getBlocks - Solana

Example code for the getBlocks JSON-RPC method. Complete guide on how to use getBlocks JSON-RPC in GetBlock Web3 documentation.

This method returns the confirmed block slots in an inclusive slot range. The range is capped at 500,000 slots per request.

Parameters

Parameter	Type	Required	Description
startSlot	number	Yes	First slot of the range, inclusive
endSlot	number	No	Last slot of the range, inclusive. Must be no more than 500,000 slots after startSlot
config	object	No	Configuration object controlling commitment

Config Object

Field	Type	Required	Description
commitment	string	No	Commitment level: confirmed or finalized. The processed level is not supported

Request

cURL

curl --location --request POST 'https://go.getblock.io/<ACCESS-TOKEN>/' \
--header 'Content-Type: application/json' \
--data-raw '{
    "jsonrpc": "2.0",
    "method": "getBlocks",
    "params": [397234556, 397234561],
    "id": "getblock.io"
}'

@solana/web3.js

example.js

const { Connection } = require('@solana/web3.js');

const connection = new Connection('https://go.getblock.io/<ACCESS-TOKEN>/', 'confirmed');

const blocks = await connection.getBlocks(397234556, 397234561);

console.log(blocks);

Request

example.py

import requests

response = requests.post(
    'https://go.getblock.io/<ACCESS-TOKEN>/',
    headers={'Content-Type': 'application/json'},
    json={
        'jsonrpc': '2.0',
        'method': 'getBlocks',
        'params': [397234556, 397234561],
        'id': 'getblock.io'
    }
)

print(response.json()['result'])

Rust

example.rs

use reqwest::Client;
use serde_json::{json, Value};

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let client = Client::new();

    let response = client
        .post("https://go.getblock.io/<ACCESS-TOKEN>/")
        .header("Content-Type", "application/json")
        .json(&json!({
            "jsonrpc": "2.0",
            "method": "getBlocks",
            "params": [397234556, 397234561],
            "id": "getblock.io"
        }))
        .send()
        .await?
        .json::<Value>()
        .await?;

    println!("Result: {}", response["result"]);
    Ok(())
}

Response

{
    "jsonrpc": "2.0",
    "id": "getblock.io",
    "result": [
        397234556,
        397234557,
        397234558,
        397234560,
        397234561
    ]
}

Response Parameters

Parameter	Type	Description
jsonrpc	string	JSON-RPC protocol version ("2.0")
id	string	Request identifier matching the request
result	array	Array of confirmed block slots in the requested range

Use Cases

• Gap Detection: Compare the returned slots against the range to find skipped slots

• Indexer Scheduling: Enumerate slots to fetch before calling getBlock on each

• Backfill Jobs: Chunk historical ranges into 500,000-slot windows

• Liveness Checks: Measure how many slots in a window produced blocks

Error Handling

Error Code	Message	Description
-32007	Slot was skipped, or missing due to ledger jump to recent snapshot	The slot was skipped by the leader or predates the node's snapshot
-32009	Slot was skipped, or missing in long-term storage	The slot is absent from the node's long-term ledger storage
-32602	Invalid params	Range exceeds 500,000 slots or endSlot precedes startSlot
-32603	Internal error	Node failed to read the blockstore for the range