diff --git a/frontend/src/components/chat/ChatInput.tsx b/frontend/src/components/chat/ChatInput.tsx
index b1cee26688..21cbd17a02 100644
--- a/frontend/src/components/chat/ChatInput.tsx
+++ b/frontend/src/components/chat/ChatInput.tsx
@@ -62,7 +62,7 @@ function ChatInput({ disabled = false, onSendMessage }: ChatInputProps) {
             ? "cursor-not-allowed border-neutral-400 text-neutral-400"
             : "hover:bg-neutral-500 ",
         )}
-        aria-label="Send message"
+        aria-label={t(I18nKey.CHAT_INTERFACE$TOOLTIP_SEND_MESSAGE)}
       >
         <VscArrowUp />
       </button>
diff --git a/frontend/src/components/chat/ChatMessage.tsx b/frontend/src/components/chat/ChatMessage.tsx
index 095b08c6ca..6b4660eeb3 100644
--- a/frontend/src/components/chat/ChatMessage.tsx
+++ b/frontend/src/components/chat/ChatMessage.tsx
@@ -2,8 +2,10 @@ import React, { useState } from "react";
 import Markdown from "react-markdown";
 import { FaClipboard } from "react-icons/fa";
 import { twMerge } from "tailwind-merge";
+import { useTranslation } from "react-i18next";
 import { code } from "../markdown/code";
 import toast from "#/utils/toast";
+import { I18nKey } from "#/i18n/declaration";
 
 interface MessageProps {
   message: Message;
@@ -18,14 +20,18 @@ function ChatMessage({ message }: MessageProps) {
     message.sender === "user" ? "bg-neutral-700 self-end" : "bg-neutral-500",
   );
 
+  const { t } = useTranslation();
   const copyToClipboard = () => {
     navigator.clipboard
       .writeText(message.content)
       .then(() => {
-        toast.info("Message copied to clipboard!");
+        toast.info(t(I18nKey.CHAT_INTERFACE$CHAT_MESSAGE_COPIED));
       })
-      .catch((error) => {
-        toast.error("copy-error", `Failed to copy message: ${error}`);
+      .catch(() => {
+        toast.error(
+          "copy-error",
+          t(I18nKey.CHAT_INTERFACE$CHAT_MESSAGE_COPY_FAILED),
+        );
       });
   };
 
@@ -40,7 +46,7 @@ function ChatMessage({ message }: MessageProps) {
         <button
           onClick={copyToClipboard}
           className="absolute top-1 right-1 p-1 bg-neutral-600 rounded hover:bg-neutral-500 transition-opacity opacity-75 hover:opacity-100"
-          aria-label="Copy message"
+          aria-label={t(I18nKey.CHAT_INTERFACE$TOOLTIP_COPY_MESSAGE)}
           type="button"
         >
           <FaClipboard />
diff --git a/frontend/src/components/file-explorer/FileExplorer.tsx b/frontend/src/components/file-explorer/FileExplorer.tsx
index 6ba14947da..06d4ba8ca0 100644
--- a/frontend/src/components/file-explorer/FileExplorer.tsx
+++ b/frontend/src/components/file-explorer/FileExplorer.tsx
@@ -7,6 +7,7 @@ import {
 } from "react-icons/io";
 import { useDispatch, useSelector } from "react-redux";
 import { IoFileTray } from "react-icons/io5";
+import { useTranslation } from "react-i18next";
 import { twMerge } from "tailwind-merge";
 import AgentState from "#/types/AgentState";
 import { setRefreshID } from "#/state/codeSlice";
@@ -15,6 +16,7 @@ import IconButton from "../IconButton";
 import ExplorerTree from "./ExplorerTree";
 import toast from "#/utils/toast";
 import { RootState } from "#/store";
+import { I18nKey } from "#/i18n/declaration";
 
 interface ExplorerActionsProps {
   onRefresh: () => void;
@@ -92,7 +94,7 @@ function FileExplorer() {
   const { curAgentState } = useSelector((state: RootState) => state.agent);
   const fileInputRef = React.useRef<HTMLInputElement | null>(null);
   const dispatch = useDispatch();
-
+  const { t } = useTranslation();
   const selectFileInput = () => {
     fileInputRef.current?.click(); // Trigger the file browser
   };
@@ -113,7 +115,7 @@ function FileExplorer() {
       await uploadFiles(toAdd);
       await refreshWorkspace();
     } catch (error) {
-      toast.error("ws", "Error uploading file");
+      toast.error("ws", t(I18nKey.EXPLORER$UPLOAD_ERROR_MESSAGE));
     }
   };
 
@@ -158,7 +160,9 @@ function FileExplorer() {
           className="z-10 absolute flex flex-col justify-center items-center bg-black top-0 bottom-0 left-0 right-0 opacity-65"
         >
           <IoFileTray size={32} />
-          <p className="font-bold text-xl">Drop Files Here</p>
+          <p className="font-bold text-xl">
+            {t(I18nKey.EXPLORER$LABEL_DROP_FILES)}
+          </p>
         </div>
       )}
       <div
@@ -176,7 +180,7 @@ function FileExplorer() {
           >
             {!isHidden && (
               <div className="ml-1 text-neutral-300 font-bold text-sm">
-                Workspace
+                {t(I18nKey.EXPLORER$LABEL_WORKSPACE)}
               </div>
             )}
             <ExplorerActions
diff --git a/frontend/src/components/modals/settings/SettingsModal.tsx b/frontend/src/components/modals/settings/SettingsModal.tsx
index 0ead721212..3eecccb2c5 100644
--- a/frontend/src/components/modals/settings/SettingsModal.tsx
+++ b/frontend/src/components/modals/settings/SettingsModal.tsx
@@ -58,7 +58,7 @@ function SettingsModal({ isOpen, onOpenChange }: SettingsProps) {
         setModels(await fetchModels());
         setAgents(await fetchAgents());
       } catch (error) {
-        toast.error("settings", "Failed to fetch models and agents");
+        toast.error("settings", t(I18nKey.CONFIGURATION$ERROR_FETCH_MODELS));
       } finally {
         setLoading(false);
       }
diff --git a/frontend/src/i18n/translation.json b/frontend/src/i18n/translation.json
index 89b435741d..2cee273df6 100644
--- a/frontend/src/i18n/translation.json
+++ b/frontend/src/i18n/translation.json
@@ -268,6 +268,46 @@
     "en": "Please stop the agent before editing these settings.",
     "de": "Bitte beenden Sie den Agenten vor der Bearbeitung der Einstellungen."
   },
+  "CONFIGURATION$ERROR_FETCH_MODELS": {
+    "en": "Failed to fetch models and agents",
+    "zh-CN": "获取模型和智能体失败",
+    "de": "Fehler beim Abrufen der Modelle und Agenten"
+  },
+  "SESSION$SERVER_CONNECTED_MESSAGE": {
+    "en": "Connected to server",
+    "zh-CN": "已连接到服务器",
+    "de": "Verbindung zum Server hergestellt"
+  },
+  "SESSION$SESSION_HANDLING_ERROR_MESSAGE": {
+    "en": "Error handling message",
+    "zh-CN": "处理消息时发生错误",
+    "de": "Fehler beim Verarbeiten der Nachricht"
+  },
+  "SESSION$SESSION_CONNECTION_ERROR_MESSAGE": {
+    "en": "Error connecting to session",
+    "zh-CN": "连接到会话时发生错误",
+    "de": "Verbindung zur Sitzung fehlgeschlagen"
+  },
+  "SESSION$SOCKET_NOT_INITIALIZED_ERROR_MESSAGE": {
+    "en": "Socket not initialized",
+    "zh-CN": "Socket 未初始化",
+    "de": "Socket nicht initialisiert"
+  },
+  "EXPLORER$UPLOAD_ERROR_MESSAGE": {
+    "en": "Error uploading file",
+    "zh-CN": "上传文件时发生错误",
+    "de": "Fehler beim Hochladen der Datei"
+  },
+  "EXPLORER$LABEL_DROP_FILES": {
+    "en": "Drop files here",
+    "zh-CN": "将文件拖到这里",
+    "de": "Dateien hier ablegen"
+  },
+  "EXPLORER$LABEL_WORKSPACE": {
+    "en": "Workspace",
+    "zh-CN": "工作区",
+    "de": "Arbeitsbereich"
+  },
   "LOAD_SESSION$MODAL_TITLE": {
     "en": "Return to existing session?",
     "de": "Zurück zu vorhandener Sitzung?",
@@ -394,6 +434,26 @@
     "ar": "إرسال",
     "fr": "Envoyer"
   },
+  "CHAT_INTERFACE$CHAT_MESSAGE_COPIED": {
+    "en": "Message copied to clipboard",
+    "zh-CN": "消息已复制到剪贴板",
+    "de": "Nachricht in die Zwischenablage kopiert"
+  },
+  "CHAT_INTERFACE$CHAT_MESSAGE_COPY_FAILED": {
+    "en": "Failed to copy message to clipboard",
+    "zh-CN": "复制消息到剪贴板失败",
+    "de": "Nachricht konnte nicht in die Zwischenablage kopiert werden"
+  },
+  "CHAT_INTERFACE$TOOLTIP_COPY_MESSAGE": {
+    "en": "Copy message",
+    "zh-CN": "复制消息",
+    "de": "Nachricht kopieren"
+  },
+  "CHAT_INTERFACE$TOOLTIP_SEND_MESSAGE": {
+    "en": "Send message",
+    "zh-CN": "发送消息",
+    "de": "Nachricht senden"
+  },
   "CHAT_INTERFACE$INITIAL_MESSAGE": {
     "en": "Hi! I'm OpenDevin, an AI Software Engineer. What would you like to build with me today?",
     "zh-CN": "你好！我是 OpenDevin，一名 AI 软件工程师。今天想和我一起编写什么程序呢?",
diff --git a/frontend/src/services/session.ts b/frontend/src/services/session.ts
index 209df12f37..09bcdc7b0d 100644
--- a/frontend/src/services/session.ts
+++ b/frontend/src/services/session.ts
@@ -1,8 +1,12 @@
+import i18next from "i18next";
 import toast from "#/utils/toast";
 import { handleAssistantMessage } from "./actions";
 import { getToken, setToken, clearToken } from "./auth";
 import ActionType from "#/types/ActionType";
 import { getSettings } from "./settings";
+import { I18nKey } from "#/i18n/declaration";
+
+const translate = (key: I18nKey) => i18next.t(key);
 
 class Session {
   private static _socket: WebSocket | null = null;
@@ -66,10 +70,12 @@ class Session {
 
   private static _setupSocket(): void {
     if (!Session._socket) {
-      throw new Error("Socket is not initialized.");
+      throw new Error(
+        translate(I18nKey.SESSION$SOCKET_NOT_INITIALIZED_ERROR_MESSAGE),
+      );
     }
     Session._socket.onopen = (e) => {
-      toast.success("ws", "Connected to server.");
+      toast.success("ws", translate(I18nKey.SESSION$SERVER_CONNECTED_MESSAGE));
       Session._connecting = false;
       Session._initializeAgent();
       Session.callbacks.open?.forEach((callback) => {
@@ -84,7 +90,10 @@ class Session {
         Session._history.push(data);
       } catch (err) {
         // TODO: report the error
-        toast.error("ws", "Error handing message.");
+        toast.error(
+          "ws",
+          translate(I18nKey.SESSION$SESSION_HANDLING_ERROR_MESSAGE),
+        );
         return;
       }
       if (data.error && data.error_code === 401) {
@@ -101,8 +110,10 @@ class Session {
     };
 
     Session._socket.onerror = () => {
-      const msg = "Connection failed. Retry...";
-      toast.error("ws", msg);
+      toast.error(
+        "ws",
+        translate(I18nKey.SESSION$SESSION_CONNECTION_ERROR_MESSAGE),
+      );
     };
 
     Session._socket.onclose = () => {
@@ -135,15 +146,19 @@ class Session {
       return;
     }
     if (!Session.isConnected()) {
-      throw new Error("Not connected to server.");
+      throw new Error(
+        translate(I18nKey.SESSION$SESSION_CONNECTION_ERROR_MESSAGE),
+      );
     }
 
     if (Session.isConnected()) {
       Session._socket?.send(message);
       Session._history.push(JSON.parse(message));
     } else {
-      const msg = "Connection failed. Retry...";
-      toast.error("ws", msg);
+      toast.error(
+        "ws",
+        translate(I18nKey.SESSION$SESSION_CONNECTION_ERROR_MESSAGE),
+      );
     }
   }