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Agent checkout pitfalls

Where AI shopping agents fail at checkout: stale prices, dark patterns, wrong SKU, subscriptions, and returns you cannot undo from a chat.

Computer-use shopping demos skip the boring failures. Here they are.

Stale price / wrong SKU

The matrix said $89. Checkout is $89 plus a “convenience” SKU that is a different product. Eval: the human loads the cart line, not the chat summary.

Dark patterns

Pre-ticked insurance, “subscribe and save,” leftover gift-card balance applied to the wrong account. Agents click Continue the way tired humans do.

Account soup

Logged into the agent’s browser profile, not yours. Order goes to an old address. Returns become archaeology.

Subscription gravity

The agent “saved 15%” by subscribing you to detergent forever. Put no subscriptions in the spec unless you mean it.

Returns and liability

Who is the merchant of record when an agent used a meta-checkout? If you cannot answer, you are not ready. Pay By Prompt for rails; this page is only the shopping-shaped failures.

Mitigation

  • Spec: “Do not submit payment. Stop at cart screenshot / list.”
  • Cap + confirm if you ever enable submit
  • Trace of URLs
  • You click the live cart once

When not to let an agent buy.