> For the complete documentation index, see [llms.txt](https://docs.unskript.com/unskript-documentation/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.unskript.com/unskript-documentation/runbooks/xrunbooks/create-a-parameter.md).

# Create a RunBook Input Parameter

Parameters are the input key:value pairs that can be submitted with your xRunBook in order to run. Let's walk through the steps to create a Parameter for your xRunBook.

## Add Parameter

In this step we will define the key for an input (in the example below, we create a `customer` input key).  You can imagine that you might run a xRunBook with the key:value pair `customer: John Doe.`

{% hint style="info" %}
As a best practice, use snake case for parameter names.
{% endhint %}

To add a parameter to your xRunBook, click the Parameters button to reveal the drop down. 

![Adding a \`customer\` input parameter.](https://491011674-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fm4p7lGuBAXN5jCVyoF7P%2Fuploads%2FFRBquzoxxgWxRV3Nwgus%2FScreen%20Shot%202022-05-16%20at%2012.48.07%20AM.png?alt=media\&token=4226df58-d6bc-4e61-95c2-e08ab36627db)

Fill in the required information and click `CREATE`. Once created, the parameter is available to be used as a Python variable of the same name. You can use this in code for custom Actions that you create, or as arguments to the Actions you are using.

{% embed url="<https://youtu.be/08L2CpWGWdg>" %}
Example of adding an input parameter to a RunBook and Reusing it in Actions.
{% endembed %}

## Input Types

* string
* number
* boolean
* array
* object
* secret (string obfuscated with \*)