eth_getLogs - Base

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

The eth_getLogs method returns an array of all logs matching a given filter object. This is the primary method for querying event logs from smart contracts, essential for tracking token transfers, DEX swaps, and other on-chain events.

Parameters

Parameter

Type

Required

Description

filterObject

object

Yes

Filter options object

Filter Object

Field

Type

Required

Description

fromBlock

string

Start block number (hex) or "latest", "earliest"

toBlock

string

End block number (hex) or "latest", "earliest"

address

string/array

Contract address or array of addresses

topics

array

Array of topic filters (up to 4 topics)

blockHash

string

Specific block hash (alternative to fromBlock/toBlock)

Request

curl --location --request POST 'https://go.getblock.io/<ACCESS-TOKEN>/' \
--header 'Content-Type: application/json' \
--data-raw '{
    "jsonrpc": "2.0",
    "method": "eth_getLogs",
    "params": [{
        "fromBlock": "0x12d6800",
        "toBlock": "0x12d6900",
        "address": "0x4200000000000000000000000000000000000006",
        "topics": ["0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef"]
    }],
    "id": "getblock.io"
}'

const axios = require('axios');

// Query ERC-20 Transfer events
const transferTopic = '0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef';

const response = await axios.post('https://go.getblock.io/<ACCESS-TOKEN>/', {
    jsonrpc: '2.0',
    method: 'eth_getLogs',
    params: [{
        fromBlock: '0x12d6800',
        toBlock: '0x12d6900',
        address: '0x4200000000000000000000000000000000000006', // WETH
        topics: [transferTopic]
    }],
    id: 'getblock.io'
}, {
    headers: { 'Content-Type': 'application/json' }
});

const logs = response.data.result;
console.log('Found', logs.length, 'transfer events');
logs.forEach(log => {
    console.log('Block:', parseInt(log.blockNumber, 16));
    console.log('Tx:', log.transactionHash);
});

import requests

# ERC-20 Transfer event signature
transfer_topic = '0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef'

response = requests.post(
    'https://go.getblock.io/<ACCESS-TOKEN>/',
    headers={'Content-Type': 'application/json'},
    json={
        'jsonrpc': '2.0',
        'method': 'eth_getLogs',
        'params': [{
            'fromBlock': '0x12d6800',
            'toBlock': '0x12d6900',
            'address': '0x4200000000000000000000000000000000000006',
            'topics': [transfer_topic]
        }],
        'id': 'getblock.io'
    }
)

result = response.json()
logs = result['result']
print(f'Found {len(logs)} transfer events')
for log in logs:
    print(f'Block: {int(log["blockNumber"], 16)}')

use reqwest::Client;
use serde_json::{json, Value};

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let client = Client::new();
    
    let response = client
        .post("https://go.getblock.io/<ACCESS-TOKEN>/")
        .header("Content-Type", "application/json")
        .json(&json!({
            "jsonrpc": "2.0",
            "method": "eth_getLogs",
            "params": [{
                "fromBlock": "0x12d6800",
                "toBlock": "0x12d6900",
                "address": "0x4200000000000000000000000000000000000006",
                "topics": ["0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef"]
            }],
            "id": "getblock.io"
        }))
        .send()
        .await?
        .json::<Value>()
        .await?;
    
    let logs = response["result"].as_array().unwrap();
    println!("Found {} logs", logs.len());
    Ok(())
}

Response

{
    "jsonrpc": "2.0",
    "id": "getblock.io",
    "result": [
        {
            "address": "0x4200000000000000000000000000000000000006",
            "topics": [
                "0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef",
                "0x000000000000000000000000sender_address_padded",
                "0x000000000000000000000000recipient_address_padded"
            ],
            "data": "0x0000000000000000000000000000000000000000000000000de0b6b3a7640000",
            "blockNumber": "0x12d6850",
            "transactionHash": "0x...",
            "transactionIndex": "0x0",
            "blockHash": "0x...",
            "logIndex": "0x0",
            "removed": false
        }
    ]
}

Response Parameters

Parameter

Type

Description

address

string

Contract address that emitted the log

topics

array

Indexed event parameters (up to 4)

data

string

Non-indexed event data (hex)

blockNumber

string

Block number in hex

transactionHash

string

Transaction hash

transactionIndex

string

Transaction index in block (hex)

blockHash

string

Block hash

logIndex

string

Log index in block (hex)

removed

boolean

True if log was removed due to chain reorg

Use Cases

Token Transfer Tracking: Monitor ERC-20/ERC-721 transfers
DEX Event Processing: Track swaps, liquidity events
Contract Event Indexing: Build event-driven databases
Real-time Notifications: Alert on specific events
Historical Analysis: Analyze past contract activity

Error Handling

Error Code

Message

Description

-32602

Invalid params

Invalid filter object

-32603

Internal error

Query range too large or node failure

-32005

Query returned more than limit

Too many logs in response

Web3 Integration

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

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

async function getLogs() {
    // Using filter
    const filter = {
        address: '0x4200000000000000000000000000000000000006', // WETH
        topics: [
            ethers.id('Transfer(address,address,uint256)')
        ],
        fromBlock: 'latest',
        toBlock: 'latest'
    };
    
    const logs = await provider.getLogs(filter);
    
    logs.forEach(log => {
        console.log('Block:', log.blockNumber);
        console.log('Tx:', log.transactionHash);
        console.log('Data:', log.data);
    });
    
    return logs;
}

// Using Contract interface for parsed events
async function getTransferEvents() {
    const abi = ['event Transfer(address indexed from, address indexed to, uint256 value)'];
    const contract = new ethers.Contract(
        '0x4200000000000000000000000000000000000006',
        abi,
        provider
    );
    
    const filter = contract.filters.Transfer();
    const events = await contract.queryFilter(filter, -100, 'latest');
    
    events.forEach(event => {
        console.log('From:', event.args.from);
        console.log('To:', event.args.to);
        console.log('Value:', ethers.formatEther(event.args.value));
    });
    
    return events;
}

getLogs();

import { createPublicClient, http, parseAbiItem } from 'viem';
import { base } from 'viem/chains';

const client = createPublicClient({
    chain: base,
    transport: http('https://go.getblock.io/<ACCESS-TOKEN>/')
});

async function getLogs() {
    const logs = await client.getLogs({
        address: '0x4200000000000000000000000000000000000006',
        event: parseAbiItem('event Transfer(address indexed from, address indexed to, uint256 value)'),
        fromBlock: BigInt(19800000),
        toBlock: 'latest'
    });
    
    logs.forEach(log => {
        console.log('From:', log.args.from);
        console.log('To:', log.args.to);
        console.log('Value:', log.args.value);
    });
    
    return logs;
}

// Watch for new logs
async function watchLogs() {
    const unwatch = client.watchEvent({
        address: '0x4200000000000000000000000000000000000006',
        event: parseAbiItem('event Transfer(address indexed from, address indexed to, uint256 value)'),
        onLogs: logs => {
            logs.forEach(log => {
                console.log('New Transfer:', log.args);
            });
        }
    });
    
    return unwatch;
}

getLogs();

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