Amazon has gained the upper hand in a legal fight against an AI shopping agent. A U.S. federal judge issued an injunction blocking AI search startup Perplexity from accessing Amazon’s site without authorisation through its Comet AI browser, CNBC reported on Tuesday.

Perplexity used Comet to let users search for and buy products on Amazon, but Amazon judged it to be an unauthorised activity.

U.S. District Judge Maxine Chesney issued the injunction after finding Amazon spent more than $5,000 to block Perplexity’s unauthorised access and staff invested significant time developing response tools, and that Amazon was likely to win, CNBC reported.

Amazon spokesperson Maxine Tagay said it was an "important measure to maintain a trusted shopping experience" and welcomed the court decision. Perplexity, meanwhile, said it would "fight to protect users' right to choose the AI they want."

Amazon argued Perplexity's AI agent threatened customer data security and also caused problems for its advertising system. It said if AI generates advertising traffic, work is needed to detect and filter it, making it difficult to maintain contracts with advertisers.