This is the full loop, no hand-waving: an agent that discovers a product, decides, and completes a real order — built from the three protocols this site is about.
The architecture
Three pieces. An MCP server exposes commerce tools to the model (search, compare, get shipping options). A UCP surface makes the storefront discoverable and machine-readable. An ACP backend handles the checkout session and delegated payment.
agent (MCP client) → search_products MCP tool → read storefront UCP surface → create session ACP checkout → complete + pay ACP delegated token
What surprised me
The hard part was not the protocols — it was trust boundaries. The agent never holds raw card data; the delegated token is scoped to one session, one amount. Idempotency keys on completion meant retries never double-charged, even when I killed the connection mid-payment on purpose.
Total wire time for a full purchase: under four seconds. The agentic web is not a demo anymore.
If you'd rather not build the plumbing yourself, that's what the products are: the protocol plumbing, delegated payments, webhooks, and test suites — ready to point at your stack.
Golam Mostafa builds ACP, UCP, and MCP infrastructure at saify.dev. Get every deep-dive and every product with All-Access.