Amazon has shut Meta’s new Muse personal AI agent out of Amazon.com, and within roughly a day Shopify moved in the opposite direction, announcing that Muse will be able to complete purchases through Shop Pay on every Shopify store. The two decisions, taken by the largest online retailer in the United States and the platform behind millions of independent merchants, mark the clearest split yet over who gets to control the checkout when software, not a person, is doing the shopping.
The block went live on Sunday night, September 20, according to GeekWire and TechCrunch. Shoppers who asked Muse to buy something on Amazon began receiving an error message that read: “Continued access by an unauthorized AI agent violates Amazon’s Conditions of Use, to which our customers have agreed.” Shopify CEO Tobi Lütke then posted on X on Monday that the company is “partnering deeply with Muse to enable agentic checkout with Shop Pay on all Shopify stores.” The Wall Street Journal and Bloomberg both reported the developments on Monday evening.
In short
- Amazon blocked Meta’s Muse from transacting on Amazon.com on the night of September 20, citing undisclosed access, credential capture and the agent’s failure to identify itself.
- Shopify went the other way: Lütke announced Shop Pay agentic checkout for Muse across all Shopify stores, with merchants discoverable by default through the Universal Commerce Protocol.
- Muse is 13 days old and already the No. 1 free iOS app in the US, with about 2.5 million downloads per Sensor Tower data cited by CNBC; Meta shares rose more than 11% on Monday.
- The legal ground has shifted: the Ninth Circuit ruled in August that Perplexity’s Comet agent did not violate anti-hacking law by shopping on Amazon, and denied a rehearing on September 10, leaving Amazon its terms of service and trademark claims.
- For sellers the divide is practical: Amazon third-party sellers stay behind Amazon’s wall, while Shopify merchants are now reachable by one of the fastest-growing consumer apps in the country.
What exactly did Amazon do to Meta’s Muse?
Amazon’s action was a technical block paired with a public explanation. Muse sessions that attempted to browse, add to cart or pay on Amazon.com began failing on Sunday night with the Conditions of Use message. GeekWire reports that Amazon first tried, without success, to get Meta to voluntarily exclude Amazon.com from the Muse experience before it cut off access on its own.
An Amazon spokesperson told The Register and GeekWire: “We think it’s fairly straightforward that third-party applications that offer to make purchases on behalf of customers from other businesses should operate openly and respect service provider decisions about whether or not to participate.” The company said it remains in direct conversation with Meta and declined to say whether it would take legal action.
Amazon laid out three specific objections, according to GeekWire’s account of the company’s position. First, Meta did not tell Amazon that Muse would access the store. Second, the agent does not identify itself as automated when it browses. Third, Muse appears to capture and store customer credentials, and can move through account pages and order history as what Amazon called an undisclosed third party inside a customer’s account.
How Meta answered
Meta disputed the security framing. The company said Muse “has no visibility into people’s passwords or payment methods,” and that credentials a user shares are placed in “secure storage, so Muse can use them without seeing them.” Meta declined further comment to several outlets, including American Banker.
The disagreement is narrower than it sounds. Amazon is not accusing Meta of stealing passwords; it is objecting to an agent that logs into Amazon accounts using a customer’s saved credentials without Amazon’s knowledge or consent. Meta’s reply addresses whether the model itself can read those credentials, not whether Amazon agreed to the arrangement. That gap, consent rather than exposure, is where the dispute actually lives.
What is Muse and why did it grow so fast?
Meta launched Muse on September 8 as a personal AI agent rather than a chatbot. It opens a browser inside a secure virtual machine, fills in forms, sends email, manages calendars, books tables and pays for things, and according to Meta it keeps working after the user closes the app. Where a service exposes a public API, Muse uses stored credentials to call it; where there is no API, it drives the website through the browser. That second mode is the one Amazon objected to.
Meta says the agent asks for user approval before sensitive actions such as sending money, and that the browser session runs in an isolated environment rather than on the user’s device. In practice that means a shopper can hand Muse a saved Amazon login once and then issue instructions like “reorder the coffee I bought last month,” with the agent navigating order history, the product page and the buy box on its own. From Amazon’s perspective, the request looks like a customer session with a browser it does not recognise, executing at machine speed, on behalf of a company that never asked permission.
Muse is free up to a usage cap, with two paid tiers Meta lists as Power at $20 a month and Maximum at $100 a month. It is available on iOS, Android, the muse.ai website and inside WhatsApp. Sensor Tower data reported by CNBC put downloads at roughly 730,000 in the first five days and about 2.5 million within 13 days of launch, split between about 1.5 million on iOS and 1.1 million on Google Play, excluding web and WhatsApp usage. Muse became the No. 1 free app in Apple’s US App Store within its first week, ahead of ChatGPT.
Investors treated the app’s early traction as evidence that Meta’s AI spending is producing a consumer product. Meta shares rose about 6% on the day Muse was unveiled and gained more than 11% on Monday, September 21, per CNBC. Market reports put the cumulative rally since launch at roughly 21%, leaving the stock within about 7% of its August 2025 record. Options data firm SpotGamma reported Monday options volume at about 4.5 times the 30-day average, with founder Brent Kochuba describing the inflows as “huge” and driven by “AI hype around their Muse.”
How Muse compares with rival AI apps
| App | Downloads in comparable 13-day post-launch window | Platform note |
|---|---|---|
| ChatGPT (OpenAI) | About 3.1 million | Launched as a chat interface; shopping added later |
| Muse (Meta) | About 2.5 million | Launched as an agent; iOS, Android, web, WhatsApp |
| Claude (Anthropic) | About 400,000 | Assistant-first, agentic features layered on |
| Grok (xAI) | About 200,000 | Bundled with X, standalone app later |
Source: Sensor Tower estimates as reported by CNBC on September 21, 2026. Figures are app-store downloads only and exclude web use.
Two things stand out in that table. Muse is the only one of the four that launched with a working checkout as a core feature, which is why a retailer’s reaction arrived within two weeks rather than two years. And its download curve is close to ChatGPT’s, which means the population of users who could point an agent at Amazon.com is already in the millions.
How did Shopify respond, and what does Shop Pay checkout for Muse involve?
Lütke’s post on Monday was short: “We are excited to announce we are partnering deeply with Muse to enable agentic checkout with Shop Pay on all Shopify stores, offering people an easy and delightful way to shop and check out with Muse.” The Journal reported the arrangement the same evening under the headline “Shopify to Use Meta’s Muse for Agentic Checkout.”
The mechanics matter for merchants. According to American Banker, Muse searches Shopify’s catalog to find products matching a shopper’s prompt and then checks out through the Universal Commerce Protocol, the standard Shopify co-developed with Google. Shopify merchants are discoverable in Muse by default, with product data flowing through Shopify Catalog. Rather than the earlier instant-checkout mechanic, the purchase completes through an in-app browser using vetted credentials the human buyer already has on file with Shop Pay, and those credentials are scoped to a single purchase to protect card data.
Meta now sits alongside ChatGPT, Google AI Mode and Gemini, and Microsoft Copilot as an AI channel inside Shopify’s Agentic Storefronts sales channel. Merchants who have already worked through preparing a store for AI shopping agents will recognise the pattern: Shopify handles discovery, identity and payment, and the agent handles the conversation.
Why Shopify’s business model makes this easy
Shopify’s incentives run in the opposite direction to Amazon’s. Shopify earns most of its revenue from payment processing and subscriptions rather than advertising, so it does not lose money when a shopper never sees a product page. In its second quarter of 2026, per American Banker, Shopify reported gross merchandise volume of $116 billion, up 32% year over year, with Shopify Payments handling 68% of that volume. Shop Pay users repeat within 12 months at a 75% rate and spend roughly 16% more per order than non-Shop Pay buyers.
Every one of those numbers improves when checkout is easier and identity is already verified, which is what an agent handing off to Shop Pay delivers. Rohit Mishra, Shopify’s vice president of product, told American Banker: “Agentic commerce really excites us. The agents don’t have the same challenges as humans.” Aaron Press, research director at IDC, added the caveat that “conversion is the key, and if the handoff from discovery to shopping cart to payment isn’t smooth, abandonment rates will be high.”
Why does Amazon fight outside agents while building its own?
Amazon’s objection is consistent with a year of decisions. Its advertising business generated more than $68 billion in revenue last year, according to The Register and GeekWire, and that revenue depends on shoppers seeing sponsored listings, recommendation modules and Amazon’s own ranking. An external agent that searches, compares and buys on a user’s behalf never renders those surfaces, which means the ad never loads.
There is also an operational argument that TechCrunch highlighted: if Muse places a wrong order, Amazon is the party that handles the return, the refund and the seller complaint. Amazon has framed its stance as a matter of open dealing. Its own outbound agent, Buy for Me, identifies itself to the brand sites it shops and lets those brands opt in or out. Amazon is asking Meta to follow the same rule it says it follows elsewhere.
Amazon’s approach is one of three that large retailers have settled on. Shopify opens its merchants to outside agents through a protocol and a payment wall. Walmart has chosen to build its own agent, Sparky, and to keep third-party agents at arm’s length rather than blocking them outright, a contrast TipRanks drew when The Information first reported Amazon’s robots.txt changes in 2025. Amazon blocks. The difference is not about technology; each company has the engineering capacity to do any of the three. It is about which revenue line each company is protecting.
Amazon’s in-house agents
Amazon is not against agentic shopping; it is against agentic shopping it does not run. Alexa for Shopping launched in May 2026 to research products and make recommendations, and Amazon has since consolidated the Alexa and Rufus assistants into a single shopping feature. The company is also pushing the format beyond the US, a move we examined in Alexa for Shopping’s international hiring signals. Buy for Me, meanwhile, does outbound purchasing on other retailers’ sites.
The commercial ties between Amazon and Meta add an awkward layer. Amazon products have been purchasable inside Facebook and Instagram since 2023, and GeekWire notes that Meta signed a multibillion-dollar agreement in April 2026 to run agentic AI workloads on Amazon’s Graviton chips through AWS. Meta is simultaneously a major cloud customer, a social-commerce partner and, as of this month, an unwanted guest at the Amazon checkout.
What has Amazon done before, and what did the courts say?
Muse is the fourth major AI agent Amazon has moved against. The pattern started with crawlers and escalated to litigation.
| Agent or crawler | Amazon action | Timing | Status |
|---|---|---|---|
| OpenAI (GPTBot, ChatGPT-User, OAI-SearchBot) | Disallowed in robots.txt | Training crawler first, then live fetchers | Blocked; ChatGPT cannot read Amazon product pages |
| Anthropic Claude | robots.txt restriction | Before mid-2025 | Blocked |
| Google AI shopping agents | robots.txt update | Reported by The Information, July 2025 | Blocked |
| Perplexity Comet | Lawsuit under CFAA and California law | Filed November 2025; injunction March 2026 | Injunction vacated August 4, 2026; rehearing denied September 10 |
| Meta Muse | Technical block plus Conditions of Use notice | September 20, 2026 | Blocked; talks ongoing, legal action not ruled out |
Sources: GeekWire, The Register, TipRanks citing The Information, Courthouse News Service.
The crawler blocks were straightforward: Amazon edited its robots.txt file, and for retailers that guide to setting an AI crawler policy is still the relevant playbook. The Perplexity case is different because Comet does not crawl; it logs in as the user and acts. Amazon sued, won a preliminary injunction in March 2026 that kept Comet out of password-protected areas of the store, and then lost on appeal.
The Ninth Circuit’s August ruling
On August 4, 2026 the Ninth Circuit vacated the injunction, holding that Amazon was unlikely to succeed on its Computer Fraud and Abuse Act and California Comprehensive Computer Data Access and Fraud Act claims. The panel reasoned that when a user instructs an agent to act on Amazon.com, it is “the user who ‘accessed’ Amazon’s computers,” not the AI company. On September 10 the court denied Amazon’s request for en banc rehearing, noting in Courthouse News Service’s account that not a single judge “requested a vote on whether to rehear the matter.”
That ruling explains the shape of Amazon’s move against Meta. Amazon did not sue on Sunday night and it did not cite hacking law. It blocked access and pointed to its Conditions of Use, which is exactly the contractual ground the Ninth Circuit left open. Amazon’s remaining claims against Perplexity on remand are breach of terms of service, Lanham Act trademark claims and trespass to chattels. Any future action against Meta would likely travel the same road.
What changes for Amazon sellers and Shopify merchants?
For Amazon’s third-party sellers, nothing changes today and that is the point. Their listings are not reachable by Muse, ChatGPT’s live fetcher or Google’s agents. Discovery on Amazon still runs through Amazon search, Rufus and sponsored placements. Sellers who buy Amazon ads keep the audience they pay for, and sellers who do not remain dependent on Amazon’s organic ranking.
For Shopify merchants, the change is immediate and requires no setup. Any store with Shop Pay enabled is discoverable by Muse by default and can accept a purchase initiated inside the app. A merchant selling on both channels now faces an asymmetry: the same product can be found and bought by an AI agent on the brand’s own Shopify site but not on its Amazon listing. Over time that may pull agent-driven demand toward direct-to-consumer storefronts.
For shoppers the experience is blunt. A Muse user who asks the agent to buy a product on Amazon gets the Conditions of Use error and has to complete the purchase manually in the Amazon app or on the website. The same request pointed at a Shopify brand completes inside Muse with a Shop Pay confirmation. Neither company has said whether Muse will steer users toward retailers where checkout works, but the agent’s design, which searches catalogs it can access, makes that outcome likely by default rather than by policy. A product that the agent cannot buy is, from the agent’s point of view, a product that does not exist.
Three practical checks for merchants this week
- Confirm the Agentic Storefronts channel status in Shopify admin under Sales channels. Meta now appears alongside ChatGPT, Google and Microsoft; merchants who want out have to opt out rather than in.
- Audit product data in Shopify Catalog. Agents match on structured fields, not on hero imagery. Missing weights, variants or shipping rules become invisible products.
- Check chargeback and returns exposure. Shop Pay’s single-purchase credential scoping limits card risk, but a wrong order placed by an agent still generates a return, and the merchant’s policy is what applies.
Is this a protocol fight as much as a retailer fight?
Underneath the Amazon-versus-Shopify headline is a standards contest. Shopify’s Muse integration runs on the Universal Commerce Protocol, which Shopify built with Google and which also carries Gemini and AI Mode purchases. OpenAI’s ChatGPT commerce runs on the separate Agentic Commerce Protocol, developed with Stripe, which launched as Instant Checkout in September 2025 before OpenAI pulled back from the instant model and Shopify said purchases would move inside ChatGPT through Agentic Storefronts.
Meta choosing UCP for Muse is a vote for the Google-Shopify standard over the OpenAI-Stripe one, at least for now. That matters because the operator of the agent decides which protocol it speaks, and the retailer has to support whichever protocol the popular agents use. We laid out in how ACP and UCP could converge or hand off governance why the industry expects consolidation, and Muse’s first two weeks suggest the consumer side of that decision may move faster than the standards bodies.
Amazon, meanwhile, is outside both protocols. It publishes no agent-facing catalog for third parties, and its own agents shop competitors’ sites rather than exposing Amazon’s. An earlier shopappy analysis asked whether Amazon would open its marketplace to external agents before the holidays; the Muse block is the strongest evidence yet that the answer for 2026 is no.
The consequences of Amazon’s crawler policy already show up in rival assistants. Because Amazon disallows OpenAI’s ChatGPT-User and OAI-SearchBot fetchers alongside the GPTBot training crawler, ChatGPT cannot read live Amazon product pages, prices, specifications or reviews, as eMarketer and others have noted. Any assistant that relied on Amazon’s catalog for recommendations has had to fall back on retailers that publish structured feeds. Muse’s block extends that logic from reading to buying: Amazon has now walled off both the information an agent needs to recommend a product and the checkout it needs to complete the sale.
Could regulators get involved?
No regulator has commented on the Muse block, and there is no indication of a formal complaint. But the episode lands in a crowded field. Senators Tammy Baldwin and Rick Scott asked the Federal Trade Commission last week to examine whether Amazon’s and Walmart’s shopping AIs suppress Made in USA products, and the FTC signaled this month that it intends to scrutinize personalized pricing practices. Both show the agency is already thinking about how AI intermediaries shape what consumers see and pay.
The Ninth Circuit’s framing, that the user is the one accessing the site, also cuts in a direction that could interest antitrust enforcers. If a consumer has the legal right to use a tool of their choice to shop, a dominant retailer’s blanket block on every non-Amazon tool becomes a question about consumer choice rather than computer security. Amazon’s position is that a customer agreed to the Conditions of Use and that those conditions bar unauthorized agents. Whether that contract term survives scrutiny if agents become the default way people shop is untested.
There is a consumer-protection dimension as well. Amazon’s stated concern about credential capture is the kind of issue the FTC has historically treated seriously, and Meta’s assurance that Muse cannot see passwords is a claim that could be examined under the agency’s authority over deceptive practices if it proved inaccurate. At the same time, a large platform using security language to justify excluding a competitor’s product is a pattern regulators on both sides of the Atlantic have learned to look at twice. Both companies have an interest in keeping the dispute commercial rather than inviting that examination.
In Europe the picture is different again. The Digital Markets Act obliges gatekeepers to allow interoperability in several contexts, and the European Commission has shown this month, with Google’s removal of free product listings across the EEA under a DMA compliance deadline, that it is willing to force structural change in how shopping surfaces work. Amazon is a designated gatekeeper for its marketplace. If Muse launches in the EU, an Amazon block there would be tested against DMA rules rather than only against US contract law.
What should retailers and investors watch next?
The immediate signal is whether Amazon and Meta reach an arrangement. Amazon says the two companies are talking directly. A deal would probably look like the one Amazon says it offers other brands through Buy for Me: the agent identifies itself, the retailer opts in, and the retailer keeps its own checkout. Meta’s incentive to accept that is limited while Muse is growing without Amazon, and Amazon’s incentive to concede is limited while its ad business is intact.
Watch three dates and data points:
- Muse’s next Sensor Tower reading. If downloads keep pace with ChatGPT’s launch curve, Amazon is blocking a mass-market app rather than a niche tool, and the customer-service cost of “your agent doesn’t work here” rises.
- Any Amazon filing against Meta. A contract or Lanham Act suit would follow the post-Perplexity template; its absence would suggest Amazon prefers negotiation.
- Shopify’s third-quarter commentary. Shopify’s next quarterly report is due in the autumn. Any disclosure of agent-originated GMV or Shop Pay volume through Muse, ChatGPT or Gemini would be the first hard number on whether agentic checkout is moving sales rather than press releases.
Holiday timing sharpens all of this. Amazon’s Prime Big Deal Days run October 6 and 7, and the Bain forecast for the first trillion-dollar US holiday season assumes online growth well ahead of stores. If millions of Muse users find that their agent can buy from a Shopify brand but not from Amazon during the biggest shopping weeks of the year, the block stops being an industry story and becomes a consumer one.
Frequently asked questions
When did Amazon block Meta’s Muse agent?
The block took effect on Sunday night, September 20, 2026, according to GeekWire and TechCrunch. Users attempting purchases through Muse began seeing a message that continued access by an unauthorized AI agent violates Amazon’s Conditions of Use.
What reasons did Amazon give?
Amazon said Meta did not disclose that Muse would access Amazon.com, did not obtain authorization, and that the agent does not identify itself as automated and appears to capture and store customer credentials. An Amazon spokesperson said third-party purchasing applications should “operate openly and respect service provider decisions about whether or not to participate.”
What did Meta say in response?
Meta said Muse “has no visibility into people’s passwords or payment methods” and that credentials are held in secure storage so the agent can use them without seeing them. Meta declined to comment further to several outlets.
What did Shopify announce?
Shopify CEO Tobi Lütke said on Monday, September 21 that Shopify is partnering with Muse to enable agentic checkout with Shop Pay on all Shopify stores. Purchases run through the Universal Commerce Protocol, and Shopify merchants are discoverable in Muse by default.
Does the Perplexity court ruling apply to Meta?
Not directly, but it shapes Amazon’s options. In August 2026 the Ninth Circuit held that a user, not the AI company, is the party accessing Amazon’s computers when an agent shops on the user’s instruction, so anti-hacking claims are unlikely to succeed. Amazon retains contract, trademark and trespass claims, which is why its Muse block cites the Conditions of Use rather than hacking law.
How popular is Muse?
Sensor Tower data reported by CNBC put Muse at about 2.5 million app downloads in its first 13 days, compared with about 3.1 million for ChatGPT over a comparable window. Muse became the No. 1 free iOS app in the US within a week of its September 8 launch.
Can Amazon sellers make their products available to Muse?
Not through Amazon. The block applies to the whole Amazon.com storefront. Sellers who also run a Shopify store with Shop Pay are reachable by Muse through that channel.
Does Amazon have its own AI shopping agent?
Yes. Alexa for Shopping launched in May 2026 for research and recommendations, and Amazon has merged it with Rufus. Buy for Me is Amazon’s outbound agent that purchases from other retailers’ websites, identifies itself and lets those retailers opt in or out.
What should a Shopify merchant do now?
Check the Agentic Storefronts channel in Shopify admin to confirm whether Meta is enabled, make sure product data in Shopify Catalog is complete, and review returns and chargeback policies for orders placed by agents. No setup is required for Muse checkout itself.