Vercel deploy

Vercel Deployment Skill

Expert deployment of Next.js applications to Vercel with optimal build settings, environment configuration, and custom domain setup.

Quick Reference

Task	File/Command
Configure build	vercel.json
Set env vars	Vercel Dashboard or CLI
Deploy	vercel --prod
Check status	vercel inspect
Custom domain	Vercel Dashboard > Settings > Domains

Project Structure

project/
├── vercel.json              # Vercel configuration
├── next.config.js           # Next.js configuration
├── .env.local               # Local development (not committed)
├── .env.example             # Template (committed)
├── docs/
│   └── deployment.md        # Deployment documentation
└── frontend/                # Next.js app
    ├── app/
    ├── public/
    └── src/

vercel.json Configuration

Basic Configuration

{
  "buildCommand": "npm run build",
  "outputDirectory": ".next",
  "installCommand": "npm install",
  "framework": "nextjs",
  "regions": ["iad1"],
  "env": {
    "NEXT_PUBLIC_API_URL": "@api_url"
  }
}

Advanced Configuration with Rewrites

{
  "version": 2,
  "buildCommand": "npm run build",
  "outputDirectory": ".next",
  "installCommand": "npm install",
  "framework": "nextjs",
  "regions": ["iad1"],

  "rewrites": [
    {
      "source": "/api/:path*",
      "destination": "https://api.yourdomain.com/:path*"
    }
  ],

  "headers": [
    {
      "source": "/(.*)",
      "headers": [
        {
          "key": "X-Content-Type-Options",
          "value": "nosniff"
        },
        {
          "key": "X-Frame-Options",
          "value": "DENY"
        },
        {
          "key": "X-XSS-Protection",
          "value": "1; mode=block"
        }
      ]
    },
    {
      "source": "/static/:path*",
      "headers": [
        {
          "key": "Cache-Control",
          "value": "public, max-age=31536000, immutable"
        }
      ]
    },
    {
      "source": "/api/:path*",
      "headers": [
        {
          "key": "Access-Control-Allow-Origin",
          "value": "*"
        }
      ]
    }
  ],

  "redirects": [
    {
      "source": "/old-path/:path*",
      "destination": "/new-path/:path*",
      "permanent": true
    },
    {
      "source": "/www/:path*",
      "destination": "/:path*",
      "permanent": true
    }
  ]
}

Next.js Config Integration

// next.config.js
/** @type {import('next').NextConfig} */
const nextConfig = {
  // Output configuration for Vercel
  output: 'standalone',

  // Image optimization
  images: {
    remotePatterns: [
      {
        protocol: 'https',
        hostname: 'api.yourdomain.com',
        pathname: '/uploads/**',
      },
    ],
    formats: ['image/avif', 'image/webp'],
  },

  // Headers for security
  async headers() {
    return [
      {
        source: '/:path*',
        headers: [
          {
            key: 'X-DNS-Prefetch-Control',
            value: 'on',
          },
          {
            key: 'Referrer-Policy',
            value: 'origin-when-cross-origin',
          },
        ],
      },
    ];
  },

  // Redirects
  async redirects() {
    return [
      {
        source: '/legacy/:path*',
        destination: '/:path*',
        permanent: true,
      },
    ];
  },

  // Experimental features
  experimental: {
    serverActions: {
      allowedOrigins: ['yourdomain.com'],
    },
  },
};

module.exports = nextConfig;

Environment Variables

Variable Naming Convention

Prefix	Access	Description
NEXT_PUBLIC_	Client + Server	Exposed to browser
No prefix	Server only	Backend/API use only

Required Variables

# .env.example - Copy to .env.local for local dev

# API Configuration
# Backend API URL (development)
NEXT_PUBLIC_API_URL="http://localhost:8000/api/v1"

# Authentication
NEXT_PUBLIC_AUTH_ENABLED="true"

# Feature Flags
NEXT_PUBLIC_ENABLE_DARK_MODE="true"
NEXT_PUBLIC_SHOW_BETA_FEATURES="false"

Production Variables (Set in Vercel Dashboard)

# Environment variables for Production

# API Configuration
NEXT_PUBLIC_API_URL="https://api.yourdomain.com"

# Optional: Analytics
NEXT_PUBLIC_GA_ID="G-XXXXXXXXXX"
NEXT_PUBLIC_POSTHOG_KEY="phc_xxx"

# Optional: Error tracking
NEXT_PUBLIC_SENTRY_DSN="https://[email protected]/xxx"

Sensitive Variables (Server-Only)

These should NOT have NEXT_PUBLIC_ prefix:

# Server-only (never exposed to client)
API_SECRET_KEY="vercel-secret-key"
DATABASE_URL="postgresql://..."
REDIS_URL="redis://..."

Vercel CLI Deployment

Installation and Login

# Install Vercel CLI
npm i -g vercel

# Login to Vercel
vercel login

# Link to project
cd frontend
vercel link

Deployment Commands

# Deploy to preview (staging)
vercel

# Deploy to production
vercel --prod

# Deploy with environment
vercel --env=NODE_ENV=production

# Pull environment variables from Vercel
vercel env pull .env.local

CI/CD Deployment

# In CI pipeline
npm i -g vercel
vercel --token=$VERCEL_TOKEN --yes

Custom Domain Setup

Adding Domain in Vercel

1. Go to Vercel Dashboard > Project > Settings > Domains
2. Add your domain (e.g., yourdomain.com)
3. Configure DNS records

DNS Configuration

# For root domain (yourdomain.com)
Type: A
Name: @
Value: 76.76.21.21

# For www subdomain
Type: CNAME
Name: www
Value: cname.vercel-dns.com.

# For API subdomain (optional)
Type: CNAME
Name: api
Value: cname.vercel-dns.com.

www to Root Redirect

{
  "redirects": [
    {
      "source": "/:path*",
      "destination": "https://yourdomain.com/:path*",
      "permanent": true
    }
  ]
}

API Proxy Setup

Option 1: Vercel Rewrites (Recommended)

{
  "rewrites": [
    {
      "source": "/api/:path*",
      "destination": "https://api.yourdomain.com/:path*"
    }
  ]
}

Option 2: Next.js Rewrite

// next.config.js
async rewrites() {
  return [
    {
      source: '/api/:path*',
      destination: `${process.env.NEXT_PUBLIC_API_URL}/:path*`,
    },
  ];
}

Edge Function for API (Advanced)

// frontend/app/api/[...route]/route.ts
import { NextRequest, NextResponse } from 'next/server';

export async function GET(request: NextRequest) {
  const response = await fetch(
    `${process.env.NEXT_PUBLIC_API_URL}/api/v1/endpoint`,
    {
      headers: {
        'Authorization': request.headers.get('Authorization') || '',
        'Content-Type': 'application/json',
      },
    }
  );

  const data = await response.json();
  return NextResponse.json(data);
}

Build Optimization

Build Command

# Standard build
npm run build

# With TypeScript check only
npm run build -- --no-lint

# Custom build
next build

Performance Settings

// next.config.js
const nextConfig = {
  // Enable SWC minifier (faster builds)
  swcMinify: true,

  // Compiler options
  compiler: {
    removeConsole: process.env.NODE_ENV === 'production',
  },

  // Image optimization
  images: {
    deviceSizes: [640, 750, 828, 1080, 1200, 1920, 2048, 3840],
    imageSizes: [16, 32, 48, 64, 96, 128, 256, 384],
  },

  // Enable react strict mode
  reactStrictMode: true,

  // Generate Etag
  generateEtags: true,
};

Bundle Analysis

# Install bundle analyzer
npm install -D @next/bundle-analyzer

# next.config.js
const withBundleAnalyzer = require('@next/bundle-analyzer')({
  enabled: process.env.ANALYZE === 'true',
});

module.exports = withBundleAnalyzer({
  // your config
});

Error Pages

Custom 404 Page

// frontend/app/not-found.tsx
import Link from 'next/link';

export default function NotFound() {
  return (
    <div className="min-h-screen flex flex-col items-center justify-center">
      <h1 className="text-4xl font-bold">404 - Page Not Found</h1>
      <p className="mt-2 text-gray-600">
        The page you're looking for doesn't exist.
      </p>
      <Link
        href="/"
        className="mt-4 px-4 py-2 bg-blue-600 text-white rounded"
      >
        Go Home
      </Link>
    </div>
  );
}

Custom 500 Page

// frontend/app/error.tsx
'use client';

export default function Error({
  error,
  reset,
}: {
  error: Error & { digest?: string };
  reset: () => void;
}) {
  return (
    <div className="min-h-screen flex flex-col items-center justify-center">
      <h1 className="text-4xl font-bold">Something went wrong!</h1>
      <p className="mt-2 text-gray-600">
        An unexpected error occurred.
      </p>
      <button
        onClick={() => reset()}
        className="mt-4 px-4 py-2 bg-blue-600 text-white rounded"
      >
        Try Again
      </button>
    </div>
  );
}

Global Error Boundary

// frontend/app/global-error.tsx
'use client';

export default function GlobalError({
  error,
}: {
  error: Error & { digest?: string };
}) {
  return (
    <html>
      <body>
        <div className="min-h-screen flex items-center justify-center">
          <h1 className="text-2xl">Application Error</h1>
        </div>
      </body>
    </html>
  );
}

Deployment Checklist

• Build succeeds locally: npm run build completes without errors
• Build succeeds on Vercel: Deploy preview builds correctly
• Correct API URLs: NEXT_PUBLIC_API_URL points to correct environment
• No sensitive vars exposed: No NEXT_PUBLIC_ prefix on secrets
• 404 page configured: Custom not-found.tsx exists
• 500 page configured: Custom error.tsx exists
• Custom domain set up: DNS records configured correctly
• HTTPS enforced: Automatic SSL certificate
• Redirects configured: www to root or vice versa
• Cache headers set: Static assets properly cached

Deployment Documentation Template

# Deployment Guide

## Quick Deploy

[![Deploy with Vercel](https://vercel.com/button)](https://vercel.com/new)

## Environment Variables

### Development
```bash
NEXT_PUBLIC_API_URL=http://localhost:8000/api/v1

Production

NEXT_PUBLIC_API_URL=https://api.yourdomain.com

Custom Domain

1. Add yourdomain.com in Vercel Dashboard > Settings > Domains
2. Configure DNS:
   • A record: @ -> 76.76.21.21
   • CNAME: www -> cname.vercel-dns.com

Troubleshooting

Build Fails

# Run locally to see error
npm run build

Environment Variables Not Working

• Check variable name starts with NEXT_PUBLIC_ for client access
• Redeploy after adding new variables

404 on Production

• Verify vercel.json outputDirectory matches build output
• Check page files are in app/ directory (App Router)

## Integration Points

| Skill | Integration |
|-------|-------------|
| `@frontend-nextjs-app-router` | Next.js App Router configuration |
| `@env-config` | Environment variable management |
| `@tailwind-css` | CSS build optimization |
| `@api-route-design` | API routes and rewrites |
| `@error-handling` | Custom error pages |