Orderflow Auctions Crypto

Orderflow auctions let users or wallets sell the right to execute their transactions to the highest bidder, often searchers or solvers, with part of the value returned to the user. They aim to give back MEV that would otherwise be captured by front-runners. MEV Blocker and similar services work this way. The design questions are who runs the auction, how bids are protected and how much value actually reaches users.

How one works, step by step

MEV Blocker, run with CoW Protocol, is a public example. You point your wallet at its RPC endpoint and send a swap as usual. The transaction goes to a private network of searchers and stays out of the public mempool, so sandwich bots never see it. Searchers can bid for the right to place a trade right after yours, a backrun that profits from the price move your swap causes. The winning bid is split: 90% goes back to you and 10% to the validator or builder. If nobody bids, your transaction just goes through privately.

Other designs

Flashbots' MEV-Share shares limited details about a pending transaction with searchers and returns part of their payment to the user. Intent based systems like CoW Swap and 1inch Fusion go further: you sign an order describing what you want, and solvers or market makers compete to fill it at the best price.

What to watch

A small set of searchers or builders can quietly coordinate their bids. Sharing more detail about a pending trade lets bidders pay more for it and also gives them more to work with. Some wallets sell their users' flow and keep most of the payment, so check where the refund goes.

Practical use

For swaps on Ethereum, using a protected RPC or an intent based exchange is a simple step that cuts sandwich risk. Set a sensible slippage limit anyway, and check that the refund address in the settings is yours.