useChainId

Hook for getting current chain ID.

Import

import { useChainId } from 'wagmi'

Usage

index.tsx

import { useChainId } from 'wagmi'

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(),
  },
})

Parameters

import { type UseChainIdParameters } from 'wagmi'

config

Config | undefined

Config to use instead of retrieving from the nearest WagmiProvider.

index.tsx

import { useChainId } from 'wagmi'
import { config } from './config'

function App() {
  const chainId = useChainId({
    config,
  })
}

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

import { type UseChainIdReturnType } from 'wagmi'

number

Current chain ID from config.state.chainId.

INFO

Only returns chain IDs for chains configured via createConfig's chains parameter.

If the active connection chainId is not from a chain included in your Wagmi Config, useChainId will return the last configured chain ID.

Action

• getChainId
• watchChainId