eth_blockNumber | IoTeX RPC Docs

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

Returns the number of the most recent block on IoTeX.

Why IoTeX? Build on the leading DePIN infrastructure blockchain powering 130+ applications in the $27B+ DePIN ecosystem with W3bstream offchain compute, Quicksilver AI data verification, Vodafone partnership for 5M+ cell tower integration, and ioID device identity.

When to Use This Method

eth_blockNumber is fundamental for DePIN builders, IoT device manufacturers, and real-world AI application developers:

Syncing Applications — Keep your dApp in sync with the latest IoTeX blockchain state
Transaction Monitoring — Verify confirmations by comparing block numbers
Event Filtering — Set the correct block range for querying logs on decentralized physical infrastructure (DePIN), IoT device identity (ioID), and AI-verified real-world data
Health Checks — Monitor node connectivity and sync status

Code Examples

Common Use Cases

1. Block Confirmation Counter

Monitor transaction confirmations on IoTeX:

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 IoTeX:

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 IoTeX 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-iotex-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 - IoTeX RPC Method

When to Use This Method

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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