Shopify's AI commerce category filter found non-functional across 186 of 190 stores tested

Researchers tested 190 Shopify storefronts to evaluate the category filtering feature of the platform's agent-commerce endpoint, introduced in 2026, which allows AI agents to query product catalogues. The search_catalog tool advertises support for filtering results by product category, meaning an AI agent should theoretically be able to request a specific product type and receive only matching results. Of the 190 stores that responded, 186 ignored the category filter entirely and returned a full, unfiltered product set, while none filtered correctly. Notably, the price filter within the same API request worked correctly on 150 of the 190 stores, confirming the endpoint itself was functional and isolating the category filter as the specific failure point. The researchers clarified this was not a criticism of Shopify, noting the UCP feature only shipped in 2026 and that category filtering may still be maturing.