Amazon blocks Meta's Muse agent while Walmart opens an MCP gateway for AI shoppers

Two of the largest US retailers have taken opposite positions on autonomous shoppers. In September 2026 Amazon began blocking an AI shopping agent from its site; in October Walmart announced infrastructure designed to let exactly that kind of agent in.

Amazon's gate is a contract

According to a dev.to write-up citing an Amazon spokesperson, Amazon began blocking Meta's Muse agent from Amazon.com on the night of Sunday 20 September 2026. Amazon says it had asked Meta to remove Amazon from the Muse experience, and shoppers who try to use Muse on the site now see a pop-up telling them it violates Amazon's terms of use.

The notable part is the mechanism. The lever is contract rather than a new technical wall: Amazon sets what its terms allow, and an agent that does not fit is in breach. The dev.to author's reading is that Amazon is protecting the right to decide who may act on its site — whether the agent can complete a purchase is not the question.

It fits a pattern. In 2025 Amazon sued Perplexity AI, arguing the company concealed its shopping agents after Amazon had asked it to remove them.

Walmart builds a front door for agents

Walmart went the other way. At the Masters of Scale Summit in San Francisco on 21 October 2026, CEO John Furner announced Agent Gateway, designed to let approved agents connect to Walmart over the Model Context Protocol. An agent using the gateway can search Walmart's online inventory and make purchases for its user, with support for both Walmart and Sam's Club. The dev.to post says its Walmart details come from TechCrunch's coverage of the announcement.

Nor is it a single-partner arrangement. Walmart has a partnership with Meta's Muse — the same agent Amazon blocks — plus integrations with ChatGPT, Gemini and other AI apps.

For developers, the MCP detail is the point: instead of driving a website with a headless browser, an agent connects to a server that exposes defined tools. The retailer decides what checkout requires, and a rejected call is a result the code handles, not a crash.

Agents get their own identities

Alongside the gateway, Walmart announced Agent Profiles: dedicated profiles inside a customer's account, shown separately from the customer's own purchases, rolling out in November 2026. A profile is created the first time a customer uses a given agent through the gateway; a Walmart account is required, Walmart+ is not.

Customers can require approval for each transaction, set a spending limit for the agent's profile, and delete it at any time. Walmart compares this to adding an authorized user to a credit card — a distinct, capped party acting for the customer rather than the customer. The dev.to author cautions that the feature is announced, not live, and details may change before rollout.

Walmart blocks too — on behaviour

Opening the door does not mean leaving it unguarded. Walmart's terms for AI agents say agents cannot act beyond the shopper's intent, cannot access payment information, and may only access the information a task requires; agents that do not comply will be blocked from the site.

The contrast, as the dev.to post draws it, is the trigger. At Amazon the Muse block turned on the agent's presence under the terms of use; at Walmart the trigger is behaviour — over-reach, touching payment data, taking more data than needed. Walmart also says customers can shop their usual brands without sharing personal information or purchase history directly with the agent, and that its returns process applies even when an agent does not act as intended.

Zuckerberg bets against the blockers

Meta's position is blunt. Speaking on a podcast with Stripe's John Collison, reported by Payments Dive on 15 October 2026, Mark Zuckerberg said “very few really” have tried to block Meta's agent integration and predicted that blocking “will end up not being the right strategic thing for them”. As the dev.to author notes, Zuckerberg is an interested party — Meta's agent is the one being blocked — and whether terms-based blocking holds over time is an open question.

Why it matters

Both retailers are preparing for AI agents to shop; the disagreement is over who owns the door. Amazon is betting it can decide which agents act on its site, with its terms of use and the courts as the instrument. Walmart is betting it can let many agents in as long as money, identity and the returns path stay with Walmart and the customer, enforced through MCP tools, per-agent profiles and behavioural rules.

For agent builders, each position has a price: a blocking retailer can shut you out regardless of how well your agent behaves, while an inviting one imposes limits on data, spending and identity. The dev.to post's advice holds either way — prefer an approved, authenticated interface over scraping, never touch payment credentials, request the minimum data, and build per-transaction approval and spending caps in from the start.