> ## Knowledge Base Index
> Fetch the complete knowledge base index at: https://documentation.celestory.io/sitemap.xml
> Use this file to discover available pages before exploring further.
> Pure-Markdown content can be obtained by appending a '.md' suffix to the content URLs listed in the sitemap (without the trailing slash).

# 🎒 Inventory

Example link: [https://creator.celestory.io/project/WkgOt6qn8](https://creator.celestory.io/project/WkgOt6qn8)

Inventories use List variables. This is a type of variable that can hold multiple values of the same type (boolean, numeric, text or image).

![](https://storage.crisp.chat/users/helpdesk/website/d46a92e92b2b3800/image_16qsmcu.png)

There is no default value to put in this type of variable.

They are very useful to create an inventory or to represent all possible options of a value in a database (Single/multiple select in Airtable).

You can directly add a value to this List by using the block 🟦 Add to a list.

![](https://storage.crisp.chat/users/helpdesk/website/d46a92e92b2b3800/image_143uzlt.png)

The block 🟦 Retrieve from a list allows to retrieve one of the numbered values from the list. Each value has an index number.

Thus, if we retrieve the value in index 1, we will retrieve here the 1st element entered by the user.

![](https://storage.crisp.chat/users/helpdesk/website/d46a92e92b2b3800/image_15idhk2.png)

The block 🟦 List contains allows to check if the list contains a specific value, like different words, and thus different textual values.

Be careful, you have to use a List contains block for each value you want to check.

![](https://storage.crisp.chat/users/helpdesk/website/d46a92e92b2b3800/image_3e78ef.png)