Flashbots’ BuilderNet to address Ethereum block builder centralization

BuilderNet is a new block building network designed to return more MEV and gas fees to users

article-image

Flashbots and Adobe Stock modified by Blockworks

share


This is a segment from the 0xResearch newsletter. To read full editions, subscribe.


Blockchains sell blocks. A complex market of actors are paid to assemble those blocks, but a part of that market — specifically block builders — is a duopoly between two players (Beaverbuild and Titan).

Source: Mevboost.pics

This duopoly is bad for various reasons, but chiefly in regard to maximal-extractable value (MEV).

MEV is believed to be monetary value that the end user creates, so returning it to them is ethically preferable. But when a few block builders dominate block building, that creates maximal value extraction that is suboptimal for the Ethereum end user.

To mitigate this, the Flashbots team announced today BuilderNet, a new block building network designed to return more MEV and gas fees to users.

Operating alongside Nethermind and the same Beaverbuild, BuilderNet looks to split up the presently “monolithic process” of block building.

This division of labor would allow existing stakeholders such as block builders, searchers and dapps to join a “multioperator network” and concurrently run the same block builder together. When blocks are assembled, rewards are then refunded back to stakeholders based on the amount of market value they’ve contributed to a block.

With BuilderNet, any application can permissionlessly and privately submit transaction order flow to a block builder and be paid for it on a pro rata basis.

Transactions stay private since the BuilderNet network will run in a “trusted execution environment” (TEE), an encrypted secure enclave that allows data to be processed without revealing order flow data.

Operators will also be able to permissionlessly deploy a block builder in BuilderNet.

According to official docs, this will enable an “even playing field where independent searchers can receive the same financial outcomes and privacy that integrated searcher-builders do today.”

BuilderNet in effect looks to thwart current industry practices in the block builder market that have sought to internalize MEV from end users. These include exclusive MEV revenue-sharing agreements between apps/wallets and block builders or other forms of vertical integration within the MEV supply chain between searchers and block builders.

Though BuilderNet will primarily benefit the Ethereum L1 today, it eventually plans to be available for decentralized sequencing on L2s through Rollup-Boost, the block building platform that will be used on Unichain.

Updated Dec. 11, 2024 at 3:51 pm ET: A previous version of this article incorrectly stated that Titan’s relayer accepted blocks exclusively from its own block builder, when in fact it accepts blocks permissionlessly from any block builder.


Get the news in your inbox. Explore Blockworks newsletters:

Tags

Decoding crypto and the markets. Daily, with Byron Gilliam.

Upcoming Events

Old Billingsgate

Mon - Wed, October 13 - 15, 2025

Blockworks’ Digital Asset Summit (DAS) will feature conversations between the builders, allocators, and legislators who will shape the trajectory of the digital asset ecosystem in the US and abroad.

recent research

Research Report Templates.jpg

Research

Figure, founded by former SoFi CEO Mike Cagney, has emerged as a leader in onchain RWAs, with ~$17.5B publicly tokenized. The platform’s ecosystem volume is growing ~40% YoY as it expands beyond HELOCs into student loans, DSCR loans, unsecured loans, bankruptcy claims, and more. Operationally, Figure cuts average loan production cost by ~93% and compresses median funding time from ~42 days to ~10, creating a durable speed-and-cost advantage.

article-image

The Ethereum co-founder suggested LINEA holders would be eligible for other airdrops in cryptic tweet

article-image

The layer-2’s biggest release yet brings benefits — but a post-upgrade outage caused a chain reorg

article-image

Crypto is shifting into risk-on mode — pump.fun dominates meme activity, while Lido leans on treasury maneuvers

article-image

If the president breaks the Fed, he’ll own the budget problems

article-image

Combining Franklin Templeton’s tokenization expertise with Binance’s trading infrastructure could speed crypto adoption, companies say

article-image

The firm’s upcoming filing comes as competition heats up over the USDH stablecoin