Coin Selection Coin selection chooses which subset of available UTXOs to spend for a target amount + fee. Trade-offs: fee minimization, privacy, change-output dust avoidance, UTXO-set hygiene. Inputs to the algorithm - Target amount ( ). - Fee rate ( sat/vB). - Available UTXOs . - Per-output-type vsize constants (P2WPKH 68 vB to spend, P2TR 57 vB). - Min change amount (dust threshold + small overhead). Algorithm 1: Branch and Bound (BnB) Bitcoin Core's primary algorithm (Murch 2017). Goal: find a subset that sums exactly to , avoiding change output entirely. Backtracking with pruning. If BnB…