Examples for Script Spend Taproot Tx

bitcoinjs / bitcoinjs-lib

A javascript Bitcoin library for node.js and browsers.

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Examples for Script Spend Taproot Tx #1814

Closed Sudz24 closed 2 years ago

Sudz24 commented 2 years ago

Hii,

The current samples under Taproot shows how to create and use a Key Spend Tx. Can you provide some example that works with Script Spend Tx as well? Thanks a lot.

motorina0 commented 2 years ago

The full taproot functionality still under review (not merged yet). You can find it in this PR: https://github.com/bitcoinjs/bitcoinjs-lib/pull/1742

Sudz24 commented 2 years ago

@motorina0 Thanks for the PR link, been going through the additions.

For the example here - https://gist.github.com/motorina0/e6bb1b32b3d5d2fc80e1bd63d5efea4f, I am not able to find the buildTapscriptFinalizer you imported.

You have said - "for the script-path spend a custom finalizer (FinalScriptsFunc) is required when a Taproot input is finalized. See test/psbt.utils.ts for such an example." But I can't find this file. Can you please point me towards the example.

junderw commented 2 years ago

Try looking at the PR branch:

https://github.com/bitcoincoretech/bitcoinjs-lib/blob/p2tr-v1/test/integration/taproot.spec.ts

Sudz24 commented 2 years ago

Thank you @junderw

However, I am facing the following error while trying to create a P2TR Address : Error: OP_1 5b6aed341b3959beb61e47738cc2e7e1ed721589ef38c2b657aafcf2a611b070 has no matching Address

Here is the snippet I tried: `

const seed1 = await bip39.mnemonicToSeed(seedPhrase1);

const BTC_TESTNET = bitcoin.networks.testnet;

const root1 = bip32.fromSeed(seed1, BTC_TESTNET)
const output = createKeySpendOutput(root1.publicKey);
const address = bitcoin.address.fromOutputScript(output, BTC_TESTNET);

console.log(address)`

Can you pls guide me on what's going wrong here?

motorina0 commented 2 years ago

The PR is still WIP, this might not be the final version:

taproot ins/outs require that bitcoin.initEccLib(ecc); is called beforehand
a sample of this call can be found in taproot.spec.ts

Sudz24 commented 2 years ago

Ahh yess! Now it works.

Thanks for your time.

Sudz24 commented 2 years ago

@motorina0 From the code examples, I observe that we require the scriptTree structure and the leafSript (for redeem) to be able to spend the balance. So does it mean I have to store the scriptTree somewhere to be able to use it later while spending?

And also, if you could take a scriptTree from the sample code and explain the way its structured, it would be of great help! The ASMs you have included other than the leafScript - ' OP_CHECKSIG', over here what are these ? I appreciate your efforts in solving the queries.

motorina0 commented 2 years ago

does it mean I have to store the scriptTree somewhere to be able to use it later while spending?

the leafSript has to be stored since it is part of the witness stack (penultimate item)
for the scriptTree you have two options
1. store the scriptTree
2. compute and store the controlBlock which contains the path in the tree for the leaf
  - the controlBlock is the last element in the witness stack. You can obtain it using the p2tr logic.

motorina0 commented 2 years ago

And also, if you could take a scriptTree from the sample code and explain the way its structured

The details about how the scriptTree is built can be found here:

https://github.com/bitcoin/bips/blob/master/bip-0341.mediawiki#constructing-and-spending-taproot-outputs

Sudz24 commented 2 years ago

Hi @motorina0 I noticed that P2TR Script Spend using OP_SEQUENCEVERIFY works without a problem. but using OP_CHECKLOCKTIMEVERIFY, the hex broadcast to spend the locked funds sometimes throw the error 'Non-Final' on mempool.space . Have you come across this before, could you help me understand this error?

junderw commented 2 years ago

Error 'Non-Final' means that you are not beyond the locktime.

If nLockTime says "Next tuesday" and you try to broadcast it. It will not propagate.