useReadContract

Hook for calling a read-only function on a contract, and returning the response.

A read-only function (constant function) on a Solidity contract is denoted by a pure or view keyword. They can only read the state of the contract, and cannot make any changes to it. Since read-only methods do not change the state of the contract, they do not require any gas to be executed, and can be called by any user without the need to pay for gas.

Import

import { useReadContract } from 'wagmi'

Usage

index.tsxabi.tsconfig.ts

tsx

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

function App() {
  const result = useReadContract({
    abi,
    address: '0x6b175474e89094c44da98b954eedeac495271d0f',
    functionName: 'totalSupply',
  })
}

export const abi = [
  {
    type: 'function',
    name: 'balanceOf',
    stateMutability: 'view',
    inputs: [{ name: 'account', type: 'address' }],
    outputs: [{ type: 'uint256' }],
  },
  {
    type: 'function',
    name: 'totalSupply',
    stateMutability: 'view',
    inputs: [],
    outputs: [{ name: 'supply', type: 'uint256' }],
  },
] as const

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 UseReadContractParameters } from 'wagmi'

abi

Abi | undefined

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

index.tsxabi.tsconfig.ts

tsx

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

function App() {
  const result = useReadContract({
    abi,
    address: '0x6b175474e89094c44da98b954eedeac495271d0f',
    functionName: 'totalSupply',
  })
}

export const abi = [
  {
    type: 'function',
    name: 'balanceOf',
    stateMutability: 'view',
    inputs: [{ name: 'account', type: 'address' }],
    outputs: [{ type: 'uint256' }],
  },
  {
    type: 'function',
    name: 'totalSupply',
    stateMutability: 'view',
    inputs: [],
    outputs: [{ name: 'supply', type: 'uint256' }],
  },
] as const

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(),
  },
})

account

Account | undefined

Account to use when calling the contract (msg.sender).

index.tsxabi.tsconfig.ts

tsx

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

function App() {
  const result = useReadContract({
    abi,
    address: '0x6b175474e89094c44da98b954eedeac495271d0f',
    functionName: 'balanceOf',
    args: ['0x6b175474e89094c44da98b954eedeac495271d0f'],
    account: '0xd2135CfB216b74109775236E36d4b433F1DF507B',
  })
}

export const abi = [
  {
    type: 'function',
    name: 'balanceOf',
    stateMutability: 'view',
    inputs: [{ name: 'account', type: 'address' }],
    outputs: [{ type: 'uint256' }],
  },
  {
    type: 'function',
    name: 'totalSupply',
    stateMutability: 'view',
    inputs: [],
    outputs: [{ name: 'supply', type: 'uint256' }],
  },
] as const

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.tsxabi.tsconfig.ts

tsx

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

function App() {
  const result = useReadContract({
    abi,
    address: '0x6b175474e89094c44da98b954eedeac495271d0f',
    functionName: 'totalSupply',
  })
}

export const abi = [
  {
    type: 'function',
    name: 'balanceOf',
    stateMutability: 'view',
    inputs: [{ name: 'account', type: 'address' }],
    outputs: [{ type: 'uint256' }],
  },
  {
    type: 'function',
    name: 'totalSupply',
    stateMutability: 'view',
    inputs: [],
    outputs: [{ name: 'supply', type: 'uint256' }],
  },
] as const

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

readonly unknown[] | undefined

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

index.tsxabi.tsconfig.ts

tsx

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

function App() {
  const result = useReadContract({
    abi,
    address: '0x6b175474e89094c44da98b954eedeac495271d0f',
    functionName: 'balanceOf',
    args: ['0x6b175474e89094c44da98b954eedeac495271d0f'],
  })
}

export const abi = [
  {
    type: 'function',
    name: 'balanceOf',
    stateMutability: 'view',
    inputs: [{ name: 'account', type: 'address' }],
    outputs: [{ type: 'uint256' }],
  },
  {
    type: 'function',
    name: 'totalSupply',
    stateMutability: 'view',
    inputs: [],
    outputs: [{ name: 'supply', type: 'uint256' }],
  },
] as const

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(),
  },
})

blockNumber

bigint | undefined

Block number to call contract at.

index.tsxabi.tsconfig.ts

tsx

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

function App() {
  const result = useReadContract({
    abi,
    address: '0x6b175474e89094c44da98b954eedeac495271d0f',
    functionName: 'totalSupply',
    blockNumber: 17829139n,
  })
}

export const abi = [
  {
    type: 'function',
    name: 'balanceOf',
    stateMutability: 'view',
    inputs: [{ name: 'account', type: 'address' }],
    outputs: [{ type: 'uint256' }],
  },
  {
    type: 'function',
    name: 'totalSupply',
    stateMutability: 'view',
    inputs: [],
    outputs: [{ name: 'supply', type: 'uint256' }],
  },
] as const

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(),
  },
})

blockTag

Block tag to call contract at.

index.tsxabi.tsconfig.ts

tsx

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

function App() {
  const result = useReadContract({
    abi,
    address: '0x6b175474e89094c44da98b954eedeac495271d0f',
    functionName: 'totalSupply',
    blockTag: 'safe',
  })
}

export const abi = [
  {
    type: 'function',
    name: 'balanceOf',
    stateMutability: 'view',
    inputs: [{ name: 'account', type: 'address' }],
    outputs: [{ type: 'uint256' }],
  },
  {
    type: 'function',
    name: 'totalSupply',
    stateMutability: 'view',
    inputs: [],
    outputs: [{ name: 'supply', type: 'uint256' }],
  },
] as const

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.tsxabi.tsconfig.ts

tsx

import { useReadContract } from 'wagmi'
import { mainnet } from 'wagmi/chains'
import { abi } from './abi'

function App() {
  const result = useReadContract({
    abi,
    address: '0x6b175474e89094c44da98b954eedeac495271d0f',
    functionName: 'totalSupply',
    chainId: mainnet.id,
  })
}

export const abi = [
  {
    type: 'function',
    name: 'balanceOf',
    stateMutability: 'view',
    inputs: [{ name: 'account', type: 'address' }],
    outputs: [{ type: 'uint256' }],
  },
  {
    type: 'function',
    name: 'totalSupply',
    stateMutability: 'view',
    inputs: [],
    outputs: [{ name: 'supply', type: 'uint256' }],
  },
] as const

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.tsxabi.tsconfig.ts

tsx

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

function App() {
  const result = useReadContract({
    abi,
    address: '0x6b175474e89094c44da98b954eedeac495271d0f',
    functionName: 'totalSupply',
    config,
  })
}

export const abi = [
  {
    type: 'function',
    name: 'balanceOf',
    stateMutability: 'view',
    inputs: [{ name: 'account', type: 'address' }],
    outputs: [{ type: 'uint256' }],
  },
  {
    type: 'function',
    name: 'totalSupply',
    stateMutability: 'view',
    inputs: [],
    outputs: [{ name: 'supply', type: 'uint256' }],
  },
] as const

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(),
  },
})

functionName

string | undefined

Function to call on the contract.
Inferred from abi.

index.tsxabi.tsconfig.ts

tsx

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

function App() {
  const result = useReadContract({
    abi,
    address: '0x6b175474e89094c44da98b954eedeac495271d0f',
    functionName: 'balanceOf',
    args: ['0x6b175474e89094c44da98b954eedeac495271d0f'],
  })
}

export const abi = [
  {
    type: 'function',
    name: 'balanceOf',
    stateMutability: 'view',
    inputs: [{ name: 'account', type: 'address' }],
    outputs: [{ type: 'uint256' }],
  },
  {
    type: 'function',
    name: 'totalSupply',
    stateMutability: 'view',
    inputs: [],
    outputs: [{ name: 'supply', type: 'uint256' }],
  },
] as const

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(),
  },
})

scopeKey

string | undefined

Scopes the cache to a given context. Hooks that have identical context will share the same cache.

index.tsxabi.tsconfig.ts

tsx

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

function App() {
  const result = useReadContract({
    abi,
    address: '0x6b175474e89094c44da98b954eedeac495271d0f',
    functionName: 'balanceOf',
    args: ['0x6b175474e89094c44da98b954eedeac495271d0f'],
    scopeKey: 'foo',
  })
}

export const abi = [
  {
    type: 'function',
    name: 'balanceOf',
    stateMutability: 'view',
    inputs: [{ name: 'account', type: 'address' }],
    outputs: [{ type: 'uint256' }],
  },
  {
    type: 'function',
    name: 'totalSupply',
    stateMutability: 'view',
    inputs: [],
    outputs: [{ name: 'supply', type: 'uint256' }],
  },
] as const

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(),
  },
})

query

TanStack Query parameters. See the TanStack Query query docs for more info.

Wagmi does not support passing all TanStack Query parameters

TanStack Query parameters, like queryFn and queryKey, are used internally to make Wagmi work and you cannot override them. Check out the source to see what parameters are not supported. All parameters listed below are supported.

enabled

boolean | undefined

Set this to false to disable this query from automatically running.
Can be used for Dependent Queries.

gcTime

number | Infinity | undefined

Defaults to 5 * 60 * 1000 (5 minutes) or Infinity during SSR
The time in milliseconds that unused/inactive cache data remains in memory. When a query's cache becomes unused or inactive, that cache data will be garbage collected after this duration. When different garbage collection times are specified, the longest one will be used.
If set to Infinity, will disable garbage collection

initialData

ReadContractReturnType | (() => ReadContractReturnType) | undefined

If set, this value will be used as the initial data for the query cache (as long as the query hasn't been created or cached yet)
If set to a function, the function will be called once during the shared/root query initialization, and be expected to synchronously return the initialData
Initial data is considered stale by default unless a staleTime has been set.
initialData is persisted to the cache

initialDataUpdatedAt

number | ((() => number | undefined)) | undefined

If set, this value will be used as the time (in milliseconds) of when the initialData itself was last updated.

networkMode

online' | 'always' | 'offlineFirst' | undefined

Defaults to 'online'
see Network Mode for more information.

notifyOnChangeProps

string[] | 'all' | (() => string[] | 'all') | undefined

If set, the component will only re-render if any of the listed properties change.
If set to ['data', 'error'] for example, the component will only re-render when the data or error properties change.
If set to 'all', the component will opt-out of smart tracking and re-render whenever a query is updated.
If set to a function, the function will be executed to compute the list of properties.
By default, access to properties will be tracked, and the component will only re-render when one of the tracked properties change.

placeholderData

ReadContractReturnType | ((previousValue: ReadContractReturnType | undefined; previousQuery: Query | undefined) => ReadContractReturnType) | undefined

If set, this value will be used as the placeholder data for this particular query observer while the query is still in the pending state.
placeholderData is not persisted to the cache
If you provide a function for placeholderData, as a first argument you will receive previously watched query data if available, and the second argument will be the complete previousQuery instance.

queryClient

QueryClient | undefined

Use this to use a custom QueryClient. Otherwise, the one from the nearest context will be used.

refetchInterval

If set to a number, all queries will continuously refetch at this frequency in milliseconds
If set to a function, the function will be executed with the latest data and query to compute a frequency

refetchIntervalInBackground

boolean | undefined

If set to true, queries that are set to continuously refetch with a refetchInterval will continue to refetch while their tab/window is in the background

refetchOnMount

boolean | 'always' | ((query: Query) => boolean | 'always') | undefined

Defaults to true
If set to true, the query will refetch on mount if the data is stale.
If set to false, the query will not refetch on mount.
If set to 'always', the query will always refetch on mount.
If set to a function, the function will be executed with the query to compute the value

refetchOnReconnect

boolean | 'always' | ((query: Query) => boolean | 'always') | undefined

Defaults to true
If set to true, the query will refetch on reconnect if the data is stale.
If set to false, the query will not refetch on reconnect.
If set to 'always', the query will always refetch on reconnect.
If set to a function, the function will be executed with the query to compute the value

refetchOnWindowFocus

boolean | 'always' | ((query: Query) => boolean | 'always') | undefined

Defaults to true
If set to true, the query will refetch on window focus if the data is stale.
If set to false, the query will not refetch on window focus.
If set to 'always', the query will always refetch on window focus.
If set to a function, the function will be executed with the query to compute the value

retry

boolean | number | ((failureCount: number, error: ReadContractErrorType) => boolean) | undefined

If false, failed queries will not retry by default.
If true, failed queries will retry infinitely.
If set to a number, e.g. 3, failed queries will retry until the failed query count meets that number.
Defaults to 3 on the client and 0 on the server

retryDelay

number | ((retryAttempt: number, error: ReadContractErrorType) => number) | undefined

This function receives a retryAttempt integer and the actual Error and returns the delay to apply before the next attempt in milliseconds.
A function like attempt => Math.min(attempt > 1 ? 2 ** attempt * 1000 : 1000, 30 * 1000) applies exponential backoff.
A function like attempt => attempt * 1000 applies linear backoff.

retryOnMount

boolean | undefined

If set to false, the query will not be retried on mount if it contains an error. Defaults to true.

select

((data: ReadContractReturnType) => unknown) | undefined

This option can be used to transform or select a part of the data returned by the query function. It affects the returned data value, but does not affect what gets stored in the query cache.

staleTime

number | Infinity | undefined

Defaults to 0
The time in milliseconds after data is considered stale. This value only applies to the hook it is defined on.
If set to Infinity, the data will never be considered stale

structuralSharing

boolean | (((oldData: ReadContractReturnType | undefined, newData: ReadContractReturnType) => ReadContractReturnType)) | undefined

Defaults to true
If set to false, structural sharing between query results will be disabled.
If set to a function, the old and new data values will be passed through this function, which should combine them into resolved data for the query. This way, you can retain references from the old data to improve performance even when that data contains non-serializable values.

Return Type

import { type UseReadContractReturnType } from 'wagmi'

The return type's data property is inferrable via the combination of abi, functionName, and args. Check out the TypeScript docs for more info.

TanStack Query query docs

data

ReadContractReturnType

The last successfully resolved data for the query.
Defaults to undefined.

dataUpdatedAt

number

The timestamp for when the query most recently returned the status as 'success'.

error

null | ReadContractErrorType

The error object for the query, if an error was thrown.
Defaults to null

errorUpdatedAt

number

The timestamp for when the query most recently returned the status as 'error'.

errorUpdateCount

number

The sum of all errors.

failureCount

number

The failure count for the query.
Incremented every time the query fails.
Reset to 0 when the query succeeds.

failureReason

null | ReadContractErrorType

The failure reason for the query retry.
Reset to null when the query succeeds.

fetchStatus

'fetching' | 'idle' | 'paused'

fetching Is true whenever the queryFn is executing, which includes initial pending as well as background refetches.
paused The query wanted to fetch, but has been paused.
idle The query is not fetching.
See Network Mode for more information.

isError / isPending / isSuccess

boolean

Boolean variables derived from status.

isFetched

boolean

Will be true if the query has been fetched.

isFetchedAfterMount

boolean

Will be true if the query has been fetched after the component mounted.
This property can be used to not show any previously cached data.

isFetching / isPaused

boolean

Boolean variables derived from fetchStatus.

isLoading

boolean

Is true whenever the first fetch for a query is in-flight
Is the same as isFetching && isPending

isLoadingError

boolean

Will be true if the query failed while fetching for the first time.

isPlaceholderData

boolean

Will be true if the data shown is the placeholder data.

isRefetchError

boolean

Will be true if the query failed while refetching.

isRefetching

boolean

Is true whenever a background refetch is in-flight, which does not include initial 'pending'.
Is the same as isFetching && !isPending

isStale

boolean

Will be true if the data in the cache is invalidated or if the data is older than the given staleTime.

refetch

(options: { cancelRefetch?: boolean | undefined; throwOnError?: boolean | undefined }) => Promise<UseQueryResult<ReadContractReturnType, ReadContractErrorType>>

A function to manually refetch the query.
throwOnError
- When set to true, an error will be thrown if the query fails.
- When set to false, an error will be logged if the query fails.
cancelRefetch
- When set to true, a currently running request will be cancelled before a new request is made.
- When set to false, no refetch will be made if there is already a request running.
- Defaults to true

status

'error' | 'pending' | 'success'

pending if there's no cached data and no query attempt was finished yet.
error if the query attempt resulted in an error. The corresponding error property has the error received from the attempted fetch
success if the query has received a response with no errors and is ready to display its data. The corresponding data property on the query is the data received from the successful fetch or if the query's enabled property is set to false and has not been fetched yet data is the first initialData supplied to the query on initialization.

Type Inference

With abi setup correctly, TypeScript will infer the correct types for functionName, args, and the return type. See the Wagmi TypeScript docs for more information.

InlineConst-Asserted

const  = ({
  : [
    {
      : 'function',
      : 'balanceOf',
      : 'view',
      : [{ : 'account', : 'address' }],
      : [{ : 'uint256' }],
    },
    {
      : 'function',
      : 'totalSupply',
      : 'view',
      : [],
      : [{ : 'supply', : 'uint256' }],
    },
  ],
  : '0x6b175474e89094c44da98b954eedeac495271d0f',
  : 'balanceOf',


  : ['0x6b175474e89094c44da98b954eedeac495271d0f'],
})

.

const  = [
  {
    : 'function',
    : 'balanceOf',
    : 'view',
    : [{ : 'account', : 'address' }],
    : [{ : 'uint256' }],
  },
  {
    : 'function',
    : 'totalSupply',
    : 'view',
    : [],
    : [{ : 'supply', : 'uint256' }],
  },
] as 

const  = ({
  ,
  : '0x6b175474e89094c44da98b954eedeac495271d0f',
  : 'balanceOf',


  : ['0x6b175474e89094c44da98b954eedeac495271d0f'],
})

.

TanStack Query

import {
  type ReadContractData,
  type ReadContractOptions,
  type ReadContractQueryFnData,
  type ReadContractQueryKey,
  readContractQueryKey,
  readContractQueryOptions,
} from 'wagmi/query'

Action

readContract

useReadContract ​

Import ​

Usage ​

Parameters ​

abi ​

account ​

address ​

args ​

blockNumber ​

blockTag ​

chainId ​

config ​

functionName ​

scopeKey ​

query ​

enabled ​

gcTime ​

initialData ​

initialDataUpdatedAt ​

meta ​

networkMode ​

notifyOnChangeProps ​

placeholderData ​

queryClient ​

refetchInterval ​

refetchIntervalInBackground ​

refetchOnMount ​

refetchOnReconnect ​

refetchOnWindowFocus ​

retry ​

retryDelay ​

retryOnMount ​

select ​

staleTime ​

structuralSharing ​

Return Type ​

data ​

dataUpdatedAt ​

error ​

errorUpdatedAt ​

errorUpdateCount ​

failureCount ​

failureReason ​

fetchStatus ​

isError / isPending / isSuccess ​

isFetched ​

isFetchedAfterMount ​

isFetching / isPaused ​

isLoading ​

isLoadingError ​

isPlaceholderData ​

isRefetchError ​

isRefetching ​

isStale ​

refetch ​

status ​

Type Inference ​

TanStack Query ​

Action ​

useReadContract

Import

Usage

Parameters

abi

account

address

args

blockNumber

blockTag

chainId

config

functionName

scopeKey

query

enabled

gcTime

initialData

initialDataUpdatedAt

meta

networkMode

notifyOnChangeProps

placeholderData

queryClient

refetchInterval

refetchIntervalInBackground

refetchOnMount

refetchOnReconnect

refetchOnWindowFocus

retry

retryDelay

retryOnMount

select

staleTime

structuralSharing

Return Type

data

dataUpdatedAt

error

errorUpdatedAt

errorUpdateCount

failureCount

failureReason

fetchStatus

isError / isPending / isSuccess

isFetched

isFetchedAfterMount

isFetching / isPaused

isLoading

isLoadingError

isPlaceholderData

isRefetchError

isRefetching

isStale

refetch

status

Type Inference

TanStack Query

Action