> ## Documentation Index
> Fetch the complete documentation index at: https://docs.colossal.sh/llms.txt
> Use this file to discover all available pages before exploring further.
# Storefront
> Cart and checkout operations an automation can run as App Action steps.
Built-in cart and checkout operations an [automation](/automations/overview) can run as App Action steps.
## Cart
Add a product to the cart.
**Input**
Cart UUID
Product UUID to add
Quantity to add *min: 1. Default: `1`.*
**Output**
Retrieve cart details by UUID.
**Input**
Cart UUID
**Output**
Remove an item from the cart.
**Input**
Cart UUID
Line item ID to remove *min: > 0.*
**Output**
Update the quantity of a cart item.
**Input**
Cart UUID
Line item ID to update *min: > 0.*
New quantity *min: 1.*
**Output**
## Checkout
Retrieve checkout session for a given order.
**Input**
Order ID *min: > 0.*
**Output**
Retrieve checkout session details by UUID.
**Input**
Checkout session UUID
**Output**