UCP Playground — AI Shopping Agent

UCP Playground is the fastest way to test agent-driven shopping flows in your browser. Open any store that publishes a UCP manifest, chat with it from Chrome's side panel, and watch the full tool-call timeline — search, product detail, cart, checkout — exactly as an AI shopping agent would experience it. Built for developers building UCP storefronts, merchants integrating MCP endpoints, and engineers curious about agentic commerce. Anyone who wants to see what AI shopping looks like under the hood. What it does • Detects UCP manifests automatically on any tab you visit (probes /.well-known/ucp — nothing else is read from the page) • Spins up a chat session against the merchant's MCP endpoint via the UCP Playground Headless API • Shows every tool call, argument, response, and timing in the side panel timeline • Renders product cards, cart state, and the merchant's checkout URL as they happen • Hands off to the merchant's native checkout when the agent is done Why not screen scraping? Most "AI shopping" extensions guess at page structure and break the moment a merchant ships a CSS change. UCP Playground talks to merchants through the Universal Commerce Protocol — published manifests, MCP tools, structured responses. Faster, more accurate, and works on any UCP-compliant store without per-site adapters. Pick your model Choose any model exposed by your UCP Playground account. Different models reveal different failure modes — useful when validating that your storefront works across the agent ecosystem, not just one provider. What you can debug • How an agent interprets your product titles and descriptions • Whether your option/variant schema resolves cleanly under natural-language queries • Where checkout flows stall (variant mismatch? auth gate? missing field?) • How tool latency affects agent decisions Privacy • Only the hostname of the current tab is read locally to detect UCP. The full URL is never sent to UCP Playground servers. • The extension does not read page content, cookies, or form fields from the sites you visit. • Chat messages are sent over HTTPS to your account at ucpplayground.com. • Full privacy policy: https://ucpplayground.com/privacy Setup 1. Sign in (free) at ucpplayground.com 2. Generate a personal access token at ucpplayground.com/settings/tokens 3. Paste the token into the extension's options page 4. Visit any UCP-enabled store — the side panel detects it automatically For context: UCP is the emerging standard for how AI agents discover and interact with merchants. A growing list of Shopify and WooCommerce stores publish UCP manifests today — see the full list of validated stores at ucpchecker.com. This extension lets you talk to any of them.