This document talks about the implementation of the code for the Api. Everything comes under namespace Razorpay\Api\. Namespaces put a requirement of PHP 5.3 minimum ```php namespace Razorpay\ class Api { // Contains a __get function that returns the appropriate // class object when one tries to access them. } namespace Razorpay\ class Client { // Handles request and response // Uses Composer:Requests internally } class Payment { public function get($id) { } public function fetch($options) { } public function capture($id) { } public function refund($id) { } } ```