Using Composer on DirectAdmin Hosting to Install PHP Packages

Composer is the de facto dependency manager for PHP. It lets you install and manage libraries like PHPMailer, Guzzle, Carbon, and Stripe SDK with a single command. On DirectAdmin Shared Hosting with SSH access, you can run Composer directly in the terminal — or install packages locally and upload the vendor/ folder via FTP if SSH isn't available.

Verify PHP CLI and SSH Access

Composer requires PHP CLI (Command Line). Check it via SSH:

ssh [email protected]
php -v
# PHP 8.3.x (cli)

If the default PHP version isn't what you need, use the versioned binary that DirectAdmin provides:

php83 -v

Install Composer on Hosting

cd ~
curl -sS https://getcomposer.org/installer | php
# Creates composer.phar in the current directory

Add an alias so you can type composer instead of php composer.phar:

echo 'alias composer="php ~/composer.phar"' >> ~/.bashrc
source ~/.bashrc
composer --version

Create a PHP Project with Composer

composer.json (basic structure)

{
  "require": {
    "phpmailer/phpmailer": "^6.9",
    "guzzlehttp/guzzle": "^7.8",
    "nesbot/carbon": "^3.0"
  }
}

Install Packages

cd ~/domains/yourdomain.com/public_html
composer install

Composer creates a vendor/ directory containing all packages and the vendor/autoload.php file.

Understanding the Files Composer Creates

After a successful composer install, your project directory will contain several important files and folders:

The composer.lock file is critical for teams and production deployments. It guarantees every composer install installs the exact same package versions, preventing the "works on my machine" problem caused by version drift between developers and the server.

Managing Dependencies Like a Pro

Choosing the Right Version Constraint

How you write version constraints in composer.json significantly affects your project's stability and security update coverage:

Autoloading Your Own Project Classes

Beyond loading package classes, Composer can also autoload your own application classes using PSR-4 namespacing:

{
  "require": {
    "phpmailer/phpmailer": "^6.9"
  },
  "autoload": {
    "psr-4": {
      "App\\": "src/"
    }
  }
}

After adding the autoload section, run composer dump-autoload to regenerate the autoloader. Any class in the src/ directory under the App\ namespace will then be loaded automatically.

Use Packages in PHP Code

format('d/m/Y H:i');

// PHPMailer example
$mail = new PHPMailer(true);
$mail->isSMTP();
$mail->Host = 'smtp.yourdomain.com';
// ... send email

Popular Packages and Real-World Usage Examples

Stripe PHP SDK — Accept Online Payments

The Stripe SDK enables your PHP project to accept credit card payments, PromptPay, and QR Code payments with minimal code.

composer require stripe/stripe-php

require_once __DIR__ . '/vendor/autoload.php';

\Stripe\Stripe::setApiKey('sk_live_xxx');

$intent = \Stripe\PaymentIntent::create([
  'amount'   => 50000, // amount in smallest currency unit (satang for THB)
  'currency' => 'thb',
]);
echo $intent->client_secret;

Guzzle HTTP Client — Make API Requests

Guzzle is the go-to HTTP client for PHP, offering async requests, middleware support, and automatic retries out of the box.

composer require guzzlehttp/guzzle

use GuzzleHttp\Client;

$client = new Client(['base_uri' => 'https://api.example.com']);
$response = $client->get('/users', [
  'headers' => ['Authorization' => 'Bearer token123'],
  'timeout' => 5,
]);
$data = json_decode($response->getBody(), true);

Carbon — Work with Dates and Times

Carbon extends PHP's native DateTime class with a fluent API for formatting, timezone conversion, localization, and human-readable diffs.

composer require nesbot/carbon

use Carbon\Carbon;
Carbon::setLocale('en');

$now = Carbon::now('Asia/Bangkok');
echo $now->format('d/m/Y H:i');       // 07/06/2026 15:30
echo $now->diffForHumans();            // just now
echo $now->addDays(7)->toDateString(); // 2026-06-14

Intervention Image — Resize and Convert Images

Intervention Image handles resizing, cropping, watermarking, and format conversion (WebP, JPG, PNG) directly from PHP — no shell commands needed.

composer require intervention/image

use Intervention\Image\ImageManager;
use Intervention\Image\Drivers\Gd\Driver;

$manager = new ImageManager(new Driver());
$image = $manager->read('upload.jpg');
$image->resize(width: 820, height: 340);
$image->save('output.webp'); // automatically converts to WebP

No SSH? Upload vendor/ via FTP

If SSH isn't available on your plan, install Composer locally then upload the vendor/ folder via FTP:

1. Install Composer locally (Mac: brew install composer / Windows: download installer)
2. Run composer install in your project folder
3. Upload the vendor/ directory and composer.lock to Hosting via FileZilla or FTP

Common Composer Commands

# Install all dependencies from composer.json
composer install

# Add a new package
composer require stripe/stripe-php

# Update all packages to latest allowed versions
composer update

# Update a specific package
composer update phpmailer/phpmailer

# Remove a package
composer remove guzzlehttp/guzzle

# List installed packages
composer show

Security Best Practices for Composer in Production

Running Composer on a live hosting environment requires extra attention to security. Follow these practices to keep your project protected:

• Block web access to vendor/ — Create a vendor/.htaccess file containing Deny from all. This prevents anyone from directly accessing your installed package source code via a browser.
• Run composer audit regularly — This command checks your installed packages against a database of known security vulnerabilities (CVEs) and warns you if any package needs updating.
• Skip dev dependencies in production — Run composer install --no-dev --optimize-autoloader to avoid installing testing and debugging tools on your live server.
• Validate your composer.json — Run composer validate before deploying to catch JSON syntax errors or invalid constraint formats that might cause install failures.

# Audit installed packages for known vulnerabilities
composer audit

# Install production-only dependencies with optimized autoloader
composer install --no-dev --optimize-autoloader

# Validate your composer.json before deployment
composer validate

Common Issues on Shared Hosting

Memory limit exceeded

php -d memory_limit=512M composer.phar install

Need a specific PHP version

php83 ~/composer.phar install

SSH session times out

Use nohup to keep Composer running after SSH disconnects:

nohup php ~/composer.phar install > composer.log 2>&1 &