useBlockNumber

The useBlockNumber hook provides access to the current block number of the connected chain with real-time updates.

Import

import { useBlockNumber } from '@luno-kit/react'

Usage

index.tsx

import { useBlockNumber } from '@luno-kit/react'

function BlockNumberDisplay() {
  const { data: blockNumber, isLoading, error } = useBlockNumber()
  
  if (isLoading) {
    return <div>Loading block number...</div>
  }
  
  if (error) {
    return <div>Error: {error.message}</div>
  }
  
  if (!blockNumber) {
    return <div>No block number available</div>
  }
  
  return (
    <div>
      <h3>Current Block</h3>
      <p>Block Number: {blockNumber.toString()}</p>
    </div>
  )
}

config.ts

import { createConfig } from '@luno-kit/react'
import { polkadot, kusama } from '@luno-kit/react/chains'
import { polkadotjsConnector } from '@luno-kit/react/connectors'

const config = createConfig({
  appName: 'luno with-vite example',
  chains: [polkadot, kusama],
  connectors: [polkadotjsConnector()],
  autoConnect: true,
});

Return Value

The hook returns an object with the following properties:

Property	Type	Description
data	number | undefined	Current block number from the chain
error	Error | undefined	Any error that occurred during subscription
isLoading	boolean	Whether the subscription is currently loading

TIP

The block number automatically updates in real-time as new blocks are produced on the chain. useBlockNumber internally uses useSubscription to subscribe to block number updates from the chain.

Related Hooks

• useRuntimeVersion - Get runtime version information
• useGenesisHash - Get genesis hash information
• useSs58Format - Get SS58 format information
• useSubscription - Base hook for subscriptions