Amazon.com Inc. is suing Perplexity AI Inc. to try and stop the startup from helping users buy items on the world’s largest online marketplace, setting up a showdown that may have implications for the reach of so-called agentic artificial intelligence.

On Monday, Amazon announced a partnership that will allow OpenAI to use the company’s cloud computing services to run AI systems for products like the popular ChatGPT. OpenAI is paying $38 billion to access Amazon Web Services (AWS) servers and “hundreds of thousands of state-of-the-art NVIDIA GPUs.”