$embeddedComposer = new EmbeddedComposer(
    $classLoader,
    $projectDir,
    "sculpin/sculpin"
);

<?php

// assume installation via phar:// this is the correct location of the
// embedded autoload.php.
if (!$classLoader = @include __DIR__.'/../vendor/autoload.php') {
    die ('There is something terribly wrong with your archive.
Try downloading again?');
}

use Dflydev\EmbeddedComposer\Core\EmbeddedComposer;
use Sculpin\Bundle\SculpinBundle\Console\Application;
use Sculpin\Bundle\SculpinBundle\HttpKernel\KernelFactory;
use Symfony\Component\Console\Input\ArgvInput;

$input = new ArgvInput;

$projectDir = $input->getParameterOption('--project-dir') ?: null;

$embeddedComposer = new EmbeddedComposer($classLoader, $projectDir);

// one can optionally configure embedded composer to read from
// a composer.json named something different and default to
// another vendor directory.
$embeddedComposer
    ->setComposerFilename('sculpin.json')
    ->setVendorDirectory('.sculpin');

// if actually embedded in a phar or installed globally, this will
// process the local project's autoloader. otherwise, this is a
// noop. since the same script may operate under either mode
// it should always be called.
$embeddedComposer->processAdditionalAutoloads();

$kernel = KernelFactory::create($input);
$application = new Application($kernel, $embeddedComposer);
$application->run($input);

<?php

namespace Sculpin\Bundle\SculpinBundle\Console;

use Dflydev\EmbeddedComposer\Core\EmbeddedComposerInterface;
use Dflydev\EmbeddedComposer\Core\EmbeddedComposerAwareInterface;
use Symfony\Component\Console\Application as BaseApplication;
use Symfony\Component\HttpKernel\KernelInterface;

class Application extends BaseApplication implements EmbeddedComposerAwareInterface
{
    /**
     * Constructor.
     *
     * @param KernelInterface           $kernel           A KernelInterface instance
     * @param EmbeddedComposerInterface $embeddedComposer Composer Class Loader
     */
    public function __construct(KernelInterface $kernel, EmbeddedComposerInterface $embeddedComposer)
    {
        $this->kernel = $kernel;
        $this->embeddedComposer = $embeddedComposer;

        // leverages this patch, sculpin/sculpin is the root package that creates the phar
        // and needs to be in the installed.json in order to work.
        $version = $embeddedComposer->findPackage('sculpin/sculpin')->getPrettyVersion();
        if ($version !== Sculpin::GIT_VERSION && Sculpin::GIT_VERSION !== '@'.'git_version'.'@') {
            $version .= ' ('.Sculpin::GIT_VERSION.')';
        }

        parent::__construct('Sculpin', $version.' - '.$kernel->getName().'/'.$kernel->getEnvironment().($kernel->isDebug() ? '/debug' : ''));

        // ...
    }

    /** ... */
}

<?php
class InstallCommand extends Command
{
    protected function configure()
    {
        $this
            ->setName('composer:install')
            ->setDescription('Parses the composer.json file and downloads the needed dependencies.')
            ->setDefinition(array(
                new InputOption('prefer-source', null, InputOption::VALUE_NONE, 'Forces installation from package sources when possible, including VCS information.'),
                new InputOption('dry-run', null, InputOption::VALUE_NONE, 'Outputs the operations but will not execute anything (implicitly enables --verbose).'),
                new InputOption('dev', null, InputOption::VALUE_NONE, 'Enables installation of dev-require packages.'),
                new InputOption('no-scripts', null, InputOption::VALUE_NONE, 'Skips the execution of all scripts defined in composer.json file.'),
            ))
            ->setHelp(<<<EOT
The <info>install</info> command reads the composer.json file from the
current directory, processes it, and downloads and installs all the
libraries and dependencies outlined in that file.

<info>php composer.phar install</info>

EOT
            );
    }

    protected function execute(InputInterface $input, OutputInterface $output)
    {
        if (!$this->getApplication() instanceof EmbeddedComposerAwareInterface) {
            throw new \RuntimeException('Application must be instance of EmbeddedComposerAwareInterface');
        }

        $embeddedComposer = $this->getApplication()->getEmbeddedComposer();

        $io = new ConsoleIO($input, $output, $this->getApplication()->getHelperSet());
        // Create a Composer instance that is aware of its embedded environment
        $composer = $embeddedComposer->createComposer($io);
        $installer = Installer::create($io, $composer);

        $installer
            ->setDryRun($input->getOption('dry-run'))
            ->setVerbose($input->getOption('verbose'))
            ->setPreferSource($input->getOption('prefer-source'))
            ->setDevMode($input->getOption('dev'))
            ->setRunScripts(!$input->getOption('no-scripts'));

        // perform any additional configuration on the installer
        // instance. for example, set an additional installed
        // repository in the case that the script is running
        // in an embedded environment.
        $embeddedComposer->configureInstaller($installer);

        return $installer->run() ? 0 : 1;
    }
}
?>