In September a shopper's AI agent hit a pop-up saying it violated Amazon's terms of use. In October Walmart announced a gateway built for exactly that kind of agent. Same agents, opposite answers.

If you build shopping agents, or the e-commerce systems they talk to, this split matters more than either headline. The two retailers are protecting different things, and that decides what your agent is allowed to be. I read both moves closely below, then list what I would design for.

Amazon's answer: the terms of use are the gate

Amazon began blocking Meta's Muse agent from Amazon.com on the night of Sunday 20 September 2026, according to an Amazon spokesperson. Amazon said it had asked Meta to remove Amazon from the Muse experience. Shoppers who try to use Muse on Amazon now see a pop-up saying that doing so violates Amazon's terms of use.

Notice the lever. It is not a new technical wall. It is contract.…