Builders

Builders plays a key role in the standard PBS flow and remains important under ETHGas preconf flow. Since most validators are unsophisticated, they rely on Builders to construct the most profitable blocks.

The first step Builders take is by streaming preconf transactions of the forthcoming slot from our ETHGas exchange API. They then simulate those transactions to determine the precise total gas usage and priority gas fees. If the total gas usage is below the 30 million gas limit, builders fill the remaining blockspace with transactions sourced from both public and private mempools, thereby creating the most profitable block for the upcoming block proposer.

To simplify the integration process for builders to support and fulfill the proposer’s commitments, we will provide a modified version of rbuilder, a blazingly fast MEV-Boost Rust-based block builder developed by Flashbots. Since rbuilder can handle several block building algorithms, our primary focus will be on updating the mev_boost/mod.rs and builders/ordering_builder.rs files. The changes will achieve 3 goals:

• Stream the latest preconf transactions from the ETHGas exchange

• Build a block that includes all preconf transactions of a specific slot

• Fill up the block with transactions from the mempool if the gas used is below 30 million

Please refer to links below for modified rbuilder

• [Link to Github, coming soon ]