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A liquidity ad is the on-chain offer that makes peer-to-peer bridging possible. When a Maker posts an ad, they commit liquidity in a specific token on one chain against deposits of a specific token on another. Bridgers pick the ad that matches their transfer.

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What a liquidity ad contains

  • The route: which token a Bridger deposits, and which token (on which chain) the Maker provides. Tokens pair 1:1 by value, less the fee; amounts are aligned across token decimals automatically (decimal scaling).
  • Pool amount: the liquidity the Maker has escrowed
  • Min / max per trade: optional limits
  • Settlement signer: the wallet whose settlement key co-signs the Maker’s side of every trade. Usually the Maker’s own wallet. If it’s another wallet, that wallet has to approve the Maker first.
  • Ad ID: the identifier orders and proofs reference
These live on-chain in the AdManager contract; the app’s routes are built from them. The ad’s maker can be a wallet or an agent account. Only an ad held by an agent account can be served by an agent.

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Ad lifecycle

1

Create + fund

The Maker submits createAd and escrows the pool. Only funded ads serve orders.
2

Reserved by an order

A Bridger creates an order against the ad, and the matching slice of the pool is reserved before any money moves. Reservations from orders that are never funded are released after ~30 minutes, so abandoned checkouts can’t strand liquidity.
3

Locked for the order

Once the Bridger’s deposit confirms, the Maker locks the reserved liquidity on-chain (lockForOrder). This is the Maker’s deposit into the trade. Both deposits are recorded in their chain’s Merkle Mountain Range.
4

Co-signed

Both parties sign the settlement with their settlement keys. The trade can’t settle without both signatures.
5

Settled, or ended

The payouts are proven and submitted on both chains. The locked amount leaves the ad, less the LP fee, which stays in the pool. If the trade doesn’t settle by its deadline, the lock returns to the ad through the cancel path.
6

Closed

The Maker can close the ad and reclaim the remaining pool once its trades have ended.

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Available vs pool

The amount a new order can take is the on-chain pool minus the holds of open trades (reservations and locks).
Don’t close an ad while trades are in progress: locked amounts stay held until their trades end.

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Pausing

When the contracts are paused, nothing new can start: no new ads, funding, locks or orders. Everything already under way can still finish, settle, cancel or be refunded, and no deadline is stretched.

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What prevents double-spends

Each payout consumes a nullifier, a one-time value bound to the trade and the side it pays. Once it’s recorded on-chain, any replay is rejected, independently on each chain. Together with the co-signed roots and the co-signed nullifiers, a deposit settles exactly once, in exactly one direction, with both parties’ consent.