diff --git a/src/client/lib/markdown.ts b/src/client/lib/markdown.ts
index c730150..f6d2a19 100644
--- a/src/client/lib/markdown.ts
+++ b/src/client/lib/markdown.ts
@@ -18,6 +18,15 @@ marked.use(
   })
 );
 
+// Custom renderer to wrap code blocks with copy button
+const renderer = new marked.Renderer();
+renderer.code = function ({ text, lang }: { text: string; lang?: string | undefined; escaped?: boolean }) {
+  const langLabel = lang ? `<span class="code-lang-label">${escapeHtml(lang)}</span>` : "";
+  return `<div class="code-block-wrapper">${langLabel}<button class="code-copy-btn" data-copy-code type="button">Copy</button><pre class="hljs"><code>${text}</code></pre></div>`;
+};
+
+marked.use({ renderer });
+
 export function renderMarkdown(text: string): string {
   if (!text) return "";
   try {
diff --git a/src/client/main.tsx b/src/client/main.tsx
index 0b11abd..eaf3b04 100644
--- a/src/client/main.tsx
+++ b/src/client/main.tsx
@@ -3,6 +3,23 @@ import ReactDOM from "react-dom/client";
 import { App } from "./app.js";
 import "./styles/main.css";
 
+// Delegated click handler for code block copy buttons
+document.addEventListener("click", (e) => {
+  const btn = (e.target as HTMLElement).closest("[data-copy-code]") as HTMLButtonElement | null;
+  if (!btn) return;
+  e.stopPropagation();
+  const wrapper = btn.closest(".code-block-wrapper");
+  const code = wrapper?.querySelector("code");
+  if (!code) return;
+  navigator.clipboard.writeText(code.textContent || "").then(() => {
+    btn.textContent = "Copied!";
+    setTimeout(() => { btn.textContent = "Copy"; }, 1500);
+  }).catch(() => {
+    btn.textContent = "Failed";
+    setTimeout(() => { btn.textContent = "Copy"; }, 1500);
+  });
+});
+
 ReactDOM.createRoot(document.getElementById("root")!).render(
   <React.StrictMode>
     <App />