AI payment agent Definition.

Autonomous software agent, usually driven by an AI model, that searches, compares, and initiates payments on a user’s behalf. Not to be confused with a “payment agent” under PSD2, which is a registered agent acting for a PSP. The rise of AI agents spawned dedicated protocols in 2025 (Google’s AP2, OpenAI and Stripe’s ACP, Coinbase’s x402) and raised the question of a verifiable mandate linking the agent to an auditable human intent. The core security challenge is to authenticate the agent and limit its authority, hence the concept of Know Your Agent.