Builder Hub · ZCU Mainnet

Build on a chain that pays attention to you

Zero Chill Units is an EVM chain — a go-ethereum fork running Scrypt proof-of-work with AuxPoW merged mining and a node-authentication certificate layer. Every value on this page is taken from a live mainnet node, so it matches production exactly.

Chain specs

Network facts

Pin these values. A mismatched chain ID or genesis hash means your node silently forks itself onto a network of one.

Network: Zero Chill Units Mainnet
Chain ID / Network ID: 90031273
Currency symbol: ZCU
Genesis hash: 0x5955f084185288486e2917322958294b47e4a94156f4d02bbb918dfdadcd515a
Client: Geth v1.10.26-stable (0060dcca)
Consensus: Scrypt PoW + AuxPoW merged mining
P2P port: 31347/tcp (discovery disabled)
Public RPC: https://node-zcu.honest.money
Explorer: https://scan.zerochill.com
Required coinbase: 0xe3Aa1b921b0865E4092EB2CE2672Fcac3990Bdfe

Step 1

Connect a wallet

Add ZCU Mainnet as a custom EVM network in MetaMask, Rabby, or anything else that speaks JSON-RPC.

network config

Network name: Zero Chill Units Mainnet
New RPC URL: https://node-zcu.honest.money
Chain ID: 90031273
Currency symbol: ZCU
Block explorer URL: https://scan.zerochill.com

Any EVM wallet

Custom network → paste the config → done. Balances, sends, and contract calls behave exactly like Ethereum.

Standard tooling

Point Hardhat, Foundry, ethers or viem at https://node-zcu.honest.money and deploy Solidity unchanged.

Or run your own RPC

Public RPC is fine to start. For production, run a node and keep RPC on loopback behind your own proxy.

MetaMask · step by step

Add ZCU to MetaMask

1
Open the network switcher
In the MetaMask extension, click the network name at the top-left of the wallet (it usually reads “Ethereum Mainnet”). On mobile, tap the hamburger menu, then the current network.
2
Choose “Add a custom network”
Select “Add network”, then “Add a network manually” / “Add a custom network” at the bottom of the list. That opens a form with five fields.
3
Fill in the ZCU Mainnet values
Copy each value exactly — a wrong chain ID silently puts your wallet on a different network.
Network name
Zero Chill Units Mainnet
New RPC URL
https://node-zcu.honest.money
Chain ID
90031273
Currency symbol
ZCU
Block explorer URL
https://scan.zerochill.com
4
Save, then switch to it
Click “Save”. MetaMask verifies the RPC responds and that the chain ID it reports matches 90031273. Then pick “Zero Chill Units Mainnet” in the network switcher.
5
Confirm you're on the real chain
Your account address is identical to Ethereum — the same seed phrase controls it. Open the explorer at scan.zerochill.com and search your address to confirm the wallet and the chain agree on your balance and nonce.
6
Receive and send ZCU
ZCU is the native gas token, so sends work exactly like ETH: paste a 0x address, enter an amount, confirm. Gas is paid in ZCU, and any ERC-20 you deploy can be added with “Import tokens”.

Troubleshooting: “Chain ID mismatch” means the RPC URL is wrong or unreachable — re-check it against https://node-zcu.honest.money. If ZCU balances show as ETH, you left the currency symbol blank. MetaMask will not let two networks share chain ID 90031273, so delete any older ZCU entry before adding this one.

Step 2

Talk to the chain

Three calls confirm you're on the canonical ZCU mainnet before you write a line of contract code.

bash

# chain id (should return 0x55d4529 = 90031273)
curl -s https://node-zcu.honest.money \
  -H 'content-type: application/json' \
  -d '{"jsonrpc":"2.0","id":1,"method":"eth_chainId","params":[]}'

# latest block height
curl -s https://node-zcu.honest.money \
  -H 'content-type: application/json' \
  -d '{"jsonrpc":"2.0","id":1,"method":"eth_blockNumber","params":[]}'

# genesis hash — must match the value in Network facts
curl -s https://node-zcu.honest.money \
  -H 'content-type: application/json' \
  -d '{"jsonrpc":"2.0","id":1,"method":"eth_getBlockByNumber","params":["0x0",false]}'

Step 3

Run your own node

There are no published release binaries yet — you compile the fork. The full, production-exact runbook lives on the node docs: build script, directory layout and genesis, static peers, the systemd unit, verification checks, RPC exposure, node certificates, and a DigitalOcean droplet walkthrough.

Node runbook · nodes.honest.money

Guided, copy-paste node setup

Build zcu-geth from source on Ubuntu 22.04 / 24.04 (amd64).
Exact genesis.json — its hash must match Network facts.
Static peers, P2P on 31347, discovery disabled.
systemd unit, log locations, and sync verification.
Published node certificate + root public key install.
DigitalOcean droplet variant with public-IP advertising.

nodes.honest.money

Miners

Merged mining (AuxPoW)

ZCU is Scrypt-mined and supports AuxPoW, so it can be merge-mined alongside other Scrypt chains. The fork exposes a scrypt RPC namespace — enable it with --http.api ...,scrypt.

scrypt_createAuxBlock

Returns a work unit for the pool.

scrypt_submitAuxBlock

Submits the merged-mined solution.

Blocks must pay the required coinbase 0xe3Aa1b921b0865E4092EB2CE2672Fcac3990Bdfe from height 1 onward — enforced by the genesis Scrypt config.

Why ZCU

Why build here

EVM, without the toll booth

ZCU is a go-ethereum fork, so Solidity, Hardhat, Foundry, ethers, viem, MetaMask and Rabby all just work. No new language, no new tooling, no congestion tax.

Real proof of work

Scrypt PoW with AuxPoW merged mining — ZCU can be mined alongside other Scrypt chains, so security comes from hash power that already exists.

Authenticated nodes

A certificate layer keeps the peer set honest: every node presents a signed cert checked against the published root key. Open to join, hostile to spam.

Proof of Play runs on ZCU. See the games the chain already powers.