Storefront API / MCPAction Required

Storefront Catalog MCP
now complies with UCP: tool names and endpoints overhauled

The MCP tools for product catalogs are search_catalog / lookup_catalog / get_product — reorganized into these three. The call targets now point to /api/ucp/mcp . The old tools remain available until June 15, 2026, then will be removed.

On this page
  1. What's actually changing (a 30-second overview)
  2. The three new catalog tools
  3. Endpoint changes
  4. Migration schedule (deadline: 2026/6/15)
  5. Three steps to take
  6. What is UCP? (as covered in this article)
  7. Five points for developers to note
  8. Three practical use cases
  9. A one-line summary you can use in pitches

1What's actually changing

The Storefront Catalog MCP tools have been overhauled to comply with UCP.
The previous search and lookup tools are now deprecated , and are replaced by three new tool names, new endpoints, and new request/response formats.

Before: the old search / lookup tools

Used the previous search and lookup tools, with request/response formats on the old spec. Maintained until June 15, 2026, then removed.

Going forward: three UCP-compliant tools

search_catalog / lookup_catalog / get_product — reorganized. The call target moves to /api/ucp/mcp. The formats are also updated to match UCP.

This article is tagged Action Required. If you build with Storefront MCP tools, you'll need to update tool names, endpoints, and schemas. All documentation now points to the new version.

2The three new catalog tools

search_catalog

Search a store's product catalog.Filtering, pagination, and buyer contextare supported.

lookup_catalog

Look up products and variants by identifierin batch. Supports inputs correlation.

get_product

A product'sfull detailsretrieved. Includes interactive variant selection, availability signals, and more.

ToolRoleFeatures stated in the article
search_catalog Catalog search Filtering / pagination / buyer context
lookup_catalog Bulk retrieval by identifier Batch lookup of products and variants / inputs correlation
get_product Retrieve details for a single product Variant selection / availability signals / more

3Endpoint changes

Old: search / lookup tools Old request / response format Maintained until 2026/6/15 → retired Migration https://{storedomain}/api/ucp/mcp • search_catalog • lookup_catalog • get_product UCP compliant Product catalog
New tool calls are made https://{storedomain}/api/ucp/mcp .{storedomain} should be replaced with your own store domain. As for the specific path of the old endpoint,not stated in the article.

4Migration schedule

2026/4/22 New tools released Old tools deprecated ← Period during which old tools remain supported → 2026/6/15 Last day old tools are supported Retired after this New tools only after this
The old version is until June 15, 2026 supported. However, since all documentation will now reference the latest version, it's safest to build new implementations with the new tools from the start.

53 steps to take

What you need to do if you're building with Storefront MCP tools (from the article's "What you should do").

1

Update the tool names

search_catalog / lookup_catalog / get_product with one of the following.

2
/ucp/mcp

Update the endpoint

Change the call target to https://{storedomain}/api/ucp/mcp .

3

Update the schema

Review the new request/response schemas for all tool calls and update your app to match.

For details, see the Storefront Catalog MCP documentation(the post links to it). Note that the request/response shapes change to match UCP, so this is more than just renaming the tools.

6What is UCP? (the scope of what the post covers)

This post (the Developer Changelog) states that the Storefront Catalog catalog tools "implement UCP" , and that the request/response shapes are updated "to match UCP" , as the post describes.

The full name and definition of the acronym UCP itself are not given in this post. Avoid guessing; confirm the exact definition and specification in the official documentation. On this page we treat it as "the new specification that the catalog tools conform to."

Similarly,buyer context / inputs correlation / availability signals such terms are mentioned by name in the post, but their specific field specifications are not described. Confirm them in the schema documentation before implementing.

7Five points engineers should keep in mind

1. The deadline is June 15, 2026

The old tools are maintained until this date and then deprecated. This is an Action Required breaking change, so live apps need a migration plan in place by the deadline.

2. Tool renaming

From the old search/lookup tools to search_catalog / lookup_catalog / get_product . Rewrite every tool reference on the MCP client side.

/api/ucp/mcp

3. Endpoint consolidation

Calls are consolidated to /api/ucp/mcp . Externalizing it as a base URL or environment variable makes migration and rollback easier.

4. More than a rename

The request/response shape itselfchanges to become UCP-compliant. Estimate on the assumption that parsers, type definitions, and validation will all need updating.

UCP

5. The new concepts require reading the docs (the post only gives names)

Feature names like buyer context, inputs correlation, and availability signals are tied to the new tools, butthe definition of UCP and the detailed specification of each field are not described in this post. Be sure to check the Storefront Catalog MCP schema documentation before implementing.

8Three use cases you can apply to your business

USE CASE 1

Migrate product search in AI shopping assistants / chat commerce to UCP

Challenge
Your AI agent / chatbot depends on the old Storefront MCP search and lookup. Once they are deprecated on 2026/6/15, product recommendations stop.
Solution
search_catalog Rename toget_product , change the endpoint to /api/ucp/mcp , and remap the response to match the new schema.
Impact
Keeps running even after the deprecation. Personalized search using buyer context, plus inventory signals that avoid recommending out-of-stock products to improve the experience.
Technical notes
The response shape changes, so updating parsers and type definitions is required. Switch between old and new via an environment variable to prepare for phased migration and rollback.
USE CASE 2

Rebuild product matching for external system integrations with lookup_catalog batch retrieval

Challenge
Matching against PIM, inventory management, ad feeds, and the like by SKU and product ID relies on the old lookup tool, and the volume is high.
Approach
lookup_catalog 's batch identifier lookup, and useinputs correlation to correlate the entered identifiers with the returned results.
Impact
Batch queries cut the number of round trips. Correlation makes it more robust to pinpoint IDs that weren't found and to detect mapping mismatches.
Technical notes
Check the input/output format of inputs correlation in the schema documentation. Also understand the batch limits and pagination specs before migrating.
Suppress with inventory signals
USE CASE 3

Enhance the variant selection UX with get_product 's inventory signals

Challenge
When customers choose a size and color, they can't see stock availability, which leads to cancellations and inquiries when items turn out to be out of stock after purchase.
Approach
get_product 's interactive variant selection and availability signals to suppress and gray out out-of-stock variants.
Impact
Reduces showing variants that can't be selected, driving CVR improvements and lowering cancellations and customer support load.
Technical notes
availability signals are included in get_product 's new response. Switch the display logic to be driven by inventory signals.

9A one-line summary for your pitch

"The Storefront Catalog MCP tools have been revamped to be UCP-compliant.
search_catalog / lookup_catalog / get_product 's three tools, plus the/api/ucp/mcp endpoint— migration is required.
The old tools will be deprecated on June 15, 2026— update three things: tool names, endpoints, and schema."