{ Protocol
Settlement
One Arc transaction. USDC gas. A fill, not a mempool order.
Settlement is one Arc transaction. USDC in, asset out, surplus split, burn. Gas is USDC, so the fill quote and the fee quote are the same unit.
| Finality | Under one second. Deterministic enough for a block auction. |
|---|---|
| Gas asset | USDC. No separate gas token in the quote. |
| Receipt | A fill event. Not a public marketable order sitting in a mempool. |
| Failure | Revert grief is a slash, not a free option on the signer. |
Atomic fill
F = transfer(ain) ∘ transfer(aout) ∘ split(S) ∘ burn(πb)
Either the whole composition lands or nothing does. The signer’s funds never sit unlocked while a solver shops for inventory.
What the ledger shows
The public record is the fill: amounts, rate, solver, surplus. The want itself is not a searchable pending swap. MEV that hunts mempool orders has nothing to hunt.