0-based position in the block's tx list
txid-tree merkle branch, display-order hex, bottom-up
OptionalwitnessReveal hop only: anchors the reveal's whole witness into the block's BIP-141 witness commitment, proving envelope bytes and numbering outright (indexProof 'wtxid'). Verifiers refuse the section on any other hop; later hops read nothing from witnesses.
Raw hex of the transactions referenced by this tx's inputs, aligned by input index. Entries are required for inputs 0..k, where k is the envelope input (hop 0) or the input spending the tracked satpoint (later hops); later entries may be omitted.
An empty string is not a permitted filler. A genealogy verifier uses every entry supplied on the reveal and on funding steps (SPEC-SAT, "Verifiers MUST use every prev tx supplied"), so a trailing empty entry fails to parse there rather than being skipped, and it refuses any entry on the terminal coinbase, whose null prevout no prev tx can fund. This builder emits trimmed non-empty hex only.