Sign and Broadcast Transaction

To sign and broadcast a transaction to the Aptos network, follow these steps:

Retrieve an unsigned serialized transaction in Base64 encrypted format.
Sign the transaction using the following code:

import {
  Aptos,
  Hex,
  Deserializer,
  RawTransaction,
  AptosConfig,
  Network,
  Ed25519PrivateKey,
  Account,
  SimpleTransaction,
  AccountAuthenticator,
} from "@aptos-labs/ts-sdk";

export function signTransaction(rawTx: string, privateKeyHex: string, aptosEnv: "mainnet" | "testnet"): string {
  if (!rawTx || !privateKeyHex) throw new Error("Missing raw transaction or private key");

  const config = new AptosConfig({
    network: aptosEnv === "mainnet" ? Network.MAINNET : Network.TESTNET,
    fullnode: aptosEnv === "mainnet" ? "https://api.mainnet.aptoslabs.com/v1" : "https://api.testnet.aptoslabs.com/v1",
  });

  const aptos = new Aptos(config);
  const signer = Account.fromPrivateKey({ privateKey: new Ed25519PrivateKey(privateKeyHex) });

  const transaction = new SimpleTransaction(
    RawTransaction.deserialize(new Deserializer(Hex.hexInputToUint8Array(rawTx)))
  );

  const signedTx: AccountAuthenticator = aptos.transaction.sign({ signer, transaction });

  return signedTx.toString();
}

const [, , rawTx, privKey, network] = process.argv;

if (!["mainnet", "testnet"].includes(network)) {
  throw new Error("Network must be 'mainnet' or 'testnet'");
}

console.log(signTransaction(rawTx, privKey, network as "mainnet" | "testnet"));

/**
 *  How to run this script:
 *  npx --yes -p @aptos-labs/[email protected] tsx signTransaction.ts <RAW_TX> <PRIVATE_KEY> <mainnet|testnet>
 **/
 
/**
 *  To run with env variables:
 *
 *  $ export RAW_TX= 'rawtxhere'
 *  $ export PRIVATE_KEY= 'privatekeyhere'
 *  $ export NETWORK= 'testnet' 
 *  $ npx --yes -p @aptos-labs/[email protected] tsx signTransaction.ts $RAW_TX $PRIVATE_KEY $NETWORK
 **/

Send the signed transaction to the Aptos network by making a POST request to /api/v1/aptos/{network}/transaction/send endpoint.

Example request:

curl --request POST \
     --url https://api.p2p.org/api/v1/aptos/mainnet/transaction/send \
     --header 'accept: application/json' \
     --head 'Authorization: Bearer <token>' \
     --header 'content-type: application/json' \
     --data '
{
  "transaction": "0x0020b92f133c8e4768d990f39853f1931eb0481ea289a985687f0b7e59e83456333140d386bb294c9a3ce9c8e6b49c4d6dba1bbf4d99b7803f9947bcec59855414d064bf138d29c14e884fb0e7f18c35fd39ffcae96fe767a3ddcbdc6603e407673006",
  "signature": "0x0020b92f133c8e4768d990f39853f1931eb0481ea289a985687f0b7e59e83456333140960e71dc383c5e0660940bbe476499ed8b64bc37efff47db1c20274f20b39d5858737269d6c7bcb1b9fc88dce0f0f7cc12b5e86516cf9f8d787827eaedf9f906"
}
'

transaction — signed transaction in the hexadecimal format which needs to be broadcasted to the network.
signature — delegator signature of the transaction.

Example response:

{
  "result": {
    "network": "mainnet",
    "senderAddress": "0xa571a5bc9b1bfd5fe58e6e09a5be251a3299985494d022959ce206f1f23f752e",
    "transaction": "0x0020b92f133c8e4768d990f39853f1931eb0481ea289a985687f0b7e59e83456333140d386bb294c9a3ce9c8e6b49c4d6dba1bbf4d99b7803f9947bcec59855414d064bf138d29c14e884fb0e7f18c35fd39ffcae96fe767a3ddcbdc6603e407673006",
    "status": "success",
    "transactionHash": "0x8d80b8ed85b578eeb873731101a926221701ee48318f6c9b83895f7ac1535640",
    "gas": {
      "unitPrice": 100,
      "maxGasLimit": 100,
      "used": 100
    },
    "createdAt": "2023-08-24T08:14:50.455Z"
  },
  "error": {}
}

network — Aptos network: mainnet or testnet.
senderAddress — transaction sender address.
transaction — signed transaction in hexadecimal format.
status — transaction status: success, failed.
transactionHash — hash of the transaction.
gas — computational effort required to execute the transaction, measured in gas units.
- unitPrice — price per unit of gas in Octas for processing the Aptos transaction.
- maxGasLimit — maximum gas limit for the transaction.
- used — amount of gas spent for the transaction.
createdAt — timestamp of the transaction in the ISO 8601 format.

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