Amazon v. Perplexity AI is a lawsuit in which Amazon.com, Inc. seeks to bar Perplexity AI, Inc.'s Comet AI shopping agent from accessing Amazon's marketplace under unauthorized-access theories. Amazon filed in November 2025; on March 9, 2026 the U.S. District Court for the Northern District of California granted Amazon a preliminary injunction; Perplexity appealed to the Ninth Circuit on April 1, 2026, and on August 4, 2026 a Ninth Circuit panel vacated the injunction and remanded. It is among the first cases to apply Computer Fraud and Abuse Act (CFAA) and authorization theories to an AI agent that transacts on a user's behalf rather than merely extracting data.
| Field | Detail |
|---|---|
| Plaintiff | Amazon.com, Inc. |
| Defendant | Perplexity AI, Inc. |
| Court | U.S. District Court, Northern District of California (Judge Maxine Chesney); preliminary injunction vacated by the Ninth Circuit on August 4, 2026 and remanded; rehearing denied September 10, 2026 (per press reports) |
| Filed | November 2025 |
| Status | Active. Preliminary injunction granted March 9, 2026; appeal argued June 11, 2026; Ninth Circuit vacated the injunction and remanded on August 4, 2026; Amazon petitioned for rehearing en banc on August 18, 2026; rehearing denied September 10, 2026 (per press reports) |
Background
The dispute concerns Perplexity's Comet AI shopping agent and its access to Amazon's website. Amazon's competing shopping AI is Rufus.
Claims
Amazon alleges that Comet accessed Amazon's website without authorization, and that Perplexity disguised Comet's automated traffic as ordinary Google Chrome browser sessions to evade detection. Its theories are:
- Unauthorized access — Amazon's terms of service prohibit automated scraping, and Comet's agent activity continued after Amazon objected.
- Fraudulent concealment — Perplexity allegedly modified Comet to mimic human Chrome traffic rather than transparently identifying as an AI agent.
- Security and integrity risks — Amazon argues that unverified agent traffic poses fraud, abuse, and customer-confusion risks.
Perplexity responds that Amazon's true motive is competitive: Comet bypasses the advertising shown to human shoppers, threatening Amazon's ad-revenue model and competing with Amazon's own Rufus shopping AI. Perplexity also argues that the user, not Perplexity, directs the agent, and that Comet acts on behalf of an authenticated Amazon customer using their own credentials. It contends that blocking the agent harms users' ability to delegate routine purchasing to AI assistants.
Procedural history
Amazon filed the suit in November 2025. On March 9, 2026, Judge Maxine Chesney (N.D. Cal.) granted a preliminary injunction, finding "strong evidence" that Comet accessed Amazon "at the user's direction" but "without authorization" from Amazon, and enjoining Comet from accessing Amazon's marketplace (Source: cnbc.com; bloomberg.com). On April 1, 2026, Perplexity appealed to the Ninth Circuit, seeking to overturn the preliminary injunction (Source: pymnts.com).
The Ninth Circuit heard oral argument on June 11, 2026, weighing how the Computer Fraud and Abuse Act applies to AI agents that browse on a user's behalf; the district court had found Perplexity violated the CFAA and California's analogous statute by continuing to access Amazon's systems after a cease-and-desist letter (Source: laweconcenter.org).
On August 4, 2026, a Ninth Circuit panel of Circuit Judges Milan D. Smith, Jr. and Eric C. Tung and District Judge John Charles Hinderaker, sitting by designation, issued a published opinion by Judge Smith vacating the preliminary injunction and remanding for further proceedings (Amazon.com Services, LLC v. Perplexity AI, Inc., No. 26-1444 (9th Cir. Aug. 4, 2026) — Opinion). An August 7 news account gave the date as August 5; the slip opinion is dated August 4, 2026, and that date governs (Source: reuters.com). Legal commentary in the same account distinguishes the case from the model-driven intrusions disclosed by frontier developers in July 2026 on the ground that it involves agents acting on behalf of human users rather than fully autonomous models.
The panel held that Amazon was unlikely to succeed on the "access" element of either statute. Because the Assistant runs on the user's machine and Perplexity's servers "never directly access Amazon's servers" — a description the panel drew from the amicus brief of the Electronic Frontier Foundation, the Alliance for Responsible Data Collection, Mozilla, Digital Medusa and EleutherAI — Perplexity "does not directly communicate with Amazon's servers." Nor does Perplexity access those servers through the Assistant: § 1030(a)(2) punishes "[w]hoever . . . intentionally accesses" a protected computer, and "[h]owever advanced the Assistant currently is, it is a tool, not a person for statutory purposes." It is therefore "the user who 'accesses' Amazon's computers, with the help of the Assistant to carry out specific acts on Amazon.com." The rule of lenity reinforced that reading, the panel said, because Amazon's interpretation "could expose users themselves to criminal liability (under a conspiracy or aiding-and-abetting theory)." The CDAFA claim failed for the same reason: while "Amazon might be correct that 'access' under the CDAFA is broader than the CFAA's definition, the focus of the inquiry is still on the person accessing or causing the access."
The panel also held that the remaining equitable factors favored Perplexity. Amazon's evidence of a degraded shopping experience was "more attenuated than the harms recognized in other 'threat of harm' cases," and its cyber-risk showing was "limited and counteracted, at least in part, by Perplexity's asserted cyber improvements"; the balance of equities and the public interest both weighed against enjoining conduct that likely violates neither statute. The opinion states its own limits: it does "not establish a new legal regime governing agentic AI," does not address tort or other theories, reserves whether a different record could show Perplexity exercising control amounting to entry, and does not "impair Amazon's ability to regulate access to Amazon.com via private terms of service for its users."
Amazon petitioned for rehearing en banc on August 18, 2026, under Fed. R. App. P. 40(b)(2)(A) and (D), asking that the opinion be vacated and the preliminary injunction reinstated (Petition for Rehearing En Banc — Amazon.com Services LLC v. Perplexity AI, Inc. (9th Cir., August 18, 2026); Source: metnews.com). The petition frames the case as one about appellate standards rather than AI doctrine: because the panel did not find that the district court applied the wrong legal rule, Amazon argues it could reverse only for abuse of discretion under United States v. Hinkson, a standard the panel "recited . . . but never applied," instead resolving the appeal on a block quote from an amicus brief the district court never saw, contrary to United States v. Sineneng-Smith. Amazon accepts the panel's inference on the panel's own premises — "If those were the only facts, that conclusion might follow" — and disputes the premises, pointing to district-court findings that the Assistant "spins and is unable to perform any actions" when cut off from Perplexity's servers, that Perplexity supplies the "reasoning layer," that a generic request such as "order paper towels" causes Perplexity to direct the Assistant into the store using stored credentials in sessions that "started without the user visiting amazon.com," and that the Assistant transmits the user's full browsing history "regardless of the webpage in the current tab and the user's request."
Three further grounds follow. The petition argues the panel declined to follow Facebook v. Power Ventures on the ground that it merely "implied" access, where that decision "explicitly said that 'Power accessed Facebook's computers.'" It argues the rule of lenity is "solely a principle of statutory interpretation" and was used here "as a factual tiebreaker for whether the evidence was sufficient," and that the panel's concern about exposing users to criminal liability is answered by Rosemond v. United States on aiding-and-abetting intent and by Gebardi v. United States, Nosal and Brekka, which place authorized users outside the CFAA — "the gates are up for customers and down for Perplexity." On the state claim, it argues the panel quoted Cal. Penal Code § 502(b)(1) only in part, omitting the verbs "instruct" and "communicate with," which "describe what the panel acknowledged Perplexity instructs the Assistant to do," and collapsed an independent state ground into the narrower federal one contrary to United States v. Christensen. Amazon states it "is confident that it will eventually prevail under the standard set forth by the panel," so the asserted harm is interim rather than doctrinal (Petition for Rehearing En Banc — Amazon.com Services LLC v. Perplexity AI, Inc. (9th Cir., August 18, 2026)).
The Software & Information Industry Association filed an amicus brief supporting that petition on August 28, 2026, announced August 31 (Brief of the Software & Information Industry Association as Amicus Curiae Supporting Rehearing En Banc — Amazon v. Perplexity (August 28, 2026); Source: siia.net; insideaipolicy.com). SIIA argues that the panel neither credited the district court's control findings nor held them clearly erroneous under United States v. Hinkson; that it narrowed Facebook v. Power Ventures, which SIIA reads as having already resolved the intermediary-access question, without saying so; that the resulting rule makes liability turn on "where the code runs rather than on what the operator did," which would leave the same circumvention "unlawful when carried out by ordinary software and lawful when carried out by an agentic AI tool"; and that the panel folded the CDAFA claim into the narrower federal statute, contrary to United States v. Christensen. The brief states that SIIA's member AI developers "already build to the agent identification and permissioning standards emerging across the industry — including the Agentic Commerce Protocol ('ACP')" developed by OpenAI and Stripe "and the Model Context Protocol ('MCP')" developed by Anthropic, and are "disadvantaged by Perplexity's evasive conduct." The positions are those of a trade association whose members compete with Perplexity, not findings of the court.
Other amici at the merits stage included the American Civil Liberties Union and the Knight First Amendment Institute, the Electronic Frontier Foundation with Mozilla, Digital Medusa and EleutherAI, the National Retail Federation, Digital Context Next, the News/Media Alliance, and Airlines for America (Amazon.com Services, LLC v. Perplexity AI, Inc., No. 26-1444 (9th Cir. Aug. 4, 2026) — Opinion).
Current status
The preliminary injunction granted on March 9, 2026 was vacated by the Ninth Circuit on August 4, 2026, and the case remanded to the Northern District of California for further proceedings (Amazon.com Services, LLC v. Perplexity AI, Inc., No. 26-1444 (9th Cir. Aug. 4, 2026) — Opinion). Amazon's petition for rehearing en banc, filed August 18, 2026 as docket entry 66, was pending as of September 4, 2026, with amicus support from SIIA (Petition for Rehearing En Banc — Amazon.com Services LLC v. Perplexity AI, Inc. (9th Cir., August 18, 2026); Source: siia.net). No ruling on the petition has been recorded, and no order calling for a response appears on the appellate docket through September 4, 2026.
The Ninth Circuit denied rehearing on September 10, 2026, according to reporting on Amazon's subsequent dispute with Meta; the order itself has not been retrieved. After the ruling, Amazon blocked Meta's Muse agent from its store on September 20, 2026 on the basis of its Conditions of Use rather than any hacking claim (Sources: geekwire.com; axios.com).
Commentary
Observers describe the case as the first major test of CFAA and authorization theories applied to agentic AI. Prior scraping cases such as hiQ v. LinkedIn and Van Buren v. United States tested whether automated access exceeds authorization for data extraction; Amazon v. Perplexity extends the question to transactional agent activity, such as placing orders. Perplexity's user-direction defense raises the question of whether the user or the agent vendor is the relevant access principal for agent-mediated activity; commentators note that if the Ninth Circuit accepts the user-as-principal framing, the holding would limit a site operator's ability to block agentic traffic through terms of service alone. The same agent-routing question is expected to recur for travel sites, ticketing platforms, and other commercial sites. Commentary also frames the dispute as the agentic-era counterpart to earlier browser-extension and price-comparison-tool disputes over whether software can act on a user's behalf inside a commercial site, and, in light of Perplexity's argument that Amazon is protecting ad revenue from agent disintermediation, as an antitrust-adjacent dispute over who captures e-commerce surplus.
The appellate record is now anchored on the published opinion, Amazon's rehearing petition and the SIIA brief, all retrieved from primary hosts. The district-court orders of March 2026 have still not been retrieved, and the account of the trial-court stage remains triangulated from CNBC, Bloomberg, GeekWire, Retail Dive, and IAPP coverage; the district court's language is known only as quoted in the panel opinion.
Relationships
- supports: Amazon.com Services, LLC v. Perplexity AI, Inc., No. 26-1444 (9th Cir. Aug. 4, 2026) — Opinion — the published panel opinion, the primary record of the appellate stage.
- contradicts: Brief of the Software & Information Industry Association as Amicus Curiae Supporting Rehearing En Banc — Amazon v. Perplexity (August 28, 2026) — trade-association brief arguing the panel opinion should be reheard en banc.
- contradicts: Petition for Rehearing En Banc — Amazon.com Services LLC v. Perplexity AI, Inc. (9th Cir., August 18, 2026) — Amazon's petition seeking vacatur of the panel opinion.
- depends-on: AI Agentic Browsers, Computer Fraud and Abuse Act (CFAA), Perplexity, Amazon.
- litigates: Software & Information Industry Association (SIIA) (amicus at the merits stage and in support of rehearing en banc); Electronic Frontier Foundation (EFF) (amicus whose description of the Comet architecture the panel adopted).
- related: Agentic Commerce Protocol (ACP), Model Context Protocol (MCP) — the agent-identification standards SIIA's brief invokes; browser-extension and scraping precedents (hiQ v. LinkedIn; Van Buren v. United States); Amazon's Rufus shopping-AI product.