getChainId 
Returns the chain ID associated with the current network
Usage 
ts
import { publicClient } from './client'
const block = await publicClient.getChainId() 
// 1
ts
import { createPublicClient, http } from 'viem'
import { mainnet } from 'viem/chains'
export const publicClient = createPublicClient({
  chain: mainnet,
  transport: http()
})
Returns 
number
The current chain ID.
JSON-RPC Method 
- Calls 
eth_chainId.