queryNetwork/blockHeight

Query the current block height of the Cardano blockchain. This returns the absolute block number since genesis.

Request

{
  "jsonrpc": "2.0",
  "method": "queryNetwork/blockHeight"
}

No parameters required.

Response

{
  "jsonrpc": "2.0",
  "method": "queryNetwork/blockHeight",
  "result": 10234567
}

Response Fields

Code Examples

async function getBlockHeight() {
const response = await fetch('https://api.nacho.builders/v1/ogmios', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
    'apikey': process.env.NACHO_API_KEY
  },
  body: JSON.stringify({
    jsonrpc: '2.0',
    method: 'queryNetwork/blockHeight'
  })
});

const { result } = await response.json();
return result;
}

const height = await getBlockHeight();
console.log('Current block height:', height.toLocaleString());

Block Height vs Slot Number

Slots advance every second, but blocks are only produced when a stake pool is selected as leader (~20 seconds average).

async function getBlockInfo() {
  const [height, tip] = await Promise.all([
    getBlockHeight(),
    getLedgerTip()
  ]);

  const slotUtilization = height / tip.slot;
  console.log('Block height:', height);
  console.log('Current slot:', tip.slot);
  console.log('Slot utilization:', (slotUtilization * 100).toFixed(2), '%');
}

Use Cases

• Sync monitoring - Track node synchronization progress
• Block explorers - Display current chain height
• Analytics - Calculate block production statistics
• Health checks - Verify node is receiving new blocks