Using Caplin as validator

Running Erigon with Caplin as validator

Caplin 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

Run the following command to start Erigon with the embedded Caplin consensus layer with the beacon API on:

erigon \
  --datadir=/data/erigon \
  --chain=mainnet \
  --prune.mode=full \
  --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 \
  --chain=<NETWORK>
  --beacon.api=beacon,validator,builder,config,debug,events,node,lighthouse

Flags Explanation:

Execution Layer:
- --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

Download the latest Lighthouse binary:

curl -LO https://github.com/sigp/lighthouse/releases/latest/download/lighthouse
chmod +x lighthouse
sudo mv lighthouse /usr/local/bin/

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 consensus layer:

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