On this page

eth_call

Executes a new message call immediately without creating a transaction on the blockchain. This is used for reading data from smart contracts.

Parameters

Index	Type	Description
0	`object`	Transaction call object
1	`string`	Block number or tag (`latest`, `earliest`, `pending`)

Transaction Call Object

Field	Type	Required	Description
`to`	`string`	Yes	Contract address
`data`	`string`	No	Encoded function call data
`from`	`string`	No	Sender address (for context)
`gas`	`string`	No	Gas limit (hex)
`gasPrice`	`string`	No	Gas price (hex)
`value`	`string`	No	Value in wei (hex)

Returns

string - The return data of the call (hex encoded)

Example

Read ERC-20 Balance


// balanceOf(address) selector: 0x70a08231
const address = '0xYourAddress...'.slice(2).padStart(64, '0')
const data = '0x70a08231' + address
 
const balance = await window.$onekey.ethereum.request({
  method: 'eth_call',
  params: [{
    to: '0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48', // USDC
    data: data
  }, 'latest']
})
 
console.log('Balance:', BigInt(balance).toString())

Read Contract Name


// name() selector: 0x06fdde03
const name = await window.$onekey.ethereum.request({
  method: 'eth_call',
  params: [{
    to: '0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48',
    data: '0x06fdde03'
  }, 'latest']
})
 
// Decode the result (ABI encoded string)
// Decode `name` with your ABI library's string decoder.
console.log('ABI-encoded contract name:', name)

Using ethers.js


import { Contract, BrowserProvider } from 'ethers'
 
const provider = new BrowserProvider(window.$onekey.ethereum)
 
const contract = new Contract(
  '0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48',
  ['function balanceOf(address) view returns (uint256)'],
  provider
)
 
const balance = await contract.balanceOf('0xYourAddress...')
console.log('USDC Balance:', balance.toString())

Errors

Code	Message	Description
-32000	Execution reverted	Contract call reverted
-32602	Invalid params	Invalid call parameters

Notes

This method does not consume gas or modify state
The from address is optional but may affect the result for some contracts
Choose a block tag appropriate for your use case; latest reflects the latest block visible to the endpoint
For complex contract interactions, consider using ethers.js or web3.js

The token-address examples are for Ethereum mainnet. Confirm the chain and substitute a complete 20-byte account address before encoding balanceOf.