> For the complete documentation index, see [llms.txt](https://harmonycms.gitbook.io/platform/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://harmonycms.gitbook.io/platform/project/stack.md).

# Stack

## Overview

With a *Stack* we provide an other level of simplicity used by the feature *Project*.\
A *Stack* is a `pile` who can only contain links to public packages (hosted on [Packagist.org](https://packagist.org)) and  private packages (hosted on harmony Marketplace).

By example, if you choose the database *MongoDB* for your project, we will link the stack named **MongoDB**. This stack will tell to HarmonyFlex to execute the command `composer config "platform.ext-mongo" "1.6.16"` and install the next packages:

* [alcaeus/mongo-php-adapter](https://packagist.org/packages/alcaeus/mongo-php-adapter)
* [doctrine/mongodb](https://packagist.org/packages/doctrine/mongodb)
* [doctrine/mongodb-odm-bundle](https://packagist.org/packages/doctrine/mongodb-odm-bundle)