UCP Playground at 1,000+ Agent Sessions: What 16 Models and 97 Real Stores Reveal About AI Shopping

Two and a half months ago we published Why We Built UCP Playground , which closed on 114 agent sessions and an honest acknowledgement that the dataset was thin — most models had single-digit sample sizes, store coverage was uneven, and the headline rates moved meaningfully with every new run. A month later we crossed a different threshold: the first fully autonomous AI agent purchase through UCP — a Gemini agent searching, adding to cart, linking identity, paying, and completing checkout at hous