Raw Transaction

Basics

• Prepare tx parameters
• Create transaction
• Sign with private key
• Serialize and send

Transaction Parameters

See https://github.com/ethereumjs/ethereumjs-tx/blob/master/docs/index.md for format

Common parameters

• nonce - increase per tx per account
  • eth.getTransactionCount(<account>)
• gasPrice - check https://etherscan.io/gastracker
• gasLimit - https://medium.com/@piyopiyo/how-to-get-ethereum-block-gas-limit-eba2c8f32ce

Send transaction

• to: '0xdeadbeef.....'
• value: '12345...'

Contract deployment

• No "to" and "value"
• data : encoded payload, in correct format...

(with go: https://medium.com/@akshay_111meher/creating-offline-raw-transactions-with-go-ethereum-8d6cc8174c5d

with Javascript Web3 0.2x.x - see "web3.eth.contract" and "MyContract.new.getData" to deploy manually

also https://ethereum.stackexchange.com/questions/36358/how-to-properly-create-a-raw-transaction-and-sign-it-using-web3-in-browser?rq=1

https://gist.github.com/tomconte/6ce22128b15ba36bb3d7585d5180fba0

)

Contract method

(with Javascript Web3 0.2x.x - see "web3.eth.contract" and "myContractInstance.myMethod.getData")

Create transaction

const ethTx = require('ethereumjs-tx');

...

const tx = new ethTx(txParams);

Sign with Private Key

const privKey = Buffer.from('deadbeef000000...', 'hex');

tx.sign(privKey);

Or from account, see https://ethereum.stackexchange.com/questions/3386/create-and-sign-offline-raw-transactions

var Accounts = require('web3-eth-accounts');

var accounts = new Accounts();

accounts.signTransaction(...)

Serialize and Send

const serializedTx = tx.serialize();

const rawTx = '0x' + serializedTx.toString('hex');

console.log(rawTx)

This gets us a raw transaction string, which can be used on geth console

eth.sendRawTransaction(<rawTx string>)

Alternatively,

• web3.eth.sendRawTransaction API
• https://etherscan.io/pushTx