Bootstrap Craft 3 for Psysh

.psysh.php

<?php
/**
 * Craft console bootstrap file
 */

// Set path constants
define('CRAFT_BASE_PATH', __DIR__);
define('CRAFT_VENDOR_PATH', CRAFT_BASE_PATH . '/vendor');

// Load Composer's autoloader
require_once CRAFT_VENDOR_PATH . '/autoload.php';

// Load dotenv?
if (class_exists('Dotenv\Dotenv') && file_exists(CRAFT_BASE_PATH . '/.env')) {
    (new Dotenv\Dotenv(CRAFT_BASE_PATH))->load();
}

// Load and run Craft
define('CRAFT_ENVIRONMENT', getenv('ENVIRONMENT') ?: 'production');
$app = require CRAFT_VENDOR_PATH . '/craftcms/cms/bootstrap/console.php';

return [];