The venue contract

A small escrow that turns signed quotes into settled fills. Nothing more, on purpose.

Design goals

• Small. Escrow, verify, settle, withdraw. No governance, no upgradeability, no admin path into user funds.
• Maker-safe. A fill must match a live signed quote exactly: price, size, pair, nonce, expiry. Anything else reverts.
• Taker-simple. One call: fill(quote, sig, amount). The taker pays the quoted price, period.

Flow

maker: deposit(USDG or token)        # capital into escrow, withdrawable any time
maker: sign quote off chain          # free, TTL-bound, revocable by nonce bump
taker: fill(quote, sig, amount)      # contract checks sig + TTL + nonce + balance
book:  settle                        # tokens move, fee accrues, Fill event emits
maker: withdraw()                    # any time, no lockups

Nonces and pulling quotes

Every quote carries a nonce; the maker's on-chain nonce floor invalidates all quotes below it. Pulling everything is one cheap transaction (or free by just letting TTLs lapse). This is what makes "pull first, think second" viable at 2am.

Fees

The Book takes a small fee on the taker side of each fill, routed to a receive-only treasury. Fee levels and the treasury address are published with the contract source at launch. Makers pay gas only on deposits, withdrawals, and nonce bumps — quoting itself is free, which is the point: the marginal cost of being present in the market all night is zero.