The RealReal blocks AI agents after Muse exploited its 20-minute cart hold

A rule written for human shoppers broke the moment an AI agent ran it in a loop. The RealReal is a secondhand luxury fashion retailer. It said it has changed its bot defence after Meta's Muse locked other buyers out of designer items for hours. The retailer told The Verge the change makes it harder for all agents to log in or check out.

The Verge reported the exploit this week. An item on the retailer's site goes on hold for 20 minutes once added to a cart. The hold is there for shoppers who want time to decide. The Verge used Meta's Muse to re-add listings every time the 20-minute hold ended. Other shoppers could not buy the items for hours or longer, as long as the loop ran.

What the retailer changed

The RealReal's chief technology officer, Luke Friang, emailed The Verge after the first story went out. He said the company had addressed the Muse use case. Agents now have a "much more difficult" time logging in, adding items to the cart and checking out, Friang said. Agents can still surface listings and send Muse users to product pages. Friang said the company will keep strengthening protections "as AI-powered online shopping evolves". Meta did not respond in time for publication.

Why the exploit mattered

Meta said on its Q3 earnings call that shopping is the most common use for Muse so far. The company reports that purchases through the agent run over $200 on average. Meta said 10 million people in the United States had downloaded the app in 40 days. The reserve system worked when a human was on each end of it. A human sitting at a laptop will stop re-adding dresses after a few tries. An agent does not stop.

What a product team should take from this

Every rate limit, cart hold and reserve window on a public site was written for a human. The number was chosen for how long a human takes to decide, pay, or come back. Each of those numbers was fine until agent traffic reached ten million people. A team running a listings site, a booking flow or a free tier should audit each of those numbers. The question: what happens if an agent runs this loop a thousand times a day, from many accounts.

The Verge frames the choice around how the open web works. A business is one step removed from the customer if humans reach a site only through a chatbot. Amazon has blocked agents. Walmart has set up a gateway for them. The RealReal has moved to block them for now. None of these is a settled answer, and The RealReal's own statement says it will keep adjusting.

What the piece does not settle

The Verge did not report how many items had been held this way. It did not say how many purchases were blocked, or what the dollar impact was. The retailer did not share those numbers. The outlet also did not test whether the new bot defence stops the same loop. The next test, when somebody runs it, will be the real measure of the change.

Source

• Primary source: The Verge, "The RealReal won't let AI agents hog designer clothing", by Mia Sato.