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watchPendingTransactions

Watches and returns pending transaction hashes.

This Action will batch up all the pending transactions found within the pollingInterval, and invoke them via onTransactions.

Usage

example.ts
import { publicClient } from './client'
 
const unwatch = publicClient.watchPendingTransactions( 
  { onTransactions: hashes => console.log(hashes) }
)

> ['0x...', '0x...', '0x...']
 
> ['0x...', '0x...']
 
> ['0x...', '0x...', '0x...', ...]

Returns

UnwatchFn

A function that can be invoked to stop watching for new pending transaction hashes.

Parameters

onTransactions

  • Type: (hashes: '0x${string}'[]) => void

The new pending transaction hashes.

const unwatch = publicClient.watchPendingTransactions(
  { onTransactions: hashes => console.log(hashes) } 
)

batch (optional)

  • Type: boolean
  • Default: true

Whether or not to batch the transaction hashes between polling intervals.

const unwatch = publicClient.watchPendingTransactions(
  { 
    batch: false, 
    onTransactions: hashes => console.log(hashes),
  }
)

onError (optional)

  • Type: (error: Error) => void

Error thrown from listening for new pending transactions.

const unwatch = publicClient.watchPendingTransactions(
  { 
    onError: error => console.log(error), 
    onTransactions: hashes => console.log(hashes),
  }
)

poll (optional)

  • Type: boolean
  • Default: false for WebSocket Clients, true for non-WebSocket Clients

Whether or not to use a polling mechanism to check for new pending transactions instead of a WebSocket subscription.

This option is only configurable for Clients with a WebSocket Transport.

import { createPublicClient, webSocket } from 'viem'
import { mainnet } from 'viem/chains'
 
const publicClient = createPublicClient({
  chain: mainnet,
  transport: webSocket()
})
 
const unwatch = publicClient.watchPendingTransactions(
  { 
    onTransactions: transactions => console.log(transactions),
    poll: true, 
  }
)

pollingInterval (optional)

  • Type: number

Polling frequency (in ms). Defaults to the Client's pollingInterval config.

const unwatch = publicClient.watchPendingTransactions(
  { 
    pollingInterval: 1_000, 
    onTransactions: hashes => console.log(hashes),
  }
)

JSON-RPC Methods