eth_getUncleByBlockNumberAndIndex - Optimism

Example code for the eth_getUncleByBlockNumberAndIndex json-rpc method. Сomplete guide on how to use eth_getUncleByBlockNumberAndIndex json-rpc in GetBlock.io Web3 documentation.

This method returns uncle block information for a given block number. As with eth_getUncleByBlockHashAndIndex, this typically returns null on Optimism because the network doesn't have traditional uncles.

Parameters

Parameter	Type	Description	Required
blockNumber	QUANTITY|TAG	Block number in hex, or 'latest', 'earliest'.	Yes
uncleIndex	QUANTITY	The uncle's index position in hex.	Yes

Request

cURL

curl --location 'https://shared.us-east-1.getblock.io/<ACCESS_TOKEN>' \
--header 'Content-Type: application/json' \
--data '{
   "jsonrpc": "2.0",
   "method": "eth_getUncleByBlockHashAndIndex",
      "params": ["latest", "0x0"],
    "id": "getblock.io"
}'

Axios

import axios from 'axios'
let data = JSON.stringify({
    "jsonrpc": "2.0",
     "method": "eth_getUncleByBlockHashAndIndex",
    "params": ["latest", "0x0"],
    "id": "getblock.io"
};

let config = {
  method: "post",
  maxBodyLength: Infinity,
  url: "https://shared.us-east-1.getblock.io/<ACCESS_TOKEN>",
  headers: {
    "Content-Type": "application/json",
  },
  data: data,
};

axios
  .request(config)
  .then((response) => {
    console.log(JSON.stringify(response.data));
  })
  .catch((error) => {
    console.log(error);
  });

Request

import requests
import json

url = "https://shared.us-east-1.getblock.io/<ACESS_TOKEN>"

payload = json.dumps({
   "jsonrpc": "2.0",
     "method": "eth_getUncleByBlockHashAndIndex",
    "params": ["latest", "0x0"],
    "id": "getblock.io"
})
headers = {
  'Content-Type': 'application/json'
}

response = requests.request("POST", url, headers=headers, data=payload)

print(response.text)

Rust

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

    let mut headers = reqwest::header::HeaderMap::new();
    headers.insert("Content-Type", "application/json".parse()?);

    let data = r#"{
   "jsonrpc": "2.0",
    "method": "eth_getUncleByBlockHashAndIndex",
    "params": ["latest", "0x0"],
    "id": "getblock.io"
}"#;

    let json: serde_json::Value = serde_json::from_str(&data)?;

    let request = client.request(reqwest::Method::POST, "https://shared.us-east-1.getblock.io/<ACCESS_TOKEN>")
        .headers(headers)
        .json(&json);

    let response = request.send().await?;
    let body = response.text().await?;

    println!("{}", body);

    Ok(())
}

Response

A successful response returns the following:

{
    "jsonrpc": "2.0",
    "id": "getblock.io",
    "result": null
}

Response Parameters

• id: A unique request identifier, matching the id sent in the request body.

• jsonrpc: Specifies the use of JSON-RPC version 2.0.

• result: Uncle block object or null (typically null on Optimism).

Use Case

The eth_getUncleByBlockNumberAndIndex method is commonly used for:

• Ethereum compatibility

• API completeness

Error handling

Status Code	Error Message	Cause
404	Not Found	Missing or invalid ACCESS_TOKEN.
-32602	Invalid argument	Invalid block hash Invalid index