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:', parseInt(balance, 16))

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)
console.log('Contract name:', decodeString(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
Always use latest for most up-to-date state
For complex contract interactions, consider using ethers.js or web3.js