useChainId 
Hook for getting current chain ID.
Import 
ts
import { useChainId } from 'wagmi'Usage 
tsx
import { useChainId } from 'wagmi'
function App() {
  const chainId = useChainId()
}ts
import { http, createConfig } from 'wagmi'
import { mainnet, sepolia } from 'wagmi/chains'
export const config = createConfig({
  chains: [mainnet, sepolia],
  transports: {
    [mainnet.id]: http(),
    [sepolia.id]: http(),
  },
})Parameters 
ts
import { type UseChainIdParameters } from 'wagmi'config 
Config | undefined
Config to use instead of retrieving from the from nearest WagmiProvider.
tsx
import { useChainId } from 'wagmi'
import { config } from './config'
function App() {
  const chainId = useChainId({
    config,
  })
}ts
import { http, createConfig } from 'wagmi'
import { mainnet, sepolia } from 'wagmi/chains'
export const config = createConfig({
  chains: [mainnet, sepolia],
  transports: {
    [mainnet.id]: http(),
    [sepolia.id]: http(),
  },
})Return Type 
ts
import { type UseChainIdReturnType } from 'wagmi'number
Current chain ID from config.state.chainId.