The core advantage of the x402 ecosystem lies in being designed for machines: no merchant account required, no KYC needed, and payments can be processed with just a few lines of code on any server. Settlements are based on stablecoins, with per-transaction costs as low as fractions of a cent, natively adapted to Agent's high-frequency microtransaction billing model. ACP and AP2 essentially integrate AI into existing card networks and merchant systems: they serve the purpose of 'AI helping people buy things,' whereas x402 serves 'direct transactions between machines.'