Update the SDK.

Handles changes that removed support for the sliding sync proxy.
2026-11-04 01:20:12 +00:00 · 2025-02-18 10:34:32 +00:00
parent f77faee981
commit 8c07ee35c4
33 changed files with 229 additions and 309 deletions
@@ -120,6 +120,7 @@
 "action_yes" = "Yes";
 "action_yes_try_again" = "Yes, try again";
 "banner_migrate_to_native_sliding_sync_action" = "Log Out & Upgrade";
+"banner_migrate_to_native_sliding_sync_app_force_logout_title" = "Element X no longer supports the old protocol. Please log out and log back in to continue using the app.";
 "banner_migrate_to_native_sliding_sync_description" = "Your server now supports a new, faster protocol. Log out and log back in to upgrade now. Doing this now will help you avoid a forced logout when the old protocol is removed later.";
 "banner_migrate_to_native_sliding_sync_force_logout_title" = "Your homeserver no longer supports the old protocol. Please log out and log back in to continue using the app.";
 "banner_migrate_to_native_sliding_sync_title" = "Upgrade available";
@@ -120,6 +120,7 @@
 "action_yes" = "Yes";
 "action_yes_try_again" = "Yes, try again";
 "banner_migrate_to_native_sliding_sync_action" = "Log Out & Upgrade";
+"banner_migrate_to_native_sliding_sync_app_force_logout_title" = "Element X no longer supports the old protocol. Please log out and log back in to continue using the app.";
 "banner_migrate_to_native_sliding_sync_description" = "Your server now supports a new, faster protocol. Log out and log back in to upgrade now. Doing this now will help you avoid a forced logout when the old protocol is removed later.";
 "banner_migrate_to_native_sliding_sync_force_logout_title" = "Your homeserver no longer supports the old protocol. Please log out and log back in to continue using the app.";
 "banner_migrate_to_native_sliding_sync_title" = "Upgrade available";
@@ -44,7 +44,6 @@ final class AppSettings {
        case elementCallBaseURLOverride
        
        // Feature flags
-        case slidingSyncDiscovery
        case publicSearchEnabled
        case fuzzyRoomListSearchEnabled
        case enableOnlySignedDeviceIsolationMode
@@ -283,10 +282,6 @@ final class AppSettings {
    @UserPreference(key: UserDefaultsKeys.fuzzyRoomListSearchEnabled, defaultValue: false, storageType: .userDefaults(store))
    var fuzzyRoomListSearchEnabled
    
-    enum SlidingSyncDiscovery: Codable { case proxy, native, forceNative }
-    @UserPreference(key: UserDefaultsKeys.slidingSyncDiscovery, defaultValue: .native, storageType: .userDefaults(store))
-    var slidingSyncDiscovery: SlidingSyncDiscovery
-    
    @UserPreference(key: UserDefaultsKeys.knockingEnabled, defaultValue: false, storageType: .userDefaults(store))
    var knockingEnabled
    
@@ -230,7 +230,7 @@ class SettingsFlowCoordinator: FlowCoordinatorProtocol {
    }
    
    private func presentDeveloperOptions() {
-        let coordinator = DeveloperOptionsScreenCoordinator(isUsingNativeSlidingSync: parameters.userSession.clientProxy.slidingSyncVersion == .native)
+        let coordinator = DeveloperOptionsScreenCoordinator()
        
        coordinator.actions
            .sink { [weak self] action in
@@ -274,6 +274,8 @@ internal enum L10n {
  internal static var actionYesTryAgain: String { return L10n.tr("Localizable", "action_yes_try_again") }
  /// Log Out & Upgrade
  internal static var bannerMigrateToNativeSlidingSyncAction: String { return L10n.tr("Localizable", "banner_migrate_to_native_sliding_sync_action") }
+  /// Element X no longer supports the old protocol. Please log out and log back in to continue using the app.
+  internal static var bannerMigrateToNativeSlidingSyncAppForceLogoutTitle: String { return L10n.tr("Localizable", "banner_migrate_to_native_sliding_sync_app_force_logout_title") }
  /// Your server now supports a new, faster protocol. Log out and log back in to upgrade now. Doing this now will help you avoid a forced logout when the old protocol is removed later.
  internal static var bannerMigrateToNativeSlidingSyncDescription: String { return L10n.tr("Localizable", "banner_migrate_to_native_sliding_sync_description") }
  /// Your homeserver no longer supports the old protocol. Please log out and log back in to continue using the app.
@@ -69,10 +69,8 @@ extension ClientProxyMock {
        ignoreUserReturnValue = .success(())
        unignoreUserReturnValue = .success(())
        
+        needsSlidingSyncMigration = false
        slidingSyncVersion = .native
-        availableSlidingSyncVersionsClosure = {
-            []
-        }
        
        trackRecentlyVisitedRoomReturnValue = .success(())
        recentlyVisitedRoomsReturnValue = .success([])
@@ -2235,28 +2235,16 @@ class ClientProxyMock: ClientProxyProtocol, @unchecked Sendable {
        set(value) { underlyingHomeserver = value }
    }
    var underlyingHomeserver: String!
+    var needsSlidingSyncMigration: Bool {
+        get { return underlyingNeedsSlidingSyncMigration }
+        set(value) { underlyingNeedsSlidingSyncMigration = value }
+    }
+    var underlyingNeedsSlidingSyncMigration: Bool!
    var slidingSyncVersion: SlidingSyncVersion {
        get { return underlyingSlidingSyncVersion }
        set(value) { underlyingSlidingSyncVersion = value }
    }
    var underlyingSlidingSyncVersion: SlidingSyncVersion!
-    var availableSlidingSyncVersionsCallsCount = 0
-    var availableSlidingSyncVersionsCalled: Bool {
-        return availableSlidingSyncVersionsCallsCount > 0
-    }
-
-    var availableSlidingSyncVersions: [SlidingSyncVersion] {
-        get async {
-            availableSlidingSyncVersionsCallsCount += 1
-            if let availableSlidingSyncVersionsClosure = availableSlidingSyncVersionsClosure {
-                return await availableSlidingSyncVersionsClosure()
-            } else {
-                return underlyingAvailableSlidingSyncVersions
-            }
-        }
-    }
-    var underlyingAvailableSlidingSyncVersions: [SlidingSyncVersion]!
-    var availableSlidingSyncVersionsClosure: (() async -> [SlidingSyncVersion])?
    var canDeactivateAccount: Bool {
        get { return underlyingCanDeactivateAccount }
        set(value) { underlyingCanDeactivateAccount = value }
@@ -27,9 +27,7 @@ extension ClientBuilder {
        
        builder = switch slidingSync {
        case .restored: builder
-        case .discoverProxy: builder.slidingSyncVersionBuilder(versionBuilder: .discoverProxy)
-        case .discoverNative: builder.slidingSyncVersionBuilder(versionBuilder: .discoverNative)
-        case .forceNative: builder.slidingSyncVersionBuilder(versionBuilder: .native)
+        case .discover: builder.slidingSyncVersionBuilder(versionBuilder: .discoverNative)
        }
        
        if setupEncryption {
@@ -58,12 +56,8 @@ extension ClientBuilder {
 }

 enum ClientBuilderSlidingSync {
-    /// The proxy will be supplied when restoring the Session.
+    /// Sliding sync will be configured when restoring the Session.
    case restored
-    /// A proxy must be discovered whilst building the session.
-    case discoverProxy
-    /// Native sliding sync must be discovered whilst building the session.
-    case discoverNative
-    /// Forces native sliding sync without discovering it.
-    case forceNative
+    /// Sliding sync must be discovered whilst building the session.
+    case discover
 }
@@ -36,8 +36,6 @@ enum HomeScreenViewAction {
    case confirmRecoveryKey
    case resetEncryption
    case skipRecoveryKeyConfirmation
-    case confirmSlidingSyncUpgrade
-    case skipSlidingSyncUpgrade
    case updateVisibleItemRange(Range<Int>)
    case globalSearch
    case markRoomAsUnread(roomIdentifier: String)
@@ -86,17 +84,12 @@ enum HomeScreenSecurityBannerMode: Equatable {
    }
 }

-enum HomeScreenMigrationBannerMode {
-    case none, show, dismissed
-}
-
 struct HomeScreenViewState: BindableState {
    let userID: String
    var userDisplayName: String?
    var userAvatarURL: URL?
    
    var securityBannerMode = HomeScreenSecurityBannerMode.none
-    var slidingSyncMigrationBannerMode = HomeScreenMigrationBannerMode.none
    
    var requiresExtraAccountSetup = false
        
@@ -145,11 +145,6 @@ class HomeScreenViewModel: HomeScreenViewModelType, HomeScreenViewModelProtocol
            actionsSubject.send(.presentEncryptionResetScreen)
        case .skipRecoveryKeyConfirmation:
            state.securityBannerMode = .dismissed
-        case .confirmSlidingSyncUpgrade:
-            appSettings.slidingSyncDiscovery = .native
-            actionsSubject.send(.logout)
-        case .skipSlidingSyncUpgrade:
-            state.slidingSyncMigrationBannerMode = .dismissed
        case .updateVisibleItemRange(let range):
            roomSummaryProvider?.updateVisibleRange(range)
        case .startChat:
@@ -307,30 +302,18 @@ class HomeScreenViewModel: HomeScreenViewModelType, HomeScreenViewModelProtocol
    /// Check whether we can inform the user about potential migrations
    /// or have him logout as his proxy is no longer available
    private func checkSlidingSyncMigration() async {
-        // Not logged in with a proxy, don't need to do anything
-        guard userSession.clientProxy.slidingSyncVersion.isProxy else {
+        guard userSession.clientProxy.needsSlidingSyncMigration else {
            return
        }
        
-        let versions = await userSession.clientProxy.availableSlidingSyncVersions
-        
-        // Native not available, nothing we can do
-        guard versions.contains(.native) else {
-            return
-        }
-        
-        if versions.contains(where: \.isProxy) { // Both available, prompt for migration
-            state.slidingSyncMigrationBannerMode = .show
-        } else { // The proxy has been removed and logout is needed
-            // Delay setting the alert otherwise it automatically gets dismissed. Same as the crashed last run one
-            DispatchQueue.main.asyncAfter(deadline: .now() + 0.5) {
-                self.state.bindings.alertInfo = AlertInfo(id: UUID(),
-                                                          title: L10n.bannerMigrateToNativeSlidingSyncForceLogoutTitle,
-                                                          primaryButton: .init(title: L10n.bannerMigrateToNativeSlidingSyncAction) { [weak self] in
-                                                              self?.appSettings.slidingSyncDiscovery = .native
-                                                              self?.actionsSubject.send(.logoutWithoutConfirmation)
-                                                          })
-            }
+        // The proxy is no longer supported so a logout is needed.
+        // Delay setting the alert otherwise it automatically gets dismissed. Same as the crashed last run one
+        DispatchQueue.main.asyncAfter(deadline: .now() + 0.5) {
+            self.state.bindings.alertInfo = AlertInfo(id: UUID(),
+                                                      title: L10n.bannerMigrateToNativeSlidingSyncAppForceLogoutTitle,
+                                                      primaryButton: .init(title: L10n.bannerMigrateToNativeSlidingSyncAction) { [weak self] in
+                                                          self?.actionsSubject.send(.logoutWithoutConfirmation)
+                                                      })
        }
    }
    
@@ -460,14 +443,3 @@ class HomeScreenViewModel: HomeScreenViewModelType, HomeScreenViewModelProtocol
                                         message: L10n.errorUnknown)
    }
 }
-
-extension SlidingSyncVersion {
-    var isProxy: Bool {
-        switch self {
-        case .proxy:
-            return true
-        default:
-            return false
-        }
-    }
-}
@@ -119,17 +119,13 @@ struct HomeScreenContent: View {
    @ViewBuilder
    private var topSection: some View {
        // An empty VStack causes glitches within the room list
-        if context.viewState.shouldShowFilters ||
-            context.viewState.securityBannerMode.isShown ||
-            context.viewState.slidingSyncMigrationBannerMode == .show {
+        if context.viewState.shouldShowFilters || context.viewState.securityBannerMode.isShown {
            VStack(spacing: 0) {
                if context.viewState.shouldShowFilters {
                    RoomListFiltersView(state: $context.filtersState)
                }
            
-                if context.viewState.slidingSyncMigrationBannerMode == .show {
-                    HomeScreenSlidingSyncMigrationBanner(context: context)
-                } else if case let .show(state) = context.viewState.securityBannerMode {
+                if case let .show(state) = context.viewState.securityBannerMode {
                    HomeScreenRecoveryKeyConfirmationBanner(state: state, context: context)
                }
            }
@@ -1,68 +0,0 @@
-//
-// Copyright 2024 New Vector Ltd.
-//
-// SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
-// Please see LICENSE files in the repository root for full details.
-//
-
-import Combine
-import SwiftUI
-
-struct HomeScreenSlidingSyncMigrationBanner: View {
-    var context: HomeScreenViewModel.Context
-    
-    var body: some View {
-        VStack(alignment: .leading, spacing: 16) {
-            VStack(alignment: .leading, spacing: 4) {
-                HStack(spacing: 16) {
-                    Text(L10n.bannerMigrateToNativeSlidingSyncTitle)
-                        .font(.compound.bodyLGSemibold)
-                        .foregroundColor(.compound.textPrimary)
-                    
-                    Spacer()
-                    
-                    Button {
-                        context.send(viewAction: .skipSlidingSyncUpgrade)
-                    } label: {
-                        Image(systemName: "xmark")
-                            .foregroundColor(.compound.iconSecondary)
-                            .frame(width: 12, height: 12)
-                    }
-                }
-                Text(L10n.bannerMigrateToNativeSlidingSyncDescription)
-                    .font(.compound.bodyMD)
-                    .foregroundColor(.compound.textSecondary)
-            }
-            
-            Button(L10n.bannerMigrateToNativeSlidingSyncAction) {
-                context.send(viewAction: .confirmSlidingSyncUpgrade)
-            }
-            .frame(maxWidth: .infinity)
-            .buttonStyle(.compound(.primary, size: .medium))
-        }
-        .padding(16)
-        .background(Color.compound.bgSubtleSecondary)
-        .cornerRadius(14)
-        .padding(.horizontal, 16)
-    }
-}
-
-struct HomeScreenSlidingSyncMigrationBanner_Previews: PreviewProvider, TestablePreview {
-    static let viewModel = buildViewModel()
-    
-    static var previews: some View {
-        HomeScreenSlidingSyncMigrationBanner(context: viewModel.context)
-    }
-    
-    static func buildViewModel() -> HomeScreenViewModel {
-        let clientProxy = ClientProxyMock(.init())
-        
-        let userSession = UserSessionMock(.init(clientProxy: clientProxy))
-        
-        return HomeScreenViewModel(userSession: userSession,
-                                   analyticsService: ServiceLocator.shared.analytics,
-                                   appSettings: ServiceLocator.shared.settings,
-                                   selectedRoomPublisher: CurrentValueSubject<String?, Never>(nil).asCurrentValuePublisher(),
-                                   userIndicatorController: ServiceLocator.shared.userIndicatorController)
-    }
-}
@@ -22,10 +22,9 @@ final class DeveloperOptionsScreenCoordinator: CoordinatorProtocol {
        actionsSubject.eraseToAnyPublisher()
    }
    
-    init(isUsingNativeSlidingSync: Bool) {
+    init() {
        viewModel = DeveloperOptionsScreenViewModel(developerOptions: ServiceLocator.shared.settings,
-                                                    elementCallBaseURL: ServiceLocator.shared.settings.elementCallBaseURL,
-                                                    isUsingNativeSlidingSync: isUsingNativeSlidingSync)
+                                                    elementCallBaseURL: ServiceLocator.shared.settings.elementCallBaseURL)
        
        viewModel.actions
            .sink { [weak self] action in
@@ -13,12 +13,7 @@ enum DeveloperOptionsScreenViewModelAction {

 struct DeveloperOptionsScreenViewState: BindableState {
    let elementCallBaseURL: URL
-    let isUsingNativeSlidingSync: Bool
    var bindings: DeveloperOptionsScreenViewStateBindings
-    
-    var slidingSyncFooter: String {
-        "The method used to configure sliding sync when signing in. Changing this setting has no effect until you sign out.\n\nYour current session is using \(isUsingNativeSlidingSync ? "native sliding sync." : "a sliding sync proxy.")"
-    }
 }

 // periphery: ignore - subscripts are seen as false positive
@@ -42,7 +37,6 @@ enum DeveloperOptionsScreenViewAction {

 protocol DeveloperOptionsProtocol: AnyObject {
    var logLevel: LogLevel { get set }
-    var slidingSyncDiscovery: AppSettings.SlidingSyncDiscovery { get set }
    var publicSearchEnabled: Bool { get set }
    var hideUnreadMessagesBadge: Bool { get set }
    var fuzzyRoomListSearchEnabled: Bool { get set }
@@ -17,9 +17,9 @@ class DeveloperOptionsScreenViewModel: DeveloperOptionsScreenViewModelType, Deve
        actionsSubject.eraseToAnyPublisher()
    }
    
-    init(developerOptions: DeveloperOptionsProtocol, elementCallBaseURL: URL, isUsingNativeSlidingSync: Bool) {
+    init(developerOptions: DeveloperOptionsProtocol, elementCallBaseURL: URL) {
        let bindings = DeveloperOptionsScreenViewStateBindings(developerOptions: developerOptions)
-        let state = DeveloperOptionsScreenViewState(elementCallBaseURL: elementCallBaseURL, isUsingNativeSlidingSync: isUsingNativeSlidingSync, bindings: bindings)
+        let state = DeveloperOptionsScreenViewState(elementCallBaseURL: elementCallBaseURL, bindings: bindings)
        
        super.init(initialViewState: state)
    }
@@ -32,18 +32,6 @@ struct DeveloperOptionsScreen: View {
                }
            }
            
-            Section {
-                Picker("Discovery", selection: $context.slidingSyncDiscovery) {
-                    Text("Proxy only").tag(AppSettings.SlidingSyncDiscovery.proxy)
-                    Text("Automatic").tag(AppSettings.SlidingSyncDiscovery.native)
-                    Text("Force Native ⚠️").tag(AppSettings.SlidingSyncDiscovery.forceNative)
-                }
-            } header: {
-                Text("Sliding Sync")
-            } footer: {
-                Text(context.viewState.slidingSyncFooter)
-            }
-            
            Section("Room List") {
                Toggle(isOn: $context.publicSearchEnabled) {
                    Text("Public search")
@@ -175,8 +163,7 @@ private struct LogLevelConfigurationView: View {

 struct DeveloperOptionsScreen_Previews: PreviewProvider {
    static let viewModel = DeveloperOptionsScreenViewModel(developerOptions: ServiceLocator.shared.settings,
-                                                           elementCallBaseURL: ServiceLocator.shared.settings.elementCallBaseURL,
-                                                           isUsingNativeSlidingSync: true)
+                                                           elementCallBaseURL: ServiceLocator.shared.settings.elementCallBaseURL)
    static var previews: some View {
        NavigationStack {
            DeveloperOptionsScreen(context: viewModel.context)
@@ -27,55 +27,25 @@ struct AuthenticationClientBuilder: AuthenticationClientBuilderProtocol {
    
    /// Builds a Client for login using OIDC or password authentication.
    func build(homeserverAddress: String) async throws -> ClientProtocol {
-        if appSettings.slidingSyncDiscovery == .forceNative {
-            return try await makeClientBuilder(slidingSync: .forceNative).serverNameOrHomeserverUrl(serverNameOrUrl: homeserverAddress).build()
-        }
-        
-        if appSettings.slidingSyncDiscovery == .native {
-            do {
-                return try await makeClientBuilder(slidingSync: .discoverNative).serverNameOrHomeserverUrl(serverNameOrUrl: homeserverAddress).build()
-            } catch {
-                MXLog.warning("Native sliding sync not available: \(error)")
-                MXLog.info("Falling back to a sliding sync proxy.")
-            }
-        }
-        
-        return try await makeClientBuilder(slidingSync: .discoverProxy).serverNameOrHomeserverUrl(serverNameOrUrl: homeserverAddress).build()
+        try await makeClientBuilder().serverNameOrHomeserverUrl(serverNameOrUrl: homeserverAddress).build()
    }
    
    /// Builds a Client, authenticating with the given QR code data.
    func buildWithQRCode(qrCodeData: QrCodeData,
                         oidcConfiguration: OIDCConfigurationProxy,
                         progressListener: QrLoginProgressListenerProxy) async throws -> ClientProtocol {
-        if appSettings.slidingSyncDiscovery == .forceNative {
-            return try await makeClientBuilder(slidingSync: .forceNative).buildWithQrCode(qrCodeData: qrCodeData,
-                                                                                          oidcConfiguration: oidcConfiguration.rustValue,
-                                                                                          progressListener: progressListener)
-        }
-        
-        if appSettings.slidingSyncDiscovery == .native {
-            do {
-                return try await makeClientBuilder(slidingSync: .discoverNative).buildWithQrCode(qrCodeData: qrCodeData,
-                                                                                                 oidcConfiguration: oidcConfiguration.rustValue,
-                                                                                                 progressListener: progressListener)
-            } catch HumanQrLoginError.SlidingSyncNotAvailable {
-                MXLog.warning("Native sliding sync not available")
-                MXLog.info("Falling back to a sliding sync proxy.")
-            }
-        }
-        
-        return try await makeClientBuilder(slidingSync: .discoverProxy).buildWithQrCode(qrCodeData: qrCodeData,
-                                                                                        oidcConfiguration: oidcConfiguration.rustValue,
-                                                                                        progressListener: progressListener)
+        try await makeClientBuilder().buildWithQrCode(qrCodeData: qrCodeData,
+                                                      oidcConfiguration: oidcConfiguration.rustValue,
+                                                      progressListener: progressListener)
    }
    
    // MARK: - Private
    
    /// The base builder configuration used for authentication within the app.
-    private func makeClientBuilder(slidingSync: ClientBuilderSlidingSync) -> ClientBuilder {
+    private func makeClientBuilder() -> ClientBuilder {
        ClientBuilder
            .baseBuilder(httpProxy: appSettings.websiteURL.globalProxy,
-                         slidingSync: slidingSync,
+                         slidingSync: .discover,
                         sessionDelegate: clientSessionDelegate,
                         appHooks: appHooks,
                         enableOnlySignedDeviceIsolationMode: appSettings.enableOnlySignedDeviceIsolationMode,
@@ -19,7 +19,7 @@ class ClientProxy: ClientProxyProtocol {
    
    private let mediaLoader: MediaLoaderProtocol
    private let clientQueue: DispatchQueue
-        
+    
    private var roomListService: RoomListService?
    // periphery: ignore - only for retain
    private var roomListStateUpdateTaskHandle: TaskHandle?
@@ -135,6 +135,7 @@ class ClientProxy: ClientProxyProtocol {
    private let sendQueueStatusSubject = CurrentValueSubject<Bool, Never>(false)
    
    init(client: ClientProtocol,
+         needsSlidingSyncMigration: Bool,
         networkMonitor: NetworkMonitorProtocol,
         appSettings: AppSettings) async {
        self.client = client
@@ -148,6 +149,8 @@ class ClientProxy: ClientProxyProtocol {
        notificationSettings = NotificationSettingsProxy(notificationSettings: client.getNotificationSettings())
        
        secureBackupController = SecureBackupController(encryption: client.encryption())
+        
+        self.needsSlidingSyncMigration = needsSlidingSyncMigration

        delegateHandle = client.setDelegate(delegate: ClientDelegateWrapper { [weak self] isSoftLogout in
            self?.hasEncounteredAuthError = true
@@ -221,16 +224,11 @@ class ClientProxy: ClientProxyProtocol {
        client.homeserver()
    }
    
+    let needsSlidingSyncMigration: Bool
    var slidingSyncVersion: SlidingSyncVersion {
        client.slidingSyncVersion()
    }
    
-    var availableSlidingSyncVersions: [SlidingSyncVersion] {
-        get async {
-            await client.availableSlidingSyncVersions()
-        }
-    }
-    
    var canDeactivateAccount: Bool {
        client.canDeactivateAccount()
    }
@@ -263,6 +261,11 @@ class ClientProxy: ClientProxyProtocol {
    }

    func startSync() {
+        guard !needsSlidingSyncMigration else {
+            MXLog.warning("Ignoring request, this client needs to be migrated to native sliding sync.")
+            return
+        }
+        
        guard !hasEncounteredAuthError else {
            MXLog.warning("Ignoring request, this client has an unknown token.")
            return
@@ -75,9 +75,11 @@ protocol ClientProxyProtocol: AnyObject, MediaLoaderProtocol {
    var deviceID: String? { get }

    var homeserver: String { get }
-
+    
+    // TODO: This is a temporary value, in the future we should throw a migration error
+    // when decoding a session that contains a sliding sync proxy URL instead of restoring it.
+    var needsSlidingSyncMigration: Bool { get }
    var slidingSyncVersion: SlidingSyncVersion { get }
-    var availableSlidingSyncVersions: [SlidingSyncVersion] { get async }
    
    var canDeactivateAccount: Bool { get }
    
@@ -112,7 +112,8 @@ class KeychainController: KeychainControllerProtocol {
        let restorationToken = RestorationToken(session: session,
                                                sessionDirectories: oldToken.sessionDirectories,
                                                passphrase: oldToken.passphrase,
-                                                pusherNotificationClientIdentifier: oldToken.pusherNotificationClientIdentifier)
+                                                pusherNotificationClientIdentifier: oldToken.pusherNotificationClientIdentifier,
+                                                slidingSyncProxyURLString: oldToken.slidingSyncProxyURLString)
        setRestorationToken(restorationToken, forUsername: session.userId)
    }
    
@@ -14,6 +14,13 @@ struct RestorationToken: Equatable {
    let passphrase: String?
    let pusherNotificationClientIdentifier: String?
    
+    /// The sliding sync proxy URL that was previously encoded in the Session.
+    /// This is temporary to help make a nicer user migration flow. In the future
+    /// we will throw when decoding sessions with a sliding sync proxy URL.
+    let slidingSyncProxyURLString: String?
+    /// Whether the token is for a session that is using the now unsupported sliding sync proxy.
+    var needsSlidingSyncMigration: Bool { slidingSyncProxyURLString != nil }
+    
    enum CodingKeys: CodingKey {
        case session
        case sessionDirectory
@@ -27,7 +34,7 @@ extension RestorationToken: Codable {
    init(from decoder: Decoder) throws {
        let container = try decoder.container(keyedBy: CodingKeys.self)
        
-        let session = try container.decode(MatrixRustSDK.Session.self, forKey: .session)
+        let sessionWrapper = try container.decode(SessionWrapper.self, forKey: .session)
        let dataDirectory = try container.decodeIfPresent(URL.self, forKey: .sessionDirectory)
        let cacheDirectory = try container.decodeIfPresent(URL.self, forKey: .cacheDirectory)
        
@@ -38,18 +45,19 @@ extension RestorationToken: Codable {
                SessionDirectories(dataDirectory: dataDirectory)
            }
        } else {
-            SessionDirectories(userID: session.userId)
+            SessionDirectories(userID: sessionWrapper.session.userId)
        }
        
-        self = try .init(session: session,
+        self = try .init(session: sessionWrapper.session,
                         sessionDirectories: sessionDirectories,
                         passphrase: container.decodeIfPresent(String.self, forKey: .passphrase),
-                         pusherNotificationClientIdentifier: container.decodeIfPresent(String.self, forKey: .pusherNotificationClientIdentifier))
+                         pusherNotificationClientIdentifier: container.decodeIfPresent(String.self, forKey: .pusherNotificationClientIdentifier),
+                         slidingSyncProxyURLString: sessionWrapper.slidingSyncProxyURLString)
    }
    
    func encode(to encoder: any Encoder) throws {
        var container = encoder.container(keyedBy: CodingKeys.self)
-        try container.encode(session, forKey: .session)
+        try container.encode(SessionWrapper(session: session, slidingSyncProxyURLString: slidingSyncProxyURLString), forKey: .session)
        try container.encode(sessionDirectories.dataDirectory, forKey: .sessionDirectory)
        try container.encode(sessionDirectories.cacheDirectory, forKey: .cacheDirectory)
        try container.encode(passphrase, forKey: .passphrase)
@@ -57,17 +65,40 @@ extension RestorationToken: Codable {
    }
 }

+/// Temporary struct to smooth the forced migration by keeping a user session.
+/// In the future we can remove this and throw a migration error when the URL
+/// is decoded to a non-nil value.
+private struct SessionWrapper {
+    let session: MatrixRustSDK.Session
+    let slidingSyncProxyURLString: String?
+}
+
+extension SessionWrapper: Codable {
+    init(from decoder: Decoder) throws {
+        let container = try decoder.container(keyedBy: MatrixRustSDK.Session.CodingKeys.self)
+        session = try Session(from: decoder)
+        
+        // TODO: In the future we should decode this in the Session and throw a migration error if it contains a value.
+        slidingSyncProxyURLString = try container.decodeIfPresent(String.self, forKey: .slidingSyncProxy)
+    }
+    
+    func encode(to encoder: Encoder) throws {
+        var container = encoder.container(keyedBy: MatrixRustSDK.Session.CodingKeys.self)
+        try session.encode(to: encoder)
+        try container.encode(slidingSyncProxyURLString, forKey: .slidingSyncProxy)
+    }
+}
+
 extension MatrixRustSDK.Session: Codable {
    public init(from decoder: Decoder) throws {
        let container = try decoder.container(keyedBy: CodingKeys.self)
-        let slidingSyncProxy = try container.decodeIfPresent(String.self, forKey: .slidingSyncProxy)
        self = try .init(accessToken: container.decode(String.self, forKey: .accessToken),
                         refreshToken: container.decodeIfPresent(String.self, forKey: .refreshToken),
                         userId: container.decode(String.self, forKey: .userId),
                         deviceId: container.decode(String.self, forKey: .deviceId),
                         homeserverUrl: container.decode(String.self, forKey: .homeserverUrl),
                         oidcData: container.decodeIfPresent(String.self, forKey: .oidcData),
-                         slidingSyncVersion: slidingSyncProxy.map { .proxy(url: $0) } ?? .native)
+                         slidingSyncVersion: .native)
    }
    
    public func encode(to encoder: Encoder) throws {
@@ -78,17 +109,9 @@ extension MatrixRustSDK.Session: Codable {
        try container.encode(deviceId, forKey: .deviceId)
        try container.encode(homeserverUrl, forKey: .homeserverUrl)
        try container.encode(oidcData, forKey: .oidcData)
-        try container.encode(slidingSyncVersion.proxyURL, forKey: .slidingSyncProxy)
    }
    
    enum CodingKeys: String, CodingKey {
        case accessToken, refreshToken, userId, deviceId, homeserverUrl, oidcData, slidingSyncProxy
    }
 }
-
-private extension SlidingSyncVersion {
-    var proxyURL: String? {
-        guard case let .proxy(url) = self else { return nil }
-        return url
-    }
-}
@@ -64,12 +64,13 @@ class UserSessionStore: UserSessionStoreProtocol {
        do {
            let session = try client.session()
            let userID = try client.userId()
-            let clientProxy = await setupProxyForClient(client)
+            let clientProxy = await setupProxyForClient(client, needsSlidingSyncMigration: false)
            
            keychainController.setRestorationToken(RestorationToken(session: session,
                                                                    sessionDirectories: sessionDirectories,
                                                                    passphrase: passphrase,
-                                                                    pusherNotificationClientIdentifier: clientProxy.pusherNotificationClientIdentifier),
+                                                                    pusherNotificationClientIdentifier: clientProxy.pusherNotificationClientIdentifier,
+                                                                    slidingSyncProxyURLString: nil),
                                                   forUsername: userID)
            
            MXLog.info("Set up session for user \(userID) at: \(sessionDirectories)")
@@ -145,15 +146,16 @@ class UserSessionStore: UserSessionStoreProtocol {
            
            MXLog.info("Set up session for user \(credentials.userID) at: \(credentials.restorationToken.sessionDirectories)")
            
-            return await .success(setupProxyForClient(client))
+            return await .success(setupProxyForClient(client, needsSlidingSyncMigration: credentials.restorationToken.needsSlidingSyncMigration))
        } catch {
            MXLog.error("Failed restoring login with error: \(error)")
            return .failure(.failedRestoringLogin)
        }
    }
    
-    private func setupProxyForClient(_ client: ClientProtocol) async -> ClientProxyProtocol {
+    private func setupProxyForClient(_ client: ClientProtocol, needsSlidingSyncMigration: Bool) async -> ClientProxyProtocol {
        await ClientProxy(client: client,
+                          needsSlidingSyncMigration: needsSlidingSyncMigration,
                          networkMonitor: networkMonitor,
                          appSettings: appSettings)
    }