Shopify has put a hard date on a change that product discovery tools have known about since spring, and the timeline left for anyone who delayed is now measured in days rather than months. The Global Catalog REST API was deprecated in April 2026, and Shopify confirmed in a developer changelog entry dated October 9 that the API stops serving traffic on November 2, 2026, after which every request to the old discover.shopifyapps.com/global address will fail, including requests made against saved catalogs that teams may have assumed were settled and safe.
The affected surface is specific, and Shopify listed the endpoints plainly so that no developer can claim the scope was unclear. Search through the old global endpoint, single product lookup, lookup by variant, and bulk lookup through a POST request all go dark on the same day, and each one maps to a tool inside Global Catalog MCP, which sits at a new address and implements the Universal Commerce Protocol. Search becomes the search_catalog tool, product and variant lookups become get_product, and bulk lookup becomes lookup_catalog, which accepts batches of up to 50 items in a single request.
The migration involves more than swapping an address, because the request shape changes along with the transport. Every MCP request must include the agent profile URL inside the request metadata, saved catalogs are now referenced by passing a catalog ID in the request rather than calling a dedicated saved catalog endpoint, and responses follow the UCP catalog schemas, which means response handling code needs review as well as request code. Authentication stays familiar, since teams keep generating bearer credentials from Dev Dashboard client credentials, and that continuity should remove one common excuse for leaving the work until the final weekend.
For merchants, the direct risk sits with the third party tools layered on top of a store rather than with the storefront itself, and that distinction matters when triaging the next two weeks:
- Price comparison, product search, and affiliate tools that still call the REST endpoints will stop returning Shopify products altogether once traffic stops, and a silent failure of that kind can look like a demand drop before anyone traces it to a dead integration.
- Saved catalogs are not exempt, so a curated catalog that feeds a shopping agent or a partner site needs testing through the MCP path even when the underlying product data has not changed in months.
- Buyer context, filters, and pagination travel through the new search tool, so a migration that only checks whether results return at all can still ship a weaker discovery experience than the one shoppers had before.
A sensible migration sequence for any team still on the old API looks like this:
- Inventory every place the old global address appears across production code, scheduled jobs, and partner integrations, because the calls that break are often the quiet background jobs that nobody has opened since launch.
- Map each call to the matching MCP tool and rebuild the request with the agent profile included, then compare returned products, variants, and availability signals against the REST responses while both paths still work.
- Test saved catalog lookups by passing the catalog ID in the request, and confirm that filters and pagination behave the same way for the queries buyers actually run rather than for a single convenient test query.
- Ship the change well before November 2 and monitor error rates through the switch-off week, so a missed endpoint surfaces while time remains to respond calmly.
The commercial context explains why Shopify is pushing discovery toward an agent ready protocol instead of maintaining a conventional catalogue feed. I covered the demand side of this shift when I wrote about AI-referred Shopify sessions converting far better than ordinary organic sessions, and a catalogue that agents can query in a structured way is the supply side of that same story. A store whose products are easy for an agent to find, compare, and verify stands a better chance of being the product an answer recommends, while a store hidden behind a broken integration simply drops out of consideration.
Failon’s POV: I read this deadline as a sorting event for the Shopify app ecosystem rather than a routine deprecation notice. Tools that move early will keep their place inside agent driven discovery while tools that miss the date will hand their merchants a visibility problem that no amount of on page optimisation can repair, because the products will not be in the catalogue the agent searches at all. If a merchant pays for any tool that searches across Shopify stores, I would ask that vendor today which protocol the tool calls, and I would want the answer in writing before November arrives.
Sources: Shopify developer changelog, Global Catalog REST API stops serving traffic on November 2, 2026 (October 9, 2026), and TrustList News coverage of the same change.
