The pilot sample just grew: American Express joins the ten institutions tracked since launch, bringing the total to 11 institutions and 18 documented vendor relationships.
The documented relationship
American Express integrated Resy — its restaurant-reservation subsidiary — as an app inside Claude, Anthropic's AI assistant. Amex cardmembers can ask Claude to check a restaurant's eligibility or get recommendations, directly from within the Claude ecosystem. Confirmed by emarketer.com on April 27, 2026 — see the full row and the cited source.
A distinction that matters
Amex GBT (American Express Global Business Travel) has, separately, integrated Claude for business-travel booking. We don't count this second integration as a distinct relationship: Amex GBT is a different legal entity, majority-independent since 2014, even though American Express remains a minority shareholder. That's exactly the kind of distinction the methodology asks us to document precisely rather than aggregate for convenience.
What we didn't find — and why it stays a note
While searching to expand the sample toward the priority targets identified (U.S. Bancorp, PNC Financial Services, Truist Financial, Capital One), none of these four institutions had a publicly documented foundation-model vendor relationship as of today. Charles Schwab did launch a generative AI feature in May 2026, but its own press release doesn't name the model vendor — impossible to classify by family without that detail.
Rather than force a rough match, these leads stay open on our research target list. The index is only as good as the rigor of its sources.