Machine Payments Protocol (MPP)

MPP is an open payment protocol for machines, enabling AI agents to pay for resources over HTTP without API keys or billing accounts. Zeny supports both MPP intents: charge and session.

MPP vs x402

Aspectx402MPP
ModelPer-request paymentCharge + session streaming
HeadersPayment-Required / Payment-SignatureWWW-Authenticate / Authorization
Best forOne-off API callsStreaming, high-frequency use

Intents