diff --git a/code-editor/bun.lockb b/code-editor/bun.lockb
index 0b2d609..2793933 100755
Binary files a/code-editor/bun.lockb and b/code-editor/bun.lockb differ
diff --git a/code-editor/package.json b/code-editor/package.json
index 6e3f00c..ba41223 100644
--- a/code-editor/package.json
+++ b/code-editor/package.json
@@ -18,10 +18,15 @@
     "clsx": "^2.1.1",
     "devicons-react": "^1.4.0",
     "lucide-react": "^0.469.0",
+    "monaco-editor": "0.36.1",
+    "monaco-languageclient": "5.0.1",
+    "normalize-url": "~8.0.0",
     "react": "^18.3.1",
     "react-dom": "^18.3.1",
     "tailwind-merge": "^2.6.0",
-    "tailwindcss-animate": "^1.0.7"
+    "tailwindcss-animate": "^1.0.7",
+    "vscode-languageclient": "~8.1.0",
+    "vscode-ws-jsonrpc": "3.0.0"
   },
   "devDependencies": {
     "@eslint/js": "^9.17.0",
diff --git a/code-editor/src/App.tsx b/code-editor/src/App.tsx
index 284c505..e30fbe1 100644
--- a/code-editor/src/App.tsx
+++ b/code-editor/src/App.tsx
@@ -3,19 +3,38 @@ import {
   DEFAULT_EDITOR_THEME,
   DEFAULT_EDITOR_LANGUAGE,
 } from "@/config";
-import { useState } from "react";
 import * as monaco from "monaco-editor";
 import { highlighter } from "@/lib/shiki";
 import { Bot, CodeXml } from "lucide-react";
 import { shikiToMonaco } from "@shikijs/monaco";
-import { DiffEditor, Editor, Monaco } from "@monaco-editor/react";
+import { connectToLanguageServer } from "@/lib/lsp";
+import { useEffect, useRef, useState } from "react";
 import { ScrollArea, ScrollBar } from "@/components/ui/scroll-area";
+import { DiffEditor, Editor, Monaco, loader } from "@monaco-editor/react";
 import { Tabs, TabsContent, TabsList, TabsTrigger } from "@/components/ui/tabs";
 
+loader.config({ monaco });
+
 function App() {
   const [language, setLanguage] = useState(DEFAULT_EDITOR_LANGUAGE);
   const [theme, setTheme] = useState(DEFAULT_EDITOR_THEME);
   const file = DEFAULT_FILES[language];
+  const webSocketRef = useRef<WebSocket | null>(null);
+
+  useEffect(() => {
+    if (webSocketRef.current) {
+      webSocketRef.current.close();
+    }
+    connectToLanguageServer(language).then((webSocket) => {
+      webSocketRef.current = webSocket;
+    });
+
+    return () => {
+      if (webSocketRef.current) {
+        webSocketRef.current.close();
+      }
+    };
+  }, [language]);
 
   return (
     <div className="h-screen bg-[#282c34] dark overflow-hidden">
@@ -71,10 +90,7 @@ function App() {
             beforeMount={async (monaco: Monaco) => {
               shikiToMonaco(await highlighter, monaco);
             }}
-            onMount={(
-              editor: monaco.editor.IStandaloneCodeEditor,
-              monaco: Monaco
-            ) => {
+            onMount={(editor: monaco.editor.IStandaloneCodeEditor) => {
               const value = editor.getModel()?.getValue();
               if (value !== undefined) {
                 window.parent.postMessage(
@@ -82,6 +98,9 @@ function App() {
                   "*"
                 );
               }
+              connectToLanguageServer(language).then((webSocket) => {
+                webSocketRef.current = webSocket;
+              });
             }}
             onChange={(value) => {
               if (value !== undefined) {
diff --git a/code-editor/src/lib/lsp.ts b/code-editor/src/lib/lsp.ts
new file mode 100644
index 0000000..cdbfcd6
--- /dev/null
+++ b/code-editor/src/lib/lsp.ts
@@ -0,0 +1,82 @@
+import {
+  toSocket,
+  WebSocketMessageReader,
+  WebSocketMessageWriter,
+} from "vscode-ws-jsonrpc";
+import {
+  CloseAction,
+  ErrorAction,
+  MessageTransports,
+} from "vscode-languageclient";
+import normalizeUrl from "normalize-url";
+import { MonacoLanguageClient } from "monaco-languageclient";
+
+export const SUPPORTED_LSP_LANGUAGES: {
+  [key: string]: { hostname: string; port: number | null; path: string };
+} = {
+  c: {
+    hostname: "c.litchi.icu",
+    port: null,
+    path: "/clangd",
+  },
+  cpp: {
+    hostname: "cpp.litchi.icu",
+    port: null,
+    path: "/clangd",
+  },
+};
+
+function createUrl(
+  hostname: string,
+  port: number | null,
+  path: string
+): string {
+  const protocol = location.protocol === "https:" ? "wss" : "ws";
+  return port !== null
+    ? normalizeUrl(`${protocol}://${hostname}:${port}${path}`)
+    : normalizeUrl(`${protocol}://${hostname}${path}`);
+}
+
+function createLanguageClient(
+  transports: MessageTransports
+): MonacoLanguageClient {
+  return new MonacoLanguageClient({
+    name: "Judge4c Language Client",
+    clientOptions: {
+      documentSelector: ["c", "cpp"],
+      errorHandler: {
+        error: () => ({ action: ErrorAction.Continue }),
+        closed: () => ({ action: CloseAction.DoNotRestart }),
+      },
+    },
+    connectionProvider: {
+      get: () => {
+        return Promise.resolve(transports);
+      },
+    },
+  });
+}
+
+function createWebSocket(url: string) {
+  const webSocket = new WebSocket(url);
+  webSocket.onopen = () => {
+    const socket = toSocket(webSocket);
+    const reader = new WebSocketMessageReader(socket);
+    const writer = new WebSocketMessageWriter(socket);
+    const languageClient = createLanguageClient({
+      reader,
+      writer,
+    });
+    languageClient.start();
+    reader.onClose(() => languageClient.stop());
+  };
+  return webSocket;
+}
+
+export async function connectToLanguageServer(
+  language: string
+): Promise<WebSocket> {
+  const { hostname, port, path } = SUPPORTED_LSP_LANGUAGES[language];
+  const url = createUrl(hostname, port, path);
+  return createWebSocket(url);
+}