Amazon shut Muse out and handed Claude the store keys

Muse hit the wall on a Sunday night

On the night of 20 September 2026, Amazon began blocking Muse, Meta's two-week-old shopping agent ². Try to buy through it and a notice says an "unauthorized AI agent" violates the site's terms↗ ¹. Amazon says Meta never warned it Muse would browse the store, that the agent does not identify itself, and that it appears to capture customer credentials; Meta says passwords and payment methods sit in storage the model cannot read ¹. Muse had already passed ChatGPT as the top free iPhone app in the US, ten days after its 8 September launch ².

The toll an agent's cart would skip

The wall sits where Amazon collects its toll. Advertising brought in $19.8 billion in the second quarter, up 26 percent↗ ³⁴, after more than $68 billion last year ¹. On the 30 July earnings call, chief executive Andy Jassy said shoppers who click a sponsored prompt convert to a sale 48 percent more often and spend 21 percent more on average than those who do not ⁵⁶.

A cart filled by Muse likely never shows one. Amazon has not said the block protects advertising; the rest of its week points that way.

The doors Amazon opened instead

On 23 September, at its Accelerate seller conference, Amazon released a plugin that lets sellers run inventory, prices and listings inside Anthropic's Claude↗; Amazon is a major investor in Anthropic ³. A day later it opened Seller Central to orders from Walmart, eBay, Shopify and TikTok ⁷, put Prime delivery on merchants' own websites at no added cost, and cut fulfillment fees 15 to 25 percent for six months↗ ⁸. Independent sellers are more than 60 percent of units sold ³. The line that emerges: outside agents may run an Amazon store. They may not fill an Amazon cart.

Amazon's case for its own door

The stated line is authorization, not AI. Agents that buy for customers "should operate openly and respect service provider decisions about whether or not to participate," a spokesperson said, the way delivery apps take orders from restaurants that agree to them ¹. Amazon's own Buy for Me agent shops other retailers, identifies itself, and lets them opt out ¹; agents from Google and OpenAI are being shown the same wall as Muse↗ ⁹. Both sides can be right about credentials, and the wall still lands between shoppers and the sponsored prompts.

The first reading lands in late October

Shopify took the other door and got paid: "partnering deeply with Muse to enable agentic checkout with Shop Pay on all Shopify stores," chief executive Tobi Lütke said, with agent orders carrying "the exact economics as an online store transaction," in president Harley Finkelstein's words ². The stock rose about 15 percent in two days ². Amazon is defending the machine that funds a buildout now outrunning its cash: second-quarter capital spending of $53.1 billion against $45.4 billion of operating cash flow ¹⁰.

Prime Big Deal Days run 6 and 7 October↗ ¹¹. The late-October earnings report is the first read on whether advertising still compounds near 26 percent ⁶, and the FTC's case over the $46.8 billion in seller fees Amazon collected last quarter, more than AWS, goes to trial in March 2027 ³.