Bitcoin 提供方

const psbtHex = transactionRequest.data;

// Create PSBT object from hex data
const psbt = Psbt.fromHex(psbtHex, { network: networks.bitcoin });

// Find OP_RETURN output in the transaction outputs
const opReturnOutput = psbt.txOutputs.find((output) => {
  if (output?.script) {
    // Convert the output script to hex string for checking
    const scriptHex = Array.from(output.script)
      .map((b) => b.toString(16).padStart(2, "0"))
      .join("");

    // Check if script starts with OP_RETURN opcode (0x6a)
    return scriptHex.startsWith("6a");
  }
  return false;
});

// If an OP_RETURN output exists, decode its script data as UTF-8 text (memo)
const memo = opReturnOutput?.script
  ? new TextDecoder().decode(
      new Uint8Array(Object.values(opReturnOutput.script))
    )
  : undefined;