MEV Relay Instructions for Ethereum Validators

Connect to Blocknative’s MEV-boost relay and monitoring APIs. Our relay is under active development in collaboration with the builder/relay community and follows Semantic Versioning rules.

What is MEV-boost

MEV-boost is open source middleware run by validators to access a competitive block-building market. MEV-Boost was built by Flashbots as an implementation of proposer-builder separation (PBS) for proof-of-stake (PoS) Ethereum.
With MEV-Boost, validators can access blocks from a marketplace of builders. Builders produce blocks containing transaction order flow and a fee for the block proposing validator. Separating the role of proposers from block builders promotes greater competition, decentralization, and censorship-resistance for Ethereum.
Don’t have MEV-Boost setup? Click here for directions on how to set it up.

Blocknative Relay

Blocknative provides one MEV relay, the Blocknative Relay, that validators can connect to. The relay is:
  • publicly available
  • publicly listed & maintained
  • transparent about address filtering
Blocknative is based on the Dreamboat code base. It is fully open source and can be accessed on Github here.

Relay Endpoints

Blocknative’s relay 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 must connect to the Blocknative relay to receive full blocks proposed by Blocknative. Use the endpoint below to do this:

Mainnet Validator Endpoint

https://0x9000009807ed12c1f08bf4e81c6da3ba8e3fc3d953898ce0102433094e5f22f21102ec[email protected]
#Run MEV-Boost pointed at Blocknative's mainnet relay:
./mev-boost -mainnet -relay-check -relay https://0x9000009807ed12c1f08bf4e81c6da3ba8e3fc3d953898ce0102433094e5f22f21102ec[email protected]

Goerli Validator Endpoint

https://0x8f7b17a74569b7a57e9bdafd2e159380759f5dc3ccbd4bf600414147e8c4e1dc6ebad[email protected]
#Run MEV-Boost pointed at Blocknative’s Goerli relay:
./mev-boost -goerli -relay-check -relay https://0x8f7b17a74569b7a57e9bdafd2e159380759f5dc3ccbd4bf600414147e8c4e1dc6ebad[email protected]

Monitoring APIs

To increase visibility and transparency Blocknative’s relay supports the following monitoring APIs. For a full list of API specs please visit Flashbot’s Relay API Spec.


BidTrace payloads delivered to proposers.
How to query:
curl -X GET


BidTrace payloads for blocks submitted by builders.
How to query:
curl -X GET


Return the latest validator registration for a given pubkey.
Example query:

Setting up MEV-boost

How does MEV-Boost work?

PoS node operators must run three pieces of software: a validator client, a consensus client, and an execution client. MEV-boost is a sidecar for the beacon node - 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.
Relays aggregate blocks from builders in order to select the block with the highest fees. One instance of MEV-boost can be configured by a validator to connect to multiple relays. The consensus layer client of a validator proposes the most profitable block received from MEV-boost to the Ethereum network for attestation and block inclusion.

What are MEV-Boost Relays?

MEV-Boost relays are the infrastructure that is used to directly connect validators and block builders. Relay connections are configured within MEV-Boost and validators can connect to as many relays as they prefer. By doing so, they generally improve their overall profitability.

Setup MEV-boost for your validator

Node operators need to set up MEV-Boost to connect to the Blocknative MEV relay. Mev-boost is available on Github or Docker Hub. Please refer to MEV-boost usage instructions and a full set of setup instructions in the testing guide on GitHub, outlined below. Our relay is also compatible with other MEV-boost-compliant validators such as vouch.

Download and Install

The most common setup is to install MEV-Boost on the same machine as the beacon client. Multiple beacon-clients can use a single MEV-Boost instance. The default port is 18550.

Binary Release

Download the latest MEV-boost binary for your architecture here.

From Docker image

Flashbots maintains mev-boost Docker images at
  • Pull & run the latest image:
# Get the default mev-boost image
docker pull flashbots/mev-boost:latest
# Or, get the portable mev-boost image
docker pull flashbots/mev-boost:latest-portable
# Run it
docker run flashbots/mev-boost -help
Refer to the documentation for usage instructions.

Configure and Run

A single MEV-Boost instance can be used by multiple beacon nodes and validators. Aside from running MEV-Boost on your local network, you must configure:
  • individual beacon nodes to connect to MEV-Boost. Beacon Node configuration varies by Consensus client. Guides for each client can be found on the MEV-boost website.
  • individual validators to configure a preferred relay selection. Note: validators should take precautions to only connect to trusted relays. Read more about the role of relays here.
The tutorial above focuses on connecting to Blocknative’s relays. You can find additional relays on the lists maintained by


If you have any questions about the Validator relay, join our discord.