balanced)
-    .toolbarBackground(.hidden, for: .windowToolbar)
   }
 
-  private var sidebar: some View {
+  private var sidebarColumn: some View {
     SidebarView(store: store.scope(state: \.sidebar, action: \.sidebar))
       .navigationSplitViewColumnWidth(min: 200, ideal: 250, max: 270)
   }
 
   private var contentColumn: some View {
-    Text("Content")
+    SecretListView(store: store.scope(state: \.secretList, action: \.secretList))
       .navigationTitle("")
   }
 
diff --git a/Projects/DVPresentation/Sources/Features/SelectSecretType/SelectSecretTypeFeature.swift b/Projects/DVPresentation/Sources/Features/SelectSecretType/SelectSecretTypeFeature.swift
index d2aef13..8df08dc 100644
--- a/Projects/DVPresentation/Sources/Features/SelectSecretType/SelectSecretTypeFeature.swift
+++ b/Projects/DVPresentation/Sources/Features/SelectSecretType/SelectSecretTypeFeature.swift
@@ -5,18 +5,18 @@ import ComposableArchitecture
 // MARK: - SelectSecretTypeFeature
 
 @Reducer
-struct SelectSecretTypeFeature {
+public struct SelectSecretTypeFeature {
 
     // MARK: - State
 
     @ObservableState
-    struct State: Equatable {
-        init() {}
+    public struct State: Equatable {
+        public init() {}
     }
 
     // MARK: - Action
 
-    enum Action: Equatable {
+    public enum Action: Equatable {
 
         // MARK: - View
 
@@ -26,18 +26,18 @@ struct SelectSecretTypeFeature {
 
         case delegate(Delegate)
 
-        enum Delegate: Equatable {
+        public enum Delegate: Equatable {
             case typeSelected(CreatableSecretType)
         }
     }
 
     // MARK: - Init
 
-    init() {}
+    public init() {}
 
     // MARK: - Body
 
-    var body: some ReducerOf<Self> {
+    public var body: some ReducerOf<Self> {
         Reduce { state, action in
             switch action {
             case .didSelectType(let type):
diff --git a/Projects/DVPresentation/Sources/Features/Sidebar/Error/SidebarError.swift b/Projects/DVPresentation/Sources/Features/Sidebar/Error/SidebarError.swift
new file mode 100644
index 0000000..8856e95
--- /dev/null
+++ b/Projects/DVPresentation/Sources/Features/Sidebar/Error/SidebarError.swift
@@ -0,0 +1,9 @@
+// Copyright © 2026 Devault. All rights reserved
+
+public enum SidebarError: Error, Equatable {
+  case fetchFailed
+  case createFailed
+  case renameFailed
+  case deleteFailed
+  case nameTaken
+}
diff --git a/Projects/DVPresentation/Sources/Features/Sidebar/Model/ProjectItem+Mapping.swift b/Projects/DVPresentation/Sources/Features/Sidebar/Model/ProjectItem+Mapping.swift
new file mode 100644
index 0000000..c00c207
--- /dev/null
+++ b/Projects/DVPresentation/Sources/Features/Sidebar/Model/ProjectItem+Mapping.swift
@@ -0,0 +1,9 @@
+// Copyright © 2026 Devault. All rights reserved
+
+import DVDomain
+
+public extension ProjectItem {
+  init(_ project: Project) {
+    self.init(id: project.id, name: project.name)
+  }
+}
diff --git a/Projects/DVPresentation/Sources/Features/Sidebar/Model/ProjectItem.swift b/Projects/DVPresentation/Sources/Features/Sidebar/Model/ProjectItem.swift
new file mode 100644
index 0000000..b48aeee
--- /dev/null
+++ b/Projects/DVPresentation/Sources/Features/Sidebar/Model/ProjectItem.swift
@@ -0,0 +1,23 @@
+// Copyright © 2026 Devault. All rights reserved
+
+import Foundation
+
+public struct ProjectItem: Equatable, Identifiable, Sendable {
+  public let id: UUID
+  public let name: String
+
+  public init(id: UUID, name: String) {
+    self.id = id
+    self.name = name
+  }
+}
+
+// MARK: - Preview Fixtures
+
+public extension ProjectItem {
+  static let previews: [ProjectItem] = [
+    .init(id: UUID(uuidString: "00000000-0000-0000-0000-000000000001")!, name: "Backend"),
+    .init(id: UUID(uuidString: "00000000-0000-0000-0000-000000000002")!, name: "Infrastructure"),
+    .init(id: UUID(uuidString: "00000000-0000-0000-0000-000000000003")!, name: "Mobile"),
+  ]
+}
diff --git a/Projects/DVPresentation/Sources/Features/Sidebar/SidebarFeature.swift b/Projects/DVPresentation/Sources/Features/Sidebar/SidebarFeature.swift
index 06a4f94..512e756 100644
--- a/Projects/DVPresentation/Sources/Features/Sidebar/SidebarFeature.swift
+++ b/Projects/DVPresentation/Sources/Features/Sidebar/SidebarFeature.swift
@@ -32,14 +32,13 @@ public enum SidebarFilter: Equatable, CaseIterable, Hashable {
     case .deleted: "trash"
     }
   }
-
 }
 
 // MARK: - SidebarSelection
 
 public enum SidebarSelection: Equatable {
   case filter(SidebarFilter)
-  case project(Int)
+  case project(id: ProjectItem.ID)
 }
 
 // MARK: - SidebarFeature
@@ -53,6 +52,18 @@ public struct SidebarFeature {
   public struct State: Equatable {
     public internal(set) var selection: SidebarSelection = .filter(.all)
     public internal(set) var isProjectSectionExpanded: Bool = true
+    public internal(set) var isCreatingSecret: Bool = false
+    var projectsState: LoadingState<IdentifiedArrayOf<ProjectItem>, SidebarError> = .idle
+    var renamingProjectID: ProjectItem.ID?
+    var renameText: String = ""
+    var deletingProjectID: ProjectItem.ID?
+    @Presents var alert: AlertState<Action.Alert>?
+
+    // computed property — LoadingState에서 추출. 외부 참조(MainFeature, View)에서 LoadingState를 몰라도 됨
+    var projects: IdentifiedArrayOf<ProjectItem> {
+      if case .loaded(let projects) = projectsState { return projects }
+      return []
+    }
 
     public init() {}
   }
@@ -66,22 +77,49 @@ public struct SidebarFeature {
     case task
     case didSelect(SidebarSelection)
     case didTapAddButton
-    case didTapSettingsButton
     case didTapAddProject
     case didToggleProjectSection
+    case didTapRename(id: ProjectItem.ID)
+    case didChangeRenameText(String)
+    case didConfirmRename
+    case didCancelRename
+    case didTapDelete(id: ProjectItem.ID)
+    case setCreatingSecret(Bool)
+
+    // MARK: - Internal
+
+    case projectsResponse(Result<[ProjectItem], SidebarError>)
+    case renameResponse(Result<ProjectItem, SidebarError>)
+    case deleteResponse(Result<ProjectItem.ID, SidebarError>)
+
+    // MARK: - Child
+
+    case alert(PresentationAction<Alert>)
 
     // MARK: - Delegate
 
     case delegate(Delegate)
 
+    public enum Alert: Equatable {
+      case confirmDelete
+    }
+
     public enum Delegate: Equatable {
       case selectionChanged(SidebarSelection)
       case addButtonTapped
-      case settingsButtonTapped
       case addProjectTapped
+      case projectRenamed(ProjectItem)
     }
   }
 
+  // MARK: - CancelID (E5)
+
+  private enum CancelID { case fetch }
+
+  // MARK: - Dependencies
+
+  @Dependency(\.sidebarClient) var sidebarClient
+
   // MARK: - Init
 
   public init() {}
@@ -92,6 +130,26 @@ public struct SidebarFeature {
     Reduce { state, action in
       switch action {
       case .task:
+        state.projectsState = .loading
+        return .run { send in
+          do {
+            let projects = try await sidebarClient.fetchProjects()
+            await send(.projectsResponse(.success(projects)))
+          } catch let error as SidebarError {
+            await send(.projectsResponse(.failure(error)))
+          } catch {
+            await send(.projectsResponse(.failure(.fetchFailed)))
+          }
+        }
+        .cancellable(id: CancelID.fetch, cancelInFlight: true)
+
+      case .projectsResponse(.success(let projects)):
+        let sorted = projects.sorted { $0.name.localizedCompare($1.name) == .orderedAscending }
+        state.projectsState = .loaded(IdentifiedArray(uniqueElements: sorted))
+        return .none
+
+      case .projectsResponse(.failure(let error)):
+        state.projectsState = .failed(error)
         return .none
 
       case .didSelect(let selection):
@@ -101,9 +159,6 @@ public struct SidebarFeature {
       case .didTapAddButton:
         return .send(.delegate(.addButtonTapped))
 
-      case .didTapSettingsButton:
-        return .send(.delegate(.settingsButtonTapped))
-
       case .didTapAddProject:
         return .send(.delegate(.addProjectTapped))
 
@@ -111,9 +166,142 @@ public struct SidebarFeature {
         state.isProjectSectionExpanded.toggle()
         return .none
 
+      case .didTapRename(id: let id):
+        guard let project = state.projects[id: id] else { return .none }
+        state.renamingProjectID = id
+        state.renameText = project.name
+        return .none
+
+      case .didChangeRenameText(let text):
+        state.renameText = text
+        return .none
+
+      case .setCreatingSecret(let value):
+        state.isCreatingSecret = value
+        return .none
+
+      case .didConfirmRename:
+        guard let id = state.renamingProjectID else { return .none }
+        let name = state.renameText
+        state.renamingProjectID = nil
+        state.renameText = ""
+        return .run { [id, name] send in  // 캡처 리스트 명시
+          do {
+            let updated = try await sidebarClient.renameProject(id, name)
+            await send(.renameResponse(.success(updated)))
+          } catch let error as SidebarError {
+            await send(.renameResponse(.failure(error)))
+          } catch {
+            await send(.renameResponse(.failure(.renameFailed)))
+          }
+        }
+
+      case .didCancelRename:
+        state.renamingProjectID = nil
+        state.renameText = ""
+        return .none
+
+      case .renameResponse(.success(let updated)):
+        return .concatenate(
+          .send(.delegate(.projectRenamed(updated))),
+          .send(.task)
+        )
+
+      case .renameResponse(.failure(.nameTaken)):
+        state.alert = makeRenameNameTakenAlert()
+        return .none
+
+      case .renameResponse(.failure):
+        state.alert = makeRenameFailedAlert()
+        return .none
+
+      case .didTapDelete(id: let id):
+        guard let project = state.projects[id: id] else { return .none }
+        state.deletingProjectID = id
+        state.alert = makeDeleteAlert(for: project)  // helper로 분리
+        return .none
+
+      case .alert(.presented(.confirmDelete)):
+        guard let id = state.deletingProjectID else { return .none }
+        state.deletingProjectID = nil
+        return .run { [id] send in  // 캡처 리스트 명시
+          do {
+            try await sidebarClient.deleteProject(id)
+            await send(.deleteResponse(.success(id)))
+          } catch let error as SidebarError {
+            await send(.deleteResponse(.failure(error)))
+          } catch {
+            await send(.deleteResponse(.failure(.deleteFailed)))
+          }
+        }
+
+      case .alert:
+        return .none
+
+      case .deleteResponse(.success(let id)):
+        if state.selection == .project(id: id) {
+          state.selection = .filter(.all)
+        }
+        return .send(.task)
+
+      case .deleteResponse(.failure):
+        state.alert = makeDeleteFailedAlert()
+        return .none
+
       case .delegate:
         return .none
       }
     }
+    .ifLet(\.$alert, action: \.alert)
+  }
+}
+
+// MARK: - Private
+
+private extension SidebarFeature {
+
+  func makeDeleteAlert(for project: ProjectItem) -> AlertState<Action.Alert> {
+    AlertState {
+      TextState("'\(project.name)' 프로젝트를 삭제할까요?")
+    } actions: {
+      ButtonState(role: .destructive, action: .confirmDelete) {
+        TextState("삭제")
+      }
+      ButtonState(role: .cancel) {
+        TextState("취소")
+      }
+    } message: {
+      TextState("프로젝트에 속한 Secret과의 연결이 해제됩니다. Secret 자체는 삭제되지 않습니다.")
+    }
+  }
+
+  func makeRenameNameTakenAlert() -> AlertState<Action.Alert> {
+    AlertState {
+      TextState("이미 사용 중인 이름이에요")
+    } actions: {
+      ButtonState(role: .cancel) { TextState("확인") }
+    } message: {
+      TextState("다른 프로젝트 이름을 입력해주세요.")
+    }
+  }
+
+  func makeRenameFailedAlert() -> AlertState<Action.Alert> {
+    AlertState {
+      TextState("이름을 변경하지 못했어요")
+    } actions: {
+      ButtonState(role: .cancel) { TextState("확인") }
+    } message: {
+      TextState("잠시 후 다시 시도해주세요.")
+    }
+  }
+
+  func makeDeleteFailedAlert() -> AlertState<Action.Alert> {
+    AlertState {
+      TextState("프로젝트를 삭제하지 못했어요")
+    } actions: {
+      ButtonState(role: .cancel) { TextState("확인") }
+    } message: {
+      TextState("잠시 후 다시 시도해주세요.")
+    }
   }
 }
diff --git a/Projects/DVPresentation/Sources/Features/Sidebar/SidebarView.swift b/Projects/DVPresentation/Sources/Features/Sidebar/SidebarView.swift
index 610eb1f..dc5760e 100644
--- a/Projects/DVPresentation/Sources/Features/Sidebar/SidebarView.swift
+++ b/Projects/DVPresentation/Sources/Features/Sidebar/SidebarView.swift
@@ -12,12 +12,14 @@ struct SidebarView: View {
   // MARK: - Properties
 
   @Bindable var store: StoreOf<SidebarFeature>
+  @Environment(\.openWindow) private var openWindow
 
   // MARK: - Body
 
   var body: some View {
     content
       .task { store.send(.task) }
+      .alert($store.scope(state: \.alert, action: \.alert))
   }
 }
 
@@ -60,12 +62,12 @@ extension SidebarView {
         title: SidebarFilter.all.title,
         count: 0,
         systemImage: SidebarFilter.all.icon,
-        isSelected: store.selection == .filter(.all)
+        isSelected: !store.isCreatingSecret && store.selection == .filter(.all)
       ) {
         store.send(.didSelect(.filter(.all)))
       }
       .frame(height: 72)
-        
+
       LazyVGrid(
         columns: [GridItem(.flexible()), GridItem(.flexible())],
         spacing: 12
@@ -76,7 +78,7 @@ extension SidebarView {
             count: 0,
             systemImage: filter.icon,
             iconColor: filter.iconColor,
-            isSelected: store.selection == .filter(filter)
+            isSelected: !store.isCreatingSecret && store.selection == .filter(filter)
           ) {
             store.send(.didSelect(.filter(filter)))
           }
@@ -91,13 +93,33 @@ extension SidebarView {
       projectSectionHeader
         .padding(.horizontal, 8)
       if store.isProjectSectionExpanded {
-        projectList
+        projectSectionBody
       } else {
         Spacer(minLength: 0)
       }
     }
   }
 
+  @ViewBuilder
+  private var projectSectionBody: some View {
+    switch store.projectsState {
+    case .idle, .loading:
+      ProgressView()
+        .frame(maxWidth: .infinity)
+        .padding(.top, 8)
+      Spacer(minLength: 0)
+    case .loaded:
+      projectList
+    case .failed:
+      Text("불러오지 못했어요")
+        .dvFont(.bodyMD)
+        .foregroundStyle(Color.dv(.danger))
+        .frame(maxWidth: .infinity)
+        .padding(.top, 8)
+      Spacer(minLength: 0)
+    }
+  }
+
   private var projectSectionHeader: some View {
     HStack(spacing: 11) {
       Text("Project")
@@ -115,42 +137,68 @@ extension SidebarView {
     }
   }
 
-  // TODO: - contextMenu 확정 후 추후에 Action 추가
   private var projectList: some View {
-    let projects = ["Project A", "Project B", "Project C"]
-    // List(selection:)은 Int?를 요구하지만 store.selection은 SidebarSelection(enum)이라 타입 불일치로 $store 직접 바인딩 불가 → 의도적 manual Binding 사용
-    return List(
-      selection: Binding(
+    // List(selection:)은 ProjectItem.ID?를 요구하지만 store.selection은 SidebarSelection(enum)이라 타입 불일치로 $store 직접 바인딩 불가 → 의도적 manual Binding 사용
+    List(
+      selection: Binding<ProjectItem.ID?>(
         get: {
-          if case .project(let index) = store.selection { return index }
+          guard !store.isCreatingSecret else { return nil }
+          if case .project(id: let id) = store.selection { return id }
           return nil
         },
-        set: { index in
-          if let index { store.send(.didSelect(.project(index))) }
-          // TODO: nil(deselect) 처리 — content 컬럼 연결 시 결정
+        set: { id in
+          if let id { store.send(.didSelect(.project(id: id))) }
         }
       )
     ) {
-      ForEach(projects.indices, id: \.self) { index in
-        DVProjectContainer(name: projects[index], count: 0)
-          .tag(index)
+      ForEach(store.projects) { project in
+        projectRow(project)
+          .tag(project.id)
           .contextMenu {
-            Button("Rename") {}
-            Button("New Secret") {}
+            Button("Rename") { store.send(.didTapRename(id: project.id)) }
+            Button("New Secret") { store.send(.didTapAddButton) }
             Divider()
-            Button("Delete Project", role: .destructive) {}
+            Button("Delete Project", role: .destructive) {
+              store.send(.didTapDelete(id: project.id))
+            }
           }
       }
     }
     .listStyle(.sidebar)
     .scrollContentBackground(.hidden)
     .padding(.horizontal, -12)
+    .onKeyPress(.return) {
+      guard store.renamingProjectID == nil else { return .ignored }
+      if case .project(id: let id) = store.selection {
+        store.send(.didTapRename(id: id))
+        return .handled
+      }
+      return .ignored
+    }
+  }
+
+  @ViewBuilder
+  private func projectRow(_ project: ProjectItem) -> some View {
+    if store.renamingProjectID == project.id {
+      DVProjectRenameContainer(
+        text: Binding(
+          get: { store.renameText },
+          set: { store.send(.didChangeRenameText($0)) }
+        ),
+        onSubmit: { store.send(.didConfirmRename) },
+        onCancel: { store.send(.didCancelRename) }
+      )
+    } else {
+      DVProjectContainer(name: project.name, count: 0)
+    }
   }
 
   private var bottomBar: some View {
     HStack {
-      circleIconButton(icon: "gearshape") { store.send(.didTapSettingsButton) }
-        .accessibilityLabel("Settings")
+      circleIconButton(icon: "gearshape") {
+        openWindow(id: "settings")
+      }
+      .accessibilityLabel("Settings")
       Spacer()
       circleIconButton(icon: "plus") { store.send(.didTapAddButton) }
         .accessibilityLabel("Add Secret")
diff --git a/Projects/DVPresentation/Tests/CreateProject/CreateProjectFeatureTests.swift b/Projects/DVPresentation/Tests/CreateProject/CreateProjectFeatureTests.swift
index 9fbe207..e97c207 100644
--- a/Projects/DVPresentation/Tests/CreateProject/CreateProjectFeatureTests.swift
+++ b/Projects/DVPresentation/Tests/CreateProject/CreateProjectFeatureTests.swift
@@ -1,7 +1,6 @@
 // Copyright © 2026 Devault. All rights reserved
 
 import ComposableArchitecture
-import DVDomain
 import Foundation
 import Testing
 
@@ -11,80 +10,92 @@ import Testing
 @Suite("CreateProjectFeature")
 struct CreateProjectFeatureTests {
 
-    @Test("didTapCreate는 이름이 비어 있으면 아무 일도 안 한다")
-    func createIgnoresBlankName() async {
-        let store = TestStore(initialState: CreateProjectFeature.State()) {
-            CreateProjectFeature()
-        }
+  @Test("didTapCreate는 이름이 비어 있으면 아무 일도 안 한다")
+  func createIgnoresBlankName() async {
+    let store = TestStore(initialState: CreateProjectFeature.State()) {
+      CreateProjectFeature()
+    }
+
+    await store.send(.didChangeName("   ")) {
+      $0.name = "   "
+    }
+    await store.send(.didTapCreate)
+  }
 
-        await store.send(.didChangeName("   ")) {
-            $0.name = "   "
-        }
-        await store.send(.didTapCreate)
+  @Test("didTapCreate는 성공하면 delegate로 알리고 dismiss한다")
+  func createSucceedsAndDismisses() async {
+    let item = ProjectItem(id: UUID(), name: "DeVault")
+    var didDismiss = false
+    let store = TestStore(initialState: CreateProjectFeature.State()) {
+      CreateProjectFeature()
+    } withDependencies: {
+      $0.sidebarClient.createProject = { _ in item }
+      $0.dismiss = DismissEffect { didDismiss = true }
     }
 
-    @Test("didTapCreate는 성공하면 delegate로 알리고 dismiss한다")
-    func createSucceedsAndDismisses() async {
-        let project = Project(id: UUID(), name: "DeVault", createdAt: .now, updatedAt: .now)
-        var didDismiss = false
-        let store = TestStore(initialState: CreateProjectFeature.State()) {
-            CreateProjectFeature()
-        } withDependencies: {
-            $0.secretClient.createProject = { _ in project }
-            $0.dismiss = DismissEffect { didDismiss = true }
-        }
+    await store.send(.didChangeName("DeVault")) { $0.name = "DeVault" }
+    await store.send(.didTapCreate) { $0.isCreating = true }
+    await store.receive(.createResponse(.success(item))) { $0.isCreating = false }
+    await store.receive(.delegate(.projectCreated(item)))
 
-        await store.send(.didChangeName("DeVault")) {
-            $0.name = "DeVault"
-        }
-        await store.send(.didTapCreate) {
-            $0.isCreating = true
-        }
-        await store.receive(.createResponse(.success(project))) {
-            $0.isCreating = false
-        }
-        await store.receive(.delegate(.projectCreated(project)))
+    #expect(didDismiss)
+  }
 
-        #expect(didDismiss)
+  @Test("didTapCreate는 이름 중복 실패 시 nameTaken alert를 띄운다")
+  func createShowsNameTakenAlert() async {
+    let store = TestStore(initialState: CreateProjectFeature.State()) {
+      CreateProjectFeature()
+    } withDependencies: {
+      $0.sidebarClient.createProject = { _ in throw SidebarError.nameTaken }
     }
 
-    @Test("didTapCreate는 생성에 실패하면 alert를 띄우고 dismiss하지 않는다")
-    func createShowsAlertOnFailure() async {
-        let store = TestStore(initialState: CreateProjectFeature.State()) {
-            CreateProjectFeature()
-        } withDependencies: {
-            $0.secretClient.createProject = { _ in throw ProjectUseCaseError.unexpected }
-        }
-
-        await store.send(.didChangeName("DeVault")) {
-            $0.name = "DeVault"
-        }
-        await store.send(.didTapCreate) {
-            $0.isCreating = true
-        }
-        await store.receive(.createResponse(.failure(.unexpected))) {
-            $0.isCreating = false
-            $0.alert = AlertState {
-                TextState("프로젝트를 만들지 못했어요")
-            } actions: {
-                ButtonState(role: .cancel) { TextState("확인") }
-            } message: {
-                TextState("잠시 후 다시 시도해주세요.")
-            }
-        }
+    await store.send(.didChangeName("DeVault")) { $0.name = "DeVault" }
+    await store.send(.didTapCreate) { $0.isCreating = true }
+    await store.receive(.createResponse(.failure(.nameTaken))) {
+      $0.isCreating = false
+      $0.alert = AlertState {
+        TextState("이미 사용 중인 프로젝트 이름이에요")
+      } actions: {
+        ButtonState(role: .cancel) { TextState("확인") }
+      } message: {
+        TextState("다른 이름을 입력해주세요.")
+      }
     }
+  }
 
-    @Test("didTapCancel은 dismiss한다")
-    func cancelDismisses() async {
-        var didDismiss = false
-        let store = TestStore(initialState: CreateProjectFeature.State()) {
-            CreateProjectFeature()
-        } withDependencies: {
-            $0.dismiss = DismissEffect { didDismiss = true }
-        }
+  @Test("didTapCreate는 일반 실패 시 generic alert를 띄운다")
+  func createShowsGenericAlertOnFailure() async {
+    let store = TestStore(initialState: CreateProjectFeature.State()) {
+      CreateProjectFeature()
+    } withDependencies: {
+      $0.sidebarClient.createProject = { _ in throw SidebarError.createFailed }
+    }
 
-        await store.send(.didTapCancel)
+    await store.send(.didChangeName("DeVault")) { $0.name = "DeVault" }
+    await store.send(.didTapCreate) { $0.isCreating = true }
+    await store.receive(.createResponse(.failure(.createFailed))) {
+      $0.isCreating = false
+      $0.alert = AlertState {
+        TextState("프로젝트를 만들지 못했어요")
+      } actions: {
+        ButtonState(role: .cancel) { TextState("확인") }
+      } message: {
+        TextState("잠시 후 다시 시도해주세요.")
+      }
+    }
+  }
 
-        #expect(didDismiss)
+  @Test("didTapCancel은 dismiss한다")
+  func cancelDismisses() async {
+    var didDismiss = false
+    let store = TestStore(initialState: CreateProjectFeature.State()) {
+      CreateProjectFeature()
+    } withDependencies: {
+      $0.dismiss = DismissEffect { didDismiss = true }
     }
+
+    await store.send(.didTapCancel)
+
+    #expect(didDismiss)
+  }
 }
diff --git a/Projects/DVPresentation/Tests/Main/MainFeatureTests.swift b/Projects/DVPresentation/Tests/Main/MainFeatureTests.swift
new file mode 100644
index 0000000..5f5c411
--- /dev/null
+++ b/Projects/DVPresentation/Tests/Main/MainFeatureTests.swift
@@ -0,0 +1,182 @@
+// Copyright © 2026 Devault. All rights reserved
+
+import ComposableArchitecture
+import Foundation
+import Testing
+
+@testable import DVPresentation
+
+@MainActor
+@Suite("MainFeature")
+struct MainFeatureTests {
+
+  // MARK: - Sidebar Delegate
+
+  @Test("selectionChanged(.project)는 secretList를 해당 프로젝트로 갱신한다")
+  func selectionChangedUpdatesSecretList() async {
+    let item = ProjectItem(id: UUID(), name: "Backend")
+
+    var initial = MainFeature.State()
+    initial.sidebar.projectsState = .loaded([item])
+
+    let store = TestStore(initialState: initial) {
+      MainFeature()
+    }
+
+    await store.send(.sidebar(.didSelect(.project(id: item.id)))) {
+      $0.sidebar.selection = .project(id: item.id)
+    }
+    await store.receive(.sidebar(.delegate(.selectionChanged(.project(id: item.id))))) {
+      $0.secretList = SecretListFeature.State(
+        collection: .project(id: item.id),
+        projectName: "Backend"
+      )
+    }
+    await store.receive(.sidebar(.setCreatingSecret(false)))
+  }
+
+  @Test("selectionChanged는 selectSecretType을 닫고 isCreatingSecret을 false로 만든다")
+  func selectionChangedClosesSecretTypeSelection() async {
+    var initial = MainFeature.State()
+    initial.selectSecretType = .init()
+    initial.sidebar.isCreatingSecret = true
+
+    let store = TestStore(initialState: initial) {
+      MainFeature()
+    }
+
+    await store.send(.sidebar(.didSelect(.filter(.all)))) {
+      $0.sidebar.selection = .filter(.all)
+    }
+    await store.receive(.sidebar(.delegate(.selectionChanged(.filter(.all))))) {
+      $0.selectSecretType = nil
+      $0.secretList = SecretListFeature.State(collection: .all)
+    }
+    await store.receive(.sidebar(.setCreatingSecret(false))) {
+      $0.sidebar.isCreatingSecret = false
+    }
+  }
+
+  @Test("addButtonTapped은 selectSecretType을 열고 isCreatingSecret을 true로 만든다")
+  func addButtonTappedOpensSecretTypeSelection() async {
+    let store = TestStore(initialState: MainFeature.State()) {
+      MainFeature()
+    }
+
+    await store.send(.sidebar(.didTapAddButton))
+    await store.receive(.sidebar(.delegate(.addButtonTapped))) {
+      $0.selectSecretType = .init()
+    }
+    await store.receive(.sidebar(.setCreatingSecret(true))) {
+      $0.sidebar.isCreatingSecret = true
+    }
+  }
+
+  @Test("addProjectTapped은 createProject sheet를 연다")
+  func addProjectTappedOpensSheet() async {
+    let store = TestStore(initialState: MainFeature.State()) {
+      MainFeature()
+    }
+
+    await store.send(.sidebar(.didTapAddProject))
+    await store.receive(.sidebar(.delegate(.addProjectTapped))) {
+      $0.createProject = CreateProjectFeature.State()
+    }
+  }
+
+  // MARK: - CreateProject Delegate
+
+  @Test("projectCreated는 isCreatingSecret이 false일 때 selection을 새 프로젝트로 설정하고 refetch한다")
+  func projectCreatedSelectsNewProject() async {
+    let item = ProjectItem(id: UUID(), name: "Backend")
+
+    var initial = MainFeature.State()
+    initial.createProject = .init()
+    initial.sidebar.isCreatingSecret = false
+
+    let store = TestStore(initialState: initial) {
+      MainFeature()
+    } withDependencies: {
+      $0.sidebarClient.fetchProjects = { [item] }
+    }
+
+    await store.send(.createProject(.presented(.delegate(.projectCreated(item))))) {
+      $0.createProject = nil
+      $0.sidebar.selection = .project(id: item.id)
+      $0.secretList = SecretListFeature.State(
+        collection: .project(id: item.id),
+        projectName: "Backend"
+      )
+    }
+    await store.receive(.sidebar(.task)) {
+      $0.sidebar.projectsState = .loading
+    }
+    await store.receive(.sidebar(.projectsResponse(.success([item])))) {
+      $0.sidebar.projectsState = .loaded([item])
+    }
+  }
+
+  @Test("projectCreated는 isCreatingSecret이 true일 때 selection을 변경하지 않는다")
+  func projectCreatedDoesNotSelectWhenCreatingSecret() async {
+    let item = ProjectItem(id: UUID(), name: "Backend")
+
+    var initial = MainFeature.State()
+    initial.createProject = .init()
+    initial.sidebar.isCreatingSecret = true
+
+    let store = TestStore(initialState: initial) {
+      MainFeature()
+    } withDependencies: {
+      $0.sidebarClient.fetchProjects = { [item] }
+    }
+
+    await store.send(.createProject(.presented(.delegate(.projectCreated(item))))) {
+      $0.createProject = nil
+      // selection 및 secretList 변경 없음
+    }
+    await store.receive(.sidebar(.task)) {
+      $0.sidebar.projectsState = .loading
+    }
+    await store.receive(.sidebar(.projectsResponse(.success([item])))) {
+      $0.sidebar.projectsState = .loaded([item])
+    }
+  }
+
+  // MARK: - Rename Delegate
+
+  @Test("projectRenamed는 현재 선택된 프로젝트의 이름이면 secretList 타이틀을 갱신한다")
+  func projectRenamedUpdatesSecretListTitle() async {
+    let item = ProjectItem(id: UUID(), name: "Backend")
+    let renamed = ProjectItem(id: item.id, name: "Backend V2")
+
+    var initial = MainFeature.State()
+    initial.sidebar.projectsState = .loaded([item])
+    initial.sidebar.selection = .project(id: item.id)
+    initial.secretList = SecretListFeature.State(
+      collection: .project(id: item.id),
+      projectName: "Backend"
+    )
+
+    let store = TestStore(initialState: initial) {
+      MainFeature()
+    } withDependencies: {
+      $0.sidebarClient.fetchProjects = { [renamed] }
+    }
+
+    await store.send(.sidebar(.renameResponse(.success(renamed))))
+    // delegate payload의 이름을 직접 사용해 즉시 갱신
+    await store.receive(.sidebar(.delegate(.projectRenamed(renamed)))) {
+      $0.secretList = SecretListFeature.State(
+        collection: .project(id: item.id),
+        projectName: "Backend V2"
+      )
+    }
+    // 이후 refetch로 목록도 동기화
+    await store.receive(.sidebar(.task)) {
+      $0.sidebar.projectsState = .loading
+    }
+    await store.receive(.sidebar(.projectsResponse(.success([renamed])))) {
+      $0.sidebar.projectsState = .loaded([renamed])
+    }
+  }
+}
diff --git a/Projects/DVPresentation/Tests/Sidebar/SidebarFeatureTests.swift b/Projects/DVPresentation/Tests/Sidebar/SidebarFeatureTests.swift
new file mode 100644
index 0000000..702ab60
--- /dev/null
+++ b/Projects/DVPresentation/Tests/Sidebar/SidebarFeatureTests.swift
@@ -0,0 +1,219 @@
+// Copyright © 2026 Devault. All rights reserved
+
+import ComposableArchitecture
+import Foundation
+import Testing
+
+@testable import DVPresentation
+
+@MainActor
+@Suite("SidebarFeature")
+struct SidebarFeatureTests {
+
+  // MARK: - Fetch
+
+  @Test("task는 프로젝트 목록을 fetch해 이름 순으로 정렬한다")
+  func taskFetchesSortedProjects() async {
+    let projects = [
+      ProjectItem(id: UUID(), name: "Mobile"),
+      ProjectItem(id: UUID(), name: "Backend"),
+    ]
+    let store = TestStore(initialState: SidebarFeature.State()) {
+      SidebarFeature()
+    } withDependencies: {
+      $0.sidebarClient.fetchProjects = { projects }
+    }
+
+    await store.send(.task) {
+      $0.projectsState = .loading
+    }
+    await store.receive(.projectsResponse(.success(projects))) {
+      $0.projectsState = .loaded(IdentifiedArray(uniqueElements: [
+        ProjectItem(id: projects[1].id, name: "Backend"),
+        ProjectItem(id: projects[0].id, name: "Mobile"),
+      ]))
+    }
+  }
+
+  @Test("task fetch 실패 시 projectsState가 .failed로 전환된다")
+  func taskFetchFailureSetsFailedState() async {
+    let store = TestStore(initialState: SidebarFeature.State()) {
+      SidebarFeature()
+    } withDependencies: {
+      $0.sidebarClient.fetchProjects = { throw SidebarError.fetchFailed }
+    }
+
+    await store.send(.task) {
+      $0.projectsState = .loading
+    }
+    await store.receive(.projectsResponse(.failure(.fetchFailed))) {
+      $0.projectsState = .failed(.fetchFailed)
+    }
+  }
+
+  // MARK: - Selection
+
+  @Test("didSelect는 selection을 바꾸고 delegate를 발송한다")
+  func didSelectChangesSelectionAndSendsDelegate() async {
+    let id = UUID()
+    let store = TestStore(
+      initialState: SidebarFeature.State()
+    ) {
+      SidebarFeature()
+    }
+
+    await store.send(.didSelect(.project(id: id))) {
+      $0.selection = .project(id: id)
+    }
+    await store.receive(.delegate(.selectionChanged(.project(id: id))))
+  }
+
+  // MARK: - Rename
+
+  @Test("didTapRename은 renameText를 프로젝트 이름으로 세팅한다")
+  func didTapRenameSetRenameText() async {
+    let item = ProjectItem(id: UUID(), name: "Backend")
+    var state = SidebarFeature.State()
+    state.projectsState = .loaded([item])
+
+    let store = TestStore(initialState: state) {
+      SidebarFeature()
+    }
+
+    await store.send(.didTapRename(id: item.id)) {
+      $0.renamingProjectID = item.id
+      $0.renameText = "Backend"
+    }
+  }
+
+  @Test("didConfirmRename 성공 시 delegate를 발송하고 refetch한다")
+  func didConfirmRenameSuccessDelegate() async {
+    let item = ProjectItem(id: UUID(), name: "Backend")
+    let renamed = ProjectItem(id: item.id, name: "Backend V2")
+
+    var state = SidebarFeature.State()
+    state.projectsState = .loaded([item])
+    state.renamingProjectID = item.id
+    state.renameText = "Backend V2"
+
+    let store = TestStore(initialState: state) {
+      SidebarFeature()
+    } withDependencies: {
+      $0.sidebarClient.renameProject = { _, _ in renamed }
+      $0.sidebarClient.fetchProjects = { [renamed] }
+    }
+
+    await store.send(.didConfirmRename) {
+      $0.renamingProjectID = nil
+      $0.renameText = ""
+    }
+    await store.receive(.renameResponse(.success(renamed)))
+    await store.receive(.delegate(.projectRenamed(renamed)))
+    await store.receive(.task) {
+      $0.projectsState = .loading
+    }
+    await store.receive(.projectsResponse(.success([renamed]))) {
+      $0.projectsState = .loaded([renamed])
+    }
+  }
+
+  @Test("didConfirmRename에서 nameTaken 오류 시 alert가 표시된다")
+  func didConfirmRenameNameTakenShowsAlert() async {
+    let item = ProjectItem(id: UUID(), name: "Backend")
+    var state = SidebarFeature.State()
+    state.projectsState = .loaded([item])
+    state.renamingProjectID = item.id
+    state.renameText = "Mobile"
+
+    let store = TestStore(initialState: state) {
+      SidebarFeature()
+    } withDependencies: {
+      $0.sidebarClient.renameProject = { _, _ in throw SidebarError.nameTaken }
+    }
+
+    await store.send(.didConfirmRename) {
+      $0.renamingProjectID = nil
+      $0.renameText = ""
+    }
+    await store.receive(.renameResponse(.failure(.nameTaken))) {
+      $0.alert = AlertState {
+        TextState("이미 사용 중인 이름이에요")
+      } actions: {
+        ButtonState(role: .cancel) { TextState("확인") }
+      } message: {
+        TextState("다른 프로젝트 이름을 입력해주세요.")
+      }
+    }
+  }
+
+  @Test("didCancelRename은 rename 상태를 초기화한다")
+  func didCancelRenameResetsState() async {
+    var state = SidebarFeature.State()
+    state.renamingProjectID = UUID()
+    state.renameText = "Some Name"
+
+    let store = TestStore(initialState: state) {
+      SidebarFeature()
+    }
+
+    await store.send(.didCancelRename) {
+      $0.renamingProjectID = nil
+      $0.renameText = ""
+    }
+  }
+
+  // MARK: - Delete
+
+  @Test("didTapDelete는 alert를 표시한다")
+  func didTapDeleteShowsAlert() async {
+    let item = ProjectItem(id: UUID(), name: "Backend")
+    var state = SidebarFeature.State()
+    state.projectsState = .loaded([item])
+
+    let store = TestStore(initialState: state) {
+      SidebarFeature()
+    }
+
+    await store.send(.didTapDelete(id: item.id)) {
+      $0.deletingProjectID = item.id
+      $0.alert = AlertState {
+        TextState("'\(item.name)' 프로젝트를 삭제할까요?")
+      } actions: {
+        ButtonState(role: .destructive, action: .confirmDelete) { TextState("삭제") }
+        ButtonState(role: .cancel) { TextState("취소") }
+      } message: {
+        TextState("프로젝트에 속한 Secret과의 연결이 해제됩니다. Secret 자체는 삭제되지 않습니다.")
+      }
+    }
+  }
+
+  @Test("삭제 확인 후 선택 중이던 프로젝트면 selection이 .all로 초기화되고 refetch한다")
+  func deleteResetsSelectionAndRefetches() async {
+    let item = ProjectItem(id: UUID(), name: "Backend")
+
+    var state = SidebarFeature.State()
+    state.projectsState = .loaded([item])
+    state.selection = .project(id: item.id)
+    state.deletingProjectID = item.id
+
+    let store = TestStore(initialState: state) {
+      SidebarFeature()
+    } withDependencies: {
+      $0.sidebarClient.deleteProject = { _ in }
+      $0.sidebarClient.fetchProjects = { [] }
+    }
+
+    await store.send(.alert(.presented(.confirmDelete))) {
+      $0.deletingProjectID = nil
+    }
+    await store.receive(.deleteResponse(.success(item.id))) {
+      $0.selection = .filter(.all)
+    }
+    await store.receive(.task) {
+      $0.projectsState = .loading
+    }
+    await store.receive(.projectsResponse(.success([]))) {
+      $0.projectsState = .loaded([])
+    }
+  }
+}
diff --git a/Projects/Devault/Sources/Composition/Dependencies/SidebarClient+Live.swift b/Projects/Devault/Sources/Composition/Dependencies/SidebarClient+Live.swift
new file mode 100644
index 0000000..bb31a94
--- /dev/null
+++ b/Projects/Devault/Sources/Composition/Dependencies/SidebarClient+Live.swift
@@ -0,0 +1,55 @@
+// Copyright © 2026 Devault. All rights reserved
+
+import ComposableArchitecture
+import DVData
+import DVDomain
+import DVPresentation
+
+extension SidebarClient: @retroactive DependencyKey {
+  public static let liveValue: SidebarClient = {
+    let container = LiveStorage.shared.modelContainer
+    let repo: any ProjectRepository = ProjectRepositoryImpl(modelContainer: container)
+
+    let fetchUseCase: any FetchProjectUseCase = FetchProjectUseCaseImpl(repository: repo)
+    let createUseCase: any CreateProjectUseCase = CreateProjectUseCaseImpl(repository: repo)
+    let renameUseCase: any RenameProjectUseCase = RenameProjectUseCaseImpl(repository: repo)
+    let deleteUseCase: any DeleteProjectUseCase = DeleteProjectUseCaseImpl(repository: repo)
+
+    return SidebarClient(
+      fetchProjects: {
+        do {
+          return try await fetchUseCase.fetchAll().map(ProjectItem.init)
+        } catch {
+          throw SidebarError.fetchFailed
+        }
+      },
+      createProject: { name in
+        do {
+          return try await ProjectItem(createUseCase.execute(name: name))
+        } catch let error as ProjectUseCaseError {
+          if case .repositoryFailure(.duplicateName) = error { throw SidebarError.nameTaken }
+          throw SidebarError.createFailed
+        } catch {
+          throw SidebarError.createFailed
+        }
+      },
+      renameProject: { id, name in
+        do {
+          return try await ProjectItem(renameUseCase.rename(id: id, name: name))
+        } catch let error as ProjectUseCaseError {
+          if case .repositoryFailure(.duplicateName) = error { throw SidebarError.nameTaken }
+          throw SidebarError.renameFailed
+        } catch {
+          throw SidebarError.renameFailed
+        }
+      },
+      deleteProject: { id in
+        do {
+          try await deleteUseCase.delete(id: id)
+        } catch {
+          throw SidebarError.deleteFailed
+        }
+      }
+    )
+  }()
+}
diff --git a/Projects/Devault/Sources/Composition/LiveStorage.swift b/Projects/Devault/Sources/Composition/LiveStorage.swift
new file mode 100644
index 0000000..87f09cd
--- /dev/null
+++ b/Projects/Devault/Sources/Composition/LiveStorage.swift
@@ -0,0 +1,19 @@
+// Copyright © 2026 Devault. All rights reserved
+
+import OSLog
+import DVData
+
+/// Composition Root에서 공유하는 ModelContainer 단일 인스턴스.
+/// SecretRepositoryImpl, ProjectRepositoryImpl이 동일 컨테이너를 참조해야 한다.
+enum LiveStorage {
+  private static let logger = Logger(subsystem: "com.devault", category: "LiveStorage")
+
+  static let shared: LocalStorage = {
+    do {
+      return try LocalStorage.makeDefault()
+    } catch {
+      logger.critical("LocalStorage 초기화 실패: \(error, privacy: .public)")
+      fatalError("LocalStorage 초기화 실패 — 앱을 재시작하거나 데이터를 복원하세요.\n\(error)")
+    }
+  }()
+}
diff --git a/Projects/Devault/Sources/DevaultApp.swift b/Projects/Devault/Sources/DevaultApp.swift
index 8106549..76e676a 100644
--- a/Projects/Devault/Sources/DevaultApp.swift
+++ b/Projects/Devault/Sources/DevaultApp.swift
@@ -16,5 +16,11 @@ struct DevaultApp: App {
     }
     .windowStyle(.hiddenTitleBar)
     .defaultSize(width: 800, height: 600)
+
+    WindowGroup("Settings", id: "settings") {
+      Text("Settings")
+        .frame(width: 500, height: 400)
+    }
+    .defaultSize(width: 500, height: 400)
   }
 }