Fetching bitcoin tx metadata needed for `clarity-bitcoin-lib-v5` contract's `was-tx-mined-compact` function parameters.

btc-tx-data.js

import mempoolJS from "@mempool/mempool.js"
import { Transaction } from "bitcoinjs-lib"

const {
  bitcoin: { transactions, blocks }
} = mempoolJS({
  hostname: "mempool.space"
})

export const getTxHex = async txid => {
  const txHex = await transactions.getTxHex({ txid })

  return txHex
}

export const getTxMerkleProof = async txid => {
  // Using mempool.space's GET /api/tx/:txid/merkle-proof
  const { block_height, merkle, pos } = await transactions.getTxMerkleProof({ txid })

  return { block_height, merkle, pos }
}

export const getBlkHeader = async height => {
  let blockHash = await blocks.getBlockHeight({ height })

  // Using mempool.space's GET /api/block/:hash/header
  const blockHeader = await blocks.getBlockHeader({ hash: blockHash })

  return { blockHash, blockHeader }
}

export const removeWitnessData = txHex => {
  const tx = Transaction.fromHex(txHex)

  if (!tx.hasWitnesses()) {
    return txHex
  }

  // Create a new empty transaction
  const newTx = new Transaction()

  // Copy version from original transaction
  newTx.version = tx.version

  // Copy inputs from original transaction
  tx.ins.forEach(input => {
    newTx.addInput(input.hash, input.index, input.sequence, input.script)
  })

  // Copy outputs from original transaction
  tx.outs.forEach(output => {
    newTx.addOutput(output.script, output.value)
  })

  // Copy locktime from original transaction
  newTx.locktime = tx.locktime

  return newTx.toHex()
}

clarity-bitcoin.js

import {
  callReadOnlyFunction,
  bufferCV,
  uintCV,
  tupleCV,
  listCV,
  cvToString,
} from "@stacks/transactions"
import { StacksMainnet } from "@stacks/network"
import { hexToBytes } from "@stacks/common"
import { getTxHex, getTxMerkleProof, getBlkHeader, removeWitnessData } from "./btc-tx-data.js"
import { mainnetAddress } from "./wallets.js"

const mainnet = new StacksMainnet()

// From read-only function of below clarity-bitcoin implementation contract:
const contractAddress = "SP2PABAF9FTAJYNFZH93XENAJ8FVY99RRM50D2JG9"
const contractName = "clarity-bitcoin-lib-v5"
const functionName = "was-tx-mined-compact"

// fetching btc tx details. You can replace this with any bitcoin transaction id.
let txid = "7ad7414063ab0f7ce7d5b1b6b4a87091094bd0e9be0e6a44925a48e1eb2ca51c"

// fetching and returning non-witness tx hex
let fullTxHex = await getTxHex(txid)
let txHex = removeWitnessData(fullTxHex)

let { block_height, merkle, pos } = await getTxMerkleProof(txid)

let { blockHeader } = await getBlkHeader(block_height)

let txIndex = pos
let hashes = merkle.map(hash => bufferCV(hexToBytes(hash).reverse()))
let treeDepth = merkle.length

let functionArgs = [
  // (height)
  uintCV(block_height),
  // (tx)
  bufferCV(Buffer.from(txHex, "hex")),
  // (header)
  bufferCV(Buffer.from(blockHeader, "hex")),
  // (proof)
  tupleCV({
    "tx-index": uintCV(txIndex),
    hashes: listCV(hashes),
    "tree-depth": uintCV(treeDepth)
  })
]

let result = await callReadOnlyFunction({
  contractAddress,
  contractName,
  functionName,
  functionArgs,
  network: mainnet,
  // this could be any principal address
  senderAddress: mainnetAddress
})

console.log(cvToString(result))