Bitcoin Transactions Quick refs : sighash.md, serialization.md, malleability.md, rbf-cpfp.md, v3-truc.md Anatomy Version : 1, 2 (BIP68 relative locktimes require v≥2), 3 (TRUC, BIP431). txid vs wtxid - — what spends and merkle root reference. - — what coinbase witness commitment uses (BIP141 witness merkle root). - For legacy non-segwit txs, . Inputs & outputs - Input spends a previous output ( ) and proves authorization via scriptSig + (for SegWit) witness stack. Value = whatever the prevout had — never serialized in the spending tx (must be looked up). - Output locks N sats to a . Address f…