> For the complete documentation index, see [llms.txt](https://help.sesami.co/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.sesami.co/apps-integrations/shopify/online-store/cart-verification-script.md).

# Cart Verification Script

Appointments in the cart can become unavailable if someone else books the same slot first.

The **Cart Verification Script** checks availability and prevents double bookings by validating that the selected slot is still available.

{% hint style="info" %}
What customers see

A small storefront notification appears (bottom-left) when Sesami validates the booking.
{% endhint %}

## Enable / manage it

{% tabs %}
{% tab title="Online Store 2.0 themes" %}
This setting may be available as a storefront setting / theme integration option depending on your theme setup.
{% endtab %}

{% tab title="Vintage themes" %}
Go to:

**Sesami → Settings → Validate appointments in cart**

Then enable the checkbox.
{% endtab %}
{% endtabs %}

## Styling

You can customize the style (colors, fonts, etc.).\
See: “How to customize the styles of the Cart Verification Script”.


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

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

```
GET https://help.sesami.co/apps-integrations/shopify/online-store/cart-verification-script.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

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.