The chainLib runs on.

import { createPublicClient, defineChain, http } from 'viem'

export const libTestnet = defineChain({
  id: 54210,
  name: 'Lib Testnet',
  nativeCurrency: { name: 'Lib Test Coin', symbol: 'tLIB', decimals: 18 },
  rpcUrls: { default: { http: ['https://rpc-testnet.libchain.tech'] } },
  blockExplorers: { default: { name: 'Lib Explorer', url: 'https://testnet.libchain.tech' } },
})

const client = createPublicClient({ chain: libTestnet, transport: http() })
console.log(await client.getBlockNumber())

import { JsonRpcProvider } from 'ethers'

const provider = new JsonRpcProvider('https://rpc-testnet.libchain.tech', 54210)
console.log(await provider.getBlockNumber())

# deploy a contract
forge create src/Hello.sol:Hello \
  --rpc-url https://rpc-testnet.libchain.tech \
  --private-key $PRIVATE_KEY --broadcast

# read the chain
cast block-number --rpc-url https://rpc-testnet.libchain.tech

// hardhat.config.ts
export default {
  solidity: '0.8.24',
  networks: {
    libTestnet: {
      url: 'https://rpc-testnet.libchain.tech',
      chainId: 54210,
      accounts: [process.env.PRIVATE_KEY!],
    },
  },
}