decode.ts

import * as bitcon from "bitcoinjs-lib";
import { Address, Signer, Script, Tap, Tx } from "@cmdcode/tapscript";
import { util } from "@cmdcode/crypto-utils";

async function main() {
  // const tx = bitcon.Transaction.fromHex('02000000000101ff326033fad0629384a10ad29da02264f9ee599563536c3852e96fe241873b4d0000000000ffffffff01904106000000000022512038171c1ec905af3211a5d86db4ec059da7de9c3eed2f2611ed42b31115376f0501400f5797773cc0b30bbeb33a830404cfe4416d40bdf1a8168250d4959fc1ca374dba9bd3bad8bf46077f2ee64652d5091bbe8127314d74b0a67a574941b76d029900000000');
  // console.log("🚀 ~ main ~ tx:", tx.ins[0].witness[0].toString('hex'))
  // const scriptDecode = bitcon.script.decompile(tx.ins[0].witness[0])
  // console.log("🚀 ~ main ~ scriptDecode:", scriptDecode)
//   const addressTest = Address.fromScriptPubKey(Buffer.from('5120797117497f4653b902224dc682d0336eee23c6249dd714fc6d6942da1c37d5c8', 'hex'))
//   console.log("🚀 ~ main ~ address:", addressTest)
  const secret =
    "0a7d01d1c2e1592a02ea7671bb79ecd31d8d5e660b008f4b10e67787f4f24712";
  const seckey = util.getSecretKey(secret);
  const pubkey = util.getPublicKey(seckey, true);

  // Specify a basic script to use for testing.
  const script = [pubkey, "OP_CHECKSIG"];
  const sbytes = Script.encode(script);

  // For tapscript spends, we need to convert this script into a 'tapleaf'.
  const tapleaf = Tap.tree.getLeaf(sbytes);

  // Optional: There is a convenience method that converts scripts directly.
  const _tapleaf = Tap.encodeScript(script);

  // Generate a tapkey that includes our leaf script. Also, create a merlke proof
  // (cblock) that targets our leaf and proves its inclusion in the tapkey.
  const [tpubkey, cblock] = Tap.getPubKey(pubkey, { target: tapleaf });

  // A taproot address is simply the tweaked public key, encoded in bech32 format.
  const address = Address.p2tr.fromPubKey(tpubkey, "regtest");
  console.log("🚀 ~ main ~ address:", address)

  /* NOTE: To continue with this example, send 100_000 sats to the above address.
  You will also need to make a note of the txid and vout of that transaction,
  so that you can include that information below in the redeem tx.
*/

  const txdata = Tx.create({
    vin: [
      {
        // Use the txid of the funding transaction used to send the sats.
        txid: "181508e3be1107372f1ffcbd52de87b2c3e7c8b2495f1bc25f8cf42c0ae167c2",
        // Specify the index value of the output that you are going to spend from.
        vout: 0,
        // Also include the value and script of that ouput.
        prevout: {
          // Feel free to change this if you sent a different amount.
          value: 100_000,
          // This is what our address looks like in script form.
          scriptPubKey: ["OP_1", tpubkey],
        },
      },
    ],
    vout: [
      {
        // We are leaving behind 1000 sats as a fee to the miners.
        value: 99_000,
        // This is the new script that we are locking our funds to.
        scriptPubKey: Address.toScriptPubKey(
          "bcrt1q6zpf4gefu4ckuud3pjch563nm7x27u4ruahz3y"
        ),
      },
    ],
  });

  // For this example, we are signing for input 0 of our transaction,
  // using the untweaked secret key. We are also extending the signature
  // to include a commitment to the tapleaf script that we wish to use.
  const sig = Signer.taproot.sign(seckey, txdata, 0, { extension: tapleaf });
  console.log("🚀 ~ main ~ sig:", sig.hex)

  // Add the signature to our witness data for input 0, along with the script
  // and merkle proof (cblock) for the script.
  txdata.vin[0].witness = [sig.hex, script, cblock];

  // Check if the signature is valid for the provided public key, and that the
  // transaction is also valid (the merkle proof will be validated as well).
  const isValid = await Signer.taproot.verify(txdata, 0, { pubkey });
}

main();