Composer is a tool that manages the dependencies of our PHP project. Thanks to this tool, we can work with the installation of libraries that our project needs in a comfortable way, avoiding all the problems that involve installing the dependencies manually and without any control or supervision.
The dependencies are installed in a directory (default called /seller). What if my bookstores depend on others? It is also able to solve that and download everything necessary for it to work and thus avoid doing so manually.
See https://getcomposer.org/ for more information and documentation.
Download and install Composer by following the official instructions.
For usage, see the documentation.
Find packages on Packagist. For install and use GuzzleHttp, see the documentation.
PHP 5.3.2 or above (at least 5.3.4 recommended to avoid potential bugs)