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Configure Teku to use a builder network

You can connect to a builder network to generate execution payloads for the consensus client.

The builder recommends new blocks that are validated by the consensus client. If the builder goes down, the local execution client proposes a block instead.

To configure Teku to use a builder network:

1. Enable blinded block production​

Enable blinded block production using the --validators-proposer-blinded-blocks-enabled command line option.

note

If --validators-builder-registration-default-enabled is set to true, then --validators-proposer-blinded-blocks-enabled is automatically enabled.

2. Specify the builder endpoint​

Specify the builder endpoint using the --builder-endpoint command line option.

Example
--builder-endpoint="https://builder-relay-sepolia.flashbots.net/"

View the list of relay endpoints for available endpoints.

You can also use external software such as MEV-Boost to connect to multiple relays.

Example
--builder-endpoint=http://127.0.0.1:18550

3. Register the validator​

You must register your validator with the builder before proposing a block. Enable registration for all validators using the --validators-builder-registration-default-enabled command line option.

To enable registration for specific validators only, use the --validators-proposal-config option and specify the enabled validators in the proposer_config field of the proposer configuration file.

proposerConfig.json
{
  "proposer_config": {
    "0xa057816155ad77931185101128655c0191bd0214c201ca48ed887f6c4c6adf334070efcd75140eada5ac83a92506dd7a": {
      "fee_recipient": "0x50155530FCE8a85ec7055A5F8b2bE214B3DaeFd3",
      "builder": {
        "enabled": true,
        "gas_limit": "12345654321"
      }
    }
  },
  "default_config": {
    "fee_recipient": "0x6e35733c5af9B61374A128e6F85f553aF09ff89A",
    "builder": {
      "enabled": false
    }
  }
}

In this example, validator 0xa057816... is registered with the builder, but any validator using the default configuration isn't.

note

If you use a proposer configuration, you must enable blinded block production using --validators-proposer-blinded-blocks-enabled.

Example builder configurations​

Validator client and beacon node in a single process
teku \
    --validators-proposer-default-fee-recipient="0x6e35733c5af9B61374A128e6F85f553aF09ff89A" \
    --ee-endpoint="http://127.0.0.1:8551"                  \
    --ee-jwt-secret-file="/etc/jwt-secret.hex"             \
    --validators-builder-registration-default-enabled=true \
    --builder-endpoint="http://127.0.0.1:18550"
Validator client parameters
teku validator-client \
    --validators-proposer-blinded-blocks-enabled=true \
    --validators-proposer-config="/etc/teku/proposerConfig.json"
Proposer configuration
{
  "proposer_config": {
    "0xa057816155ad77931185101128655c0191bd0214c201ca48ed887f6c4c6adf334070efcd75140eada5ac83a92506dd7a": {
      "fee_recipient": "0x50155530FCE8a85ec7055A5F8b2bE214B3DaeFd3"
    }
  },
  "default_config": {
    "fee_recipient": "0x6e35733c5af9B61374A128e6F85f553aF09ff89A",
    "builder": {
      "enabled": true
    }
  }
}
Beacon node parameters
teku \
    --validators-proposer-default-fee-recipient="0x6e35733c5af9B61374A128e6F85f553aF09ff89A" \
    --ee-endpoint="http://127.0.0.1:8551" \
    --ee-jwt-secret-file="/etc/jwt-secret.hex" \
    --builder-endpoint="http://127.0.0.1:18550"