Vercel Hello World

Vercel Hello World

Overview

Deploy a minimal project to Vercel with a static page and a serverless API route. Confirms your CLI auth, project structure, and deployment pipeline work end to end.

Prerequisites

• Completed vercel-install-auth setup
• Vercel CLI installed and authenticated
• Node.js 18+

Instructions

Step 1: Create Project Structure

mkdir my-vercel-app && cd my-vercel-app
npm init -y

Create the static landing page:

<!-- public/index.html -->
<!DOCTYPE html>
<html>
<head><title>Hello Vercel</title></head>
<body>
  <h1>Hello from Vercel</h1>
  <p id="result">Loading...</p>
  <script>
    fetch('/api/hello')
      .then(r => r.json())
      .then(d => document.getElementById('result').textContent = d.message);
  </script>
</body>
</html>

Step 2: Create Serverless API Route

// api/hello.ts
import type { VercelRequest, VercelResponse } from '@vercel/node';

export default function handler(req: VercelRequest, res: VercelResponse) {
  res.status(200).json({
    message: 'Hello from Vercel Serverless Function!',
    timestamp: new Date().toISOString(),
    region: process.env.VERCEL_REGION || 'local',
  });
}

Install the types:

npm install --save-dev @vercel/node typescript

Step 3: Add vercel.json Configuration

{
  "rewrites": [
    { "source": "/api/(.*)", "destination": "/api/$1" }
  ],
  "headers": [
    {
      "source": "/api/(.*)",
      "headers": [
        { "key": "Cache-Control", "value": "s-maxage=0, stale-while-revalidate" }
      ]
    }
  ]
}

Step 4: Deploy Preview

# Deploy to a preview URL (not production)
vercel

# Output:
# Vercel CLI 39.x.x
# 🔗 Linked to your-team/my-vercel-app
# 🔍 Inspect: https://vercel.com/your-team/my-vercel-app/xxx
# ✅ Preview: https://my-vercel-app-xxx.vercel.app

Step 5: Test the Deployment

# Test static page
curl -s https://my-vercel-app-xxx.vercel.app/ | head -5

# Test API route
curl -s https://my-vercel-app-xxx.vercel.app/api/hello | jq .
# {
#   "message": "Hello from Vercel Serverless Function!",
#   "timestamp": "2026-03-22T12:00:00.000Z",
#   "region": "iad1"
# }

Step 6: Promote to Production

# Deploy directly to production
vercel --prod

# Or promote the preview deployment
vercel promote https://my-vercel-app-xxx.vercel.app

Vercel System Environment Variables

These are available in every function at runtime:

Output

• Static page served from Vercel CDN
• Serverless API route returning JSON at /api/hello
• Preview URL for testing before production
• Production deployment live on your domain

Error Handling

Examples

Deploy a harmless preview before connecting a domain

Create a minimal route that returns a static health response and deploy it with vercel --yes from a feature branch. Test the generated preview URL, verify the commit SHA in the deployment metadata, and keep environment variables absent unless the example requires them. Only after the preview is healthy should a reviewer approve the production workflow; do not point a customer domain at an unreviewed hello-world deployment.

Resources

• Vercel Serverless Functions
• Vercel Project Configuration
• Vercel CLI Deploy
• @vercel/node Runtime

Next Steps

Proceed to vercel-local-dev-loop for development workflow setup.