eth_call

How to use it

// yarn add @tatumio/tatum

import { TatumSDK, BinanceSmartChain, Network } from '@tatumio/tatum'

const tatum = await TatumSDK.init<BinanceSmartChain>({ network: Network.BINANCE_SMART_CHAIN })

const result = await tatum.rpc.call(
  {
    to: '0x8AC76a51cc950d9822D68b83fE1Ad97B32Cd580d', // Replace with the ERC-20 token contract address
    data: '0x70a082310000000000000000000000008894E0a0c962CB723c1976a4421c95949bE2D4E3', // The function signature for balanceOf(address), followed by the address tokens
  },
  'latest',
)

await tatum.destroy() // Destroy Tatum SDK - needed for stopping background jobs

Overview

Executes a new message call immediately without creating a transaction on the block chain. Often used for executing read-only smart contract functions, for example the balanceOf for an ERC-20 contract.

Top 5 most commonly used use cases for eth_call:

1. Retrieve Token Balance: Check an ERC-20 token balance for an address.
2. Query Contract State: Get contract data, like a game score or auction status.
3. Validate Inputs: Pre-validate function inputs before sending a transaction.
4. Price Oracles: Fetch real-time price data for decentralized applications.
5. Gas Estimation: Estimate gas costs for future transactions.

Parameters

1. Object - The transaction call object

• from: DATA, 20 Bytes - (optional) The address the transaction is sent from.
• to: DATA, 20 Bytes - The address the transaction is directed to.
• gas: QUANTITY - (optional) Integer of the gas provided for the transaction execution. eth_call consumes zero gas, but this parameter may be needed by some executions.
• gasPrice: QUANTITY - (optional) Integer of the gasPrice used for each paid gas
• value: QUANTITY - (optional) Integer of the value sent with this transaction
• data: DATA - (optional) Hash of the method signature and encoded parameters. For details see Ethereum Contract ABI in the Solidity documentation(opens in a new tab)

2. QUANTITY|TAG - integer block number, or the string "latest", "earliest" or "pending"

Return Object

DATA - the return value of executed contract.

JSON Examples

Request

{
  "jsonrpc": "2.0",
  "method": "eth_call",
  "params": [
    {
      "to": "0x8AC76a51cc950d9822D68b83fE1Ad97B32Cd580d", // Replace with the ERC-20 token contract address in this case USDC on Binance Smart Chain
      "data": "0x70a082310000000000000000000000008894E0a0c962CB723c1976a4421c95949bE2D4E3" // The function signature for balanceOf(address), followed by the address to query in this case holder of USDC tokens
    },
    "latest"
  ],
  "id": 1
}

Response

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": "0x0000000000000000000000000000000000000000002f798bddfae24274770b92"
}