Delivery-versus-payment, without the gap.
The settlement gap — the window between one party delivering and the other paying — is where counterparty risk lives. An atomic swap removes it: a bilateral exchange where every leg settles in a single transaction, or none does — many assets at once, with amounts kept confidential. Multi-party deals are then composed from these bilateral swaps. This note walks the mechanism end to end.
Where the risk actually lives
In bilateral settlement, someone moves first. Between delivery and payment sits a window in which default, fraud, or simple operational failure can leave one side short. That window is the settlement gap, and most of the machinery of modern markets exists to manage it.
The market’s answer has been intermediation — central counterparties, custodians, escrow agents — institutions that step into the gap and absorb the risk in exchange for cost, capital, and coordination. The gap never disappears. It gets insured, and someone pays the premium.
Atomicity as a settlement primitive
An atomic swap is a conditional exchange whose legs execute in a single transaction. The chain enforces all-or-nothing: if any leg reverts, the entire bundle reverts. A half-settled state is not monitored-for and unwound after the fact — it is unrepresentable by construction.
This is delivery-versus-payment, and payment-versus-payment, without a discretionary settlement agent in the middle. The contract holds the offered assets in escrow under code — it takes no beneficial interest and exercises no discretion, and it refuses to settle one leg unless every leg settles.
The anatomy of a swap
A YieldFabric swap is a set of legs the initiator defines up front. Each leg names an asset and a direction; the contract bundles them and will only move them together. Nothing in the bundle takes effect until all of it can.
What the initiator puts in — tokenised cash, an obligation, or a position to be exchanged.
What the other side delivers in return — the matching half of delivery-versus-payment.
Optional assets pledged into escrow as part of the exchange — the basis for repo and secured swaps.
All legs grouped into one transaction that settles together or reverts together — never partially.
A per-leg validity proof — sufficient balance, valid ownership, valid transition — that gates execution without revealing amounts.
How a swap settles
The proofs bracket the exchange: each leg is proven before it is bound, the swap itself settles in one atomic transaction, and confidential value is delivered against a final proof on accept.
- 01Propose
The initiator defines the legs — what is offered, what is requested, any collateral — and creates the swap. The offered obligations are escrowed into the contract.
- 02Prove
Each confidential payment already carries a verified zero-knowledge send-proof — sufficient balance, valid ownership — checked in the vault when the payment was created, without revealing the amount.
- 03SettleAtomic
The counterparty calls complete. The contract re-validates every leg by reference — active, correctly bound, right sender and recipient — and moves all of them in one transaction. If any check fails, the whole call reverts; no half-settled state can exist.
- 04Accept
The payee accepts each payment, running its receive-proof. Confidential value is delivered, balances stay private, and each side holds a verifiable record an auditor can check without seeing the rest.
Two parties, many assets
A swap is always bilateral: an initiator and a counterparty. What gives it range is that it is multi-asset — each side can move several assets in the same atomic exchange. Cash against an obligation and its collateral, for instance, all settling together or not at all.
Structured finance also separates custody, control, and economic exposure across more than two parties. That is not one giant swap — it is composition: a deal is assembled from bilateral swaps, each atomic in itself, plus composed bundles where the operations a single party mints settle all-or-nothing together. The result is a multi-party structure built from atomic bilateral pieces — without any swap pretending to be multi-party.
Confidential by construction
On a public ledger, naïve settlement leaks amounts and counterparties to every observer — a non-starter for institutional flow.
YieldFabric’s swaps carry zero-knowledge proofs: the proof demonstrates the rules hold without revealing the figures. The public proof outputs are salted per payment, so an observer cannot brute-force an amount from a bounded set of possibilities. The proof gatekeeps execution; authorised auditors receive the artefacts they need without full public disclosure.
Why it changes the economics
Remove the settlement gap and you remove the reason for the apparatus built around it: the margin posted against settlement risk, the buffers, the reconciliation, the intermediary that prices the exposure.
Bilateral settlement gains the safety that previously required a central counterparty — without the central counterparty. Smaller and more bespoke trades become viable, because the per-trade cost of being safe collapses toward the cost of a single transaction.
In Project Acacia, the structure moved tokenised AUD, loan tokens, and pledged collateral across five independent parties — an issuer, two trustees, an investor, and a borrower. Each exchange was a confidential atomic swap between two of them; origination, the capital call, and repurchase settled in wholesale central-bank digital currency, composed so that no leg could settle unless every leg did. References are descriptive; no endorsement is implied.
From research to product.
Project Acacia was the pilot. YieldFabric is the platform — the same rails run private-credit facilities, securitisations, and bilateral deals today.