# Variables

Variables are used to store any information the bot knows about a user. This can be their preferred language, or the channel they're using, but also information coming from external data sources like, for example, an API. 

All variables used in a single conversation are stored in what is called a [user session](/bot-answers/session.md).

<figure><img src="/files/MeoOmwTbJ3RaUfy4V9r7" alt=""><figcaption><p>The Variables pageL</p></figcaption></figure>

## Create a variable

To create a variable from the **Variables** page:

1. Click on **Create variable** at the top right corner of the screen.

<figure><img src="/files/XK7BGXjba43yBfisBJEA" alt="" width="375"><figcaption><p>Create a variable from the Variables page</p></figcaption></figure>

2. A window pops up. Fill in the **Name**, **Default value** and **Description**.

{% hint style="info" %}
For example, a default value can be used for URL path ensures the chatbot can always fetch data or interact with external services correctly.
{% endhint %}

{% hint style="danger" %}
Note that default values are:

* Limited to string data types.
* Exported with the bot export. It means that variables along with their default values will be overwritten at import.
* If a variable has a default value on the LIVE version, publishing won't change it. If not, the DRAFT version's default value will be copied to the LIVE version.
* If you use a [Clear session](/buildabot/flow-logic/dialog-state/action-bot-dialog.md#clear-session) action, the value for a variable will be reset to its default value if it had been modified during the session.&#x20;
  {% endhint %}

<figure><img src="/files/GcTQ0eYzXQFKP9Lm281w" alt=""><figcaption><p>Example of a variable with a default value to call an API endpoint.</p></figcaption></figure>

3. Click on **Create variable**.

## Set a variable as sensitive

Chatlayer allows you to make sure that some variables are processed differently. This is useful when the conversation between a bot and a user contains **sensitive information**, such as the user's bank account number or anything GDPR-sensitive.

{% hint style="danger" %}
If you set your variable as sensitive, its value will never be shown in Chatlayer. Instead, users will see a placeholder. The real variable value can only be retrieved through an [API request](https://api.chatlayer.ai/v1/docs/#operation/getAllMessagesInConversation).
{% endhint %}

To define a variable as sensitive:

1. [Create a variable](#create-a-variable) or edit it using the **Edit** button.
2. Toggle on the **Sensitive** switch if you don't want this variable to be saved in the conversation history.
3. Click on **Create variable**.

<figure><img src="/files/3o9Tld9zU1bM6DT4PWXh" alt="" width="375"><figcaption><p>Create a sensitive variable from the Variables page.</p></figcaption></figure>

## Operations on variables

You can perfom operations on your variables.

### Increment

If you want to incrementally increase the value of a variable, you can use the following steps:

1. Define a variable, for example `variableName`, and give it a numeric value such as `0`
2. At the point in the flow where you want to increment the value of `variableName`, enter variableName as the variable and `{variableName|increment}` as the value

This method will increase the value of counter by 1 each time, for example when a specific block is passed or a button is clicked.&#x20;

{% hint style="info" %}
Incrementing a variable can be typically useful when you want to count how many times the user wasn't understood by the bot. Learn how to build a **Not Understood Counter** [here](https://docs.chatlayer.ai/tips-and-best-practices/not-understood-bot-dialog/not-understood-counter).
{% endhint %}

### Change the case

Variables and values are case-sensitive.&#x20;

For example, `capitalVariable` will be regarded as a separate variable from`CapitalVariable`.

The same goes for values. If you check in a [Condition](/buildabot/flow-logic/dialog-state/plugins.md) block if a value for `variableX` is equal to `valueY` it will not be triggered if the value for `variableX` is equal to `valuey`

You can transform a value from upper case to lower case and vice versa by adding these modifiers to the value name:

```
{name|toUpperCase}
{name|toLowerCase}
{name|capitalize}
```

{% hint style="warning" %}
Note that [Expression syntax \[Beta\]](/integrateandcode/expression-syntax.md) allows you to get the flexibility to use code syntax functions in your bot without the need of extensive coding skills.
{% endhint %}


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# Agent Instructions: Querying This Documentation

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Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.chatlayer.ai/navigation/settings/secure-variables-gdpr.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.