diff --git a/.claude/agents/change-reviewer.md b/.claude/agents/change-reviewer.md
index 9f3c8142..9ca6f3f3 100644
--- a/.claude/agents/change-reviewer.md
+++ b/.claude/agents/change-reviewer.md
@@ -14,10 +14,11 @@ Review all recent code changes thoroughly and provide a structured, actionable a
 
 ## Project Context
 
-- **Branch**: feature/navigation-stack — Pure SwiftUI, NavigationPath, single AppCoordinator (ObservableObject), Combine
+- **Branch**: feature/observation — Pure SwiftUI, @Observable, AsyncSequence + StreamBroadcaster, zero Combine
 - **Packages**: `FunCore` → `FunModel` → `FunViewModel` / `FunServices` → `FunUI` → `FunCoordinator`
 - **Dependency direction**: Never import upward. ViewModel must NOT import UI or Coordinator.
 - **UIKit**: Zero UIKit in this branch — flag any `import UIKit` as a critical issue
+- **Combine**: Zero Combine in this branch — flag any `import Combine` as critical
 - **DI**: ServiceLocator with `@Service` property wrapper, session-scoped (LoginSession / AuthenticatedSession)
 - **Testing**: Swift Testing framework, mocks in FunModelTestSupport
 - **Lint**: SwiftLint with custom rules (no_print, weak_coordinator_in_viewmodel, no_direct_userdefaults)
@@ -38,19 +39,23 @@ Review all recent code changes thoroughly and provide a structured, actionable a
 ### Step 3: Architecture Check
 - Package dependency direction respected?
 - No `import UIKit` — pure SwiftUI branch
+- No `import Combine` — pure AsyncSequence branch
 - No coordinator references in ViewModels (except weak closures)
 - No `print()` — use LoggerService
 - No `UserDefaults.standard` outside Services
 - Navigation logic only in Coordinators (AppCoordinator)
 - NavigationPath mutations only in coordinator, not in Views
 - Protocols in Core (reusable) or Model (domain), never in Services/ViewModel/UI/Coordinator
-- Reactive pattern: Combine (`@Published`, `@StateObject`, `@ObservedObject`, `.sink`)
+- Reactive pattern: `@Observable`, `AsyncStream`, `StreamBroadcaster`, `for await`, `Task`
+- `@ObservationIgnored` on services and non-UI state
+- `@State` (not `@StateObject`) for owning @Observable objects
 
 ### Step 4: Correctness Check
 - **Logic errors**: Algorithms, conditions, control flow
 - **Type safety**: Force unwraps, force casts, unsafe assumptions
 - **Concurrency**: `@MainActor` isolation, `Sendable` conformance, Swift 6 strict
-- **Memory management**: `[weak self]` and `[weak coordinator]` in closures
+- **Memory management**: `[weak self]` and `[weak coordinator]` in closures, `guard let self` inside `for await` loops
+- **Stream lifecycle**: Tasks stored for cancellation? Cleaned up properly?
 - **API contracts**: Public interfaces used correctly
 
 ### Step 5: Quality Check
diff --git a/.claude/skills/pull-request/SKILL.md b/.claude/skills/pull-request/SKILL.md
index cffd7b97..af07a2bc 100644
--- a/.claude/skills/pull-request/SKILL.md
+++ b/.claude/skills/pull-request/SKILL.md
@@ -18,8 +18,7 @@ Create a draft PR following the team's quality standards.
 2. **Review changes**
    - `git diff main...HEAD` to review all changes
    - Verify package dependency direction isn't violated
-   - Check for any `print()`, `UserDefaults.standard`, or other anti-patterns
-   - Verify zero UIKit imports (this branch is pure SwiftUI)
+   - Check for any `print()`, `UserDefaults.standard`, `import Combine`, or `import UIKit`
 
 3. **Accessibility checklist** (for UI changes)
    - Dynamic Type: Do text elements scale with user font size preference?
diff --git a/.claude/skills/review/SKILL.md b/.claude/skills/review/SKILL.md
index 826c8c4a..cb024555 100644
--- a/.claude/skills/review/SKILL.md
+++ b/.claude/skills/review/SKILL.md
@@ -21,12 +21,13 @@ Review all recent code changes for completeness, correctness, and consistency wi
 3. **Architecture check**
    - Verify package dependency direction: `Coordinator → UI → ViewModel → Model → Core`, `Services → Model → Core`
    - No `import UIKit` anywhere — this branch is pure SwiftUI
+   - No `import Combine` anywhere — this branch uses AsyncSequence, zero Combine
    - No coordinator references in ViewModels (except weak closures)
    - No `print()` — use LoggerService
    - No `UserDefaults.standard` outside Services
    - Navigation logic only in Coordinators
    - Protocols in Core (reusable) or Model (domain), never in Services/ViewModel/UI/Coordinator
-   - Branch-specific: Combine + NavigationPath + single AppCoordinator (ObservableObject)
+   - Branch-specific: @Observable + AsyncStream + StreamBroadcaster (no Combine, no ObservableObject)
 
 4. **Similar pattern search**
    - Search the codebase for code that follows the same pattern as what changed
@@ -35,6 +36,7 @@ Review all recent code changes for completeness, correctness, and consistency wi
 5. **Correctness check**
    - Logic errors, type safety, concurrency (Swift 6 strict), memory management (`[weak self]`, `[weak coordinator]`)
    - Verify `@MainActor` isolation, `Sendable` conformance where needed
+   - Check `@ObservationIgnored` on properties that shouldn't trigger view updates
 
 6. **Cross-platform parity**
    - Compare with `~/Documents/Source/Fun-Android/` for the same feature
diff --git a/CLAUDE.md b/CLAUDE.md
index ef58e585..2d9d026a 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -46,42 +46,43 @@ Never import upward. ViewModel must NOT import UI or Coordinator. Model must NOT
 
 ## Anti-Patterns (Red Flags)
 - `import UIKit` anywhere — this branch is pure SwiftUI, zero UIKit
+- `import Combine` anywhere — this branch uses AsyncSequence, zero Combine
 - Coordinator references in ViewModels (except weak optional closures) — retain cycle risk
 - `print()` anywhere — use LoggerService
 - `UserDefaults.standard` outside Services — use FeatureToggleService
 - Adding `fatalError()` for missing services — ServiceLocator.resolve() already crashes with `fatalError` if a service isn't registered; don't add redundant guards
 - Navigation logic in Views — all navigation (push, pop, tab switch, modal present/dismiss) must go through named AppCoordinator methods (`showDetail`, `selectTab`, `showProfile`, etc.), never inline property manipulation like `coordinator.homePath.append(item)` or `coordinator.isProfilePresented = true`
 - Protocol definitions in Services — domain protocols go in Model, reusable abstractions in Core
-- Wrong ownership annotations — tab content wrappers must use `@StateObject` to own ViewModels (not `@ObservedObject`). `@ObservedObject` on a ViewModel means it gets recreated on every re-render. Conversely, the coordinator must be `let` or `@ObservedObject` (not `@StateObject`) since the wrapper doesn't own it.
+- Wrong ownership annotations — tab content wrappers must use `@State` to own ViewModels (not bare `var`). `@State` ensures the ViewModel survives re-renders. The coordinator must be `let` (not `@Bindable` or `@State`) since the wrapper doesn't own it.
 
-## Architecture (this branch: feature/navigation-stack)
+## Architecture (this branch: feature/observation)
 - **Entry point**: SwiftUI `@main App` struct (`FunApp.swift`) — no AppDelegate or SceneDelegate
-- **Navigation**: Single `AppCoordinator: ObservableObject` with per-tab `NavigationPath`
+- **Navigation**: Single `@Observable AppCoordinator` with per-tab `NavigationPath`
 - **Views**: Pure SwiftUI views, no UIHostingController or UIViewControllers
-- **Reactive**: Combine (`@Published`, `@StateObject`, `@ObservedObject`, `.sink`)
+- **Reactive**: AsyncSequence + `StreamBroadcaster` (zero Combine). Services yield events via `StreamBroadcaster.yield()`, consumers iterate with `for await event in stream`
+- **Observation**: `@Observable` (not ObservableObject), `@ObservationIgnored` for non-observed state, `@State` (not @StateObject) in app entry
 - **ViewModel → Coordinator**: Optional closures wired in tab content wrappers via `.task { viewModel.onShowDetail = { ... } }`
 - **Tab bar**: SwiftUI `TabView(selection: $coordinator.selectedTab)`
 - **Push nav**: `coordinator.showDetail(item, in: .home)` — named methods on AppCoordinator
 - **Modals**: `.sheet(isPresented: $coordinator.isProfilePresented)`
 - **DI**: ServiceLocator with `@Service` property wrapper, session-scoped (LoginSession / AuthenticatedSession)
 - **Coordinator-owned views**: `AppRootView`, `MainTabView`, and tab content wrappers live in `Coordinator` (not `FunUI`) because they depend on `AppCoordinator`. Moving them to `FunUI` would create a circular dependency (`Coordinator → UI → Coordinator`). Pure reusable views (`HomeView`, `DetailView`, etc.) stay in `FunUI`.
-- **Ownership wrappers**: Tab content wrappers (`HomeTabContent`, `ItemsTabContent`, etc.) use `@StateObject` to **own** their ViewModel and `@ObservedObject` (or `let`) for the coordinator passed from the parent. `@StateObject` ensures the ViewModel survives re-renders; `@ObservedObject` means the wrapper doesn't own the coordinator. Pure views in `FunUI` take `@ObservedObject var viewModel` since the wrapper owns it.
+- **Ownership wrappers**: Tab content wrappers (`HomeTabContent`, `ItemsTabContent`, etc.) use `@State` to **own** their ViewModel and `let` for the coordinator passed from the parent. `@State` ensures the ViewModel survives re-renders; `let` means the wrapper doesn't own the coordinator. Pure views in `FunUI` take the ViewModel as a parameter since the wrapper owns it.
 
 ## Rule Index
 Consult these files for detailed guidance (not auto-loaded — read on demand):
 - `ai-rules/general.md` — Architecture deep-dive, MVVM-C patterns, DI, sessions, testing
-- `ai-rules/swift-style.md` — Swift 6 concurrency, naming, Combine patterns, SwiftLint rules
+- `ai-rules/swift-style.md` — Swift 6 concurrency, naming, AsyncSequence patterns, SwiftLint rules
 - `ai-rules/ci-cd.md` — GitHub Actions CI workflow patterns
 
 ## Code Style
 - Swift 6 strict concurrency, iOS 17+
-- Pure SwiftUI (NavigationStack), MVVM-C with Combine
-- Single AppCoordinator: ObservableObject with @Published NavigationPath per tab
-- ViewModels use closures for navigation, wired in tab content wrappers
+- Pure SwiftUI (NavigationStack), MVVM-C with AsyncSequence + @Observable
+- Zero Combine — AsyncStream + StreamBroadcaster for reactive service events, @Observable for ViewModel state
+- Navigation closures on ViewModels, wired by single AppCoordinator
 - Navigation logic ONLY in Coordinators, never in Views
 - Protocol placement: Core = reusable abstractions, Model = domain-specific
-- ServiceLocator with @Service property wrapper
-- Combine over NotificationCenter for reactive state
+- ServiceLocator with @Service property wrapper (assertionFailure, not fatalError)
 
 ## Testing
 - Swift Testing framework (`import Testing`, `@Test`, `#expect`, `@Suite`)
diff --git a/Coordinator/Package.swift b/Coordinator/Package.swift
index a01b355c..aa0abaa2 100644
--- a/Coordinator/Package.swift
+++ b/Coordinator/Package.swift
@@ -4,8 +4,8 @@ import PackageDescription
 let package = Package(
     name: "Coordinator",
     platforms: [
-        .iOS(.v16),
-        .macCatalyst(.v16),
+        .iOS(.v17),
+        .macCatalyst(.v17),
     ],
     products: [
         .library(name: "FunCoordinator", targets: ["FunCoordinator"]),
diff --git a/Coordinator/Sources/Coordinator/AppCoordinator.swift b/Coordinator/Sources/Coordinator/AppCoordinator.swift
index 7a280dab..e14c8f64 100644
--- a/Coordinator/Sources/Coordinator/AppCoordinator.swift
+++ b/Coordinator/Sources/Coordinator/AppCoordinator.swift
@@ -5,51 +5,56 @@
 //  SwiftUI-based coordinator managing navigation state and app flow
 //
 
-import Combine
+import Observation
 import SwiftUI
 
 import FunCore
 import FunModel
 
 @MainActor
-public final class AppCoordinator: ObservableObject {
+@Observable
+public final class AppCoordinator {
 
     // MARK: - Services
 
-    @Service(.logger) private var logger: LoggerService
-    @Service(.featureToggles) private var featureToggleService: FeatureToggleServiceProtocol
-    @Service(.toast) private var toastService: ToastServiceProtocol
+    @ObservationIgnored @Service(.logger) private var logger: LoggerService
+    @ObservationIgnored @Service(.featureToggles) private var featureToggleService: FeatureToggleServiceProtocol
+    @ObservationIgnored @Service(.toast) private var toastService: ToastServiceProtocol
 
     // MARK: - Session Management
 
-    private let sessionFactory: SessionFactory
-    private var currentSession: Session?
+    @ObservationIgnored private let sessionFactory: SessionFactory
+    @ObservationIgnored private var currentSession: Session?
 
     // MARK: - App Flow State
 
-    @Published public var currentFlow: AppFlow = .login
+    public var currentFlow: AppFlow = .login
 
     // MARK: - Navigation State
 
-    @Published public var selectedTab: TabIndex = .home
-    @Published public var homePath = NavigationPath()
-    @Published public var itemsPath = NavigationPath()
-    @Published public var settingsPath = NavigationPath()
-    @Published public var isProfilePresented = false
+    public var selectedTab: TabIndex = .home
+    public var homePath = NavigationPath()
+    public var itemsPath = NavigationPath()
+    public var settingsPath = NavigationPath()
+    public var isProfilePresented = false
 
     // MARK: - Deep Link
 
-    private var pendingDeepLink: DeepLink?
+    @ObservationIgnored private var pendingDeepLink: DeepLink?
+
+    // MARK: - Service Observation
+
+    @ObservationIgnored private var registrationObservation: Task<Void, Never>?
+    @ObservationIgnored private var toastObservation: Task<Void, Never>?
+    @ObservationIgnored private var darkModeObservation: Task<Void, Never>?
 
     // MARK: - Toast
 
-    @Published public var activeToast: ToastEvent?
-    private var cancellables = Set<AnyCancellable>()
+    public var activeToast: ToastEvent?
 
     // MARK: - Dark Mode
 
-    @Published public var appearanceMode: AppearanceMode = .system
-    private var darkModeCancellable: AnyCancellable?
+    public var appearanceMode: AppearanceMode = .system
 
     // MARK: - Init
 
@@ -57,12 +62,17 @@ public final class AppCoordinator: ObservableObject {
         self.sessionFactory = sessionFactory
     }
 
+    deinit {
+        registrationObservation?.cancel()
+        toastObservation?.cancel()
+        darkModeObservation?.cancel()
+    }
+
     // MARK: - Start
 
     public func start() {
         activateSession(for: currentFlow)
-        observeToastEvents()
-        observeDarkMode()
+        observeServiceRegistrations()
     }
 
     // MARK: - Session Lifecycle
@@ -171,23 +181,34 @@ public final class AppCoordinator: ObservableObject {
         }
     }
 
-    // MARK: - Toast
+    // MARK: - Service Registration Observation
 
-    private func observeToastEvents() {
-        ServiceLocator.shared.serviceDidRegisterPublisher
-            .filter { $0 == .toast }
-            .sink { [weak self] _ in
-                self?.subscribeToToasts()
+    private func observeServiceRegistrations() {
+        registrationObservation?.cancel()
+        let registrations = ServiceLocator.shared.serviceRegistrations
+        registrationObservation = Task { [weak self] in
+            for await key in registrations {
+                guard let self else { break }
+                switch key {
+                case .toast: self.subscribeToToasts()
+                case .featureToggles: self.subscribeToDarkMode()
+                default: break
+                }
             }
-            .store(in: &cancellables)
+        }
     }
 
+    // MARK: - Toast
+
     private func subscribeToToasts() {
-        toastService.toastPublisher
-            .sink { [weak self] event in
-                self?.activeToast = event
+        toastObservation?.cancel()
+        let stream = toastService.toastStream
+        toastObservation = Task { [weak self] in
+            for await event in stream {
+                guard let self else { break }
+                self.activeToast = event
             }
-            .store(in: &cancellables)
+        }
     }
 
     public func dismissToast() {
@@ -196,20 +217,15 @@ public final class AppCoordinator: ObservableObject {
 
     // MARK: - Dark Mode Observation
 
-    private func observeDarkMode() {
-        ServiceLocator.shared.serviceDidRegisterPublisher
-            .filter { $0 == .featureToggles }
-            .sink { [weak self] _ in
-                self?.subscribeToDarkMode()
-            }
-            .store(in: &cancellables)
-    }
-
     private func subscribeToDarkMode() {
-        darkModeCancellable?.cancel()
-        darkModeCancellable = featureToggleService.appearanceModePublisher
-            .sink { [weak self] mode in
-                self?.appearanceMode = mode
+        darkModeObservation?.cancel()
+        appearanceMode = featureToggleService.appearanceMode
+        let stream = featureToggleService.appearanceModeStream
+        darkModeObservation = Task { [weak self] in
+            for await mode in stream {
+                guard let self else { break }
+                self.appearanceMode = mode
             }
+        }
     }
 }
diff --git a/Coordinator/Sources/Coordinator/AppRootView.swift b/Coordinator/Sources/Coordinator/AppRootView.swift
index a15b2113..f7077ac9 100644
--- a/Coordinator/Sources/Coordinator/AppRootView.swift
+++ b/Coordinator/Sources/Coordinator/AppRootView.swift
@@ -15,7 +15,8 @@ import FunUI
 import FunViewModel
 
 public struct AppRootView: View {
-    @ObservedObject var coordinator: AppCoordinator
+    // Plain var — only reads coordinator properties, no $ bindings needed
+    var coordinator: AppCoordinator
 
     public init(coordinator: AppCoordinator) {
         self.coordinator = coordinator
diff --git a/Coordinator/Sources/Coordinator/MainTabView.swift b/Coordinator/Sources/Coordinator/MainTabView.swift
index 8bfde47d..e4af055e 100644
--- a/Coordinator/Sources/Coordinator/MainTabView.swift
+++ b/Coordinator/Sources/Coordinator/MainTabView.swift
@@ -15,7 +15,8 @@ import FunUI
 import FunViewModel
 
 struct MainTabView: View {
-    @ObservedObject var coordinator: AppCoordinator
+    // @Bindable — needs $ bindings for TabView selection, NavigationStack paths, .sheet
+    @Bindable var coordinator: AppCoordinator
 
     var body: some View {
         TabView(selection: $coordinator.selectedTab) {
@@ -47,7 +48,6 @@ struct MainTabView: View {
                 .navigationDestination(for: FeaturedItem.self) { item in
                     coordinator.destinationView(for: item)
                 }
-                // Chain more .navigationDestination(for:) to handle additional pushable types.
         }
         .tabItem {
             Label(L10n.Tabs.home, systemImage: "house")
@@ -62,7 +62,6 @@ struct MainTabView: View {
                 .navigationDestination(for: FeaturedItem.self) { item in
                     coordinator.destinationView(for: item)
                 }
-                // Chain more .navigationDestination(for:) to handle additional pushable types.
         }
         .tabItem {
             Label(L10n.Tabs.items, systemImage: "list.bullet")
@@ -88,7 +87,7 @@ struct MainTabView: View {
 /// Wrapper that creates HomeViewModel with navigation closures wired to coordinator
 struct HomeTabContent: View {
     let coordinator: AppCoordinator
-    @StateObject private var viewModel = HomeViewModel()
+    @State private var viewModel = HomeViewModel()
 
     var body: some View {
         HomeView(viewModel: viewModel)
@@ -106,7 +105,7 @@ struct HomeTabContent: View {
 /// Wrapper that creates ItemsViewModel with navigation closures wired to coordinator
 struct ItemsTabContent: View {
     let coordinator: AppCoordinator
-    @StateObject private var viewModel = ItemsViewModel()
+    @State private var viewModel = ItemsViewModel()
 
     var body: some View {
         ItemsView(viewModel: viewModel)
@@ -120,7 +119,7 @@ struct ItemsTabContent: View {
 
 /// Wrapper that creates SettingsViewModel
 struct SettingsTabContent: View {
-    @StateObject private var viewModel = SettingsViewModel()
+    @State private var viewModel = SettingsViewModel()
 
     var body: some View {
         SettingsView(viewModel: viewModel)
@@ -129,10 +128,10 @@ struct SettingsTabContent: View {
 
 /// Wrapper that creates DetailViewModel for a pushed item
 struct DetailTabContent: View {
-    @StateObject private var viewModel: DetailViewModel
+    @State private var viewModel: DetailViewModel
 
     init(item: FeaturedItem) {
-        _viewModel = StateObject(wrappedValue: DetailViewModel(item: item))
+        _viewModel = State(initialValue: DetailViewModel(item: item))
     }
 
     var body: some View {
@@ -143,7 +142,7 @@ struct DetailTabContent: View {
 /// Wrapper that creates ProfileViewModel with navigation closures
 struct ProfileTabContent: View {
     let coordinator: AppCoordinator
-    @StateObject private var viewModel = ProfileViewModel()
+    @State private var viewModel = ProfileViewModel()
 
     var body: some View {
         ProfileView(viewModel: viewModel)
@@ -166,7 +165,7 @@ struct ProfileTabContent: View {
 /// Wrapper that creates LoginViewModel with login success closure
 struct LoginTabContent: View {
     let coordinator: AppCoordinator
-    @StateObject private var viewModel = LoginViewModel()
+    @State private var viewModel = LoginViewModel()
 
     var body: some View {
         LoginView(viewModel: viewModel)
diff --git a/Core/Package.swift b/Core/Package.swift
index e61a8491..14843bca 100644
--- a/Core/Package.swift
+++ b/Core/Package.swift
@@ -5,8 +5,8 @@ let package = Package(
     name: "Core",
     defaultLocalization: "en",
     platforms: [
-        .iOS(.v16),
-        .macCatalyst(.v16),
+        .iOS(.v17),
+        .macCatalyst(.v17),
     ],
     products: [
         .library(name: "FunCore", targets: ["FunCore"]),
diff --git a/Core/Sources/Core/ServiceLocator.swift b/Core/Sources/Core/ServiceLocator.swift
index a3a84f40..a1400555 100644
--- a/Core/Sources/Core/ServiceLocator.swift
+++ b/Core/Sources/Core/ServiceLocator.swift
@@ -5,13 +5,18 @@
 //  Central registry for dependency injection
 //
 
-import Combine
 import Foundation
 
 // MARK: - Service Key
 
 /// Enum defining all available services
-public enum ServiceKey {
+///
+/// `Sendable` conformance is required because `ServiceKey` is used as the element type of
+/// `StreamBroadcaster<ServiceKey>`, which enforces `Element: Sendable`. `AsyncStream` values
+/// flow across actor/concurrency boundaries between producer and consumer, so Swift 6 strict
+/// concurrency requires the element type to be `Sendable`. Combine's `PassthroughSubject` had
+/// no such requirement.
+public enum ServiceKey: Sendable {
     case network
     case logger
     case favorites
@@ -32,10 +37,10 @@ public class ServiceLocator {
     /// Registered services
     private var services: [ServiceKey: Any] = [:]
 
-    /// Emits the key whenever a service is registered
-    private let registrationSubject = PassthroughSubject<ServiceKey, Never>()
-    public var serviceDidRegisterPublisher: AnyPublisher<ServiceKey, Never> {
-        registrationSubject.eraseToAnyPublisher()
+    /// Broadcasts a key whenever a service is registered
+    private let registrationBroadcaster = StreamBroadcaster<ServiceKey>()
+    public var serviceRegistrations: AsyncStream<ServiceKey> {
+        registrationBroadcaster.makeStream()
     }
 
     private init() {}
@@ -43,7 +48,7 @@ public class ServiceLocator {
     /// Register a service
     public func register<T>(_ service: T, for key: ServiceKey) {
         services[key] = service
-        registrationSubject.send(key)
+        registrationBroadcaster.yield(key)
     }
 
     /// Resolve a service (crashes if not registered)
diff --git a/Core/Sources/Core/StreamBroadcaster.swift b/Core/Sources/Core/StreamBroadcaster.swift
new file mode 100644
index 00000000..990c3f60
--- /dev/null
+++ b/Core/Sources/Core/StreamBroadcaster.swift
@@ -0,0 +1,47 @@
+//
+//  StreamBroadcaster.swift
+//  Core
+//
+//  Multi-consumer AsyncStream broadcaster. Replaces Combine Subjects
+//  for one-to-many reactive state distribution.
+//
+
+import Foundation
+
+@MainActor
+public final class StreamBroadcaster<Element: Sendable> {
+
+    private var continuations: [UUID: AsyncStream<Element>.Continuation] = [:]
+
+    public init() {}
+
+    /// Creates a new AsyncStream that receives all future yielded values.
+    /// Each caller gets an independent stream — safe for multiple consumers.
+    /// Uses eager continuation registration so values yielded before iteration are buffered.
+    public func makeStream() -> AsyncStream<Element> {
+        let id = UUID()
+        let (stream, continuation) = AsyncStream.makeStream(of: Element.self)
+        continuations[id] = continuation
+        continuation.onTermination = { [weak self] _ in
+            Task { @MainActor in
+                self?.continuations.removeValue(forKey: id)
+            }
+        }
+        return stream
+    }
+
+    /// Sends a value to all active streams.
+    public func yield(_ value: Element) {
+        for continuation in continuations.values {
+            continuation.yield(value)
+        }
+    }
+
+    /// Finishes all active streams.
+    public func finish() {
+        for continuation in continuations.values {
+            continuation.finish()
+        }
+        continuations.removeAll()
+    }
+}
diff --git a/FunApp/FunApp.xcodeproj/project.pbxproj b/FunApp/FunApp.xcodeproj/project.pbxproj
index e68fe133..c7003623 100644
--- a/FunApp/FunApp.xcodeproj/project.pbxproj
+++ b/FunApp/FunApp.xcodeproj/project.pbxproj
@@ -229,7 +229,7 @@
 					"@executable_path/Frameworks",
 				);
 				MARKETING_VERSION = 2.1.0;
-				PRODUCT_BUNDLE_IDENTIFIER = com.charles.wang.FunApp.swiftui;
+				PRODUCT_BUNDLE_IDENTIFIER = com.charles.wang.FunApp.observation;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				STRING_CATALOG_GENERATE_SYMBOLS = YES;
 				SWIFT_APPROACHABLE_CONCURRENCY = YES;
@@ -260,7 +260,7 @@
 					"@executable_path/Frameworks",
 				);
 				MARKETING_VERSION = 2.1.0;
-				PRODUCT_BUNDLE_IDENTIFIER = com.charles.wang.FunApp.swiftui;
+				PRODUCT_BUNDLE_IDENTIFIER = com.charles.wang.FunApp.observation;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				STRING_CATALOG_GENERATE_SYMBOLS = YES;
 				SWIFT_APPROACHABLE_CONCURRENCY = YES;
@@ -324,7 +324,7 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				IPHONEOS_DEPLOYMENT_TARGET = 16.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 17.0;
 				LOCALIZATION_PREFERS_STRING_CATALOGS = YES;
 				MTL_ENABLE_DEBUG_INFO = INCLUDE_SOURCE;
 				MTL_FAST_MATH = YES;
@@ -381,7 +381,7 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				IPHONEOS_DEPLOYMENT_TARGET = 16.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 17.0;
 				LOCALIZATION_PREFERS_STRING_CATALOGS = YES;
 				MTL_ENABLE_DEBUG_INFO = NO;
 				MTL_FAST_MATH = YES;
diff --git a/FunApp/FunApp/Assets.xcassets/AppIcon.appiconset/AppIcon.png b/FunApp/FunApp/Assets.xcassets/AppIcon.appiconset/AppIcon.png
index af467781..56f6abac 100644
Binary files a/FunApp/FunApp/Assets.xcassets/AppIcon.appiconset/AppIcon.png and b/FunApp/FunApp/Assets.xcassets/AppIcon.appiconset/AppIcon.png differ
diff --git a/FunApp/FunApp/FunApp.swift b/FunApp/FunApp/FunApp.swift
index 7c6c110b..9ade2e01 100644
--- a/FunApp/FunApp/FunApp.swift
+++ b/FunApp/FunApp/FunApp.swift
@@ -12,7 +12,7 @@ import FunModel
 
 @main
 struct FunApp: App {
-    @StateObject private var coordinator = AppCoordinator(
+    @State private var coordinator = AppCoordinator(
         sessionFactory: AppSessionFactory()
     )
 
diff --git a/FunApp/FunApp/Info.plist b/FunApp/FunApp/Info.plist
index f825c8cf..c43a07b9 100644
--- a/FunApp/FunApp/Info.plist
+++ b/FunApp/FunApp/Info.plist
@@ -3,7 +3,7 @@
 <plist version="1.0">
 <dict>
 	<key>CFBundleDisplayName</key>
-	<string>Fun SwiftUI</string>
+	<string>Fun Observation</string>
 	<key>CFBundleURLTypes</key>
 	<array>
 		<dict>
diff --git a/Model/Package.swift b/Model/Package.swift
index 2ed4baec..7d516dbf 100644
--- a/Model/Package.swift
+++ b/Model/Package.swift
@@ -4,8 +4,8 @@ import PackageDescription
 let package = Package(
     name: "Model",
     platforms: [
-        .iOS(.v16),
-        .macCatalyst(.v16),
+        .iOS(.v17),
+        .macCatalyst(.v17),
     ],
     products: [
         .library(name: "FunModel", targets: ["FunModel"]),
diff --git a/Model/Sources/Model/FeaturedItem.swift b/Model/Sources/Model/FeaturedItem.swift
index a214ecc0..57ab4281 100644
--- a/Model/Sources/Model/FeaturedItem.swift
+++ b/Model/Sources/Model/FeaturedItem.swift
@@ -62,10 +62,10 @@ public extension FeaturedItem {
         category: "Concurrency"
     )
 
-    static let combine = FeaturedItem(
-        id: TechnologyItem.combine.rawValue,
-        title: "Combine",
-        subtitle: "Reactive programming",
+    static let asyncSequence = FeaturedItem(
+        id: TechnologyItem.asyncSequence.rawValue,
+        title: "AsyncSequence",
+        subtitle: "Reactive streams (zero Combine)",
         iconName: "arrow.triangle.merge",
         iconColor: .orange,
         category: "Reactive"
@@ -75,7 +75,7 @@ public extension FeaturedItem {
     static let swiftUI = FeaturedItem(
         id: TechnologyItem.swiftUI.rawValue,
         title: "SwiftUI",
-        subtitle: "Pure SwiftUI + NavigationStack",
+        subtitle: "Pure SwiftUI + @Observable",
         iconName: "swift",
         iconColor: .blue,
         category: "UI Framework"
@@ -84,7 +84,7 @@ public extension FeaturedItem {
     static let coordinator = FeaturedItem(
         id: TechnologyItem.coordinator.rawValue,
         title: "Coordinator",
-        subtitle: "Single ObservableObject",
+        subtitle: "Single @Observable AppCoordinator",
         iconName: "arrow.triangle.branch",
         iconColor: .purple,
         category: "Navigation"
@@ -94,7 +94,7 @@ public extension FeaturedItem {
     static let mvvm = FeaturedItem(
         id: TechnologyItem.mvvm.rawValue,
         title: "MVVM",
-        subtitle: "Architecture pattern",
+        subtitle: "@Observable ViewModels",
         iconName: "square.stack.3d.up",
         iconColor: .indigo,
         category: "Architecture"
@@ -189,7 +189,7 @@ public extension FeaturedItem {
     static let concurrencyPatterns = FeaturedItem(
         id: TechnologyItem.concurrencyPatterns.rawValue,
         title: "Concurrency Patterns",
-        subtitle: "Callbacks vs Combine vs async/await",
+        subtitle: "Callbacks vs AsyncStream vs async/await",
         iconName: "arrow.triangle.2.circlepath",
         iconColor: .orange,
         category: "Concurrency"
@@ -197,7 +197,7 @@ public extension FeaturedItem {
 
     static let deploymentTarget = FeaturedItem(
         id: TechnologyItem.deploymentTarget.rawValue,
-        title: "iOS 16+",
+        title: "iOS 17+",
         subtitle: "Minimum deployment target",
         iconName: "iphone.gen3",
         iconColor: .yellow,
@@ -205,7 +205,7 @@ public extension FeaturedItem {
     )
 
     // Carousel sets (2 items per page)
-    private static let carouselSet1: [FeaturedItem] = [.asyncAwait, .combine]
+    private static let carouselSet1: [FeaturedItem] = [.asyncAwait, .asyncSequence]
     private static let carouselSet2: [FeaturedItem] = [.swiftUI, .coordinator]
     private static let carouselSet3: [FeaturedItem] = [.mvvm, .spmModules]
     private static let carouselSet4: [FeaturedItem] = [.serviceLocator, .protocolOriented]
diff --git a/Model/Sources/Model/Services/FavoritesServiceProtocol.swift b/Model/Sources/Model/Services/FavoritesServiceProtocol.swift
index 826bbc0e..11a6ed17 100644
--- a/Model/Sources/Model/Services/FavoritesServiceProtocol.swift
+++ b/Model/Sources/Model/Services/FavoritesServiceProtocol.swift
@@ -5,15 +5,14 @@
 //  Protocol for favorites service
 //
 
-import Combine
 import Foundation
 
 @MainActor
 public protocol FavoritesServiceProtocol {
     var favorites: Set<String> { get }
 
-    /// Publisher that emits when favorites change
-    var favoritesDidChange: AnyPublisher<Set<String>, Never> { get }
+    /// Stream that emits when favorites change
+    var favoritesStream: AsyncStream<Set<String>> { get }
 
     func isFavorited(_ itemId: String) -> Bool
     func toggleFavorite(_ itemId: String)
@@ -23,27 +22,3 @@ public protocol FavoritesServiceProtocol {
     /// Clear all favorites and reset to default state
     func resetFavorites()
 }
-
-// MARK: - Swift Concurrency Alternative (iOS 15+)
-//
-// AsyncStream replaces AnyPublisher for service event delivery.
-// No Combine import needed. Available from iOS 15 (same as this branch).
-//
-//     // Protocol
-//     var favoritesChanges: AsyncStream<Set<String>> { get }
-//
-//     // Consumer — Task cancellation replaces AnyCancellable
-//     let stream = favoritesService.favoritesChanges
-//     observation = Task { [weak self] in
-//         for await favorites in stream {
-//             guard let self else { break }   // guard INSIDE loop to avoid retain cycle
-//             self.favoriteIds = favorites
-//         }
-//     }
-//
-// Key difference: AsyncStream only delivers future values (unlike @Published which emits
-// the current value on subscribe). Read the property directly at init time:
-//     favoriteIds = favoritesService.favorites      // current
-//     // then subscribe to favoritesChanges          // future
-//
-// See feature/observation for the full implementation.
diff --git a/Model/Sources/Model/Services/FeatureToggleServiceProtocol.swift b/Model/Sources/Model/Services/FeatureToggleServiceProtocol.swift
index c27862d2..c14ec1f2 100644
--- a/Model/Sources/Model/Services/FeatureToggleServiceProtocol.swift
+++ b/Model/Sources/Model/Services/FeatureToggleServiceProtocol.swift
@@ -5,7 +5,6 @@
 //  Protocol for feature toggle service
 //
 
-import Combine
 import Foundation
 
 @MainActor
@@ -15,6 +14,6 @@ public protocol FeatureToggleServiceProtocol: AnyObject {
     var aiSummary: Bool { get set }
     var appearanceMode: AppearanceMode { get set }
 
-    var featuredCarouselPublisher: AnyPublisher<Bool, Never> { get }
-    var appearanceModePublisher: AnyPublisher<AppearanceMode, Never> { get }
+    var featuredCarouselStream: AsyncStream<Bool> { get }
+    var appearanceModeStream: AsyncStream<AppearanceMode> { get }
 }
diff --git a/Model/Sources/Model/Services/ToastServiceProtocol.swift b/Model/Sources/Model/Services/ToastServiceProtocol.swift
index b92a61f3..d731a695 100644
--- a/Model/Sources/Model/Services/ToastServiceProtocol.swift
+++ b/Model/Sources/Model/Services/ToastServiceProtocol.swift
@@ -5,7 +5,6 @@
 //  Protocol for toast notification service
 //
 
-import Combine
 import Foundation
 
 public enum ToastType: Sendable {
@@ -36,6 +35,6 @@ public struct ToastEvent: Sendable {
 public protocol ToastServiceProtocol {
     func showToast(message: String, type: ToastType)
 
-    /// Publisher for toast events
-    var toastPublisher: AnyPublisher<ToastEvent, Never> { get }
+    /// Stream for toast events
+    var toastStream: AsyncStream<ToastEvent> { get }
 }
diff --git a/Model/Sources/Model/TechnologyDescriptions+Extended.swift b/Model/Sources/Model/TechnologyDescriptions+Extended.swift
index 5675c990..1598f36b 100644
--- a/Model/Sources/Model/TechnologyDescriptions+Extended.swift
+++ b/Model/Sources/Model/TechnologyDescriptions+Extended.swift
@@ -41,13 +41,11 @@ extension TechnologyDescriptions {
         """
 
     static let deploymentTargetDescription = """
-        This branch requires iOS 16.0 as the minimum deployment target.
+        This branch requires iOS 17.0 as the minimum deployment target.
 
-        iOS 16 unlocks:
-        • NavigationStack + NavigationPath for programmatic navigation
-        • .navigationDestination(for:) type-safe routing
-        • SwiftUI TabView improvements
-        • ShareLink and other modern SwiftUI APIs
+        iOS 17 unlocks:
+        • @Observable macro (Observation framework) — per-property tracking
+        • @Bindable for two-way bindings with @Observable classes
 
         Three branches demonstrate progressive iOS version requirements:
         • main: iOS 15+ (UIKit navigation + Combine)
@@ -82,21 +80,25 @@ extension TechnologyDescriptions {
         Note: A serial queue would execute fetches one at a time. The concurrent \
         queue runs all 3 in parallel, and the barrier flag ensures thread-safe writes.
 
-        2. Combine (Publishers.MergeMany):
+        2. AsyncStream (makeStream + continuation):
         ```swift
-        let publishers = (0..<3).map { page in
-            Future<[Item], Never> { promise in
-                promise(.success(fetchPage(page)))
-            }
+        let (stream, continuation) = AsyncStream.makeStream(of: (Int, [Item]).self)
+        for page in 0..<3 {
+            Task { continuation.yield((page, await fetchPage(page))) }
         }
-        Publishers.MergeMany(publishers)
-            .collect()
-            .map { $0.flatMap { $0 } }
-            .sink { items in self.allItems = items }
-            .store(in: &cancellables)
+        var results: [(Int, [Item])] = []
+        for await result in stream {
+            results.append(result)
+            if results.count == 3 { continuation.finish() }
+        }
+        let items = results.sorted { $0.0 < $1.0 }.flatMap { $0.1 }
         ```
+        Zero Combine — this branch uses AsyncStream for all reactive patterns.
+        Note: AsyncStream needs manual termination (`continuation.finish()` when count \
+        reached) because the stream has no concept of "all producers finished" — unlike \
+        TaskGroup which tracks its children automatically.
 
-        3. async/await (TaskGroup):
+        3. async/await (TaskGroup) — preferred for parallel work:
         ```swift
         let items = await withTaskGroup(of: (Int, [Item]).self) { group in
             for page in 0..<3 {
@@ -107,7 +109,9 @@ extension TechnologyDescriptions {
             return results.sorted { $0.0 < $1.0 }.flatMap { $0.1 }
         }
         ```
-
-        All three produce identical results. async/await is the cleanest syntax.
+        TaskGroup is structured concurrency: all children are scoped to the group, \
+        cancelling the parent cancels all children, and `for await` ends automatically \
+        when all children complete. Prefer TaskGroup for parallel work you own end-to-end; \
+        use AsyncStream for bridging event/callback APIs or reactive service streams.
         """
 }
diff --git a/Model/Sources/Model/TechnologyDescriptions.swift b/Model/Sources/Model/TechnologyDescriptions.swift
index 1ac7523f..08fef417 100644
--- a/Model/Sources/Model/TechnologyDescriptions.swift
+++ b/Model/Sources/Model/TechnologyDescriptions.swift
@@ -9,7 +9,7 @@ import Foundation
 
 public enum TechnologyItem: String, CaseIterable, Sendable {
     case asyncAwait = "asyncawait"
-    case combine = "combine"
+    case asyncSequence = "asyncsequence"
     case swiftUI = "swiftui"
     case coordinator = "coordinator"
     case mvvm = "mvvm"
@@ -40,7 +40,7 @@ public enum TechnologyDescriptions {
 
     private static let descriptions: [TechnologyItem: String] = [
         .asyncAwait: asyncAwaitDescription,
-        .combine: combineDescription,
+        .asyncSequence: asyncSequenceDescription,
         .swiftUI: swiftUIDescription,
         .coordinator: coordinatorDescription,
         .mvvm: mvvmDescription,
@@ -76,21 +76,36 @@ public enum TechnologyDescriptions {
         ```
         """
 
-    private static let combineDescription = """
-        Combine framework powers the reactive data flow throughout the app:
+    private static let asyncSequenceDescription = """
+        This branch replaced Combine entirely with Swift Concurrency:
 
-        • @Published properties for automatic UI updates
-        • Debounced search input (600ms) in Items screen
-        • Feature toggle change notifications
-        • Favorites state synchronization across views
-        • Scene lifecycle observation
+        • AsyncStream for service event delivery
+        • StreamBroadcaster for multi-consumer streams
+        • Task-based observation with for-await loops
+        • @Observable macro for ViewModel state
+        • didSet + Task.sleep for debounced search
 
-        Example from ItemsViewModel:
+        Example from ItemsViewModel (replacing .debounce):
         ```swift
+        // Before (Combine)
         $searchText
             .debounce(for: .milliseconds(600), scheduler: RunLoop.main)
             .sink { self.performSearch() }
             .store(in: &cancellables)
+
+        // After (AsyncSequence)
+        var searchText: String = "" {
+            didSet { handleSearchTextChanged() }
+        }
+
+        private func handleSearchTextChanged() {
+            debounceTask?.cancel()
+            debounceTask = Task { [weak self] in
+                try? await Task.sleep(for: .milliseconds(600))
+                guard !Task.isCancelled, let self else { return }
+                self.processSearchText()
+            }
+        }
         ```
         """
 
@@ -99,7 +114,8 @@ public enum TechnologyDescriptions {
 
         • All views built with SwiftUI (HomeView, ItemsView, etc.)
         • NavigationStack + NavigationPath for programmatic navigation
-        • @ObservedObject for ViewModel binding
+        • @Bindable for two-way ViewModel binding
+        • @State for ViewModel ownership
         • Modern modifiers: .refreshable, .swipeActions, .searchable
 
         Navigation:
@@ -116,9 +132,9 @@ public enum TechnologyDescriptions {
     private static let coordinatorDescription = """
         A single AppCoordinator manages all navigation:
 
-        • ObservableObject owning NavigationPath per tab
+        • @Observable class owning NavigationPath per tab
         • Programmatic push via path.append()
-        • Modal presentation via @Published booleans
+        • Modal presentation via @Bindable booleans
         • ViewModels receive navigation closures, not coordinator refs
 
         Flow:
@@ -135,9 +151,9 @@ public enum TechnologyDescriptions {
         • Model: Data structures and protocols
 
         Each screen follows this pattern:
-        HomeView (@ObservedObject viewModel)
+        HomeView (@Bindable viewModel)
             ↓ binds to
-        HomeViewModel (@Published state)
+        HomeViewModel (@Observable, per-property tracking)
             ↓ uses
         Services (Network, Favorites, etc.)
 
@@ -213,14 +229,15 @@ public enum TechnologyDescriptions {
         Runtime feature flags with reactive updates:
 
         • Persisted via UserDefaults
-        • Combine publisher for cross-component sync
+        • AsyncStream for cross-component sync
         • Toggle carousel visibility in Settings
 
         Usage:
         ```swift
-        featureToggleService.featuredCarouselPublisher
-            .sink { newValue in self.isCarouselEnabled = newValue }
-            .store(in: &cancellables)
+        let stream = featureToggleService.featuredCarouselStream
+        Task { for await newValue in stream {
+            self.isCarouselEnabled = newValue
+        }}
         ```
 
         Try it: Go to Settings → Toggle "Featured Carousel"
@@ -253,7 +270,7 @@ public enum TechnologyDescriptions {
         Example:
         ```swift
         @MainActor
-        public class HomeViewModel: ObservableObject {
+        @Observable public class HomeViewModel {
             // All UI-related code is main-thread safe
         }
 
diff --git a/Model/Sources/ModelTestSupport/MockFavoritesService.swift b/Model/Sources/ModelTestSupport/MockFavoritesService.swift
index fe21a200..b74bdb99 100644
--- a/Model/Sources/ModelTestSupport/MockFavoritesService.swift
+++ b/Model/Sources/ModelTestSupport/MockFavoritesService.swift
@@ -5,7 +5,7 @@
 //  Mock implementation of FavoritesServiceProtocol for testing
 //
 
-import Combine
+import FunCore
 import FunModel
 
 @MainActor
@@ -13,15 +13,14 @@ public final class MockFavoritesService: FavoritesServiceProtocol {
 
     public private(set) var favorites: Set<String>
 
-    private let favoritesSubject: CurrentValueSubject<Set<String>, Never>
+    private let favoritesBroadcaster = StreamBroadcaster<Set<String>>()
 
-    public var favoritesDidChange: AnyPublisher<Set<String>, Never> {
-        favoritesSubject.eraseToAnyPublisher()
+    public var favoritesStream: AsyncStream<Set<String>> {
+        favoritesBroadcaster.makeStream()
     }
 
     public init(initialFavorites: Set<String> = []) {
         self.favorites = initialFavorites
-        self.favoritesSubject = CurrentValueSubject(initialFavorites)
     }
 
     public func isFavorited(_ itemId: String) -> Bool {
@@ -34,21 +33,21 @@ public final class MockFavoritesService: FavoritesServiceProtocol {
         } else {
             favorites.insert(itemId)
         }
-        favoritesSubject.send(favorites)
+        favoritesBroadcaster.yield(favorites)
     }
 
     public func addFavorite(_ itemId: String) {
         favorites.insert(itemId)
-        favoritesSubject.send(favorites)
+        favoritesBroadcaster.yield(favorites)
     }
 
     public func removeFavorite(_ itemId: String) {
         favorites.remove(itemId)
-        favoritesSubject.send(favorites)
+        favoritesBroadcaster.yield(favorites)
     }
 
     public func resetFavorites() {
         favorites.removeAll()
-        favoritesSubject.send(favorites)
+        favoritesBroadcaster.yield(favorites)
     }
 }
diff --git a/Model/Sources/ModelTestSupport/MockFeatureToggleService.swift b/Model/Sources/ModelTestSupport/MockFeatureToggleService.swift
index 86489bc2..58489778 100644
--- a/Model/Sources/ModelTestSupport/MockFeatureToggleService.swift
+++ b/Model/Sources/ModelTestSupport/MockFeatureToggleService.swift
@@ -5,23 +5,36 @@
 //  Mock implementation of FeatureToggleServiceProtocol for testing
 //
 
-import Combine
+import FunCore
 import FunModel
 
 @MainActor
 public final class MockFeatureToggleService: FeatureToggleServiceProtocol {
 
-    @Published public var featuredCarousel: Bool
-    @Published public var simulateErrors: Bool
-    @Published public var aiSummary: Bool
-    @Published public var appearanceMode: AppearanceMode
+    public var featuredCarousel: Bool {
+        didSet {
+            guard featuredCarousel != oldValue else { return }
+            carouselBroadcaster.yield(featuredCarousel)
+        }
+    }
+    public var simulateErrors: Bool
+    public var aiSummary: Bool
+    public var appearanceMode: AppearanceMode {
+        didSet {
+            guard appearanceMode != oldValue else { return }
+            appearanceBroadcaster.yield(appearanceMode)
+        }
+    }
+
+    private let carouselBroadcaster = StreamBroadcaster<Bool>()
+    private let appearanceBroadcaster = StreamBroadcaster<AppearanceMode>()
 
-    public var featuredCarouselPublisher: AnyPublisher<Bool, Never> {
-        $featuredCarousel.removeDuplicates().eraseToAnyPublisher()
+    public var featuredCarouselStream: AsyncStream<Bool> {
+        carouselBroadcaster.makeStream()
     }
 
-    public var appearanceModePublisher: AnyPublisher<AppearanceMode, Never> {
-        $appearanceMode.removeDuplicates().eraseToAnyPublisher()
+    public var appearanceModeStream: AsyncStream<AppearanceMode> {
+        appearanceBroadcaster.makeStream()
     }
 
     public init(featuredCarousel: Bool = true, simulateErrors: Bool = false, aiSummary: Bool = true, appearanceMode: AppearanceMode = .system) {
diff --git a/Model/Sources/ModelTestSupport/MockToastService.swift b/Model/Sources/ModelTestSupport/MockToastService.swift
index e1d5c07d..dae6323c 100644
--- a/Model/Sources/ModelTestSupport/MockToastService.swift
+++ b/Model/Sources/ModelTestSupport/MockToastService.swift
@@ -5,16 +5,16 @@
 //  Mock implementation of ToastServiceProtocol for testing
 //
 
-import Combine
+import FunCore
 import FunModel
 
 @MainActor
 public final class MockToastService: ToastServiceProtocol {
 
-    private let toastSubject = PassthroughSubject<ToastEvent, Never>()
+    private let toastBroadcaster = StreamBroadcaster<ToastEvent>()
 
-    public var toastPublisher: AnyPublisher<ToastEvent, Never> {
-        toastSubject.eraseToAnyPublisher()
+    public var toastStream: AsyncStream<ToastEvent> {
+        toastBroadcaster.makeStream()
     }
 
     public var showToastCalled = false
@@ -30,6 +30,6 @@ public final class MockToastService: ToastServiceProtocol {
         lastType = type
         let event = ToastEvent(message: message, type: type)
         toastHistory.append(event)
-        toastSubject.send(event)
+        toastBroadcaster.yield(event)
     }
 }
diff --git a/Model/Tests/ModelTests/DeepLinkTests.swift b/Model/Tests/ModelTests/DeepLinkTests.swift
index e1f0b738..1e41138c 100644
--- a/Model/Tests/ModelTests/DeepLinkTests.swift
+++ b/Model/Tests/ModelTests/DeepLinkTests.swift
@@ -58,10 +58,10 @@ struct DeepLinkTests {
 
     @Test("Parse item deep link with different ID")
     func parseItemWithDifferentId() {
-        let url = URL(string: "funapp://item/combine")!
+        let url = URL(string: "funapp://item/asyncsequence")!
         let deepLink = DeepLink(url: url)
 
-        #expect(deepLink == DeepLink.item(id: "combine"))
+        #expect(deepLink == DeepLink.item(id: "asyncsequence"))
     }
 
     // MARK: - Profile Deep Link
diff --git a/Model/Tests/ModelTests/TechnologyDescriptionsTests.swift b/Model/Tests/ModelTests/TechnologyDescriptionsTests.swift
index 543663ad..a44fef74 100644
--- a/Model/Tests/ModelTests/TechnologyDescriptionsTests.swift
+++ b/Model/Tests/ModelTests/TechnologyDescriptionsTests.swift
@@ -64,10 +64,10 @@ struct TechnologyDescriptionsTests {
         #expect(description.lowercased().contains("async"))
     }
 
-    @Test("combine description mentions reactive")
-    func testCombineContent() {
-        let description = TechnologyDescriptions.description(for: TechnologyItem.combine.rawValue)
-        #expect(description.lowercased().contains("reactive") || description.lowercased().contains("combine"))
+    @Test("asyncSequence description mentions stream or observable")
+    func testAsyncSequenceContent() {
+        let description = TechnologyDescriptions.description(for: TechnologyItem.asyncSequence.rawValue)
+        #expect(description.lowercased().contains("asyncstream") || description.lowercased().contains("observable"))
     }
 
     // MARK: - Alignment with FeaturedItem Tests
diff --git a/README.md b/README.md
index 431ba4ce..51dc4aa5 100644
--- a/README.md
+++ b/README.md
@@ -7,7 +7,7 @@ A modern iOS application demonstrating clean architecture (MVVM-C), Swift Concur
 Three branches show progressive modernization:
 - UIKit + SwiftUI + Combine (iOS 15+) — [`main`](https://github.com/g-enius/Fun-iOS/tree/main)
 - Pure SwiftUI + Combine (iOS 16+) — [`navigation-stack`](https://github.com/g-enius/Fun-iOS/tree/feature/navigation-stack) - [PR](https://github.com/g-enius/Fun-iOS/pull/3)
-- Pure SwiftUI + AsyncSequence (iOS 17+) — [`observation`](https://github.com/g-enius/Fun-iOS/tree/feature/observation) - [PR](https://github.com/g-enius/Fun-iOS/pull/6)
+- Pure SwiftUI + @Observable + AsyncSequence (iOS 17+) — [`observation`](https://github.com/g-enius/Fun-iOS/tree/feature/observation) - [PR](https://github.com/g-enius/Fun-iOS/pull/6)
 
 Android counterpart: [Fun-Android](https://github.com/g-enius/Fun-Android).
 
@@ -29,7 +29,7 @@ Three branches demonstrate progressive modernization — same app, three archite
 |---|---|---|---|
 | **Best for** | **iOS 15+** | [![iOS 16+](https://img.shields.io/badge/iOS_16+-blue)](#) | [![iOS 17+](https://img.shields.io/badge/iOS_17+-blue)](#) |
 | **UI framework** | **UIKit + SwiftUI** | **SwiftUI** [![🚫 UIKit](https://img.shields.io/badge/🚫_UIKit-blue)](#) | ← same |
-| **Reactive** | **Combine** | ← same | **AsyncSequence** [![🚫 Combine](https://img.shields.io/badge/🚫_Combine-blue)](#) |
+| **Reactive** | **Combine** | ← same | **@Observable** + **AsyncStream** [![🚫 Combine](https://img.shields.io/badge/🚫_Combine-blue)](#) |
 | **ViewModel** | `ObservableObject` + `@Published` | ← same | **@Observable** macro |
 | **View binding** | `@ObservedObject` | ← same | **@Bindable** / **@State** |
 | **Service events** | `AnyPublisher` + `Subject` | ← same | **AsyncStream** + **StreamBroadcaster** |
@@ -40,6 +40,8 @@ Three branches demonstrate progressive modernization — same app, three archite
 | LLM | Foundation Models (iOS 26+) | ← same | ← same |
 | Testing | Swift Testing, swift-snapshot-testing | ← same | ← same |
 
+> **Why iOS 17?** The `observation` branch replaces Combine with two independent technologies: **`@Observable`** (Observation framework, iOS 17) for ViewModel → View reactivity, and **`AsyncStream`** for service event streams. `AsyncSequence`/`AsyncStream` themselves are available since iOS 13, but [`AsyncStream.makeStream(of:)`](https://github.com/swiftlang/swift-evolution/blob/main/proposals/0388-async-stream-factory.md) (SE-0388) — used for eager continuation registration in `StreamBroadcaster` — requires iOS 17. Neither depends on the other; they coincidentally share the same deployment target.
+
 ### UIKit + SwiftUI vs Pure SwiftUI
 
 | Aspect | `main` (UIKit + SwiftUI) | `navigation-stack`&nbsp;/&nbsp;`observation`&nbsp;(Pure&nbsp;SwiftUI) |
@@ -185,7 +187,7 @@ Deep links received during login are queued and executed after authentication.
 ## Features
 
 - **Session-Scoped DI**: Clean service lifecycle per app flow — no stale state
-- **Reactive Data Flow**: Combine framework with `@Published` properties
+- **Reactive Data Flow**: `@Observable` for ViewModel state, `AsyncStream` + `StreamBroadcaster` for service events
 - **Feature Toggles**: Runtime flags persisted via services
 - **AI Summary**: On-device LLM summarisation using Apple Intelligence / Foundation Models (iOS 26+)
 - **Error Handling**: Centralized `AppError` enum with toast notifications
@@ -205,7 +207,7 @@ Deep links received during login are queued and executed after authentication.
 
 ### Requirements
 - Xcode 16.0+
-- iOS 15.0+
+- iOS 17.0+
 - Swift 6.0
 
 ### Installation
diff --git a/Services/Package.swift b/Services/Package.swift
index 034e1c00..1979802a 100644
--- a/Services/Package.swift
+++ b/Services/Package.swift
@@ -4,8 +4,8 @@ import PackageDescription
 let package = Package(
     name: "Services",
     platforms: [
-        .iOS(.v16),
-        .macCatalyst(.v16),
+        .iOS(.v17),
+        .macCatalyst(.v17),
     ],
     products: [
         .library(name: "FunServices", targets: ["FunServices"]),
diff --git a/Services/Sources/Services/CoreServices/DefaultFavoritesService.swift b/Services/Sources/Services/CoreServices/DefaultFavoritesService.swift
index 49f1929f..37a2eb53 100644
--- a/Services/Sources/Services/CoreServices/DefaultFavoritesService.swift
+++ b/Services/Sources/Services/CoreServices/DefaultFavoritesService.swift
@@ -5,10 +5,10 @@
 //  Default implementation of FavoritesServiceProtocol
 //
 
-import Combine
 import Foundation
 import OSLog
 
+import FunCore
 import FunModel
 
 @MainActor
@@ -19,39 +19,18 @@ public final class DefaultFavoritesService: FavoritesServiceProtocol {
 
     public private(set) var favorites: Set<String> {
         didSet {
+            guard favorites != oldValue else { return }
             saveFavorites()
-            favoritesSubject.send(favorites)
+            favoritesBroadcaster.yield(favorites)
         }
     }
 
-    private let favoritesSubject: CurrentValueSubject<Set<String>, Never>
+    private let favoritesBroadcaster = StreamBroadcaster<Set<String>>()
 
-    public var favoritesDidChange: AnyPublisher<Set<String>, Never> {
-        favoritesSubject.eraseToAnyPublisher()
+    public var favoritesStream: AsyncStream<Set<String>> {
+        favoritesBroadcaster.makeStream()
     }
 
-    // MARK: - Swift Concurrency Alternative (iOS 15+)
-    //
-    // Replace CurrentValueSubject with StreamBroadcaster (a multi-consumer AsyncStream utility):
-    //
-    //     private let favoritesBroadcaster = StreamBroadcaster<Set<String>>()
-    //
-    //     var favoritesChanges: AsyncStream<Set<String>> {
-    //         favoritesBroadcaster.makeStream()   // each consumer gets its own stream
-    //     }
-    //
-    //     // In didSet:
-    //     didSet {
-    //         saveFavorites()
-    //         favoritesBroadcaster.yield(favorites)  // delivers to all active consumers
-    //     }
-    //
-    // StreamBroadcaster.makeStream() returns a new AsyncStream per consumer — unlike
-    // CurrentValueSubject where all subscribers share one publisher. Each consumer's
-    // stream is cleaned up automatically when the consuming Task is cancelled.
-    //
-    // See Core/Sources/Core/StreamBroadcaster.swift on feature/observation.
-
     public init() {
         let loaded: Set<String>
         if let data = UserDefaults.standard.data(forKey: .favorites) {
@@ -65,7 +44,6 @@ public final class DefaultFavoritesService: FavoritesServiceProtocol {
             loaded = Self.defaultFavorites
         }
         self.favorites = loaded
-        self.favoritesSubject = CurrentValueSubject(loaded)
     }
 
     public func isFavorited(_ itemId: String) -> Bool {
diff --git a/Services/Sources/Services/CoreServices/DefaultFeatureToggleService.swift b/Services/Sources/Services/CoreServices/DefaultFeatureToggleService.swift
index 02658215..6d0308a3 100644
--- a/Services/Sources/Services/CoreServices/DefaultFeatureToggleService.swift
+++ b/Services/Sources/Services/CoreServices/DefaultFeatureToggleService.swift
@@ -5,9 +5,9 @@
 //  Default implementation of FeatureToggleServiceProtocol
 //
 
-import Combine
 import Foundation
 
+import FunCore
 import FunModel
 
 @MainActor
@@ -15,27 +15,45 @@ public final class DefaultFeatureToggleService: FeatureToggleServiceProtocol {
 
     // MARK: - Feature Toggles
 
-    @Published public var featuredCarousel: Bool {
-        didSet { UserDefaults.standard.set(featuredCarousel, forKey: .featureCarousel) }
+    public var featuredCarousel: Bool {
+        didSet {
+            guard featuredCarousel != oldValue else { return }
+            UserDefaults.standard.set(featuredCarousel, forKey: .featureCarousel)
+            carouselBroadcaster.yield(featuredCarousel)
+        }
     }
-    @Published public var simulateErrors: Bool {
-        didSet { UserDefaults.standard.set(simulateErrors, forKey: .simulateErrors) }
+
+    public var simulateErrors: Bool {
+        didSet {
+            UserDefaults.standard.set(simulateErrors, forKey: .simulateErrors)
+        }
     }
-    @Published public var aiSummary: Bool {
-        didSet { UserDefaults.standard.set(aiSummary, forKey: .aiSummary) }
+
+    public var aiSummary: Bool {
+        didSet {
+            UserDefaults.standard.set(aiSummary, forKey: .aiSummary)
+        }
     }
-    @Published public var appearanceMode: AppearanceMode {
-        didSet { UserDefaults.standard.set(appearanceMode.rawValue, forKey: .appearanceMode) }
+
+    public var appearanceMode: AppearanceMode {
+        didSet {
+            guard appearanceMode != oldValue else { return }
+            UserDefaults.standard.set(appearanceMode.rawValue, forKey: .appearanceMode)
+            appearanceBroadcaster.yield(appearanceMode)
+        }
     }
 
-    // MARK: - Publishers
+    // MARK: - Streams
+
+    private let carouselBroadcaster = StreamBroadcaster<Bool>()
+    private let appearanceBroadcaster = StreamBroadcaster<AppearanceMode>()
 
-    public var featuredCarouselPublisher: AnyPublisher<Bool, Never> {
-        $featuredCarousel.removeDuplicates().eraseToAnyPublisher()
+    public var featuredCarouselStream: AsyncStream<Bool> {
+        carouselBroadcaster.makeStream()
     }
 
-    public var appearanceModePublisher: AnyPublisher<AppearanceMode, Never> {
-        $appearanceMode.removeDuplicates().eraseToAnyPublisher()
+    public var appearanceModeStream: AsyncStream<AppearanceMode> {
+        appearanceBroadcaster.makeStream()
     }
 
     // MARK: - Initialization
diff --git a/Services/Sources/Services/CoreServices/DefaultToastService.swift b/Services/Sources/Services/CoreServices/DefaultToastService.swift
index 4e18bba5..38c4bae1 100644
--- a/Services/Sources/Services/CoreServices/DefaultToastService.swift
+++ b/Services/Sources/Services/CoreServices/DefaultToastService.swift
@@ -5,20 +5,20 @@
 //  Default implementation of ToastServiceProtocol
 //
 
-import Combine
 import Foundation
 
+import FunCore
 import FunModel
 
 @MainActor
 public final class DefaultToastService: ToastServiceProtocol {
 
-    // MARK: - Combine Publisher
+    // MARK: - Stream
 
-    private let toastSubject = PassthroughSubject<ToastEvent, Never>()
+    private let toastBroadcaster = StreamBroadcaster<ToastEvent>()
 
-    public var toastPublisher: AnyPublisher<ToastEvent, Never> {
-        toastSubject.eraseToAnyPublisher()
+    public var toastStream: AsyncStream<ToastEvent> {
+        toastBroadcaster.makeStream()
     }
 
     // MARK: - Initialization
@@ -28,6 +28,6 @@ public final class DefaultToastService: ToastServiceProtocol {
     // MARK: - ToastServiceProtocol
 
     public func showToast(message: String, type: ToastType) {
-        toastSubject.send(ToastEvent(message: message, type: type))
+        toastBroadcaster.yield(ToastEvent(message: message, type: type))
     }
 }
diff --git a/Services/Tests/ServicesTests/DefaultFavoritesServiceTests.swift b/Services/Tests/ServicesTests/DefaultFavoritesServiceTests.swift
index 2f0138a1..6d968331 100644
--- a/Services/Tests/ServicesTests/DefaultFavoritesServiceTests.swift
+++ b/Services/Tests/ServicesTests/DefaultFavoritesServiceTests.swift
@@ -7,7 +7,6 @@
 
 import Testing
 import Foundation
-import Combine
 @testable import FunServices
 @testable import FunModel
 
@@ -167,48 +166,42 @@ struct DefaultFavoritesServiceTests {
         #expect(service.favorites.count == countBefore)
     }
 
-    // MARK: - Publisher Tests
+    // MARK: - Stream Tests
 
-    @Test("favoritesDidChange publishes when favorites change")
-    func testFavoritesDidChangePublisher() async {
+    @Test("favoritesStream emits when favorites change")
+    func testFavoritesChangesStream() async {
         clearUserDefaults()
         let service = DefaultFavoritesService()
 
-        var receivedFavorites: Set<String>?
-        var cancellables = Set<AnyCancellable>()
-
-        service.favoritesDidChange
-            .dropFirst() // Skip the initial value from CurrentValueSubject
-            .sink { favorites in
-                receivedFavorites = favorites
-            }
-            .store(in: &cancellables)
-
+        // Eager continuation: stream registered, values buffered before iteration
+        let stream = service.favoritesStream
         service.addFavorite("item2")
 
+        var iterator = stream.makeAsyncIterator()
+        let receivedFavorites = await iterator.next()
+
         #expect(receivedFavorites != nil)
         #expect(receivedFavorites?.contains("item2") == true)
     }
 
-    @Test("favoritesDidChange publishes on toggle")
-    func testFavoritesDidChangeOnToggle() async {
+    @Test("favoritesStream emits on toggle")
+    func testFavoritesChangesOnToggle() async {
         clearUserDefaults()
         let service = DefaultFavoritesService()
 
-        var publishCount = 0
-        var cancellables = Set<AnyCancellable>()
+        let stream = service.favoritesStream
+        service.toggleFavorite("item1")
+        service.toggleFavorite("item1")
 
-        service.favoritesDidChange
-            .dropFirst() // Skip the initial value from CurrentValueSubject
-            .sink { _ in
-                publishCount += 1
+        var emitCount = 0
+        var iterator = stream.makeAsyncIterator()
+        for _ in 0..<2 {
+            if await iterator.next() != nil {
+                emitCount += 1
             }
-            .store(in: &cancellables)
+        }
 
-        service.toggleFavorite( "item1")
-        service.toggleFavorite( "item1")
-
-        #expect(publishCount == 2)
+        #expect(emitCount == 2)
     }
 
     // MARK: - Reset Tests
@@ -232,25 +225,19 @@ struct DefaultFavoritesServiceTests {
         #expect(!service.favorites.contains("item3"))
     }
 
-    @Test("resetFavorites publishes default set")
-    func testResetFavoritesPublishesDefault() async {
+    @Test("resetFavorites emits default set via stream")
+    func testResetFavoritesEmitsDefault() async {
         clearUserDefaults()
         let service = DefaultFavoritesService()
 
         service.addFavorite("item2")
 
-        var receivedFavorites: Set<String>?
-        var cancellables = Set<AnyCancellable>()
-
-        service.favoritesDidChange
-            .dropFirst()
-            .sink { favorites in
-                receivedFavorites = favorites
-            }
-            .store(in: &cancellables)
-
+        let stream = service.favoritesStream
         service.resetFavorites()
 
+        var iterator = stream.makeAsyncIterator()
+        let receivedFavorites = await iterator.next()
+
         #expect(receivedFavorites != nil)
         #expect(receivedFavorites == Set(["item1"]))
     }
diff --git a/Services/Tests/ServicesTests/DefaultFeatureToggleServiceTests.swift b/Services/Tests/ServicesTests/DefaultFeatureToggleServiceTests.swift
index 9ee6d2f7..1fe21460 100644
--- a/Services/Tests/ServicesTests/DefaultFeatureToggleServiceTests.swift
+++ b/Services/Tests/ServicesTests/DefaultFeatureToggleServiceTests.swift
@@ -7,7 +7,6 @@
 
 import Testing
 import Foundation
-import Combine
 @testable import FunServices
 @testable import FunModel
 
@@ -47,23 +46,18 @@ struct DefaultFeatureToggleServiceTests {
         #expect(UserDefaults.standard.bool(forKey: UserDefaultsKey.featureCarousel.rawValue) == true)
     }
 
-    // MARK: - Combine Publisher Tests
+    // MARK: - Stream Tests
 
-    @Test("Setting featured carousel emits via publisher")
-    func testFeaturedCarouselEmitsViaPublisher() async {
+    @Test("Setting featured carousel emits via stream")
+    func testFeaturedCarouselEmitsViaStream() async {
         clearUserDefaults()
         let service = DefaultFeatureToggleService()
-        var receivedValue: Bool?
-        var cancellables = Set<AnyCancellable>()
-
-        service.featuredCarouselPublisher
-            .sink { receivedValue = $0 }
-            .store(in: &cancellables)
 
+        let stream = service.featuredCarouselStream
         service.featuredCarousel = false
 
-        // Yield to allow publisher propagation
-        await Task.yield()
+        var iterator = stream.makeAsyncIterator()
+        let receivedValue = await iterator.next()
 
         #expect(receivedValue == false)
     }
@@ -130,20 +124,16 @@ struct DefaultFeatureToggleServiceTests {
         #expect(UserDefaults.standard.string(forKey: UserDefaultsKey.appearanceMode.rawValue) == "system")
     }
 
-    @Test("AppearanceMode emits via publisher")
-    func testAppearanceModeEmitsViaPublisher() async {
+    @Test("AppearanceMode emits via stream")
+    func testAppearanceModeEmitsViaStream() async {
         clearUserDefaults()
         let service = DefaultFeatureToggleService()
-        var receivedValue: AppearanceMode?
-        var cancellables = Set<AnyCancellable>()
-
-        service.appearanceModePublisher
-            .sink { receivedValue = $0 }
-            .store(in: &cancellables)
 
+        let stream = service.appearanceModeStream
         service.appearanceMode = .dark
 
-        await Task.yield()
+        var iterator = stream.makeAsyncIterator()
+        let receivedValue = await iterator.next()
 
         #expect(receivedValue == .dark)
     }
diff --git a/Services/Tests/ServicesTests/DefaultToastServiceTests.swift b/Services/Tests/ServicesTests/DefaultToastServiceTests.swift
index 54d6c966..9a21d727 100644
--- a/Services/Tests/ServicesTests/DefaultToastServiceTests.swift
+++ b/Services/Tests/ServicesTests/DefaultToastServiceTests.swift
@@ -7,7 +7,6 @@
 
 import Testing
 import Foundation
-import Combine
 @testable import FunServices
 @testable import FunModel
 
@@ -15,37 +14,19 @@ import Combine
 @MainActor
 struct DefaultToastServiceTests {
 
-    // MARK: - Initialization Tests
-
-    @Test("Service initializes with no pending events")
-    func testInitialization() async {
-        let service = DefaultToastService()
-        var eventCount = 0
-        var cancellables = Set<AnyCancellable>()
-
-        service.toastPublisher
-            .sink { _ in eventCount += 1 }
-            .store(in: &cancellables)
-
-        #expect(eventCount == 0)
-    }
-
     // MARK: - Show Toast Tests
 
-    @Test("showToast emits event via publisher")
+    @Test("showToast emits event via stream")
     func testShowToastEmitsEvent() async {
         let service = DefaultToastService()
-        var receivedEvent: ToastEvent?
-        var cancellables = Set<AnyCancellable>()
-
-        service.toastPublisher
-            .sink { event in
-                receivedEvent = event
-            }
-            .store(in: &cancellables)
 
+        // Eager continuation: stream registered, values buffered before iteration
+        let stream = service.toastStream
         service.showToast(message: "Test message", type: .success)
 
+        var iterator = stream.makeAsyncIterator()
+        let receivedEvent = await iterator.next()
+
         #expect(receivedEvent != nil)
         #expect(receivedEvent?.message == "Test message")
         #expect(receivedEvent?.type == .success)
@@ -54,17 +35,13 @@ struct DefaultToastServiceTests {
     @Test("showToast with error type")
     func testShowToastErrorType() async {
         let service = DefaultToastService()
-        var receivedEvent: ToastEvent?
-        var cancellables = Set<AnyCancellable>()
-
-        service.toastPublisher
-            .sink { event in
-                receivedEvent = event
-            }
-            .store(in: &cancellables)
 
+        let stream = service.toastStream
         service.showToast(message: "Error occurred", type: .error)
 
+        var iterator = stream.makeAsyncIterator()
+        let receivedEvent = await iterator.next()
+
         #expect(receivedEvent?.type == .error)
         #expect(receivedEvent?.message == "Error occurred")
     }
@@ -72,17 +49,13 @@ struct DefaultToastServiceTests {
     @Test("showToast with info type")
     func testShowToastInfoType() async {
         let service = DefaultToastService()
-        var receivedEvent: ToastEvent?
-        var cancellables = Set<AnyCancellable>()
-
-        service.toastPublisher
-            .sink { event in
-                receivedEvent = event
-            }
-            .store(in: &cancellables)
 
+        let stream = service.toastStream
         service.showToast(message: "Info message", type: .info)
 
+        var iterator = stream.makeAsyncIterator()
+        let receivedEvent = await iterator.next()
+
         #expect(receivedEvent?.type == .info)
     }
 
@@ -91,58 +64,48 @@ struct DefaultToastServiceTests {
     @Test("Multiple toasts all emit events")
     func testMultipleToastsEmitEvents() async {
         let service = DefaultToastService()
-        var receivedEvents: [ToastEvent] = []
-        var cancellables = Set<AnyCancellable>()
-
-        service.toastPublisher
-            .sink { event in
-                receivedEvents.append(event)
-            }
-            .store(in: &cancellables)
 
+        let stream = service.toastStream
         service.showToast(message: "First", type: .success)
         service.showToast(message: "Second", type: .error)
         service.showToast(message: "Third", type: .info)
 
+        var receivedEvents: [ToastEvent] = []
+        var iterator = stream.makeAsyncIterator()
+        for _ in 0..<3 {
+            if let event = await iterator.next() {
+                receivedEvents.append(event)
+            }
+        }
+
         #expect(receivedEvents.count == 3)
         #expect(receivedEvents[0].message == "First")
         #expect(receivedEvents[1].message == "Second")
         #expect(receivedEvents[2].message == "Third")
     }
 
-    // MARK: - Publisher Behavior Tests
-
-    @Test("No events received before showToast is called")
-    func testNoEventsBeforeShowToast() async {
-        let service = DefaultToastService()
-        var eventCount = 0
-        var cancellables = Set<AnyCancellable>()
-
-        service.toastPublisher
-            .sink { _ in
-                eventCount += 1
-            }
-            .store(in: &cancellables)
-
-        #expect(eventCount == 0)
-    }
+    // MARK: - Stream Behavior Tests
 
     @Test("Late subscriber does not receive past events")
     func testLateSubscriberMissesPastEvents() async {
         let service = DefaultToastService()
-        var cancellables = Set<AnyCancellable>()
 
-        // Emit before subscribing
+        // Emit before subscribing — no continuation exists, value is lost
         service.showToast(message: "Before subscribe", type: .info)
 
         var receivedEvents: [ToastEvent] = []
-        service.toastPublisher
-            .sink { event in
+        let stream = service.toastStream
+        let task = Task {
+            for await event in stream {
                 receivedEvents.append(event)
+                break
             }
-            .store(in: &cancellables)
+        }
+
+        // Verify absence: yield to let any pending work run
+        await Task.yield()
 
-        // PassthroughSubject does not replay - should be empty
         #expect(receivedEvents.isEmpty)
+        task.cancel()
     }
 }
diff --git a/UI/Package.swift b/UI/Package.swift
index ac291be4..56455c35 100644
--- a/UI/Package.swift
+++ b/UI/Package.swift
@@ -4,8 +4,8 @@ import PackageDescription
 let package = Package(
     name: "UI",
     platforms: [
-        .iOS(.v16),
-        .macCatalyst(.v16),
+        .iOS(.v17),
+        .macCatalyst(.v17),
     ],
     products: [
         .library(name: "FunUI", targets: ["FunUI"]),
diff --git a/UI/Sources/UI/Detail/DetailView.swift b/UI/Sources/UI/Detail/DetailView.swift
index 1b668ffd..4c377c98 100644
--- a/UI/Sources/UI/Detail/DetailView.swift
+++ b/UI/Sources/UI/Detail/DetailView.swift
@@ -11,7 +11,7 @@ import FunCore
 import FunViewModel
 
 public struct DetailView: View {
-    @ObservedObject private var viewModel: DetailViewModel
+    private var viewModel: DetailViewModel
 
     public init(viewModel: DetailViewModel) {
         self.viewModel = viewModel
diff --git a/UI/Sources/UI/Home/HomeView.swift b/UI/Sources/UI/Home/HomeView.swift
index cc62ec6c..b22c0100 100644
--- a/UI/Sources/UI/Home/HomeView.swift
+++ b/UI/Sources/UI/Home/HomeView.swift
@@ -12,7 +12,7 @@ import FunModel
 import FunViewModel
 
 public struct HomeView: View {
-    @ObservedObject private var viewModel: HomeViewModel
+    @Bindable private var viewModel: HomeViewModel
 
     public init(viewModel: HomeViewModel) {
         self.viewModel = viewModel
diff --git a/UI/Sources/UI/Items/ItemsView.swift b/UI/Sources/UI/Items/ItemsView.swift
index 86be00bd..23b939b1 100644
--- a/UI/Sources/UI/Items/ItemsView.swift
+++ b/UI/Sources/UI/Items/ItemsView.swift
@@ -12,7 +12,7 @@ import FunModel
 import FunViewModel
 
 public struct ItemsView: View {
-    @ObservedObject private var viewModel: ItemsViewModel
+    private var viewModel: ItemsViewModel
 
     public init(viewModel: ItemsViewModel) {
         self.viewModel = viewModel
@@ -28,7 +28,7 @@ public struct ItemsView: View {
 // MARK: - Content View
 
 private struct ItemsMainContent: View {
-    @ObservedObject var viewModel: ItemsViewModel
+    @Bindable var viewModel: ItemsViewModel
     @FocusState private var isSearchFocused: Bool
     @State private var hasAppeared = false
 
@@ -58,7 +58,7 @@ private struct ItemsMainContent: View {
 // MARK: - Shared Components
 
 private struct CategoryFilterView: View {
-    @ObservedObject var viewModel: ItemsViewModel
+    var viewModel: ItemsViewModel
 
     var body: some View {
         ScrollView(.horizontal, showsIndicators: false) {
@@ -92,7 +92,7 @@ private struct CategoryFilterView: View {
 }
 
 private struct ItemsContentView: View {
-    @ObservedObject var viewModel: ItemsViewModel
+    var viewModel: ItemsViewModel
     var isSearchFocused: FocusState<Bool>.Binding
 
     var body: some View {
@@ -143,7 +143,7 @@ private struct ItemsContentView: View {
 
 private struct ItemRowView: View {
     let item: FeaturedItem
-    @ObservedObject var viewModel: ItemsViewModel
+    var viewModel: ItemsViewModel
     var isSearchFocused: FocusState<Bool>.Binding
 
     private var isFavorited: Bool {
diff --git a/UI/Sources/UI/Login/LoginView.swift b/UI/Sources/UI/Login/LoginView.swift
index a1ac823e..1fca0f6e 100644
--- a/UI/Sources/UI/Login/LoginView.swift
+++ b/UI/Sources/UI/Login/LoginView.swift
@@ -11,7 +11,7 @@ import FunCore
 import FunViewModel
 
 public struct LoginView: View {
-    @ObservedObject private var viewModel: LoginViewModel
+    private var viewModel: LoginViewModel
 
     public init(viewModel: LoginViewModel) {
         self.viewModel = viewModel
diff --git a/UI/Sources/UI/Preview Content/PreviewHelper.swift b/UI/Sources/UI/Preview Content/PreviewHelper.swift
index cc691cc4..7a1dfd65 100644
--- a/UI/Sources/UI/Preview Content/PreviewHelper.swift	
+++ b/UI/Sources/UI/Preview Content/PreviewHelper.swift	
@@ -5,7 +5,6 @@
 //  Helper utilities for SwiftUI previews
 //
 
-import Combine
 import SwiftUI
 
 import FunCore
@@ -88,31 +87,34 @@ private final class PreviewLoggerService: LoggerService {
 @MainActor
 private final class PreviewFavoritesService: FavoritesServiceProtocol {
     var favorites: Set<String>
-    private let subject: CurrentValueSubject<Set<String>, Never>
-    var favoritesDidChange: AnyPublisher<Set<String>, Never> { subject.eraseToAnyPublisher() }
+    private let broadcaster = StreamBroadcaster<Set<String>>()
+    var favoritesStream: AsyncStream<Set<String>> { broadcaster.makeStream() }
 
     init(initialFavorites: Set<String> = []) {
         self.favorites = initialFavorites
-        self.subject = CurrentValueSubject(initialFavorites)
     }
     func isFavorited(_ itemId: String) -> Bool { favorites.contains(itemId) }
     func toggleFavorite(_ itemId: String) {
         if favorites.contains(itemId) { favorites.remove(itemId) } else { favorites.insert(itemId) }
-        subject.send(favorites)
+        broadcaster.yield(favorites)
     }
-    func addFavorite(_ itemId: String) { favorites.insert(itemId); subject.send(favorites) }
-    func removeFavorite(_ itemId: String) { favorites.remove(itemId); subject.send(favorites) }
-    func resetFavorites() { favorites.removeAll(); subject.send(favorites) }
+    func addFavorite(_ itemId: String) { favorites.insert(itemId); broadcaster.yield(favorites) }
+    func removeFavorite(_ itemId: String) { favorites.remove(itemId); broadcaster.yield(favorites) }
+    func resetFavorites() { favorites.removeAll(); broadcaster.yield(favorites) }
 }
 
 @MainActor
 private final class PreviewFeatureToggleService: FeatureToggleServiceProtocol {
-    @Published var featuredCarousel: Bool = true
-    @Published var simulateErrors: Bool = false
-    @Published var aiSummary: Bool = true
-    @Published var appearanceMode: AppearanceMode = .system
-    var featuredCarouselPublisher: AnyPublisher<Bool, Never> { $featuredCarousel.eraseToAnyPublisher() }
-    var appearanceModePublisher: AnyPublisher<AppearanceMode, Never> { $appearanceMode.eraseToAnyPublisher() }
+    var featuredCarousel: Bool = true
+    var simulateErrors: Bool = false
+    var aiSummary: Bool = true
+    var appearanceMode: AppearanceMode = .system
+
+    private let carouselBroadcaster = StreamBroadcaster<Bool>()
+    private let appearanceBroadcaster = StreamBroadcaster<AppearanceMode>()
+
+    var featuredCarouselStream: AsyncStream<Bool> { carouselBroadcaster.makeStream() }
+    var appearanceModeStream: AsyncStream<AppearanceMode> { appearanceBroadcaster.makeStream() }
 }
 
 @MainActor
@@ -133,7 +135,7 @@ private final class PreviewNetworkService: NetworkService {
 
 @MainActor
 private final class PreviewToastService: ToastServiceProtocol {
-    private let subject = PassthroughSubject<ToastEvent, Never>()
-    var toastPublisher: AnyPublisher<ToastEvent, Never> { subject.eraseToAnyPublisher() }
-    func showToast(message: String, type: ToastType) { subject.send(ToastEvent(message: message, type: type)) }
+    private let broadcaster = StreamBroadcaster<ToastEvent>()
+    var toastStream: AsyncStream<ToastEvent> { broadcaster.makeStream() }
+    func showToast(message: String, type: ToastType) { broadcaster.yield(ToastEvent(message: message, type: type)) }
 }
diff --git a/UI/Sources/UI/Profile/ProfileView.swift b/UI/Sources/UI/Profile/ProfileView.swift
index cfac569e..7f174237 100644
--- a/UI/Sources/UI/Profile/ProfileView.swift
+++ b/UI/Sources/UI/Profile/ProfileView.swift
@@ -11,7 +11,7 @@ import FunCore
 import FunViewModel
 
 public struct ProfileView: View {
-    @ObservedObject private var viewModel: ProfileViewModel
+    private var viewModel: ProfileViewModel
 
     public init(viewModel: ProfileViewModel) {
         self.viewModel = viewModel
diff --git a/UI/Sources/UI/Settings/SettingsView.swift b/UI/Sources/UI/Settings/SettingsView.swift
index e3bc4c93..84cee5ac 100644
--- a/UI/Sources/UI/Settings/SettingsView.swift
+++ b/UI/Sources/UI/Settings/SettingsView.swift
@@ -12,7 +12,7 @@ import FunModel
 import FunViewModel
 
 public struct SettingsView: View {
-    @ObservedObject private var viewModel: SettingsViewModel
+    @Bindable private var viewModel: SettingsViewModel
 
     public init(viewModel: SettingsViewModel) {
         self.viewModel = viewModel
diff --git a/UI/Tests/UITests/SnapshotTests/DetailViewSnapshotTests.swift b/UI/Tests/UITests/SnapshotTests/DetailViewSnapshotTests.swift
index a454a877..6f290e9c 100644
--- a/UI/Tests/UITests/SnapshotTests/DetailViewSnapshotTests.swift
+++ b/UI/Tests/UITests/SnapshotTests/DetailViewSnapshotTests.swift
@@ -7,7 +7,6 @@
 
 import XCTest
 import SwiftUI
-import Combine
 import SnapshotTesting
 @testable import FunUI
 @testable import FunViewModel
diff --git a/UI/Tests/UITests/SnapshotTests/HomeViewSnapshotTests.swift b/UI/Tests/UITests/SnapshotTests/HomeViewSnapshotTests.swift
index 77f7add1..7cb02a0b 100644
--- a/UI/Tests/UITests/SnapshotTests/HomeViewSnapshotTests.swift
+++ b/UI/Tests/UITests/SnapshotTests/HomeViewSnapshotTests.swift
@@ -7,7 +7,6 @@
 
 import XCTest
 import SwiftUI
-import Combine
 import SnapshotTesting
 @testable import FunUI
 @testable import FunViewModel
diff --git a/UI/Tests/UITests/SnapshotTests/ItemsViewSnapshotTests.swift b/UI/Tests/UITests/SnapshotTests/ItemsViewSnapshotTests.swift
index d4f41d05..75fdbe91 100644
--- a/UI/Tests/UITests/SnapshotTests/ItemsViewSnapshotTests.swift
+++ b/UI/Tests/UITests/SnapshotTests/ItemsViewSnapshotTests.swift
@@ -7,7 +7,6 @@
 
 import XCTest
 import SwiftUI
-import Combine
 import SnapshotTesting
 @testable import FunUI
 @testable import FunViewModel
diff --git a/UI/Tests/UITests/SnapshotTests/ProfileViewSnapshotTests.swift b/UI/Tests/UITests/SnapshotTests/ProfileViewSnapshotTests.swift
index ff59ba3f..026239a4 100644
--- a/UI/Tests/UITests/SnapshotTests/ProfileViewSnapshotTests.swift
+++ b/UI/Tests/UITests/SnapshotTests/ProfileViewSnapshotTests.swift
@@ -7,7 +7,6 @@
 
 import XCTest
 import SwiftUI
-import Combine
 import SnapshotTesting
 @testable import FunUI
 @testable import FunViewModel
diff --git a/UI/Tests/UITests/SnapshotTests/SettingsViewSnapshotTests.swift b/UI/Tests/UITests/SnapshotTests/SettingsViewSnapshotTests.swift
index e2722b43..6d5d194c 100644
--- a/UI/Tests/UITests/SnapshotTests/SettingsViewSnapshotTests.swift
+++ b/UI/Tests/UITests/SnapshotTests/SettingsViewSnapshotTests.swift
@@ -7,7 +7,6 @@
 
 import XCTest
 import SwiftUI
-import Combine
 import SnapshotTesting
 @testable import FunUI
 @testable import FunViewModel
diff --git a/UI/Tests/UITests/SnapshotTests/__Snapshots__/DetailViewSnapshotTests/testDetailView_darkMode.1.png b/UI/Tests/UITests/SnapshotTests/__Snapshots__/DetailViewSnapshotTests/testDetailView_darkMode.1.png
index 6a954c5a..2a51b03e 100644
Binary files a/UI/Tests/UITests/SnapshotTests/__Snapshots__/DetailViewSnapshotTests/testDetailView_darkMode.1.png and b/UI/Tests/UITests/SnapshotTests/__Snapshots__/DetailViewSnapshotTests/testDetailView_darkMode.1.png differ
diff --git a/UI/Tests/UITests/SnapshotTests/__Snapshots__/DetailViewSnapshotTests/testDetailView_defaultState.1.png b/UI/Tests/UITests/SnapshotTests/__Snapshots__/DetailViewSnapshotTests/testDetailView_defaultState.1.png
index 0acff49d..e8b79504 100644
Binary files a/UI/Tests/UITests/SnapshotTests/__Snapshots__/DetailViewSnapshotTests/testDetailView_defaultState.1.png and b/UI/Tests/UITests/SnapshotTests/__Snapshots__/DetailViewSnapshotTests/testDetailView_defaultState.1.png differ
diff --git a/UI/Tests/UITests/SnapshotTests/__Snapshots__/DetailViewSnapshotTests/testDetailView_favorited.1.png b/UI/Tests/UITests/SnapshotTests/__Snapshots__/DetailViewSnapshotTests/testDetailView_favorited.1.png
index 0acff49d..e8b79504 100644
Binary files a/UI/Tests/UITests/SnapshotTests/__Snapshots__/DetailViewSnapshotTests/testDetailView_favorited.1.png and b/UI/Tests/UITests/SnapshotTests/__Snapshots__/DetailViewSnapshotTests/testDetailView_favorited.1.png differ
diff --git a/UI/Tests/UITests/SnapshotTests/__Snapshots__/HomeViewSnapshotTests/testHomeView_iPad_landscape.1.png b/UI/Tests/UITests/SnapshotTests/__Snapshots__/HomeViewSnapshotTests/testHomeView_iPad_landscape.1.png
index 9a2210d4..11e6e77b 100644
Binary files a/UI/Tests/UITests/SnapshotTests/__Snapshots__/HomeViewSnapshotTests/testHomeView_iPad_landscape.1.png and b/UI/Tests/UITests/SnapshotTests/__Snapshots__/HomeViewSnapshotTests/testHomeView_iPad_landscape.1.png differ
diff --git a/UI/Tests/UITests/SnapshotTests/__Snapshots__/HomeViewSnapshotTests/testHomeView_iPad_portrait.1.png b/UI/Tests/UITests/SnapshotTests/__Snapshots__/HomeViewSnapshotTests/testHomeView_iPad_portrait.1.png
index 9a2210d4..11e6e77b 100644
Binary files a/UI/Tests/UITests/SnapshotTests/__Snapshots__/HomeViewSnapshotTests/testHomeView_iPad_portrait.1.png and b/UI/Tests/UITests/SnapshotTests/__Snapshots__/HomeViewSnapshotTests/testHomeView_iPad_portrait.1.png differ
diff --git a/UI/Tests/UITests/SnapshotTests/__Snapshots__/HomeViewSnapshotTests/testHomeView_withCarouselDisabled.1.png b/UI/Tests/UITests/SnapshotTests/__Snapshots__/HomeViewSnapshotTests/testHomeView_withCarouselDisabled.1.png
index 5899a9ee..608cbdf5 100644
Binary files a/UI/Tests/UITests/SnapshotTests/__Snapshots__/HomeViewSnapshotTests/testHomeView_withCarouselDisabled.1.png and b/UI/Tests/UITests/SnapshotTests/__Snapshots__/HomeViewSnapshotTests/testHomeView_withCarouselDisabled.1.png differ
diff --git a/UI/Tests/UITests/SnapshotTests/__Snapshots__/HomeViewSnapshotTests/testHomeView_withCarouselEnabled.1.png b/UI/Tests/UITests/SnapshotTests/__Snapshots__/HomeViewSnapshotTests/testHomeView_withCarouselEnabled.1.png
index 5899a9ee..608cbdf5 100644
Binary files a/UI/Tests/UITests/SnapshotTests/__Snapshots__/HomeViewSnapshotTests/testHomeView_withCarouselEnabled.1.png and b/UI/Tests/UITests/SnapshotTests/__Snapshots__/HomeViewSnapshotTests/testHomeView_withCarouselEnabled.1.png differ
diff --git a/UI/Tests/UITests/SnapshotTests/__Snapshots__/ItemsViewSnapshotTests/testItemsView_darkMode.1.png b/UI/Tests/UITests/SnapshotTests/__Snapshots__/ItemsViewSnapshotTests/testItemsView_darkMode.1.png
index 8fa1694e..6e94b0fd 100644
Binary files a/UI/Tests/UITests/SnapshotTests/__Snapshots__/ItemsViewSnapshotTests/testItemsView_darkMode.1.png and b/UI/Tests/UITests/SnapshotTests/__Snapshots__/ItemsViewSnapshotTests/testItemsView_darkMode.1.png differ
diff --git a/UI/Tests/UITests/SnapshotTests/__Snapshots__/ItemsViewSnapshotTests/testItemsView_defaultState.1.png b/UI/Tests/UITests/SnapshotTests/__Snapshots__/ItemsViewSnapshotTests/testItemsView_defaultState.1.png
index 529fcb87..6e94b0fd 100644
Binary files a/UI/Tests/UITests/SnapshotTests/__Snapshots__/ItemsViewSnapshotTests/testItemsView_defaultState.1.png and b/UI/Tests/UITests/SnapshotTests/__Snapshots__/ItemsViewSnapshotTests/testItemsView_defaultState.1.png differ
diff --git a/UI/Tests/UITests/SnapshotTests/__Snapshots__/ItemsViewSnapshotTests/testItemsView_withSearchText.1.png b/UI/Tests/UITests/SnapshotTests/__Snapshots__/ItemsViewSnapshotTests/testItemsView_withSearchText.1.png
index 24ebd180..eac4924f 100644
Binary files a/UI/Tests/UITests/SnapshotTests/__Snapshots__/ItemsViewSnapshotTests/testItemsView_withSearchText.1.png and b/UI/Tests/UITests/SnapshotTests/__Snapshots__/ItemsViewSnapshotTests/testItemsView_withSearchText.1.png differ
diff --git a/UI/Tests/UITests/SnapshotTests/__Snapshots__/LoginViewSnapshotTests/testLoginView_defaultState.1.png b/UI/Tests/UITests/SnapshotTests/__Snapshots__/LoginViewSnapshotTests/testLoginView_defaultState.1.png
index 3a9e7742..adf79c67 100644
Binary files a/UI/Tests/UITests/SnapshotTests/__Snapshots__/LoginViewSnapshotTests/testLoginView_defaultState.1.png and b/UI/Tests/UITests/SnapshotTests/__Snapshots__/LoginViewSnapshotTests/testLoginView_defaultState.1.png differ
diff --git a/UI/Tests/UITests/SnapshotTests/__Snapshots__/LoginViewSnapshotTests/testLoginView_loggingInState.1.png b/UI/Tests/UITests/SnapshotTests/__Snapshots__/LoginViewSnapshotTests/testLoginView_loggingInState.1.png
index 640e5b02..5254c405 100644
Binary files a/UI/Tests/UITests/SnapshotTests/__Snapshots__/LoginViewSnapshotTests/testLoginView_loggingInState.1.png and b/UI/Tests/UITests/SnapshotTests/__Snapshots__/LoginViewSnapshotTests/testLoginView_loggingInState.1.png differ
diff --git a/UI/Tests/UITests/SnapshotTests/__Snapshots__/ProfileViewSnapshotTests/testProfileView_defaultState.1.png b/UI/Tests/UITests/SnapshotTests/__Snapshots__/ProfileViewSnapshotTests/testProfileView_defaultState.1.png
index ab16062d..8451c204 100644
Binary files a/UI/Tests/UITests/SnapshotTests/__Snapshots__/ProfileViewSnapshotTests/testProfileView_defaultState.1.png and b/UI/Tests/UITests/SnapshotTests/__Snapshots__/ProfileViewSnapshotTests/testProfileView_defaultState.1.png differ
diff --git a/UI/Tests/UITests/SnapshotTests/__Snapshots__/SettingsViewSnapshotTests/testSettingsView_carouselDisabled.1.png b/UI/Tests/UITests/SnapshotTests/__Snapshots__/SettingsViewSnapshotTests/testSettingsView_carouselDisabled.1.png
index 3dd1ef08..08918558 100644
Binary files a/UI/Tests/UITests/SnapshotTests/__Snapshots__/SettingsViewSnapshotTests/testSettingsView_carouselDisabled.1.png and b/UI/Tests/UITests/SnapshotTests/__Snapshots__/SettingsViewSnapshotTests/testSettingsView_carouselDisabled.1.png differ
diff --git a/UI/Tests/UITests/SnapshotTests/__Snapshots__/SettingsViewSnapshotTests/testSettingsView_carouselEnabled.1.png b/UI/Tests/UITests/SnapshotTests/__Snapshots__/SettingsViewSnapshotTests/testSettingsView_carouselEnabled.1.png
index 88c15b6d..18d95894 100644
Binary files a/UI/Tests/UITests/SnapshotTests/__Snapshots__/SettingsViewSnapshotTests/testSettingsView_carouselEnabled.1.png and b/UI/Tests/UITests/SnapshotTests/__Snapshots__/SettingsViewSnapshotTests/testSettingsView_carouselEnabled.1.png differ
diff --git a/UI/Tests/UITests/SnapshotTests/__Snapshots__/SettingsViewSnapshotTests/testSettingsView_defaultState.1.png b/UI/Tests/UITests/SnapshotTests/__Snapshots__/SettingsViewSnapshotTests/testSettingsView_defaultState.1.png
index 88c15b6d..18d95894 100644
Binary files a/UI/Tests/UITests/SnapshotTests/__Snapshots__/SettingsViewSnapshotTests/testSettingsView_defaultState.1.png and b/UI/Tests/UITests/SnapshotTests/__Snapshots__/SettingsViewSnapshotTests/testSettingsView_defaultState.1.png differ
diff --git a/ViewModel/Package.swift b/ViewModel/Package.swift
index bae15600..3e393eee 100644
--- a/ViewModel/Package.swift
+++ b/ViewModel/Package.swift
@@ -4,8 +4,8 @@ import PackageDescription
 let package = Package(
     name: "ViewModel",
     platforms: [
-        .iOS(.v16),
-        .macCatalyst(.v16),
+        .iOS(.v17),
+        .macCatalyst(.v17),
     ],
     products: [
         .library(name: "FunViewModel", targets: ["FunViewModel"]),
diff --git a/ViewModel/Sources/ViewModel/Detail/DetailViewModel.swift b/ViewModel/Sources/ViewModel/Detail/DetailViewModel.swift
index b417032a..40915c76 100644
--- a/ViewModel/Sources/ViewModel/Detail/DetailViewModel.swift
+++ b/ViewModel/Sources/ViewModel/Detail/DetailViewModel.swift
@@ -5,31 +5,32 @@
 //  ViewModel for Detail screen
 //
 
-import Combine
 import Foundation
+import Observation
 
 import FunCore
 import FunModel
 
 @MainActor
-public class DetailViewModel: ObservableObject {
+@Observable
+public class DetailViewModel {
 
     // MARK: - Services
 
-    @Service(.logger) private var logger: LoggerService
-    @Service(.favorites) private var favoritesService: FavoritesServiceProtocol
-    @Service(.ai) private var aiService: AIServiceProtocol
-    @Service(.featureToggles) private var featureToggleService: FeatureToggleServiceProtocol
+    @ObservationIgnored @Service(.logger) private var logger: LoggerService
+    @ObservationIgnored @Service(.favorites) private var favoritesService: FavoritesServiceProtocol
+    @ObservationIgnored @Service(.ai) private var aiService: AIServiceProtocol
+    @ObservationIgnored @Service(.featureToggles) private var featureToggleService: FeatureToggleServiceProtocol
 
-    // MARK: - Published State
+    // MARK: - State
 
-    @Published public var itemTitle: String
-    @Published public var category: String
-    @Published public var itemDescription: String
-    @Published public var isFavorited: Bool = false
-    @Published public var summary: String = ""
-    @Published public var isSummarizing: Bool = false
-    @Published public var summaryError: String = ""
+    public var itemTitle: String
+    public var category: String
+    public var itemDescription: String
+    public var isFavorited: Bool = false
+    public var summary: String = ""
+    public var isSummarizing: Bool = false
+    public var summaryError: String = ""
 
     public var showAISummary: Bool {
         featureToggleService.aiSummary && aiService.isAvailable
@@ -42,8 +43,8 @@ public class DetailViewModel: ObservableObject {
 
     // MARK: - Private Properties
 
-    private var cancellables = Set<AnyCancellable>()
-    private var itemId: String
+    @ObservationIgnored private var favoritesObservation: Task<Void, Never>?
+    @ObservationIgnored private var itemId: String
 
     // MARK: - Initialization
 
@@ -56,15 +57,21 @@ public class DetailViewModel: ObservableObject {
         observeFavoritesChanges()
     }
 
+    deinit {
+        favoritesObservation?.cancel()
+    }
+
     // MARK: - Setup
 
     private func observeFavoritesChanges() {
-        favoritesService.favoritesDidChange
-            .sink { [weak self] favorites in
-                guard let self else { return }
-                self.isFavorited = favorites.contains(self.itemId)
+        let stream = favoritesService.favoritesStream
+        let itemId = self.itemId
+        favoritesObservation = Task { [weak self] in
+            for await favorites in stream {
+                guard let self else { break }
+                self.isFavorited = favorites.contains(itemId)
             }
-            .store(in: &cancellables)
+        }
     }
 
     // MARK: - Actions
diff --git a/ViewModel/Sources/ViewModel/Home/HomeViewModel.swift b/ViewModel/Sources/ViewModel/Home/HomeViewModel.swift
index 30a727ae..443914d4 100644
--- a/ViewModel/Sources/ViewModel/Home/HomeViewModel.swift
+++ b/ViewModel/Sources/ViewModel/Home/HomeViewModel.swift
@@ -5,14 +5,15 @@
 //  ViewModel for Home screen
 //
 
-import Combine
 import Foundation
+import Observation
 
 import FunCore
 import FunModel
 
 @MainActor
-public class HomeViewModel: ObservableObject {
+@Observable
+public class HomeViewModel {
 
     // MARK: - Navigation Closures
 
@@ -21,27 +22,27 @@ public class HomeViewModel: ObservableObject {
 
     // MARK: - Services
 
-    @Service(.logger) private var logger: LoggerService
-    @Service(.network) private var networkService: NetworkService
-    @Service(.favorites) private var favoritesService: FavoritesServiceProtocol
-    @Service(.toast) private var toastService: ToastServiceProtocol
+    @ObservationIgnored @Service(.logger) private var logger: LoggerService
+    @ObservationIgnored @Service(.network) private var networkService: NetworkService
+    @ObservationIgnored @Service(.favorites) private var favoritesService: FavoritesServiceProtocol
+    @ObservationIgnored @Service(.toast) private var toastService: ToastServiceProtocol
+    @ObservationIgnored @Service(.featureToggles) private var featureToggleService: FeatureToggleServiceProtocol
 
-    @Service(.featureToggles) private var featureToggleService: FeatureToggleServiceProtocol
+    // MARK: - State
 
-    // MARK: - Published State
-
-    @Published public var featuredItems: [[FeaturedItem]] = []
-    @Published public var currentCarouselIndex: Int = 0
-    @Published public var isLoading: Bool = false
-    @Published public var isCarouselEnabled: Bool = true
-    @Published public private(set) var favoriteIds: Set<String> = []
-    @Published public var hasError: Bool = false
+    public var featuredItems: [[FeaturedItem]] = []
+    public var currentCarouselIndex: Int = 0
+    public var isLoading: Bool = false
+    public var isCarouselEnabled: Bool = true
+    public var favoriteIds: Set<String> = []
+    public var hasError: Bool = false
 
     // MARK: - Private Properties
 
-    private var cancellables = Set<AnyCancellable>()
-    private var loadTask: Task<Void, Never>?
-    private var hasLoadedInitialData: Bool = false
+    @ObservationIgnored private var loadTask: Task<Void, Never>?
+    @ObservationIgnored private var carouselObservation: Task<Void, Never>?
+    @ObservationIgnored private var favoritesObservation: Task<Void, Never>?
+    @ObservationIgnored private var hasLoadedInitialData: Bool = false
 
     // MARK: - Initialization
 
@@ -52,6 +53,9 @@ public class HomeViewModel: ObservableObject {
         self.onShowDetail = onShowDetail
         self.onShowProfile = onShowProfile
 
+        // Initialize from current service values (AsyncStream only emits future changes)
+        isCarouselEnabled = featureToggleService.featuredCarousel
+
         observeFeatureToggleChanges()
         observeFavoritesChanges()
 
@@ -63,28 +67,37 @@ public class HomeViewModel: ObservableObject {
 
     deinit {
         loadTask?.cancel()
+        carouselObservation?.cancel()
+        favoritesObservation?.cancel()
     }
 
-    // MARK: - Feature Toggle Observation (Combine)
+    // MARK: - Feature Toggle Observation
 
     private func observeFeatureToggleChanges() {
-        featureToggleService.featuredCarouselPublisher
-            .sink { [weak self] newValue in
-                self?.isCarouselEnabled = newValue
-                self?.logger.log("Carousel visibility changed to: \(newValue)")
+        let stream = featureToggleService.featuredCarouselStream
+        carouselObservation = Task { [weak self] in
+            for await newValue in stream {
+                guard let self else { break }
+                self.isCarouselEnabled = newValue
+                self.logger.log("Carousel visibility changed to: \(newValue)")
             }
-            .store(in: &cancellables)
+        }
     }
 
     // MARK: - Favorites Observation
 
     private func observeFavoritesChanges() {
-        // CurrentValueSubject replays current value on subscribe — no manual init needed
-        favoritesService.favoritesDidChange
-            .sink { [weak self] newFavorites in
-                self?.favoriteIds = newFavorites
+        // Initialize with current favorites
+        favoriteIds = favoritesService.favorites
+
+        // Observe future changes
+        let stream = favoritesService.favoritesStream
+        favoritesObservation = Task { [weak self] in
+            for await newFavorites in stream {
+                guard let self else { break }
+                self.favoriteIds = newFavorites
             }
-            .store(in: &cancellables)
+        }
     }
 
     // MARK: - Favorites
@@ -118,7 +131,8 @@ public class HomeViewModel: ObservableObject {
         } catch {
             hasError = true
             featuredItems = []
-            toastService.showToast(message: AppError.networkError.errorDescription ?? L10n.Error.unknownError, type: .error)
+            let errorMessage = AppError.networkError.errorDescription ?? L10n.Error.unknownError
+            toastService.showToast(message: errorMessage, type: .error)
         }
 
         isLoading = false
diff --git a/ViewModel/Sources/ViewModel/Items/ItemsViewModel.swift b/ViewModel/Sources/ViewModel/Items/ItemsViewModel.swift
index f704b283..bbffe19d 100644
--- a/ViewModel/Sources/ViewModel/Items/ItemsViewModel.swift
+++ b/ViewModel/Sources/ViewModel/Items/ItemsViewModel.swift
@@ -5,14 +5,15 @@
 //  ViewModel for Items screen - combines search, filter, and items list
 //
 
-import Combine
 import Foundation
+import Observation
 
 import FunCore
 import FunModel
 
 @MainActor
-public class ItemsViewModel: ObservableObject {
+@Observable
+public class ItemsViewModel {
 
     // MARK: - Navigation Closures
 
@@ -20,24 +21,29 @@ public class ItemsViewModel: ObservableObject {
 
     // MARK: - Services
 
-    @Service(.logger) private var logger: LoggerService
-    @Service(.network) private var networkService: NetworkService
-    @Service(.favorites) private var favoritesService: FavoritesServiceProtocol
-    @Service(.toast) private var toastService: ToastServiceProtocol
-    @Service(.featureToggles) private var featureToggleService: FeatureToggleServiceProtocol
+    @ObservationIgnored @Service(.logger) private var logger: LoggerService
+    @ObservationIgnored @Service(.network) private var networkService: NetworkService
+    @ObservationIgnored @Service(.favorites) private var favoritesService: FavoritesServiceProtocol
+    @ObservationIgnored @Service(.toast) private var toastService: ToastServiceProtocol
+    @ObservationIgnored @Service(.featureToggles) private var featureToggleService: FeatureToggleServiceProtocol
 
-    // MARK: - Published State
+    // MARK: - State
 
-    @Published public var items: [FeaturedItem] = []
-    @Published public private(set) var favoriteIds: Set<String> = []
+    public var items: [FeaturedItem] = []
+    public var favoriteIds: Set<String> = []
 
     // Search & Filter State
-    @Published public var searchText: String = ""
-    @Published public var selectedCategory: String = L10n.Items.categoryAll
-    @Published public var isSearching: Bool = false
-    @Published public var needsMoreCharacters: Bool = false
-    @Published public var hasError: Bool = false
-    @Published public private(set) var isLoading: Bool = false
+    public var searchText: String = "" {
+        didSet {
+            guard searchText != oldValue else { return }
+            handleSearchTextChanged()
+        }
+    }
+    public var selectedCategory: String = L10n.Items.categoryAll
+    public var isSearching: Bool = false
+    public var needsMoreCharacters: Bool = false
+    public var hasError: Bool = false
+    public private(set) var isLoading: Bool = false
 
     // MARK: - Configuration
 
@@ -46,17 +52,17 @@ public class ItemsViewModel: ObservableObject {
 
     // MARK: - Private Properties
 
-    private var cancellables = Set<AnyCancellable>()
-    private var allItems: [FeaturedItem] = []
-    private var loadTask: Task<Void, Never>?
-    private var searchTask: Task<Void, Never>?
+    @ObservationIgnored private var allItems: [FeaturedItem] = []
+    @ObservationIgnored private var loadTask: Task<Void, Never>?
+    @ObservationIgnored private var searchTask: Task<Void, Never>?
+    @ObservationIgnored private var debounceTask: Task<Void, Never>?
+    @ObservationIgnored private var favoritesObservation: Task<Void, Never>?
 
     // MARK: - Initialization
 
     public init(onShowDetail: ((FeaturedItem) -> Void)? = nil) {
         self.onShowDetail = onShowDetail
         observeFavoritesChanges()
-        setupSearchBinding()
 
         loadTask = Task { [weak self] in
             await self?.loadItems()
@@ -66,47 +72,51 @@ public class ItemsViewModel: ObservableObject {
     deinit {
         loadTask?.cancel()
         searchTask?.cancel()
+        debounceTask?.cancel()
+        favoritesObservation?.cancel()
     }
 
     // MARK: - Setup
 
-    private func setupSearchBinding() {
-        // Debounce search text with minimum character requirement
-        $searchText
-            .dropFirst() // Skip initial value
-            .debounce(for: .milliseconds(600), scheduler: RunLoop.main)
-            .removeDuplicates()
-            .sink { [weak self] text in
-                guard let self else { return }
-                let trimmed = text.trimmingCharacters(in: .whitespacesAndNewlines)
-
-                if trimmed.isEmpty {
-                    // Empty search - show all items
-                    self.needsMoreCharacters = false
-                    self.performSearch()
-                } else if trimmed.count < self.minimumSearchCharacters {
-                    // Below minimum - show "keep typing" unless in error state
-                    if !self.hasError {
-                        self.needsMoreCharacters = true
-                        self.items = []
-                    }
-                    self.isSearching = false
-                } else {
-                    // Meets minimum - perform search
-                    self.needsMoreCharacters = false
-                    self.performSearch()
-                }
+    private func handleSearchTextChanged() {
+        debounceTask?.cancel()
+        debounceTask = Task { [weak self] in
+            try? await Task.sleep(for: .milliseconds(600))
+            guard !Task.isCancelled, let self else { return }
+            self.processSearchText()
+        }
+    }
+
+    private func processSearchText() {
+        let trimmed = searchText.trimmingCharacters(in: .whitespacesAndNewlines)
+
+        if trimmed.isEmpty {
+            needsMoreCharacters = false
+            performSearch()
+        } else if trimmed.count < minimumSearchCharacters {
+            if !hasError {
+                needsMoreCharacters = true
+                items = []
             }
-            .store(in: &cancellables)
+            isSearching = false
+        } else {
+            needsMoreCharacters = false
+            performSearch()
+        }
     }
 
     private func observeFavoritesChanges() {
-        // CurrentValueSubject replays current value on subscribe — no manual init needed
-        favoritesService.favoritesDidChange
-            .sink { [weak self] newFavorites in
-                self?.favoriteIds = newFavorites
+        // Initialize with current favorites
+        favoriteIds = favoritesService.favorites
+
+        // Observe future changes
+        let stream = favoritesService.favoritesStream
+        favoritesObservation = Task { [weak self] in
+            for await newFavorites in stream {
+                guard let self else { break }
+                self.favoriteIds = newFavorites
             }
-            .store(in: &cancellables)
+        }
     }
 
     // MARK: - Data Loading
@@ -194,6 +204,7 @@ public class ItemsViewModel: ObservableObject {
 
     public func clearSearch() {
         searchText = ""
+        debounceTask?.cancel()
         searchTask?.cancel()
         isSearching = false
         hasError = false
diff --git a/ViewModel/Sources/ViewModel/Login/LoginViewModel.swift b/ViewModel/Sources/ViewModel/Login/LoginViewModel.swift
index 06718536..768fd012 100644
--- a/ViewModel/Sources/ViewModel/Login/LoginViewModel.swift
+++ b/ViewModel/Sources/ViewModel/Login/LoginViewModel.swift
@@ -5,14 +5,15 @@
 //  ViewModel for Login screen
 //
 
-import Combine
 import Foundation
+import Observation
 
 import FunCore
 import FunModel
 
 @MainActor
-public class LoginViewModel: ObservableObject {
+@Observable
+public class LoginViewModel {
 
     // MARK: - Navigation Closures
 
@@ -20,17 +21,17 @@ public class LoginViewModel: ObservableObject {
 
     // MARK: - Services
 
-    @Service(.logger) private var logger: LoggerService
-    @Service(.network) private var networkService: NetworkService
-    @Service(.toast) private var toastService: ToastServiceProtocol
+    @ObservationIgnored @Service(.logger) private var logger: LoggerService
+    @ObservationIgnored @Service(.network) private var networkService: NetworkService
+    @ObservationIgnored @Service(.toast) private var toastService: ToastServiceProtocol
 
-    // MARK: - Published State
+    // MARK: - State
 
-    @Published public var isLoggingIn: Bool = false
+    public var isLoggingIn: Bool = false
 
     // MARK: - Private Properties
 
-    private var loginTask: Task<Void, Never>?
+    @ObservationIgnored private var loginTask: Task<Void, Never>?
 
     // MARK: - Initialization
 
diff --git a/ViewModel/Sources/ViewModel/Profile/ProfileViewModel.swift b/ViewModel/Sources/ViewModel/Profile/ProfileViewModel.swift
index 6e89b4c4..ee85fdec 100644
--- a/ViewModel/Sources/ViewModel/Profile/ProfileViewModel.swift
+++ b/ViewModel/Sources/ViewModel/Profile/ProfileViewModel.swift
@@ -6,12 +6,14 @@
 //
 
 import Foundation
+import Observation
 
 import FunCore
 import FunModel
 
 @MainActor
-public class ProfileViewModel: ObservableObject {
+@Observable
+public class ProfileViewModel {
 
     // MARK: - Navigation Closures
 
@@ -21,16 +23,16 @@ public class ProfileViewModel: ObservableObject {
 
     // MARK: - Services
 
-    @Service(.logger) private var logger: LoggerService
+    @ObservationIgnored @Service(.logger) private var logger: LoggerService
 
-    // MARK: - Published State
+    // MARK: - State
 
-    @Published public var userName: String
-    @Published public var userEmail: String
-    @Published public var userBio: String
-    @Published public var viewCount: Int
-    @Published public var favoritesCount: Int
-    @Published public var daysCount: Int
+    public var userName: String
+    public var userEmail: String
+    public var userBio: String
+    public var viewCount: Int
+    public var favoritesCount: Int
+    public var daysCount: Int
 
     // MARK: - Initialization
 
diff --git a/ViewModel/Sources/ViewModel/Settings/SettingsViewModel.swift b/ViewModel/Sources/ViewModel/Settings/SettingsViewModel.swift
index 0c8ee299..f6beb3b1 100644
--- a/ViewModel/Sources/ViewModel/Settings/SettingsViewModel.swift
+++ b/ViewModel/Sources/ViewModel/Settings/SettingsViewModel.swift
@@ -5,45 +5,47 @@
 //  ViewModel for Settings screen
 //
 
-import Combine
 import Foundation
+import Observation
 
 import FunCore
 import FunModel
 
 @MainActor
-public class SettingsViewModel: ObservableObject {
+@Observable
+public class SettingsViewModel {
 
     // MARK: - Services
 
-    @Service(.logger) private var logger: LoggerService
-    @Service(.featureToggles) private var featureToggleService: FeatureToggleServiceProtocol
+    @ObservationIgnored @Service(.logger) private var logger: LoggerService
+    @ObservationIgnored @Service(.featureToggles) private var featureToggleService: FeatureToggleServiceProtocol
 
-    // MARK: - Published State
+    // MARK: - State
 
-    @Published public var appearanceMode: AppearanceMode = .system {
+    public var appearanceMode: AppearanceMode = .system {
         didSet { featureToggleService.appearanceMode = appearanceMode }
     }
 
-    @Published public var featuredCarouselEnabled: Bool = true {
+    public var featuredCarouselEnabled: Bool = true {
         didSet { featureToggleService.featuredCarousel = featuredCarouselEnabled }
     }
 
-    @Published public var simulateErrorsEnabled: Bool = false {
+    public var simulateErrorsEnabled: Bool = false {
         didSet { featureToggleService.simulateErrors = simulateErrorsEnabled }
     }
 
-    @Published public var aiSummaryEnabled: Bool = true {
+    public var aiSummaryEnabled: Bool = true {
         didSet { featureToggleService.aiSummary = aiSummaryEnabled }
     }
 
     // MARK: - Initialization
 
     public init() {
-        _appearanceMode = Published(initialValue: featureToggleService.appearanceMode)
-        _featuredCarouselEnabled = Published(initialValue: featureToggleService.featuredCarousel)
-        _simulateErrorsEnabled = Published(initialValue: featureToggleService.simulateErrors)
-        _aiSummaryEnabled = Published(initialValue: featureToggleService.aiSummary)
+        // Override defaults with actual service values (didSet won't fire during init)
+        appearanceMode = featureToggleService.appearanceMode
+        featuredCarouselEnabled = featureToggleService.featuredCarousel
+        simulateErrorsEnabled = featureToggleService.simulateErrors
+        aiSummaryEnabled = featureToggleService.aiSummary
     }
 
     // MARK: - Actions
diff --git a/ViewModel/Tests/ViewModelTests/DetailViewModelTests.swift b/ViewModel/Tests/ViewModelTests/DetailViewModelTests.swift
index 4c62d86e..b5e22e1d 100644
--- a/ViewModel/Tests/ViewModelTests/DetailViewModelTests.swift
+++ b/ViewModel/Tests/ViewModelTests/DetailViewModelTests.swift
@@ -20,18 +20,21 @@ struct DetailViewModelTests {
 
     // MARK: - Setup
 
+    @discardableResult
     private func setupServices(
         initialFavorites: Set<String> = [],
         aiService: MockAIService = MockAIService(),
         featureToggleService: MockFeatureToggleService = MockFeatureToggleService()
-    ) {
+    ) -> MockFavoritesService {
+        let favoritesService = MockFavoritesService(initialFavorites: initialFavorites)
         ServiceLocator.shared.reset()
         ServiceLocator.shared.register(MockLoggerService(), for: .logger)
         ServiceLocator.shared.register(MockNetworkService(), for: .network)
-        ServiceLocator.shared.register(MockFavoritesService(initialFavorites: initialFavorites), for: .favorites)
+        ServiceLocator.shared.register(favoritesService, for: .favorites)
         ServiceLocator.shared.register(featureToggleService, for: .featureToggles)
         ServiceLocator.shared.register(MockToastService(), for: .toast)
         ServiceLocator.shared.register(aiService, for: .ai)
+        return favoritesService
     }
 
     private var testItem: FeaturedItem {
@@ -78,9 +81,7 @@ struct DetailViewModelTests {
         #expect(viewModel.isFavorited == false)
 
         viewModel.didTapToggleFavorite()
-
-        // Wait for publisher to propagate
-        await Task.yield()
+        await awaitObservation { _ = viewModel.isFavorited }
 
         #expect(viewModel.isFavorited == true)
     }
@@ -94,9 +95,7 @@ struct DetailViewModelTests {
         #expect(viewModel.isFavorited == true)
 
         viewModel.didTapToggleFavorite()
-
-        // Wait for publisher to propagate
-        await Task.yield()
+        await awaitObservation { _ = viewModel.isFavorited }
 
         #expect(viewModel.isFavorited == false)
     }
@@ -105,20 +104,15 @@ struct DetailViewModelTests {
 
     @Test("ViewModel updates when favorites service changes externally")
     func testExternalFavoritesChange() async {
-        setupServices(initialFavorites: [])
-        let mockFavorites = MockFavoritesService(initialFavorites: [])
-        ServiceLocator.shared.register(mockFavorites, for: .favorites)
+        let mockFavorites = setupServices(initialFavorites: [])
 
         let item = testItem
         let viewModel = DetailViewModel(item: item)
 
         #expect(viewModel.isFavorited == false)
 
-        // Change favorites externally
         mockFavorites.addFavorite(item.id)
-
-        // Wait for publisher
-        await Task.yield()
+        await awaitObservation { _ = viewModel.isFavorited }
 
         #expect(viewModel.isFavorited == true)
     }
@@ -139,7 +133,7 @@ struct DetailViewModelTests {
     func testDifferentItems() async {
         setupServices()
 
-        let items: [FeaturedItem] = [.swiftUI, .combine, .mvvm, .coordinator]
+        let items: [FeaturedItem] = [.swiftUI, .asyncSequence, .mvvm, .coordinator]
         for item in items {
             let viewModel = DetailViewModel(item: item)
             #expect(viewModel.itemTitle == item.title)
diff --git a/ViewModel/Tests/ViewModelTests/HomeViewModelTests.swift b/ViewModel/Tests/ViewModelTests/HomeViewModelTests.swift
index ef6d7c93..eb8d1a86 100644
--- a/ViewModel/Tests/ViewModelTests/HomeViewModelTests.swift
+++ b/ViewModel/Tests/ViewModelTests/HomeViewModelTests.swift
@@ -113,10 +113,9 @@ struct HomeViewModelTests {
         // Explicitly call loadFeaturedItems and wait for it
         await viewModel.loadFeaturedItems()
 
-        // Verify the toast was called
-        let resolvedToast: MockToastService = ServiceLocator.shared.resolve(for: .toast)
-        #expect(resolvedToast.showToastCalled == true)
-        #expect(resolvedToast.lastType == .error)
+        // Verify the toast was called (use local ref, not ServiceLocator which may be reset by parallel tests)
+        #expect(mockToast.showToastCalled == true)
+        #expect(mockToast.lastType == .error)
     }
 
     // MARK: - Coordinator Tests
@@ -178,9 +177,7 @@ struct HomeViewModelTests {
         #expect(viewModel.isFavorited("test_item") == false)
 
         viewModel.toggleFavorite(for: "test_item")
-
-        // Wait for publisher to propagate
-        await Task.yield()
+        await awaitObservation { _ = viewModel.favoriteIds }
 
         #expect(viewModel.isFavorited("test_item") == true)
     }
@@ -193,9 +190,7 @@ struct HomeViewModelTests {
         #expect(viewModel.isFavorited("test_item") == true)
 
         viewModel.toggleFavorite(for: "test_item")
-
-        // Wait for publisher to propagate
-        await Task.yield()
+        await awaitObservation { _ = viewModel.favoriteIds }
 
         #expect(viewModel.isFavorited("test_item") == false)
     }
diff --git a/ViewModel/Tests/ViewModelTests/ItemsViewModelTests.swift b/ViewModel/Tests/ViewModelTests/ItemsViewModelTests.swift
index 7b771b64..c079943c 100644
--- a/ViewModel/Tests/ViewModelTests/ItemsViewModelTests.swift
+++ b/ViewModel/Tests/ViewModelTests/ItemsViewModelTests.swift
@@ -20,13 +20,19 @@ struct ItemsViewModelTests {
 
     // MARK: - Setup
 
-    private func setupServices(initialFavorites: Set<String> = [], simulateErrors: Bool = false) {
+    @discardableResult
+    private func setupServices(
+        initialFavorites: Set<String> = [],
+        simulateErrors: Bool = false
+    ) -> MockFavoritesService {
+        let favoritesService = MockFavoritesService(initialFavorites: initialFavorites)
         ServiceLocator.shared.reset()
         ServiceLocator.shared.register(MockLoggerService(), for: .logger)
         ServiceLocator.shared.register(MockNetworkService(shouldThrowError: simulateErrors), for: .network)
-        ServiceLocator.shared.register(MockFavoritesService(initialFavorites: initialFavorites), for: .favorites)
+        ServiceLocator.shared.register(favoritesService, for: .favorites)
         ServiceLocator.shared.register(MockFeatureToggleService(simulateErrors: simulateErrors), for: .featureToggles)
         ServiceLocator.shared.register(MockToastService(), for: .toast)
+        return favoritesService
     }
 
     // MARK: - Initialization Tests
@@ -166,9 +172,7 @@ struct ItemsViewModelTests {
         #expect(viewModel.isFavorited("test_item") == false)
 
         viewModel.toggleFavorite(for: "test_item")
-
-        // Wait for publisher to propagate
-        await Task.yield()
+        await awaitObservation { _ = viewModel.favoriteIds }
 
         #expect(viewModel.isFavorited("test_item") == true)
     }
@@ -181,9 +185,7 @@ struct ItemsViewModelTests {
         #expect(viewModel.isFavorited("test_item") == true)
 
         viewModel.toggleFavorite(for: "test_item")
-
-        // Wait for publisher to propagate
-        await Task.yield()
+        await awaitObservation { _ = viewModel.favoriteIds }
 
         #expect(viewModel.isFavorited("test_item") == false)
     }
@@ -192,19 +194,14 @@ struct ItemsViewModelTests {
 
     @Test("ViewModel updates favoriteIds when service changes")
     func testViewModelObservesFavoritesChanges() async {
-        setupServices(initialFavorites: [])
-        let mockFavorites = MockFavoritesService(initialFavorites: [])
-        ServiceLocator.shared.register(mockFavorites, for: .favorites)
+        let mockFavorites = setupServices(initialFavorites: [])
 
         let viewModel = ItemsViewModel()
 
         #expect(viewModel.favoriteIds.isEmpty)
 
-        // Add favorite directly on the service
         mockFavorites.addFavorite("new_item")
-
-        // Wait for publisher to propagate
-        await Task.yield()
+        await awaitObservation { _ = viewModel.favoriteIds }
 
         #expect(viewModel.favoriteIds.contains("new_item"))
     }
@@ -272,7 +269,7 @@ struct ItemsViewModelTests {
     // MARK: - Network Search Tests
 
     @Test("Search calls networkService.searchItems with query and category")
-    func testSearchCallsNetworkService() async throws {
+    func testSearchCallsNetworkService() async {
         setupServices()
         let mockNetwork = MockNetworkService(
             stubbedSearchItems: [.swiftUI]
@@ -284,9 +281,7 @@ struct ItemsViewModelTests {
         viewModel.searchText = "swift"
         // Trigger search directly by calling the debounced path
         viewModel.didSelectCategory(viewModel.selectedCategory)
-
-        // Wait for the search task to complete
-        try await Task.sleep(for: .milliseconds(100))
+        await awaitObservation { _ = viewModel.isSearching }
 
         #expect(mockNetwork.searchItemsCallCount == 1)
         #expect(mockNetwork.lastSearchQuery == "swift")
@@ -296,28 +291,28 @@ struct ItemsViewModelTests {
     }
 
     @Test("Search error sets hasError and shows toast")
-    func testSearchErrorSetsHasError() async throws {
+    func testSearchErrorSetsHasError() async {
         setupServices()
         let mockNetwork = MockNetworkService(shouldThrowError: true)
+        let mockToast = MockToastService()
         ServiceLocator.shared.register(mockNetwork, for: .network)
+        ServiceLocator.shared.register(mockToast, for: .toast)
         let viewModel = ItemsViewModel()
 
         viewModel.searchText = "swift"
         viewModel.didSelectCategory(viewModel.selectedCategory)
-
-        try await Task.sleep(for: .milliseconds(100))
+        await awaitObservation { _ = viewModel.isSearching }
 
         #expect(viewModel.hasError == true)
         #expect(viewModel.items.isEmpty)
         #expect(viewModel.isSearching == false)
 
-        let mockToast: ToastServiceProtocol = ServiceLocator.shared.resolve(for: .toast)
-        let toast = mockToast as! MockToastService
-        #expect(toast.showToastCalled == true)
+        // Use local ref, not ServiceLocator which may be reset by parallel tests
+        #expect(mockToast.showToastCalled == true)
     }
 
     @Test("Clear search resets to filtered allItems")
-    func testClearSearchResetsToAllItems() async throws {
+    func testClearSearchResetsToAllItems() async {
         setupServices()
         let mockNetwork = MockNetworkService(
             stubbedSearchItems: [.swiftUI]
@@ -331,7 +326,7 @@ struct ItemsViewModelTests {
         // Perform a search
         viewModel.searchText = "swift"
         viewModel.didSelectCategory(viewModel.selectedCategory)
-        try await Task.sleep(for: .milliseconds(100))
+        await awaitObservation { _ = viewModel.isSearching }
         #expect(viewModel.items.count == 1)
 
         // Clear search
diff --git a/ViewModel/Tests/ViewModelTests/ViewModelTestSuite.swift b/ViewModel/Tests/ViewModelTests/ViewModelTestSuite.swift
index df448a4f..961c9061 100644
--- a/ViewModel/Tests/ViewModelTests/ViewModelTestSuite.swift
+++ b/ViewModel/Tests/ViewModelTests/ViewModelTestSuite.swift
@@ -7,7 +7,20 @@
 //
 
 import Testing
+import Observation
 
 @Suite("ViewModel Tests", .serialized)
 @MainActor
 struct ViewModelTestSuite {}
+
+/// Yields the MainActor until an observed @Observable property changes.
+/// Call AFTER triggering the action — @MainActor serialization ensures
+/// the observation task can't run until we suspend at withCheckedContinuation.
+@MainActor
+func awaitObservation(_ apply: () -> Void) async {
+    await withCheckedContinuation { continuation in
+        withObservationTracking(apply) {
+            continuation.resume()
+        }
+    }
+}
diff --git a/ai-rules/general.md b/ai-rules/general.md
index 75f92f30..b52ca164 100644
--- a/ai-rules/general.md
+++ b/ai-rules/general.md
@@ -1,4 +1,4 @@
-# Fun-iOS Architecture Reference (feature/navigation-stack)
+# Fun-iOS Architecture Reference (feature/observation)
 
 ## SPM Package Structure
 
@@ -8,10 +8,10 @@
 FunApp/FunApp.xcodeproj    → iOS app target (FunApp.swift @main, AppSessionFactory)
 Coordinator/               → FunCoordinator (single AppCoordinator + views)
 UI/                        → FunUI (SwiftUI views)
-ViewModel/                 → FunViewModel (business logic, @Published state)
+ViewModel/                 → FunViewModel (business logic, @Observable-compatible state)
 Model/                     → FunModel + FunModelTestSupport (domain types, protocols, mocks)
 Services/                  → FunServices (concrete service implementations)
-Core/                      → FunCore (DI container, Session protocol, utilities)
+Core/                      → FunCore (DI container, Session protocol, StreamBroadcaster, utilities)
 ```
 
 ### Dependency Graph
@@ -35,28 +35,64 @@ FunServices
 
 Services is a sibling to the UI stack — it depends on Model and Core but NOT on ViewModel, UI, or Coordinator.
 
-## MVVM-C Architecture (NavigationStack Variant)
+## MVVM-C Architecture (AsyncSequence Variant)
 
-### Single AppCoordinator
-Unlike the main branch (6 UIKit coordinators), this branch uses a **single `AppCoordinator: ObservableObject`** that manages all navigation state:
+### Single @Observable AppCoordinator
+This branch uses `@Observable` (not ObservableObject) with `@ObservationIgnored` for non-observed state:
 
 ```swift
 @MainActor
-public final class AppCoordinator: ObservableObject {
-    @Published public var currentFlow: AppFlow = .login
-    @Published public var selectedTab: TabIndex = .home
-    @Published public var homePath = NavigationPath()
-    @Published public var itemsPath = NavigationPath()
-    @Published public var settingsPath = NavigationPath()
-    @Published public var isProfilePresented = false
-    @Published public var activeToast: ToastEvent?
-    @Published public var appearanceMode: AppearanceMode = .system
+@Observable
+public final class AppCoordinator {
+    // Observed by SwiftUI
+    public var currentFlow: AppFlow = .login
+    public var selectedTab: TabIndex = .home
+    public var homePath = NavigationPath()
+    public var itemsPath = NavigationPath()
+    public var settingsPath = NavigationPath()
+    public var isProfilePresented = false
+    public var activeToast: ToastEvent?
+    public var appearanceMode: AppearanceMode = .system
+
+    // Not observed
+    @ObservationIgnored @Service(.logger) private var logger: LoggerService
+    @ObservationIgnored private let sessionFactory: SessionFactory
+    @ObservationIgnored private var currentSession: Session?
+    @ObservationIgnored private var pendingDeepLink: DeepLink?
+    @ObservationIgnored private var toastObservation: Task<Void, Never>?
+}
+```
+
+### StreamBroadcaster (in FunCore)
+Replaces Combine's Subject pattern. One-to-many AsyncStream broadcaster:
+```swift
+@MainActor
+public final class StreamBroadcaster<Element: Sendable> {
+    func makeStream() -> AsyncStream<Element>  // Each consumer gets independent stream
+    func yield(_ value: Element)                // Broadcast to all consumers
+    func finish()                               // Complete all streams
+}
+```
+
+Services use `StreamBroadcaster` to emit events. Consumers iterate with `for await`:
+```swift
+// In service
+private let broadcaster = StreamBroadcaster<ToastEvent>()
+func makeStream() -> AsyncStream<ToastEvent> { broadcaster.makeStream() }
+
+// In coordinator/viewmodel
+Task { [weak self] in
+    let stream = toastService.makeStream()
+    for await event in stream {
+        guard let self else { return }
+        self.activeToast = event
+    }
 }
 ```
 
 ### Navigation Architecture
 ```
-FunApp (@main)
+FunApp (@main, uses @State not @StateObject)
   └─ AppRootView
        ├─ LoginTabContent (when currentFlow == .login)
        └─ MainTabView (when currentFlow == .main)
@@ -71,11 +107,10 @@ FunApp (@main)
 ```
 
 ### View Wiring Pattern (this branch)
-Tab content wrappers create ViewModels and wire closures:
 ```swift
 struct HomeTabContent: View {
     let coordinator: AppCoordinator
-    @StateObject private var viewModel = HomeViewModel()
+    @State private var viewModel = HomeViewModel()  // @State, not @StateObject
 
     var body: some View {
         HomeView(viewModel: viewModel)
@@ -93,7 +128,8 @@ struct HomeTabContent: View {
 
 ## ServiceLocator & @Service
 
-Same as main branch — `ServiceLocator.shared` with `@Service` property wrapper.
+Same as other branches — `ServiceLocator.shared` with `@Service` property wrapper.
+Service events use `StreamBroadcaster` instead of Combine publishers.
 
 ### Service Keys
 `ServiceKey` enum in Core: `.network`, `.logger`, `.favorites`, `.toast`, `.featureToggles`, `.ai`
@@ -106,13 +142,13 @@ Same as main branch — `ServiceLocator.shared` with `@Service` property wrapper
 | `AuthenticatedSession` | logger, network, favorites, toast, featureToggles, ai | Main app |
 
 - `AppSessionFactory` creates the right session for each `AppFlow` case
-- App entry (`FunApp.swift`) creates coordinator with `@StateObject` and calls `.start()` in `.task`
+- App entry (`FunApp.swift`) creates coordinator with `@State` and calls `.start()` in `.task`
 
 ## Protocol Placement
 
 | Package | What goes here | Example |
 |---|---|---|
-| Core | Reusable abstractions not tied to domain | `Session`, `ServiceLocator`, `@Service` |
+| Core | Reusable abstractions not tied to domain | `Session`, `ServiceLocator`, `@Service`, `StreamBroadcaster` |
 | Model | Domain-specific protocols and types | `LoggerService`, `FavoritesServiceProtocol`, `NetworkService`, `SessionFactory`, `DeepLink`, `AppFlow`, `TabIndex` |
 | Services | Concrete implementations only | `DefaultLoggerService`, `LoginSession`, `AuthenticatedSession` |
 
@@ -137,8 +173,14 @@ App entry uses `.onOpenURL { url in coordinator.handleDeepLink(DeepLink(url: url
 - **Test support import**: `@testable import FunModelTestSupport`
 - **Snapshots**: swift-snapshot-testing in UI package tests
 
-## Key Difference from Main Branch
+## Key Differences from Other Branches
 - No UIKit, no UIViewControllers, no UIHostingController, no BaseCoordinator
 - Single coordinator (not 6 separate ones)
 - Navigation via NavigationPath (declarative) instead of safePush/safePop (imperative)
 - App entry via SwiftUI @main, not SceneDelegate
+- `@Observable` instead of `ObservableObject` — no `@Published`, SwiftUI tracks property access automatically
+- `@ObservationIgnored` for services and private state that shouldn't trigger view updates
+- `@State` instead of `@StateObject` for coordinator and viewmodel ownership
+- `StreamBroadcaster` replaces Combine publishers — `for await` instead of `.sink`
+- `Task` for observation instead of `AnyCancellable` — cancel via `task?.cancel()`
+- Zero `import Combine` in the entire codebase
diff --git a/ai-rules/swift-style.md b/ai-rules/swift-style.md
index c9bbfbe0..c86da447 100644
--- a/ai-rules/swift-style.md
+++ b/ai-rules/swift-style.md
@@ -1,74 +1,114 @@
-# Swift Style Guide — Fun-iOS (feature/navigation-stack)
+# Swift Style Guide — Fun-iOS (feature/observation)
 
 ## Swift 6 Strict Concurrency
 
 ### Actor Isolation
-- `@MainActor` on AppCoordinator, all ViewModels, ServiceLocator, Session implementations
+- `@MainActor` on AppCoordinator, all ViewModels, ServiceLocator, Session implementations, StreamBroadcaster
 - `Sendable` conformance on value types crossing isolation boundaries
 - `nonisolated` only when a method genuinely doesn't touch actor-isolated state
 
 ### Self-Capture in Async Closures
 - **Default to `self?.`** for ViewModel async work — if self is nil, the view is gone anyway
 - `guard let self` creates a strong local ref that keeps self alive across `await` suspension points
-- For `AsyncSequence` loops, `guard let self` must go INSIDE the loop body
+- For `for await` loops, `guard let self` must go INSIDE the loop body, not before the `for await`
 - Zero `[unowned self]` in this codebase — never introduce it
 - **`[weak coordinator]`** in tab content wrappers when wiring closures
+- **`[weak self]`** in Task closures that observe streams
 
 ### Sendable Types
 - All enums in Model are `Sendable` (`AppFlow`, `TabIndex`, `DeepLink`, `AppearanceMode`, etc.)
 - Protocols that cross isolation boundaries include `Sendable` conformance
+- `StreamBroadcaster<Element: Sendable>` — element type must be Sendable
 
-## MVVM-C Patterns
+## @Observable Patterns (this branch)
+
+### @Observable vs ObservableObject
+This branch uses Swift Observation framework, NOT Combine's ObservableObject:
+- **Use `@Observable`** on coordinator and viewmodel classes (not `ObservableObject`)
+- **No `@Published`** — just regular `var` properties, SwiftUI tracks access automatically
+- **Use `@ObservationIgnored`** for services, private state, and anything that shouldn't trigger view updates
+- **Use `@State`** (not `@StateObject`) to own @Observable objects in views
+- **No `@ObservedObject`** — just pass @Observable objects directly
 
 ### ViewModels
-- `@MainActor` class conforming to `ObservableObject`
-- `@Published` properties for view state
+- `@MainActor @Observable` class
+- Regular `var` properties for view state (SwiftUI auto-tracks)
+- `@ObservationIgnored` for services (`@Service` properties) and non-UI state
 - Optional closures for navigation: `var onShowDetail: ((FeaturedItem) -> Void)?`
-- Services accessed via `@Service` property wrapper
-- Private `Set<AnyCancellable>` for Combine subscriptions
+- `Task` for stream observation, stored as `@ObservationIgnored private var observationTask: Task<Void, Never>?`
 - No UIKit imports. No coordinator references.
 
-### Views (Pure SwiftUI)
-- Observe ViewModel via `@ObservedObject` or `@StateObject`
+### Views — Passing @Observable Objects
+- **`let` / `var`** — when you only **read** properties (e.g. `coordinator.currentFlow`)
+- **`@Bindable`** — when you need **`$` bindings** (e.g. `$coordinator.selectedTab`, `$coordinator.isProfilePresented`)
+- **`@State`** — when the view **owns** the object (e.g. tab content wrappers owning their ViewModel)
+- Rule of thumb: if you see a `$` in the body, you need `@Bindable`. Otherwise plain property.
 - Never make navigation decisions — call ViewModel methods which invoke closures
 - No `import UIKit` anywhere in this branch
 
 ### AppCoordinator
-- Single `ObservableObject` managing all navigation state
-- `@Published` NavigationPath per tab + selectedTab + modal flags
-- Created with `@StateObject` in the app entry point
+- `@MainActor @Observable` with per-tab NavigationPath
+- `@ObservationIgnored` for sessionFactory, currentSession, pendingDeepLink, observation Tasks
+- Created with `@State` in the app entry point
 - Tab content wrappers wire ViewModel closures using `[weak coordinator]`
 
-## Combine Patterns (this branch)
-
-### Publishers
-- `@Published` in AppCoordinator for navigation state
-- `@Published` in ViewModels for UI-bound state
-- `CurrentValueSubject` / `PassthroughSubject` in services for events
-- `serviceDidRegisterPublisher` on ServiceLocator for dynamic registration
-
-### Schedulers
-- `RunLoop.main` for `debounce`/`throttle` — cooperates with `Task.sleep` in async tests
-- `DispatchQueue.main` for `receive(on:)` — not affected by scroll tracking mode
-- If subscriber is already `@MainActor`, `receive(on:)` is redundant — skip it
-
-### Subscriptions
-- Store in `private var cancellables = Set<AnyCancellable>()`
-- Use `[weak self]` in `.sink` closures
+## AsyncSequence Patterns (this branch — zero Combine)
+
+### StreamBroadcaster
+Central pattern replacing Combine publishers. Located in `Core/Sources/Core/StreamBroadcaster.swift`:
+```swift
+// Service exposes a stream factory
+func makeStream() -> AsyncStream<ToastEvent> {
+    broadcaster.makeStream()
+}
+
+// Consumer iterates
+Task { [weak self] in
+    for await event in service.makeStream() {
+        guard let self else { return }
+        self.handleEvent(event)
+    }
+}
+```
+
+### Stream Observation Lifecycle
+- Start observation in `start()` or initialization methods
+- Store the `Task` for cancellation: `observationTask = Task { ... }`
+- Cancel in cleanup: `observationTask?.cancel()`
+- Always use `[weak self]` in Task closures
+- Always `guard let self` INSIDE `for await` loops
+
+### ServiceLocator Registration Events
+`serviceRegistrations` property returns `AsyncStream<ServiceKey>` (replaces Combine's `serviceDidRegisterPublisher`):
+```swift
+Task { [weak self] in
+    for await key in ServiceLocator.shared.serviceRegistrations {
+        if key == .featureToggles {
+            self?.observeFeatureToggles()
+        }
+    }
+}
+```
 
 ## Naming Conventions
 
 ### Types
-- AppCoordinator (single, not per-tab)
+- AppCoordinator (single, @Observable)
 - Tab content wrappers: `HomeTabContent`, `ItemsTabContent`, `SettingsTabContent`, `ProfileTabContent`, `LoginTabContent`
-- ViewModels: `HomeViewModel`, `ItemsViewModel`, `DetailViewModel`
-- Views: `HomeView`, `ItemsView`, `DetailView`
+- ViewModels: `HomeViewModel`, `ItemsViewModel`, `DetailViewModel` (@Observable)
+- Views: `HomeView`, `ItemsView`, `DetailView` (pure SwiftUI)
 - Services: protocol `FavoritesServiceProtocol`, impl `DefaultFavoritesService`
 
 ### Navigation Closures
 - `onShowDetail`, `onShowProfile`, `onLoginSuccess`, `onLogout`, `onDismiss`, `onGoToItems`
 - Always optional, wired in tab content wrapper `.task` blocks
 
+### Task Properties
+- `private var toastObservation: Task<Void, Never>?`
+- `private var darkModeObservation: Task<Void, Never>?`
+- `private var registrationObservation: Task<Void, Never>?`
+- `private var loadTask: Task<Void, Never>?`
+
 ## SwiftLint Rules
 
 Zero-tolerance — CI fails on any violation.
@@ -100,3 +140,12 @@ Zero-tolerance — CI fails on any violation.
 | Is only needed by one implementation | Probably don't need a protocol |
 
 Never define protocols in `Services`, `ViewModel`, `UI`, or `Coordinator`.
+
+## Things That Don't Belong in This Branch
+- `import Combine` — use AsyncSequence/StreamBroadcaster instead
+- `@Published` — use regular `var` with `@Observable`
+- `ObservableObject` — use `@Observable`
+- `@StateObject` — use `@State`
+- `@ObservedObject` — pass @Observable objects directly
+- `AnyCancellable` / `Set<AnyCancellable>` — use Task cancellation
+- `CurrentValueSubject` / `PassthroughSubject` — use StreamBroadcaster