Core Concepts/MPP Protocol

MPP Protocol

The Machine Payments Protocol (MPP) is an open standard for AI agent payments. MPPFinance implements MPP as the settlement and rules layer beneath every virtual card.

What is MPP?

MPP defines how AI agents request, authorize, and settle payments. It is built on top of Solana and Ethereum, using on-chain program logic to enforce rules without any centralized authority.

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MPPFinance is a compliant MPP implementation. Any MPP-compatible agent wallet can use MPPFinance without modification.

Payload spec

Every card issuance request contains a signed MPP payload:

mpp-payload.json

{
  "agentId": "agent-7x2k",
  "amount": 5000,
  "currency": "USD",
  "rules": {
    "merchant": "aws.com",
    "singleUse": true,
    "expiresIn": 300,
    "maxAmount": 5000
  },
  "network": "solana",
  "signature": "0x..."
}

On-chain rules fields

Field	Type	Description
agentId	string	Unique identifier for the agent
amount	number	Amount in cents (e.g. 5000 = $50.00)
currency	string	ISO 4217 currency code
merchant	string	Allowed merchant domain (optional)
singleUse	boolean	Card burns after first charge
expiresIn	number	TTL in seconds
signature	string	Agent wallet signature proving ownership