eth_getUncleCountByBlockHash | Optimism

Optimism 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.


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


  • 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.

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