getBlocks

Learn getBlocks use cases, code examples, request parameters, response structure, and tips.

The getBlocks RPC method returns a list of confirmed block slot numbers between a specified start_slot and an optional end_slot. It’s useful when you need to know which blocks were confirmed within a certain range—without fetching full block contents.

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✅ Common Use Cases

• Identify Confirmed Blocks in a Range Quickly fetch all block slots that were successfully confirmed between two slots.

• Iterate Over Confirmed Slots Use the list of confirmed slots to loop through and fetch detailed block data later via getBlock.

• Audit Block Presence Verify whether blocks exist across a specific slot range for basic validation or reporting.

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🛠 Request Parameters

getBlocks accepts the following parameters:

• start_slot (u64, required): The first slot of the range (inclusive).

• end_slot (u64, optional): The last slot of the range (inclusive). If omitted, the method will return confirmed blocks up to the latest available slot. ⚠️ The range between start_slot and end_slot must not exceed 500,000 slots.

• commitment (string, optional): Commitment level passed as a field in a config object. If omitted, the node's default is used. Typical values:

  • processed

  • confirmed

  • finalized

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📦 Response Structure

The result field will be an array of slot numbers (as unsigned 64-bit integers), each representing a confirmed block.

[355104000, 355104001, 355104002, 355104003, 355104004]

This means blocks were confirmed at these slots—note that some slots may be skipped (e.g., 355104004).

💡 Examples

1. Get Confirmed Blocks in a Slot Range

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "getBlocks",
  "params": [355104000, 355104001]
}

1. Get Blocks from Start Slot to Latest Confirmed Slot

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "getBlocks",
  "params": [355104000]
}

1. Get Blocks Using a Specific Commitment Level

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "getBlocks",
  "params": [355104000, 355104001, { "commitment": "confirmed" }]
}

Code Examples

Nodejs

const fetch = require('node-fetch');

async function getBlocks(rpcUrl) {
  try {
    const response = await fetch(rpcUrl, {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json',
      },
      body: JSON.stringify({
        jsonrpc: '2.0',
        id: 1,
        method: 'getBlocks',
        "params": [
            355104000,
            355104001,
            { "commitment": "confirmed" }
          ]
      }),
    });

    const data = await response.json();
    
    // Print the exact full response
    console.log('Full RPC Response:');
    console.log(JSON.stringify(data, null, 2));
    
    return data;
  } catch (error) {
    console.error('Error getting health:', error.message);
    return null;
  }
}

// Example usage
const RPC_URL = 'https://rpc.coinvera.io/?x-api-key=your-coinvera-x-api-key';

getBlocks(RPC_URL);

Python

Example Response

{
  "jsonrpc": "2.0",
  "result": [
    355104000,
    355104001
  ],
  "id": 1
}

🧠 Developer Tips

• Range Limit Enforcement The maximum allowed range is 500,000 slots. Splitting larger ranges into chunks is required for historical scans.

• Ledger Retention Differences Very old slot data may not be available on all RPC nodes. Empty arrays or errors might be returned for out-of-retention queries.

• Consistency with Commitment Block confirmation status can vary depending on the commitment level and the specific RPC node queried—especially for recent slots.

• Use as a Prefilter for getBlock getBlocks is often used to determine which blocks exist before making multiple calls to getBlock for deeper inspection.

• Effective Pagination Strategy For scanning long history segments, implement pagination by dividing your range into multiple sub-ranges of 500,000 slots or fewer.