Using an external consensus client as validator

To use an external Consensus Layer (CL) it is necessary to add to Erigon the flag --externalcl. Here are a couple of examples on how to configure Lighhouse and Prysm to run along with Erigon:

• Ethereum

• Gnosis Chain

Once you have Erigon and a CL client up and running, you can proceed to set up a Validator Client (VC). The VC is responsible for managing your keys and signing valid blocks.

Getting Started with a Validator Client

To set up a VC, follow the instructions provided in the official documentation, such as:

https://lighthouse-book.sigmaprime.io/mainnet-validator.html.

This guide will walk you through the process of setting up a VC, including:

• Generating and managing your keys

• Configuring the Validator Client

• Signing valid blocks

Make sure to follow the instructions carefully and thoroughly to ensure that your VC is set up correctly. It is always recommended to start staking with a testnet.

Example of configuration

The following example demonstrates how to configure Erigon to run with an external Consensus Layer:

erigon \
  --externalcl \
  --datadir=/data/erigon \
  --chain=sepolia \
  --authrpc.jwtsecret=/jwt
  --authrpc.addr=0.0.0.0 \
  --http \
  --http.addr=0.0.0.0 \
  --http.port=8545 \
  --http.api=engine,eth,net,web3 \
  --ws \
  --ws.port=8546 \

Flags explanation:

• --externalcl: Enables the use of an external CL.

• --datadir=/data/erigon: Defines the directory to be used for databases.

• --chain=sepolia: Specifies the Sepolia chain.

• --authrpc.jwtsecret=/jwt: Sets the location of the JWT authentication code in hex encoding. This is used by Erigon (the EL) and the CL (in this case Lighthouse) to authenticate communication.

• --authrpc.addr=0.0.0.0: Allows the engine API to be accessed from any address.

• --http.api=engine,eth,net,web3: Enables the necessary APIs for external clients and Caplin.

• --ws: enables WebSocket-based communication, which is optional.

Note that many pre-merge flags, such as --miner.etherbase, are no longer useful, as block rewards and other validator-related configurations are now controlled by the Consensus Layer (CL).