> ## 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_getUncleCountByBlockHash | Base

> Base API method that retrieves the number of uncles in a block, identified by its hash. Base API method that retrieves the number of uncles in a block.

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

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

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## Parameters

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

## Response

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

## Use case

The `eth_getUncleCountByBlockHash` method is useful for applications that analyze blockchain security and decentralization aspects, such as block explorers or network analysis tools. It can help these applications understand the level of block competition and the rate at which uncles are included in the blockchain.


## OpenAPI

````yaml /openapi/base_node_api/eth_getUncleCountByBlockHash.json POST /2fc1de7f08c0465f6a28e3c355e0cb14
openapi: 3.0.0
info:
  title: eth_getUncleCountByBlockHash example
  version: 1.0.0
  description: This is an API example for eth_getUncleCountByBlockHash.
servers:
  - url: https://base-mainnet.core.chainstack.com
security: []
paths:
  /2fc1de7f08c0465f6a28e3c355e0cb14:
    post:
      tags:
        - Ethereum Operations
      summary: eth_getUncleCountByBlockHash
      operationId: getUncleCountByBlockHash
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              properties:
                jsonrpc:
                  type: string
                  default: '2.0'
                method:
                  type: string
                  default: eth_getUncleCountByBlockHash
                id:
                  type: integer
                  default: 1
                params:
                  type: array
                  items:
                    anyOf:
                      - type: string
                        default: >-
                          0x07fcc7d5f86839e12afa756e979de05812b5341f936b850c9409aa0938819b30
                  default:
                    - >-
                      0x07fcc7d5f86839e12afa756e979de05812b5341f936b850c9409aa0938819b30
      responses:
        '200':
          description: The uncle count of the block by hash
          content:
            application/json:
              schema:
                type: object
                properties:
                  jsonrpc:
                    type: string
                  id:
                    type: integer
                  result:
                    type: string

````