MPP

The Machine Payment Protocol (MPP) is a standard for agent-to-agent financial transactions. HumanConnection implements MPP to allow AI agents to autonomously negotiate, quote, and settle payments for human-powered services — without human intervention on the payment side.

MPP support is planned for future releases. This page documents the intended integration.

Overview

While x402 handles simple pay-per-request API access, MPP enables richer payment workflows:

Quoted pricing: An agent requests a quote for a service, and HumanConnection responds with an itemized quote.
Escrow: Funds are held in escrow until the meeting is completed and a report is submitted.
Conditional payouts: Rewards to humans are released automatically based on meeting outcome.
Multi-party settlements: A single transaction can pay the human, the platform fee, and a referral agent.

How it works

Agent A                    HumanConnection (MPP)              Human
  |                              |                              |
  |-- mpp:quote --------------->|                              |
  |   {service: "sales_meeting",|                              |
  |    guests: [...],           |                              |
  |    budget: {amount: 500,    |                              |
  |      currency: "USD"}}      |                              |
  |                              |                              |
  |<-- mpp:quote_response ------|                              |
  |   {quote_id: "qt_...",      |                              |
  |    items: [                  |                              |
  |      {desc: "Meeting fee",  |                              |
  |       amount: 350},         |                              |
  |      {desc: "Platform fee", |                              |
  |       amount: 50}           |                              |
  |    ],                        |                              |
  |    escrow_address: "0x..."}  |                              |
  |                              |                              |
  |-- mpp:accept -------------->|                              |
  |   {quote_id, tx_hash}       |                              |
  |                              |                              |
  |<-- mpp:confirmed -----------|                              |
  |   {request_id: "req_..."}   |                              |
  |                              |                              |
  |                              |  [Meeting happens]           |
  |                              |                              |
  |                              |<-- report ------------------|
  |                              |                              |
  |<-- mpp:settlement ----------|                              |
  |   {outcome: "deal_closed",  |-- payout ---------------->  |
  |    human_payout: 350,        |   $350                       |
  |    platform_fee: 50}         |                              |

Escrow and trust

MPP uses on-chain escrow to protect both parties:

For the agent: Funds are only released after a verified meeting report is submitted.
For the human: Payment is guaranteed once the meeting is completed.
For the platform: The platform fee is deducted automatically at settlement.

Scenario	What happens
Meeting completed, deal closed	Human receives full quoted payout + commission
Meeting completed, follow-up needed	Human receives base payout
No-show by lead	Human receives 50% of payout, remainder refunded
No-show by human	Full refund to agent
No match found before deadline	Full refund to agent

MPP vs. x402

	x402	MPP
Payment model	Pay per API call	Pay per service (escrow)
Complexity	Simple	Rich (quotes, escrow, settlements)
Best for	Search queries, reads	Full service workflows
Refund handling	Automatic on API failure	Conditional on service outcome
Multi-party	No	Yes (human + platform + referral)

Supported networks

Currency	Network
USDC	Base
USDC	Ethereum
USDC	Arbitrum

Next steps

x402

Simple pay-per-request for API access.

OpenClaw

Build autonomous agents that use MPP for payments.