Blockchain transaction with OP_RETURN

0-decoded-transaction.json

{
  "result": {
    "txid": "62fe533dc5a506716affa362ca5cb7bba5232150ce5c676c56d6be6769022c52",
    "hash": "62fe533dc5a506716affa362ca5cb7bba5232150ce5c676c56d6be6769022c52",
    "size": 264,
    "vsize": 264,
    "version": 1,
    "locktime": 0,
    "vin": [
      {
        "txid": "2d7a9f0534ddac231ef1978bda388791c32321f7e14e18e7df3bbed261615f54",
        "vout": 0,
        "scriptSig": {
          "asm": "3045022100e7f32b8d7c260babaaf7cf022e6fb80397ca348854f274e16e74114e148872c302202ec0a57d67a99c656b23015afd0e58c9119b394b7e3eb5e09451ab7969e0894d[ALL] 033701fc7f242ae2dd63a18753518b6d1425e53496878924b6c0dc08d800af46ad",
          "hex": "483045022100e7f32b8d7c260babaaf7cf022e6fb80397ca348854f274e16e74114e148872c302202ec0a57d67a99c656b23015afd0e58c9119b394b7e3eb5e09451ab7969e0894d0121033701fc7f242ae2dd63a18753518b6d1425e53496878924b6c0dc08d800af46ad"
        },
        "sequence": 4294967295
      }
    ],
    "vout": [
      {
        "value": 0,
        "n": 0,
        "scriptPubKey": {
          "asm": "OP_RETURN 68656c6c6f206f6e652074776f20746872656520666f757220666976652073697820736576656e2065697468206e696e652074656e206576656c656e2e",
          "hex": "6a3d68656c6c6f206f6e652074776f20746872656520666f757220666976652073697820736576656e2065697468206e696e652074656e206576656c656e2e",
          "type": "nulldata"
        }
      },
      {
        "value": 1,
        "n": 1,
        "scriptPubKey": {
          "asm": "OP_DUP OP_HASH160 61ca8116d03694952a3ad252d53c695da7d95f61 OP_EQUALVERIFY OP_CHECKSIG",
          "hex": "76a91461ca8116d03694952a3ad252d53c695da7d95f6188ac",
          "reqSigs": 1,
          "type": "pubkeyhash",
          "addresses": [
            "mpS2RuNkAEALvMhksCa6fPpLVb5yCPanLu"
          ]
        }
      }
    ]
  },
  "error": null,
  "id": null
}

1-create-transaction.js

import bitcoin from "bitcoinjs-lib"

// buildTransaction :: KeyPair -> Array<Input> -> Array<Output> -> String
function buildTransaction (keyPair, inputs, outputs) {
  const tx = new bitcoin.TransactionBuilder(bitcoin.networks.testnet)
  inputs.forEach(([inputId, inputIndex]) => tx.addInput(inputId, inputIndex))
  outputs.forEach(([output, value]) => tx.addOutput(output, value))
  tx.sign(0, keyPair)
  return tx.build().toHex()
}

// Data to be stored in the OP_RETURN output:
const data = "Some data ... e.g. stringified JSON"
const opData = bitcoin.script.compile([
  OPS.OP_RETURN,
  data
])

// User's keyPair:
const keyPair = bitcoin.ECPair.fromWIF("cNY7A5QT4ZzLvYpaQ4JCUExaSMXPLEz9KpQWtczejyQBrzzxRSaR")

// Transaction as a HEX string:
const transactionWithOpReturn = buildTransaction(
  keyPair,
  [
    ['2d7a9f0534ddac231ef1978bda388791c32321f7e14e18e7df3bbed261615f54', 0]
  ],
  [
    [opData, 0],
    ['mpS2RuNkAEALvMhksCa6fPpLVb5yCPanLu', 1 * 100000000]
  ]
);
console.log('OP_RETURN transaction:', transactionWithOpReturn)

2-rawtransaction-hex.txt

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