eth_blockNumber | Flow EVM Gateway RPC Docs

Get the current block height on Flow EVM Gateway. Essential for syncing dApps, monitoring transaction confirmations, and blockchain state tracking.

Returns the number of the most recent block on Flow EVM Gateway.

Why Flow EVM? Build on the EVM-equivalent layer on Flow blockchain enabling Cadence+Solidity composability with full EVM equivalence on Flow, atomic multi-operation transactions, 40% lower gas fees, and 473% contract growth in 2025.

When to Use This Method

eth_blockNumber is fundamental for NFT developers, gaming studios, and Solidity devs seeking Cadence interoperability:

Syncing Applications — Keep your dApp in sync with the latest Flow EVM blockchain state
Transaction Monitoring — Verify confirmations by comparing block numbers
Event Filtering — Set the correct block range for querying logs on consumer NFTs (NBA Top Shot, Disney Pinnacle), gaming dApps, and hybrid Cadence-EVM applications
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-flow-evm-gateway-mainnet.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-flow-evm-gateway-mainnet.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('Flow EVM block:', blockNumber);

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

const provider = new JsonRpcProvider('https://api-flow-evm-gateway-mainnet.n.dwellir.com/YOUR_API_KEY');
const blockNumber = await provider.getBlockNumber();
console.log('Flow EVM block:', blockNumber);

Python

import requests

def get_block_number():
    response = requests.post(
        'https://api-flow-evm-gateway-mainnet.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'Flow EVM block: {block_number}')

# Using web3.py
from web3 import Web3

w3 = Web3(Web3.HTTPProvider('https://api-flow-evm-gateway-mainnet.n.dwellir.com/YOUR_API_KEY'))
print(f'Flow EVM 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-flow-evm-gateway-mainnet.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("Flow EVM block: %d\n", blockNumber)
}

Common Use Cases

1. Block Confirmation Counter

Monitor transaction confirmations on Flow EVM:

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 Flow EVM:

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 Flow EVM 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-flow-evm-gateway-mainnet.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 - Flow EVM 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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