Ethereum Brings Multi-Party Block Construction to Mainnet
Ethereum has rolled out its multi-party block construction (MPBC) feature on mainnet, allowing multiple builders to contribute transactions to a single block.
The initial version of MPBC uses an append-only model, where one builder creates the initial block and additional builders can add eligible transactions before the block reaches the proposer.
Under Ethereum's existing proposer-builder separation (PBS) architecture, builders assemble blocks and compete to have their blocks selected by validators acting as proposers. However, MPBC changes this process by allowing additional builders to contribute content without having to win the entire block auction.
The system is currently being used by several infrastructure providers, including Aestus, Titan, and Ultra Sound, which coordinate contributions from different builders before sending the resulting block through the existing transaction pipeline.