Network Configuration

Setting	Value
Network name	NetZero Testnet
Chain ID	`20500` (`0x5014`)
Network ID	`20500`
Currency symbol	`USDn`
Currency decimals	18
Block time	3 seconds
Finality	1 block (7-of-10 validator votes)
Public RPC	`http://165.227.236.60` (HTTP) · `ws://165.227.236.60/ws` (WebSocket)
Local node RPC	`http://127.0.0.1:8545`
Local node WebSocket	`ws://127.0.0.1:8546`
Genesis hash	`0x347a85f05266dc87e3b627e0a077516b974a68e6c28b45a5ef101fefade3b975`
EVM level	Shanghai (PUSH0, EIP-1559 fees); the withdrawals list carries mining shares, not beacon-chain withdrawals

Add to MetaMask

Settings → Networks → Add network manually:

Network name: NetZero Testnet
RPC URL: http://165.227.236.60 (or http://127.0.0.1:8545 for your own node)
Chain ID: 20500
Currency symbol: USDn
Block explorer: the Explorer on this site

MetaMask will show gas in USDn. Because USDn is a dollar, the fee it shows is the fee in dollars.

Programmatic add (EIP-3085)

await window.ethereum.request({
  method: "wallet_addEthereumChain",
  params: [{
    chainId: "0x5014",
    chainName: "NetZero Testnet",
    nativeCurrency: { name: "USDn", symbol: "USDn", decimals: 18 },
    rpcUrls: ["http://165.227.236.60"],
  }],
});

RPC namespaces

Namespace	Where	Purpose
`eth`, `net`, `web3`, `txpool`	public and local	Standard Ethereum JSON-RPC
`nzc`	public and local	Validators, finality, votes, engine parameters (reference)
`agent`	local only	Key-free wallet, mining and transaction API for agents

A node refuses to start if agent (or personal, miner, admin, debug) would be served on a non-loopback address, unless explicitly overridden. Public RPC providers therefore never expose them.

System addresses

Address	Role
`0x0000000000000000000000000000000000001006`	Fee sink: coinbase of every block, swept to zero by the engine each block
`0x0000000000000000000000000000000000001001`	Carbon Fund: receives 50% of all fees
`0x0000000000000000000000000000000000001002`	Incentive Pool: pays 0.05 USDn per block into the miner pool (to the proposer when a block carries no shares)

These are plain accounts on the testnet. The mainnet design puts contracts behind them (see Roadmap).