PSBT (BIP174 / BIP370 / BIP371) PSBT = a binary container for a transaction-in-progress, where one party constructs the skeleton, others contribute signatures, and a finalizer emits the broadcastable transaction. Versions - v0 (BIP174) — original. Magic . Tx is fully serialized in . - v2 (BIP370) — version field, per-input/output amount fields. Allows incremental construction without re-encoding the whole tx. Required for some workflows (BOLT12, advanced taproot). - BIP371 adds Taproot-specific fields (orthogonal to version). Roles | Role | Responsibility | |------|---------------| | Creator…