Distributed block building: splitting block assembly among many
Strawmap Beyond that (Long term) · distributed block building
Today a small number of external builders construct whole blocks and hand them to validators. Distributed block building is a long-term research item that lets many participants share the work of assembling a block, so that no single party controls its contents.
Why it is needed
In Ethereum, validators mostly do not build blocks themselves and instead hand that job to external builders. A builder selects transactions, orders them, and sends the finished block to the proposer along with a fee. The proposer picks the block that pays the most. Under this structure, a small number of builders decide which transactions go into a block and in what order they are processed. If a few builders filter out certain transactions, it effectively becomes censorship. The more the builder business concentrates in a few companies, the greater the risk that the network depends on the judgment of a single party. Inclusion lists (FOCIL) prevent censorship by forcing omitted transactions to be included, but they leave the fact that only a few parties assemble blocks unchanged. Distributed block building aims to address this root cause by having many participants share the assembly of the block itself. The goal is that no single party can decide an entire block alone. In the Strawmap it sits in the long-term column of the consensus layer, and it is classified as client, specification, and networking work rather than a protocol rule change. How to split and merge the work is still at the research stage, so the design may change or the item may be dropped, and it is not assigned to any specific fork.
How it works
- Block production today Validators mostly do not assemble blocks themselves. They pick the block with the highest fee from among those that external builders have completed and sent. Builders decide what goes into a block.
- Splitting the assembly Instead of one builder making an entire block, distributed block building aims for many participants to each submit a bundle of transactions and have those combined into a block.
- No single party controls it No single participant can drop a particular transaction or set the order alone, which reduces censorship and concentration. The specific rules for combining the parts are still under research.