eth_call - Base

Example code for the eth_call JSON-RPC method. Complete guide on how to use eth_call JSON-RPC in GetBlock Web3 documentation.

This method executes a new message call immediately without creating a transaction on the blockchain. This is the primary method for reading data from smart contracts, including token balances, contract state, and view/pure function results.

Parameters

Parameter	Type	Required	Description
transaction	object	Yes	Transaction call object
blockParameter	string	Yes	Block number in hex, or "latest", "earliest", "pending"

Transaction Object

Field	Type	Required	Description
from	string	No	20-byte sender address
to	string	Yes	20-byte recipient/contract address
gas	string	No	Gas limit for the call (hex)
gasPrice	string	No	Gas price in wei (hex)
value	string	No	Value to send in wei (hex)
data	string	No	Encoded function call data

Request

cURL

curl --location --request POST 'https://go.getblock.io/<ACCESS-TOKEN>/' \
--header 'Content-Type: application/json' \
--data-raw '{
    "jsonrpc": "2.0",
    "method": "eth_call",
    "params": [{
        "to": "0x4200000000000000000000000000000000000006",
        "data": "0x70a082310000000000000000000000006E0d01A76C3Cf4288372a29124A26D4353EE51BE"
    }, "latest"],
    "id": "getblock.io"
}'

Axios

Request

Rust

Response

{
    "jsonrpc": "2.0",
    "id": "getblock.io",
    "result": "0x0000000000000000000000000000000000000000000000000de0b6b3a7640000"
}

Response Parameters

Parameter	Type	Description
jsonrpc	string	JSON-RPC protocol version ("2.0")
id	string	Request identifier matching the request
result	string	Hex-encoded return data from the contract call

Use Cases

• Token Balances: Query ERC-20 token balances using balanceOf

• Contract State: Read public state variables from smart contracts

• Price Feeds: Query oracle prices from Chainlink or other protocols

• NFT Metadata: Read NFT ownership and metadata

• DeFi Calculations: Query pool reserves, exchange rates, and liquidity

Error Handling

Error Code	Message	Description
-32602	Invalid params	Invalid transaction object or block parameter
-32603	Internal error	Contract execution error
3	Execution reverted	Contract reverted the call
-32000	Execution error	Insufficient gas or other execution failure

Web3 Integration

Ethers.js

ethers-example.js

const { ethers } = require('ethers');

const provider = new ethers.JsonRpcProvider('https://go.getblock.io/<ACCESS-TOKEN>/');

// Using Contract interface for type-safe calls
async function getTokenBalance(tokenAddress, walletAddress) {
    const abi = ['function balanceOf(address) view returns (uint256)'];
    const contract = new ethers.Contract(tokenAddress, abi, provider);
    
    const balance = await contract.balanceOf(walletAddress);
    console.log('Balance:', ethers.formatUnits(balance, 18));
    
    return balance;
}

// WETH on Base
getTokenBalance(
    '0x4200000000000000000000000000000000000006',
    '0x6E0d01A76C3Cf4288372a29124A26D4353EE51BE'
);

// Low-level call
async function rawCall(to, data) {
    const result = await provider.call({
        to: to,
        data: data
    });
    return result;
}

Viem