feat(tui): add Simplified Chinese UI translations and language selector

.changeset/tui-chinese-language-support.md

@@ -0,0 +1,5 @@
+---
+"@moonshot-ai/kimi-code": minor
+---
+
+Add Simplified Chinese UI translations and a language selector. Run /language or open Settings to switch between English and Chinese.

apps/kimi-code/package.json

@@ -37,6 +37,7 @@
   "imports": {
     "#/tui/theme": "./src/tui/theme/index.ts",
     "#/tui/commands": "./src/tui/commands/index.ts",
+    "#/tui/i18n": "./src/tui/i18n/index.ts",
     "#/cli/sub/web": "./src/cli/sub/web/index.ts",
     "#/cli/sub/web/*": "./src/cli/sub/web/*.ts",
     "#/generated/vis-web-asset": [

apps/kimi-code/src/tui/commands/config.ts

@@ -9,6 +9,7 @@ import {
 
 import { EditorSelectorComponent } from '../components/dialogs/editor-selector';
 import { EffortSelectorComponent } from '../components/dialogs/effort-selector';
+import { LanguageSelectorComponent } from '../components/dialogs/language-selector';
 import {
   ExperimentsSelectorComponent,
   type ExperimentalFeatureDraftChange,
@@ -20,6 +21,8 @@ import { SettingsSelectorComponent, type SettingsSelection } from '../components
 import { ThemeSelectorComponent } from '../components/dialogs/theme-selector';
 import { UpdatePreferenceSelectorComponent } from '../components/dialogs/update-preference-selector';
 import { DEFAULT_TUI_CONFIG, saveTuiConfig, type TuiConfig } from '../config';
+import { isLanguage, type Language } from '#/tui/i18n';
+import { t } from '#/tui/i18n';
 import type { ThemeName } from '#/tui/theme';
 import { currentTheme, isBuiltInTheme, lightColors, loadCustomThemeMerged } from '#/tui/theme';
 import { NO_ACTIVE_SESSION_MESSAGE } from '../constant/kimi-tui';
@@ -53,6 +56,7 @@ function hasConversationHistory(host: SlashCommandHost): boolean {
 function currentTuiConfig(host: SlashCommandHost): TuiConfig {
   return {
     theme: host.state.appState.theme,
+    language: host.state.appState.language,
     editorCommand: host.state.appState.editorCommand,
     disablePasteBurst: host.state.appState.disablePasteBurst ?? DEFAULT_TUI_CONFIG.disablePasteBurst,
     notifications: host.state.appState.notifications,
@@ -236,6 +240,19 @@ export async function handleThemeCommand(host: SlashCommandHost, args: string):
   await applyThemeChoice(host, theme);
 }
 
+export async function handleLanguageCommand(host: SlashCommandHost, args: string): Promise<void> {
+  const language = args.trim();
+  if (language.length === 0) {
+    showLanguagePicker(host);
+    return;
+  }
+  if (!isLanguage(language)) {
+    host.showError(`Unknown language: ${language}`);
+    return;
+  }
+  await applyLanguageChoice(host, language);
+}
+
 export async function handleModelCommand(host: SlashCommandHost, args: string): Promise<void> {
   const alias = args.trim();
   await refreshModelsForPicker(host);
@@ -609,6 +626,45 @@ async function applyThemeChoice(host: SlashCommandHost, theme: ThemeName): Promi
   host.showStatus(`Theme set to "${theme}"${detail}.`);
 }
 
+function showLanguagePicker(host: SlashCommandHost): void {
+  host.mountEditorReplacement(
+    new LanguageSelectorComponent({
+      currentValue: host.state.appState.language,
+      onSelect: (value) => {
+        host.restoreEditor();
+        void applyLanguageChoice(host, value);
+      },
+      onCancel: () => {
+        host.restoreEditor();
+      },
+    }),
+  );
+}
+
+async function applyLanguageChoice(host: SlashCommandHost, language: Language): Promise<void> {
+  if (language === host.state.appState.language) {
+    host.showStatus(`Language already set to "${language}".`);
+    return;
+  }
+
+  try {
+    await saveTuiConfig({
+      ...currentTuiConfig(host),
+      language,
+    });
+  } catch (error) {
+    host.showStatus(
+      `Failed to save language: ${formatErrorMessage(error)}`,
+      'error',
+    );
+    return;
+  }
+
+  host.applyLanguage(language);
+  host.track('language_switch', { language });
+  host.showStatus(`Language set to "${language}".`);
+}
+
 export function showPermissionPicker(host: SlashCommandHost): void {
   host.mountEditorReplacement(
     new PermissionSelectorComponent({
@@ -782,6 +838,7 @@ function handleSettingsSelection(host: SlashCommandHost, value: SettingsSelectio
     case 'model': showModelPicker(host); return;
     case 'permission': showPermissionPicker(host); return;
     case 'theme': showThemePicker(host); return;
+    case 'language': showLanguagePicker(host); return;
     case 'editor': showEditorPicker(host); return;
     case 'experiments': void showExperimentsPanel(host); return;
     case 'upgrade': showUpdatePreferencePicker(host); return;

apps/kimi-code/src/tui/commands/dispatch.ts

@@ -3,6 +3,7 @@ import type { DeviceAuthorization } from '@moonshot-ai/kimi-code-oauth';
 import type { KimiHarness, Session } from '@moonshot-ai/kimi-code-sdk';
 
 import type { ColorToken, ThemeName } from '#/tui/theme';
+import type { Language } from '#/tui/i18n';
 
 import { LLM_NOT_SET_MESSAGE } from '../constant/kimi-tui';
 import type { AuthFlowController } from '../controllers/auth-flow';
@@ -27,6 +28,7 @@ import {
   handleCompactCommand,
   handleEditorCommand,
   handleEffortCommand,
+  handleLanguageCommand,
   handleModelCommand,
   handlePlanCommand,
   handleThemeCommand,
@@ -69,6 +71,7 @@ export {
   handleCompactCommand,
   handleEditorCommand,
   handleEffortCommand,
+  handleLanguageCommand,
   handleModelCommand,
   handlePlanCommand,
   handleThemeCommand,
@@ -134,6 +137,9 @@ export interface SlashCommandHost {
   applyTheme(theme: ThemeName, resolved?: ResolvedTheme): Promise<void>;
   refreshTerminalThemeTracking(): void;
 
+  // Language
+  applyLanguage(language: Language): void;
+
   // Dispatch
   stop(exitCode?: number): Promise<void>;
   setExitOpenUrl(url: string): void;
@@ -300,6 +306,9 @@ async function handleBuiltInSlashCommand(
     case 'theme':
       await handleThemeCommand(host, args);
       return;
+    case 'language':
+      await handleLanguageCommand(host, args);
+      return;
     case 'model':
       await handleModelCommand(host, args);
       return;

apps/kimi-code/src/tui/commands/index.ts

@@ -13,6 +13,7 @@ export { handleCopyCommand } from './copy';
 export {
   handleCompactCommand,
   handleEditorCommand,
+  handleLanguageCommand,
   handleModelCommand,
   handlePlanCommand,
   handleThemeCommand,

apps/kimi-code/src/tui/commands/registry.ts

@@ -360,6 +360,13 @@ export const BUILTIN_SLASH_COMMANDS = [
     priority: 60,
     availability: 'always',
   },
+  {
+    name: 'language',
+    aliases: ['lang'],
+    description: 'Set the TUI display language',
+    priority: 60,
+    availability: 'always',
+  },
   {
     name: 'logout',
     aliases: ['disconnect'],

apps/kimi-code/src/tui/commands/reload.ts

@@ -49,6 +49,7 @@ export async function applyReloadedTuiConfig(
     notifications: config.notifications,
     upgrade: config.upgrade,
   });
+  host.applyLanguage(config.language);
   host.state.editor.setDisablePasteBurst(config.disablePasteBurst);
 }
 

apps/kimi-code/src/tui/components/chrome/footer.ts

@@ -28,6 +28,7 @@ import {
   usagePercent,
   usagePercentFromRatio,
 } from '#/utils/usage/usage-format';
+import { t } from '#/tui/i18n';
 
 const MAX_CWD_SEGMENTS = 3;
 const GOAL_TIMER_INTERVAL_MS = 1_000;
@@ -167,9 +168,9 @@ function shortenCwd(path: string): string {
 function formatContextStatus(usage: number, tokens?: number, maxTokens?: number): string {
   if (maxTokens !== undefined && maxTokens > 0 && tokens !== undefined) {
     const pct = String(usagePercent(tokens, maxTokens));
-    return `context: ${pct}% (${formatTokenCount(tokens)}/${formatTokenCount(maxTokens)})`;
+    return `${t('footer.context', { pct })} (${formatTokenCount(tokens)}/${formatTokenCount(maxTokens)})`;
   }
-  return `context: ${String(usagePercentFromRatio(usage))}%`;
+  return `${t('footer.context', { pct: String(usagePercentFromRatio(usage)) })}`;
 }
 
 export function formatFooterGitBadge(status: GitStatus, colors: ColorPalette): string {

apps/kimi-code/src/tui/components/chrome/welcome.ts

@@ -10,6 +10,7 @@ import chalk from 'chalk';
 import { effectiveModelAlias } from '@moonshot-ai/kimi-code-sdk';
 
 import { isRainbowDancing, renderDanceWelcomeHeader } from '#/tui/easter-eggs/dance';
+import { t } from '#/tui/i18n';
 import type { AppState } from '#/tui/types';
 import { currentTheme } from '#/tui/theme';
 
@@ -30,14 +31,14 @@ export class WelcomeComponent implements Component {
     const effectiveActiveModel = activeModel === undefined ? undefined : effectiveModelAlias(activeModel);
 
     if (safeWidth < 24) {
-      const title = chalk.bold.hex(currentTheme.palette.primary)('Welcome to Kimi Code!');
+      const title = chalk.bold.hex(currentTheme.palette.primary)(t('welcome.title'));
       const prompt = isLoggedOut
-        ? chalk.hex(currentTheme.palette.warning)('Run /login or /provider to get started.')
-        : chalk.hex(currentTheme.palette.textDim)('Send /help for help information.');
+        ? chalk.hex(currentTheme.palette.warning)(t('welcome.loggedOutHint'))
+        : chalk.hex(currentTheme.palette.textDim)(t('welcome.loggedInHint'));
       const model = isLoggedOut
-        ? chalk.hex(currentTheme.palette.warning)('not set, run /login or /provider')
+        ? chalk.hex(currentTheme.palette.warning)(t('welcome.notSet'))
         : (effectiveActiveModel?.displayName ?? effectiveActiveModel?.model ?? this.state.model);
-      return ['', title, prompt, `Model: ${model}`].map((line) =>
+      return ['', title, prompt, `${t('welcome.model')} ${model}`].map((line) =>
         truncateToWidth(line, safeWidth, '…'),
       );
     }
@@ -52,14 +53,14 @@ export class WelcomeComponent implements Component {
     const textWidth = Math.max(4, innerWidth - logoWidth - gap.length);
 
     const rightRow0 = truncateToWidth(
-      chalk.bold.hex(currentTheme.palette.primary)('Welcome to Kimi Code!'),
+      chalk.bold.hex(currentTheme.palette.primary)(t('welcome.title')),
       textWidth,
       '…',
     );
     const dim = chalk.hex(currentTheme.palette.textDim);
     const labelStyle = chalk.bold.hex(currentTheme.palette.textDim);
     const rightRow1 = truncateToWidth(
-      dim(isLoggedOut ? 'Run /login or /provider to get started.' : 'Send /help for help information.'),
+      dim(isLoggedOut ? t('welcome.loggedOutHint') : t('welcome.loggedInHint')),
       textWidth,
       '…',
     );
@@ -73,18 +74,18 @@ export class WelcomeComponent implements Component {
     }
 
     const modelValue = isLoggedOut
-      ? chalk.hex(currentTheme.palette.warning)('not set, run /login or /provider')
+      ? chalk.hex(currentTheme.palette.warning)(t('welcome.notSet'))
       : (effectiveActiveModel?.displayName ?? effectiveActiveModel?.model ?? this.state.model);
 
     const infoLines = [
-      labelStyle('Directory: ') + this.state.workDir,
-      labelStyle('Session:   ') + this.state.sessionId,
-      labelStyle('Model:     ') + modelValue,
-      labelStyle('Version:   ') + this.state.version,
+      labelStyle(t('welcome.directory')) + ' ' + this.state.workDir,
+      labelStyle(t('welcome.session')) + ' ' + this.state.sessionId,
+      labelStyle(t('welcome.model')) + ' ' + modelValue,
+      labelStyle(t('welcome.version')) + ' ' + this.state.version,
     ];
 
     if (this.state.mcpServersSummary) {
-      infoLines.push(labelStyle('MCP:       ') + this.state.mcpServersSummary);
+      infoLines.push(labelStyle(t('welcome.mcp')) + ' ' + this.state.mcpServersSummary);
     }
 
     const contentLines: string[] = [...renderedHeaderLines, '', ...infoLines];

apps/kimi-code/src/tui/components/dialogs/language-selector.ts

@@ -0,0 +1,31 @@
+import { ChoicePickerComponent, type ChoiceOption } from './choice-picker';
+
+import type { Language } from '#/tui/i18n';
+import { t } from '#/tui/i18n';
+
+function languageOptions(): readonly ChoiceOption[] {
+  return [
+    { value: 'en', label: 'English' },
+    { value: 'zh', label: '中文' },
+  ];
+}
+
+export interface LanguageSelectorOptions {
+  readonly currentValue: Language;
+  readonly onSelect: (language: Language) => void;
+  readonly onCancel: () => void;
+}
+
+export class LanguageSelectorComponent extends ChoicePickerComponent {
+  constructor(opts: LanguageSelectorOptions) {
+    super({
+      title: t('language.label'),
+      options: [...languageOptions()],
+      currentValue: opts.currentValue,
+      onSelect: (value) => {
+        opts.onSelect(value as Language);
+      },
+      onCancel: opts.onCancel,
+    });
+  }
+}