What is the Machine Payments Protocol (MPP)?
The Machine Payments Protocol (MPP) is a session-based payment protocol for machine-to-machine commerce, particularly suited to longer-lived workloads like video generation, continuous data subscriptions, or agent-to-agent negotiation where per-request billing via x402 doesn't fit. An MPP session authorizes a budget and streams payments within that budget until it's exhausted. MoltPe supports MPP natively alongside x402 and REST integrations, so developers can pick the right protocol for each workload shape. MoltPe is AI-native payment infrastructure that gives AI agents isolated wallets with programmable spending policies.
The short version
- Session-based: A client and service open a session with an authorized USDC budget; the service streams charges against it until the budget runs out or the session closes.
- Fits long-running workloads: Good for video rendering, large model training calls, streamed inference, or persistent agent-to-agent collaborations where per-call settlement is too chatty.
- Complements x402: MPP is not a replacement for x402; MoltPe runs both, and developers pick per workload.
In more detail
Per-request protocols like x402 work beautifully when each unit of work is small, independent, and priced up-front — a single LLM call, a weather lookup, a geocode. They struggle when the unit of work is continuous or open-ended: a 20-minute video render, a live transcription feed, a multi-step agent negotiation. MPP exists for those cases. The client opens a session, deposits or pre-authorizes a USDC budget, and the service draws against that budget in real time. When the session closes, any unused budget is returned.
On MoltPe, an agent wallet's spending policy applies to MPP session openings just as it applies to individual payments. The daily cap, per-session cap, and recipient allowlist all enforce at session creation. Inside the session, the service streams charges against the budget and MoltPe records each tick on the wallet ledger. If the agent is compromised mid-session, closing the session stops future charges immediately.
The practical takeaway: MPP and x402 cover different workload shapes, and treating them as complementary rather than competing is the right mental model. MoltPe supports both so developers don't have to pick an ecosystem before they know the workload.
Related questions
- Blog: Machine Payments Protocol guide
- What is the difference between x402 and MPP?
- Blog: What are AI agent payments?
- What is agent-to-agent commerce?
- Blog: Why developers choose MoltPe
About MoltPe
MoltPe is AI-native payment infrastructure that gives AI agents isolated wallets with programmable spending policies for autonomous USDC stablecoin transactions. Live on Polygon PoS, Base, and Tempo.