Combos

What a combo is#

A combo is one ticket that wins only if every selected outcome wins. You pick between two and eight open binary markets, one outcome on each, and an amount. A maker quotes the amount they will put up against yours; if you accept, both amounts go into escrow and the ticket settles once every leg has resolved.

There is no partial payout and no early loss settlement: a ticket with one lost leg still waits for the rest to resolve, and no leg can be cashed out early. Tickets are not transferable. Version 1 charges no protocol fee.

How a quote happens#

1. Register the combination. The combination of legs is written to the combo registry the first time anyone uses it. That is an on-chain transaction and needs gas; registration is permissionless and idempotent.
2. Request quotes. Your request — your wallet, your legs and your amount — is published to makers through a relay. Requests expire after two minutes. The request moves no USDG.
3. A maker signs an offer. The offer is a typed-data signature naming you as the only taker, the exact amount you asked for, the maker's amount, a nonce and an expiry no more than two minutes ahead. The relay re-verifies each offer against the chain before showing it, because a maker can cancel or spend their funds after quoting.
4. Accept and fund. Accepting first approves USDG for the escrow if needed, re-fetches the offer to make sure it is still the one you saw, simulates the fill, and then sends it. The fill pulls both contributions in one transaction.

The interface shows what you win as your amount plus the maker's, and says that the offer is rechecked before submission.

Eligibility#

A leg must be an open pool market with exactly two outcomes whose opening time has passed and whose cut-off has not. Eligibility is checked against the factory's own cut-off times, not the relay's clock, and again on chain at fill time.

Settlement#

Anyone may settle a ticket once every leg has resolved. If all your outcomes won, you are credited the whole pot; if any lost, the maker is credited the whole pot. If any leg was voided, or resolved with a payout shape the combo cannot interpret, both sides are credited back exactly what they contributed. Credits are withdrawn by the recipient, so neither side can block the other's payout.

Limits stated in the relay#

You can have up to five open quote requests at a time. A request can receive up to 20 maker offers, and amounts are limited to 100,000 USDG. If the request service is full, try again later.