feat(i18n): bind web language switch to cow_lang config

channel/web/chat.html

@@ -659,6 +659,31 @@
                                     </div>
                                 </div>
 
+                                <!-- Language Config Card -->
+                                <div class="bg-white dark:bg-[#1A1A1A] rounded-xl border border-slate-200 dark:border-white/10 p-6">
+                                    <div class="flex items-center gap-3 mb-5">
+                                        <div class="w-9 h-9 rounded-lg bg-sky-50 dark:bg-sky-900/30 flex items-center justify-center">
+                                            <i class="fas fa-language text-sky-500 text-sm"></i>
+                                        </div>
+                                        <h3 class="font-semibold text-slate-800 dark:text-slate-100" data-i18n="config_language">语言</h3>
+                                    </div>
+                                    <div class="space-y-4">
+                                        <div>
+                                            <label class="flex items-center gap-1.5 text-sm font-medium text-slate-600 dark:text-slate-400 mb-1.5">
+                                                <span data-i18n="config_language">语言</span>
+                                                <span class="cfg-tip" data-tip-key="config_language_hint"><i class="fas fa-circle-question"></i></span>
+                                            </label>
+                                            <div id="cfg-lang-select" class="cfg-dropdown" tabindex="0">
+                                                <div class="cfg-dropdown-selected">
+                                                    <span class="cfg-dropdown-text">--</span>
+                                                    <i class="fas fa-chevron-down cfg-dropdown-arrow"></i>
+                                                </div>
+                                                <div class="cfg-dropdown-menu"></div>
+                                            </div>
+                                        </div>
+                                    </div>
+                                </div>
+
                             </div>
                         </div>
                     </div>

channel/web/static/js/console.js

@@ -115,6 +115,7 @@ const I18N = {
         input_placeholder: '输入消息，或输入 / 使用指令',
         config_title: '配置管理', config_desc: '管理模型和 Agent 配置',
         config_model: '模型配置', config_agent: 'Agent 配置',
+        config_language: '语言', config_language_hint: '界面展示、命令文案、系统报错等使用的语言（与右上角切换同步）',
         config_model_advanced: '高级配置',
         config_channel: '通道配置',
         config_agent_enabled: 'Agent 模式',
@@ -310,6 +311,7 @@ const I18N = {
         input_placeholder: 'Type a message, or press / for commands',
         config_title: 'Configuration', config_desc: 'Manage model and agent settings',
         config_model: 'Model Configuration', config_agent: 'Agent Configuration',
+        config_language: 'Language', config_language_hint: 'Language for the UI, command text, system messages and more (synced with the top-right switch)',
         config_model_advanced: 'Advanced',
         config_channel: 'Channel Configuration',
         config_agent_enabled: 'Agent Mode',
@@ -454,14 +456,60 @@ function applyI18n() {
     if (langLabel) langLabel.textContent = currentLang === 'zh' ? '中文' : 'EN';
 }
 
-function toggleLanguage() {
+// Single entry point for switching language. Updates the in-memory language,
-    currentLang = currentLang === 'zh' ? 'en' : 'zh';
+// persists the user choice locally, re-renders the UI, and binds the choice to
+// the backend `cow_lang` config so logs / agent replies / CLI follow suit.
+function setLanguage(lang) {
+    const next = (lang === 'en') ? 'en' : 'zh';
+    if (next === currentLang) {
+        // Still persist + sync in case storage/backend drifted from the UI.
+        syncLanguageToBackend(next);
+        return;
+    }
+    currentLang = next;
     localStorage.setItem('cow_lang', currentLang);
     applyI18n();
     _applyInputTooltips();
     // Re-render views whose DOM is built in JS (data-i18n alone does not
     // cover strings interpolated via t() into innerHTML).
     try { rerenderDynamicViews(); } catch (e) {}
+    // Keep the language switch button and config selector visually in sync.
+    try { updateLangControls(); } catch (e) {}
+    syncLanguageToBackend(currentLang);
+}
+
+// Persist the language to the backend `cow_lang` config (best-effort; the UI
+// has already switched locally, so a network failure is non-blocking).
+function syncLanguageToBackend(lang) {
+    try {
+        fetch('/config', {
+            method: 'POST',
+            headers: { 'Content-Type': 'application/json' },
+            body: JSON.stringify({ updates: { cow_lang: lang } })
+        }).catch(() => {});
+    } catch (e) {}
+}
+
+// Reflect the current language on both the top-right toggle and the config
+// selector (if present), so the two entry points stay synchronized.
+function updateLangControls() {
+    const langLabel = document.getElementById('lang-label');
+    if (langLabel) langLabel.textContent = currentLang === 'zh' ? '中文' : 'EN';
+    // The config language picker is the custom .cfg-dropdown component. Only
+    // sync it once it has been initialized (i.e. the config panel was opened).
+    const sel = document.getElementById('cfg-lang-select');
+    if (sel && sel._ddValue !== undefined && sel._ddValue !== currentLang) {
+        sel._ddValue = currentLang;
+        const textEl = sel.querySelector('.cfg-dropdown-text');
+        if (textEl) textEl.textContent = currentLang === 'zh' ? '中文' : 'English';
+        sel.querySelectorAll('.cfg-dropdown-item').forEach(i => {
+            i.classList.toggle('active', i.dataset.value === currentLang);
+        });
+    }
+}
+
+function toggleLanguage() {
+    setLanguage(currentLang === 'zh' ? 'en' : 'zh');
 }
 
 // Refresh JS-rendered views after a language switch. Each branch uses the
@@ -3358,6 +3406,18 @@ function initConfigView(data) {
     document.getElementById('cfg-max-steps').value = data.agent_max_steps || 20;
     document.getElementById('cfg-enable-thinking').checked = data.enable_thinking === true;
 
+    // Reflect the current UI language (already resolved, may include the user's
+    // local choice) on the selector so it stays in sync with the top-right toggle.
+    const langSel = document.getElementById('cfg-lang-select');
+    if (langSel) {
+        initDropdown(
+            langSel,
+            [{ value: 'zh', label: '中文' }, { value: 'en', label: 'English' }],
+            currentLang,
+            (val) => setLanguage(val)
+        );
+    }
+
     const pwdInput = document.getElementById('cfg-password');
     const maskedPwd = data.web_password_masked || '';
     pwdInput.value = maskedPwd;

channel/web/web_channel.py

@@ -1535,6 +1535,7 @@ class ConfigHandler:
     ])
 
     EDITABLE_KEYS = {
+        "cow_lang",
         "model", "bot_type", "use_linkai",
         "open_ai_api_base", "deepseek_api_base", "qianfan_api_base", "claude_api_base", "gemini_api_base",
         "zhipu_ai_api_base", "moonshot_base_url", "ark_base_url", "custom_api_base", "mimo_api_base",
@@ -1643,6 +1644,15 @@ class ConfigHandler:
 
             logger.info(f"[WebChannel] Config updated: {list(applied.keys())}")
 
+            # Apply a language change immediately so backend logs, agent
+            # replies and CLI output switch without a restart.
+            if "cow_lang" in applied:
+                try:
+                    i18n.resolve_language(applied["cow_lang"])
+                    logger.info(f"[WebChannel] Language switched to: {i18n.get_language()}")
+                except Exception as lang_err:
+                    logger.warning(f"[WebChannel] Failed to apply language: {lang_err}")
+
             # Reset Bridge so that bot routing reflects the new config.
             # Without this, Bridge keeps its cached bot instance (e.g. LinkAIBot)
             # even after the user switches bot_type / use_linkai / model in UI.

cli/commands/process.py

@@ -298,6 +298,8 @@ def status():
         click.echo(_t(f"  模型: {cfg.get('model', 'unknown')}", f"  Model: {cfg.get('model', 'unknown')}"))
         mode = "Chat" if cfg.get("agent") is False else "Agent"
         click.echo(_t(f"  模式: {mode}", f"  Mode: {mode}"))
+        lang_label = "中文" if i18n.get_language() == "zh" else "English"
+        click.echo(_t(f"  语言: {lang_label}", f"  Language: {lang_label}"))
 
 
 @click.command()

plugins/cow_cli/cow_cli.py

@@ -465,6 +465,10 @@ class CowCliPlugin(Plugin):
         mode = "Chat" if cfg.get("agent") is False else "Agent"
         lines.append(_t(f"  模式: {mode}", f"  Mode: {mode}"))
 
+        from common import i18n
+        lang_label = "中文" if i18n.get_language() == "zh" else "English"
+        lines.append(_t(f"  语言: {lang_label}", f"  Language: {lang_label}"))
+
         session_id = self._get_session_id(e_context, fallback=session_id)
         agent = self._get_agent(session_id)
         if agent: