Protocol

MPP Compatibility

Where HoodLayer stands relative to the Machine Payments Protocol from Stripe and Tempo.

MPP (Machine Payments Protocol) is an open standard, tracked at the IETF, for machine-to-machine payments over HTTP. Stripe and Tempo published it in March 2026. It takes the x402-style request-pay-retry pattern and extends it with Stripe’s billing infrastructure plus Tempo’s L1 settlement layer.

HoodLayer is built so that MPP-speaking clients can use it, with their payments routed through Robinhood Chain instead of Stripe/Tempo infrastructure.

How MPP relates to x402

At their core, MPP and x402 work the same way: a 402 Payment Required response says the resource costs money, the client settles up, then retries with a proof attached. What MPP adds is formalization as an IETF draft, including:

  • A standard schema for payment negotiation
  • Defined settlement profiles (Stripe, Tempo, possibly more later)
  • Structured error codes plus retry semantics

Any MPP-compliant agent should be able to parse HoodLayer’s HTTP payment response. The split happens at the settlement layer: MPP routes to Stripe/Tempo, while HoodLayer routes to Robinhood Chain.

What this means for agent developers

If your agent already speaks MPP (say, through a framework that implements the MPP client spec), it can talk to HoodLayer-powered endpoints with no code changes. It reads the 402 response, picks a payment scheme it knows, pays, and retries. The settlement layer stays opaque from the agent’s point of view.

The one thing an MPP agent would actually notice is the network field in the payment object:

{
  "network": "robinhood-mainnet",
  "token": "0xecdda8f70c0880d915f746c861ace5dd58721a74"
}

A Stripe-backed MPP endpoint would carry Stripe’s settlement details there instead. As long as the agent holds a Robinhood Chain wallet and can reach the HoodLayer Facilitator, it can pay.

What this means for service providers

Already taking MPP payments through Stripe? You can add HoodLayer as a second settlement option without touching your API structure. The payment gate slots a Robinhood Chain native option into your 402 response next to the existing Stripe one, and agents choose whichever matches their wallet.

HoodLayer’s IETF roadmap

The plan is to submit a Robinhood Chain native MPP settlement profile to the IETF draft, sitting alongside the Stripe/Tempo submission. That work is slated for Phase 3 (Q1 2027), once the MPP specification is stable enough to take an alternative settlement profile.

Current status

For now, while HoodLayer is in beta, MPP compatibility is tracked informally. The SDK produces and consumes responses that line up structurally with MPP, though formal certification against the IETF draft won’t happen until after beta. Building an agent framework and want to check HoodLayer’s MPP compatibility in your stack? Get in touch through the beta program.