Deploying Laravel 11/12 to Vercel with Neon PostgreSQL: A Complete Guide

Introduction

Deploying a Laravel application to a serverless platform like Vercel presents unique challenges, particularly when integrating with cloud databases such as Neon PostgreSQL. This guide documents the complete deployment process, common pitfalls I encountered, and their solutions to help you avoid the same mistakes.

Technology Stack

Core Technologies

  • Laravel Framework: v12.31.1
  • PHP: 8.3.16
  • Vercel: Serverless deployment platform
  • Neon PostgreSQL: Serverless PostgreSQL database
  • Vercel PHP Runtime: v0.7.4

Additional Packages

  • Laravel Pint: v1 - Code style fixer
  • Pest: v4 - Testing framework
  • Alpine.js: v3 - Frontend reactivity
  • Tailwind CSS: v4 - Styling framework

Architecture Overview

Serverless Constraints

Vercel’s serverless environment imposes several important constraints that must be addressed:

  1. Read-only filesystem: Only /tmp directory is writable
  2. Stateless execution: Each request may run on a different instance
  3. Cold starts: First request may experience latency
  4. No persistent storage: File uploads must use external storage (S3, etc.)

Project Structure

your-laravel-app/
├── api/
│   └── index.php          # Vercel entry point
├── config/
│   └── database.php       # Database configuration
├── public/
│   └── index.php          # Laravel entry point
├── vercel.json            # Vercel configuration
└── .env                   # Environment variables (local)

Configuration Setup

1. Vercel Configuration (vercel.json)

Create a minimal vercel.json file:

{
    "version": 2,
    "framework": null,
    "functions": {
        "api/index.php": {
            "runtime": "vercel-php@0.7.4"
        }
    },
    "routes": [
        {
            "src": "/build/assets/(.*)",
            "dest": "/public/build/assets/$1"
        },
        {
            "src": "/images/(.*)",
            "dest": "/public/images/$1"
        },
        {
            "src": "/(.*)",
            "dest": "/api/index.php"
        }
    ]
}

Important: Do not hardcode environment variables in vercel.json. Use Vercel’s environment variable system instead.

2. API Entry Point (api/index.php)

<?php

// Ensure /tmp directories exist for Vercel serverless
$tmpDirs = ['/tmp/views', '/tmp/cache', '/tmp/sessions'];
foreach ($tmpDirs as $dir) {
    if (!is_dir($dir)) {
        @mkdir($dir, 0755, true);
    }
}

// Forward Vercel requests to normal index.php
require __DIR__ . '/../public/index.php';

3. Database Configuration

Update config/database.php for the PostgreSQL connection:

'pgsql' => [
    'driver' => 'pgsql',
    'host' => env('DB_HOST', '127.0.0.1'),
    'port' => env('DB_PORT', '5432'),
    'database' => env('DB_DATABASE', 'laravel'),
    'username' => env('DB_USERNAME', 'root'),
    'password' => env('DB_PASSWORD', ''),
    'charset' => 'utf8',
    'prefix' => '',
    'prefix_indexes' => true,
    'search_path' => 'public',
    'sslmode' => 'require',
],

4. Force HTTPS in Production

Update app/Providers/AppServiceProvider.php:

<?php

namespace App\Providers;

use Illuminate\Support\Facades\URL;
use Illuminate\Support\ServiceProvider;

class AppServiceProvider extends ServiceProvider
{
    public function boot(): void
    {
        if (config('app.env') !== 'local') {
            URL::forceScheme('https');
        }
    }
}

Neon PostgreSQL Integration

Connection Configuration

Neon PostgreSQL requires specific connection parameters due to its serverless architecture. The connection string format is:

postgresql://[user]:[password]@[endpoint]-pooler.[region].aws.neon.tech/[database]?sslmode=require

Critical Environment Variables

Set these in Vercel using the CLI (without newlines):

echo -n "your-endpoint-pooler.region.aws.neon.tech" | vercel env add DB_HOST production
echo -n "5432" | vercel env add DB_PORT production
echo -n "your-database-name" | vercel env add DB_DATABASE production
echo -n "your-username" | vercel env add DB_USERNAME production
echo -n "your-password" | vercel env add DB_PASSWORD production

Additional Required Environment Variables

# Laravel cache paths (must use /tmp for serverless)
echo -n "production" | vercel env add APP_ENV production
echo -n "/tmp/config.php" | vercel env add APP_CONFIG_CACHE production
echo -n "/tmp/events.php" | vercel env add APP_EVENTS_CACHE production
echo -n "/tmp/packages.php" | vercel env add APP_PACKAGES_CACHE production
echo -n "/tmp/routes.php" | vercel env add APP_ROUTES_CACHE production
echo -n "/tmp/services.php" | vercel env add APP_SERVICES_CACHE production
echo -n "/tmp/views" | vercel env add VIEW_COMPILED_PATH production

# Serverless-friendly drivers
echo -n "array" | vercel env add CACHE_DRIVER production
echo -n "stderr" | vercel env add LOG_CHANNEL production
echo -n "cookie" | vercel env add SESSION_DRIVER production
echo -n "false" | vercel env add APP_DEBUG production

Common Issues and Solutions

Issue 1: Newline Characters in Environment Variables

Problem: Using echo without -n flag adds newline characters to environment variables.

Symptom:

ERROR: password authentication failed for user 'neondb_owner\n'

Solution: Always use echo -n when piping to vercel env add:

echo -n "value" | vercel env add VAR_NAME production

Issue 2: Invalid SSL Mode

Problem: DATABASE_URL parsing adds underscore to sslmode.

Symptom:

SQLSTATE[08006] [7] invalid sslmode value: "require_"

Solution: Use individual connection parameters instead of DATABASE_URL, and hardcode sslmode in config/database.php:

'sslmode' => 'require',

Issue 3: Cache Path Issues

Problem: Attempting to write to read-only filesystem.

Symptom:

InvalidArgumentException: Please provide a valid cache path.

Solution:

  1. Create /tmp directories in api/index.php
  2. Configure all cache paths to use /tmp directory

Issue 4: Database Session Driver Not Working

Problem: Serverless environment doesn’t support database sessions reliably.

Solution: Use cookie-based sessions in production:

echo -n "cookie" | vercel env add SESSION_DRIVER production

Deployment Process

Step 1: Prepare Local Environment

# Ensure Vercel CLI is installed
npm i -g vercel

# Login to Vercel
vercel login

Step 2: Configure Environment Variables

Run all the environment variable commands listed above.

Step 3: Deploy

# Deploy to production
vercel --prod

Step 4: Verify Deployment

Visit your deployment URL and verify:

  • Homepage loads correctly
  • Database connection works
  • Static assets load properly
  • SSL is enforced

Performance Optimization

Database Connection Pooling

Always use the pooled connection endpoint from Neon:

[endpoint]-pooler.[region].aws.neon.tech

Caching Strategy

Due to serverless constraints:

  • Use array cache driver (ephemeral, request-scoped)
  • Consider external caching solutions (Redis, Memcached) for persistent cache
  • Avoid database cache driver

Asset Optimization

# Build assets before deployment
npm run build

# Ensure assets are accessible via proper routes in vercel.json

Security Considerations

Environment Variables

  1. Never commit .env files
  2. Use Vercel’s encrypted environment variables
  3. Rotate database credentials regularly
  4. Use different credentials for staging/production

Database Security

  1. Enable SSL mode: sslmode=require
  2. Use IP allowlisting when possible
  3. Follow principle of least privilege for database users
  4. Regular security audits

Application Security

  1. Disable debug mode in production: APP_DEBUG=false
  2. Set secure session configuration
  3. Enable CSRF protection
  4. Use HTTPS exclusively

Monitoring and Debugging

Enable Debug Mode Temporarily

echo -n "true" | vercel env add APP_DEBUG production
vercel --prod

View Logs

vercel logs [deployment-url]

Common Debug Routes

Create temporary debug routes for troubleshooting:

Route::get('/debug', function () {
    try {
        \Illuminate\Support\Facades\DB::connection()->getPdo();
        $dbConnected = true;
        $dbError = null;
    } catch (\Exception $e) {
        $dbConnected = false;
        $dbError = $e->getMessage();
    }

    return response()->json([
        'database_connected' => $dbConnected,
        'database_error' => $dbError,
        'env_check' => [
            'DB_HOST' => env('DB_HOST') ? 'set' : 'not set',
            'DB_DATABASE' => env('DB_DATABASE') ? 'set' : 'not set',
        ],
    ]);
});

Migration Strategy

Running Migrations

Since Vercel is serverless, run migrations separately:

# Pull production environment variables
vercel env pull .env.production.local

# Run migrations with production config
php artisan migrate --env=production --force

Database Seeding

php artisan db:seed --env=production --force

Best Practices

1. Separation of Concerns

  • Keep serverless configuration separate from application logic
  • Use environment-specific configurations
  • Maintain separate .env files for different environments

2. Error Handling

  • Implement comprehensive error logging
  • Use Laravel’s exception handler
  • Monitor Vercel deployment logs

3. Testing Strategy

  • Test locally with production-like environment
  • Use staging deployments for verification
  • Implement automated testing (Pest/PHPUnit)

4. Version Control

  • .gitignore sensitive files
  • Document deployment process
  • Tag production releases

Troubleshooting Checklist

When deployment fails, verify:

  • All environment variables are set correctly (no trailing newlines)
  • Database credentials are accurate
  • SSL mode is configured properly
  • /tmp directories are created in api/index.php
  • Cache paths point to /tmp directory
  • Debug mode is enabled for troubleshooting
  • Vercel function timeout is sufficient
  • Database migrations have been run
  • Static assets are built and accessible

Conclusion

Deploying Laravel to Vercel with Neon PostgreSQL requires careful attention to serverless constraints and proper configuration. The key challenges revolve around:

  1. Filesystem limitations: Using /tmp for all writable operations
  2. Database connectivity: Proper SSL configuration and connection parameters
  3. Environment variables: Avoiding newline characters and proper formatting
  4. Stateless execution: Using appropriate session and cache drivers

By following this guide and addressing the common issues documented here, you can successfully deploy and maintain a Laravel application on Vercel’s serverless platform with Neon PostgreSQL as the database backend.

Additional Resources

Author: Bilell Ghersa Last Updated: October 2025 Laravel Version: 12.31.1 PHP Version: 8.3.16