Craft 3 Composer Install Valet Driver

Craft3ValetDriver.php

<?php

class Craft3ValetDriver extends ValetDriver
/* https://github.com/laravel/valet/blob/master/cli/drivers/CraftValetDriver.php */
{
    /**
     * Determine if the driver serves the request.
     *
     * @param  string  $sitePath
     * @param  string  $siteName
     * @param  string  $uri
     * @return bool
     */
    public function serves($sitePath, $siteName, $uri)
    {
      return is_dir($sitePath.'/vendor/craftcms/cms');
    }

    /**
     * Determine if the incoming request is for a static file.
     *
     * @param  string  $sitePath
     * @param  string  $siteName
     * @param  string  $uri
     * @return string|false
     */
    public function isStaticFile($sitePath, $siteName, $uri)
    {
        if (file_exists($staticFilePath = $sitePath.'/web/'.$uri)) {
            return $staticFilePath;
        }

        return false;
    }

    /**
     * Get the fully resolved path to the application's front controller.
     *
     * @param  string  $sitePath
     * @param  string  $siteName
     * @param  string  $uri
     * @return string
     */
    public function frontControllerPath($sitePath, $siteName, $uri)
    {
        $_SERVER['SCRIPT_FILENAME'] = $sitePath.'/web/index.php';
        $_SERVER['SERVER_NAME'] = $_SERVER['HTTP_HOST'];
        $_SERVER['SCRIPT_NAME'] = '/index.php';
        return $sitePath.'/web/index.php';
    }
}

Just drop this into the following folder > /Users/[your user name]/.valet/Drivers