Machine Payments Protocol Ships Multi-Method Discovery (3 minute read)

Crypto paymentsinfrastructureapi Read original

The Machine Payments Protocol added multi-method discovery so payment services can advertise all supported payment options upfront instead of requiring clients to probe endpoints individually.

What: MPP updated its discovery specification to let payment services declare all their payment offers (across different methods like stablecoins, cards, Bitcoin, currencies, and billing types) in a single OpenAPI document, replacing the previous approach where clients had to make requests to discover each option dynamically.

Why it matters: This makes it easier for payment registries and AI agents to index and filter payment-enabled services without making exploratory requests, which is important as more services accept multiple payment methods and currencies on the same endpoint.

Takeaway: Developers using the mppx SDK will get multi-offer discovery documents automatically when configuring multiple payment methods.

Decoder

MPP (Machine Payments Protocol): A payment-method and currency-agnostic standard for machine-to-machine payments that supports stablecoins, cards, and Bitcoin
402 Challenge: HTTP status code that indicates payment is required, used to communicate payment requirements to clients
EVM: Ethereum Virtual Machine, the runtime environment for smart contracts on Ethereum and compatible blockchains
Intent: The type of payment operation, such as a one-time charge or a session-based subscription
Discovery document: OpenAPI metadata that describes what payment methods and currencies a service accepts

Original article

The Machine Payments Protocol (MPP), a payment-method and currency-agnostic standard with 10+ live payment methods spanning stablecoins on every EVM network, cards, and Bitcoin, shipped a major update to its discovery spec that allows servers to declare all payment offers ahead of time in a single discovery document rather than requiring clients to hit endpoints and parse 402 Challenges individually. The update enables services that accept multiple methods, currencies, and intent types on the same endpoint to advertise everything upfront, making it easier for registries and AI agents to find compatible payment options without dynamic probing. It's an infrastructure-level improvement for the machine-to-machine payments stack that sits alongside Coinbase's x402 and Amex's ACE kit.