play9.ts

// How to run:
// npm install -g ts-node typescript '@types/node'
// ts-node play9.ts

import * as ecc from 'tiny-secp256k1';
import { ECPairFactory } from 'ecpair'

import { Psbt } from './ts_src/psbt'
import { p2tr } from './ts_src/payments/index'
import { testnet as network } from './ts_src/networks'
import * as bscript from './ts_src/script'
import { buildTapscriptFinalizer, toXOnly } from './test/psbt.utils';


const ECPair = ECPairFactory(ecc);
const hex = (s: string) => Buffer.from(s, 'hex')

// one P2TR input, one P2TR output
const inP2trKey = ECPair.fromPrivateKey(hex('accaf12e04e11b08fc28f5fe75b47ea663843b698981e31f0000000000000000'))
const outP2trKey = ECPair.fromPrivateKey(hex('900afde76badc8914c9940379c74857d70b4d7da590097280000000000000000'))

// the leaf to be spent
const leafKey = ECPair.fromPrivateKey(hex('82fd530c9eb33570c7e05ca5e80b740bcf1118e8f4c73d440000000000000000'))
const leafScriptAsm = `${toXOnly(leafKey.publicKey).toString('hex')} OP_CHECKSIG`
const leafScript = bscript.fromASM(leafScriptAsm);

// Tap tree. We are going to spend one leaf
const scriptTree: any = [
    [
        {
            "output": bscript.fromASM("50929b74c1a04954b78b4b6035e97a5e078a5a0f28ec96d547bfee9ace803ac0 OP_CHECKSIG")
        },
        [
            {
                "output": bscript.fromASM("50929b74c1a04954b78b4b6035e97a5e078a5a0f28ec96d547bfee9ace803ac1 OP_CHECKSIG")
            },
            {
                "output": bscript.fromASM("2258b1c3160be0864a541854eec9164a572f094f7562628281a8073bb89173a7 OP_CHECKSIG")
            }
        ]
    ],
    [
        {
            "output": bscript.fromASM("50929b74c1a04954b78b4b6035e97a5e078a5a0f28ec96d547bfee9ace803ac2 OP_CHECKSIG")
        },
        [
            {
                "output": bscript.fromASM("50929b74c1a04954b78b4b6035e97a5e078a5a0f28ec96d547bfee9ace803ac3 OP_CHECKSIG")
            },
            [
                {
                    "output": bscript.fromASM("50929b74c1a04954b78b4b6035e97a5e078a5a0f28ec96d547bfee9ace803ac4 OP_CHECKSIG")
                },
                {
                    "output": leafScript
                }
            ]
        ]
    ]
]

const redeem = {
    output: leafScript,
    redeemVersion: 192,
};

// script-path spend from input
const inP2tr = p2tr({ internalPubkey: toXOnly(inP2trKey.publicKey), scriptTree, redeem, network }, { eccLib: ecc })
// send to key-path only spent
const outP2tr = p2tr({ internalPubkey: toXOnly(outP2trKey.publicKey), network }, { eccLib: ecc })
console.log('### inP2tr.address', inP2tr.address)

// Build the transaction
const psbt = new Psbt({ network, eccLib: ecc })

// spend p2tr
psbt.addInput({
    hash: hex('d17efa28568bb71533c2a2a85252a617be2d98576fd6e87557b8d0a8503454c4').reverse(),
    index: 1,
}).updateInput(0, {
    witnessScript: redeem.output,
    witnessUtxo: { script: inP2tr.output!, value: 10000 }
})

psbt.addOutput({
    address: outP2tr.address!,
    value: 9000
})


psbt.signInput(0, leafKey)
const finalScriptFunc = buildTapscriptFinalizer(inP2trKey.publicKey, scriptTree, network)
psbt.finalizeInput(0, finalScriptFunc)

const tx = psbt.extractTransaction()
const rawTx = tx.toBuffer()
console.log('### txId', tx.getId())
console.log('### rawTx', rawTx.toString('hex'))
// broadcast with: https://mempool.space/testnet/tx/push

Receive funds to taproot address. Testnet TX here
Script-path spend. Testnet TX here

Witness for script-path spend (app here):