callContract
The callContract function allows for the execution of a read or write function on a contract, and returns the response.
It is similar to readContract, in that it does not require gas to execute and does not change the state of the blockchain, but also supports contract write functions.
It is useful for:
- simulating or validating a contract interaction.
- retrieving return data (and revert reasons) of write functions (via
writeContract).
Internally, callContract uses a Public Client to call the call action with ABI-encoded data.
Import
ts
import { callContract } from 'viem'
Usage
Below is a very basic example of how to call a write function on a contract (with no arguments).
The mint function accepts no arguments, and returns a token ID.
ts
import { callContract } from 'viem'
import { publicClient } from './client'
import { wagmiAbi } from './abi'
const data = await callContract(publicClient, {
address: '0xFBA3912Ca04dd458c843e2EE08967fC04f3579c2',
abi: wagmiAbi,
functionName: 'mint',
})
// 69420
ts
export const wagmiAbi = [
...
{
inputs: [],
name: "mint",
outputs: [{ name: "", type: "uint32" }],
stateMutability: "view",
type: "function",
},
...
] as const;
ts
import { createPublicClient, http } from 'viem'
import { mainnet } from 'viem/chains'
export const publicClient = createPublicClient({
chain: mainnet,
transport: http()
})
Passing Arguments
If your function requires argument(s), you can pass them through with the args attribute.
TypeScript types for args will be inferred from the function name & ABI, to guard you from inserting the wrong values.
For example, the mint function name below requires a tokenId argument, and it is typed as [number].
ts
import { callContract } from 'viem'
import { publicClient } from './client'
import { wagmiAbi } from './abi'
const data = await callContract(publicClient, {
address: '0xFBA3912Ca04dd458c843e2EE08967fC04f3579c2',
abi: wagmiAbi,
functionName: 'mint',
args: [69420]
})
// 69420
ts
export const wagmiAbi = [
...
{
inputs: [{ name: "owner", type: "uint32" }],
name: "mint",
outputs: [{ name: "", type: "uint32" }],
stateMutability: "view",
type: "function",
},
...
] as const;
ts
import { createPublicClient, http } from 'viem'
import { mainnet } from 'viem/chains'
export const publicClient = createPublicClient({
chain: mainnet,
transport: http()
})
Return Value
The response from the contract. Type is inferred.
Parameters
address
- Type:
Address
The contract address.
ts
const data = await callContract(publicClient, {
address: '0xFBA3912Ca04dd458c843e2EE08967fC04f3579c2',
abi: wagmiAbi,
functionName: 'mint',
})
abi
- Type:
Abi
The contract's ABI.
ts
const data = await callContract(publicClient, {
address: '0xFBA3912Ca04dd458c843e2EE08967fC04f3579c2',
abi: wagmiAbi,
functionName: 'mint',
})
functionName
- Type:
string
A function to extract from the ABI.
ts
const data = await callContract(publicClient, {
address: '0xFBA3912Ca04dd458c843e2EE08967fC04f3579c2',
abi: wagmiAbi,
functionName: 'mint',
})
accessList (optional)
- Type:
AccessList
The access list.
ts
const data = await callContract(publicClient, {
address: '0xFBA3912Ca04dd458c843e2EE08967fC04f3579c2',
abi: wagmiAbi,
functionName: 'mint',
args: [69420],
accessList: [{
address: '0xf39fd6e51aad88f6f4ce6ab8827279cfffb92266',
storageKeys: ['0x1'],
}],
})
args (optional)
- Type: Inferred from ABI.
Arguments to pass to function call.
ts
const data = await callContract(publicClient, {
address: '0x1dfe7ca09e99d10835bf73044a23b73fc20623df',
abi: wagmiAbi,
functionName: 'balanceOf',
args: ['0xa5cc3c03994DB5b0d9A5eEdD10CabaB0813678AC']
})
from (optional)
- Type:
Address
Optional sender override.
ts
const data = await callContract(publicClient, {
address: '0xFBA3912Ca04dd458c843e2EE08967fC04f3579c2',
abi: wagmiAbi,
functionName: 'mint',
from: '0xf39fd6e51aad88f6f4ce6ab8827279cfffb92266'
})
gasPrice (optional)
- Type:
bigint
The price (in wei) to pay per gas. Only applies to Legacy Transactions.
ts
const data = await callContract(publicClient, {
address: '0xFBA3912Ca04dd458c843e2EE08967fC04f3579c2',
abi: wagmiAbi,
functionName: 'mint',
args: [69420],
gasPrice: parseGwei('20'),
})
maxFeePerGas (optional)
- Type:
bigint
Total fee per gas (in wei), inclusive of maxPriorityFeePerGas. Only applies to EIP-1559 Transactions
ts
const data = await callContract(publicClient, {
address: '0xFBA3912Ca04dd458c843e2EE08967fC04f3579c2',
abi: wagmiAbi,
functionName: 'mint',
args: [69420],
maxFeePerGas: parseGwei('20'),
})
maxPriorityFeePerGas (optional)
- Type:
bigint
Max priority fee per gas (in wei). Only applies to EIP-1559 Transactions
ts
const data = await callContract(publicClient, {
address: '0xFBA3912Ca04dd458c843e2EE08967fC04f3579c2',
abi: wagmiAbi,
functionName: 'mint',
args: [69420],
maxFeePerGas: parseGwei('20'),
maxPriorityFeePerGas: parseGwei('2'),
})
nonce (optional)
- Type:
number
Unique number identifying this transaction.
ts
const data = await callContract(publicClient, {
address: '0xFBA3912Ca04dd458c843e2EE08967fC04f3579c2',
abi: wagmiAbi,
functionName: 'mint',
args: [69420],
nonce: 69
})
value (optional)
- Type:
number
Value in wei sent with this transaction.
ts
const data = await callContract(publicClient, {
address: '0xFBA3912Ca04dd458c843e2EE08967fC04f3579c2',
abi: wagmiAbi,
functionName: 'mint',
args: [69420],
value: parseEther('1')
})
blockNumber (optional)
- Type:
number
The block number to perform the read against.
ts
const data = await callContract(publicClient, {
address: '0xFBA3912Ca04dd458c843e2EE08967fC04f3579c2',
abi: wagmiAbi,
functionName: 'mint',
blockNumber: 15121123n,
})
blockTag (optional)
- Type:
'latest' | 'earliest' | 'pending' | 'safe' | 'finalized' - Default:
'latest'
The block tag to perform the read against.
ts
const data = await callContract(publicClient, {
address: '0xFBA3912Ca04dd458c843e2EE08967fC04f3579c2',
abi: wagmiAbi,
functionName: 'mint',
blockTag: 'safe',
})