A US court has granted Amazon a preliminary injunction against Perplexity, marking a legal escalation in a dispute that began over control of AI-driven checkout experiences.
Amazon has secured a preliminary injunction against Perplexity, escalating a dispute which began with a cease-and-desist letter into a broader legal test over how AI agents can interact with online platforms.
In an order issued on 9 March, the US District Court for the Northern District of California granted Amazon’s request to block Perplexity’s Comet browser agent from accessing its systems, at least while the case proceeds. The ruling marks the first substantive judicial intervention in a case that has drawn attention across payments, e-commerce, and AI.
The dispute centres on whether AI agents acting on behalf of users can autonomously access and transact within digital platforms, or whether that access remains subject to platform-level control.
From cease and desist to courtroom
The legal action follows Amazon’s cease and desist letter in October 2025, which alleged Comet had accessed the Amazon Store without transparent identification, degraded the customer experience and breached computer misuse laws.
At the time, Amazon argued third-party applications making purchases on behalf of users should operate openly and respect a platform’s decision on participation. Perplexity rejected that framing, positioning its technology as an extension of user choice and control.
The dispute has now moved beyond competing narratives into a legal determination of how such systems operate within existing frameworks.
In granting the injunction, Judge Maxine Chesney found Amazon had shown a likelihood of success on key claims, including under the Computer Fraud and Abuse Act.
The court accepted Amazon’s argument that Perplexity’s Comet agent accessed password-protected areas of its platform without authorisation, even where end users had granted permission. According to the ruling, the agent was able to navigate Amazon accounts, retrieve private user data and transmit that information back to Perplexity’s systems.
The judge also pointed to evidence that Amazon had incurred costs exceeding $5,000 in responding to the activity, including efforts to detect and block the agent’s access .
Importantly, the court drew a distinction between user consent and platform authorisation, finding that permission from users did not override Amazon’s ability to restrict access to its systems.
Injunction restricts access and requires data deletion
The order places immediate restrictions on how Perplexity can operate its Comet agent in relation to Amazon.
Perplexity is prohibited from accessing Amazon’s protected systems using AI agents or facilitating such access through user accounts. It is also required to delete any Amazon data obtained through those interactions and confirm compliance.
The court found that Amazon would face irreparable harm without intervention, citing the likelihood that the conduct would continue in the absence of an injunction.
While Perplexity argued that the restrictions would damage its position in the emerging AI-assisted shopping market, including its ability to iterate on the Comet product, the court concluded that the balance of hardships favoured Amazon.
Appeal filed as case moves to Ninth Circuit
Perplexity filed a notice of appeal on 10 March, seeking to challenge the preliminary injunction in the US Court of Appeals for the Ninth Circuit.
The district court declined to grant a stay pending appeal but allowed a limited seven-day administrative stay to give Perplexity time to seek relief from the appellate court.
The appeal means the case will now move into a higher court review, with the underlying legal questions remaining unresolved.
When the dispute first emerged, it was framed as a question of “who controls execution at checkout”. The latest ruling does not settle that question, but it does clarify how existing laws may be applied to AI-driven interactions.
