useWatchContractEvent

Hook that watches and returns emitted contract event logs.

Import

import { useWatchContractEvent } from 'wagmi'

Usage

index.tsx

import { useWatchContractEvent } from 'wagmi'
import { abi } from './abi'

function App() {
  useWatchContractEvent({
    address: '0x6b175474e89094c44da98b954eedeac495271d0f',
    abi,
    eventName: 'Transfer',
    onLogs(logs) {
      console.log('New logs!', logs)
    },
  })
}

abi.ts

export const abi = [
  {
    type: 'event',
    name: 'Approval',
    inputs: [
      { indexed: true, name: 'owner', type: 'address' },
      { indexed: true, name: 'spender', type: 'address' },
      { indexed: false, name: 'value', type: 'uint256' },
    ],
  },
  {
    type: 'event',
    name: 'Transfer',
    inputs: [
      { indexed: true, name: 'from', type: 'address' },
      { indexed: true, name: 'to', type: 'address' },
      { indexed: false, name: 'value', type: 'uint256' },
    ],
  },
] as const

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 UseWatchContractEventParameters } from 'wagmi'

abi

Abi

The contract's ABI. Check out the TypeScript docs for how to set up ABIs for maximum type inference and safety.

index.tsx

import { useWatchContractEvent } from 'wagmi'
import { abi } from './abi'

function App() {
  useWatchContractEvent({
    address: '0x6b175474e89094c44da98b954eedeac495271d0f',
    abi,
    eventName: 'Transfer',
    onLogs(logs) {
      console.log('New logs!', logs)
    },
  })
}

abi.ts

export const abi = [
  {
    type: 'event',
    name: 'Approval',
    inputs: [
      { indexed: true, name: 'owner', type: 'address' },
      { indexed: true, name: 'spender', type: 'address' },
      { indexed: false, name: 'value', type: 'uint256' },
    ],
  },
  {
    type: 'event',
    name: 'Transfer',
    inputs: [
      { indexed: true, name: 'from', type: 'address' },
      { indexed: true, name: 'to', type: 'address' },
      { indexed: false, name: 'value', type: 'uint256' },
    ],
  },
] as const

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(),
  },
})

address

Address | undefined

The contract's address.

index.tsx

import { useWatchContractEvent } from 'wagmi'
import { abi } from './abi'

function App() {
  useWatchContractEvent({
    address: '0x6b175474e89094c44da98b954eedeac495271d0f',
    abi,
    eventName: 'Transfer',
    onLogs(logs) {
      console.log('New logs!', logs)
    },
  })
}

abi.ts

export const abi = [
  {
    type: 'event',
    name: 'Approval',
    inputs: [
      { indexed: true, name: 'owner', type: 'address' },
      { indexed: true, name: 'spender', type: 'address' },
      { indexed: false, name: 'value', type: 'uint256' },
    ],
  },
  {
    type: 'event',
    name: 'Transfer',
    inputs: [
      { indexed: true, name: 'from', type: 'address' },
      { indexed: true, name: 'to', type: 'address' },
      { indexed: false, name: 'value', type: 'uint256' },
    ],
  },
] as const

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(),
  },
})

args

object | readonly unknown[] | undefined

• Arguments to pass when calling the contract.
• Inferred from abi and eventName.

index.tsx

import { useWatchContractEvent } from 'wagmi'
import { abi } from './abi'

function App() {
  useWatchContractEvent({
    address: '0x6b175474e89094c44da98b954eedeac495271d0f',
    abi,
    args: {
      to: '0xd2135CfB216b74109775236E36d4b433F1DF507B'
    }
    eventName: 'Transfer',
    onLogs(logs) {
      console.log('New logs!', logs)
    },
  })
}

abi.ts

export const abi = [
  {
    type: 'event',
    name: 'Approval',
    inputs: [
      { indexed: true, name: 'owner', type: 'address' },
      { indexed: true, name: 'spender', type: 'address' },
      { indexed: false, name: 'value', type: 'uint256' },
    ],
  },
  {
    type: 'event',
    name: 'Transfer',
    inputs: [
      { indexed: true, name: 'from', type: 'address' },
      { indexed: true, name: 'to', type: 'address' },
      { indexed: false, name: 'value', type: 'uint256' },
    ],
  },
] as const

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(),
  },
})

batch

boolean | undefined

• Whether or not the events should be batched on each invocation.
• Defaults to true.

index.tsx

import { useWatchContractEvent } from 'wagmi'
import { abi } from './abi'

function App() {
  useWatchContractEvent({
    address: '0x6b175474e89094c44da98b954eedeac495271d0f',
    abi,
    batch: false,
    eventName: 'Transfer',
    onLogs(logs) {
      console.log('New logs!', logs)
    },
  })
}

abi.ts

export const abi = [
  {
    type: 'event',
    name: 'Approval',
    inputs: [
      { indexed: true, name: 'owner', type: 'address' },
      { indexed: true, name: 'spender', type: 'address' },
      { indexed: false, name: 'value', type: 'uint256' },
    ],
  },
  {
    type: 'event',
    name: 'Transfer',
    inputs: [
      { indexed: true, name: 'from', type: 'address' },
      { indexed: true, name: 'to', type: 'address' },
      { indexed: false, name: 'value', type: 'uint256' },
    ],
  },
] as const

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(),
  },
})

chainId

config['chains'][number]['id'] | undefined

ID of chain to use when fetching data.

index.tsx

import { useWatchContractEvent } from 'wagmi'
import { abi } from './abi'

function App() {
  useWatchContractEvent({
    address: '0x6b175474e89094c44da98b954eedeac495271d0f',
    abi,
    chainId: 1,
    eventName: 'Transfer',
    onLogs(logs) {
      console.log('New logs!', logs)
    },
  })
}

abi.ts

export const abi = [
  {
    type: 'event',
    name: 'Approval',
    inputs: [
      { indexed: true, name: 'owner', type: 'address' },
      { indexed: true, name: 'spender', type: 'address' },
      { indexed: false, name: 'value', type: 'uint256' },
    ],
  },
  {
    type: 'event',
    name: 'Transfer',
    inputs: [
      { indexed: true, name: 'from', type: 'address' },
      { indexed: true, name: 'to', type: 'address' },
      { indexed: false, name: 'value', type: 'uint256' },
    ],
  },
] as const

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(),
  },
})

config

Config | undefined

Config to use instead of retrieving from the nearest WagmiProvider.

index.tsx

import { useWatchContractEvent } from 'wagmi'
import { abi } from './abi'
import { config } from './config'

function App() {
  useWatchContractEvent({
    address: '0x6b175474e89094c44da98b954eedeac495271d0f',
    abi,
    config,
    eventName: 'Transfer',
    onLogs(logs) {
      console.log('New logs!', logs)
    },
  })
}

abi.ts

export const abi = [
  {
    type: 'event',
    name: 'Approval',
    inputs: [
      { indexed: true, name: 'owner', type: 'address' },
      { indexed: true, name: 'spender', type: 'address' },
      { indexed: false, name: 'value', type: 'uint256' },
    ],
  },
  {
    type: 'event',
    name: 'Transfer',
    inputs: [
      { indexed: true, name: 'from', type: 'address' },
      { indexed: true, name: 'to', type: 'address' },
      { indexed: false, name: 'value', type: 'uint256' },
    ],
  },
] as const

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(),
  },
})

eventName

string

• Event to listen for the contract.
• Inferred from abi.

index.tsx

import { useWatchContractEvent } from 'wagmi'
import { abi } from './abi'
import { config } from './config'

function App() {
  useWatchContractEvent({
    address: '0x6b175474e89094c44da98b954eedeac495271d0f',
    abi,
    eventName: 'Transfer',
    onLogs(logs) {
      console.log('New logs!', logs)
    },
  })
}

abi.ts

export const abi = [
  {
    type: 'event',
    name: 'Approval',
    inputs: [
      { indexed: true, name: 'owner', type: 'address' },
      { indexed: true, name: 'spender', type: 'address' },
      { indexed: false, name: 'value', type: 'uint256' },
    ],
  },
  {
    type: 'event',
    name: 'Transfer',
    inputs: [
      { indexed: true, name: 'from', type: 'address' },
      { indexed: true, name: 'to', type: 'address' },
      { indexed: false, name: 'value', type: 'uint256' },
    ],
  },
] as const

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(),
  },
})

onError

((error: Error) => void) | undefined

Error thrown from getting the block number.

index.tsx

import { useWatchContractEvent } from 'wagmi'
import { abi } from './abi'

function App() {
  useWatchContractEvent({
    address: '0x6b175474e89094c44da98b954eedeac495271d0f',
    abi,
    eventName: 'Transfer',
    onLogs(logs) {
      console.log('New logs!', logs)
    },
    onError(error) {
      console.log('Error', error)
    }
  })
}

abi.ts

export const abi = [
  {
    type: 'event',
    name: 'Approval',
    inputs: [
      { indexed: true, name: 'owner', type: 'address' },
      { indexed: true, name: 'spender', type: 'address' },
      { indexed: false, name: 'value', type: 'uint256' },
    ],
  },
  {
    type: 'event',
    name: 'Transfer',
    inputs: [
      { indexed: true, name: 'from', type: 'address' },
      { indexed: true, name: 'to', type: 'address' },
      { indexed: false, name: 'value', type: 'uint256' },
    ],
  },
] as const

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(),
  },
})

onLogs

(logs: Log[], prevLogs: Log[] | undefined) => void

Callback for when logs changes.

index.tsx

import { useWatchContractEvent } from 'wagmi'
import { abi } from './abi'

function App() {
  useWatchContractEvent({
    address: '0x6b175474e89094c44da98b954eedeac495271d0f',
    abi,
    eventName: 'Transfer',
    onLogs(logs) {
      console.log('New logs!', logs)
    }
  })
}

abi.ts

export const abi = [
  {
    type: 'event',
    name: 'Approval',
    inputs: [
      { indexed: true, name: 'owner', type: 'address' },
      { indexed: true, name: 'spender', type: 'address' },
      { indexed: false, name: 'value', type: 'uint256' },
    ],
  },
  {
    type: 'event',
    name: 'Transfer',
    inputs: [
      { indexed: true, name: 'from', type: 'address' },
      { indexed: true, name: 'to', type: 'address' },
      { indexed: false, name: 'value', type: 'uint256' },
    ],
  },
] as const

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(),
  },
})

poll

boolean | undefined

• Whether or not to use a polling mechanism to check for new blocks instead of a WebSocket subscription.
• Defaults to false for WebSocket Clients, and true for non-WebSocket Clients.

index.tsx

import { useWatchContractEvent } from 'wagmi'
import { abi } from './abi'

function App() {
  useWatchContractEvent({
    address: '0x6b175474e89094c44da98b954eedeac495271d0f',
    abi,
    eventName: 'Transfer',
    onLogs(logs) {
      console.log('New logs!', logs)
    },
    poll: true
  })
}

abi.ts

export const abi = [
  {
    type: 'event',
    name: 'Approval',
    inputs: [
      { indexed: true, name: 'owner', type: 'address' },
      { indexed: true, name: 'spender', type: 'address' },
      { indexed: false, name: 'value', type: 'uint256' },
    ],
  },
  {
    type: 'event',
    name: 'Transfer',
    inputs: [
      { indexed: true, name: 'from', type: 'address' },
      { indexed: true, name: 'to', type: 'address' },
      { indexed: false, name: 'value', type: 'uint256' },
    ],
  },
] as const

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(),
  },
})

pollingInterval

number | undefined

• Polling frequency (in milliseconds).
• Defaults to the Config's pollingInterval config.

index.tsx

import { useWatchContractEvent } from 'wagmi'
import { abi } from './abi'

function App() {
  useWatchContractEvent({
    address: '0x6b175474e89094c44da98b954eedeac495271d0f',
    abi,
    eventName: 'Transfer',
    onLogs(logs) {
      console.log('New logs!', logs)
    },
    pollingInterval: 1_000
  })
}

abi.ts

export const abi = [
  {
    type: 'event',
    name: 'Approval',
    inputs: [
      { indexed: true, name: 'owner', type: 'address' },
      { indexed: true, name: 'spender', type: 'address' },
      { indexed: false, name: 'value', type: 'uint256' },
    ],
  },
  {
    type: 'event',
    name: 'Transfer',
    inputs: [
      { indexed: true, name: 'from', type: 'address' },
      { indexed: true, name: 'to', type: 'address' },
      { indexed: false, name: 'value', type: 'uint256' },
    ],
  },
] as const

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(),
  },
})

strict

boolean | undefined

• Defaults to false.

index.tsx

import { useWatchContractEvent } from 'wagmi'
import { abi } from './abi'

function App() {
  useWatchContractEvent({
    address: '0x6b175474e89094c44da98b954eedeac495271d0f',
    abi,
    eventName: 'Transfer',
    onLogs(logs) {
      console.log('New logs!', logs)
    },
    strict: true
  })
}

abi.ts

export const abi = [
  {
    type: 'event',
    name: 'Approval',
    inputs: [
      { indexed: true, name: 'owner', type: 'address' },
      { indexed: true, name: 'spender', type: 'address' },
      { indexed: false, name: 'value', type: 'uint256' },
    ],
  },
  {
    type: 'event',
    name: 'Transfer',
    inputs: [
      { indexed: true, name: 'from', type: 'address' },
      { indexed: true, name: 'to', type: 'address' },
      { indexed: false, name: 'value', type: 'uint256' },
    ],
  },
] as const

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(),
  },
})

syncConnectedChain

boolean | undefined

• Set up subscriber for connected chain changes.
• Defaults to Config['syncConnectedChain'].

index.tsx

import { useWatchContractEvent } from 'wagmi'
import { abi } from './abi'

function App() {
  useWatchContractEvent({
    address: '0x6b175474e89094c44da98b954eedeac495271d0f',
    abi,
    eventName: 'Transfer',
    onLogs(logs) {
      console.log('New logs!', logs)
    },
    syncConnectedChain: true
  })
}

abi.ts

export const abi = [
  {
    type: 'event',
    name: 'Approval',
    inputs: [
      { indexed: true, name: 'owner', type: 'address' },
      { indexed: true, name: 'spender', type: 'address' },
      { indexed: false, name: 'value', type: 'uint256' },
    ],
  },
  {
    type: 'event',
    name: 'Transfer',
    inputs: [
      { indexed: true, name: 'from', type: 'address' },
      { indexed: true, name: 'to', type: 'address' },
      { indexed: false, name: 'value', type: 'uint256' },
    ],
  },
] as const

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 UseWatchContractEventReturnType } from 'wagmi'

Hook returns void

Action

• watchContractEvent