diff --git a/.env.example b/.env.example
new file mode 100644
index 0000000..e15c008
--- /dev/null
+++ b/.env.example
@@ -0,0 +1 @@
+URL="base url. example: 'https://example.com' "
\ No newline at end of file
diff --git a/.gitignore b/.gitignore
index 6d4c0aa..cd4c6ec 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,6 +3,7 @@ dist/
 
 # generated types
 .astro/
+.vercel/
 
 # dependencies
 node_modules/
diff --git a/astro.config.mjs b/astro.config.mjs
index 02ee958..b2dcbd6 100644
--- a/astro.config.mjs
+++ b/astro.config.mjs
@@ -1,6 +1,7 @@
 import { defineConfig } from 'astro/config';
 import react from '@astrojs/react';
 import tailwindcss from '@astrojs/tailwind';
+import sitemap from '@astrojs/sitemap';
 import vercel from "@astrojs/vercel/static"
 
 // https://astro.build/config
@@ -8,6 +9,7 @@ export default defineConfig({
     server: {
         port: 8081
     },
+    site: process.env.URL,
     adapter: vercel({
         webAnalytics: {
             enabled: true,
@@ -21,5 +23,5 @@ export default defineConfig({
             }
         }
     },
-    integrations: [react(), tailwindcss()]
+    integrations: [sitemap(), react(), tailwindcss()]
 });
diff --git a/bun.lockb b/bun.lockb
index 529449a..049cdf9 100644
Binary files a/bun.lockb and b/bun.lockb differ
diff --git a/package.json b/package.json
index 0f9eeab..7580389 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "type": "module",
   "name": "tic-tac-toe-world",
-  "version": "1.2.6",
+  "version": "1.2.7",
   "scripts": {
     "dev": "astro dev --host",
     "start:build": "astro check && astro build && astro preview --host",
@@ -22,8 +22,9 @@
     "tailwindcss": "^3.4.1"
   },
   "devDependencies": {
-    "@types/react": "^18.2.48",
     "@astrojs/check": "^0.4.1",
+    "@astrojs/sitemap": "^3.0.5",
+    "@types/react": "^18.2.48",
     "@types/react-dom": "^18.2.18",
     "autoprefixer": "^10.4.17",
     "cssnano": "^6.0.3",
diff --git a/src/layouts/LayoutHTML.astro b/src/layouts/LayoutHTML.astro
index 44c4f65..d36fb3a 100644
--- a/src/layouts/LayoutHTML.astro
+++ b/src/layouts/LayoutHTML.astro
@@ -16,6 +16,7 @@ const { title, description = "" }: Props = Astro.props;
 		<title>{title}</title>
 		<meta name="title" content={title} />
 		<meta name="description" content={description} />
+		<link rel="sitemap" href="/sitemap-index.xml" />
 		<meta name="viewport" content="width=device-width" />
 		<link rel="icon" type="image/svg+xml" href="/favicon.svg" />
 		<slot name="head" />
diff --git a/src/pages/robot.txt.ts b/src/pages/robot.txt.ts
new file mode 100644
index 0000000..2da57c0
--- /dev/null
+++ b/src/pages/robot.txt.ts
@@ -0,0 +1,16 @@
+import type { APIRoute } from 'astro';
+
+const robotsTxt = `
+User-agent: *
+Allow: /
+
+Sitemap: ${new URL('sitemap-index.xml', process.env.URL).href}
+`.trim();
+
+export const GET: APIRoute = () => {
+  return new Response(robotsTxt, {
+    headers: {
+      'Content-Type': 'text/plain; charset=utf-8',
+    },
+  });
+};
\ No newline at end of file