diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 94fad9c..90d033d 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        node-version: ['18.x', '20.x']
+        node-version: ['18.18.x', '20.x']
     steps:
       - uses: actions/checkout@v4
 
diff --git a/README.md b/README.md
index d057f70..003737b 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,7 @@
 # deAPI Tester
 
 [![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](https://opensource.org/licenses/MIT)
-[![Node.js 18+](https://img.shields.io/badge/Node.js-18%2B-green.svg)](https://nodejs.org/)
+[![Node.js 18.18.0+](https://img.shields.io/badge/Node.js-18.18.0%2B-green.svg)](https://nodejs.org/)
 [![Next.js 15](https://img.shields.io/badge/Next.js-15-black.svg)](https://nextjs.org/)
 [![Docker](https://img.shields.io/badge/Docker-ready-blue.svg)](https://www.docker.com/)
 
diff --git a/package.json b/package.json
index 0adc4b2..ffc85f5 100644
--- a/package.json
+++ b/package.json
@@ -7,6 +7,9 @@
     "url": "https://deapi.ai"
   },
   "license": "MIT",
+  "engines": {
+    "node": ">=18.18.0"
+  },
   "repository": {
     "type": "git",
     "url": "https://github.com/deapi-ai/deapi-tester.git"
diff --git a/src/app/layout.tsx b/src/app/layout.tsx
index a836226..422927f 100644
--- a/src/app/layout.tsx
+++ b/src/app/layout.tsx
@@ -2,10 +2,23 @@ import type { Metadata } from 'next';
 import './globals.css';
 import { Providers } from '@/components/Providers';
 
+function getMetadataBaseUrl(): string {
+  const siteUrl = process.env.NEXT_PUBLIC_SITE_URL;
+  if (!siteUrl) {
+    return 'http://localhost:3000';
+  }
+  // Ensure URL has a protocol
+  if (!/^https?:\/\//i.test(siteUrl)) {
+    console.warn(
+      `NEXT_PUBLIC_SITE_URL ('${siteUrl}') missing protocol. Using default: http://localhost:3000`
+    );
+    return 'http://localhost:3000';
+  }
+  return siteUrl;
+}
+
 export const metadata: Metadata = {
-  metadataBase: new URL(
-    process.env.NEXT_PUBLIC_SITE_URL || 'http://localhost:3000'
-  ),
+  metadataBase: new URL(getMetadataBaseUrl()),
   title: 'deAPI Tester — Test AI Inference Endpoints',
   description:
     'Local developer tool for testing deAPI.ai endpoints. Generate images, videos, audio and more with dynamic forms, async job tracking, and result preview.',
@@ -24,7 +37,6 @@ export const metadata: Metadata = {
     description:
       'Test deAPI.ai endpoints locally with dynamic forms, async job tracking, price calculator and result preview.',
     type: 'website',
-    url: 'https://github.com/deapi-ai/deapi-tester',
     siteName: 'deAPI Tester',
     images: ['/og-image.png'],
   },