This document outlines the design for a marketplace for block construction (often referred to as block proposer / block builder separation or PBS) compatible with the upcoming Ethereum merge fork. This trust based solution closely resembles the current Flashbots auction design with modifications to enable solo staker participation without introducing changes to Ethereum consensus. This solution aims to bridge the gap to a permissionless PBS design which should be strongly considered for the cleanup fork in order to improve decentralization.
Ethereum will soon transition from a Proof of Work (PoW) to a Proof of Stake (PoS) consensus protocol. This transition has been worked on for years and is happening in multiple steps. The first step in December 2020 consisted in launching the beacon chain. It is now live, and, at the time of writing, has more than 160k validators or an equivalent of ~5m ETH staked on it.