Agent commerce protocols proliferate beyond crypto-native stacks

Stripe, Visa, and other incumbent payments and model vendors published overlapping agent-commerce interfaces through 2025–2026, including Stripe's Agentic Commerce Protocol with MPP and x402 support and Visa's Intelligent Commerce, according to a zFinia retrospective published 7 September 2026. zFinia said the overlapping vocabulary creates a classification problem for buyers and a coverage obligation for itself, and that its editorial work is mapping substitutes and complements rather than treating the machine economy as a single protocol.