> ## Documentation Index
> Fetch the complete documentation index at: https://docs.chainstack.com/llms.txt
> Use this file to discover all available pages before exploring further.

# eth_getUncleCountByBlockNumber | Base

Base API method that retrieves the number of uncles in a block, identified by its number. Uncles are blocks that are not part of the main blockchain but are still valid and have a relationship to a block on the main chain.

This might be useful in the future when there's a decentralized or a shared sequencer.

<Check>
  **Get your own node endpoint today**

  [Start for free](https://console.chainstack.com/) and get your app to production levels immediately. No credit card required.

  You can sign up with your GitHub, X, Google, or Microsoft account.
</Check>

## Parameters

* `blockNumber` — the number of the block for which the uncle count is being queried, encoded as a hexadecimal string.

## Response

* `result` — the number of uncles in the specified block, encoded as a hexadecimal string. This includes all uncles that were referenced by the block at the time it was sealed.

## Use case

The `eth_getUncleCountByBlockNumber` method is important for applications that monitor the health and security of the blockchain, such as network analysis tools or block explorers. It provides insights into the level of competition among miners and the overall inclusiveness of the blockchain towards valid blocks that did not make it to the main chain.


## OpenAPI

````yaml /openapi/base_node_api/eth_getUncleCountByBlockNumber.json POST /2fc1de7f08c0465f6a28e3c355e0cb14
openapi: 3.0.0
info:
  title: eth_getUncleCountByBlockNumber example
  version: 1.0.0
  description: This is an API example for eth_getUncleCountByBlockNumber.
servers:
  - url: https://base-mainnet.core.chainstack.com
security: []
paths:
  /2fc1de7f08c0465f6a28e3c355e0cb14:
    post:
      tags:
        - Ethereum Operations
      summary: eth_getUncleCountByBlockNumber
      operationId: getUncleCountByBlockNumber
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              properties:
                jsonrpc:
                  type: string
                  default: '2.0'
                method:
                  type: string
                  default: eth_getUncleCountByBlockNumber
                id:
                  type: integer
                  default: 1
                params:
                  type: array
                  items:
                    anyOf:
                      - type: string
                        default: '0xbb623d'
                  default:
                    - '0xbb623d'
      responses:
        '200':
          description: The uncle count of the block by number
          content:
            application/json:
              schema:
                type: object
                properties:
                  jsonrpc:
                    type: string
                  id:
                    type: integer
                  result:
                    type: string

````