QELT Validator Node

Deploy your own QELT Mainnet validator node in minutes.

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🚀 Step-by-Step: Deploy Your Validator Node

Step 1 — Get a Server

You need a dedicated server (VPS or bare-metal) with:

Requirement	Minimum	Recommended
OS	Ubuntu 22.04 LTS	Ubuntu 24.04 LTS
RAM	8 GB	16 GB
CPU	4 cores	8 cores
Storage	100 GB SSD	500 GB NVMe
Network	100 Mbps, static IP	1 Gbps
Ports	30303 TCP+UDP open inbound	Same

Step 2 — Clone the Repository and Run the Installer

SSH into your server and run:

# Install git if not present
sudo apt update && sudo apt install -y git

# Clone the repository
git clone https://github.com/PRQELT/qelt-validator-node.git

# Enter the directory
cd qelt-validator-node

# Make the installer executable
chmod +x install-qelt-validator.sh

# Run the installer (requires root)
sudo bash install-qelt-validator.sh

The script is interactive and will guide you through 10 steps:

1. ✅ System checks (OS, RAM, disk, ports, bootnode connectivity)
2. ✅ Installing Java 21 + Hyperledger Besu 25.12.0 (SHA256 verified)
3. ✅ Creating a secure besu system user + directories
4. ✅ Deploying the QELT genesis configuration (SHA256 verified)
5. ✅ Generating (or importing) your validator key
6. ✅ Extracting your validator address + enode URL
7. ✅ Configuring the systemd service (with security hardening)
8. ✅ Optional: HTTPS RPC endpoint (nginx + Node.js middleware + SSL)
9. ✅ Firewall configuration (UFW)
10. ✅ Starting the node and verifying connectivity + sync

Step 3 — Wait for Full Sync

After installation, your node needs to sync with the network. This may take several hours.

Check sync status (returns false when fully synced):

curl -s -X POST --data '{"jsonrpc":"2.0","method":"eth_syncing","params":[],"id":1}' \
  http://127.0.0.1:8545 | jq .result

Compare your block with the network:

echo "Local:   $(curl -s -X POST --data '{"jsonrpc":"2.0","method":"eth_blockNumber","params":[],"id":1}' http://127.0.0.1:8545 | jq -r .result)"
echo "Network: $(curl -s -X POST --data '{"jsonrpc":"2.0","method":"eth_blockNumber","params":[],"id":1}' https://mainnet.qelt.ai | jq -r .result)"

When both numbers match, your node is fully synced.

Watch live sync progress:

sudo journalctl -u besu-qelt-validator -f

Step 4 — Email Your Validator Details

Once synced, the installer will have shown you a ready-to-copy email template. You can also find your details at any time:

cat /data/qelt/VALIDATOR_INFO.txt

📧 Send your Validator Address and Enode URL to: laurent@qxmp.ai

Include:

• Your Validator Address (e.g. 0x1c0dffbe7183984870283b4c1db121f4c44ba28b)
• Your Enode URL (e.g. enode://abc...@84.247.133.98:30303)
• Confirmation that your node is fully synced

Step 5 — Wait for Admission

The QELT team will coordinate a vote among existing validators. QBFT requires a majority (currently 4 of 7 validators) to vote.

Check if you've been admitted:

curl -s -X POST --data '{"jsonrpc":"2.0","method":"qbft_getValidatorsByBlockNumber","params":["latest"],"id":1}' \
  http://127.0.0.1:8545 | jq .result

When your address appears in the list — congratulations, you're a QELT validator! Your node begins participating in consensus automatically. No restart needed.

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📋 Network Information

Parameter	Value
Network Name	QELT Mainnet
Chain ID	770
Consensus	QBFT (Quorum Byzantine Fault Tolerance)
Block Time	5 seconds
EVM Version	Cancun
Block Finality	Immediate (no reorgs)
Gas Limit	50,000,000
Client	Hyperledger Besu 25.12.0

Public RPC Endpoints

https://mainnet.qelt.ai       — Validator 1 (Bootnode)
https://mainnet2.qelt.ai      — Validator 2
https://mainnet3.qelt.ai      — Validator 3
https://mainnet4.qelt.ai      — Validator 4
https://mainnet5.qelt.ai      — Validator 5
https://archivem.qelt.ai      — Archive Node (full history)

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🛠️ Common Commands

# Service management
sudo systemctl status besu-qelt-validator    # Check status
sudo systemctl restart besu-qelt-validator   # Restart
sudo systemctl stop besu-qelt-validator      # Stop
sudo journalctl -u besu-qelt-validator -f    # Live logs

# Network queries (via local RPC)
curl -s -X POST --data '{"jsonrpc":"2.0","method":"eth_blockNumber","params":[],"id":1}' \
  http://127.0.0.1:8545 | jq -r .result

curl -s -X POST --data '{"jsonrpc":"2.0","method":"net_peerCount","params":[],"id":1}' \
  http://127.0.0.1:8545 | jq -r .result

curl -s -X POST --data '{"jsonrpc":"2.0","method":"eth_syncing","params":[],"id":1}' \
  http://127.0.0.1:8545 | jq .result

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📁 Files Created by the Installer

File	Purpose
/data/qelt/	Blockchain data directory
/data/qelt/keys/nodekey	Your validator private key (back this up!)
/data/qelt/static-nodes.json	Bootnode peer entry
/data/qelt/VALIDATOR_INFO.txt	Summary of your node details
/etc/qelt/genesis.json	Network genesis configuration
/etc/systemd/system/besu-qelt-validator.service	Systemd service
/opt/besu/	Besu binary installation

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🔐 Security Features

The installer implements production security best practices:

• Dedicated system user (besu) — the node daemon never runs as root
• Systemd sandboxing — ProtectHome, ProtectSystem=strict, NoNewPrivileges, PrivateTmp
• Strict key permissions — chmod 600 on node private key, chmod 700 on keys directory
• RPC localhost-only by default — not exposed to the internet
• SHA256 verification of both the Besu binary and genesis file
• UFW firewall configuration (30303 TCP/UDP for P2P)
• Node.js RPC middleware with method whitelisting (if public RPC is enabled)
• Nginx rate limiting + security headers (if HTTPS endpoint is enabled)

⚠️ Protect Your Node Key

Your node key (/data/qelt/keys/nodekey) is your validator identity.

• Back it up securely — if lost, you lose your validator slot
• Never share your private key — if stolen, someone can sign blocks as you

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🔄 Updating

Updating the Installer

cd /root/qelt-validator-node
git pull

Updating Besu

When a new Besu version is approved by the QELT team:

sudo systemctl stop besu-qelt-validator
# Download and extract the new version (update URL)
sudo rm -rf /opt/besu
sudo mkdir -p /opt/besu
sudo tar -xzf besu-NEW_VERSION.tar.gz -C /opt/besu --strip-components=1
sudo ln -sf /opt/besu/bin/besu /usr/local/bin/besu
besu --version  # Verify
sudo systemctl start besu-qelt-validator

⚠️ Always check Besu release notes for breaking changes before upgrading.

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🆘 Troubleshooting

Node won't start

sudo journalctl -u besu-qelt-validator --no-pager -n 50

Common causes: port 30303 already in use, insufficient RAM, wrong genesis, key permissions.

No peers connecting

sudo ss -tlnp | grep 30303       # Check port is open
sudo ufw status | grep 30303     # Check firewall

Sync stuck at block 0

• Verify genesis file: sha256sum /etc/qelt/genesis.json — compare with any active validator to confirm match
• Check bootnode enode URL in service file
• Ensure outbound + inbound traffic on port 30303

View your validator details

cat /data/qelt/VALIDATOR_INFO.txt
besu public-key export-address --node-private-key-file=/data/qelt/keys/nodekey

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📖 Additional Documentation

Document	Description
VALIDATOR_ADMISSION.md	Complete admission process — for both new operators and existing validators

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📬 Contact

• Validator admission requests: laurent@qxmp.ai
• Besu docs: https://besu.hyperledger.org/
• QBFT consensus: https://besu.hyperledger.org/stable/private-networks/how-to/configure/consensus/qbft

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License

MIT License — Copyright 2026 QELT Network

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Built for the QELT Validator Expansion Program.