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Version: v0.16.0

Run a cluster with MEV-Boost


Charon is in an alpha state and should be used with caution according to its Terms of Use.

Charon's integration with MEV-Boost is also in an alpha state and requires a non-trivial amount of configuration to get working successfully. In the future, this process aims to be much more automated and seamless from a user's perspective.

This quickstart guide focuses on configuring the builder API for Charon and supported Validator clients.

Getting started with Charon & the Builder API

Running a distributed validator cluster with the builder API enabled will give the validators in the cluster access to the builder network. This builder network is a network of "Block Builders" who work with MEV searchers to produce the most valuable blocks a validator can propose.

MEV-Boost is one such product from flashbots that enables you to ask multiple block relays (who communicate with the "Block Builders") for blocks to propose. The block that pays the largest reward to the validator will be signed and returned to the relay for broadcasting to the wider network. The end result for the validator is generally an increased APY as they receive some share of the MEV.

Run MEV Boost

Currently, we don't support mev-boost if you are running your charon cluster using this repo since the repo uses lodestar validator client which is not builder API compatible with Charon.

We are working on a solution that enables the builder API feature irrespective of the choice of the Validator Client.

Builder API

If you want to configure Charon and supported Validator clients to support the builder API feature, you can do that as well.

Currently, Charon with the builder API enabled, is compatible only with Teku. Work is underway to support all validator client implementations in a mev-enabled distributed validator cluster seamlessly.


Charon supports builder API with the --builder-api flag. To use builder API, one simply needs to add this flag to the charon run command:

charon run --builder-api

Validator Clients

Teku Validator Client

Configuring the Teku validator client with Charon can be done by following the same process outlined in the Teku official guide.

The validator client must be set up to use the --validators-proposer-config flag with a value equal to http://$CHARON_ENDPOINT:3600/teku_proposer_config.

Once the flag is set up, Obol distributed validators will be able to register to the builder network, submit blinded beacon blocks and gain a share of the MEV profits.

Lighthouse Validator Client

For Lighthouse, we are currently waiting on the following PR to be merged into their unstable branch to enable compatability, please review the PR's status.

Verify MEV Boost is functional

Once you have executed the above steps, you can verify if your setup is functional by reviewing your proposed blocks on dashboards or via the Relay API endpoints.


Note that the mainnet block in the below description is taken only for representation, and not actually proposed by a distributed validator.

As an example, if my validator was the block proposer for block 17370078 on mainnet, I can review the following resources:

    • Consider this Mainnet block 17370078.
    • If we check the Block Extra Data field under Execution Payload, we will see the tag Illuminate Dmocratize Dstribute (Hex:0x496c6c756d696e61746520446d6f63726174697a6520447374726962757465).
    • Relays will generally add a tag to the block. Since this block was submitted via the Flashbots Relay, as a result it has the tag.
    • All mainnet flashbots blocks have this tag Illuminate Dmocratize Dstribute.
  • Relay API:
    • If you navigate to the Data API section on the Relay API page, you will see an endpoint labeled /relay/v1/data/bidtraces/proposer_payload_delivered.
    • You can add a query argument of block_number to this call to see if a block was submitted via that Relay.
    • Here is the query for the example block 17370078.
    • Blocks that have not been submitted to the Relay will return an empty array [].