Fast Protocol

Fast Protocol is a transaction execution layer on Ethereum mainnet that runs an order flow auction: swaps routed through FAST RPC enter mev-commit's encrypted mempool, where builders post slashable stake and issue a cryptographic preconfirmation for a specific block position, returning a result in roughly 200 milliseconds while settlement still occurs in the next block. It targets the visibility, twelve-second finality and value leakage of the public mempool, using builder competition to return at least 90% of generated MEV as a better execution price, with Permit2 removing the separate approval transaction. The product is a drop-in RPC endpoint plus a swap front end: traders get sub-second confirmation, builders and validators get order flow and preconfirmation fees.

Unlike batch-auction aggregators it leaves the settlement layer untouched and only adds a commitment layer before block production. FAST RPC covers Ethereum mainnet alone, so swaps on other chains still use conventional routes, and the force of a preconfirmation rests on builder stake and actual slashing.