# eth\_getUncleByBlockNumberAndIndex - Ethereum {% hint style="success" %} This method returns an uncle block specified by the block number and index {% endhint %} The eth\_getUncleByBlockNumberAndIndex method is part of the Ethereum JSON RPC Core API, used to interact with Ethereum nodes. This method returns an uncle block specified by the block number and index. The eth\_getUncleByBlockNumberAndIndex RPC Ethereum method helps developers to retrieve information about uncle blocks, which can be useful for analyzing network performance and consensus behavior. ### Supported Networks The eth\_getUncleByBlockNumberAndIndex RPC Ethereum method supports the following network types: * Mainnet * Testnet: Sepolia, Hoodi ### Parameters * QUANTITY | TAG: The block number, or one of the string tags latest, earliest, or pending. * QUANTITY: The index of the uncle within the block. * value: Placeholder for any additional data. ### Request URL ```json https://go.getblock.io// ``` To make a request, send a JSON object with the jsonrpc, method, and params fields. Below is an example of how to make a request using curl: {% tabs %} {% tab title="curl" %} ```json curl --location --request POST 'https://go.getblock.io//' \ --header 'Content-Type: application/json' \ --data-raw '{ "jsonrpc": "2.0", "method": "eth_getUncleByBlockNumberAndIndex", "params": [ "0x7689D2", "0x0" ], "id": "getblock.io" }' ``` {% endtab %} {% tab title="ws" %} ```json wscat -c wss://go.getblock.io// # wait for connection and send the request body { "jsonrpc": "2.0", "method": "eth_getUncleByBlockNumberAndIndex", "params": [ "0x7689D2", "0x0" ], "id": "getblock.io" } ``` {% endtab %} {% endtabs %} ### Response The server responds with a JSON object containing the uncle block details. Below is an example of a typical response: ```json { "id": "getblock.io", "jsonrpc": "2.0", "result": { "difficulty": "0x77daec467bf93", "extraData": "0x50505945206e616e6f706f6f6c2e6f7267", "gasLimit": "0x7a121d", "gasUsed": "0x7a0f7b", "hash": "0x42d83ae9c0743f4b1f9c61ff7ea8b164c1bab3627decd49233760680be006ecf", "logsBloom": "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", "miner": "0x52bc44d5378309ee2abf1539bf71de1b7d7be3b5", "mixHash": "0xf977fcdb52868be410b75ef2becc35cc312f13ab0a6ce400ecd9d445f66fa3f2", "nonce": "0x628b28403bf1e3d3", "number": "0x7689d0", "parentHash": "0xb32cfdfbf4adb05d30f02fcc6fe039cc6666402142954051c1a1cb9cc91aa11e", "receiptsRoot": "0x9c7c8361d1a24ea2841432234c81974a9920d3eba2b2b1c496b5f925a95cb4ac", "sha3Uncles": "0x7d972aa1b182b7e93f1db043f03fbdbfac6874fe7e67e162141bcc0aefa6336b", "size": "0x21a", "stateRoot": "0x74e97b77813146344d75acb5a52a006cc6dfaca678a10fb8a484a8443e919272", "timestamp": "0x5cdcc0a7", "transactionsRoot": "0x1d21626afddf05e5866de66ca3fcd98f1caf5357eba0cc6ec675606e116a891b", "uncles": [], } } ``` ### Response Description * value: A placeholder for any additional value information that might be associated with the uncle block. * difficulty: The difficulty of the uncle block. * extraData: Any extra data included in the uncle block. * gasLimit: The gas limit of the uncle block. * gasUsed: The gas used by the uncle block. * hash: The hash of the uncle block. * logsBloom: Bloom filter for light clients to quickly retrieve related logs. * miner: The address of the miner that mined the uncle block. * mixHash: A hash used in the mining process. * nonce: The hash that proves the work done by the miner. * number: The block number of the uncle. * parentHash: The hash of the parent block. * receiptsRoot: The root of the receipts trie of the uncle block. * sha3Uncles: The SHA3 hash of the uncles data in the block. * size: The size of the uncle block in bytes. * stateRoot: The root of the state trie. * timestamp: The timestamp of when the uncle was mined. * transactionsRoot: The root of the transaction trie of the uncle block. * uncles: Array of uncle hashes. ### Use Case The eth\_getUncleByBlockNumberAndIndex method is useful for developers who need to analyze the structure of uncle blocks in Ethereum. This method helps to gain insights into the consensus mechanism and understand the process of including uncles in the blockchain. By using the eth\_getUncleByBlockNumberAndIndex RPC Ethereum method, developers can easily access all necessary details about an uncle block. In case of an eth\_getUncleByBlockNumberAndIndex error, developers should verify that the provided block number and index are correct. An eth\_getUncleByBlockNumberAndIndex example can illustrate the correct usage of this method. ### Code Example You can also make requests to the eth\_getUncleByBlockNumberAndIndex method programmatically using Python. Below is an example using the requests library: {% tabs %} {% tab title="Python" %} ```python import requests import json # Define the API URL and access token url = 'https://go.getblock.io//' headers = {'Content-Type': 'application/json'} # Prepare the request data data = { "jsonrpc": "2.0", "method": "eth_getUncleByBlockNumberAndIndex", "params": [ "0x7689D2", "0x0" ], "id": "getblock.io" } # Send the POST request response = requests.post(url, headers=headers, data=json.dumps(data)) # Parse the JSON response response_data = response.json() # Print the result print(json.dumps(response_data, indent=4)) ``` {% endtab %} {% tab title="JavaScript" %} ```javascript const axios = require('axios'); const url = 'https://go.getblock.io//'; const headers = { 'Content-Type': 'application/json' }; const data = { jsonrpc: '2.0', method: 'eth_getUncleByBlockNumberAndIndex', params: [ '0x7689D2', '0x0' ], id: 'getblock.io' }; axios.post(url, data, { headers }) .then(response => { console.log('Response:', response.data); }) .catch(error => { console.error('Error:', error.message); }); ``` {% endtab %} {% endtabs %} This Python script sends a request to the eth\_getUncleByBlockNumberAndIndex method and prints the returned uncle block information. Make sure to replace \ with your actual API token. The eth\_getUncleByBlockNumberAndIndex method can also be used in Web3 libraries for Ethereum, providing an interface to access uncle block data for various use cases, including network analysis and blockchain research. The Web3 eth\_getUncleByBlockNumberAndIndex method is also available in Web3 libraries, allowing developers to interact with uncle block data programmatically. The Ethereum eth\_getUncleByBlockNumberAndIndex method is an important tool for understanding the structure of uncle blocks, making it a valuable feature of the Ethereum JSON RPC API and Core API Endpoints. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.getblock.io/api-reference/ethereum-eth/eth_getunclebyblocknumberandindex-ethereum.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.