Coin Smith
BITCOIN TRANSACTION BUILDER
Fixture Input
A fixture describes available coins (UTXOs), where to send Bitcoin, and fee preferences
Quick Guide
1.
UTXOs are your "coins" — individual amounts of Bitcoin your wallet controls
2.
Payments specify who to send Bitcoin to and how much
3.
Change is leftover Bitcoin sent back to your own wallet
4.
Fee rate determines how much you pay miners per unit of transaction size
Build a Bitcoin Transaction
Paste a fixture JSON on the left (or upload a file) and click "Build Transaction". The builder will select coins, calculate fees, and produce an unsigned PSBT — a portable format that can be safely signed later.