CoachProposer–builder separation is the division of block production between block builders, specialised parties that assemble the most valuable blocks from public transactions and private bundles and bid for the right to have them proposed, and proposers (validators) that choose the highest bid. An MEV relay is an intermediary that receives builders’ blocks, keeps their contents hidden from the proposer until it commits to propose, and forwards the best bid. A transaction bundle is an ordered list of transactions that a searcher submits to builders, to be included together and in that order, or not at all.
