- the server challenges a paid request
- the client signs a payment credential
- the request is retried with an authorization header
- the server settles directly on-chain
Payment modes
Charge
Use charge payments for one-off requests.- one signed authorization per request
- built around ERC-3009 transfer authorization
- no channel state to maintain
Session
Use session payments when a client will make repeated requests.- open a channel once on-chain
- send cumulative off-chain vouchers after that
- settle when the server chooses
Why use MPP
- one protocol for one-off and repeated machine payments
- purpose-built for agentic HTTP flows
- lower repeated-request overhead with session channels
MPP vs x402
Abstract package and endpoints
Get started
Charge Payments
Integrate one-off paid requests.
Session Payments
Open channels and settle cumulative vouchers for repeated requests.