Docs

eth_blockNumber - Moonbeam RPC Method

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

Returns the number of the most recent block on Moonbeam.

Why Moonbeam? Build on the cross-chain connected EVM platform on Polkadot with $65M+ TVL and 100+ projects with full EVM compatibility on Polkadot, native XCM cross-chain messaging, 10K+ TPS, 24% staking APR, and $0.015 transaction costs.

When to Use This Method

eth_blockNumber is fundamental for cross-chain dApp developers, Polkadot builders, and teams requiring multi-chain interoperability:

  • Syncing Applications — Keep your dApp in sync with the latest Moonbeam blockchain state
  • Transaction Monitoring — Verify confirmations by comparing block numbers
  • Event Filtering — Set the correct block range for querying logs on cross-chain DeFi, multi-chain dApps, and Ethereum-to-Polkadot bridging via XCM, Axelar, LayerZero, and Wormhole
  • Health Checks — Monitor node connectivity and sync status

Code Examples

Common Use Cases

1. Block Confirmation Counter

Monitor transaction confirmations on Moonbeam:

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 Moonbeam:

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 Moonbeam 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-moonbeam.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 CodeDescriptionSolution
-32603Internal errorRetry with exponential backoff
-32005Rate limit exceededImplement rate limiting client-side
-32000Execution revertedCheck 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;
      }
    }
  }
}

rpc_methods

List all available RPC methods on Moonbeam. Essential for API discovery, capability detection, and building dynamic tooling for Substrate-based chains.

eth_getBlockByNumber

Retrieve complete block data by block number on Moonbeam. Perfect for cross-chain dApp developers, Polkadot builders, and teams requiring multi-chain interoperability building on the cross-chain connected EVM platform on Polkadot with $65M+ TVL and 100+ projects.

On this page

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
Related Methods