Get Started With MEV-Boost & Blocknative Dreamboat

Blocknative Ethereum Web3

The Ethereum Merge was about more than moving the network to Proof-of-Stake. The upgrade also introduced the concept of Proposer/Builder Separation (PBS) to the network via an open-source protocol “sidecar” called MEV-Boost.  

While in-protocol PBS will eventually replace MEV-Boost, for the time being after The Merge it will fulfill the important role of connecting validators to Ethereum block builders. These builders specialize in the sophisticated task of sourcing, analyzing, and structuring Ethereum transactions for permanent inclusion on-chain. Validators can then use MEV-Boost to select these blocks and propose them to the network for attestation and block inclusion.

The MEV research and development organization Flashbots spearheaded the design of MEV-Boost and continues to maintain it as an open-source project. The project’s GitHub page describes it as such:

“MEV-Boost is a sidecar for the Consensus Client, a separate piece of open source software, which queries and outsources block-building to a network of builders. Block builders prepare full blocks, optimizing for MEV extraction and fair distribution of rewards. They then submit their blocks to relays.”

As outlined in the graphic below, MEV-Boost connects to relays that aggregate blocks from dedicated block builders and select blocks based on the fees that are contained within. Blocknative offers an open source MEV-Boost relay known as Dreamboat.


Image from MEV-Boost GitHub

Validators that wish to capture the rewards made available via MEV will want to use MEV-Boost. If a validator chooses not to use the sidecar, they will instead receive non-optimized blocks directly from their execution client.

PBS, MEV-Boost, and the new role of block builders represent uncharted territory for the Ethereum network. It will take time to see how the new economics of block building evolve. However, the general hope of the community is that these upgrades will allow for MEV capture on Proof-of-Stake to happen in a more decentralized, transparent, and equitable manner.

To begin using MEV-Boost, we recommend the instructions below from our MEV-Boost relay docs page:


MEV-Boost can run in any machine, as long as it is reachable by the beacon client. The default port is 18550. The most common setup is to install it in the same machine as the beacon client.


From source

Install MEV-Boost with go install:

go install
mev-boost -help

Or clone the repository and build it:

git clone
cd mev-boost
make build
./mev-boost -help

From Docker image

An MEV-Boost Docker image is maintained at

# Get the default mev-boost image
docker pull flashbots/mev-boost:latest

# Get the portable mev-boost image
docker pull flashbots/mev-boost:latest-portable

# Run it
docker run flashbots/mev-boost -help


If MEV-Boost crashes with SIGILL: illegal instruction" then you need to use a portable build:

You can either use a portable Docker image, or install/build the portable build like this:

# using `go install`
CGO_CFLAGS="-O -D__BLST_PORTABLE__" go install

# build from source
make build-portable


A single MEV-Boost instance can be used by multiple beacon nodes. Note that aside from running MEV-Boost, you will need to configure your beacon node to connect to MEV-Boost and your validator to allow it to register with the relay. This configuration varies and a guide for each consensus client can be found on the MEV-Boost website.

Relay types

Blocknative provides one MEV relay that validators can connect to. The relay is:

  • publicly available
  • publicly listed & maintained
  • open source
  • transparent about address filtering

Relay Endpoints

Blocknative’s relay is currently in alpha but has been heavily stress-tested. It supports all Proposer and Builder APIs outlined in the Relay spec seen here. Currently, our relay has only one trusted builder, but we plan to expand to multiple external builders in the near future.

Validators with MEV-Boost can connect to the Blocknative MEV relay in order to receive full blocks proposed by Blocknative. Validators can use the endpoints below:

Mainnet Validator

Goerli Validator

Ropsten Validator

Monitoring APIs

Please visit our MEV relay docs page for the most up-to-date monitoring APIs.


If you have any questions about the Validator relay, join our discord. If you'd like to learn more about running your own validator, we recommend our Lighthouse/Geth setup guide.

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