Prysm and MEV Boost Relay

This documents the necessary steps to run Prysm beacon client and validator client for MEV extraction. It 's important to keep in mind that these are prototypes so expect breakages and bugs. The instructions will likely change later and we 'll update them along the way. With that said, we are months away from the merge, and now is a crucial time to begin testing MEV as an end-to-end product from validator to beacon node to mev-boost to relayer and to a builder.

#Optional readings on the why what and how lightclient - Extracting MEV After the Merge Bulder API spec

#Prysm images

To build from source. Please use latest develop branch To use dockers. Here are the docker images:

Beacon client: Validator client:

Instructions on how to run testnets

Installation guide Fee recipient guide There are two ways to set up your fee recipient. One way is --suggested-fee-recipient. This means every validator will use that fee recipient. Another way is through a config file. This enables customization. Example:

	"proposer_config": {
		"0xa057816155ad77931185101128655c0191bd0214c201ca48ed887f6c4c6adf334070efcd75140eada5ac83a92506dd7a": {
			"fee_recipient": "0x50155530FCE8a85ec7055A5F8b2bE214B3DaeFd3",
			"validator_registration": {
				"enabled": true,
				"gas_limit": 30000000
		"default_config": {
			"fee_recipient": "0x6e35733c5af9B61374A128e6F85f553aF09ff89A",
			"validator_registration": {
				"enabled": true,
				"gas_limit": 30000000

#⚠️ Additional flags

For your testnet beacon client, you will want to point them to the existing relays. Flashbots has kindly provided us with these relays for testing. Kiln: Ropsten: Sepolia:

On your testnet beacon client. Add the --http-mev-relay flag

Example for Sepolia: --http-mev-relay= --sepolia

On your testnet validator . Add the --enable-builder flag

Example for Sepolia: --suggested-fee-recipient=0xD9A5179F091d85051d3C982785Efd1455CEc8699 --sepolia --enable-builder

#Running your own mev-boost

The above section utilizes direct connection to relay. This is not intended for production. In production, beacon node should connect the mev-boost. Visit mev-boost on further details on how to connect those twos.


Now you have set up your beacon client and validators. You launched them and they are working. How do you know that MEV extraction is working as intended?

On validator client. We want to see the following log. It should occur during start-up and every epoch

Submitted builder validator registration settings for custom builders


{"backend:null,"duration:9487420858,"message:"gRPC request finished.","method:"/ethereum.eth.v1alpha1.BeaconNodeValidator/SubmitValidatorRegistration,"severity:"DEBUG}
{"message:"Submitted builder validator registration settings for custom builders,"prefix:"validator,"severity:"INFO}

On beacon client. We want to see the following logs when your validator proposes a block.

Retrieved header from builder
Retrieved full payload from builder


{"blockHash:"0x24fed5a50492d0592bdc974943931cd53ba713c35ec749baeb2dd75d10a0fb33,"feeRecipient:"0xd9a5179f091d85051d3c982785efd1455cec8699,"gasUsed:0,"message:"Retrieved header from builder,"prefix:"rpc/validator,"severity:"INFO,"slot:875293}
{"beaconStateRoot:"0xb91ad0e06759435225b9369de656282c43ef5e0b8a15f6cb7dec93431575412c,"message:"Computed state root,"prefix:"rpc/validator,"severity:"DEBUG}
{"blockHash:"0x24fed5a50492d0592bdc974943931cd53ba713c35ec749baeb2dd75d10a0fb33,"feeRecipient:"0xd9a5179f091d85051d3c982785efd1455cec8699,"gasUsed:0,"message:"Retrieved full payload from builder,"prefix:"rpc/validator,"severity:"INFO,"slot:875293,"txs:0}
{"blockRoot:"69124129eafae6d5b01aa43c8b7934e8d8ad79b0fbbdd0378f5808520c2d2642,"message:"Broadcasting block,"prefix:"rpc/validator,"severity:"DEBUG}

Congrats! With those logs, you have successfully tested MEV extraction with Prysm prototype. This is not the final product, we have many enhacements on the pipeline. We 'll give periodic updates along the way. If you run into any issues or have any questions. Please ping me @terencechain on TG or terence#0083 on Discord.

With issues and questions. Please open issues in respected repos: Prysm issue: MEV-boost issue Builder issue: