Catalog API image search (like: [{ image }]) returns "Service error" — also fails in Dev Dashboard playground

Text search via search_catalog works great, but image-based search (similar-by-image) consistently fails with a generic service error.

Endpoint: POST https://catalog.shopify.com/api/ucp/mcptools/callsearch_catalog
Agent profile: https://shopify.dev/ucp/agent-profiles/2026-04-08/valid-with-capabilities.json

Request (image branch of like):

"catalog": {
  "like": [{ "image": { "content_type": "image/jpeg", "data": "<base64 bytes>" } }],
  "filters": { "available": true }
}

Response:

{ "error": { "code": -32000, "message": "Service error. Please try again later." } }

It also reproduces in Shopify’s own Dev Dashboard → Catalogs playground: attach an image, hit Search → “Catalog search failed — Service error. Please try again later.” (screenshot below).

Notes:

  • Text queries and similar-by-reference (like: [{ "id": … }]) both work fine — only image content fails.
  • Reproduced with multiple images (69 KB JPEG and larger), many retries over ~an hour, in both my own MCP client and the first-party playground.

Is image/visual search not yet enabled, or is extra setup required (saved catalog, dedicated API key)? Thanks!