php composer.phar require coderockr/silex-mongodb-provider

<?php

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

use Silex\Application;
use Coderockr\Mongodb\ServiceProvider as MongodbServiceProvider;

$app = new Application();
$app->register(new MongodbServiceProvider(), [
    'mongodb.options' => [
        'uri' => 'mongodb://localhost:27017'
    ]
]);

$manager = $app['mongodb']; // or $app['mongodbs']['default'];
$collection = new MongoDB\Collection($manager, "demo.beers");
$result = $collection->insertOne(['name' => 'Hinterland', 'brewery' => 'BrewDog']);

echo "Inserted with Object ID '{$result->getInsertedId()}'";