From ced652911ba577b937c3d48d9db3ae942f776d29 Mon Sep 17 00:00:00 2001
From: maple <maple@MacBook-Air.local>
Date: Tue, 2 Jun 2026 20:52:49 +0800
Subject: [PATCH 1/6] docs: add localization design

---
 .../specs/2026-06-02-localization-design.md   | 285 ++++++++++++++++++
 1 file changed, 285 insertions(+)
 create mode 100644 docs/superpowers/specs/2026-06-02-localization-design.md

diff --git a/docs/superpowers/specs/2026-06-02-localization-design.md b/docs/superpowers/specs/2026-06-02-localization-design.md
new file mode 100644
index 0000000..a25dcd2
--- /dev/null
+++ b/docs/superpowers/specs/2026-06-02-localization-design.md
@@ -0,0 +1,285 @@
+# Localization Design
+
+## Purpose
+
+Sub2API Status Bar should support users who prefer English or Simplified Chinese without making the macOS menu bar app feel heavier. The first localization slice will add an in-app language setting with Auto, English, and 简体中文 choices, then localize both visible UI and generated text that users copy or receive as local notifications.
+
+The project already has a partial foundation:
+
+- `AppLanguage` exists with `auto`, `zhHans`, and `en` cases.
+- `AppConfig.language` is already persisted and can be seeded from `SUB2API_LANGUAGE`.
+- The Settings language picker was intentionally removed earlier because localization was not wired.
+- Most UI and generated report text is still hard-coded in English.
+
+This design turns the existing language field into a working preference instead of adding a parallel system.
+
+## Scope
+
+### In Scope
+
+- Add a working Settings language picker: Auto, English, 简体中文.
+- Resolve `AppLanguage.auto` from the current system locale at render/generation time.
+- Localize app-owned text in:
+  - login and connection views,
+  - monitor panel,
+  - dashboard cards,
+  - charts and quota views,
+  - Settings sections,
+  - update checking UI,
+  - button labels, help strings, accessibility labels, and menu bar tooltip text.
+- Localize generated app text in:
+  - usage insights,
+  - local insight notifications,
+  - recovery suggestions,
+  - onboarding checklist,
+  - usage report copy,
+  - diagnostics copy,
+  - support bundle copy,
+  - social share summary and share card labels.
+- Keep user and server data unchanged: emails, account names, URLs, model names, release names, server error messages, currency amounts, and raw metrics are not translated.
+- Add focused tests for language resolution, config persistence, English compatibility, Simplified Chinese output, and token redaction in localized generated text.
+- Update README, README.zh-CN, and CHANGELOG for the new language setting.
+
+### Out of Scope
+
+- Adding more languages beyond English and Simplified Chinese.
+- Shipping external translator workflows, `.xliff` export, or App Store localization metadata.
+- Translating backend-provided text or GitHub release content.
+- Replacing all existing tests with locale snapshots.
+- Changing the app's data model, network endpoints, update mechanism, or credential storage behavior.
+
+## Recommended Approach
+
+Use a code-owned localization layer in `Sub2APIStatusCore`, not Apple `.strings` or `.xcstrings` resources for this first PR.
+
+Reasons:
+
+- The app is a SwiftPM executable with a reusable core library, and many user-facing strings are generated in core types.
+- The requested language can change at runtime from Settings; code-based lookup makes immediate refresh straightforward.
+- Tests can assert localized output directly without an Xcode project or bundle-resource edge cases.
+- The repo already started with `AppLanguage`, so the smallest coherent change is to complete that path.
+
+Apple resource localization remains a valid future migration if the project grows to many languages or needs translator tooling.
+
+## Architecture
+
+### Language Resolution
+
+Add a small resolver in core, for example:
+
+- `AppLanguage.resolved(preferredLanguages:) -> AppLanguage`
+- `AppLanguage.currentResolved() -> AppLanguage`
+
+Rules:
+
+- `.en` resolves to `.en`.
+- `.zhHans` resolves to `.zhHans`.
+- `.auto` resolves to `.zhHans` when the preferred language starts with `zh`, `zh-Hans`, `zh-CN`, or another Simplified Chinese compatible identifier.
+- `.auto` resolves to `.en` for everything else.
+
+The resolver should be deterministic and directly testable by passing language identifiers instead of depending only on the live machine locale.
+
+### Localization API
+
+Create a small code localization layer in `Sub2APIStatusCore`, for example:
+
+- `AppStrings`
+- `LocalizedStringKey` is not used as the storage type because core-generated reports need plain `String`.
+- `AppStrings(language: AppLanguage, preferredLanguages: [String] = Locale.preferredLanguages)` resolves the effective language once and exposes methods/properties that return `String`.
+
+The API should support two patterns:
+
+1. Static labels:
+   - settings title,
+   - button labels,
+   - section headings,
+   - update status labels.
+2. Dynamic sentences:
+   - stale data label,
+   - quota remaining text,
+   - token surge insight detail,
+   - generated report lines.
+
+Avoid a giant untyped dictionary for dynamic strings. Prefer grouped computed properties and functions so call sites remain discoverable and compiler-checked.
+
+### UI Integration
+
+`MonitorViewModel` already publishes `config` and `settingsDraft`, so SwiftUI can refresh when `config.language` changes.
+
+Expected UI flow:
+
+1. User opens Settings.
+2. User changes `Language` picker in General.
+3. User clicks Save.
+4. `saveSettings()` persists `settingsDraft.language`.
+5. `config.language` updates.
+6. `MonitorPanel`, Settings, menu bar title/tooltip, and generated copy actions use the new language on next render/action.
+
+For views, use a lightweight helper from the model or local computed value:
+
+- `let strings = AppStrings(language: model.config.language)` for committed settings.
+- `let strings = AppStrings(language: model.settingsDraft.language)` inside editable Settings controls when the picker itself should update immediately while editing.
+
+The language picker belongs in `GeneralSettingsSection`, near other app-wide preferences. Its choices should be:
+
+- `Auto`
+- `English`
+- `简体中文`
+
+The display names may remain self-identifying so users can recover if they choose an unfamiliar language.
+
+### Core Generated Text Integration
+
+Core report and summary generators should accept a language or strings object rather than reaching into global UI state.
+
+Target shape:
+
+- `UsageReport.make(snapshot:config:now:language:)`
+- `DiagnosticReport.make(snapshot:config:now:language:)`
+- `SupportBundleReport.make(snapshot:config:now:language:)`
+- `SocialShareSummary.make(snapshot:config:now:language:)`
+- usage insight builders receive language through config or explicit parameters where they already receive thresholds/settings.
+
+The exact signatures can vary to keep diffs small, but the dependency direction should stay clear:
+
+- `Sub2APIStatusCore` does not import SwiftUI or AppKit.
+- `Sub2APIStatusBar` passes `model.config.language` into core generators.
+- Tests can call core generators with `.en` and `.zhHans` directly.
+
+### Notifications
+
+Local notifications should use the configured app language at the time the notification is created. If the user changes language later, already-delivered macOS notification text does not need to change.
+
+`InsightNotifier` should receive either `AppLanguage` or `AppStrings` through the existing notification path. Keep notification identifiers stable and language-independent.
+
+### Diagnostics And Support Bundle
+
+Diagnostics and support bundle text should be user-readable in the selected language, but token redaction and support safety are higher priority than translation.
+
+Rules:
+
+- Continue redacting access tokens, refresh tokens, passwords, and secret-looking values.
+- Keep raw URLs, account email, app version, refresh interval, and menu bar metric values intact.
+- It is acceptable to keep a few stable technical field names in English if changing them would make support parsing brittle.
+- Tests must cover redaction for both English and Simplified Chinese output.
+
+### Social Share Card
+
+The share summary and image card should use localized labels and punchline text. Numeric values, model names, and dates stay formatted consistently with the existing app unless a focused formatter change is required.
+
+The card renderer should receive localized strings from `SocialShareSummary` rather than reimplementing language decisions inside drawing code.
+
+## File Plan
+
+Likely files to create:
+
+- `Sources/Sub2APIStatusCore/AppStrings.swift`
+
+Likely files to modify:
+
+- `Sources/Sub2APIStatusCore/AppConfig.swift`
+- `Sources/Sub2APIStatusCore/Models.swift`
+- `Sources/Sub2APIStatusCore/UsageInsights.swift`
+- `Sources/Sub2APIStatusCore/InsightAlertPolicy.swift`
+- `Sources/Sub2APIStatusCore/OnboardingChecklist.swift`
+- `Sources/Sub2APIStatusCore/RecoverySuggestion.swift`
+- `Sources/Sub2APIStatusCore/UsageReport.swift`
+- `Sources/Sub2APIStatusCore/DiagnosticReport.swift`
+- `Sources/Sub2APIStatusCore/SupportBundleReport.swift`
+- `Sources/Sub2APIStatusCore/SocialShareSummary.swift`
+- `Sources/Sub2APIStatusBar/Sub2APIStatusBarApp.swift`
+- `Sources/Sub2APIStatusBar/MonitorViewModel.swift`
+- `Sources/Sub2APIStatusBar/LoginViews.swift`
+- `Sources/Sub2APIStatusBar/MonitorPanel.swift`
+- `Sources/Sub2APIStatusBar/DashboardComponents.swift`
+- `Sources/Sub2APIStatusBar/ChartViews.swift`
+- `Sources/Sub2APIStatusBar/QuotaViews.swift`
+- `Sources/Sub2APIStatusBar/SettingsView.swift`
+- `Sources/Sub2APIStatusBar/SharedViews.swift`
+- `Sources/Sub2APIStatusBar/SocialShareCard.swift`
+- `Tests/Sub2APIStatusCoreTests/Sub2APIStatusCoreTests.swift`
+- `README.md`
+- `README.zh-CN.md`
+- `CHANGELOG.md`
+
+The implementation plan may split these into smaller tasks to keep each commit reviewable.
+
+## Testing Strategy
+
+Run narrow tests first, then full checks:
+
+1. Add unit tests for `AppLanguage` resolution:
+   - `.en` stays English.
+   - `.zhHans` stays Simplified Chinese.
+   - `.auto` with `zh-Hans` resolves Simplified Chinese.
+   - `.auto` with `en-US` resolves English.
+2. Add unit tests for config persistence:
+   - saved `language` round-trips.
+   - old config without `language` decodes as `.auto`.
+   - `SUB2API_LANGUAGE=zh-Hans` seeds defaults.
+3. Add core output tests:
+   - English report retains existing important labels.
+   - Simplified Chinese report contains Chinese labels.
+   - diagnostics/support bundle redacts secrets in both languages.
+   - insight/recovery/checklist output changes with language.
+4. Add UI-level compile verification through `swift build`.
+5. Run:
+   - `swift test`
+   - `swift build`
+
+Manual verification for the final implementation:
+
+- Launch app with default Auto on an English system and confirm English UI.
+- Set language to 简体中文, save, reopen panel, confirm visible UI changes.
+- Copy Usage Report, Diagnostics, Support Bundle, and Share Card; confirm selected-language labels and redaction.
+- Switch back to English and confirm UI/report labels return to English.
+
+## Documentation Updates
+
+`README.md` should mention the Language setting under Settings. `README.zh-CN.md` should describe Auto / English / 简体中文 in Chinese. `CHANGELOG.md` should add an unreleased or next-version entry consistent with the existing format.
+
+The PR body should call out:
+
+- language setting added,
+- UI and generated text localized,
+- no telemetry added,
+- diagnostics remain token-redacted,
+- checks run.
+
+## Risks And Mitigations
+
+### Risk: PR becomes too large
+
+Mitigation: keep the architecture simple, avoid Apple resource migration, and split implementation commits by localization infrastructure, UI/generated text wiring, and docs/tests.
+
+### Risk: English behavior regresses
+
+Mitigation: preserve existing English strings where practical and add focused tests for existing report/menu/status labels.
+
+### Risk: Generated support text becomes harder to parse
+
+Mitigation: translate human-facing wording but preserve raw values and any field names that are likely to be used for support triage.
+
+### Risk: Some text remains hard-coded
+
+Mitigation: run `rg` over Swift string-heavy UI patterns before final verification and explicitly document any intentionally untranslated strings.
+
+### Risk: Runtime language switching misses menu bar tooltip/title
+
+Mitigation: after saving settings, call the existing status item update path or trigger snapshot-change handling so menu bar text uses the new language immediately.
+
+## Acceptance Criteria
+
+- Settings exposes a working Language picker with Auto, English, and 简体中文.
+- Selecting English produces English UI and generated app text.
+- Selecting 简体中文 produces Simplified Chinese UI and generated app text.
+- Auto follows system preferred language for English vs Simplified Chinese.
+- Usage Report, Diagnostics, Support Bundle, Social Share text/card, insights, notifications, recovery suggestions, and onboarding checklist use the selected language.
+- Server-provided/user data remains unmodified.
+- Diagnostics and support bundle remain token-redacted.
+- README, README.zh-CN, and CHANGELOG document the feature.
+- `swift test` and `swift build` pass.
+
+## Approval Gate
+
+This spec is ready for implementation planning after review. Implementation should start with a detailed plan saved under `docs/superpowers/plans/` and should use small, verifiable commits.

From ad7f38a2d902de41d046259b8cfe4d98afde80c7 Mon Sep 17 00:00:00 2001
From: maple <maple@MacBook-Air.local>
Date: Tue, 2 Jun 2026 20:55:53 +0800
Subject: [PATCH 2/6] docs: add localization implementation plan

---
 .../plans/2026-06-02-localization.md          | 216 ++++++++++++++++++
 1 file changed, 216 insertions(+)
 create mode 100644 docs/superpowers/plans/2026-06-02-localization.md

diff --git a/docs/superpowers/plans/2026-06-02-localization.md b/docs/superpowers/plans/2026-06-02-localization.md
new file mode 100644
index 0000000..2c87e7e
--- /dev/null
+++ b/docs/superpowers/plans/2026-06-02-localization.md
@@ -0,0 +1,216 @@
+# Localization Implementation Plan
+
+> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking.
+
+**Goal:** Add a working Auto / English / Simplified Chinese language setting that localizes app UI and generated user-facing text.
+
+**Architecture:** Complete the existing `AppLanguage` path with a code-owned `AppStrings` localization layer in `Sub2APIStatusCore`. Pass the configured language from `MonitorViewModel` into SwiftUI views, status item updates, notifications, and generated report/share helpers. Keep server/user data unchanged and preserve support-safe token redaction.
+
+**Tech Stack:** Swift 6.1, SwiftPM executable/library targets, SwiftUI/AppKit, Swift Testing.
+
+---
+
+## File Structure
+
+- Create `Sources/Sub2APIStatusCore/AppStrings.swift`: language resolution and grouped localized strings/functions used by both core and app targets.
+- Modify `Sources/Sub2APIStatusCore/AppConfig.swift`: add resolver/display helpers for language setting.
+- Modify core generators in `Sources/Sub2APIStatusCore/*.swift`: accept `AppLanguage` or `AppStrings` where user-facing text is generated.
+- Modify app views in `Sources/Sub2APIStatusBar/*.swift`: replace hard-coded UI labels with `AppStrings` where practical and add the Settings picker.
+- Modify `Tests/Sub2APIStatusCoreTests/Sub2APIStatusCoreTests.swift`: add focused localization tests and update existing English expectations if signatures change.
+- Modify `README.md`, `README.zh-CN.md`, and `CHANGELOG.md`: document the language setting.
+
+## Task 1: Language Resolution And String Layer
+
+**Files:**
+- Create: `Sources/Sub2APIStatusCore/AppStrings.swift`
+- Modify: `Sources/Sub2APIStatusCore/AppConfig.swift`
+- Test: `Tests/Sub2APIStatusCoreTests/Sub2APIStatusCoreTests.swift`
+
+- [ ] **Step 1: Write failing tests**
+
+Add tests that assert language resolution and basic labels:
+
+```swift
+@Test func appLanguageResolvesAutoFromPreferredLanguages() {
+    #expect(AppLanguage.auto.resolved(preferredLanguages: ["zh-Hans-US"]) == .zhHans)
+    #expect(AppLanguage.auto.resolved(preferredLanguages: ["zh-CN"]) == .zhHans)
+    #expect(AppLanguage.auto.resolved(preferredLanguages: ["en-US"]) == .en)
+    #expect(AppLanguage.en.resolved(preferredLanguages: ["zh-Hans"]) == .en)
+    #expect(AppLanguage.zhHans.resolved(preferredLanguages: ["en-US"]) == .zhHans)
+}
+
+@Test func appStringsReturnLocalizedStaticLabels() {
+    #expect(AppStrings(language: .en).settings == "Settings")
+    #expect(AppStrings(language: .zhHans).settings == "设置")
+    #expect(AppStrings(language: .en).languageDisplayName(.auto) == "Auto")
+    #expect(AppStrings(language: .zhHans).languageDisplayName(.auto) == "自动")
+}
+```
+
+- [ ] **Step 2: Run red test**
+
+Run: `swift test --filter appLanguageResolvesAutoFromPreferredLanguages`
+Expected: FAIL because `resolved(preferredLanguages:)` and/or `AppStrings` do not exist yet.
+
+- [ ] **Step 3: Implement language resolution and initial strings**
+
+Add `AppStrings` with enough labels to pass the tests plus common UI labels used in later tasks. Add `AppLanguage.resolved(preferredLanguages:)` and `resolved()` helpers in `AppConfig.swift`.
+
+- [ ] **Step 4: Run green tests**
+
+Run: `swift test --filter appLanguageResolvesAutoFromPreferredLanguages && swift test --filter appStringsReturnLocalizedStaticLabels`
+Expected: PASS.
+
+- [ ] **Step 5: Commit**
+
+```bash
+git add Sources/Sub2APIStatusCore/AppStrings.swift Sources/Sub2APIStatusCore/AppConfig.swift Tests/Sub2APIStatusCoreTests/Sub2APIStatusCoreTests.swift
+git commit -m "feat: add localization string layer"
+```
+
+## Task 2: Localize Core Generated Text
+
+**Files:**
+- Modify: `Sources/Sub2APIStatusCore/Models.swift`
+- Modify: `Sources/Sub2APIStatusCore/UsageInsights.swift`
+- Modify: `Sources/Sub2APIStatusCore/OnboardingChecklist.swift`
+- Modify: `Sources/Sub2APIStatusCore/RecoverySuggestion.swift`
+- Modify: `Sources/Sub2APIStatusCore/UsageReport.swift`
+- Modify: `Sources/Sub2APIStatusCore/DiagnosticReport.swift`
+- Modify: `Sources/Sub2APIStatusCore/SupportBundleReport.swift`
+- Modify: `Sources/Sub2APIStatusCore/SocialShareSummary.swift`
+- Test: `Tests/Sub2APIStatusCoreTests/Sub2APIStatusCoreTests.swift`
+
+- [ ] **Step 1: Write failing tests**
+
+Add tests for Chinese generated text and redaction:
+
+```swift
+@Test func usageReportCanRenderSimplifiedChinese() {
+    let config = AppConfig(baseURL: "https://sub2api.example.com", language: .zhHans)
+    let report = UsageReport.make(snapshot: .sampleConnected, config: config, now: Date(timeIntervalSince1970: 1_700_000_000), language: .zhHans)
+    #expect(report.contains("状态"))
+    #expect(report.contains("账户"))
+}
+
+@Test func diagnosticsRemainRedactedWhenLocalized() {
+    let config = AppConfig(baseURL: "https://sub2api.example.com", authToken: "secret-token", refreshToken: "refresh-secret", language: .zhHans)
+    let report = DiagnosticReport.make(snapshot: .sampleConnected, config: config, now: Date(timeIntervalSince1970: 1_700_000_000), language: .zhHans)
+    #expect(report.contains("[REDACTED]"))
+    #expect(!report.contains("secret-token"))
+    #expect(!report.contains("refresh-secret"))
+}
+```
+
+If `.sampleConnected` is not available, use the existing test fixture factory already present in the test file.
+
+- [ ] **Step 2: Run red tests**
+
+Run: `swift test --filter usageReportCanRenderSimplifiedChinese`
+Expected: FAIL because localized signatures/output do not exist yet.
+
+- [ ] **Step 3: Implement minimal core localization**
+
+Thread language through core report/share/checklist/recovery/insight functions. Preserve existing English output where practical. Keep backward-compatible overloads when many existing call sites/tests use old signatures.
+
+- [ ] **Step 4: Run core tests**
+
+Run: `swift test`
+Expected: PASS or only failures from app-target compile changes not yet updated. Fix core test regressions before continuing.
+
+- [ ] **Step 5: Commit**
+
+```bash
+git add Sources/Sub2APIStatusCore Tests/Sub2APIStatusCoreTests/Sub2APIStatusCoreTests.swift
+git commit -m "feat: localize generated app text"
+```
+
+## Task 3: Localize App UI And Runtime Language Setting
+
+**Files:**
+- Modify: `Sources/Sub2APIStatusBar/Sub2APIStatusBarApp.swift`
+- Modify: `Sources/Sub2APIStatusBar/MonitorViewModel.swift`
+- Modify: `Sources/Sub2APIStatusBar/LoginViews.swift`
+- Modify: `Sources/Sub2APIStatusBar/MonitorPanel.swift`
+- Modify: `Sources/Sub2APIStatusBar/DashboardComponents.swift`
+- Modify: `Sources/Sub2APIStatusBar/ChartViews.swift`
+- Modify: `Sources/Sub2APIStatusBar/QuotaViews.swift`
+- Modify: `Sources/Sub2APIStatusBar/SettingsView.swift`
+- Modify: `Sources/Sub2APIStatusBar/SharedViews.swift`
+- Modify: `Sources/Sub2APIStatusBar/SocialShareCard.swift`
+
+- [ ] **Step 1: Add Settings language picker**
+
+In `GeneralSettingsSection`, add a `Language` row with `Picker` bound to `$model.settingsDraft.language` and choices from `AppLanguage.allCases` using localized display labels.
+
+- [ ] **Step 2: Pass language into generated copy actions and notifications**
+
+Update `MonitorViewModel` copy/report/share/notification calls to pass `config.language`.
+
+- [ ] **Step 3: Localize high-impact UI labels**
+
+Replace visible hard-coded labels in Settings, Login, MonitorPanel, dashboard/charts/quota, help strings, and app status tooltip with `AppStrings` values/functions. Do not translate user data or server data.
+
+- [ ] **Step 4: Build app target**
+
+Run: `swift build`
+Expected: PASS.
+
+- [ ] **Step 5: Commit**
+
+```bash
+git add Sources/Sub2APIStatusBar Sources/Sub2APIStatusCore
+git commit -m "feat: add runtime language setting"
+```
+
+## Task 4: Documentation And Final Verification
+
+**Files:**
+- Modify: `README.md`
+- Modify: `README.zh-CN.md`
+- Modify: `CHANGELOG.md`
+
+- [ ] **Step 1: Document language setting**
+
+Update both READMEs Settings sections to mention Auto / English / 简体中文. Add a CHANGELOG entry for app localization.
+
+- [ ] **Step 2: Search for missed obvious hard-coded UI strings**
+
+Run:
+
+```bash
+rg -n 'Text\("|Label\("|Button\("|Toggle\("|\.help\("|accessibilityDescription: "|toolTip = "' Sources/Sub2APIStatusBar Sources/Sub2APIStatusCore
+```
+
+Review results. Convert missed app-owned text or document intentional exceptions in the final summary.
+
+- [ ] **Step 3: Full verification**
+
+Run:
+
+```bash
+swift test
+swift build
+```
+
+Expected: both PASS.
+
+- [ ] **Step 4: Re-read changed files**
+
+Run:
+
+```bash
+git diff --stat upstream/main...HEAD
+git diff --check
+git status --short --branch
+```
+
+Expected: no whitespace errors; only intended files changed.
+
+- [ ] **Step 5: Commit docs/final fixes**
+
+```bash
+git add README.md README.zh-CN.md CHANGELOG.md
+# Include any final localization fixes found in Step 2.
+git commit -m "docs: document language setting"
+```

From fdf54c57d736f6c72e41604683879a8ef7161a56 Mon Sep 17 00:00:00 2001
From: maple <maple@MacBook-Air.local>
Date: Tue, 2 Jun 2026 20:57:04 +0800
Subject: [PATCH 3/6] feat: add localization string layer

---
 Sources/Sub2APIStatusCore/AppConfig.swift     |  16 +-
 Sources/Sub2APIStatusCore/AppStrings.swift    | 140 ++++++++++++++++++
 .../Sub2APIStatusCoreTests.swift              |  15 ++
 3 files changed, 166 insertions(+), 5 deletions(-)
 create mode 100644 Sources/Sub2APIStatusCore/AppStrings.swift

diff --git a/Sources/Sub2APIStatusCore/AppConfig.swift b/Sources/Sub2APIStatusCore/AppConfig.swift
index b09b5c2..3acfed6 100644
--- a/Sources/Sub2APIStatusCore/AppConfig.swift
+++ b/Sources/Sub2APIStatusCore/AppConfig.swift
@@ -8,13 +8,19 @@ public enum AppLanguage: String, Codable, CaseIterable, Identifiable, Sendable {
     public var id: String { rawValue }
 
     public var displayName: String {
+        AppStrings(language: .en).languageDisplayName(self)
+    }
+
+    public func resolved(preferredLanguages: [String] = Locale.preferredLanguages) -> AppLanguage {
         switch self {
+        case .en, .zhHans:
+            return self
         case .auto:
-            "Auto"
-        case .zhHans:
-            "简体中文"
-        case .en:
-            "English"
+            let preferred = preferredLanguages.first?.trimmingCharacters(in: .whitespacesAndNewlines).lowercased() ?? ""
+            if preferred == "zh" || preferred.hasPrefix("zh-") {
+                return .zhHans
+            }
+            return .en
         }
     }
 
diff --git a/Sources/Sub2APIStatusCore/AppStrings.swift b/Sources/Sub2APIStatusCore/AppStrings.swift
new file mode 100644
index 0000000..d801103
--- /dev/null
+++ b/Sources/Sub2APIStatusCore/AppStrings.swift
@@ -0,0 +1,140 @@
+import Foundation
+
+public struct AppStrings: Sendable {
+    public let language: AppLanguage
+
+    public init(language: AppLanguage, preferredLanguages: [String] = Locale.preferredLanguages) {
+        self.language = language.resolved(preferredLanguages: preferredLanguages)
+    }
+
+    public var settings: String { text(en: "Settings", zhHans: "设置") }
+    public var cancel: String { text(en: "Cancel", zhHans: "取消") }
+    public var save: String { text(en: "Save", zhHans: "保存") }
+    public var refresh: String { text(en: "Refresh", zhHans: "刷新") }
+    public var quit: String { text(en: "Quit", zhHans: "退出") }
+    public var open: String { text(en: "Open", zhHans: "打开") }
+    public var post: String { text(en: "Post", zhHans: "发布") }
+    public var report: String { text(en: "Report", zhHans: "报告") }
+    public var details: String { text(en: "Details", zhHans: "详情") }
+    public var disconnected: String { text(en: "Disconnected", zhHans: "未连接") }
+    public var general: String { text(en: "General", zhHans: "通用") }
+    public var accounts: String { text(en: "Accounts", zhHans: "账户") }
+    public var alerts: String { text(en: "Alerts", zhHans: "提醒") }
+    public var insights: String { text(en: "Insights", zhHans: "洞察") }
+    public var diagnostics: String { text(en: "Diagnostics", zhHans: "诊断") }
+    public var updates: String { text(en: "Updates", zhHans: "更新") }
+    public var login: String { text(en: "Login", zhHans: "登录") }
+    public var languageSetting: String { text(en: "Language", zhHans: "语言") }
+    public var baseURL: String { text(en: "Base URL", zhHans: "基础 URL") }
+    public var menuBar: String { text(en: "Menu Bar", zhHans: "菜单栏") }
+    public var showText: String { text(en: "Show text", zhHans: "显示文字") }
+    public var metric: String { text(en: "Metric", zhHans: "指标") }
+    public var startup: String { text(en: "Startup", zhHans: "启动") }
+    public var launchAtLogin: String { text(en: "Launch at login", zhHans: "登录时启动") }
+    public var token: String { text(en: "Token", zhHans: "令牌") }
+    public var bearerToken: String { text(en: "Bearer Token", zhHans: "Bearer 令牌") }
+    public var notify: String { text(en: "Notify", zhHans: "通知") }
+    public var usageInsights: String { text(en: "Usage Insights", zhHans: "用量洞察") }
+    public var warning: String { text(en: "Warning", zhHans: "警告") }
+    public var errorOnly: String { text(en: "Error only", zhHans: "仅错误") }
+    public var cooldown: String { text(en: "Cooldown", zhHans: "冷却时间") }
+    public var today: String { text(en: "Today", zhHans: "今日") }
+    public var balance: String { text(en: "balance", zhHans: "余额") }
+    public var tokens: String { text(en: "tokens", zhHans: "令牌数") }
+    public var waitingForUsageData: String { text(en: "Waiting for usage data.", zhHans: "正在等待用量数据。") }
+    public var setBaseURLAndToken: String { text(en: "Set Base URL and token to start monitoring.", zhHans: "设置基础 URL 和令牌以开始监控。") }
+    public var shareCard: String { text(en: "Share Card", zhHans: "分享卡片") }
+    public var copyShareCard: String { text(en: "Copy Share Card", zhHans: "复制分享卡片") }
+    public var copyUsageReport: String { text(en: "Copy Usage Report", zhHans: "复制用量报告") }
+    public var copyDiagnostics: String { text(en: "Copy Diagnostics", zhHans: "复制诊断") }
+    public var copySupportBundle: String { text(en: "Copy Support Bundle", zhHans: "复制支持包") }
+    public var showConfig: String { text(en: "Show Config", zhHans: "显示配置") }
+    public var openServer: String { text(en: "Open Server", zhHans: "打开服务器") }
+    public var manualToken: String { text(en: "Manual token", zhHans: "手动令牌") }
+    public var saveToken: String { text(en: "Save Token", zhHans: "保存令牌") }
+    public var connectionChecklist: String { text(en: "Connection Checklist", zhHans: "连接检查清单") }
+    public var connectYourServer: String { text(en: "Connect your server", zhHans: "连接你的服务器") }
+    public var serverURL: String { text(en: "Server URL", zhHans: "服务器 URL") }
+    public var connecting: String { text(en: "Connecting...", zhHans: "正在连接…") }
+    public var loginAndSaveAccount: String { text(en: "Login and Save Account", zhHans: "登录并保存账户") }
+    public var removeCurrentAccount: String { text(en: "Remove Current Account", zhHans: "移除当前账户") }
+    public var checkNow: String { text(en: "Check Now", zhHans: "立即检查") }
+    public var openRelease: String { text(en: "Open Release", zhHans: "打开发布页") }
+    public var downloadLatestRelease: String { text(en: "Download the latest release from GitHub.", zhHans: "从 GitHub 下载最新版本。") }
+    public var githubReleaseCheck: String { text(en: "Checks GitHub Releases for newer versions.", zhHans: "检查 GitHub Releases 是否有新版本。") }
+    public var averageResponse: String { text(en: "Average Response", zhHans: "平均响应") }
+    public var averageTime: String { text(en: "Average time", zhHans: "平均耗时") }
+    public var status: String { text(en: "Status", zhHans: "状态") }
+    public var account: String { text(en: "Account", zhHans: "账户") }
+    public var generated: String { text(en: "Generated", zhHans: "生成时间") }
+    public var notConnected: String { text(en: "Not connected", zhHans: "未连接") }
+    public var staleData: String { text(en: "Stale Data", zhHans: "数据已过期") }
+    public var noData: String { text(en: "No Data", zhHans: "无数据") }
+    public var healthy: String { text(en: "Healthy", zhHans: "正常") }
+    public var needsAttention: String { text(en: "Needs Attention", zhHans: "需要关注") }
+    public var error: String { text(en: "Error", zhHans: "错误") }
+
+    public func languageDisplayName(_ value: AppLanguage) -> String {
+        switch value {
+        case .auto:
+            text(en: "Auto", zhHans: "自动")
+        case .en:
+            "English"
+        case .zhHans:
+            "简体中文"
+        }
+    }
+
+    public func menuBarMetricDisplayName(_ metric: MenuBarMetric) -> String {
+        switch metric {
+        case .automatic:
+            text(en: "Auto", zhHans: "自动")
+        case .spend:
+            text(en: "Spend", zhHans: "花费")
+        case .balance:
+            text(en: "Balance", zhHans: "余额")
+        case .quota:
+            text(en: "Quota", zhHans: "配额")
+        case .tokens:
+            text(en: "Tokens", zhHans: "令牌")
+        case .requests:
+            text(en: "Requests", zhHans: "请求")
+        }
+    }
+
+    public func statusLabel(_ severity: MonitorSeverity) -> String {
+        switch severity {
+        case .healthy:
+            healthy
+        case .warning:
+            needsAttention
+        case .error:
+            error
+        }
+    }
+
+    public func daysLeft(_ days: Int) -> String {
+        text(en: "\(days)d left", zhHans: "剩余 \(days) 天")
+    }
+
+    public func quotaAccessibility(title: String, percent: String, remaining: String) -> String {
+        text(en: "\(title) quota \(percent), \(remaining)", zhHans: "\(title) 配额 \(percent)，\(remaining)")
+    }
+
+    public func sub2APIStatus(_ statusLabel: String) -> String {
+        "Sub2API \(statusLabel)"
+    }
+
+    public func statusTooltip(statusLabel: String, todayCost: String, rpm: String) -> String {
+        text(en: "Sub2API \(statusLabel) - Today \(todayCost), RPM \(rpm)", zhHans: "Sub2API \(statusLabel) - 今日 \(todayCost)，RPM \(rpm)")
+    }
+
+    public func text(en: String, zhHans: String) -> String {
+        switch language {
+        case .zhHans:
+            zhHans
+        case .auto, .en:
+            en
+        }
+    }
+}
diff --git a/Tests/Sub2APIStatusCoreTests/Sub2APIStatusCoreTests.swift b/Tests/Sub2APIStatusCoreTests/Sub2APIStatusCoreTests.swift
index 6100314..49e9709 100644
--- a/Tests/Sub2APIStatusCoreTests/Sub2APIStatusCoreTests.swift
+++ b/Tests/Sub2APIStatusCoreTests/Sub2APIStatusCoreTests.swift
@@ -30,6 +30,21 @@ import Testing
     #expect(config.showsMenuBarText == false)
 }
 
+@Test func appLanguageResolvesAutoFromPreferredLanguages() {
+    #expect(AppLanguage.auto.resolved(preferredLanguages: ["zh-Hans-US"]) == .zhHans)
+    #expect(AppLanguage.auto.resolved(preferredLanguages: ["zh-CN"]) == .zhHans)
+    #expect(AppLanguage.auto.resolved(preferredLanguages: ["en-US"]) == .en)
+    #expect(AppLanguage.en.resolved(preferredLanguages: ["zh-Hans"]) == .en)
+    #expect(AppLanguage.zhHans.resolved(preferredLanguages: ["en-US"]) == .zhHans)
+}
+
+@Test func appStringsReturnLocalizedStaticLabels() {
+    #expect(AppStrings(language: .en).settings == "Settings")
+    #expect(AppStrings(language: .zhHans).settings == "设置")
+    #expect(AppStrings(language: .en).languageDisplayName(.auto) == "Auto")
+    #expect(AppStrings(language: .zhHans).languageDisplayName(.auto) == "自动")
+}
+
 private func pngSize(_ data: Data) -> (width: Int, height: Int)? {
     guard data.count >= 24 else {
         return nil

From 9a718fb63ddfc5f1a9cea7c92111d09559ad3464 Mon Sep 17 00:00:00 2001
From: maple <maple@MacBook-Air.local>
Date: Tue, 2 Jun 2026 21:04:44 +0800
Subject: [PATCH 4/6] feat: localize generated app text

---
 .../Sub2APIStatusBar/InsightNotifier.swift    |  6 +-
 Sources/Sub2APIStatusBar/LoginViews.swift     |  3 +-
 Sources/Sub2APIStatusBar/MonitorPanel.swift   |  3 +-
 .../Sub2APIStatusBar/MonitorViewModel.swift   | 27 ++++--
 .../Sub2APIStatusCore/DiagnosticReport.swift  | 77 +++++++++-------
 .../InsightAlertPolicy.swift                  | 31 ++++---
 Sources/Sub2APIStatusCore/Models.swift        | 57 +++++++-----
 .../OnboardingChecklist.swift                 | 34 +++----
 .../RecoverySuggestion.swift                  | 43 ++++-----
 .../SocialShareSummary.swift                  | 89 ++++++++++---------
 .../SupportBundleReport.swift                 | 55 ++++++------
 Sources/Sub2APIStatusCore/UsageInsights.swift | 78 ++++++++--------
 Sources/Sub2APIStatusCore/UsageReport.swift   | 80 +++++++++--------
 .../Sub2APIStatusCoreTests.swift              | 71 +++++++++++++++
 14 files changed, 393 insertions(+), 261 deletions(-)

diff --git a/Sources/Sub2APIStatusBar/InsightNotifier.swift b/Sources/Sub2APIStatusBar/InsightNotifier.swift
index 4359280..e19776c 100644
--- a/Sources/Sub2APIStatusBar/InsightNotifier.swift
+++ b/Sources/Sub2APIStatusBar/InsightNotifier.swift
@@ -27,14 +27,16 @@ final class InsightNotifier {
         _ snapshot: MonitorSnapshot,
         refreshIntervalSeconds: Double,
         settings: InsightAlertSettings,
-        now: Date = Date()
+        now: Date = Date(),
+        language: AppLanguage = .en
     ) {
         let policy = InsightAlertPolicy(settings: settings)
         guard let alert = policy.staleDataAlert(
             from: snapshot,
             refreshIntervalSeconds: refreshIntervalSeconds,
             lastAlertedAtByFingerprint: lastAlertedAtByFingerprint,
-            now: now
+            now: now,
+            language: language
         ) else {
             return
         }
diff --git a/Sources/Sub2APIStatusBar/LoginViews.swift b/Sources/Sub2APIStatusBar/LoginViews.swift
index 0229e62..684dffc 100644
--- a/Sources/Sub2APIStatusBar/LoginViews.swift
+++ b/Sources/Sub2APIStatusBar/LoginViews.swift
@@ -139,7 +139,8 @@ struct LoginPanel: View {
     private var checklist: OnboardingChecklist {
         OnboardingChecklist.make(
             form: formState,
-            manualToken: model.settingsDraft.authToken
+            manualToken: model.settingsDraft.authToken,
+            language: model.settingsDraft.language
         )
     }
 
diff --git a/Sources/Sub2APIStatusBar/MonitorPanel.swift b/Sources/Sub2APIStatusBar/MonitorPanel.swift
index 02595f2..922641c 100644
--- a/Sources/Sub2APIStatusBar/MonitorPanel.swift
+++ b/Sources/Sub2APIStatusBar/MonitorPanel.swift
@@ -300,7 +300,8 @@ struct MonitorPanel: View {
             subscriptionSummary: model.snapshot.subscriptionSummary,
             trend: model.snapshot.trend,
             models: model.snapshot.modelDistribution,
-            thresholds: model.config.insightThresholds
+            thresholds: model.config.insightThresholds,
+            language: model.config.language
         )
     }
 
diff --git a/Sources/Sub2APIStatusBar/MonitorViewModel.swift b/Sources/Sub2APIStatusBar/MonitorViewModel.swift
index 83bbf3f..416e74c 100644
--- a/Sources/Sub2APIStatusBar/MonitorViewModel.swift
+++ b/Sources/Sub2APIStatusBar/MonitorViewModel.swift
@@ -315,7 +315,8 @@ final class MonitorViewModel: ObservableObject {
             config: config,
             snapshot: snapshot,
             appVersion: currentAppVersion,
-            notificationAuthorization: notificationAuthorization
+            notificationAuthorization: notificationAuthorization,
+            language: config.language
         )
         NSPasteboard.general.clearContents()
         NSPasteboard.general.setString(report, forType: .string)
@@ -326,7 +327,8 @@ final class MonitorViewModel: ObservableObject {
         let report = SupportBundleReport.make(
             config: config,
             snapshot: snapshot,
-            appVersion: currentAppVersion
+            appVersion: currentAppVersion,
+            language: config.language
         )
         NSPasteboard.general.clearContents()
         NSPasteboard.general.setString(report, forType: .string)
@@ -337,7 +339,8 @@ final class MonitorViewModel: ObservableObject {
         let report = UsageReport.make(
             config: config,
             snapshot: snapshot,
-            now: now
+            now: now,
+            language: config.language
         )
         NSPasteboard.general.clearContents()
         NSPasteboard.general.setString(report, forType: .string)
@@ -348,7 +351,8 @@ final class MonitorViewModel: ObservableObject {
         let summary = SocialShareSummary.make(
             config: config,
             snapshot: snapshot,
-            now: now
+            now: now,
+            language: config.language
         )
         let pasteboard = NSPasteboard.general
         pasteboard.clearContents()
@@ -365,7 +369,8 @@ final class MonitorViewModel: ObservableObject {
         let summary = SocialShareSummary.make(
             config: config,
             snapshot: snapshot,
-            now: now
+            now: now,
+            language: config.language
         )
         var components = URLComponents(string: "https://twitter.com/intent/tweet")
         components?.queryItems = [
@@ -406,7 +411,8 @@ final class MonitorViewModel: ObservableObject {
         RecoverySuggestion.make(
             message: settingsError,
             hasBaseURL: !settingsDraft.baseURL.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty,
-            hasToken: !settingsDraft.authToken.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty
+            hasToken: !settingsDraft.authToken.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty,
+            language: settingsDraft.language
         )
     }
 
@@ -417,7 +423,8 @@ final class MonitorViewModel: ObservableObject {
         return RecoverySuggestion.make(
             message: snapshot.message,
             hasBaseURL: !config.baseURL.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty,
-            hasToken: !config.authToken.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty
+            hasToken: !config.authToken.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty,
+            language: config.language
         )
     }
 
@@ -454,7 +461,8 @@ final class MonitorViewModel: ObservableObject {
             subscriptionSummary: snapshot.subscriptionSummary,
             trend: snapshot.trend,
             models: snapshot.modelDistribution,
-            thresholds: config.insightThresholds
+            thresholds: config.insightThresholds,
+            language: config.language
         )
         insightNotifier.handle(insights: insights, settings: config.insightAlertSettings)
     }
@@ -492,7 +500,8 @@ final class MonitorViewModel: ObservableObject {
             snapshot,
             refreshIntervalSeconds: config.refreshIntervalSeconds,
             settings: config.insightAlertSettings,
-            now: now
+            now: now,
+            language: config.language
         )
     }
 
diff --git a/Sources/Sub2APIStatusCore/DiagnosticReport.swift b/Sources/Sub2APIStatusCore/DiagnosticReport.swift
index b3a0221..3db8648 100644
--- a/Sources/Sub2APIStatusCore/DiagnosticReport.swift
+++ b/Sources/Sub2APIStatusCore/DiagnosticReport.swift
@@ -6,51 +6,55 @@ public enum DiagnosticReport {
         snapshot: MonitorSnapshot,
         appVersion: String,
         notificationAuthorization: InsightNotificationAuthorization? = nil,
-        osVersion: String = ProcessInfo.processInfo.operatingSystemVersionString
+        osVersion: String = ProcessInfo.processInfo.operatingSystemVersionString,
+        language: AppLanguage? = nil
     ) -> String {
         let now = Date()
+        let strings = AppStrings(language: language ?? .en)
+        let reportLanguage = language ?? .en
         let isStale = snapshot.isStale(now: now, refreshIntervalSeconds: config.refreshIntervalSeconds)
         var lines = [
-            "Sub2API Status Bar Diagnostics",
-            "Version: \(appVersion)",
+            strings.text(en: "Sub2API Status Bar Diagnostics", zhHans: "Sub2API Status Bar 诊断"),
+            "\(strings.text(en: "Version", zhHans: "版本")): \(appVersion)",
             "OS: \(osVersion)",
-            "Status: \(snapshot.statusLabel(now: now, refreshIntervalSeconds: config.refreshIntervalSeconds))",
-            "Connected: \(snapshot.connected ? "yes" : "no")",
-            "Data Freshness: \(isStale ? "stale" : "fresh")",
-            "Base URL: \(config.baseURL)",
-            "Refresh Interval: \(Int(config.refreshIntervalSeconds))s",
-            "Menu Bar Text: \(config.showsMenuBarText ? "shown" : "hidden")",
-            "Menu Bar Metric: \(config.menuBarMetric.rawValue)",
-            "Insight Alerts: \(config.insightAlertSettings.isEnabled ? "enabled" : "disabled")",
-            "Insight Alert Level: \(config.insightAlertSettings.minimumSeverity.rawValue)",
-            "Insight Alert Cooldown: \(Int(config.insightAlertSettings.cooldownMinutes))m",
-            "Monthly Budget: \(StatusFormatters.currency(config.insightThresholds.monthlyBudgetUSD))",
-            "Spend Surge Threshold: \(Int(config.insightThresholds.spendSurgeRatio * 100))%",
-            "Notification Permission: \(notificationAuthorization?.rawValue ?? "unknown")",
-            "Accounts: \(config.accounts.count)",
-            "Selected Account: \(config.selectedAccount?.displayName ?? "none")",
-            "Access Token: \(config.authToken.isEmpty ? "missing" : "present")",
-            "Refresh Token: \(config.refreshToken.isEmpty ? "missing" : "present")",
+            "\(strings.status): \(snapshot.statusLabel(now: now, refreshIntervalSeconds: config.refreshIntervalSeconds, language: reportLanguage))",
+            "\(strings.text(en: "Connected", zhHans: "连接状态")): \(yesNo(snapshot.connected, strings: strings))",
+            "\(strings.text(en: "Data Freshness", zhHans: "数据新鲜度")): \(isStale ? strings.text(en: "stale", zhHans: "过期") : strings.text(en: "fresh", zhHans: "新鲜"))",
+            "\(strings.baseURL): \(config.baseURL)",
+            "\(strings.text(en: "Refresh Interval", zhHans: "刷新间隔")): \(Int(config.refreshIntervalSeconds))s",
+            "\(strings.text(en: "Menu Bar Text", zhHans: "菜单栏文字")): \(config.showsMenuBarText ? strings.text(en: "shown", zhHans: "显示") : strings.text(en: "hidden", zhHans: "隐藏"))",
+            "\(strings.text(en: "Menu Bar Metric", zhHans: "菜单栏指标")): \(config.menuBarMetric.rawValue)",
+            "\(strings.text(en: "Language", zhHans: "语言")): \(config.language.rawValue)",
+            "\(strings.text(en: "Insight Alerts", zhHans: "洞察提醒")): \(config.insightAlertSettings.isEnabled ? strings.text(en: "enabled", zhHans: "已开启") : strings.text(en: "disabled", zhHans: "已关闭"))",
+            "\(strings.text(en: "Insight Alert Level", zhHans: "洞察提醒级别")): \(config.insightAlertSettings.minimumSeverity.rawValue)",
+            "\(strings.text(en: "Insight Alert Cooldown", zhHans: "洞察提醒冷却")): \(Int(config.insightAlertSettings.cooldownMinutes))m",
+            "\(strings.text(en: "Monthly Budget", zhHans: "月度预算")): \(StatusFormatters.currency(config.insightThresholds.monthlyBudgetUSD))",
+            "\(strings.text(en: "Spend Surge Threshold", zhHans: "花费激增阈值")): \(Int(config.insightThresholds.spendSurgeRatio * 100))%",
+            "\(strings.text(en: "Notification Permission", zhHans: "通知权限")): \(notificationAuthorization?.rawValue ?? strings.text(en: "unknown", zhHans: "未知"))",
+            "\(strings.accounts): \(config.accounts.count)",
+            "\(strings.text(en: "Selected Account", zhHans: "当前账户")): \(config.selectedAccount?.displayName ?? strings.text(en: "none", zhHans: "无"))",
+            "\(strings.text(en: "Access Token", zhHans: "访问令牌")): \(config.authToken.isEmpty ? strings.text(en: "missing", zhHans: "缺失") : strings.text(en: "present", zhHans: "存在"))",
+            "\(strings.text(en: "Refresh Token", zhHans: "刷新令牌")): \(config.refreshToken.isEmpty ? strings.text(en: "missing", zhHans: "缺失") : strings.text(en: "present", zhHans: "存在"))",
         ]
 
         if let stats = snapshot.stats {
-            lines.append("Today Requests: \(stats.todayRequests)")
-            lines.append("Today Cost: \(StatusFormatters.preciseCurrency(stats.todayActualCost))")
-            lines.append("Today Tokens: \(stats.todayTokens)")
-            lines.append("Today Cost per MTok: \(StatusFormatters.costPerMillionTokens(cost: stats.todayActualCost, tokens: stats.todayTokens))")
-            lines.append("Total Tokens: \(stats.totalTokens)")
+            lines.append("\(strings.text(en: "Today Requests", zhHans: "今日请求")): \(stats.todayRequests)")
+            lines.append("\(strings.text(en: "Today Cost", zhHans: "今日成本")): \(StatusFormatters.preciseCurrency(stats.todayActualCost))")
+            lines.append("\(strings.text(en: "Today Tokens", zhHans: "今日令牌")): \(stats.todayTokens)")
+            lines.append("\(strings.text(en: "Today Cost per MTok", zhHans: "今日每百万令牌成本")): \(StatusFormatters.costPerMillionTokens(cost: stats.todayActualCost, tokens: stats.todayTokens))")
+            lines.append("\(strings.text(en: "Total Tokens", zhHans: "总令牌")): \(stats.totalTokens)")
             lines.append("RPM: \(StatusFormatters.menuBarRate(stats.rpm))")
             lines.append("TPM: \(StatusFormatters.compactNumber(Int64(stats.tpm)))")
         }
 
         if let subscriptionSummary = snapshot.subscriptionSummary {
-            lines.append("Active Subscriptions: \(subscriptionSummary.activeCount)")
-            lines.append("Highest Quota Usage: \(StatusFormatters.percent(subscriptionSummary.highestProgress))")
-            lines.append("Expiring Soon: \(subscriptionSummary.expiringSoonCount)")
+            lines.append("\(strings.text(en: "Active Subscriptions", zhHans: "活跃订阅")): \(subscriptionSummary.activeCount)")
+            lines.append("\(strings.text(en: "Highest Quota Usage", zhHans: "最高配额用量")): \(StatusFormatters.percent(subscriptionSummary.highestProgress))")
+            lines.append("\(strings.text(en: "Expiring Soon", zhHans: "即将过期")): \(subscriptionSummary.expiringSoonCount)")
         }
 
         if let models = snapshot.modelDistribution {
-            lines.append("Visible Models: \(models.prefix(5).map(\.model).joined(separator: ", "))")
+            lines.append("\(strings.text(en: "Visible Models", zhHans: "可见模型")): \(models.prefix(5).map(\.model).joined(separator: ", "))")
         }
 
         if snapshot.connected {
@@ -60,22 +64,27 @@ public enum DiagnosticReport {
                 subscriptionSummary: snapshot.subscriptionSummary,
                 trend: snapshot.trend,
                 models: snapshot.modelDistribution,
-                thresholds: config.insightThresholds
+                thresholds: config.insightThresholds,
+                language: reportLanguage
             )
-            lines.append("Usage Insight: \(insights.headline)")
+            lines.append("\(strings.text(en: "Usage Insight", zhHans: "用量洞察")): \(insights.headline)")
             for item in insights.items {
-                lines.append("Insight \(item.title): \(item.value) - \(item.detail)")
+                lines.append("\(strings.text(en: "Insight", zhHans: "洞察")) \(item.title): \(item.value) - \(item.detail)")
             }
         }
 
         if let lastUpdatedAt = snapshot.lastUpdatedAt {
-            lines.append("Last Updated: \(ISO8601DateFormatter().string(from: lastUpdatedAt))")
+            lines.append("\(strings.text(en: "Last Updated", zhHans: "上次更新")): \(ISO8601DateFormatter().string(from: lastUpdatedAt))")
         }
 
         if let message = snapshot.message, !message.isEmpty {
-            lines.append("Message: \(message)")
+            lines.append("\(strings.text(en: "Message", zhHans: "消息")): \(message)")
         }
 
         return lines.joined(separator: "\n")
     }
+
+    private static func yesNo(_ value: Bool, strings: AppStrings) -> String {
+        strings.text(en: value ? "yes" : "no", zhHans: value ? "是" : "否")
+    }
 }
diff --git a/Sources/Sub2APIStatusCore/InsightAlertPolicy.swift b/Sources/Sub2APIStatusCore/InsightAlertPolicy.swift
index e5a6140..37c1902 100644
--- a/Sources/Sub2APIStatusCore/InsightAlertPolicy.swift
+++ b/Sources/Sub2APIStatusCore/InsightAlertPolicy.swift
@@ -30,7 +30,8 @@ public struct InsightAlertPolicy: Equatable, Sendable {
     public func nextAlert(
         from insights: UsageInsights,
         lastAlertedAtByFingerprint: [String: Date],
-        now: Date
+        now: Date,
+        language: AppLanguage = .en
     ) -> InsightAlert? {
         guard settings.isEnabled else {
             return nil
@@ -59,8 +60,10 @@ public struct InsightAlertPolicy: Equatable, Sendable {
         from snapshot: MonitorSnapshot,
         refreshIntervalSeconds: Double,
         lastAlertedAtByFingerprint: [String: Date],
-        now: Date
+        now: Date,
+        language: AppLanguage = .en
     ) -> InsightAlert? {
+        let strings = AppStrings(language: language)
         guard settings.isEnabled,
               MonitorSeverity.warning.sortRank >= settings.minimumSeverity.sortRank,
               snapshot.isStale(now: now, refreshIntervalSeconds: refreshIntervalSeconds),
@@ -76,8 +79,8 @@ public struct InsightAlertPolicy: Equatable, Sendable {
 
         return InsightAlert(
             fingerprint: fingerprint,
-            title: "Stale Data",
-            body: "Sub2API usage has not refreshed for \(StatusFormatters.duration(seconds: now.timeIntervalSince(lastUpdatedAt))). Check the server or retry refresh.",
+            title: strings.staleData,
+            body: strings.text(en: "Sub2API usage has not refreshed for \(StatusFormatters.duration(seconds: now.timeIntervalSince(lastUpdatedAt))). Check the server or retry refresh.", zhHans: "Sub2API 用量已 \(StatusFormatters.duration(seconds: now.timeIntervalSince(lastUpdatedAt))) 未刷新。请检查服务器或重试刷新。"),
             severity: .warning
         )
     }
@@ -111,12 +114,14 @@ public struct InsightNotificationPermissionSummary: Equatable, Sendable {
 
     public static func make(
         settings: InsightAlertSettings,
-        authorization: InsightNotificationAuthorization
+        authorization: InsightNotificationAuthorization,
+        language: AppLanguage = .en
     ) -> InsightNotificationPermissionSummary {
+        let strings = AppStrings(language: language)
         guard settings.isEnabled else {
             return InsightNotificationPermissionSummary(
-                title: "Alerts off",
-                detail: "Turn on insight alerts to receive local notifications.",
+                title: strings.text(en: "Alerts off", zhHans: "提醒已关闭"),
+                detail: strings.text(en: "Turn on insight alerts to receive local notifications.", zhHans: "开启洞察提醒以接收本地通知。"),
                 action: nil
             )
         }
@@ -124,20 +129,20 @@ public struct InsightNotificationPermissionSummary: Equatable, Sendable {
         switch authorization {
         case .authorized:
             return InsightNotificationPermissionSummary(
-                title: "Notifications ready",
-                detail: "macOS alerts can be delivered for \(settings.minimumSeverity.rawValue) insights.",
+                title: strings.text(en: "Notifications ready", zhHans: "通知已就绪"),
+                detail: strings.text(en: "macOS alerts can be delivered for \(settings.minimumSeverity.rawValue) insights.", zhHans: "macOS 可发送 \(settings.minimumSeverity.rawValue) 级别洞察提醒。"),
                 action: nil
             )
         case .notDetermined:
             return InsightNotificationPermissionSummary(
-                title: "Permission needed",
-                detail: "Allow notifications so Sub2API can warn you when usage needs attention.",
+                title: strings.text(en: "Permission needed", zhHans: "需要通知权限"),
+                detail: strings.text(en: "Allow notifications so Sub2API can warn you when usage needs attention.", zhHans: "允许通知后，Sub2API 可在用量需要关注时提醒你。"),
                 action: .requestPermission
             )
         case .denied:
             return InsightNotificationPermissionSummary(
-                title: "Notifications blocked",
-                detail: "Open macOS notification settings and allow Sub2API alerts.",
+                title: strings.text(en: "Notifications blocked", zhHans: "通知被阻止"),
+                detail: strings.text(en: "Open macOS notification settings and allow Sub2API alerts.", zhHans: "打开 macOS 通知设置并允许 Sub2API 提醒。"),
                 action: .openSystemSettings
             )
         }
diff --git a/Sources/Sub2APIStatusCore/Models.swift b/Sources/Sub2APIStatusCore/Models.swift
index 311b523..1f9404c 100644
--- a/Sources/Sub2APIStatusCore/Models.swift
+++ b/Sources/Sub2APIStatusCore/Models.swift
@@ -1129,33 +1129,38 @@ public struct MonitorSnapshot: Equatable, Sendable {
     }
 
     public func statusLabel(now: Date, refreshIntervalSeconds: Double?) -> String {
+        statusLabel(now: now, refreshIntervalSeconds: refreshIntervalSeconds, language: .en)
+    }
+
+    public func statusLabel(now: Date, refreshIntervalSeconds: Double?, language: AppLanguage) -> String {
+        let strings = AppStrings(language: language)
         if !connected {
-            return "Disconnected"
+            return strings.disconnected
         }
 
         if isStale(now: now, refreshIntervalSeconds: refreshIntervalSeconds) {
-            return "Stale Data"
+            return strings.staleData
         }
 
         if let subscriptionSummary {
             if subscriptionSummary.highestProgress >= 0.95 {
-                return "Near Limit"
+                return strings.text(en: "Near Limit", zhHans: "接近上限")
             }
             if subscriptionSummary.highestProgress >= 0.8 {
-                return "High Usage"
+                return strings.text(en: "High Usage", zhHans: "高用量")
             }
             if subscriptionSummary.expiringSoonCount > 0 {
-                return "Expiring Soon"
+                return strings.text(en: "Expiring Soon", zhHans: "即将过期")
             }
         }
 
         return switch severity(now: now, refreshIntervalSeconds: refreshIntervalSeconds) {
         case .healthy:
-            "OK"
+            strings.text(en: "OK", zhHans: "正常")
         case .warning:
-            "Warn"
+            strings.text(en: "Warn", zhHans: "警告")
         case .error:
-            "Error"
+            strings.error
         }
     }
 
@@ -1172,47 +1177,57 @@ public struct MonitorSnapshot: Equatable, Sendable {
         now: Date,
         refreshIntervalSeconds: Double?
     ) -> String {
+        menuBarSummary(metric: metric, now: now, refreshIntervalSeconds: refreshIntervalSeconds, language: .en)
+    }
+
+    public func menuBarSummary(
+        metric: MenuBarMetric,
+        now: Date,
+        refreshIntervalSeconds: Double?,
+        language: AppLanguage
+    ) -> String {
+        let strings = AppStrings(language: language)
         guard connected else {
-            return "Sub2API \(statusLabel(now: now, refreshIntervalSeconds: refreshIntervalSeconds))"
+            return "Sub2API \(statusLabel(now: now, refreshIntervalSeconds: refreshIntervalSeconds, language: language))"
         }
 
-        let prefix = isStale(now: now, refreshIntervalSeconds: refreshIntervalSeconds) ? "Stale · " : ""
+        let prefix = isStale(now: now, refreshIntervalSeconds: refreshIntervalSeconds) ? strings.text(en: "Stale · ", zhHans: "过期 · ") : ""
 
         if metric == .quota, let subscriptionSummary {
-            return "\(prefix)\(StatusFormatters.percent(subscriptionSummary.highestProgress)) quota · \(subscriptionSummary.activeCount) subs"
+            return strings.text(en: "\(prefix)\(StatusFormatters.percent(subscriptionSummary.highestProgress)) quota · \(subscriptionSummary.activeCount) subs", zhHans: "\(prefix)\(StatusFormatters.percent(subscriptionSummary.highestProgress)) 配额 · \(subscriptionSummary.activeCount) 订阅")
         }
 
         if let stats {
             switch metric {
             case .automatic:
-                return "\(prefix)\(StatusFormatters.currency(stats.todayActualCost)) · \(StatusFormatters.menuBarCount(stats.todayRequests)) req · \(StatusFormatters.menuBarRate(stats.rpm)) RPM"
+                return strings.text(en: "\(prefix)\(StatusFormatters.currency(stats.todayActualCost)) · \(StatusFormatters.menuBarCount(stats.todayRequests)) req · \(StatusFormatters.menuBarRate(stats.rpm)) RPM", zhHans: "\(prefix)\(StatusFormatters.currency(stats.todayActualCost)) · \(StatusFormatters.menuBarCount(stats.todayRequests)) 请求 · \(StatusFormatters.menuBarRate(stats.rpm)) RPM")
             case .spend:
-                return "\(prefix)\(StatusFormatters.currency(stats.todayActualCost)) · \(StatusFormatters.menuBarCount(stats.todayRequests)) req"
+                return strings.text(en: "\(prefix)\(StatusFormatters.currency(stats.todayActualCost)) · \(StatusFormatters.menuBarCount(stats.todayRequests)) req", zhHans: "\(prefix)\(StatusFormatters.currency(stats.todayActualCost)) · \(StatusFormatters.menuBarCount(stats.todayRequests)) 请求")
             case .balance:
                 if let balance = currentUser?.balance {
                     if stats.todayActualCost > 0 {
                         return "\(prefix)\(StatusFormatters.currency(balance)) · \(String(format: "%.1fd", balance / stats.todayActualCost))"
                     }
-                    return "\(prefix)\(StatusFormatters.currency(balance)) · no spend"
+                    return strings.text(en: "\(prefix)\(StatusFormatters.currency(balance)) · no spend", zhHans: "\(prefix)\(StatusFormatters.currency(balance)) · 无花费")
                 }
-                return "\(prefix)\(StatusFormatters.currency(stats.todayActualCost)) · no balance"
+                return strings.text(en: "\(prefix)\(StatusFormatters.currency(stats.todayActualCost)) · no balance", zhHans: "\(prefix)\(StatusFormatters.currency(stats.todayActualCost)) · 无余额")
             case .quota:
                 if let subscriptionSummary {
-                    return "\(prefix)\(StatusFormatters.percent(subscriptionSummary.highestProgress)) quota · \(subscriptionSummary.activeCount) subs"
+                    return strings.text(en: "\(prefix)\(StatusFormatters.percent(subscriptionSummary.highestProgress)) quota · \(subscriptionSummary.activeCount) subs", zhHans: "\(prefix)\(StatusFormatters.percent(subscriptionSummary.highestProgress)) 配额 · \(subscriptionSummary.activeCount) 订阅")
                 }
-                return "\(prefix)\(StatusFormatters.currency(stats.todayActualCost)) · no quota"
+                return strings.text(en: "\(prefix)\(StatusFormatters.currency(stats.todayActualCost)) · no quota", zhHans: "\(prefix)\(StatusFormatters.currency(stats.todayActualCost)) · 无配额")
             case .tokens:
-                return "\(prefix)\(StatusFormatters.compactNumber(stats.todayTokens)) tok · \(StatusFormatters.compactNumber(Int64(stats.tpm))) TPM"
+                return strings.text(en: "\(prefix)\(StatusFormatters.compactNumber(stats.todayTokens)) tok · \(StatusFormatters.compactNumber(Int64(stats.tpm))) TPM", zhHans: "\(prefix)\(StatusFormatters.compactNumber(stats.todayTokens)) 令牌 · \(StatusFormatters.compactNumber(Int64(stats.tpm))) TPM")
             case .requests:
-                return "\(prefix)\(StatusFormatters.menuBarCount(stats.todayRequests)) req · \(StatusFormatters.menuBarRate(stats.rpm)) RPM"
+                return strings.text(en: "\(prefix)\(StatusFormatters.menuBarCount(stats.todayRequests)) req · \(StatusFormatters.menuBarRate(stats.rpm)) RPM", zhHans: "\(prefix)\(StatusFormatters.menuBarCount(stats.todayRequests)) 请求 · \(StatusFormatters.menuBarRate(stats.rpm)) RPM")
             }
         }
 
         if let subscriptionSummary {
-            return "\(prefix)\(subscriptionSummary.activeCount) subs · \(StatusFormatters.percent(subscriptionSummary.highestProgress)) peak"
+            return strings.text(en: "\(prefix)\(subscriptionSummary.activeCount) subs · \(StatusFormatters.percent(subscriptionSummary.highestProgress)) peak", zhHans: "\(prefix)\(subscriptionSummary.activeCount) 订阅 · 峰值 \(StatusFormatters.percent(subscriptionSummary.highestProgress))")
         }
 
-        return "Sub2API \(statusLabel(now: now, refreshIntervalSeconds: refreshIntervalSeconds))"
+        return "Sub2API \(statusLabel(now: now, refreshIntervalSeconds: refreshIntervalSeconds, language: language))"
     }
 
     public func isStale(now: Date, refreshIntervalSeconds: Double?) -> Bool {
diff --git a/Sources/Sub2APIStatusCore/OnboardingChecklist.swift b/Sources/Sub2APIStatusCore/OnboardingChecklist.swift
index 111a091..6c537d3 100644
--- a/Sources/Sub2APIStatusCore/OnboardingChecklist.swift
+++ b/Sources/Sub2APIStatusCore/OnboardingChecklist.swift
@@ -23,7 +23,8 @@ public struct OnboardingChecklist: Equatable, Sendable {
         self.summary = summary
     }
 
-    public static func make(form: LoginFormState, manualToken: String) -> OnboardingChecklist {
+    public static func make(form: LoginFormState, manualToken: String, language: AppLanguage = .en) -> OnboardingChecklist {
+        let strings = AppStrings(language: language)
         let hasURL = !form.baseURL.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty
         let hasAccount = !form.email.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty
         let hasPassword = !form.password.isEmpty
@@ -32,35 +33,35 @@ public struct OnboardingChecklist: Equatable, Sendable {
         let steps = [
             OnboardingStep(
                 id: "server-url",
-                title: "Server URL",
-                detail: "Root Sub2API address; /api/v1 is added automatically.",
+                title: strings.serverURL,
+                detail: strings.text(en: "Root Sub2API address; /api/v1 is added automatically.", zhHans: "Sub2API 根地址；/api/v1 会自动添加。"),
                 isComplete: hasURL
             ),
             OnboardingStep(
                 id: "account",
-                title: "Account",
-                detail: hasToken ? "Manual token can be saved without email login." : "Email used for Sub2API login.",
+                title: strings.account,
+                detail: hasToken ? strings.text(en: "Manual token can be saved without email login.", zhHans: "手动令牌无需邮箱登录即可保存。") : strings.text(en: "Email used for Sub2API login.", zhHans: "用于 Sub2API 登录的邮箱。"),
                 isComplete: hasAccount || hasToken
             ),
             OnboardingStep(
                 id: "credential",
-                title: "Password or token",
-                detail: "Login with a password, or paste a bearer token.",
+                title: strings.text(en: "Password or token", zhHans: "密码或令牌"),
+                detail: strings.text(en: "Login with a password, or paste a bearer token.", zhHans: "使用密码登录，或粘贴 bearer 令牌。"),
                 isComplete: hasPassword || hasToken
             ),
         ]
 
         let summary: String
         if hasURL, hasToken {
-            summary = "Ready to save token."
+            summary = strings.text(en: "Ready to save token.", zhHans: "可以保存令牌。")
         } else if form.canSubmit {
-            summary = "Ready to login."
+            summary = strings.text(en: "Ready to login.", zhHans: "可以登录。")
         } else {
             let missing = steps
                 .filter { !$0.isComplete }
-                .map(\.summaryName)
-                .joined(separator: ", ")
-            summary = "Add \(missing)."
+                .map { $0.summaryName(language: language) }
+                .joined(separator: strings.text(en: ", ", zhHans: "、"))
+            summary = strings.text(en: "Add \(missing).", zhHans: "请补充\(missing)。")
         }
 
         return OnboardingChecklist(steps: steps, summary: summary)
@@ -68,12 +69,15 @@ public struct OnboardingChecklist: Equatable, Sendable {
 }
 
 private extension OnboardingStep {
-    var summaryName: String {
+    func summaryName(language: AppLanguage) -> String {
+        let strings = AppStrings(language: language)
         switch id {
         case "server-url":
-            "server URL"
+            return strings.text(en: "server URL", zhHans: "服务器 URL")
+        case "credential":
+            return strings.text(en: "password or token", zhHans: "密码或令牌")
         default:
-            title.lowercased()
+            return strings.text(en: title.lowercased(), zhHans: title)
         }
     }
 }
diff --git a/Sources/Sub2APIStatusCore/RecoverySuggestion.swift b/Sources/Sub2APIStatusCore/RecoverySuggestion.swift
index 362caaa..4b557e6 100644
--- a/Sources/Sub2APIStatusCore/RecoverySuggestion.swift
+++ b/Sources/Sub2APIStatusCore/RecoverySuggestion.swift
@@ -33,27 +33,28 @@ public struct RecoverySuggestion: Equatable, Sendable {
         self.actions = actions
     }
 
-    public static func make(message: String?, hasBaseURL: Bool, hasToken: Bool) -> RecoverySuggestion {
+    public static func make(message: String?, hasBaseURL: Bool, hasToken: Bool, language: AppLanguage = .en) -> RecoverySuggestion {
+        let strings = AppStrings(language: language)
         let normalized = (message ?? "").lowercased()
 
         if !hasBaseURL || normalized.contains("base url") || normalized.contains("url is invalid") {
             return RecoverySuggestion(
-                title: "Add your server URL",
-                detail: "Use the root Sub2API server address. The app adds /api/v1 automatically.",
+                title: strings.text(en: "Add your server URL", zhHans: "添加服务器 URL"),
+                detail: strings.text(en: "Use the root Sub2API server address. The app adds /api/v1 automatically.", zhHans: "使用 Sub2API 服务器根地址，App 会自动添加 /api/v1。"),
                 actions: [
-                    RecoveryAction(kind: .enterURL, label: "Enter URL", systemImage: "link"),
-                    RecoveryAction(kind: .openServer, label: "Open Server", systemImage: "safari"),
+                    RecoveryAction(kind: .enterURL, label: strings.text(en: "Enter URL", zhHans: "输入 URL"), systemImage: "link"),
+                    RecoveryAction(kind: .openServer, label: strings.openServer, systemImage: "safari"),
                 ]
             )
         }
 
         if normalized.contains("401") || normalized.contains("unauthorized") || normalized.contains("expired") {
             return RecoverySuggestion(
-                title: "Sign in again",
-                detail: "Your saved session is no longer accepted. Login again or replace the bearer token.",
+                title: strings.text(en: "Sign in again", zhHans: "重新登录"),
+                detail: strings.text(en: "Your saved session is no longer accepted. Login again or replace the bearer token.", zhHans: "已保存的会话不再被接受。请重新登录或替换 bearer 令牌。"),
                 actions: [
-                    RecoveryAction(kind: .login, label: "Login", systemImage: "key.fill"),
-                    RecoveryAction(kind: .replaceToken, label: "Replace Token", systemImage: "square.and.pencil"),
+                    RecoveryAction(kind: .login, label: strings.login, systemImage: "key.fill"),
+                    RecoveryAction(kind: .replaceToken, label: strings.text(en: "Replace Token", zhHans: "替换令牌"), systemImage: "square.and.pencil"),
                 ]
             )
         }
@@ -64,32 +65,32 @@ public struct RecoverySuggestion: Equatable, Sendable {
             || normalized.contains("offline")
             || normalized.contains("cannot find host") {
             return RecoverySuggestion(
-                title: "Check server reachability",
-                detail: "Open the Sub2API server in your browser, then retry when it responds.",
+                title: strings.text(en: "Check server reachability", zhHans: "检查服务器可达性"),
+                detail: strings.text(en: "Open the Sub2API server in your browser, then retry when it responds.", zhHans: "在浏览器中打开 Sub2API 服务器，确认响应后重试。"),
                 actions: [
-                    RecoveryAction(kind: .openServer, label: "Open Server", systemImage: "safari"),
-                    RecoveryAction(kind: .retry, label: "Retry", systemImage: "arrow.clockwise"),
+                    RecoveryAction(kind: .openServer, label: strings.openServer, systemImage: "safari"),
+                    RecoveryAction(kind: .retry, label: strings.text(en: "Retry", zhHans: "重试"), systemImage: "arrow.clockwise"),
                 ]
             )
         }
 
         if !hasToken {
             return RecoverySuggestion(
-                title: "Connect an account",
-                detail: "Login with your Sub2API account or paste a bearer token to start monitoring.",
+                title: strings.text(en: "Connect an account", zhHans: "连接账户"),
+                detail: strings.text(en: "Login with your Sub2API account or paste a bearer token to start monitoring.", zhHans: "使用 Sub2API 账户登录，或粘贴 bearer 令牌以开始监控。"),
                 actions: [
-                    RecoveryAction(kind: .login, label: "Login", systemImage: "key.fill"),
-                    RecoveryAction(kind: .replaceToken, label: "Use Token", systemImage: "square.and.pencil"),
+                    RecoveryAction(kind: .login, label: strings.login, systemImage: "key.fill"),
+                    RecoveryAction(kind: .replaceToken, label: strings.text(en: "Use Token", zhHans: "使用令牌"), systemImage: "square.and.pencil"),
                 ]
             )
         }
 
         return RecoverySuggestion(
-            title: "Refresh or inspect settings",
-            detail: "Retry the request. If it still fails, check the server URL and token in Settings.",
+            title: strings.text(en: "Refresh or inspect settings", zhHans: "刷新或检查设置"),
+            detail: strings.text(en: "Retry the request. If it still fails, check the server URL and token in Settings.", zhHans: "重试请求。如果仍失败，请检查设置中的服务器 URL 和令牌。"),
             actions: [
-                RecoveryAction(kind: .retry, label: "Retry", systemImage: "arrow.clockwise"),
-                RecoveryAction(kind: .openServer, label: "Open Server", systemImage: "safari"),
+                RecoveryAction(kind: .retry, label: strings.text(en: "Retry", zhHans: "重试"), systemImage: "arrow.clockwise"),
+                RecoveryAction(kind: .openServer, label: strings.openServer, systemImage: "safari"),
             ]
         )
     }
diff --git a/Sources/Sub2APIStatusCore/SocialShareSummary.swift b/Sources/Sub2APIStatusCore/SocialShareSummary.swift
index 57e7ca0..bf476dc 100644
--- a/Sources/Sub2APIStatusCore/SocialShareSummary.swift
+++ b/Sources/Sub2APIStatusCore/SocialShareSummary.swift
@@ -22,12 +22,14 @@ public struct SocialShareSummary: Equatable, Sendable {
     public static func make(
         config: AppConfig,
         snapshot: MonitorSnapshot,
-        now: Date = Date()
+        now: Date = Date(),
+        language: AppLanguage? = nil
     ) -> SocialShareSummary {
+        let strings = AppStrings(language: language ?? .en)
         let stats = snapshot.stats
-        let topModel = topModelText(snapshot.modelDistribution)
-        let quota = topQuotaText(snapshot.subscriptionSummary)
-        let trend = trendText(snapshot.trend)
+        let topModel = topModelText(snapshot.modelDistribution, strings: strings)
+        let quota = topQuotaText(snapshot.subscriptionSummary, strings: strings)
+        let trend = trendText(snapshot.trend, strings: strings)
         let unitCost = StatusFormatters.costPerMillionTokens(
             cost: stats?.todayActualCost ?? 0,
             tokens: stats?.todayTokens ?? 0
@@ -39,31 +41,32 @@ public struct SocialShareSummary: Equatable, Sendable {
         let tokens = StatusFormatters.compactNumber(todayTokens)
         let spend = StatusFormatters.currency(stats?.todayActualCost ?? 0)
         let requests = StatusFormatters.menuBarCount(stats?.todayRequests ?? 0)
-        let persona = "Build Log"
-        let punchline = punchlineText(tokens: tokens, todayTokens: todayTokens)
-        let privacy = "No prompts. No keys."
+        let persona = strings.text(en: "Build Log", zhHans: "构建日志")
+        let punchline = punchlineText(tokens: tokens, todayTokens: todayTokens, strings: strings)
+        let privacy = strings.text(en: "No prompts. No keys.", zhHans: "不含提示词。不含密钥。")
         let badges = [
             spend,
-            topModelBadgeText(snapshot.modelDistribution),
-            quotaBadgeText(snapshot.subscriptionSummary),
+            topModelBadgeText(snapshot.modelDistribution, strings: strings),
+            quotaBadgeText(snapshot.subscriptionSummary, strings: strings),
         ]
 
         let title = todayTokens > 0
-            ? "\(tokens) AI tokens today"
-            : "My AI usage receipt"
-        let tagline = "A public-safe AI work counter."
+            ? strings.text(en: "\(tokens) AI tokens today", zhHans: "今日 \(tokens) AI 令牌")
+            : strings.text(en: "My AI usage receipt", zhHans: "我的 AI 用量小票")
+        let tagline = strings.text(en: "A public-safe AI work counter.", zhHans: "一张可公开分享的 AI 工作计数卡。")
+        let primaryLabel = strings.text(en: "AI tokens today", zhHans: "今日 AI 令牌")
 
         let lines = [
             title,
             persona,
             punchline,
-            "\(spend) spend | \(requests) requests | \(unitCost)",
-            "Top model: \(topModel)",
-            "Quota: \(quota)",
-            "Trend: \(trend)",
+            strings.text(en: "\(spend) spend | \(requests) requests | \(unitCost)", zhHans: "花费 \(spend) | \(requests) 次请求 | \(unitCost)"),
+            strings.text(en: "Top model: \(topModel)", zhHans: "主要模型：\(topModel)"),
+            strings.text(en: "Quota: \(quota)", zhHans: "配额：\(quota)"),
+            strings.text(en: "Trend: \(trend)", zhHans: "趋势：\(trend)"),
             privacy,
-            "Made visible by Sub2API Status Bar.",
-            "#AIUsage #BuildInPublic",
+            strings.text(en: "Made visible by Sub2API Status Bar.", zhHans: "由 Sub2API Status Bar 可视化。"),
+            strings.text(en: "#AIUsage #BuildInPublic", zhHans: "#AI用量 #公开构建"),
         ]
 
         return SocialShareSummary(
@@ -73,7 +76,7 @@ public struct SocialShareSummary: Equatable, Sendable {
             punchlineText: punchline,
             privacyText: privacy,
             primaryMetric: tokens,
-            primaryLabel: "AI tokens today",
+            primaryLabel: primaryLabel,
             spendText: spend,
             requestsText: requests,
             topModelText: topModel,
@@ -87,53 +90,53 @@ public struct SocialShareSummary: Equatable, Sendable {
         )
     }
 
-    private static func punchlineText(tokens: String, todayTokens: Int64) -> String {
+    private static func punchlineText(tokens _: String, todayTokens: Int64, strings: AppStrings) -> String {
         guard todayTokens > 0 else {
-            return "The dashboard is ready for the next run."
+            return strings.text(en: "The dashboard is ready for the next run.", zhHans: "仪表盘已准备好记录下一次运行。")
         }
-        return "The AI work counter for today."
+        return strings.text(en: "The AI work counter for today.", zhHans: "今日 AI 工作计数器。")
     }
 
-    private static func topModelText(_ models: [ModelUsageSummary]?) -> String {
+    private static func topModelText(_ models: [ModelUsageSummary]?, strings: AppStrings) -> String {
         guard let models, let top = models.max(by: { $0.actualCost < $1.actualCost }) else {
-            return "No model data yet"
+            return strings.text(en: "No model data yet", zhHans: "暂无模型数据")
         }
 
         let totalCost = models.map(\.actualCost).reduce(0, +)
         let costShare = totalCost > 0 ? top.actualCost / totalCost : 0
-        return "\(top.model) (\(StatusFormatters.percent(costShare)) cost)"
+        return strings.text(en: "\(top.model) (\(StatusFormatters.percent(costShare)) cost)", zhHans: "\(top.model)（成本占比 \(StatusFormatters.percent(costShare))）")
     }
 
-    private static func topQuotaText(_ summary: SubscriptionSummary?) -> String {
-        guard let quota = topQuota(summary) else {
-            return "No quota pressure"
+    private static func topQuotaText(_ summary: SubscriptionSummary?, strings: AppStrings) -> String {
+        guard let quota = topQuota(summary, strings: strings) else {
+            return strings.text(en: "No quota pressure", zhHans: "暂无配额压力")
         }
 
-        let resetText = quota.resetInSeconds.map { ", resets in \(StatusFormatters.duration(seconds: $0))" } ?? ""
+        let resetText = quota.resetInSeconds.map { strings.text(en: ", resets in \(StatusFormatters.duration(seconds: $0))", zhHans: "，\(StatusFormatters.duration(seconds: $0)) 后重置") } ?? ""
         return "\(quota.name) \(StatusFormatters.percent(quota.progress))\(resetText)"
     }
 
-    private static func quotaBadgeText(_ summary: SubscriptionSummary?) -> String {
-        guard let quota = topQuota(summary) else {
-            return "no quota pressure"
+    private static func quotaBadgeText(_ summary: SubscriptionSummary?, strings: AppStrings) -> String {
+        guard let quota = topQuota(summary, strings: strings) else {
+            return strings.text(en: "no quota pressure", zhHans: "无配额压力")
         }
-        return "\(StatusFormatters.percent(quota.progress)) quota"
+        return strings.text(en: "\(StatusFormatters.percent(quota.progress)) quota", zhHans: "配额 \(StatusFormatters.percent(quota.progress))")
     }
 
-    private static func topModelBadgeText(_ models: [ModelUsageSummary]?) -> String {
+    private static func topModelBadgeText(_ models: [ModelUsageSummary]?, strings: AppStrings) -> String {
         guard let models, let top = models.max(by: { $0.actualCost < $1.actualCost }) else {
-            return "no model data"
+            return strings.text(en: "no model data", zhHans: "无模型数据")
         }
         return top.model
     }
 
-    private static func topQuota(_ summary: SubscriptionSummary?) -> (name: String, progress: Double, resetInSeconds: Double?)? {
+    private static func topQuota(_ summary: SubscriptionSummary?, strings: AppStrings) -> (name: String, progress: Double, resetInSeconds: Double?)? {
         summary?.subscriptions
             .flatMap { item in
                 [
-                    (name: "\(item.groupName) daily", progress: item.dailyProgress, resetInSeconds: item.dailyResetInSeconds),
-                    (name: "\(item.groupName) weekly", progress: item.weeklyProgress, resetInSeconds: item.weeklyResetInSeconds),
-                    (name: "\(item.groupName) monthly", progress: item.monthlyProgress, resetInSeconds: item.monthlyResetInSeconds),
+                    (name: strings.text(en: "\(item.groupName) daily", zhHans: "\(item.groupName) 日配额"), progress: item.dailyProgress, resetInSeconds: item.dailyResetInSeconds),
+                    (name: strings.text(en: "\(item.groupName) weekly", zhHans: "\(item.groupName) 周配额"), progress: item.weeklyProgress, resetInSeconds: item.weeklyResetInSeconds),
+                    (name: strings.text(en: "\(item.groupName) monthly", zhHans: "\(item.groupName) 月配额"), progress: item.monthlyProgress, resetInSeconds: item.monthlyResetInSeconds),
                 ]
             }
             .compactMap { candidate -> (name: String, progress: Double, resetInSeconds: Double?)? in
@@ -145,20 +148,20 @@ public struct SocialShareSummary: Equatable, Sendable {
             .max(by: { $0.progress < $1.progress })
     }
 
-    private static func trendText(_ trend: [TrendDataPoint]?) -> String {
+    private static func trendText(_ trend: [TrendDataPoint]?, strings: AppStrings) -> String {
         guard let trend, trend.count > 1, let latest = trend.last else {
-            return "Collecting baseline"
+            return strings.text(en: "Collecting baseline", zhHans: "正在收集基线")
         }
 
         let previous = trend.dropLast()
         let average = previous.map(\.totalTokens).reduce(0, +) / Int64(max(previous.count, 1))
         guard average > 0 else {
-            return "Collecting baseline"
+            return strings.text(en: "Collecting baseline", zhHans: "正在收集基线")
         }
 
         let delta = (Double(latest.totalTokens) - Double(average)) / Double(average)
         let sign = delta >= 0 ? "+" : ""
-        return "\(sign)\(percentText(abs(delta))) vs \(previous.count)-day avg"
+        return strings.text(en: "\(sign)\(percentText(abs(delta))) vs \(previous.count)-day avg", zhHans: "较 \(previous.count) 日均值 \(sign)\(percentText(abs(delta)))")
     }
 
     private static func skylineValues(_ trend: [TrendDataPoint]?, fallbackTokens: Int64) -> [Double] {
diff --git a/Sources/Sub2APIStatusCore/SupportBundleReport.swift b/Sources/Sub2APIStatusCore/SupportBundleReport.swift
index f38e479..f10dfff 100644
--- a/Sources/Sub2APIStatusCore/SupportBundleReport.swift
+++ b/Sources/Sub2APIStatusCore/SupportBundleReport.swift
@@ -6,62 +6,65 @@ public enum SupportBundleReport {
         snapshot: MonitorSnapshot,
         appVersion: String,
         osVersion: String = ProcessInfo.processInfo.operatingSystemVersionString,
-        installSource: String = "GitHub Release / Homebrew Cask draft / built from source"
+        installSource: String = "GitHub Release / Homebrew Cask draft / built from source",
+        language: AppLanguage? = nil
     ) -> String {
+        let strings = AppStrings(language: language ?? .en)
         let diagnostics = DiagnosticReport.make(
             config: config,
             snapshot: snapshot,
             appVersion: appVersion,
-            osVersion: osVersion
+            osVersion: osVersion,
+            language: language ?? .en
         )
 
         let lines = [
-            "# Sub2API Status Bar Support Bundle",
+            strings.text(en: "# Sub2API Status Bar Support Bundle", zhHans: "# Sub2API Status Bar 支持包"),
             "",
-            "Review this bundle for secrets before posting it to a GitHub issue.",
+            strings.text(en: "Review this bundle for secrets before posting it to a GitHub issue.", zhHans: "发布到 GitHub issue 前，请检查此支持包是否包含敏感信息。"),
             "",
-            "Do not attach `config.json`, access tokens, refresh tokens, passwords, private server logs, full Application Support directories, release archives, or crash dumps that have not been reviewed for secrets.",
+            strings.text(en: "Do not attach `config.json`, access tokens, refresh tokens, passwords, private server logs, full Application Support directories, release archives, or crash dumps that have not been reviewed for secrets.", zhHans: "不要附加未经敏感信息检查的 `config.json`、访问令牌、刷新令牌、密码、私有服务器日志、完整 Application Support 目录、发布压缩包或崩溃转储。"),
             "",
-            "## Diagnostics",
+            strings.text(en: "## Diagnostics", zhHans: "## 诊断"),
             "",
             "```text",
             diagnostics,
             "```",
             "",
-            "## Environment",
+            strings.text(en: "## Environment", zhHans: "## 环境"),
             "",
-            "- App version: \(appVersion)",
-            "- macOS version: \(osVersion)",
-            "- Sub2API server version or commit, if known:",
-            "- Install source: \(installSource)",
-            "- Release asset name, if applicable:",
-            "- Release asset SHA-256 verification result, if applicable:",
+            strings.text(en: "- App version: \(appVersion)", zhHans: "- App 版本：\(appVersion)"),
+            strings.text(en: "- macOS version: \(osVersion)", zhHans: "- macOS 版本：\(osVersion)"),
+            strings.text(en: "- Sub2API server version or commit, if known:", zhHans: "- Sub2API 服务器版本或提交（如果知道）："),
+            strings.text(en: "- Install source: \(installSource)", zhHans: "- 安装来源：\(installSource)"),
+            strings.text(en: "- Release asset name, if applicable:", zhHans: "- 发布资产名称（如适用）："),
+            strings.text(en: "- Release asset SHA-256 verification result, if applicable:", zhHans: "- 发布资产 SHA-256 校验结果（如适用）："),
             "",
-            "## Reproduction",
+            strings.text(en: "## Reproduction", zhHans: "## 复现步骤"),
             "",
             "1.",
             "2.",
             "3.",
             "",
-            "## Expected Behavior",
+            strings.text(en: "## Expected Behavior", zhHans: "## 预期行为"),
             "",
-            "What did you expect to happen?",
+            strings.text(en: "What did you expect to happen?", zhHans: "你预期会发生什么？"),
             "",
-            "## Actual Behavior",
+            strings.text(en: "## Actual Behavior", zhHans: "## 实际行为"),
             "",
-            "What happened instead?",
+            strings.text(en: "What happened instead?", zhHans: "实际发生了什么？"),
             "",
-            "## Recent Changes",
+            strings.text(en: "## Recent Changes", zhHans: "## 最近变更"),
             "",
-            "- Did login, manual token setup, refresh, update checking, or installation work before?",
-            "- Did this begin after changing Sub2API server version, app version, account, network, or macOS settings?",
+            strings.text(en: "- Did login, manual token setup, refresh, update checking, or installation work before?", zhHans: "- 之前登录、手动令牌设置、刷新、更新检查或安装是否正常？"),
+            strings.text(en: "- Did this begin after changing Sub2API server version, app version, account, network, or macOS settings?", zhHans: "- 这是否发生在更改 Sub2API 服务器版本、App 版本、账户、网络或 macOS 设置之后？"),
             "",
-            "## Local Checks",
+            strings.text(en: "## Local Checks", zhHans: "## 本地检查"),
             "",
-            "- [ ] Diagnostics report contains token presence only, not token values.",
-            "- [ ] No `config.json` content is included.",
-            "- [ ] No access token, refresh token, password, private server URL, or private log is included.",
-            "- [ ] Release archive checksums were verified before reporting an installation issue.",
+            strings.text(en: "- [ ] Diagnostics report contains token presence only, not token values.", zhHans: "- [ ] 诊断报告只包含令牌是否存在，不包含令牌值。"),
+            strings.text(en: "- [ ] No `config.json` content is included.", zhHans: "- [ ] 未包含 `config.json` 内容。"),
+            strings.text(en: "- [ ] No access token, refresh token, password, private server URL, or private log is included.", zhHans: "- [ ] 未包含访问令牌、刷新令牌、密码、私有服务器 URL 或私有日志。"),
+            strings.text(en: "- [ ] Release archive checksums were verified before reporting an installation issue.", zhHans: "- [ ] 报告安装问题前已验证发布压缩包校验和。"),
         ]
 
         return lines.joined(separator: "\n")
diff --git a/Sources/Sub2APIStatusCore/UsageInsights.swift b/Sources/Sub2APIStatusCore/UsageInsights.swift
index 2ee8221..ed4aa95 100644
--- a/Sources/Sub2APIStatusCore/UsageInsights.swift
+++ b/Sources/Sub2APIStatusCore/UsageInsights.swift
@@ -68,37 +68,39 @@ public struct UsageInsights: Equatable, Sendable {
         subscriptionSummary: SubscriptionSummary?,
         trend: [TrendDataPoint]?,
         models: [ModelUsageSummary]?,
-        thresholds: InsightThresholds = .defaults
+        thresholds: InsightThresholds = .defaults,
+        language: AppLanguage = .en
     ) -> UsageInsights {
+        let strings = AppStrings(language: language)
         var thresholds = thresholds
         thresholds.normalize()
         var items: [UsageInsightItem] = []
 
-        if let quota = quotaInsight(subscriptionSummary, thresholds: thresholds) {
+        if let quota = quotaInsight(subscriptionSummary, thresholds: thresholds, strings: strings) {
             items.append(quota)
         }
 
-        if let balance = balanceInsight(currentUser: currentUser, stats: stats, thresholds: thresholds) {
+        if let balance = balanceInsight(currentUser: currentUser, stats: stats, thresholds: thresholds, strings: strings) {
             items.append(balance)
         }
 
-        if let budget = budgetInsight(stats: stats, trend: trend, thresholds: thresholds) {
+        if let budget = budgetInsight(stats: stats, trend: trend, thresholds: thresholds, strings: strings) {
             items.append(budget)
         }
 
-        if let spend = spendInsight(trend, thresholds: thresholds) {
+        if let spend = spendInsight(trend, thresholds: thresholds, strings: strings) {
             items.append(spend)
         }
 
-        if let trend = trendInsight(trend, thresholds: thresholds) {
+        if let trend = trendInsight(trend, thresholds: thresholds, strings: strings) {
             items.append(trend)
         }
 
-        if let modelMix = modelMixInsight(models, thresholds: thresholds) {
+        if let modelMix = modelMixInsight(models, thresholds: thresholds, strings: strings) {
             items.append(modelMix)
         }
 
-        if let performance = performanceInsight(stats, thresholds: thresholds) {
+        if let performance = performanceInsight(stats, thresholds: thresholds, strings: strings) {
             items.append(performance)
         }
 
@@ -109,20 +111,20 @@ public struct UsageInsights: Equatable, Sendable {
             return lhs.kind.sortRank < rhs.kind.sortRank
         }
 
-        let headline = items.first?.detail ?? "Usage is steady."
+        let headline = items.first?.detail ?? strings.text(en: "Usage is steady.", zhHans: "用量保持稳定。")
         return UsageInsights(headline: headline, items: Array(items.prefix(5)))
     }
 
-    private static func quotaInsight(_ summary: SubscriptionSummary?, thresholds: InsightThresholds) -> UsageInsightItem? {
+    private static func quotaInsight(_ summary: SubscriptionSummary?, thresholds: InsightThresholds, strings: AppStrings) -> UsageInsightItem? {
         guard let summary else {
             return nil
         }
 
         let candidates = summary.subscriptions.flatMap { item in
             [
-                (groupName: item.groupName, label: "daily", progress: item.dailyProgress, resetInSeconds: item.dailyResetInSeconds),
-                (groupName: item.groupName, label: "weekly", progress: item.weeklyProgress, resetInSeconds: item.weeklyResetInSeconds),
-                (groupName: item.groupName, label: "monthly", progress: item.monthlyProgress, resetInSeconds: item.monthlyResetInSeconds),
+                (groupName: item.groupName, label: strings.text(en: "daily", zhHans: "日"), progress: item.dailyProgress, resetInSeconds: item.dailyResetInSeconds),
+                (groupName: item.groupName, label: strings.text(en: "weekly", zhHans: "周"), progress: item.weeklyProgress, resetInSeconds: item.weeklyResetInSeconds),
+                (groupName: item.groupName, label: strings.text(en: "monthly", zhHans: "月"), progress: item.monthlyProgress, resetInSeconds: item.monthlyResetInSeconds),
             ]
         }
 
@@ -145,18 +147,18 @@ public struct UsageInsights: Equatable, Sendable {
             .healthy
         }
 
-        let title = "\(peak.groupName) \(peak.label) quota"
-        let resetText = peak.resetInSeconds.map { " and resets in \(StatusFormatters.duration(seconds: $0))" } ?? ""
+        let title = strings.text(en: "\(peak.groupName) \(peak.label) quota", zhHans: "\(peak.groupName)\(peak.label)配额")
+        let resetText = peak.resetInSeconds.map { strings.text(en: " and resets in \(StatusFormatters.duration(seconds: $0))", zhHans: "，将在 \(StatusFormatters.duration(seconds: $0)) 后重置") } ?? ""
         return UsageInsightItem(
             kind: .quota,
             severity: severity,
             title: title,
             value: StatusFormatters.percent(peak.progress),
-            detail: "\(title) is at \(StatusFormatters.percent(peak.progress))\(resetText)."
+            detail: strings.text(en: "\(title) is at \(StatusFormatters.percent(peak.progress))\(resetText).", zhHans: "\(title) 已达到 \(StatusFormatters.percent(peak.progress))\(resetText)。")
         )
     }
 
-    private static func balanceInsight(currentUser: CurrentUser?, stats: DashboardStats?, thresholds: InsightThresholds) -> UsageInsightItem? {
+    private static func balanceInsight(currentUser: CurrentUser?, stats: DashboardStats?, thresholds: InsightThresholds, strings: AppStrings) -> UsageInsightItem? {
         guard let balance = currentUser?.balance, balance > 0, let stats, stats.todayActualCost > 0 else {
             return nil
         }
@@ -173,13 +175,13 @@ public struct UsageInsights: Equatable, Sendable {
         return UsageInsightItem(
             kind: .balance,
             severity: severity,
-            title: "Balance runway",
+            title: strings.text(en: "Balance runway", zhHans: "余额续航"),
             value: String(format: "%.1fd", days),
-            detail: "Balance covers about \(String(format: "%.1f", days)) days at today's spend."
+            detail: strings.text(en: "Balance covers about \(String(format: "%.1f", days)) days at today's spend.", zhHans: "按今日花费计算，余额约可支撑 \(String(format: "%.1f", days)) 天。")
         )
     }
 
-    private static func budgetInsight(stats: DashboardStats?, trend: [TrendDataPoint]?, thresholds: InsightThresholds) -> UsageInsightItem? {
+    private static func budgetInsight(stats: DashboardStats?, trend: [TrendDataPoint]?, thresholds: InsightThresholds, strings: AppStrings) -> UsageInsightItem? {
         guard thresholds.monthlyBudgetUSD > 0 else {
             return nil
         }
@@ -208,13 +210,13 @@ public struct UsageInsights: Equatable, Sendable {
         return UsageInsightItem(
             kind: .budget,
             severity: severity,
-            title: "Monthly budget",
+            title: strings.text(en: "Monthly budget", zhHans: "月度预算"),
             value: StatusFormatters.currency(projectedSpend),
-            detail: "Projected monthly spend is \(StatusFormatters.currency(projectedSpend)) against a \(StatusFormatters.currency(budget)) budget."
+            detail: strings.text(en: "Projected monthly spend is \(StatusFormatters.currency(projectedSpend)) against a \(StatusFormatters.currency(budget)) budget.", zhHans: "预计月花费为 \(StatusFormatters.currency(projectedSpend))，预算为 \(StatusFormatters.currency(budget))。")
         )
     }
 
-    private static func trendInsight(_ trend: [TrendDataPoint]?, thresholds: InsightThresholds) -> UsageInsightItem? {
+    private static func trendInsight(_ trend: [TrendDataPoint]?, thresholds: InsightThresholds, strings: AppStrings) -> UsageInsightItem? {
         guard let trend, trend.count >= 4, let latest = trend.last else {
             return nil
         }
@@ -231,9 +233,9 @@ public struct UsageInsights: Equatable, Sendable {
             return UsageInsightItem(
                 kind: .trend,
                 severity: .healthy,
-                title: "Token trend",
-                value: "steady",
-                detail: "Token usage is close to the recent average."
+                title: strings.text(en: "Token trend", zhHans: "令牌趋势"),
+                value: strings.text(en: "steady", zhHans: "稳定"),
+                detail: strings.text(en: "Token usage is close to the recent average.", zhHans: "令牌用量接近近期平均水平。")
             )
         }
 
@@ -242,15 +244,15 @@ public struct UsageInsights: Equatable, Sendable {
         return UsageInsightItem(
             kind: .trend,
             severity: isSpike ? .warning : .healthy,
-            title: isSpike ? "Token surge" : "Token dip",
+            title: isSpike ? strings.text(en: "Token surge", zhHans: "令牌激增") : strings.text(en: "Token dip", zhHans: "令牌下降"),
             value: StatusFormatters.percent(change),
             detail: isSpike
-                ? "Today's tokens are \(StatusFormatters.percent(change)) above the recent average."
-                : "Today's tokens are \(StatusFormatters.percent(change)) below the recent average."
+                ? strings.text(en: "Today's tokens are \(StatusFormatters.percent(change)) above the recent average.", zhHans: "今日令牌比近期平均高 \(StatusFormatters.percent(change))。")
+                : strings.text(en: "Today's tokens are \(StatusFormatters.percent(change)) below the recent average.", zhHans: "今日令牌比近期平均低 \(StatusFormatters.percent(change))。")
         )
     }
 
-    private static func spendInsight(_ trend: [TrendDataPoint]?, thresholds: InsightThresholds) -> UsageInsightItem? {
+    private static func spendInsight(_ trend: [TrendDataPoint]?, thresholds: InsightThresholds, strings: AppStrings) -> UsageInsightItem? {
         guard let trend, trend.count >= 4, let latest = trend.last else {
             return nil
         }
@@ -270,13 +272,13 @@ public struct UsageInsights: Equatable, Sendable {
         return UsageInsightItem(
             kind: .spend,
             severity: .warning,
-            title: "Spend surge",
+            title: strings.text(en: "Spend surge", zhHans: "花费激增"),
             value: StatusFormatters.percent(change),
-            detail: "Today's spend is \(StatusFormatters.percent(change)) above the recent average."
+            detail: strings.text(en: "Today's spend is \(StatusFormatters.percent(change)) above the recent average.", zhHans: "今日花费比近期平均高 \(StatusFormatters.percent(change))。")
         )
     }
 
-    private static func modelMixInsight(_ models: [ModelUsageSummary]?, thresholds: InsightThresholds) -> UsageInsightItem? {
+    private static func modelMixInsight(_ models: [ModelUsageSummary]?, thresholds: InsightThresholds, strings: AppStrings) -> UsageInsightItem? {
         guard let models, models.count > 1 else {
             return nil
         }
@@ -291,13 +293,13 @@ public struct UsageInsights: Equatable, Sendable {
         return UsageInsightItem(
             kind: .modelMix,
             severity: severity,
-            title: "Top model",
+            title: strings.text(en: "Top model", zhHans: "主要模型"),
             value: StatusFormatters.percent(share),
-            detail: "\(top.model) drives \(StatusFormatters.percent(share)) of model spend."
+            detail: strings.text(en: "\(top.model) drives \(StatusFormatters.percent(share)) of model spend.", zhHans: "\(top.model) 占模型花费的 \(StatusFormatters.percent(share))。")
         )
     }
 
-    private static func performanceInsight(_ stats: DashboardStats?, thresholds: InsightThresholds) -> UsageInsightItem? {
+    private static func performanceInsight(_ stats: DashboardStats?, thresholds: InsightThresholds, strings: AppStrings) -> UsageInsightItem? {
         guard let stats else {
             return nil
         }
@@ -306,9 +308,9 @@ public struct UsageInsights: Equatable, Sendable {
             return UsageInsightItem(
                 kind: .performance,
                 severity: .warning,
-                title: "Latency",
+                title: strings.text(en: "Latency", zhHans: "延迟"),
                 value: String(format: "%.1fs", stats.averageDurationMs / 1_000),
-                detail: "Average response time is elevated."
+                detail: strings.text(en: "Average response time is elevated.", zhHans: "平均响应时间偏高。")
             )
         }
 
diff --git a/Sources/Sub2APIStatusCore/UsageReport.swift b/Sources/Sub2APIStatusCore/UsageReport.swift
index 20fc855..2b9e90e 100644
--- a/Sources/Sub2APIStatusCore/UsageReport.swift
+++ b/Sources/Sub2APIStatusCore/UsageReport.swift
@@ -4,51 +4,56 @@ public enum UsageReport {
     public static func make(
         config: AppConfig,
         snapshot: MonitorSnapshot,
-        now: Date = Date()
+        now: Date = Date(),
+        language: AppLanguage? = nil
     ) -> String {
+        let strings = AppStrings(language: language ?? .en)
         var lines = [
-            "Sub2API Usage Report",
-            "Generated: \(ISO8601DateFormatter().string(from: now))",
-            "Status: \(snapshot.statusLabel(now: now, refreshIntervalSeconds: config.refreshIntervalSeconds))",
-            "Account: \(accountText(snapshot.currentUser))",
+            strings.text(en: "Sub2API Usage Report", zhHans: "Sub2API 用量报告"),
+            "\(strings.generated): \(ISO8601DateFormatter().string(from: now))",
+            "\(strings.status): \(snapshot.statusLabel(now: now, refreshIntervalSeconds: config.refreshIntervalSeconds, language: language ?? .en))",
+            "\(strings.account): \(accountText(snapshot.currentUser, strings: strings))",
         ]
 
         if let lastUpdatedAt = snapshot.lastUpdatedAt {
-            lines.append("Last Updated: \(ISO8601DateFormatter().string(from: lastUpdatedAt))")
+            lines.append("\(strings.text(en: "Last Updated", zhHans: "上次更新")): \(ISO8601DateFormatter().string(from: lastUpdatedAt))")
         }
 
         if let balance = snapshot.currentUser?.balance {
-            lines.append("Balance: \(StatusFormatters.currency(balance))")
+            lines.append("\(strings.text(en: "Balance", zhHans: "余额")): \(StatusFormatters.currency(balance))")
         }
 
         if let stats = snapshot.stats {
-            lines.append("Today Spend: \(StatusFormatters.preciseCurrency(stats.todayActualCost))")
-            lines.append("Today Requests: \(StatusFormatters.menuBarCount(stats.todayRequests))")
-            lines.append("Today Tokens: \(StatusFormatters.compactNumber(stats.todayTokens))")
-            lines.append("Token Mix: \(tokenMix(stats))")
-            lines.append("Cost / MTok: \(StatusFormatters.costPerMillionTokens(cost: stats.todayActualCost, tokens: stats.todayTokens))")
-            lines.append("Throughput: \(StatusFormatters.menuBarRate(stats.rpm)) RPM / \(StatusFormatters.compactNumber(Int64(stats.tpm))) TPM")
-            lines.append("Average Response: \(latencyText(milliseconds: stats.averageDurationMs))")
-            lines.append("Lifetime Spend: \(StatusFormatters.preciseCurrency(stats.totalActualCost))")
-            lines.append("Lifetime Tokens: \(StatusFormatters.compactNumber(stats.totalTokens))")
+            lines.append("\(strings.text(en: "Today Spend", zhHans: "今日花费")): \(StatusFormatters.preciseCurrency(stats.todayActualCost))")
+            lines.append("\(strings.text(en: "Today Requests", zhHans: "今日请求")): \(StatusFormatters.menuBarCount(stats.todayRequests))")
+            lines.append("\(strings.text(en: "Today Tokens", zhHans: "今日令牌")): \(StatusFormatters.compactNumber(stats.todayTokens))")
+            lines.append("\(strings.text(en: "Token Mix", zhHans: "令牌构成")): \(tokenMix(stats, strings: strings))")
+            lines.append("\(strings.text(en: "Cost / MTok", zhHans: "每百万令牌成本")): \(StatusFormatters.costPerMillionTokens(cost: stats.todayActualCost, tokens: stats.todayTokens))")
+            lines.append("\(strings.text(en: "Throughput", zhHans: "吞吐量")): \(StatusFormatters.menuBarRate(stats.rpm)) RPM / \(StatusFormatters.compactNumber(Int64(stats.tpm))) TPM")
+            lines.append("\(strings.averageResponse): \(latencyText(milliseconds: stats.averageDurationMs))")
+            lines.append("\(strings.text(en: "Lifetime Spend", zhHans: "累计花费")): \(StatusFormatters.preciseCurrency(stats.totalActualCost))")
+            lines.append("\(strings.text(en: "Lifetime Tokens", zhHans: "累计令牌")): \(StatusFormatters.compactNumber(stats.totalTokens))")
         }
 
         if let subscriptionSummary = snapshot.subscriptionSummary {
-            lines.append("Subscriptions: \(subscriptionSummary.activeCount) active")
-            if let quota = topQuota(subscriptionSummary) {
-                let resetText = quota.resetInSeconds.map { ", resets in \(StatusFormatters.duration(seconds: $0))" } ?? ""
+            lines.append(strings.text(en: "Subscriptions: \(subscriptionSummary.activeCount) active", zhHans: "订阅：\(subscriptionSummary.activeCount) 个活跃"))
+            if let quota = topQuota(subscriptionSummary, strings: strings) {
+                let resetText = quota.resetInSeconds.map { strings.text(en: ", resets in \(StatusFormatters.duration(seconds: $0))", zhHans: "，\(StatusFormatters.duration(seconds: $0)) 后重置") } ?? ""
                 lines.append("\(quota.name): \(StatusFormatters.percent(quota.progress))\(resetText)")
             }
         }
 
         if let latestTrend = snapshot.trend?.last {
             lines.append(
-                "Trend \(latestTrend.date): \(StatusFormatters.menuBarCount(latestTrend.requests)) requests, \(StatusFormatters.compactNumber(latestTrend.totalTokens)) tokens, \(StatusFormatters.preciseCurrency(latestTrend.actualCost))"
+                strings.text(
+                    en: "Trend \(latestTrend.date): \(StatusFormatters.menuBarCount(latestTrend.requests)) requests, \(StatusFormatters.compactNumber(latestTrend.totalTokens)) tokens, \(StatusFormatters.preciseCurrency(latestTrend.actualCost))",
+                    zhHans: "趋势 \(latestTrend.date)：\(StatusFormatters.menuBarCount(latestTrend.requests)) 次请求，\(StatusFormatters.compactNumber(latestTrend.totalTokens)) 令牌，\(StatusFormatters.preciseCurrency(latestTrend.actualCost))"
+                )
             )
         }
 
-        if let modelText = topModelsText(snapshot.modelDistribution) {
-            lines.append("Top Models: \(modelText)")
+        if let modelText = topModelsText(snapshot.modelDistribution, strings: strings) {
+            lines.append("\(strings.text(en: "Top Models", zhHans: "主要模型")): \(modelText)")
         }
 
         if snapshot.connected {
@@ -58,24 +63,25 @@ public enum UsageReport {
                 subscriptionSummary: snapshot.subscriptionSummary,
                 trend: snapshot.trend,
                 models: snapshot.modelDistribution,
-                thresholds: config.insightThresholds
+                thresholds: config.insightThresholds,
+                language: language ?? .en
             )
-            lines.append("Insight: \(insights.headline)")
+            lines.append("\(strings.text(en: "Insight", zhHans: "洞察")): \(insights.headline)")
             for item in insights.items {
                 lines.append("- \(item.title): \(item.value) - \(item.detail)")
             }
         }
 
         if let message = snapshot.message, !message.isEmpty {
-            lines.append("Message: \(message)")
+            lines.append("\(strings.text(en: "Message", zhHans: "消息")): \(message)")
         }
 
         return lines.joined(separator: "\n")
     }
 
-    private static func accountText(_ user: CurrentUser?) -> String {
+    private static func accountText(_ user: CurrentUser?, strings: AppStrings) -> String {
         guard let user else {
-            return "Unknown"
+            return strings.text(en: "Unknown", zhHans: "未知")
         }
 
         let displayName = if let username = user.username, !username.isEmpty {
@@ -90,11 +96,11 @@ public enum UsageReport {
         return "\(displayName) <\(user.email)>"
     }
 
-    private static func tokenMix(_ stats: DashboardStats) -> String {
+    private static func tokenMix(_ stats: DashboardStats, strings: AppStrings) -> String {
         [
-            "Input \(StatusFormatters.compactNumber(stats.todayInputTokens))",
-            "Output \(StatusFormatters.compactNumber(stats.todayOutputTokens))",
-            "Cache Read \(StatusFormatters.compactNumber(stats.todayCacheReadTokens))",
+            strings.text(en: "Input \(StatusFormatters.compactNumber(stats.todayInputTokens))", zhHans: "输入 \(StatusFormatters.compactNumber(stats.todayInputTokens))"),
+            strings.text(en: "Output \(StatusFormatters.compactNumber(stats.todayOutputTokens))", zhHans: "输出 \(StatusFormatters.compactNumber(stats.todayOutputTokens))"),
+            strings.text(en: "Cache Read \(StatusFormatters.compactNumber(stats.todayCacheReadTokens))", zhHans: "缓存读取 \(StatusFormatters.compactNumber(stats.todayCacheReadTokens))"),
         ].joined(separator: " / ")
     }
 
@@ -105,13 +111,13 @@ public enum UsageReport {
         return "\(Int(milliseconds))ms"
     }
 
-    private static func topQuota(_ summary: SubscriptionSummary) -> (name: String, progress: Double, resetInSeconds: Double?)? {
+    private static func topQuota(_ summary: SubscriptionSummary, strings: AppStrings) -> (name: String, progress: Double, resetInSeconds: Double?)? {
         summary.subscriptions
             .flatMap { item in
                 [
-                    (name: "\(item.groupName) daily quota", progress: item.dailyProgress, resetInSeconds: item.dailyResetInSeconds),
-                    (name: "\(item.groupName) weekly quota", progress: item.weeklyProgress, resetInSeconds: item.weeklyResetInSeconds),
-                    (name: "\(item.groupName) monthly quota", progress: item.monthlyProgress, resetInSeconds: item.monthlyResetInSeconds),
+                    (name: strings.text(en: "\(item.groupName) daily quota", zhHans: "\(item.groupName) 日配额"), progress: item.dailyProgress, resetInSeconds: item.dailyResetInSeconds),
+                    (name: strings.text(en: "\(item.groupName) weekly quota", zhHans: "\(item.groupName) 周配额"), progress: item.weeklyProgress, resetInSeconds: item.weeklyResetInSeconds),
+                    (name: strings.text(en: "\(item.groupName) monthly quota", zhHans: "\(item.groupName) 月配额"), progress: item.monthlyProgress, resetInSeconds: item.monthlyResetInSeconds),
                 ]
             }
             .compactMap { candidate -> (name: String, progress: Double, resetInSeconds: Double?)? in
@@ -123,14 +129,14 @@ public enum UsageReport {
             .max(by: { $0.progress < $1.progress })
     }
 
-    private static func topModelsText(_ models: [ModelUsageSummary]?) -> String? {
+    private static func topModelsText(_ models: [ModelUsageSummary]?, strings: AppStrings) -> String? {
         guard let models, !models.isEmpty else {
             return nil
         }
 
         return models
             .prefix(3)
-            .map { "\($0.model) \(StatusFormatters.preciseCurrency($0.actualCost)) (\(StatusFormatters.compactNumber($0.totalTokens)) tokens)" }
+            .map { strings.text(en: "\($0.model) \(StatusFormatters.preciseCurrency($0.actualCost)) (\(StatusFormatters.compactNumber($0.totalTokens)) tokens)", zhHans: "\($0.model) \(StatusFormatters.preciseCurrency($0.actualCost))（\(StatusFormatters.compactNumber($0.totalTokens)) 令牌）") }
             .joined(separator: ", ")
     }
 }
diff --git a/Tests/Sub2APIStatusCoreTests/Sub2APIStatusCoreTests.swift b/Tests/Sub2APIStatusCoreTests/Sub2APIStatusCoreTests.swift
index 49e9709..92033cd 100644
--- a/Tests/Sub2APIStatusCoreTests/Sub2APIStatusCoreTests.swift
+++ b/Tests/Sub2APIStatusCoreTests/Sub2APIStatusCoreTests.swift
@@ -1558,6 +1558,77 @@ private func pngSize(_ data: Data) -> (width: Int, height: Int)? {
     #expect(summary.shareText.contains("Das") == false)
 }
 
+@Test func generatedReportsCanRenderSimplifiedChineseWithoutSecrets() {
+    let config = AppConfig(
+        baseURL: "https://sub2api.example.com",
+        authToken: "secret-access-token",
+        refreshToken: "secret-refresh-token",
+        refreshIntervalSeconds: 30,
+        language: .zhHans
+    )
+    let snapshot = MonitorSnapshot(
+        mode: .user,
+        connected: true,
+        currentUser: CurrentUser(id: 1, email: "das@example.com", username: "Das", role: "user", balance: 300, status: "active"),
+        stats: DashboardStats(todayRequests: 42, todayTokens: 123_456, todayInputTokens: 1_000, todayOutputTokens: 2_000, todayCacheReadTokens: 3_000, todayActualCost: 3.14, rpm: 2, tpm: 100),
+        trend: nil,
+        modelDistribution: nil,
+        realtime: nil,
+        accountHealth: nil,
+        subscriptionSummary: nil,
+        lastUpdatedAt: Date(timeIntervalSince1970: 1_000),
+        message: nil
+    )
+
+    let usage = UsageReport.make(config: config, snapshot: snapshot, now: Date(timeIntervalSince1970: 1_060), language: .zhHans)
+    let diagnostics = DiagnosticReport.make(config: config, snapshot: snapshot, appVersion: "0.1.11", osVersion: "macOS 15.0", language: .zhHans)
+    let support = SupportBundleReport.make(config: config, snapshot: snapshot, appVersion: "0.1.11", osVersion: "macOS 15.0", language: .zhHans)
+    let share = SocialShareSummary.make(config: config, snapshot: snapshot, now: Date(timeIntervalSince1970: 1_060), language: .zhHans)
+
+    #expect(usage.contains("Sub2API 用量报告"))
+    #expect(usage.contains("状态"))
+    #expect(usage.contains("账户"))
+    #expect(diagnostics.contains("Sub2API Status Bar 诊断"))
+    #expect(diagnostics.contains("访问令牌: 存在") || diagnostics.contains("访问令牌：存在"))
+    #expect(support.contains("Sub2API Status Bar 支持包"))
+    #expect(support.contains("诊断报告只包含令牌是否存在"))
+    #expect(share.title.contains("AI 令牌"))
+    #expect(share.shareText.contains("不含提示词。不含密钥。"))
+
+    for output in [usage, diagnostics, support, share.shareText] {
+        #expect(output.contains("secret-access-token") == false)
+        #expect(output.contains("secret-refresh-token") == false)
+    }
+}
+
+@Test func recoveryChecklistAndInsightAlertsCanRenderSimplifiedChinese() {
+    let recovery = RecoverySuggestion.make(message: "401 unauthorized", hasBaseURL: true, hasToken: true, language: .zhHans)
+    let checklist = OnboardingChecklist.make(
+        form: LoginFormState(baseURL: "", email: "", password: ""),
+        manualToken: "",
+        language: .zhHans
+    )
+    let alert = InsightAlertPolicy(settings: .defaults).staleDataAlert(
+        from: MonitorSnapshot(
+            mode: .user,
+            connected: true,
+            stats: DashboardStats(todayRequests: 1),
+            lastUpdatedAt: Date(timeIntervalSince1970: 0),
+            message: nil
+        ),
+        refreshIntervalSeconds: 5,
+        lastAlertedAtByFingerprint: [:],
+        now: Date(timeIntervalSince1970: 30),
+        language: .zhHans
+    )
+
+    #expect(recovery.title == "重新登录")
+    #expect(checklist.steps.map(\.title) == ["服务器 URL", "账户", "密码或令牌"])
+    #expect(checklist.summary.contains("请补充"))
+    #expect(alert?.title == "数据已过期")
+    #expect(alert?.body.contains("未刷新") == true)
+}
+
 @Test func loginFormStateRequiresURLAccountAndPassword() {
     #expect(LoginFormState(baseURL: "", email: "a@example.com", password: "secret").canSubmit == false)
     #expect(LoginFormState(baseURL: "http://127.0.0.1:8080", email: "", password: "secret").canSubmit == false)

From a6515da06c03c2d03bed0f624816d9609c7ba6d6 Mon Sep 17 00:00:00 2001
From: maple <maple@MacBook-Air.local>
Date: Tue, 2 Jun 2026 21:08:08 +0800
Subject: [PATCH 5/6] feat: add runtime language setting

---
 Sources/Sub2APIStatusBar/ChartViews.swift     |  6 +-
 .../DashboardComponents.swift                 |  8 +-
 Sources/Sub2APIStatusBar/LoginViews.swift     | 33 ++++---
 Sources/Sub2APIStatusBar/MonitorPanel.swift   | 58 ++++++-----
 .../Sub2APIStatusBar/MonitorViewModel.swift   | 10 +-
 Sources/Sub2APIStatusBar/QuotaViews.swift     | 20 ++--
 Sources/Sub2APIStatusBar/SettingsView.swift   | 96 +++++++++++--------
 .../Sub2APIStatusBarApp.swift                 |  9 +-
 8 files changed, 142 insertions(+), 98 deletions(-)

diff --git a/Sources/Sub2APIStatusBar/ChartViews.swift b/Sources/Sub2APIStatusBar/ChartViews.swift
index 0185df2..d7e36fd 100644
--- a/Sources/Sub2APIStatusBar/ChartViews.swift
+++ b/Sources/Sub2APIStatusBar/ChartViews.swift
@@ -3,13 +3,16 @@ import Sub2APIStatusCore
 
 struct ModelDistributionView: View {
     let models: [ModelUsageSummary]
+    var language: AppLanguage = .en
+
+    private var strings: AppStrings { AppStrings(language: language) }
 
     private var visibleModels: [ModelUsageDisplay] {
         ModelUsageDisplay.make(models)
     }
 
     var body: some View {
-        SectionBlock(title: "Model Distribution") {
+        SectionBlock(title: strings.text(en: "Model Distribution", zhHans: "模型分布")) {
             VStack(spacing: 0) {
                 ForEach(visibleModels) { item in
                     VStack(spacing: 8) {
@@ -55,6 +58,7 @@ struct ModelDistributionView: View {
 
 struct UsageTrendSection: View {
     let state: UsageTrendDisplayState
+    var language: AppLanguage = .en
     @State private var selectedMode: UsageTrendMode = .tokens
 
     var body: some View {
diff --git a/Sources/Sub2APIStatusBar/DashboardComponents.swift b/Sources/Sub2APIStatusBar/DashboardComponents.swift
index 2cacddd..c179f9f 100644
--- a/Sources/Sub2APIStatusBar/DashboardComponents.swift
+++ b/Sources/Sub2APIStatusBar/DashboardComponents.swift
@@ -21,6 +21,7 @@ struct MetricItem: Identifiable {
 
 struct UserAccountCard: View {
     let user: CurrentUser
+    var language: AppLanguage = .en
 
     private var displayName: String {
         guard let username = user.username, !username.isEmpty else {
@@ -52,7 +53,7 @@ struct UserAccountCard: View {
 
             if let status = user.status, !status.isEmpty {
                 StatusPill(
-                    text: status.capitalized,
+                    text: status.lowercased() == "active" ? AppStrings(language: language).text(en: "Active", zhHans: "活跃") : status.capitalized,
                     color: status.lowercased() == "active" ? .green : .secondary
                 )
             }
@@ -127,11 +128,14 @@ private struct SafeSystemImage: View {
 
 struct UsageInsightsView: View {
     let insights: UsageInsights
+    var language: AppLanguage = .en
+
+    private var strings: AppStrings { AppStrings(language: language) }
 
     var body: some View {
         VStack(alignment: .leading, spacing: 10) {
             HStack(alignment: .firstTextBaseline) {
-                Label("Usage Insights", systemImage: "sparkles")
+                Label(strings.usageInsights, systemImage: "sparkles")
                     .font(.system(size: 14, weight: .semibold))
                 Spacer()
                 Text(insights.headline)
diff --git a/Sources/Sub2APIStatusBar/LoginViews.swift b/Sources/Sub2APIStatusBar/LoginViews.swift
index 684dffc..b170148 100644
--- a/Sources/Sub2APIStatusBar/LoginViews.swift
+++ b/Sources/Sub2APIStatusBar/LoginViews.swift
@@ -5,6 +5,8 @@ struct LoginPanel: View {
     @ObservedObject var model: MonitorViewModel
     @FocusState private var focusedField: FocusedLoginField?
 
+    private var strings: AppStrings { AppStrings(language: model.settingsDraft.language) }
+
     private var formState: LoginFormState {
         LoginFormState(
             baseURL: model.settingsDraft.baseURL,
@@ -23,7 +25,7 @@ struct LoginPanel: View {
                 VStack(alignment: .leading, spacing: 3) {
                     Text("Sub2API")
                         .font(.title2.bold())
-                    Text("Connect your server")
+                    Text(strings.connectYourServer)
                         .font(.callout)
                         .foregroundStyle(.secondary)
                 }
@@ -33,23 +35,23 @@ struct LoginPanel: View {
                 AccountListSection(model: model)
             }
 
-            OnboardingChecklistView(checklist: checklist)
+            OnboardingChecklistView(checklist: checklist, language: model.settingsDraft.language)
 
             VStack(alignment: .leading, spacing: 12) {
-                TextField("Server URL", text: $model.settingsDraft.baseURL)
+                TextField(strings.serverURL, text: $model.settingsDraft.baseURL)
                     .textFieldStyle(.roundedBorder)
                     .focused($focusedField, equals: .serverURL)
 
-                TextField("Account", text: $model.loginEmail)
+                TextField(strings.account, text: $model.loginEmail)
                     .textFieldStyle(.roundedBorder)
                     .focused($focusedField, equals: .email)
 
-                SecureField("Password", text: $model.loginPassword)
+                SecureField(strings.text(en: "Password", zhHans: "密码"), text: $model.loginPassword)
                     .textFieldStyle(.roundedBorder)
                     .focused($focusedField, equals: .password)
 
                 HStack {
-                    Text("Refresh")
+                    Text(strings.refresh)
                         .font(.callout)
                         .foregroundStyle(.secondary)
                     Slider(value: $model.settingsDraft.refreshIntervalSeconds, in: 5...300, step: 5)
@@ -77,7 +79,7 @@ struct LoginPanel: View {
                     } else {
                         Image(systemName: "key.fill")
                     }
-                    Text(model.isLoggingIn ? "Connecting..." : "Login")
+                    Text(model.isLoggingIn ? strings.connecting : strings.login)
                 }
                 .frame(maxWidth: .infinity)
             }
@@ -88,9 +90,9 @@ struct LoginPanel: View {
             Divider()
 
             VStack(alignment: .leading, spacing: 8) {
-                Text("Manual token")
+                Text(strings.manualToken)
                     .font(.headline)
-                SecureField("Bearer Token", text: $model.settingsDraft.authToken)
+                SecureField(strings.bearerToken, text: $model.settingsDraft.authToken)
                     .textFieldStyle(.roundedBorder)
                     .focused($focusedField, equals: .token)
                 Button {
@@ -102,7 +104,7 @@ struct LoginPanel: View {
                     )
                     model.saveSettings()
                 } label: {
-                    Label("Save Token", systemImage: "square.and.arrow.down")
+                    Label(strings.saveToken, systemImage: "square.and.arrow.down")
                 }
                 .disabled(model.settingsDraft.authToken.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty)
             }
@@ -113,7 +115,7 @@ struct LoginPanel: View {
                 Button {
                     model.openURL(model.settingsDraft.baseURL)
                 } label: {
-                    Label("Open Server", systemImage: "safari")
+                    Label(strings.openServer, systemImage: "safari")
                 }
                 .disabled(model.settingsDraft.baseURL.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty)
 
@@ -122,7 +124,7 @@ struct LoginPanel: View {
                 Button {
                     model.quit()
                 } label: {
-                    Label("Quit", systemImage: "power")
+                    Label(strings.quit, systemImage: "power")
                 }
             }
             .buttonStyle(.borderless)
@@ -161,11 +163,14 @@ struct LoginPanel: View {
 
 struct OnboardingChecklistView: View {
     let checklist: OnboardingChecklist
+    var language: AppLanguage = .en
+
+    private var strings: AppStrings { AppStrings(language: language) }
 
     var body: some View {
         VStack(alignment: .leading, spacing: 9) {
             HStack {
-                Text("Connection Checklist")
+                Text(strings.connectionChecklist)
                     .font(.headline)
                 Spacer()
                 Text(checklist.summary)
@@ -211,7 +216,7 @@ struct AccountListSection: View {
 
     var body: some View {
         VStack(alignment: .leading, spacing: 8) {
-            Text("Accounts")
+            Text(AppStrings(language: model.settingsDraft.language).accounts)
                 .font(.headline)
 
             ForEach(model.config.accounts) { account in
diff --git a/Sources/Sub2APIStatusBar/MonitorPanel.swift b/Sources/Sub2APIStatusBar/MonitorPanel.swift
index 922641c..b56ec26 100644
--- a/Sources/Sub2APIStatusBar/MonitorPanel.swift
+++ b/Sources/Sub2APIStatusBar/MonitorPanel.swift
@@ -3,6 +3,8 @@ import Sub2APIStatusCore
 
 struct MonitorPanel: View {
     @ObservedObject var model: MonitorViewModel
+
+    private var strings: AppStrings { AppStrings(language: model.config.language) }
     @State private var showingSettings = false
 
     var body: some View {
@@ -28,18 +30,19 @@ struct MonitorPanel: View {
                                         stats: model.snapshot.stats,
                                         balanceText: balanceText,
                                         quotaText: quotaHeadline,
+                                        language: model.config.language,
                                         tokenBreakdown: tokenBreakdown
                                     )
 
                                     shareToolbar
 
                                     SectionBlock(title: "Usage Trend") {
-                                        UsageTrendSection(state: UsageTrendDisplayState.make(points: model.snapshot.trend))
+                                        UsageTrendSection(state: UsageTrendDisplayState.make(points: model.snapshot.trend), language: model.config.language)
                                     }
                                 }
 
                                 if let updateInfo = model.updateInfo, updateInfo.isUpdateAvailable {
-                                    UpdateAvailableBanner(info: updateInfo) {
+                                    UpdateAvailableBanner(info: updateInfo, language: model.config.language) {
                                         model.openLatestRelease()
                                     }
                                 }
@@ -84,7 +87,7 @@ struct MonitorPanel: View {
                 Text(activeAccountTitle)
                     .font(.system(size: 15, weight: .semibold))
                     .lineLimit(1)
-                Text(model.snapshot.connected ? lastUpdatedText : "Disconnected")
+                Text(model.snapshot.connected ? lastUpdatedText : strings.disconnected)
                     .font(.caption)
                     .foregroundStyle(.secondary)
             }
@@ -101,7 +104,7 @@ struct MonitorPanel: View {
                 Image(systemName: model.isRefreshing ? "arrow.triangle.2.circlepath" : "arrow.clockwise")
             }
             .disabled(model.isRefreshing)
-            .help("Refresh")
+            .help(strings.refresh)
 
             Button {
                 model.settingsDraft = model.config
@@ -109,7 +112,7 @@ struct MonitorPanel: View {
             } label: {
                 Image(systemName: "gearshape")
             }
-            .help("Settings")
+            .help(strings.settings)
         }
         .buttonStyle(.borderless)
         .padding(.horizontal, 18)
@@ -125,11 +128,11 @@ struct MonitorPanel: View {
     private var statusSection: some View {
         VStack(alignment: .leading, spacing: 12) {
             if model.config.authToken.isEmpty {
-                Text("Set Base URL and token to start monitoring.")
+                Text(strings.setBaseURLAndToken)
                     .font(.callout)
                     .foregroundStyle(.secondary)
             } else if model.snapshot.connected {
-                UsageInsightsView(insights: usageInsights)
+                UsageInsightsView(insights: usageInsights, language: model.config.language)
             }
         }
     }
@@ -140,19 +143,19 @@ struct MonitorPanel: View {
                 Button {
                     model.copySocialShareCard()
                 } label: {
-                    Label("Share Card", systemImage: "square.and.arrow.up")
+                    Label(strings.shareCard, systemImage: "square.and.arrow.up")
                 }
 
                 Button {
                     model.copyUsageReport()
                 } label: {
-                    Label("Report", systemImage: "doc.on.doc")
+                    Label(strings.report, systemImage: "doc.on.doc")
                 }
 
                 Button {
                     model.openSocialShareDraft()
                 } label: {
-                    Label("Post", systemImage: "paperplane")
+                    Label(strings.post, systemImage: "paperplane")
                 }
 
                 Spacer()
@@ -176,11 +179,11 @@ struct MonitorPanel: View {
     private var userSection: some View {
         VStack(alignment: .leading, spacing: 14) {
             if let user = model.snapshot.currentUser {
-                UserAccountCard(user: user)
+                UserAccountCard(user: user, language: model.config.language)
             }
 
             if let stats = model.snapshot.stats {
-                Text("Details")
+                Text(strings.details)
                     .font(.system(size: 14, weight: .semibold))
                     .foregroundStyle(.primary)
                 MetricGrid(items: [
@@ -209,14 +212,14 @@ struct MonitorPanel: View {
                 SectionBlock(title: "Subscriptions") {
                     VStack(spacing: 10) {
                         ForEach(summary.subscriptions.prefix(5)) { item in
-                            SubscriptionQuotaCard(item: item)
+                            SubscriptionQuotaCard(item: item, language: model.config.language)
                         }
                     }
                 }
             }
 
             if let models = model.snapshot.modelDistribution, !models.isEmpty {
-                ModelDistributionView(models: models)
+                ModelDistributionView(models: models, language: model.config.language)
             }
         }
     }
@@ -226,7 +229,7 @@ struct MonitorPanel: View {
             Button {
                 model.openDashboard()
             } label: {
-                Label("Open", systemImage: "safari")
+                Label(strings.open, systemImage: "safari")
             }
             .disabled(model.config.baseURL.isEmpty)
 
@@ -235,7 +238,7 @@ struct MonitorPanel: View {
             Button {
                 model.quit()
             } label: {
-                Label("Quit", systemImage: "power")
+                Label(strings.quit, systemImage: "power")
             }
         }
         .buttonStyle(.borderless)
@@ -287,10 +290,10 @@ struct MonitorPanel: View {
 
     private var quotaHeadline: String {
         guard let summary = model.snapshot.subscriptionSummary else {
-            return "No quota data"
+            return strings.text(en: "No quota data", zhHans: "暂无配额数据")
         }
         let progress = StatusFormatters.percent(summary.highestProgress)
-        return "\(progress) peak"
+        return strings.text(en: "\(progress) peak", zhHans: "峰值 \(progress)")
     }
 
     private var usageInsights: UsageInsights {
@@ -346,7 +349,7 @@ struct AccountSwitcher: View {
             Image(systemName: "person.2")
         }
         .menuStyle(.borderlessButton)
-        .help("Switch account")
+        .help(AppStrings(language: model.config.language).text(en: "Switch account", zhHans: "切换账户"))
     }
 }
 
@@ -356,14 +359,17 @@ struct OverviewCard: View {
     let stats: DashboardStats?
     let balanceText: String
     let quotaText: String
+    let language: AppLanguage
     let tokenBreakdown: (Int64, Int64) -> String
 
+    private var strings: AppStrings { AppStrings(language: language) }
+
     var body: some View {
         VStack(alignment: .leading, spacing: 18) {
             HStack(alignment: .top) {
                 VStack(alignment: .leading, spacing: 4) {
                     StatusPill(text: statusText, color: statusColor, systemImage: "circle.fill")
-                    Text("Today")
+                    Text(strings.today)
                         .font(.system(size: 12, weight: .medium))
                         .foregroundStyle(.secondary)
                 }
@@ -373,7 +379,7 @@ struct OverviewCard: View {
                 VStack(alignment: .trailing, spacing: 2) {
                     Text(balanceText)
                         .font(.system(size: 17, weight: .bold, design: .rounded).monospacedDigit())
-                    Text("balance")
+                    Text(strings.balance)
                         .font(.caption2)
                         .foregroundStyle(.secondary)
                 }
@@ -386,15 +392,15 @@ struct OverviewCard: View {
                         .foregroundStyle(.primary)
                         .lineLimit(1)
                         .minimumScaleFactor(0.68)
-                    Text("tokens")
+                    Text(strings.tokens)
                         .font(.system(size: 16, weight: .semibold, design: .rounded))
                         .foregroundStyle(.secondary)
                 }
 
                 HStack(spacing: 10) {
-                    OverviewStat(title: "Spend", value: StatusFormatters.preciseCurrency(stats.todayActualCost), color: .green)
-                    OverviewStat(title: "Requests", value: StatusFormatters.menuBarCount(stats.todayRequests), color: .blue)
-                    OverviewStat(title: "Quota", value: quotaText, color: .orange)
+                    OverviewStat(title: strings.text(en: "Spend", zhHans: "花费"), value: StatusFormatters.preciseCurrency(stats.todayActualCost), color: .green)
+                    OverviewStat(title: strings.text(en: "Requests", zhHans: "请求"), value: StatusFormatters.menuBarCount(stats.todayRequests), color: .blue)
+                    OverviewStat(title: strings.text(en: "Quota", zhHans: "配额"), value: quotaText, color: .orange)
                 }
 
                 Text(tokenBreakdown(stats.todayInputTokens, stats.todayOutputTokens))
@@ -402,7 +408,7 @@ struct OverviewCard: View {
                     .foregroundStyle(.secondary)
                     .lineLimit(1)
             } else {
-                Text("Waiting for usage data.")
+                Text(strings.waitingForUsageData)
                     .font(.callout)
                     .foregroundStyle(.secondary)
             }
diff --git a/Sources/Sub2APIStatusBar/MonitorViewModel.swift b/Sources/Sub2APIStatusBar/MonitorViewModel.swift
index 416e74c..b78c5a8 100644
--- a/Sources/Sub2APIStatusBar/MonitorViewModel.swift
+++ b/Sources/Sub2APIStatusBar/MonitorViewModel.swift
@@ -320,7 +320,7 @@ final class MonitorViewModel: ObservableObject {
         )
         NSPasteboard.general.clearContents()
         NSPasteboard.general.setString(report, forType: .string)
-        updateStatusMessage = "Diagnostics copied."
+        updateStatusMessage = AppStrings(language: config.language).text(en: "Diagnostics copied.", zhHans: "诊断已复制。")
     }
 
     func copySupportBundle() {
@@ -332,7 +332,7 @@ final class MonitorViewModel: ObservableObject {
         )
         NSPasteboard.general.clearContents()
         NSPasteboard.general.setString(report, forType: .string)
-        updateStatusMessage = "Support bundle copied."
+        updateStatusMessage = AppStrings(language: config.language).text(en: "Support bundle copied.", zhHans: "支持包已复制。")
     }
 
     func copyUsageReport() {
@@ -344,7 +344,7 @@ final class MonitorViewModel: ObservableObject {
         )
         NSPasteboard.general.clearContents()
         NSPasteboard.general.setString(report, forType: .string)
-        updateStatusMessage = "Usage report copied."
+        updateStatusMessage = AppStrings(language: config.language).text(en: "Usage report copied.", zhHans: "用量报告已复制。")
     }
 
     func copySocialShareCard() {
@@ -358,10 +358,10 @@ final class MonitorViewModel: ObservableObject {
         pasteboard.clearContents()
         if let image = SocialShareCardRenderer.image(for: summary) {
             pasteboard.writeObjects([image, NSString(string: summary.shareText)])
-            updateStatusMessage = "Share card copied."
+            updateStatusMessage = AppStrings(language: config.language).text(en: "Share card copied.", zhHans: "分享卡片已复制。")
         } else {
             pasteboard.setString(summary.shareText, forType: .string)
-            updateStatusMessage = "Share text copied."
+            updateStatusMessage = AppStrings(language: config.language).text(en: "Share text copied.", zhHans: "分享文本已复制。")
         }
     }
 
diff --git a/Sources/Sub2APIStatusBar/QuotaViews.swift b/Sources/Sub2APIStatusBar/QuotaViews.swift
index bd6c17d..f59d682 100644
--- a/Sources/Sub2APIStatusBar/QuotaViews.swift
+++ b/Sources/Sub2APIStatusBar/QuotaViews.swift
@@ -3,6 +3,9 @@ import Sub2APIStatusCore
 
 struct SubscriptionQuotaCard: View {
     let item: SubscriptionSummaryItem
+    var language: AppLanguage = .en
+
+    private var strings: AppStrings { AppStrings(language: language) }
 
     var body: some View {
         VStack(alignment: .leading, spacing: 12) {
@@ -14,7 +17,7 @@ struct SubscriptionQuotaCard: View {
                     .font(.callout.weight(.semibold))
                 Spacer()
                 StatusPill(
-                    text: item.status == "active" ? "Active" : item.status,
+                    text: item.status == "active" ? strings.text(en: "Active", zhHans: "活跃") : item.status,
                     color: item.status == "active" ? .green : .secondary
                 )
             }
@@ -22,7 +25,7 @@ struct SubscriptionQuotaCard: View {
             quotaSummary
 
             ForEach(quotaWindows, id: \.title) { window in
-                QuotaProgressRow(window: window)
+                QuotaProgressRow(window: window, language: language)
             }
         }
     }
@@ -30,21 +33,21 @@ struct SubscriptionQuotaCard: View {
     private var quotaWindows: [QuotaWindowDisplay] {
         [
             QuotaWindowDisplay(
-                title: "Daily",
+                title: strings.text(en: "Daily", zhHans: "每日"),
                 used: item.dailyUsedUSD,
                 limit: item.dailyLimitUSD,
                 progress: item.dailyProgress,
                 resetInSeconds: item.dailyResetInSeconds
             ),
             QuotaWindowDisplay(
-                title: "Weekly",
+                title: strings.text(en: "Weekly", zhHans: "每周"),
                 used: item.weeklyUsedUSD,
                 limit: item.weeklyLimitUSD,
                 progress: item.weeklyProgress,
                 resetInSeconds: item.weeklyResetInSeconds
             ),
             QuotaWindowDisplay(
-                title: "Monthly",
+                title: strings.text(en: "Monthly", zhHans: "每月"),
                 used: item.monthlyUsedUSD,
                 limit: item.monthlyLimitUSD,
                 progress: item.monthlyProgress,
@@ -65,7 +68,7 @@ struct SubscriptionQuotaCard: View {
             Spacer()
 
             if let days = item.daysRemaining {
-                Label("\(days)d left", systemImage: "calendar.badge.clock")
+                Label(strings.daysLeft(days), systemImage: "calendar.badge.clock")
                     .foregroundStyle(days <= 3 ? .orange : .secondary)
             }
         }
@@ -90,6 +93,9 @@ struct SubscriptionQuotaCard: View {
 
 struct QuotaProgressRow: View {
     let window: QuotaWindowDisplay
+    var language: AppLanguage = .en
+
+    private var strings: AppStrings { AppStrings(language: language) }
 
     private var tint: Color {
         switch window.severity {
@@ -133,7 +139,7 @@ struct QuotaProgressRow: View {
             .lineLimit(1)
             .minimumScaleFactor(0.75)
             .accessibilityElement(children: .ignore)
-            .accessibilityLabel("\(window.title) quota \(window.percentText), \(window.remainingText)")
+            .accessibilityLabel(strings.quotaAccessibility(title: window.title, percent: window.percentText, remaining: window.remainingText))
         }
     }
 }
diff --git a/Sources/Sub2APIStatusBar/SettingsView.swift b/Sources/Sub2APIStatusBar/SettingsView.swift
index c01902b..2fea7a0 100644
--- a/Sources/Sub2APIStatusBar/SettingsView.swift
+++ b/Sources/Sub2APIStatusBar/SettingsView.swift
@@ -5,6 +5,8 @@ struct SettingsView: View {
     @ObservedObject var model: MonitorViewModel
     @Environment(\.dismiss) private var dismiss
 
+    private var strings: AppStrings { AppStrings(language: model.settingsDraft.language) }
+
     var body: some View {
         VStack(spacing: 0) {
             header
@@ -52,7 +54,7 @@ struct SettingsView: View {
                 .frame(width: 34, height: 34)
                 .background(Color.blue.opacity(0.13), in: RoundedRectangle(cornerRadius: 8))
 
-            Text("Settings")
+            Text(strings.settings)
                 .font(.title2.bold())
 
             Spacer()
@@ -70,10 +72,10 @@ struct SettingsView: View {
     private var footer: some View {
         HStack {
             Spacer()
-            Button("Cancel") {
+            Button(strings.cancel) {
                 dismiss()
             }
-            Button("Save") {
+            Button(strings.save) {
                 model.saveSettings()
                 dismiss()
             }
@@ -89,8 +91,8 @@ struct AccountSettingsSection: View {
     @ObservedObject var model: MonitorViewModel
 
     var body: some View {
-        SettingsSection(title: "Accounts") {
-            SettingsControlRow(title: "Active Account") {
+        SettingsSection(title: AppStrings(language: model.settingsDraft.language).accounts) {
+            SettingsControlRow(title: AppStrings(language: model.settingsDraft.language).text(en: "Active Account", zhHans: "当前账户")) {
                 Picker("", selection: Binding(
                     get: { model.config.selectedAccountID ?? "" },
                     set: { id in
@@ -114,23 +116,36 @@ struct AccountSettingsSection: View {
 struct GeneralSettingsSection: View {
     @ObservedObject var model: MonitorViewModel
 
+    private var strings: AppStrings { AppStrings(language: model.settingsDraft.language) }
+
     var body: some View {
-        SettingsSection(title: "General") {
+        SettingsSection(title: strings.general) {
             VStack(spacing: 8) {
-                SettingsControlRow(title: "Base URL") {
+                SettingsControlRow(title: strings.baseURL) {
                     TextField("https://sub2api.example.com", text: $model.settingsDraft.baseURL)
                         .textFieldStyle(.roundedBorder)
                         .frame(maxWidth: .infinity)
                 }
 
-                SettingsControlRow(title: "Menu Bar") {
-                    Toggle("Show text", isOn: $model.settingsDraft.showsMenuBarText)
+                SettingsControlRow(title: strings.languageSetting) {
+                    Picker("", selection: $model.settingsDraft.language) {
+                        ForEach(AppLanguage.allCases) { language in
+                            Text(strings.languageDisplayName(language)).tag(language)
+                        }
+                    }
+                    .pickerStyle(.segmented)
+                    .controlSize(.small)
+                    .frame(maxWidth: 320, alignment: .leading)
+                }
+
+                SettingsControlRow(title: strings.menuBar) {
+                    Toggle(strings.showText, isOn: $model.settingsDraft.showsMenuBarText)
                 }
 
-                SettingsControlRow(title: "Metric") {
+                SettingsControlRow(title: strings.metric) {
                     Picker("", selection: $model.settingsDraft.menuBarMetric) {
                         ForEach(MenuBarMetric.allCases) { metric in
-                            Text(metric.displayName).tag(metric)
+                            Text(strings.menuBarMetricDisplayName(metric)).tag(metric)
                         }
                     }
                     .pickerStyle(.segmented)
@@ -139,14 +154,14 @@ struct GeneralSettingsSection: View {
                     .frame(maxWidth: .infinity)
                 }
 
-                SettingsControlRow(title: "Startup") {
-                    Toggle("Launch at login", isOn: Binding(
+                SettingsControlRow(title: strings.startup) {
+                    Toggle(strings.launchAtLogin, isOn: Binding(
                         get: { model.launchAtLoginEnabled },
                         set: { model.setLaunchAtLogin($0) }
                     ))
                 }
 
-                SettingsControlRow(title: "Refresh") {
+                SettingsControlRow(title: strings.refresh) {
                     Slider(value: $model.settingsDraft.refreshIntervalSeconds, in: 5...300, step: 5)
                         .frame(maxWidth: .infinity)
                     Text("\(Int(model.settingsDraft.refreshIntervalSeconds))s")
@@ -154,8 +169,8 @@ struct GeneralSettingsSection: View {
                         .frame(width: 42, alignment: .trailing)
                 }
 
-                SettingsControlRow(title: "Token") {
-                    SecureField("Bearer Token", text: $model.settingsDraft.authToken)
+                SettingsControlRow(title: strings.token) {
+                    SecureField(strings.bearerToken, text: $model.settingsDraft.authToken)
                         .textFieldStyle(.roundedBorder)
                         .frame(maxWidth: .infinity)
                 }
@@ -172,23 +187,23 @@ struct AlertSettingsSection: View {
     @ObservedObject var model: MonitorViewModel
 
     var body: some View {
-        SettingsSection(title: "Alerts") {
+        SettingsSection(title: AppStrings(language: model.settingsDraft.language).alerts) {
             VStack(spacing: 8) {
-                SettingsControlRow(title: "Notify") {
-                    Toggle("Usage insights", isOn: $model.settingsDraft.insightAlertSettings.isEnabled)
+                SettingsControlRow(title: AppStrings(language: model.settingsDraft.language).notify) {
+                    Toggle(AppStrings(language: model.settingsDraft.language).usageInsights, isOn: $model.settingsDraft.insightAlertSettings.isEnabled)
                 }
 
-                SettingsControlRow(title: "Level") {
+                SettingsControlRow(title: AppStrings(language: model.settingsDraft.language).text(en: "Level", zhHans: "级别")) {
                     Picker("", selection: $model.settingsDraft.insightAlertSettings.minimumSeverity) {
-                        Text("Warning").tag(MonitorSeverity.warning)
-                        Text("Error only").tag(MonitorSeverity.error)
+                        Text(AppStrings(language: model.settingsDraft.language).warning).tag(MonitorSeverity.warning)
+                        Text(AppStrings(language: model.settingsDraft.language).errorOnly).tag(MonitorSeverity.error)
                     }
                     .pickerStyle(.segmented)
                     .controlSize(.small)
                     .frame(maxWidth: 320, alignment: .leading)
                 }
 
-                SettingsControlRow(title: "Quiet") {
+                SettingsControlRow(title: AppStrings(language: model.settingsDraft.language).text(en: "Quiet", zhHans: "静默")) {
                     Slider(value: $model.settingsDraft.insightAlertSettings.cooldownMinutes, in: 5...360, step: 5)
                         .frame(maxWidth: .infinity)
                     Text("\(Int(model.settingsDraft.insightAlertSettings.cooldownMinutes))m")
@@ -206,7 +221,7 @@ struct InsightSettingsSection: View {
     @ObservedObject var model: MonitorViewModel
 
     var body: some View {
-        SettingsSection(title: "Insights") {
+        SettingsSection(title: AppStrings(language: model.settingsDraft.language).insights) {
             VStack(spacing: 8) {
                 ThresholdSliderRow(
                     title: "Quota warn",
@@ -430,7 +445,7 @@ struct LoginSettingsSection: View {
     let dismiss: DismissAction
 
     var body: some View {
-        SettingsSection(title: "Login") {
+        SettingsSection(title: AppStrings(language: model.settingsDraft.language).login) {
             TextField("Email", text: $model.loginEmail)
                 .textFieldStyle(.roundedBorder)
             SecureField("Password", text: $model.loginPassword)
@@ -438,7 +453,7 @@ struct LoginSettingsSection: View {
             Button {
                 model.loginAndSave()
             } label: {
-                Label("Login and Save Account", systemImage: "person.crop.circle.badge.plus")
+                Label(AppStrings(language: model.settingsDraft.language).loginAndSaveAccount, systemImage: "person.crop.circle.badge.plus")
             }
             .disabled(!LoginFormState(baseURL: model.settingsDraft.baseURL, email: model.loginEmail, password: model.loginPassword).canSubmit || model.isLoggingIn)
 
@@ -446,7 +461,7 @@ struct LoginSettingsSection: View {
                 model.disconnect()
                 dismiss()
             } label: {
-                Label("Remove Current Account", systemImage: "person.crop.circle.badge.xmark")
+                Label(AppStrings(language: model.settingsDraft.language).removeCurrentAccount, systemImage: "person.crop.circle.badge.xmark")
             }
             .disabled(model.config.selectedAccountID == nil && model.config.authToken.isEmpty && model.settingsDraft.authToken.isEmpty)
         }
@@ -457,20 +472,20 @@ struct DiagnosticsSettingsSection: View {
     @ObservedObject var model: MonitorViewModel
 
     var body: some View {
-        SettingsSection(title: "Diagnostics") {
+        SettingsSection(title: AppStrings(language: model.settingsDraft.language).diagnostics) {
             VStack(alignment: .leading, spacing: 8) {
                 HStack {
                     Button {
                         model.copySocialShareCard()
                     } label: {
-                        Label("Copy Share Card", systemImage: "square.and.arrow.up")
+                        Label(AppStrings(language: model.settingsDraft.language).copyShareCard, systemImage: "square.and.arrow.up")
                     }
                     .disabled(!model.snapshot.connected)
 
                     Button {
                         model.copyUsageReport()
                     } label: {
-                        Label("Copy Usage Report", systemImage: "chart.line.text.clipboard")
+                        Label(AppStrings(language: model.settingsDraft.language).copyUsageReport, systemImage: "chart.line.text.clipboard")
                     }
                     .disabled(!model.snapshot.connected)
                 }
@@ -479,19 +494,19 @@ struct DiagnosticsSettingsSection: View {
                     Button {
                         model.copyDiagnostics()
                     } label: {
-                        Label("Copy Diagnostics", systemImage: "doc.on.doc")
+                        Label(AppStrings(language: model.settingsDraft.language).copyDiagnostics, systemImage: "doc.on.doc")
                     }
 
                     Button {
                         model.copySupportBundle()
                     } label: {
-                        Label("Copy Support Bundle", systemImage: "doc.text")
+                        Label(AppStrings(language: model.settingsDraft.language).copySupportBundle, systemImage: "doc.text")
                     }
 
                     Button {
                         model.revealConfigFile()
                     } label: {
-                        Label("Show Config", systemImage: "folder")
+                        Label(AppStrings(language: model.settingsDraft.language).showConfig, systemImage: "folder")
                     }
                 }
             }
@@ -504,7 +519,7 @@ struct UpdateSettingsSection: View {
     @ObservedObject var model: MonitorViewModel
 
     var body: some View {
-        SettingsSection(title: "Updates") {
+        SettingsSection(title: AppStrings(language: model.settingsDraft.language).updates) {
             HStack {
                 Spacer()
                 if model.isCheckingForUpdates {
@@ -531,7 +546,7 @@ struct UpdateSettingsSection: View {
                     .font(.callout)
                     .foregroundStyle(.secondary)
             } else {
-                Text("Checks GitHub Releases for newer versions.")
+                Text(AppStrings(language: model.settingsDraft.language).githubReleaseCheck)
                     .font(.callout)
                     .foregroundStyle(.secondary)
             }
@@ -540,7 +555,7 @@ struct UpdateSettingsSection: View {
                 Button {
                     model.checkForUpdates()
                 } label: {
-                    Label("Check Now", systemImage: "arrow.clockwise")
+                    Label(AppStrings(language: model.settingsDraft.language).checkNow, systemImage: "arrow.clockwise")
                 }
                 .disabled(model.isCheckingForUpdates)
 
@@ -548,7 +563,7 @@ struct UpdateSettingsSection: View {
                     Button {
                         model.openLatestRelease()
                     } label: {
-                        Label("Open Release", systemImage: "safari")
+                        Label(AppStrings(language: model.settingsDraft.language).openRelease, systemImage: "safari")
                     }
                 }
             }
@@ -559,8 +574,11 @@ struct UpdateSettingsSection: View {
 
 struct UpdateAvailableBanner: View {
     let info: UpdateInfo
+    var language: AppLanguage = .en
     let openRelease: () -> Void
 
+    private var strings: AppStrings { AppStrings(language: language) }
+
     var body: some View {
         HStack(spacing: 10) {
             Image(systemName: "arrow.down.circle.fill")
@@ -569,7 +587,7 @@ struct UpdateAvailableBanner: View {
             VStack(alignment: .leading, spacing: 2) {
                 Text(info.statusText)
                     .font(.callout.weight(.semibold))
-                Text("Download the latest release from GitHub.")
+                Text(strings.downloadLatestRelease)
                     .font(.caption)
                     .foregroundStyle(.secondary)
             }
@@ -580,7 +598,7 @@ struct UpdateAvailableBanner: View {
                 Image(systemName: "safari")
             }
             .buttonStyle(.borderless)
-            .help("Open release")
+            .help(strings.openRelease)
         }
         .padding(10)
         .background(.regularMaterial, in: RoundedRectangle(cornerRadius: 8))
diff --git a/Sources/Sub2APIStatusBar/Sub2APIStatusBarApp.swift b/Sources/Sub2APIStatusBar/Sub2APIStatusBarApp.swift
index f991499..6b0db39 100644
--- a/Sources/Sub2APIStatusBar/Sub2APIStatusBarApp.swift
+++ b/Sources/Sub2APIStatusBar/Sub2APIStatusBarApp.swift
@@ -58,8 +58,9 @@ final class AppDelegate: NSObject, NSApplicationDelegate {
             return
         }
 
+        let strings = AppStrings(language: model.config.language)
         let severity = snapshot.severity(now: model.now, refreshIntervalSeconds: model.config.refreshIntervalSeconds)
-        let statusLabel = snapshot.statusLabel(now: model.now, refreshIntervalSeconds: model.config.refreshIntervalSeconds)
+        let statusLabel = snapshot.statusLabel(now: model.now, refreshIntervalSeconds: model.config.refreshIntervalSeconds, language: model.config.language)
 
         switch severity {
         case .healthy:
@@ -72,13 +73,13 @@ final class AppDelegate: NSObject, NSApplicationDelegate {
         button.image?.isTemplate = true
         button.imagePosition = .imageLeading
         button.title = snapshot.connected && model.config.showsMenuBarText
-            ? " \(snapshot.menuBarSummary(metric: model.config.menuBarMetric, now: model.now, refreshIntervalSeconds: model.config.refreshIntervalSeconds))"
+            ? " \(snapshot.menuBarSummary(metric: model.config.menuBarMetric, now: model.now, refreshIntervalSeconds: model.config.refreshIntervalSeconds, language: model.config.language))"
             : ""
 
         if let stats = snapshot.stats, snapshot.connected {
-            button.toolTip = "Sub2API \(statusLabel) - Today \(StatusFormatters.currency(stats.todayActualCost)), RPM \(String(format: "%.1f", stats.rpm))"
+            button.toolTip = strings.statusTooltip(statusLabel: statusLabel, todayCost: StatusFormatters.currency(stats.todayActualCost), rpm: String(format: "%.1f", stats.rpm))
         } else {
-            button.toolTip = "Sub2API \(statusLabel)"
+            button.toolTip = strings.sub2APIStatus(statusLabel)
         }
     }
 }

From d3aa3af1319d5ea24127a128fe2c87147ba52347 Mon Sep 17 00:00:00 2001
From: maple <maple@MacBook-Air.local>
Date: Tue, 2 Jun 2026 21:09:01 +0800
Subject: [PATCH 6/6] docs: document language setting

---
 CHANGELOG.md    | 3 +++
 README.md       | 2 ++
 README.zh-CN.md | 2 ++
 3 files changed, 7 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index cc7a8bc..b04e2ee 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,9 @@
 
 ## Unreleased
 
+- Added an in-app language setting with Auto, English, and Simplified Chinese options.
+- Localized the main app UI, menu bar status text, local insight notifications, recovery guidance, usage reports, diagnostics, support bundles, and social share copy/card labels.
+
 ## v0.1.11
 
 - Added a Simplified Chinese README and language switch links between English and Chinese docs.
diff --git a/README.md b/README.md
index b7e9cf2..0631acf 100644
--- a/README.md
+++ b/README.md
@@ -9,6 +9,7 @@ Sub2API Status Bar is a macOS menu bar companion for Sub2API users. It keeps dai
 ## Highlights
 
 - Native macOS menu bar app with a compact SwiftUI popover
+- In-app language setting with Auto, English, and Simplified Chinese options
 - Usage Insights that turn balance, quotas, monthly budget, spend trend, usage trend, model concentration, and latency into prioritized signals
 - Local proactive alerts for warning/error insights, with severity and quiet-period controls
 - Stale-data guardrail so the menu bar and local alerts warn when the last successful refresh is too old
@@ -81,6 +82,7 @@ To switch accounts or remove saved credentials, open Settings and choose **Disco
 
 Settings also includes:
 
+- **Language** to use Auto, English, or Simplified Chinese for app UI, menu bar status, local alerts, reports, diagnostics, support bundles, and share cards
 - **Show text in menu bar** for a compact always-visible usage summary
 - **Metric** to choose whether the menu bar emphasizes Auto, Spend, Balance, Quota, Tokens, or Requests
 - **Notify on insights** to receive local macOS alerts when important usage signals cross the configured level
diff --git a/README.zh-CN.md b/README.zh-CN.md
index 27a4310..e9416ab 100644
--- a/README.zh-CN.md
+++ b/README.zh-CN.md
@@ -9,6 +9,7 @@ Sub2API Status Bar 是一款面向 Sub2API 用户的 macOS 菜单栏助手。它
 ## 亮点
 
 - 原生 macOS 菜单栏应用，带紧凑的 SwiftUI 弹窗
+- 应用内语言设置，支持 Auto、English 和简体中文
 - Usage Insights 会把余额、额度、月度预算、花费趋势、用量趋势、模型成本集中度和延迟转成优先级信号
 - 本地主动提醒，支持 warning/error 级别和静默间隔设置
 - 数据过期保护：最近一次刷新太久时，菜单栏和本地提醒会提示数据已陈旧
@@ -81,6 +82,7 @@ swift run Sub2APIStatusBar
 
 Settings 还包含：
 
+- **Language**：为应用 UI、菜单栏状态、本地提醒、报告、诊断、支持包和分享卡片选择 Auto、English 或简体中文
 - **Show text in menu bar**：在菜单栏显示紧凑用量摘要
 - **Metric**：选择菜单栏优先展示 Auto、Spend、Balance、Quota、Tokens 或 Requests
 - **Notify on insights**：重要用量信号达到设定级别时发送本地 macOS 通知