Chain reorganization (reorg)
Last updated:
Applies to: All chains
In more detail
Transactions in the replaced blocks count as included only if the new branch includes them too, and data read from those blocks — logs, receipts, balances — is no longer canonical. Blocks that have reached finality are, by definition, not reorganised.
RPC clients see reorgs as a newHeads subscription delivering two different headers at the same height, and as logs re-emitted with removed set to true in log subscriptions. Keying stored events by block hash rather than block number makes a reorg detectable.