Sub-Dollar Machine Commerce: A Census-Scale Analysis of Real x402 On-Chain Payments

Abstract

Autonomous software agents are increasingly transacting over the HTTP 402 (x402) protocol, yet the empirical economics of machine-to-machine commerce remain largely uncharacterized. The prevailing industry narrative assumes a migration toward multi-dollar, compound transactions. To test this, we analyzed a census-scale dataset of 143.8 million x402 settlements—totaling $42.8M across Base, Solana, and Polygon (May–Dec 2025)—and found the exact opposite. Our analysis reveals three structural realities of the machine economy: The Sub-Dollar Reality: Machine commerce is overwhelmingly micropayment-driven. The volume-weighted average payment is just $0.27, and 28.5% of all transactions are sub-cent. Payments ≥$1 carry 72.5% of the total value but represent less than 8% of network traffic. Extreme Centralization: The top 1% of merchants capture 93.0% of all revenue. This bottleneck is even more pronounced at the settlement infrastructure layer, where a single facilitator controls ~62% of the total settled volume. Wild Price Dispersion & Network Dominance: Endpoint list prices are highly erratic (median $0.01, CV 12.91), decisively rejecting the hypothesis of a tight, efficient algorithmic clearing corridor. Furthermore, settlement is highly skewed toward Base (82.5% of volume), with Solana holding a persistent minority (17.4%). These findings dismantle the myth of complex machine commerce, reframing the x402 ecosystem as a high-volume, sub-dollar API economy where the true concentration risk lies in settlement infrastructure, rather than among merchants.