bitcoincashautist A60AB5450353F40E

Understanding the UTXO Model: A Guide for Bitcoin Cash Developers

Introduction

Welcome to Bitcoin Cash development! If you're coming from other blockchain platforms or traditional web development, the UTXO (Unspent Transaction Output) model might be a new concept to grasp. This guide will break down how UTXOs work in Bitcoin Cash and provide insights on how to design effective smart contracts using this model.

What is a UTXO?

In Bitcoin Cash, think of UTXOs as individual digital bills in your wallet. Unlike account-based blockchains (like Ethereum) that track a single balance for each address, Bitcoin Cash tracks specific "bills" of cryptocurrency.

Keybase proof

I hereby claim:

I am A60AB5450353F40E on github.
I am bchautist (https://keybase.io/bchautist) on keybase.
I have a public key whose fingerprint is 175C 7285 0B9D 3B15 8913 D5CE A60A B545 0353 F40E

To claim this, I am signing this object:

	{
	"$schema": "https://ide.bitauth.com/authentication-template-v0.schema.json",
	"description": "Fungible token management contract, consisting of 3 outputs:\n- tracker NFT (invariant category-specific P2SH address)\n- owner NFT (user-set address)\n- baton NFT (reserved supply and metadata carrier)\n\nOwner NFT can be transferred independently, while spending tracker+baton requires the owner is spent in the same transaction.",
	"name": "One Token Standard v0.1",
	"entities": {
	"baton": {
	"description": "",
	"name": "baton",
	"scripts": [
	"baton_current"

	{
	"$schema": "https://ide.bitauth.com/authentication-template-v0.schema.json",
	"description": "Proof of concept for a token constructor covenant that enforces SLPv1 specification and metadata format",
	"name": "SLPv1 CashTokens Constructor",
	"entities": {},
	"scripts": {
	"unlock_constructor": {
	"name": "Unlock",
	"script": "<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

	{
	"$schema": "https://bitauth.com/schemas/authentication-template-v0.schema.json",
	"description": "Public P2SH covenant to create an \"one token standard\" native token baton, one that is limited to 1 baton UTXO.\nThe only way to spend from the covenant is to spend the UTXO as a group genesis input matching the required parameters and verifying that exactly 1 baton \"change\" is being created.",
	"name": "Genesis from Covenant",
	"entities": {},
	"scripts": {
	"helper_group_genesis_generator": {
	"name": "HELPER: GROUP GENESIS GENERATOR",
	"script": "// # Poor man's group genesis generator\n// Set prevout and genesis parameters, and then manually roll the nonce\n// until the groupGenType matches.\n\n// Part 1. - genesis input's prevout reference\n // Prevout hash\n <0x699099d656be426a9618d732fd21e626667361d463ba9cae07d9517fc1768582>\n // Prevout index\n <0x00000000> OP_CAT\n OP_HASH256\n// Part 2. - genesis input's prevout\n // Prevout satoshi amount\n <0xa086010000000

	{
	"$schema": "https://bitauth.com/schemas/authentication-template-v0.schema.json",
	"description": "The user pays 10,000 satoshis to get a token. They can transfer that token to use 2-of-3, then back to single sig, then deposit the token and get back their 10,000 satoshis from the parent covenant.",
	"name": "Jason's Challenge",
	"entities": {},
	"scripts": {
	"depository_corporation": {
	"name": "DEPOSITORY CORPORATION",
	"script": "// # Unlocking Script\n// Token burn output index\n<0x01>\n// Part 3. of groupID preimage (genesis input parameters)\n<0x0000000001008d110100000000000000>\n// Part 1. of groupID preimage (hash of genesis input's prevout ref.)\n<0xe69b80d54c704b204143089c4e00ee86fa5a4f897878fe1ce0e6661fbc4e7067>\n// Genesis input's prevout owner (PKH)\n<0x0233bc976da9a9e30ff18b35195693b938e06eaf>\n// Genesis input's prevout satoshi amount\n<0xa086010000000000>\n// Redeem Script Raw\n<0x01177E02A9147E0376A9147B7E0388ADAB7E4c5676A9140233BC976DA9A9E30FF18B35195693B938E06EAF88ADABC0