Amazon blocks Meta's Muse agent as Shopify opens Shop Pay to AI shopping

Amazon blocks Meta's Muse agent as Shopify opens Shop Pay to AI shopping

In less than a day, the AI shopping agent Muse got two completely opposite answers from the retail world's biggest platforms: Amazon blocked the agent and cited its terms of use, while Shopify and Meta announced a partnership that lets Muse shop and pay in all Shopify stores via Shop Pay. One week has thus outlined the divide now splitting the industry: between open, partner-based agent flows and closed retail platforms — while an unresolved legal question about who is really "visiting" an online store hangs over the entire conflict.

What happened, and when

The timeline is tight. Muse launched in the US on September 8, 2026, and on September 18 topped the list of free apps in the US App Store, according to market analyst Sensor Tower (note.com). On Sunday evening, September 20, Amazon blocked Meta's Muse agent from its store — GeekWire was first to report the news (GeekWire). On Monday, September 21, Shopify CEO Tobi Lütke announced the partnership with Meta on X. On Tuesday, September 22, the market responded: Shopify's stock rose roughly 7 percent in morning trading to $148.01, according to 24/7 Wall St., while Meta rose 11 percent on Monday to its highest closing price in more than a year, according to GeekWire.

Amazon justified the block this way, as quoted by The Motley Fool: "Continued access by an unauthorized AI agent violates Amazon's Conditions of Use, to which our customers have agreed." Amazon has also confirmed the block with reference to security and user experience, according to CBS News. The company's terms additionally require agents to identify themselves in every request, GeekWire writes.

Lütke's announcement read, as quoted by The Motley Fool: "We are excited to announce we are partnering deeply with Muse to enable agentic checkout with Shop Pay on all Shopify stores, giving people a simple and delightful way to shop and check out with Muse."

The integration is built on Shop Pay, Shopify's one-click payment service that stores the customer's payment and delivery details. Muse can thus browse Shopify-powered stores and complete purchases on the user's behalf. Worth noting: neither company has disclosed financial terms, revenue sharing, or a rollout timeline, according to 24/7 Wall St.

The download numbers: How big is Muse?

Interest in Muse has been measured in several different windows, and the figures should be kept apart. Sensor Tower data shared with CBS News shows more than 2.5 million downloads in the roughly two weeks after launch. Over the same period, OpenAI's ChatGPT got 3.1 million global downloads, while Anthropic's Claude got 200,000, according to Sensor Tower (CBS News).

Another, earlier window shows the same trend: Sensor Tower stated, according to note.com, that Muse was downloaded more than 902,000 times in its first six days — more than its predecessor, the Meta AI app, which got 773,000 downloads in a comparable period. These are different measurement windows and different comparisons, not contradictory figures.

The money: Small cut, no terms

So far there is one indication of Meta's business model, but it predates the Shopify deal. Meta CEO Mark Zuckerberg said on the Sources podcast that Muse would "take a very small cut of whatever the transaction is" — potentially paid by the businesses users shop with, according to GeekWire. It is unclear whether this mechanism applies to the Shopify integration, which neither Meta nor Shopify has commented on financially.

Deutsche Bank analysts describe the deal, according to 24/7 Wall St., as a further sign that prominent AI platforms are choosing to work within Shopify's commerce infrastructure (24/7 Wall St.).

Meta has not publicly responded to the Amazon conflict, according to GeekWire.

The legal backdrop: The Perplexity precedent

Amazon's response this time is contractual — a violation of its terms — and it must be read against a pending lawsuit. In its dispute with Perplexity over the Comet browser's agent, Amazon won a preliminary injunction in March 2026. On August 4, the Ninth Circuit Court of Appeals overturned the injunction, finding it unlikely that Amazon would prevail on its anti-hacking claim: it is the user — not the AI company — who accesses Amazon's computers, according to GeekWire. On September 10, the court denied Amazon's request for a rehearing. On Monday, Amazon added a new, contract-based claim to the case.

The precedent frames the Amazon–Meta conflict, but does not decide it. The Ninth Circuit's reasoning may constrain Amazon's contract theory — if it is the user who is shopping, it is unclear how far the terms can go in forbidding the agent the user has authorized. The question of whether platforms can deny user-authorized agents access at all remains unresolved.

Worth noting: Amazon's own agent, Buy for Me, identifies itself, and Amazon allows brands to opt out of it, according to GeekWire. That shows the company does not reject agentic commerce as a matter of principle — only unauthorized agents, per its own definition.

What we don't know

Several significant questions remain open. There are no financial terms, revenue split, or rollout timeline for the Shop Pay integration. It is unclear whether Zuckerberg's "very small cut" model applies to the deal. The legal question — whether terms of use can forbid user-authorized agents — is being litigated. Meta has not commented on Amazon's block.

There is also an unresolved detail in the market reaction: GeekWire writes that Meta's stock rose again on Tuesday morning, while 24/7 Wall St. reports a modest decline on Tuesday. Both could be true intraday, but the accounts differ, and we note the discrepancy rather than resolving it.

Beyond this, caution is warranted with details that are unconfirmed — for example, descriptions of Muse's security design that circulate only through secondary sources. What is known is the frame: one agent, two platforms, two very different answers — and a court system that has not yet said who is right.