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readContract ​

Action 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 ​

ts
import { readContract } from '@wagmi/core'

Usage ​

ts
import { readContract } from '@wagmi/core'
import { abi } from './abi'
import { config } from './config'

const result = await readContract(config, {
  abi,
  address: '0x6b175474e89094c44da98b954eedeac495271d0f',
  functionName: 'totalSupply',
})
ts
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
ts
import { http, createConfig } from '@wagmi/core'
import { mainnet, sepolia } from '@wagmi/core/chains'

export const config = createConfig({
  chains: [mainnet, sepolia],
  transports: {
    [mainnet.id]: http(),
    [sepolia.id]: http(),
  },
})

Parameters ​

ts
import { type ReadContractParameters } from '@wagmi/core'

abi ​

Abi

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

ts
import { readContract } from '@wagmi/core'
import { abi } from './abi'
import { config } from './config'

const result = await readContract(config, {
  abi, 
  address: '0x6b175474e89094c44da98b954eedeac495271d0f',
  functionName: 'totalSupply',
})
ts
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
ts
import { http, createConfig } from '@wagmi/core'
import { mainnet, sepolia } from '@wagmi/core/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).

ts
import { readContract } from '@wagmi/core'
import { abi } from './abi'
import { config } from './config'

const result = await readContract(config, {
  abi,
  address: '0x6b175474e89094c44da98b954eedeac495271d0f',
  functionName: 'balanceOf',
  args: ['0xd2135CfB216b74109775236E36d4b433F1DF507B'],
  account: '0xd2135CfB216b74109775236E36d4b433F1DF507B', 
})
ts
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
ts
import { http, createConfig } from '@wagmi/core'
import { mainnet, sepolia } from '@wagmi/core/chains'

export const config = createConfig({
  chains: [mainnet, sepolia],
  transports: {
    [mainnet.id]: http(),
    [sepolia.id]: http(),
  },
})

address ​

Address

The contract's address.

ts
import { readContract } from '@wagmi/core'
import { abi } from './abi'
import { config } from './config'

const result = await readContract(config, {
  abi,
  address: '0x6b175474e89094c44da98b954eedeac495271d0f', 
  functionName: 'totalSupply',
})
ts
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
ts
import { http, createConfig } from '@wagmi/core'
import { mainnet, sepolia } from '@wagmi/core/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.
ts
import { readContract } from '@wagmi/core'
import { abi } from './abi'
import { config } from './config'

const result = await readContract(config, {
  abi,
  address: '0x6b175474e89094c44da98b954eedeac495271d0f',
  functionName: 'balanceOf',
  args: ['0xd2135CfB216b74109775236E36d4b433F1DF507B'], 
})
ts
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
ts
import { http, createConfig } from '@wagmi/core'
import { mainnet, sepolia } from '@wagmi/core/chains'

export const config = createConfig({
  chains: [mainnet, sepolia],
  transports: {
    [mainnet.id]: http(),
    [sepolia.id]: http(),
  },
})

blockNumber ​

bigint | undefined

Block number to call contract at.

ts
import { readContract } from '@wagmi/core'
import { abi } from './abi'
import { config } from './config'

const result = await readContract(config, {
  abi,
  address: '0x6b175474e89094c44da98b954eedeac495271d0f',
  functionName: 'totalSupply',
  blockNumber: 17829139n, 
})
ts
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
ts
import { http, createConfig } from '@wagmi/core'
import { mainnet, sepolia } from '@wagmi/core/chains'

export const config = createConfig({
  chains: [mainnet, sepolia],
  transports: {
    [mainnet.id]: http(),
    [sepolia.id]: http(),
  },
})

blockTag ​

'latest' | 'earliest' | 'pending' | 'safe' | 'finalized' | undefined

Block tag to call contract at.

ts
import { readContract } from '@wagmi/core'
import { abi } from './abi'
import { config } from './config'

const result = await readContract(config, {
  abi,
  address: '0x6b175474e89094c44da98b954eedeac495271d0f',
  functionName: 'totalSupply',
  blockTag: 'safe', 
})
ts
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
ts
import { http, createConfig } from '@wagmi/core'
import { mainnet, sepolia } from '@wagmi/core/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.

ts
import { readContract } from '@wagmi/core'
import { mainnet } from 'wagmi/chains'
import { abi } from './abi'
import { config } from './config'

const result = await readContract(config, {
  abi,
  address: '0x6b175474e89094c44da98b954eedeac495271d0f',
  functionName: 'totalSupply',
  chainId: mainnet.id, 
})
ts
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
ts
import { http, createConfig } from '@wagmi/core'
import { mainnet, sepolia } from '@wagmi/core/chains'

export const config = createConfig({
  chains: [mainnet, sepolia],
  transports: {
    [mainnet.id]: http(),
    [sepolia.id]: http(),
  },
})

functionName ​

string

  • Function to call on the contract.
  • Inferred from abi.
ts
import { readContract } from '@wagmi/core'
import { abi } from './abi'
import { config } from './config'

const result = await readContract(config, {
  abi,
  address: '0x6b175474e89094c44da98b954eedeac495271d0f',
  functionName: 'balanceOf', 
  args: ['0xd2135CfB216b74109775236E36d4b433F1DF507B'],
})
ts
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
ts
import { http, createConfig } from '@wagmi/core'
import { mainnet, sepolia } from '@wagmi/core/chains'

export const config = createConfig({
  chains: [mainnet, sepolia],
  transports: {
    [mainnet.id]: http(),
    [sepolia.id]: http(),
  },
})

Return Type ​

ts
import { type ReadContractReturnType } from '@wagmi/core'

unknown

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.

Error ​

ts
import { type ReadContractErrorType } from '@wagmi/core'

TanStack Query ​

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

Viem ​

Released under the MIT License.

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