# BlockValidationState The validation state of a block after processing — a (mode, result) pair describing whether the kernel accepted the block and, if not, why. ``` final class BlockValidationState ``` ## Overview Pass to [`processBlockHeader(_:state:)`](/documentation/BitcoinKernel/ChainstateManager/processBlockHeader(_:state:)) as an out-parameter; the kernel populates it with the verdict. Read [`validationMode`](/documentation/BitcoinKernel/BlockValidationState/validationMode) for the high-level status and [`blockValidationResult`](/documentation/BitcoinKernel/BlockValidationState/blockValidationResult) for the granular reason on rejection. Wraps the opaque `btck_BlockValidationState` type; `deinit` calls `btck_block_validation_state_destroy` when the last Swift reference drops.