eth_blockNumber | zkSync Era RPC Docs

Get the current block height on zkSync Era. Essential for syncing dApps, monitoring transaction confirmations, and blockchain state tracking.

Returns the number of the most recent block on zkSync Era.

Why zkSync? Build on Matter Labs' flagship zkEVM powering the Elastic Network of interoperable hyperchains with ZK Stack modular framework, hyperchain interoperability, native account abstraction, and $1.9B in tokenized real-world assets.

When to Use This Method

eth_blockNumber is fundamental for ZK developers, RWA tokenization teams, and builders launching custom L2/L3 chains:

Syncing Applications — Keep your dApp in sync with the latest zkSync blockchain state
Transaction Monitoring — Verify confirmations by comparing block numbers
Event Filtering — Set the correct block range for querying logs on RWA tokenization ($1.9B, 25% market share), hyperchain deployment via ZK Stack, and cross-chain DeFi
Health Checks — Monitor node connectivity and sync status

Request Parameters

Request

This method accepts no parameters.

Response Body

Response

resultQUANTITY

Hexadecimal string representing the current block number

Error Responses

Errors

Error Response-32603

{  "jsonrpc": "2.0",  "method": "eth_blockNumber",  "params": [],  "id": 1}

{  "jsonrpc": "2.0",  "id": 1,  "result": "0x5BAD55"}

{  "jsonrpc": "2.0",  "id": 1,  "error": {    "code": -32603,    "message": "Internal error"  }}

Code Examples

Bash

curl -X POST https://api-zksync-era-mainnet-full.n.dwellir.com/YOUR_API_KEY \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "eth_blockNumber",
    "params": [],
    "id": 1
  }'

JavaScript

// Using fetch
const response = await fetch('https://api-zksync-era-mainnet-full.n.dwellir.com/YOUR_API_KEY', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({
    jsonrpc: '2.0',
    method: 'eth_blockNumber',
    params: [],
    id: 1
  })
});

const { result } = await response.json();
const blockNumber = parseInt(result, 16);
console.log('zkSync block:', blockNumber);

// Using ethers.js
import { JsonRpcProvider } from 'ethers';

const provider = new JsonRpcProvider('https://api-zksync-era-mainnet-full.n.dwellir.com/YOUR_API_KEY');
const blockNumber = await provider.getBlockNumber();
console.log('zkSync block:', blockNumber);

Python

import requests

def get_block_number():
    response = requests.post(
        'https://api-zksync-era-mainnet-full.n.dwellir.com/YOUR_API_KEY',
        json={
            'jsonrpc': '2.0',
            'method': 'eth_blockNumber',
            'params': [],
            'id': 1
        }
    )
    result = response.json()['result']
    return int(result, 16)

block_number = get_block_number()
print(f'zkSync block: {block_number}')

# Using web3.py
from web3 import Web3

w3 = Web3(Web3.HTTPProvider('https://api-zksync-era-mainnet-full.n.dwellir.com/YOUR_API_KEY'))
print(f'zkSync block: {w3.eth.block_number}')

package main

import (
    "context"
    "fmt"
    "log"

    "github.com/ethereum/go-ethereum/ethclient"
)

func main() {
    client, err := ethclient.Dial("https://api-zksync-era-mainnet-full.n.dwellir.com/YOUR_API_KEY")
    if err != nil {
        log.Fatal(err)
    }

    blockNumber, err := client.BlockNumber(context.Background())
    if err != nil {
        log.Fatal(err)
    }

    fmt.Printf("zkSync block: %d\n", blockNumber)
}

Common Use Cases

1. Block Confirmation Counter

Monitor transaction confirmations on zkSync:

JavaScript

async function getConfirmations(provider, txHash) {
  const tx = await provider.getTransaction(txHash);
  if (!tx || !tx.blockNumber) return 0;

  const currentBlock = await provider.getBlockNumber();
  return currentBlock - tx.blockNumber + 1;
}

// Wait for specific confirmations
async function waitForConfirmations(provider, txHash, confirmations = 6) {
  let currentConfirmations = 0;

  while (currentConfirmations < confirmations) {
    currentConfirmations = await getConfirmations(provider, txHash);
    console.log(`Confirmations: ${currentConfirmations}/${confirmations}`);
    await new Promise(r => setTimeout(r, 2000));
  }

  return true;
}

2. Event Log Filtering

Query events from recent blocks on zkSync:

JavaScript

async function getRecentEvents(provider, contract, eventName, blockRange = 100) {
  const currentBlock = await provider.getBlockNumber();
  const fromBlock = currentBlock - blockRange;

  const filter = contract.filters[eventName]();
  const events = await contract.queryFilter(filter, fromBlock, currentBlock);

  return events;
}

3. Node Health Monitoring

Check if your zkSync node is synced:

JavaScript

async function checkNodeHealth(provider) {
  try {
    const blockNumber = await provider.getBlockNumber();
    const block = await provider.getBlock(blockNumber);

    const now = Date.now() / 1000;
    const blockAge = now - block.timestamp;

    if (blockAge > 60) {
      console.warn(`Node may be behind. Last block was ${blockAge}s ago`);
      return false;
    }

    console.log(`Node healthy. Latest block: ${blockNumber}`);
    return true;
  } catch (error) {
    console.error('Node unreachable:', error);
    return false;
  }
}

Performance Optimization

Caching Strategy

Cache block numbers to reduce API calls:

JavaScript

class BlockNumberCache {
  constructor(ttl = 2000) {
    this.cache = null;
    this.timestamp = 0;
    this.ttl = ttl;
  }

  async get(provider) {
    const now = Date.now();

    if (this.cache && (now - this.timestamp) < this.ttl) {
      return this.cache;
    }

    this.cache = await provider.getBlockNumber();
    this.timestamp = now;
    return this.cache;
  }

  invalidate() {
    this.cache = null;
    this.timestamp = 0;
  }
}

const blockCache = new BlockNumberCache();

Batch Requests

Combine with other calls for efficiency:

JavaScript

const batch = [
  { jsonrpc: '2.0', method: 'eth_blockNumber', params: [], id: 1 },
  { jsonrpc: '2.0', method: 'eth_gasPrice', params: [], id: 2 },
  { jsonrpc: '2.0', method: 'eth_chainId', params: [], id: 3 }
];

const response = await fetch('https://api-zksync-era-mainnet-full.n.dwellir.com/YOUR_API_KEY', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify(batch)
});

const results = await response.json();

Error Handling

Common errors and solutions:

Error Code	Description	Solution
-32603	Internal error	Retry with exponential backoff
-32005	Rate limit exceeded	Implement rate limiting client-side
-32000	Execution reverted	Check node sync status

JavaScript

async function safeGetBlockNumber(provider, maxRetries = 3) {
  for (let i = 0; i < maxRetries; i++) {
    try {
      return await provider.getBlockNumber();
    } catch (error) {
      if (error.code === -32005) {
        await new Promise(r => setTimeout(r, Math.pow(2, i) * 1000));
      } else if (i === maxRetries - 1) {
        throw error;
      }
    }
  }
}

eth_getBlockByNumber — Get full block details by number
eth_getBlockByHash — Get block details by hash
eth_syncing — Check if node is still syncing

eth_blockNumber - zkSync RPC Method

When to Use This Method

Request Parameters

Response Body

Error Responses

Code Examples

Common Use Cases

1. Block Confirmation Counter

2. Event Log Filtering

3. Node Health Monitoring

Performance Optimization

Caching Strategy

Batch Requests

Error Handling

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