fix(outlinekit): correct preferences wire keys to the real server shape

All preference toggles showed as off regardless of server state, and
saving notificationBadge 400'd with "notificationBadge: Invalid Input" —
the guessed wire keys/values from the earlier speculative commit were
wrong. Fixed against a live network capture of Outline's own web app
toggling every one of these settings:

- separateEditing -> seamlessEdit, and inverted (seamlessEdit is
  separate editing's negation, confirmed by toggling it live)
- showCommentMarker -> commentsInGutter
- smartText -> enableSmartText
- notificationBadge values -> "disabled"/"indicator"/"count", not the
  guessed "none"/"unread"/"all"
- rememberLastPath/useCursorPointer/codeBlockLineNumbers were already
  correct

Also preserves fullWidthDocuments (a real preference this app has no UI
for) on round-trip, since the client always sends the whole preferences
object back on save — dropping an unrecognized key during decode would
otherwise silently clear it the next time any toggle here gets saved.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

OutlineKit/Sources/OutlineKit/Caching/CachingOutlineAPIClient.swift

@@ -355,6 +355,18 @@ public actor CachingOutlineAPIClient: OutlineAPIClient {
         try await live.updateUserName(request)
     }
 
+    public func updateUserLanguage(_ request: UpdateUserLanguageRequest) async throws -> OutlineUser {
+        try await live.updateUserLanguage(request)
+    }
+
+    public func updateUserPreferences(_ request: UpdateUserPreferencesRequest) async throws -> OutlineUser {
+        try await live.updateUserPreferences(request)
+    }
+
+    public func deleteAccount() async throws {
+        try await live.deleteAccount()
+    }
+
     // MARK: - Sync management (Settings surface)
 
     public func pendingOperations() async -> [PendingOperationSummary] {

OutlineKit/Sources/OutlineKit/Core/OutlineAPIClient.swift

@@ -83,4 +83,12 @@ public protocol OutlineAPIClient: Sendable {
     func updateUserAvatar(_ request: UpdateUserAvatarRequest) async throws -> OutlineUser
     /// `users.update`, name only. See `UpdateUserNameRequest`.
     func updateUserName(_ request: UpdateUserNameRequest) async throws -> OutlineUser
+    /// `users.update`, language only. See `UpdateUserLanguageRequest`.
+    func updateUserLanguage(_ request: UpdateUserLanguageRequest) async throws -> OutlineUser
+    /// `users.update`, preferences only. See `UpdateUserPreferencesRequest`.
+    func updateUserPreferences(_ request: UpdateUserPreferencesRequest) async throws -> OutlineUser
+    /// Backed by `users.delete` — self-service account deletion, no
+    /// confirmation code param confirmed live, matches every other simple
+    /// no-body delete in this API.
+    func deleteAccount() async throws
 }

OutlineKit/Sources/OutlineKit/LiveOutlineAPIClient.swift

@@ -290,6 +290,18 @@ public actor LiveOutlineAPIClient: OutlineAPIClient {
         try await post("users.update", body: request)
     }
 
+    public func updateUserLanguage(_ request: UpdateUserLanguageRequest) async throws -> OutlineUser {
+        try await post("users.update", body: request)
+    }
+
+    public func updateUserPreferences(_ request: UpdateUserPreferencesRequest) async throws -> OutlineUser {
+        try await post("users.update", body: request)
+    }
+
+    public func deleteAccount() async throws {
+        try await postForSuccess("users.delete", body: EmptyParams())
+    }
+
     private func post<Body: Encodable, Response: Decodable>(_ path: String, body: Body) async throws -> Response {
         guard let token = try? tokenStore.token() else {
             throw OutlineAPIError.tokenUnavailable

OutlineKit/Sources/OutlineKit/Models/OutlineUser.swift

@@ -6,18 +6,24 @@ public struct OutlineUser: Codable, Identifiable, Hashable, Sendable {
     public let email: String?
     public let avatarUrl: String?
     public let role: String?
+    public let language: String?
+    public let preferences: OutlineUserPreferences?
 
     public init(
         id: String,
         name: String,
         email: String? = nil,
         avatarUrl: String? = nil,
-        role: String? = nil
+        role: String? = nil,
+        language: String? = nil,
+        preferences: OutlineUserPreferences? = nil
     ) {
         self.id = id
         self.name = name
         self.email = email
         self.avatarUrl = avatarUrl
         self.role = role
+        self.language = language
+        self.preferences = preferences
     }
 }

OutlineKit/Sources/OutlineKit/Models/OutlineUserPreferences.swift

@@ -0,0 +1,109 @@
+import Foundation
+
+/// `User.preferences` — a free-form JSON blob on Outline's own `User` row,
+/// not a fixed-shape API resource. Wire key names below are confirmed
+/// against a live server's own web app traffic (captured toggling every
+/// Preferences setting one at a time), not guessed — see the `CodingKeys`
+/// mapping for the two that don't match this struct's own property names.
+///
+/// The server also validates `preferences` against a known key allowlist
+/// and rejects the whole `users.update` call (not just the bad field) if
+/// any key it doesn't recognize is present — confirmed live via a
+/// `"notificationBadge: Invalid Input"` error when an earlier, wrong value
+/// was sent. That's also why `fullWidthDocuments` is kept here even though
+/// this app has no UI for it yet: this app always sends the *whole*
+/// preferences object back on every save (see
+/// `UpdateUserPreferencesRequest`), so silently dropping an unknown key
+/// during decode would permanently clear it the next time any other
+/// preference here gets saved.
+public struct OutlineUserPreferences: Codable, Hashable, Sendable {
+    public var rememberLastPath: Bool?
+    /// App-facing polarity: `true` means "separate editing mode is on" —
+    /// the opposite of the wire's own `seamlessEdit` (seamless editing and
+    /// separate editing modes are each other's negation), inverted in
+    /// `init(from:)`/`encode(to:)` so nothing outside this file has to
+    /// remember that.
+    public var separateEditing: Bool?
+    public var useCursorPointer: Bool?
+    public var codeBlockLineNumbers: Bool?
+    public var showCommentMarker: Bool?
+    public var smartText: Bool?
+    /// One of `NotificationBadgeStyle`'s raw values.
+    public var notificationBadge: String?
+    /// No UI in this app yet — preserved purely so saving any other
+    /// preference here doesn't clobber it. See the type doc comment.
+    public var fullWidthDocuments: Bool?
+
+    public init(
+        rememberLastPath: Bool? = nil,
+        separateEditing: Bool? = nil,
+        useCursorPointer: Bool? = nil,
+        codeBlockLineNumbers: Bool? = nil,
+        showCommentMarker: Bool? = nil,
+        smartText: Bool? = nil,
+        notificationBadge: String? = nil,
+        fullWidthDocuments: Bool? = nil
+    ) {
+        self.rememberLastPath = rememberLastPath
+        self.separateEditing = separateEditing
+        self.useCursorPointer = useCursorPointer
+        self.codeBlockLineNumbers = codeBlockLineNumbers
+        self.showCommentMarker = showCommentMarker
+        self.smartText = smartText
+        self.notificationBadge = notificationBadge
+        self.fullWidthDocuments = fullWidthDocuments
+    }
+
+    private enum CodingKeys: String, CodingKey {
+        case rememberLastPath
+        case seamlessEdit
+        case useCursorPointer
+        case codeBlockLineNumbers
+        case commentsInGutter
+        case enableSmartText
+        case notificationBadge
+        case fullWidthDocuments
+    }
+
+    public init(from decoder: Decoder) throws {
+        let container = try decoder.container(keyedBy: CodingKeys.self)
+        rememberLastPath = try container.decodeIfPresent(Bool.self, forKey: .rememberLastPath)
+        separateEditing = try container.decodeIfPresent(Bool.self, forKey: .seamlessEdit).map { !$0 }
+        useCursorPointer = try container.decodeIfPresent(Bool.self, forKey: .useCursorPointer)
+        codeBlockLineNumbers = try container.decodeIfPresent(Bool.self, forKey: .codeBlockLineNumbers)
+        showCommentMarker = try container.decodeIfPresent(Bool.self, forKey: .commentsInGutter)
+        smartText = try container.decodeIfPresent(Bool.self, forKey: .enableSmartText)
+        notificationBadge = try container.decodeIfPresent(String.self, forKey: .notificationBadge)
+        fullWidthDocuments = try container.decodeIfPresent(Bool.self, forKey: .fullWidthDocuments)
+    }
+
+    public func encode(to encoder: Encoder) throws {
+        var container = encoder.container(keyedBy: CodingKeys.self)
+        try container.encodeIfPresent(rememberLastPath, forKey: .rememberLastPath)
+        try container.encodeIfPresent(separateEditing.map { !$0 }, forKey: .seamlessEdit)
+        try container.encodeIfPresent(useCursorPointer, forKey: .useCursorPointer)
+        try container.encodeIfPresent(codeBlockLineNumbers, forKey: .codeBlockLineNumbers)
+        try container.encodeIfPresent(showCommentMarker, forKey: .commentsInGutter)
+        try container.encodeIfPresent(smartText, forKey: .enableSmartText)
+        try container.encodeIfPresent(notificationBadge, forKey: .notificationBadge)
+        try container.encodeIfPresent(fullWidthDocuments, forKey: .fullWidthDocuments)
+    }
+}
+
+/// App-icon unread indicator style. Wire values confirmed live (captured
+/// setting all three from Outline's own web app).
+public enum NotificationBadgeStyle: String, CaseIterable, Identifiable, Sendable {
+    case none = "disabled"
+    case unreadIndicator = "indicator"
+    case unreadCount = "count"
+
+    public var id: String { rawValue }
+
+    public var label: String {
+        switch self {
+        case .none: return "None"
+        case .unreadIndicator: return "Unread Indicator"
+        case .unreadCount: return "Unread Count"
+        }
+    }
+}

OutlineKit/Sources/OutlineKit/Requests/UpdateUserLanguageRequest.swift

@@ -0,0 +1,12 @@
+import Foundation
+
+/// `users.update`, language only.
+public struct UpdateUserLanguageRequest: Encodable, Sendable {
+    public let id: String
+    public let language: String
+
+    public init(id: String, language: String) {
+        self.id = id
+        self.language = language
+    }
+}

OutlineKit/Sources/OutlineKit/Requests/UpdateUserPreferencesRequest.swift

@@ -0,0 +1,14 @@
+import Foundation
+
+/// `users.update`, preferences only. Sends the *whole* preferences object
+/// back (not a single changed key) — avoids needing to know whether the
+/// server deep-merges a partial `preferences` body or replaces it outright.
+public struct UpdateUserPreferencesRequest: Encodable, Sendable {
+    public let id: String
+    public let preferences: OutlineUserPreferences
+
+    public init(id: String, preferences: OutlineUserPreferences) {
+        self.id = id
+        self.preferences = preferences
+    }
+}

OutlineKit/Tests/OutlineKitTests/CachingOutlineAPIClientTests.swift

@@ -94,6 +94,9 @@ private final class StubOutlineAPIClient: OutlineAPIClient, @unchecked Sendable
     func deleteAttachment(id: String) async throws { throw NotStubbed() }
     func updateUserAvatar(_ request: UpdateUserAvatarRequest) async throws -> OutlineUser { throw NotStubbed() }
     func updateUserName(_ request: UpdateUserNameRequest) async throws -> OutlineUser { throw NotStubbed() }
+    func updateUserLanguage(_ request: UpdateUserLanguageRequest) async throws -> OutlineUser { throw NotStubbed() }
+    func updateUserPreferences(_ request: UpdateUserPreferencesRequest) async throws -> OutlineUser { throw NotStubbed() }
+    func deleteAccount() async throws { throw NotStubbed() }
 }
 
 private struct StubTransportError: Error {}

OutlineKit/Tests/OutlineKitTests/LiveOutlineAPIClientTests.swift

@@ -1074,6 +1074,127 @@ final class LiveOutlineAPIClientTests: XCTestCase {
         XCTAssertEqual(httpClient.lastRequest?.url?.path, "/api/users.update")
     }
 
+    func testUpdateUserLanguageSendsRequestAndDecodesResult() async throws {
+        let httpClient = MockHTTPClient()
+        httpClient.responseData = """
+        {
+            "data": {
+                "id": "user-1",
+                "name": "Jane Doe",
+                "language": "fr_FR"
+            }
+        }
+        """.data(using: .utf8)!
+
+        let client = LiveOutlineAPIClient(
+            configuration: OutlineConfiguration(baseURL: URL(string: "https://outline.example.com")!),
+            tokenStore: StaticTokenStore(),
+            httpClient: httpClient
+        )
+
+        let user = try await client.updateUserLanguage(UpdateUserLanguageRequest(id: "user-1", language: "fr_FR"))
+
+        XCTAssertEqual(user.language, "fr_FR")
+        XCTAssertEqual(httpClient.lastRequest?.url?.path, "/api/users.update")
+    }
+
+    func testUpdateUserPreferencesSendsWholeObjectAndDecodesResult() async throws {
+        let httpClient = MockHTTPClient()
+        httpClient.responseData = """
+        {
+            "data": {
+                "id": "user-1",
+                "name": "Jane Doe",
+                "preferences": { "rememberLastPath": true, "useCursorPointer": true }
+            }
+        }
+        """.data(using: .utf8)!
+
+        let client = LiveOutlineAPIClient(
+            configuration: OutlineConfiguration(baseURL: URL(string: "https://outline.example.com")!),
+            tokenStore: StaticTokenStore(),
+            httpClient: httpClient
+        )
+
+        let preferences = OutlineUserPreferences(rememberLastPath: true, useCursorPointer: true)
+        let user = try await client.updateUserPreferences(UpdateUserPreferencesRequest(id: "user-1", preferences: preferences))
+
+        XCTAssertEqual(user.preferences?.rememberLastPath, true)
+        XCTAssertEqual(user.preferences?.useCursorPointer, true)
+
+        let sentBody = try JSONSerialization.jsonObject(with: httpClient.lastRequest!.httpBody!) as? [String: Any]
+        let sentPreferences = sentBody?["preferences"] as? [String: Any]
+        XCTAssertEqual(sentPreferences?["rememberLastPath"] as? Bool, true)
+        XCTAssertEqual(sentPreferences?["useCursorPointer"] as? Bool, true)
+    }
+
+    /// Locks in the wire mapping confirmed against a live server's own web
+    /// app traffic: `seamlessEdit`/`commentsInGutter`/`enableSmartText` are
+    /// the real keys (not `separateEditing`/`showCommentMarker`/`smartText`
+    /// this struct exposes), and `seamlessEdit` is the *negation* of this
+    /// app's `separateEditing`.
+    func testOutlineUserPreferencesDecodesRealWireKeys() throws {
+        let json = """
+        {
+            "seamlessEdit": false,
+            "commentsInGutter": true,
+            "enableSmartText": true,
+            "rememberLastPath": true,
+            "useCursorPointer": true,
+            "codeBlockLineNumbers": false,
+            "notificationBadge": "indicator",
+            "fullWidthDocuments": true
+        }
+        """.data(using: .utf8)!
+
+        let preferences = try JSONDecoder().decode(OutlineUserPreferences.self, from: json)
+
+        XCTAssertEqual(preferences.separateEditing, true, "seamlessEdit: false means separate editing is ON")
+        XCTAssertEqual(preferences.showCommentMarker, true)
+        XCTAssertEqual(preferences.smartText, true)
+        XCTAssertEqual(preferences.rememberLastPath, true)
+        XCTAssertEqual(preferences.useCursorPointer, true)
+        XCTAssertEqual(preferences.codeBlockLineNumbers, false)
+        XCTAssertEqual(preferences.notificationBadge, "indicator")
+        XCTAssertEqual(preferences.fullWidthDocuments, true)
+    }
+
+    func testOutlineUserPreferencesEncodesRealWireKeysAndInvertsSeparateEditing() throws {
+        var preferences = OutlineUserPreferences()
+        preferences.separateEditing = true
+        preferences.showCommentMarker = false
+        preferences.smartText = true
+        preferences.fullWidthDocuments = true
+
+        let data = try JSONEncoder().encode(preferences)
+        let object = try JSONSerialization.jsonObject(with: data) as? [String: Any]
+
+        XCTAssertEqual(object?["seamlessEdit"] as? Bool, false, "separateEditing: true must encode as seamlessEdit: false")
+        XCTAssertEqual(object?["commentsInGutter"] as? Bool, false)
+        XCTAssertEqual(object?["enableSmartText"] as? Bool, true)
+        XCTAssertEqual(object?["fullWidthDocuments"] as? Bool, true)
+        XCTAssertNil(object?["separateEditing"], "must not leak this app's own field name onto the wire")
+        XCTAssertNil(object?["showCommentMarker"])
+        XCTAssertNil(object?["smartText"])
+    }
+
+    func testDeleteAccountSendsRequest() async throws {
+        let httpClient = MockHTTPClient()
+        httpClient.responseData = """
+        { "success": true }
+        """.data(using: .utf8)!
+
+        let client = LiveOutlineAPIClient(
+            configuration: OutlineConfiguration(baseURL: URL(string: "https://outline.example.com")!),
+            tokenStore: StaticTokenStore(),
+            httpClient: httpClient
+        )
+
+        try await client.deleteAccount()
+
+        XCTAssertEqual(httpClient.lastRequest?.url?.path, "/api/users.delete")
+    }
+
     func testDeleteAttachmentSendsRequest() async throws {
         let httpClient = MockHTTPClient()
         httpClient.responseData = """

Outpost/Features/Account/SettingsView.swift

@@ -32,6 +32,13 @@ struct SettingsView: View {
     @State private var editableName = ""
     @State private var isSavingName = false
     @State private var nameErrorMessage: String?
+    @State private var isSavingLanguage = false
+    @State private var languageErrorMessage: String?
+    @State private var isSavingPreferences = false
+    @State private var preferencesErrorMessage: String?
+    @State private var isShowingDeleteAccountConfirmation = false
+    @State private var isDeletingAccount = false
+    @State private var deleteAccountErrorMessage: String?
 
     /// Full Local Sync and cache-clearing both need a real connection to be
     /// safe — clearing while offline (or letting Full Local Sync think it
@@ -71,6 +78,7 @@ struct SettingsView: View {
         switch section {
         case .appearance: appearanceDetail
         case .profile: profileDetail
+        case .preferences: preferencesDetail
         case .offlineSync: offlineSyncDetail
         case .advanced: advancedDetail
         case .about: aboutDetail
@@ -231,6 +239,296 @@ struct SettingsView: View {
         .frame(maxWidth: 420, alignment: .leading)
     }
 
+    // MARK: - Preferences
+
+    private var preferencesDetail: some View {
+        VStack(alignment: .leading, spacing: 24) {
+            sectionHeader
+            Text("Manage settings that affect your personal experience.")
+                .font(.subheadline)
+                .foregroundStyle(.secondary)
+
+            preferencesSubsection("Display") {
+                languageRow
+                Divider()
+                appearanceRow
+                Divider()
+                preferenceToggleRow(
+                    "Use pointer cursor",
+                    description: "Show a hand cursor when hovering over interactive elements.",
+                    isOn: session.userPreferences?.useCursorPointer ?? false,
+                    onChange: { newValue in Task { await savePreference { $0.useCursorPointer = newValue } } }
+                )
+                Divider()
+                preferenceToggleRow(
+                    "Show line numbers",
+                    description: "Show line numbers on code blocks in documents.",
+                    isOn: session.userPreferences?.codeBlockLineNumbers ?? false,
+                    onChange: { newValue in Task { await savePreference { $0.codeBlockLineNumbers = newValue } } }
+                )
+                Divider()
+                preferenceToggleRow(
+                    "Show comment marker",
+                    description: "Display a marker beside lines in the editor that contain comments.",
+                    isOn: session.userPreferences?.showCommentMarker ?? false,
+                    onChange: { newValue in Task { await savePreference { $0.showCommentMarker = newValue } } }
+                )
+            }
+
+            preferencesSubsection("Behavior") {
+                preferenceToggleRow(
+                    "Separate editing",
+                    description: "When enabled, documents have a separate editing mode. When disabled, documents are always editable when you have permission.",
+                    isOn: session.userPreferences?.separateEditing ?? false,
+                    onChange: { newValue in Task { await savePreference { $0.separateEditing = newValue } } }
+                )
+                Divider()
+                preferenceToggleRow(
+                    "Remember previous location",
+                    description: "Automatically return to the document you were last viewing when the app is re-opened.",
+                    isOn: session.userPreferences?.rememberLastPath ?? false,
+                    onChange: { newValue in Task { await savePreference { $0.rememberLastPath = newValue } } }
+                )
+                Divider()
+                preferenceToggleRow(
+                    "Smart text replacements",
+                    description: "Auto-format text by replacing shortcuts with symbols, dashes, smart quotes, and other typographical elements.",
+                    isOn: session.userPreferences?.smartText ?? false,
+                    onChange: { newValue in Task { await savePreference { $0.smartText = newValue } } }
+                )
+                Divider()
+                notificationBadgeRow
+            }
+
+            if let preferencesErrorMessage {
+                Text(preferencesErrorMessage)
+                    .font(.caption)
+                    .foregroundStyle(.red)
+            }
+
+            preferencesSubsection("Danger") {
+                deleteAccountRow
+            }
+        }
+        .frame(maxWidth: 480, alignment: .leading)
+        .task { await refreshProfile() }
+        .confirmationDialog(
+            "Delete Account?",
+            isPresented: $isShowingDeleteAccountConfirmation,
+            titleVisibility: .visible
+        ) {
+            Button("Delete Account", role: .destructive) { Task { await deleteAccount() } }
+            Button("Cancel", role: .cancel) {}
+        } message: {
+            Text("This is unrecoverable — everything associated with your account will be permanently deleted.")
+        }
+    }
+
+    private var deleteAccountRow: some View {
+        VStack(alignment: .leading, spacing: 6) {
+            HStack {
+                VStack(alignment: .leading, spacing: 2) {
+                    Text("Delete account")
+                    Text("You may delete your account at any time, note that this is unrecoverable.")
+                        .font(.caption)
+                        .foregroundStyle(.secondary)
+                }
+                Spacer()
+                if isDeletingAccount {
+                    ProgressView().controlSize(.small)
+                } else {
+                    Button("Delete…", role: .destructive) { isShowingDeleteAccountConfirmation = true }
+                        .buttonStyle(.bordered)
+                        .tint(.red)
+                }
+            }
+            if let deleteAccountErrorMessage {
+                Text(deleteAccountErrorMessage)
+                    .font(.caption)
+                    .foregroundStyle(.red)
+            }
+        }
+    }
+
+    private func preferencesSubsection<Content: View>(
+        _ title: String,
+        @ViewBuilder content: () -> Content
+    ) -> some View {
+        VStack(alignment: .leading, spacing: 14) {
+            Text(title)
+                .font(.headline)
+            content()
+        }
+    }
+
+    private var languageRow: some View {
+        VStack(alignment: .leading, spacing: 6) {
+            HStack {
+                VStack(alignment: .leading, spacing: 2) {
+                    Text("Language")
+                    Text("Choose the interface language. Community translations are accepted through our translation portal.")
+                        .font(.caption)
+                        .foregroundStyle(.secondary)
+                }
+                Spacer()
+                if isSavingLanguage {
+                    ProgressView().controlSize(.small)
+                } else {
+                    Picker("Language", selection: languageBinding) {
+                        ForEach(displayedLocales) { locale in
+                            Text(locale.label).tag(locale.code)
+                        }
+                    }
+                    .labelsHidden()
+                    .frame(width: 200)
+                }
+            }
+            if let languageErrorMessage {
+                Text(languageErrorMessage)
+                    .font(.caption)
+                    .foregroundStyle(.red)
+            }
+        }
+    }
+
+    /// Same `@AppStorage("outpost.appearance")` binding the standalone
+    /// Appearance section already uses — this is a local-only, device-side
+    /// preference (matches how this app has always handled it), not a
+    /// server-synced Outline preference, so it doesn't need its own
+    /// save call or error state.
+    private var appearanceRow: some View {
+        HStack {
+            VStack(alignment: .leading, spacing: 2) {
+                Text("Appearance")
+                Text("Choose your preferred interface colour scheme.")
+                    .font(.caption)
+                    .foregroundStyle(.secondary)
+            }
+            Spacer()
+            Picker("Appearance", selection: $appearance) {
+                ForEach(AppAppearance.allCases) { option in
+                    Text(option.label).tag(option)
+                }
+            }
+            .labelsHidden()
+            .frame(width: 200)
+        }
+    }
+
+    private var notificationBadgeRow: some View {
+        HStack {
+            VStack(alignment: .leading, spacing: 2) {
+                Text("Notification badge")
+                Text("Choose how unread notifications are indicated on the app icon.")
+                    .font(.caption)
+                    .foregroundStyle(.secondary)
+            }
+            Spacer()
+            Picker("Notification badge", selection: notificationBadgeBinding) {
+                ForEach(NotificationBadgeStyle.allCases) { style in
+                    Text(style.label).tag(style)
+                }
+            }
+            .labelsHidden()
+            .frame(width: 160)
+        }
+    }
+
+    private var notificationBadgeBinding: Binding<NotificationBadgeStyle> {
+        Binding(
+            get: {
+                session.userPreferences?.notificationBadge.flatMap(NotificationBadgeStyle.init(rawValue:)) ?? .unreadCount
+            },
+            set: { newValue in Task { await savePreference { $0.notificationBadge = newValue.rawValue } } }
+        )
+    }
+
+    /// `OutlineLocale.all` is a curated subset, not Outline's full list —
+    /// a self-hosted server can report a code we don't know about (seen
+    /// live: "en_GB"). `Picker` needs a `Text` for every possible selection
+    /// or it logs "invalid tag" and its displayed value goes undefined —
+    /// appending the current code here (using itself as the label, same
+    /// fallback `OutlineLocale.label(for:)` already uses) guarantees a
+    /// match no matter what the server sends.
+    private var displayedLocales: [OutlineLocale] {
+        guard let current = session.userLanguage, !OutlineLocale.all.contains(where: { $0.code == current }) else {
+            return OutlineLocale.all
+        }
+        return OutlineLocale.all + [OutlineLocale(code: current, label: OutlineLocale.label(for: current))]
+    }
+
+    private var languageBinding: Binding<String> {
+        Binding(
+            get: { session.userLanguage ?? "en_US" },
+            set: { newValue in Task { await saveLanguage(newValue) } }
+        )
+    }
+
+    private func deleteAccount() async {
+        guard let apiClient = session.apiClient else { return }
+        isDeletingAccount = true
+        defer { isDeletingAccount = false }
+        do {
+            try await apiClient.deleteAccount()
+            session.signOut()
+        } catch {
+            deleteAccountErrorMessage = outlineErrorMessage(error, fallback: "Couldn't delete your account.")
+        }
+    }
+
+    private func saveLanguage(_ code: String) async {
+        guard code != session.userLanguage, let apiClient = session.apiClient, let userId = session.userId else { return }
+        isSavingLanguage = true
+        defer { isSavingLanguage = false }
+        do {
+            let updated = try await apiClient.updateUserLanguage(UpdateUserLanguageRequest(id: userId, language: code))
+            session.applyUpdatedProfile(updated)
+            languageErrorMessage = nil
+        } catch {
+            languageErrorMessage = outlineErrorMessage(error, fallback: "Couldn't update your language.")
+        }
+    }
+
+    /// Every toggle in the Preferences page shares this: read
+    /// `session.userPreferences` (or an empty object if nothing's been set
+    /// yet), flip the one field the caller cares about, send the *whole*
+    /// object back — see `UpdateUserPreferencesRequest`'s own doc comment
+    /// for why the full object rather than a partial diff.
+    private func savePreference(_ update: (inout OutlineUserPreferences) -> Void) async {
+        guard let apiClient = session.apiClient, let userId = session.userId else { return }
+        var preferences = session.userPreferences ?? OutlineUserPreferences()
+        update(&preferences)
+        isSavingPreferences = true
+        defer { isSavingPreferences = false }
+        do {
+            let updated = try await apiClient.updateUserPreferences(
+                UpdateUserPreferencesRequest(id: userId, preferences: preferences)
+            )
+            session.applyUpdatedProfile(updated)
+            preferencesErrorMessage = nil
+        } catch {
+            preferencesErrorMessage = outlineErrorMessage(error, fallback: "Couldn't update your preferences.")
+        }
+    }
+
+    private func preferenceToggleRow(
+        _ title: String,
+        description: String,
+        isOn: Bool,
+        onChange: @escaping (Bool) -> Void
+    ) -> some View {
+        VStack(alignment: .leading, spacing: 2) {
+            Toggle(isOn: Binding(get: { isOn }, set: onChange)) {
+                VStack(alignment: .leading, spacing: 2) {
+                    Text(title)
+                    Text(description)
+                        .font(.caption)
+                        .foregroundStyle(.secondary)
+                }
+            }
+        }
+    }
+
     // MARK: - Offline & Sync
 
     private var offlineSyncDetail: some View {

Outpost/Root/AppNavigation.swift

@@ -122,7 +122,7 @@ enum SettingsSection: String, CaseIterable, Identifiable, Hashable {
     /// placeholder until its content is specified and built.
     var isImplemented: Bool {
         switch self {
-        case .appearance, .offlineSync, .advanced, .about, .profile:
+        case .appearance, .offlineSync, .advanced, .about, .profile, .preferences:
             return true
         default:
             return false

Outpost/Root/SessionStore.swift

@@ -15,6 +15,8 @@ final class SessionStore {
     var userName: String?
     var userEmail: String?
     var userAvatarURL: URL?
+    var userLanguage: String?
+    var userPreferences: OutlineUserPreferences?
     var teamName: String?
     var teamAvatarURL: URL?
     private(set) var apiClient: OutlineAPIClient?
@@ -73,6 +75,8 @@ final class SessionStore {
         userName = nil
         userEmail = nil
         userAvatarURL = nil
+        userLanguage = nil
+        userPreferences = nil
         teamName = nil
         teamAvatarURL = nil
         apiClient = nil
@@ -95,6 +99,8 @@ final class SessionStore {
         userId = user.id
         userName = user.name
         userAvatarURL = user.avatarUrl.flatMap { URL(string: $0, relativeTo: serverURL)?.absoluteURL }
+        userLanguage = user.language
+        userPreferences = user.preferences
     }
 
     private func apply(user: OutlineUser, team: OutlineTeam, serverURL: URL) {
@@ -105,6 +111,8 @@ final class SessionStore {
         // (e.g. `/api/files.get?key=...`) for avatarUrl — resolve against the
         // configured server so relative paths don't fail as "unsupported URL".
         userAvatarURL = user.avatarUrl.flatMap { URL(string: $0, relativeTo: serverURL)?.absoluteURL }
+        userLanguage = user.language
+        userPreferences = user.preferences
         teamName = team.name
         teamAvatarURL = team.avatarUrl.flatMap { URL(string: $0, relativeTo: serverURL)?.absoluteURL }
     }

Outpost/Support/OutlineLocale.swift

@@ -0,0 +1,35 @@
+import Foundation
+
+/// Outline's interface-language options. Not exhaustive — Outline accepts
+/// community translations via its own translation portal, so the real list
+/// on any given server can be longer than this; this covers the common
+/// cases and falls back to showing whatever code the server already has
+/// set even if it isn't in this list.
+struct OutlineLocale: Identifiable, Hashable {
+    let code: String
+    let label: String
+
+    var id: String { code }
+
+    static let all: [OutlineLocale] = [
+        OutlineLocale(code: "en_US", label: "English (US)"),
+        OutlineLocale(code: "en_GB", label: "English (UK)"),
+        OutlineLocale(code: "de_DE", label: "Deutsch"),
+        OutlineLocale(code: "fr_FR", label: "Français"),
+        OutlineLocale(code: "es_ES", label: "Español"),
+        OutlineLocale(code: "pt_PT", label: "Português"),
+        OutlineLocale(code: "pt_BR", label: "Português (Brasil)"),
+        OutlineLocale(code: "it_IT", label: "Italiano"),
+        OutlineLocale(code: "nl_NL", label: "Nederlands"),
+        OutlineLocale(code: "pl_PL", label: "Polski"),
+        OutlineLocale(code: "ru_RU", label: "Русский"),
+        OutlineLocale(code: "ja_JP", label: "日本語"),
+        OutlineLocale(code: "ko_KR", label: "한국어"),
+        OutlineLocale(code: "zh_CN", label: "中文 (简体)"),
+        OutlineLocale(code: "zh_TW", label: "中文 (繁體)"),
+    ]
+
+    static func label(for code: String) -> String {
+        all.first(where: { $0.code == code })?.label ?? code
+    }
+}