I'm interested in the technical question of how you got BIP34Hash and nMinimumChainWork.

The changes were introduced here:

nMinimumChainWork: https://github.com/bitcoin/bitcoin/commit/ad20cddce2097c6561202777fccd257deb1a9810

BIP34Hash and BIP34Height: https://github.com/bitcoin/bitcoin/commit/33c90cf197223fb95f858db80d090d570d70498a

  • You can run the rpc getblockchaininfo to get the current chain work. Consequently this is the minimum chain work, as the chain work can never decrease. Feb 13, 2017 at 14:24

1 Answer 1


The BIP 34 hash is the block hash at which BIP 34 was fully activated and all blocks less than version 2 were rejected as invalid.

nMinimumChainWork is a value that is updated at every release. It is retrieved from the getblockchaininfo RPC of a node that is up at the time of release. nMinimumChainWork is updated at the same time as assumevalid. It is calculated by summing the work done in each block which is calculated by doing 2^256/(target+1)


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