When AI agents can autonomously access platforms and complete transactions on behalf of users, who should bear legal liability for their conduct: the developers, the users, or the platforms? Two landmark events in late 2025 – the Amazon v. Perplexity lawsuit in the United States and the platform bans on the Doubao AI Phone in China – reveal the urgency and complexity of this question through starkly different approaches to liability attribution. This article systematically examines the legal frameworks in the United States, the European Union, and China, finding that traditional agency law, product liability law, and computer fraud law struggle to effectively address liability allocation for AI agents. On this basis, this article proposes a tripartite liability allocation framework, advocating for dynamic liability allocation among developers, users, and platforms based on the AI agent’s degree of autonomy, the foreseeability of its conduct, and each party’s capacity for control.
Zhang et al. (2026) studied this question.