Station 02 · Window
Two orders that face each other
should never pay a pool.
A window is five seconds wide. Every order signed inside it is executed together, in one transaction, at one price per pair. Orders pointing opposite ways settle against each other first, and only what is left over is routed to the pools. Nothing an order says is public before it runs, and the output can land on an address with no history.
The contract that does this has been written and its rules were tested against a live chain, eleven of eleven, inside a single call. It is not deployed on Arc yet, so nothing has settled here and the counters below read nothing rather than reading history from somewhere else. The measurement the design rests on is further down, taken from this chain’s own traffic every few seconds while you read.
On the chain now
The contract, and every window it has settled.
A window is five seconds wide. Everything signed inside one is settled together, in one transaction, at one price per pair. Orders pointing opposite ways are matched against each other first and only the remainder is routed, so the two of them pay nothing to a pool and nothing to a bot watching the mempool. An order is a signed message, never a transaction, so it costs you no gas and it is not public until it runs.
Asking the engine.
Join the next one
Sign an order. The chain is touched once, later.
An order is a signed message, not a transaction. It names the pair, the exact amount, the floor under your output, the address the output goes to and the second it expires, and the contract enforces every one of those. The settler pays the gas, so signing costs you nothing, and an order it cannot cover at the window price is dropped rather than filled badly. Ether cannot enter a window, because the contract moves balances with an allowance and native ether has none to give, so the pay side is WETH.
Asking the engine which window is open.
The measurement, live
How much of this chain already trades against itself.
Reading the chain.
Two hours of the chain, 23 September 2026
27.2%
of volume faced the other way inside five seconds
$11.9M
that would never have reached a pool
33.5%
the same at ten seconds
$5,817
of pool fees not paid, on the part whose fee is known
Taken from 140,650 swaps the engine read between blocks 70,237,535 and 70,309,029, of which 117,730 carried a dollar side, $43.7m in all. Every figure here leaves out both legs of any single transaction, so a bot arbitraging two pools inside one transaction is never counted as two traders meeting. The raw figure, with those left in, is 28.2 percent at five seconds.
The mechanism
Four steps, and a contract that refuses the rest.
01
Sign, do not send
You sign an order: the pair, the amount, the least you will accept, where it should land, and when it expires. No transaction leaves your wallet, so there is nothing in flight for anyone to read, and nothing to cancel.
02
The window closes
Orders collect for a few seconds. What reaches the chain in the meantime is a hash, which says an order exists and says nothing about what it does.
03
Opposite orders cross
Inside the window, flow pointing both ways on the same pair settles against itself. That part pays no pool fee and moves no price, because it never reaches a pool. The remainder is routed the way the terminal already routes, across the venues that price it best.
04
One price, one receipt
Every fill in the window settles at the same price for its pair, and the contract rejects the batch if one fill is priced apart from the others or lands under the minimum you signed. Afterwards the receipt is on the chain: how many orders were in the transit, the clearing price, and how much crossed instead of being routed.
What it changes
Your wallet stops being a signal.
Nothing to copy
Wallet watchers and copy bots live on addresses with a record of being right. Output that lands on a fresh address has no record, so an entry stops being a signal other people can trade against a second after you take it.
Nothing to front
A limit order or a dip buy sitting in public is an invitation. An order that is only a hash until it executes cannot be positioned in front of, and one price per window means arriving first buys nothing.
Fees that are not paid
The part of your trade that meets someone going the other way pays no pool fee and takes no price impact. It is the one benefit here that arrives as a number rather than as a feeling, and it grows with the number of people using it.
What it does not do
Said here before anyone asks.
The purchase itself stays public. On a public chain without a shielded pool, the fact that an address bought a token is visible, and anyone claiming otherwise is either wrong or building a mixer. What a transit removes is the leak before execution and the trail your main wallet broadcasts afterwards.
This is not a mixer, and will not become one. Funds are never held, never pooled, and never withdrawn to somewhere unrelated. Every path through a transit is a trade, in one transaction, with a receipt.
In the first version we see the orders. They reach our relayer before they reach the chain. What protects you is the contract, which enforces one price and your minimum, and the receipt of every transit, which anyone can recompute. That is a reputation bond, not a proof, and the same words are on the proof page about everything else here.
A window with one order in it is not private. The set is only as large as the orders inside it, which is why the size of every transit is published rather than hidden.
The order of work
Smallest risk first, money last.
01
Hidden scheduled orders
The keeper already holds a swap until its window opens, with every parameter in plain sight. It takes a commitment instead, and reveals at execution. Same contract shape, no new settlement arithmetic.
02
Payouts to a fresh address
Stealth addresses, so the wallet people watch stops receiving what you earn, and the gas for that address comes out of the trade rather than from a wallet that links back to you.
03
The transit contract
Signed orders, one window, one price, netting first and routing second. It holds many people’s funds inside one transaction, which makes it more dangerous than the router, so it is tested against live pool state and rehearsed on the chain with small amounts before anyone is invited.