What did the Ninth Circuit actually rule on August 4, 2026?

The Ninth Circuit Court of Appeals reversed a preliminary injunction that had barred Perplexity's Comet browser agent from operating on Amazon.com. [1] The panel held that when Comet completes a purchase on a user's instruction, it is the user — not Perplexity — who "accesses" Amazon's platform, so Amazon's claim under the Computer Fraud and Abuse Act was unlikely to succeed. [2] It's one of the first federal appeals rulings to address the question directly.

Does this mean any AI agent can now legally access any website without permission?

No. The ruling only addresses one legal theory — unauthorized access under the federal Computer Fraud and Abuse Act — and only reverses a preliminary injunction, not a final judgment; the underlying case continues, and Amazon says it's "evaluating its next steps." [2] Contract-based claims (terms of service), technical blocking, and claims outside the Ninth Circuit's jurisdiction aren't resolved by this decision.

Can I still block AI shopping agents from my site with robots.txt or a firewall rule?

Technically, yes — this ruling is about what counts as illegal "access" under a specific hacking statute, not about your right to configure your own servers. But the practical value of blocking has dropped: the ruling removes one of the legal backstops platforms used to enforce those blocks against agents acting on a real user's instruction, per legal commentary on the decision. [3] Pair technical controls with an explicit, contract-based agent policy rather than relying on the CFAA to do the enforcement for you.

How is this different from the agentic commerce protocols (ACP, UCP) I keep hearing about?

ACP and UCP are voluntary technical standards that let a merchant hand structured product and checkout data directly to an AI agent. [5] This ruling is about what happens when there's no such agreement — an agent like Comet navigating a site the old-fashioned way, by rendering and interacting with pages, without the merchant's cooperation. The court just made that second path meaningfully harder to shut down with a lawsuit.

Does this apply outside the United States?

The ruling is US law and binds only the Ninth Circuit (the western US federal circuit, including California). It isn't controlling precedent elsewhere, but because most major AI agents (Perplexity, OpenAI, Google) are US companies litigating principally in US courts, expect it to shape how those companies argue agent-access cases globally, and to be cited as persuasive authority in other jurisdictions weighing similar disputes.

Amazon Just Lost Its Legal Shield Against AI Shopping Agents: What the Perplexity Ruling Means for Your Site

A Ninth Circuit Court of Appeals panel ruled on Tuesday, August 4, 2026 that Perplexity's Comet AI agent did not violate federal hacking law by shopping on Amazon on its users' behalf, reversing a preliminary injunction Amazon had won in March 2026.^[1] It's one of the first federal appeals court rulings to address whether an AI agent acting on a user's instruction can legally browse, click, and buy on a website that doesn't want it there^[2] — and it lands squarely on top of the same question every business now optimizing for AI visibility has to answer: what happens when an AI agent shows up at your site uninvited?

Key Facts at a Glance

Detail	Finding	Source
Ruling date	Tuesday, August 4, 2026	Bloomberg Law ^[1]
Court	US Court of Appeals for the Ninth Circuit	Bloomberg Law ^[1]; NewsBytes ^[4]
What was reversed	A March 2026 preliminary injunction barring Perplexity's Comet browser from Amazon.com	PYMNTS ^[2]
Legal theory at issue	Computer Fraud and Abuse Act (CFAA) — "unauthorized access"	Bloomberg Law ^[1]; NewsBytes ^[4]
Core holding	An agent acting on a user's instruction is the user, not the AI company, "accessing" the site	PYMNTS ^[2]; The Next Web ^[3]
Amazon's response	"We respectfully disagree" — "evaluating our next steps"	PYMNTS ^[2]
Status	Preliminary-injunction reversal; underlying case continues at the district court	PYMNTS ^[2]

What Did the Ninth Circuit Actually Decide?

The dispute started in March 2026, when a federal district court sided with Amazon and issued a preliminary injunction against Perplexity's Comet browser. The district judge found Amazon had presented "strong evidence" that Comet accessed Amazon's site without authorization and showed "a likelihood of success on the merits" of its CFAA claim, which was enough to block Comet from Amazon.com while the case proceeded.^[2]

On appeal, the Ninth Circuit reversed. The panel's reasoning turns on a single question the CFAA has never cleanly answered: when software acts on a person's direct instruction, who is doing the "accessing"? The court concluded it's the person. As one legal summary of the ruling put it, "an agent acting on a user's instruction is the user, not Perplexity, who is accessing Amazon's servers."^[3] Because Comet works by taking screenshots of Amazon's pages and acting on them at the user's direction — pointing it at a product lets it navigate Amazon and complete a purchase — the court found no unauthorized access by Perplexity itself.^[3]

Perplexity, which had called Amazon's suit a "bald attempt" to keep Comet's users off the platform, argued that its agent simply does on a user's behalf what the user could do manually — and framed Amazon's real objection as commercial rather than security-related: AI agents don't see the on-site advertising Amazon shows human shoppers, which Perplexity argued was the suit's real motivation.^[4] Amazon's statement after the ruling was brief and unresolved: "We respectfully disagree with today's decision on the preliminary injunction," adding that it remains "confident in our case" and is "evaluating our next steps."^[2] That leaves the underlying CFAA claim alive at the district court — this ruling lifts the injunction, it doesn't end the lawsuit.

Does This Mean Any AI Agent Can Now Access Any Website?

No — and this is the distinction worth getting right before you change anything about your own site. Three limits matter:

It's one legal theory, not every legal theory. The ruling addresses only the CFAA's "unauthorized access" language. It says nothing about breach-of-contract claims under a site's terms of service, copyright claims over scraped content, or other legal avenues a platform could still pursue against an agent that ignores an explicit ban.
It's a preliminary ruling, not a final one. The case goes back to the district court on the merits. Amazon hasn't dropped its claim — it's still deciding how to respond.^[2]
It's binding in one circuit. The Ninth Circuit covers the western US federal courts; the ruling isn't controlling precedent in other circuits, though it will likely be cited as persuasive authority anywhere a similar dispute lands.

What the ruling does change is more practical than absolute: it removes one of the sharpest legal tools a platform had for keeping third-party agents out by force of lawsuit, and it puts real pressure on business models — like retail media, sponsored placements, and controlled on-site experiences — that depend on a platform being able to dictate exactly how visitors interact with its pages.^[3]

What This Means for Your Own AI-Agent Strategy

If your business has a website, this ruling is a signal to stop treating "AI agents visiting my site" as a hypothetical edge case. Two tracks are now live simultaneously, and this decision tilts the balance toward the second one:

Block-and-litigate got weaker. Relying on a CFAA claim to keep unwanted AI agents off your site just got harder to win, at least on the "unauthorized access" theory Amazon tried and lost. A robots.txt disallow or a bot-detection rule is still a legitimate technical control, but the legal backstop behind it — "and if they ignore it, we sue for hacking" — is now a weaker bet in the Ninth Circuit, and untested everywhere else.

Structured cooperation is the stronger lever. The alternative to fighting agents at your door is giving them a sanctioned front door instead: an llms.txt file describing your site and offerings in a format models can consume directly, and support for agentic-commerce protocols like ACP (OpenAI's protocol, adopted by Shopify, Etsy, and Walmart) and UCP (Google's competing protocol) that hand an agent structured catalog and checkout data instead of forcing it to screen-scrape your pages the way Comet does on Amazon.^[5] That's the same infrastructure covered in how ChatGPT decides what to cite and in what changes when AI, not a ranking algorithm, answers the query — this ruling is a legal argument for building it sooner rather than later.

Put simply: the businesses now most exposed are the ones with no agent policy at all — no llms.txt, no stated terms for agentic access, and no visibility into whether agents are already hitting their site the way Comet was hitting Amazon's.

What Should You Do This Week?

Check your server logs for agent traffic you haven't accounted for — user-agent strings for Comet, ChatGPT Atlas, and similar agentic browsers are a starting point, though many agents don't identify themselves cleanly.
Write (or review) an llms.txt that states plainly what your site is, what you sell, and what an agent is and isn't allowed to do — don't leave that determination to a CFAA claim you might not win.
Decide your agentic-commerce posture now, not reactively — if you sell anything online, figure out whether ACP, UCP, or both are worth supporting before agent traffic becomes large enough that ad hoc blocking is your only defense.
Separate "technical control" from "legal control" in your thinking. This ruling didn't take away your ability to configure your own servers — it weakened one specific lawsuit you could bring if someone ignores that configuration.
Track how AI agents already describe and reach your business across ChatGPT, Perplexity, Gemini, and Google AI Overviews — not just whether they can technically access your site, but whether they're recommending it in the first place. Our Multi-Engine Visibility platform and llms.txt setup and maintenance exist specifically for this gap.

This ruling doesn't resolve where agentic access law is headed — Amazon is still deciding its next move, and the underlying case isn't over.^[2] What it does confirm is that "block and hope the law backs me up" is no longer a strategy you can count on by default. The businesses that come out ahead will be the ones that treat AI agents as a traffic source to architect for, the same way they already architect for search crawlers and human visitors.

See where you stand in AI search. Run a free AEO audit of your site — free with a 3-month plan minimum.

References

[1] Bloomberg Law, "Perplexity Overturns Amazon Ban on AI Shopping Bot on Appeal," August 4, 2026. https://news.bloomberglaw.com/us-law-week/perplexity-overturns-amazon-ban-on-ai-shopping-bot-on-appeal — court name (Ninth Circuit), ruling date, CFAA framing, and the ruling's practical effect of letting Comet resume operating on Amazon.com.

[2] PYMNTS, "Appeals Court Overturns Ban on Perplexity AI Shopping Agents on Amazon," August 2026. https://www.pymnts.com/amazon/2026/appeals-court-overturns-ban-on-perplexity-ai-shopping-agents-on-amazon/ — details of the March 2026 district-court injunction, the "it was Perplexity's users, not Perplexity itself" holding, and direct quotes from Perplexity and Amazon.

[3] The Next Web, "Court lets Perplexity's AI agent shop on Amazon, overturning a ban," August 2026. https://thenextweb.com/news/amazon-loses-perplexity-comet-ai-shopping-ruling — the "agent acting on a user's instruction is the user" quote, the "sharpest tools for keeping third-party agents out" framing, and the retail-media-economics implications.

[4] NewsBytes, "Amazon loses court battle to block Perplexity's AI shopping tools," August 5, 2026. https://www.newsbytesapp.com/news/science/amazon-loses-court-battle-to-block-perplexity-s-ai-shopping-tools/story — confirmation of the Ninth Circuit as the deciding court, the "bald attempt" quote, and Perplexity's argument that Amazon's suit was motivated by advertising exposure rather than security.

[5] Search Engine Journal, "Agentic Commerce: What SEOs Need To Consider (ACP & UCP)." https://www.searchenginejournal.com/agentic-commerce-what-seos-need-to-consider-acp-ucp/563503/ — confirms ACP as OpenAI's protocol (launched with Stripe) and UCP as Google's, and Shopify/Etsy/Walmart's adoption of ACP.