Cart
Carts are smart buyer assistants that contain the merchandise that a buyer intends to purchase and information about the buyer.
This guide introduces carts within the context of the buying journey, ways that you can extend a cart's functionality, and some considerations before you get started with building carts.
How it works
Anchor link to section titled "How it works"The following components form a part of every buying journey:
- A storefront is where merchants tell their brand story, and where customers browse available products.
- A cart is where customers add products that they're interested in buying, and remove products that they no longer want to buy. A customer might visit their cart multiple times to renegotiate with themselves before they make a final purchase.
- A checkout is where a customer makes their final decision to purchase products, and completes a transaction.
The carts that most buyers encounter are simple baskets that are only used to collect products. They lack functionality and context, and typically lead to buyer frustration at checkout.
Shopify-powered carts provide the following benefits:
- Display accurate and personalized discounts, tax, and shipping estimates.
- Provide price transparency in real time, and at each new step of the purchase journey.
- Run brand-provided custom business logic.
- Shortcut buyers through checkout by providing known buyer preferences, such as payment methods or shipping details.
- Offer fast and predictable performance no matter the size of the store or the sale.
Extensibility options
Anchor link to section titled "Extensibility options"Many merchants have unique business requirements. You can extend the functionality of a cart, while ensuring it's performant, reliable, and scalable in checkout, in the following ways:
| Feature | Description | Example use cases |
|---|---|---|
| Shopify Functions | Extend and customize Shopify's default logic and provide consistency throughout the buyer journey. | Create a custom validation function that can be executed by Shopify on every cart update to do the following:
|
| Metafields | Create metafields to extend the cart schema with custom values and logic at checkout. | Attach custom structured metadata on a cart, and read it from a checkout extension to deliver a customized end-to-end buyer experience. |
| Preferences | Set customer preferences to provide a personalized cart and checkout experience. | Provide a list of preferred delivery addresses to accelerate the checkout flow, and best optimize conversion. |
International pricing
Anchor link to section titled "International pricing"Carts offer contextual experiences based on location, language, and pricing. You can query international prices for products and orders, and explicitly set the context of a cart.
Users can configure the prices of products on a per country basis in their Shopify admin. For example, a storefront might have default prices for products set in USD, and price adjustments configured for Canada (CAD), Australia (AUD), and France (EUR).
The following diagram shows the different prices of the same product based on customer location:
Speed and scale
Anchor link to section titled "Speed and scale"Shopify's cart functionality is built on the same infrastructure as our storefronts. Carts are deployed globally and deliver a low-latency experience to buyers around the world.
Carts don't have any global API rate limits. This means that merchants can confidently launch their biggest flash sale, or absorb an unexpected wave of buyers.
Developer tools and resources
Anchor link to section titled "Developer tools and resources"Explore the following developer tools and resources to learn more about working with carts.
Product Roadmap
Anchor link to section titled "Product Roadmap"| Feature | Release Target |
|---|---|
| Cart API Migration Guide | 2024-04 |
| Append Gift Card to Cart | 2024-07 |
| Query and Set Carrier Calculated Shipping Rates | 2024-07 |
Support Asynchronous Calls with @defer Directive |
2024-07 |
Cart.buyerIdentity Authentication Carried Through to Checkout |
2024-07 |
| Support for Native Wallets (Apple Pay, Google Pay) in Mobile Apps on Cart | 2024-07 |
Limitations and considerations
Anchor link to section titled "Limitations and considerations"- The cart is subject to the same throttling restrictions as the Storefront API.
- The cart supports a maximum of 500 line items.
- A shop or customer can create an unlimited number of carts.
- Unused and abandoned carts automatically expire within 10 days of creation.
- Shopify automatically deletes the cart when the customer completes their checkout.
- Shopify Plus bot protection is available for cart.
- Learn how to create and update a cart in Shopify with the Storefront API.
- Learn how to migrate to the Cart API