Free Config Template — Updated April 2026

5 QBFT Settings That Make or Break Your Besu Network

Genesis config template + validator key setup guide. Includes the exact block time, epoch length, and gas settings we use for enterprise Besu deployments.

Besu defaults are for testnets, not production

QBFT ships with default settings optimized for local development. In production, wrong block period tanks throughput, wrong request timeout causes leader election storms, and the default gas limit (effectively unlimited) lets a single contract deployment DOS your network.

genesis.json — 4-Validator QBFT Network

{
  "config": {
    "chainId": 1337,
    "berlinBlock": 0,
    "qbft": {
      "blockperiodseconds": 2,
      "epochlength": 30000,
      "requesttimeoutseconds": 4
    }
  },
  "nonce": "0x0",
  "timestamp": "0x0",
  "gasLimit": "0x1312D00",
  "difficulty": "0x1",
  "mixHash": "0x63...",
  "coinbase": "0x0000000000000000000000000000000000000000",
  "alloc": {
    "0xfe3b557e8fb62b89f4916b721be55ceb828dbd73": {
      "balance": "0xad78ebc5ac6200000"
    }
  },
  "extraData": "0xf87aa00000...c0"
}

Get the complete template with validator keys

config.toml — Production Settings

# config.toml — Production settings
[Ethereum]
network-id = 1337

[Mining]
enabled = true
coinbase = "0xfe3b557e8fb62b89f4916b721be55ceb828dbd73"

[Metrics]
enabled = true
host = "0.0.0.0"
port = 9545

[P2P]
host = "0.0.0.0"
port = 30303
max-peers = 25

Get full config with all settings explained

Critical Settings

Config Templates

20+

Pre-flight Checks

What's inside

Block period tuning — latency vs throughput trade-offs (1s, 2s, 5s) with real benchmarks

Request timeout — exponential backoff math for cross-region deployments (10-15s rule)

Epoch length — validator set persistence, state recovery, and vote propagation timing

Gas limit — why the default is dangerous and the production baseline of 20M (0x1312D00)

Validator key management — extraData RLP encoding, key rotation runbook, BFT tolerance math

Complete genesis.json + config.toml templates for a 4-validator QBFT network

By David Viejo — CTO at KFS, 6+ years in blockchain infrastructure. Creator of Bevel Operator Fabric (Hyperledger Foundation).

Get the config templates

Enter your work email and we'll send you the complete genesis.json, config.toml, and the 20-item pre-flight checklist.

Copy-paste genesis.json for 4-validator QBFT

Production config.toml with inline docs

Validator key rotation runbook

Updated for Besu 25.x — includes latest QBFT protocol changes.