Using Caplin as Validator

Running Erigon with Caplin as validator

Caplin, the Erigon embedded Consensus Layer, is also suitable for staking. However, it is required to pair it with a validator key manager, such as Lighthouse or Teku, since it doesn't have a native key management system.

This guide explains how to use Erigon with its embedded Caplin consensus layer and Lighthouse as the validator client for staking on Ethereum.

1. Start Erigon with Caplin

The following command starts Erigon with the embedded Caplin consensus layer with the beacon API on:

erigon \
  --datadir=/data/erigon \
  --http \
  --http.addr=0.0.0.0 \
  --http.port=8545 \
  --http.api=engine,eth,net,web3 \
  --ws \
  --ws.port=8546 \
  --caplin.enable-upnp \
  --caplin.discovery.addr=0.0.0.0 \
  --caplin.discovery.port=4000 \
  --caplin.discovery.tcpport=4001 \
  --beacon.api=beacon,validator,builder,config,debug,events,node,lighthouse 

Flags Explanation:

• Execution Layer (Erigon):

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

  • --ws: enables WebSocket-based communication (optional).

• Consensus Layer (Caplin):

  • --caplin.discovery.addr and --caplin.discovery.port: configures Caplin's gossip and discovery layer.

  • --beacon.api=beacon,validator,builder,config,debug,events,node,lighthouse: enables all possible API endpoints for the validator client.

2. Set Up Lighthouse Validator Client

2.1 Install Lighthouse

Install and run Lighthouse by following the official guide at https://lighthouse-book.sigmaprime.io/installation.html or use Docker:

docker pull sigp/lighthouse:latest

2.2. Create Lighthouse Validator Key Directory

mkdir -p ~/.lighthouse/validators

2.3. Run Lighthouse Validator Client

Start the validator client and connect it to the Caplin CL:

lighthouse vc \
  --network mainnet \
  --beacon-nodes http://127.0.0.1:5555 \
  --suggested-fee-recipient=<your_eth_address>

Flags Explanation:

• --network mainnet: Specifies the Ethereum mainnet.

• --beacon-nodes: Points to the Caplin beacon API at http://127.0.0.1:5555.

• --suggested-fee-recipient: Specifies your Ethereum address for block rewards.

2.4. Import Validator Keys

If you have existing validator keys, import them:

lighthouse account validator import --directory <path_to_validator_keys>