useSendTransactionHash

The useSendTransactionHash hook provides functionality to send transactions to the blockchain and immediately return the transaction hash.

Import

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

Usage

Basic Usage

index.tsx

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

function SendTransactionHashButton() {
  const { api } = useApi();
  const { sendTransaction, isPending, error, data: txHash } = useSendTransactionHash()

  const handleSend = () => {
    const transferExtrinsic = api.tx.balances.transferKeepAlive(to, amount)

    sendTransaction({
      extrinsic: transferExtrinsic
    })
  }

  return (
    <div>
      <button onClick={handleSend} disabled={isPending}>
        {isPending ? 'Sending...' : 'Send Transaction'}
      </button>
      {error && <p>Error: {error.message}</p>}
      {txHash && <p>Transaction Hash: {txHash}</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,
});

Async Usage with Callbacks

AsyncTransactionHash.tsx

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

function AsyncTransactionHashButton() {
  const { api } = useApi();
  const { sendTransactionAsync, isPending } = useSendTransactionHash()

  const handleSendAsync = async () => {
    try {
      const transferExtrinsic = api.tx.balances.transferKeepAlive(to, amount)

      const txHash = await sendTransactionAsync({
        extrinsic: transferExtrinsic
      })

      console.log('Transaction hash:', txHash)
      // Note: This only returns the hash, not the final result
    } catch (error) {
      console.error('Transaction error:', error)
    }
  }

  return (
    <button onClick={handleSendAsync} disabled={isPending}>
      Send Transaction (Async)
    </button>
  )
}

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,
});

Parameters

The hook accepts an optional configuration object:

Parameter	Type	Required	Description
onSuccess	(data: HexString) => void	No	Callback when transaction hash is received
onError	(error: Error) => void	No	Callback when transaction fails
onSettled	() => void	No	Callback when transaction completes (success or failure)

Return Value

The hook returns an object with the following properties:

Methods

These are the functions you can call to send transactions.

Property	Type	Description
sendTransaction	(variables: { extrinsic: ISubmittableExtrinsic }, options?: { onSuccess?: () => void; onError?: (error: Error) => void; onSettled?: () => void }) => void	Send transaction synchronously
sendTransactionAsync	(variables: { extrinsic: ISubmittableExtrinsic }, options?: { onSuccess?: () => void; onError?: (error: Error) => void; onSettled?: () => void }) => Promise<HexString>	Send transaction asynchronously
reset	() => void	Reset the transaction state

Data & State

These properties provide information about the current state of the transaction.

Property	Type	Description
data	HexString | undefined	Transaction hash after sending
error	Error | null	Transaction error if any
isError	boolean	Whether there's an error
isIdle	boolean	Whether the hook is idle
isPending	boolean	Whether transaction is in progress
isSuccess	boolean	Whether transaction was successful
status	'idle' | 'pending' | 'error' | 'success'	Overall transaction status
variables	SendTransactionHashVariables | undefined	Last used transaction variables

Related Types

SendTransactionHashVariables

interface SendTransactionHashVariables {
  extrinsic: ISubmittableExtrinsic;  // The transaction to send
}

HexString

type HexString = `0x${string}`;  // Hexadecimal string starting with 0x

TIP

This hook is similar to useSendTransaction but returns the transaction hash immediately after the transaction is signed and sent, without waiting for the transaction to be included in a block or finalized. Use this when you only need the transaction hash.

WARNING

In Polkadot, transaction hashes are not guaranteed to be unique across the entire chain, although they are generally unique within a block. This means you cannot reliably query transaction information by hash alone. For more information, refer to the Polkadot.js documentation.

Related Hooks

• useSendTransaction - Send transaction with full status tracking
• useSignMessage - Sign messages with the connected account
• useSigner - Get transaction signer