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How MPPI works

Inference is measured in tokens. Payment settles in USDC. Follow the work from a funded session to confirmed collection.

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Exchange inference tokens. Settle in USDC.

Set your prices, serve inference and report the tokens used. MPPI checks payment authorization before work starts and calculates what you can collect in USDC.

Inference tokens measure a model's input and generated output. MPPI prices that usage in USDC. Each request keeps the prices it accepted, even if the agent provider later changes its catalogue.

From inference to settlement

The inference exchangeMPPI / Arc

01Discover

Inference
Choose a provider and model.
Payment
Read identity and accepted prices. Request unpaid setup on Control.
On Arc
Verify the provider and trusted deployment. No inference deposit yet.
Agent and provider SDKs exchange inference and payment messages. Arc confirms USDC funding, collection and refunds.
StageInference and paymentBlockchain stage
DiscoverChoose a provider and model. Read identity and accepted prices. Request unpaid setup on Control.Verify the provider and trusted deployment. No inference deposit yet.
FundPrepare the session before paid work. Choose a USDC deposit. Authenticate the Control attachment after funding confirms.The funding wallet opens escrow. Confirmed evidence establishes the session and signer.
AdmitPrepare prefill counts and an output bound. The SDK checks signed prices and shared payment coverage before dispatch.Check fresh session, pause and deadline evidence. Reusing a ready session needs no new opening.
GenerateExecute covered work and return output. Report cumulative tokens and renew signed authorization as needed. Further deposit is explicit.Meters and vouchers stay off-chain. Eligible capture can occur while the session is open.
AccountSupply definitive counts and outcome. Account once. Release unused reservation. Send matching Terminal and Receipt records.A receipt reports the confirmed settlement observed so far; it need not trigger a transaction.
CollectThe session can continue serving requests. Capture accumulated reported usage within the signed ceiling, deposit and deadline.Confirmed capture pays the fixed recipient in USDC. Submission alone is not payment.
CloseStop new grants and finish accounting. Cooperative close accounts for final work. Other wallet exits have separate eligibility rules.Confirmed close captures any eligible remainder and refunds unused escrow to the funding wallet.

The map connects stages of inference to payment events. Collection can happen while a session stays open; each token does not need its own blockchain transaction. The map does not represent measured timings.

Before work: the provider measures input requirements and an output budget. MPPI checks deposited funds and signed payment authorization, including funds reserved for other requests in the same session. Insufficient funds stop admission; a later top-up does not restart that request.

During work: the provider reports cumulative usage at least every 1,000 output tokens, earlier when needed, and at completion. The SDK renews authorization as work progresses. If coverage runs out, the provider must stop within the covered budget. Unresolved work keeps its reservation.

Your provider counts the tokens. The contract limits how much it can collect; it cannot verify those counts.

Build your integration

Why Arc

How the SDKs connect

Coming from an HTTP API

How MPPI works | Agent providers | MPPI Docs