UCP Catalog Lookup: Direct Product Retrieval for AI Agents

A new proposal from Ilya Grigorik adds a get product operation to UCP's catalog capabilities — enabling AI agents to retrieve specific products directly rather than searching. A seemingly simple addition with significant implications for agentic commerce efficiency.

About the Author

Ilya Grigorik is a Google engineer leading technical work on the Universal Commerce Protocol. Previously known for his work on web performance and HTTP/2 at Google, Grigorik now focuses on enabling AI agents to conduct commerce on behalf of users. He's authored multiple foundational UCP proposals including message signing, risk signals, and the intent field.

What This Change Adds

Issue #195 proposes adding a get product operation to the catalog.lookup capability. Today, when an AI agent knows exactly which product it wants, it still has to use a search-based flow — inefficient for direct product references.

The new operation would allow agents to request a specific product directly:

{
  "operation": "catalog.lookup",
  "action": "get_product",
  "product_id": "SKU-12345-XL-BLUE",
  "merchant_id": "merchant.example.com"
}

Why This Matters

On the surface, this is a minor API addition. In practice, it unlocks several important patterns:

Direct linking: AI agents can reference products by ID from external sources (shopping lists, saved items, comparison results) and retrieve current availability and pricing directly
Reduced latency: Skip the search-rank-filter flow when the product is already known
Cart reconstruction: When resuming an abandoned session, agents can re-fetch product details without re-searching
Cross-merchant comparison: After identifying products across merchants, get precise details for final comparison

The pattern: Search to discover, lookup to retrieve. This mirrors how humans shop — browse first, bookmark for later. AI agents need the same separation of concerns.

Technical Implications

For merchants implementing UCP, this introduces a new code path:

ID resolution: Merchants must handle product IDs from various sources — their own catalog, GTINs, MPNs, or UPC codes
Access control: Direct lookup may need different authorization than search (bulk lookups could enable catalog scraping)
Availability freshness: Unlike search results (which can be slightly stale), direct lookups may need real-time inventory

What's Next

This proposal is currently open for discussion. The key questions being debated:

Should multiple product IDs be supported in a single request (batch lookup)?
How should variant handling work — can you look up a parent product and get available variants?
What happens when a product ID is no longer valid (discontinued, out of stock, renamed)?

Expect this to merge within the next few weeks as the spec details are finalized. For UCP implementers, this is a good time to review your product ID strategy.

Source: Universal-Commerce-Protocol/ucp#195