How Napster Agent connects to your Shopify store

Integration Guide · Updated September 30, 2026 · 5 min read

Overview

Napster Agent integrates with Shopify's Storefront MCP (Model Context Protocol) server and UCP Cart MCP server to give your customers an AI-powered shopping experience. Through these connections, an AI assistant can search your product catalog, manage shopping carts, and guide shoppers to checkout — all within a natural conversation.

No setup required. Napster Agent connects to your store's existing storefront data automatically through Shopify's built-in endpoints. No apps to install, no code to write, and no configuration needed in your Shopify admin.

Update — Shopify's UCP transition. In June 2026 Shopify moved cart tools from the Storefront MCP server to a new UCP-conforming Cart MCP server. The older cart tools were retired on August 31, 2026. Napster Agent uses the new UCP Cart MCP endpoint for all cart operations — the migration was completed ahead of the retirement date and is invisible to store owners; your integration continues to work automatically.

How it works

When a customer asks a question, here's what happens:

1. Customer asks a question — A shopper browsing your store asks about products through the Napster Agent AI assistant — just like talking to a knowledgeable store employee.
2. AI searches your catalog — The assistant queries your store's Storefront MCP server to find matching products, complete with pricing, images, descriptions, and direct links.
3. Cart is managed — The assistant can create a cart, add items, update quantities, remove products, and share a checkout link — all within the conversation.
4. Customer completes checkout — The shopper is directed to your store's native Shopify checkout to finalize their purchase using your configured payment methods and shipping options.

Everything runs through Shopify's secure infrastructure. Your product data, pricing, and inventory are served in real time — no syncing or data duplication.

Product catalog search

The search_catalog tool lets the AI assistant search your entire product catalog on behalf of the customer. It supports natural-language queries, so shoppers can describe what they want the way they'd ask a real person.

Tool rename. This tool was previously called search_shop_catalog. Shopify renamed it to search_catalog in April 2026. Napster Agent uses the current name.

What customers can do

• Search for products by name, category, or description
• Ask for recommendations based on preferences or use cases
• Browse results that include product names, prices, images, and direct links to your store

What's returned to the customer

Example interaction

Customer: "I'm looking for organic coffee beans, preferably fair trade."

Napster Agent AI: "I found 3 options in the store! Here are the top matches:

• Fair Trade Organic Blend — $18.99
• Single Origin Ethiopian — $22.50
• Decaf Organic Roast — $16.99

Would you like to add any of these to your cart?"

Shopping cart management

Napster Agent provides full cart functionality through Shopify's UCP Cart MCP endpoint (https://{your-store}.myshopify.com/api/ucp/mcp). Four tools are exposed there: create_cart, get_cart, update_cart, and cancel_cart.

Creating a cart

create_cart opens a new cart with the customer's first items. This happens automatically the moment a customer decides to add something — you don't need to do anything.

Retrieving the cart

get_cart retrieves the current contents of a customer's cart, including all items, quantities, prices, and a direct checkout URL. The AI assistant can show customers their cart at any point during the conversation.

Important: the cart lives on Napster Agent throughout the conversation. It is not synced back to Shopify's own cart storage until the customer clicks through to checkout.

Updating the cart

update_cart handles all cart modifications:

• Add items — Products found via catalog search are added using their variant ID.
• Update quantities — Customers can change the quantity of any item in the cart.
• Remove items — Setting a quantity to 0 removes the item entirely.

(Under the hood, update_cart uses PUT semantics — each call replaces the cart's full state. This is handled automatically by Napster Agent.)

Cancelling a cart

cancel_cart discards an in-progress cart. This is called if the customer explicitly decides not to continue.

Checkout

When the customer is ready to buy, the assistant provides a direct link to your store's Shopify checkout. Payment is processed through your standard checkout flow, including any customizations, payment methods, and shipping options you've configured.

Example interaction

Customer: "Add 2 bags of the Fair Trade Organic Blend to my cart."

Napster Agent AI: "Done! I've added 2× Fair Trade Organic Blend ($18.99 each) to your cart. Cart total: $37.98. Ready to checkout, or keep browsing?"

Customer: "Actually, make it 3 bags."

Napster Agent AI: "Updated! Your cart now has 3× Fair Trade Organic Blend. New total: $56.97. Here's your checkout link when you're ready."

Your store's endpoints

Every Shopify store has two dedicated endpoints that Napster Agent connects to automatically. No configuration is required.

Endpoint format

Catalog search — Storefront MCP:

https://{your-store}.myshopify.com/api/mcp

Cart operations — UCP Cart MCP:

https://{your-store}.myshopify.com/api/ucp/mcp

Replace {your-store} with your Shopify domain. For example, if your store is cool-beans-coffee.myshopify.com, your endpoints are:

• https://cool-beans-coffee.myshopify.com/api/mcp (catalog)
• https://cool-beans-coffee.myshopify.com/api/ucp/mcp (cart)

Key details

• No authentication required — Both endpoints are publicly accessible, similar to your online storefront. Only exposes data already visible on your online store.
• Real-time data — Changes you make in your Shopify admin are immediately reflected.
• Secure by design — Read-only catalog access plus standard cart operations. No admin access, no customer account data, no order history.

Feature reference

The table below summarises all Shopify tools and their status in the Napster Agent integration.

Policy & FAQ search is not active. The search_shop_policies_and_faqs tool is available on Shopify's Storefront MCP server but is not currently used by Napster Agent. This capability may be added in a future update.

Frequently asked questions

Do I need to install anything? No. The endpoints Napster Agent uses are built into every Shopify store. Napster Agent connects to them automatically — no apps, no code, no admin configuration needed.

Will this affect my existing online store? Not at all. The endpoints operate alongside your storefront. They serve the same publicly visible product data. It doesn't modify your store settings, themes, or customer data.

What product data is shared? Only data already publicly visible on your storefront: product names, descriptions, prices, images, variant information, and URLs. No private or admin-only data is exposed.

Can the AI assistant process payments? No. The assistant helps customers build their cart and then directs them to your standard Shopify checkout. All payment processing happens through your existing checkout flow.

How quickly are product changes reflected? Changes are reflected in real time. When you update a product's price, title, description, or availability in your Shopify admin, those changes are immediately available through the endpoints.

Is this secure? Yes. The endpoints provide read-only catalog access and standard cart operations. They cannot access your admin panel, customer accounts, order history, or any private data.

What changed with Shopify's UCP transition? In June 2026, Shopify moved cart tools from the Storefront MCP server to a new UCP-conforming Cart MCP server, and the older cart tools were retired on August 31, 2026. Napster Agent migrated to the new UCP endpoint ahead of the retirement date, so the transition was invisible to you as a store owner — the integration has kept working without interruption.