Docs

eth_blockNumber - Manta RPC Method

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

Returns the number of the most recent block on Manta Pacific.

Why Manta? Build on the modular ZK L2 with Celestia DA delivering the lowest fees for 200+ dApps with first L2 on Celestia mainnet, ZK-as-a-Service via Universal Circuits, Polygon CDK integration, and modular OP Stack architecture.

When to Use This Method

eth_blockNumber is fundamental for ZK application developers, privacy-focused builders, and teams requiring modular scalability:

  • Syncing Applications — Keep your dApp in sync with the latest Manta blockchain state
  • Transaction Monitoring — Verify confirmations by comparing block numbers
  • Event Filtering — Set the correct block range for querying logs on ZK-enabled DeFi, private identity verification, and modular ZK applications via Universal Circuits
  • Health Checks — Monitor node connectivity and sync status

Code Examples

Common Use Cases

1. Block Confirmation Counter

Monitor transaction confirmations on Manta:

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 Manta:

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 Manta 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-manta-pacific-archive.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;
      }
    }
  }
}