Validator Documentation

This page focuses on the pieces that are Lumen-specific (chain id, denom, genesis source, and fee rules). For deeper ops tooling and scripts, use the Validator Kit. For the most complete reference, see the blockchain docs.

Blockchain validator guide: https://github.com/network-lumen/blockchain/blob/master/docs/validators.md

Quick Facts

Chain id: lumen
Bech32 prefix: lmn
Base denom: ulmn (1 LMN = 1,000,000 ulmn)
Gasless chain: tx fee must be exactly 0 (use --fees="0ulmn" when submitting tx)

Prerequisites

Hardware: 4+ CPU, 16GB+ RAM, SSD storage, stable network
Linux admin basics (systemd, firewall, logs)
Minimum stake: 1 LMN (1,000,000 ulmn) is typically ~1 voting power (Cosmos default power reduction)

Setup

1) Install and build `lumend`

sudo apt update && sudo apt upgrade -y
sudo apt install build-essential git curl -y

git clone https://github.com/network-lumen/blockchain
cd blockchain
make install

lumend version

2) Init with the correct chain id

MONIKER="your-validator-name"
lumend init "$MONIKER" --chain-id lumen

3) Install genesis (source of truth)

curl -L https://raw.githubusercontent.com/network-lumen/validator-kit/master/config/genesis.json > ~/.lumen/config/genesis.json

4) Configure gasless settings

Lumen nodes should run with --minimum-gas-prices 0ulmn (non-zero values are rejected).

Edit ~/.lumen/config/app.toml:

minimum-gas-prices = ""

Important: transactions must still set a zero fee (example: --fees="0ulmn").

5) Run as a systemd service

sudo tee /etc/systemd/system/lumend.service > /dev/null <<EOF
[Unit]
Description=Lumen Node
After=network.target

[Service]
User=$USER
ExecStart=$(which lumend) start --minimum-gas-prices 0ulmn
Restart=on-failure
RestartSec=3
LimitNOFILE=4096

[Install]
WantedBy=multi-user.target
EOF

sudo systemctl enable lumend
sudo systemctl start lumend
sudo journalctl -u lumend -f

Create a validator

Once synced:

lumend tx staking create-validator \
  --amount=1000000ulmn \
  --pubkey=$(lumend tendermint show-validator) \
  --moniker="$MONIKER" \
  --chain-id=lumen \
  --fees="0ulmn" \
  --from=<your-key-name>

Delegation / Undelegation

lumend tx staking delegate <validator-address> 1000000ulmn \
  --from=<your-key-name> \
  --chain-id=lumen \
  --fees="0ulmn"

lumend tx staking unbond <validator-address> 1000000ulmn \
  --from=<your-key-name> \
  --chain-id=lumen \
  --fees="0ulmn"

Troubleshooting

Validator jailed

lumend tx slashing unjail \
  --from=<your-key-name> \
  --chain-id=lumen \
  --fees="0ulmn"

Resources

Validator Kit: https://github.com/network-lumen/validator-kit
Blockchain: https://github.com/network-lumen/blockchain

Validator Kit docs:

How to become a validator: https://github.com/network-lumen/validator-kit/blob/master/ops/become_validator.md
Stake bootstrap & decentralization: https://github.com/network-lumen/validator-kit/blob/master/ops/stake_bootstrap.md
Validator & sentry specifications: https://github.com/network-lumen/validator-kit/blob/master/ops/validator_specs.md
Learn folder: https://github.com/network-lumen/validator-kit/tree/master/learn

LUMEN NETWORK

Validator Guide