composer require ggdx/php-insightly
$insightly = new Insightly($api_key, $api_version) // $api_version is optional, v2.2 is default
$insightly->getContacts();
Documentation will follow but for now, all methods are fully documented in the code.
For $data arrays, please see Insightly API Docs for requirements. For the most part, Insightly is pretty flexible with "required" data but there are certain situations where a minimum dataset is required.
For the Laravel 5 service provider, look here