@ignored/tx
v4.0.0-beta.6
Published
A simple module for creating, manipulating and signing Ethereum transactions
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@ethereumjs/tx
| Implements schema and functions related to Ethereum's transaction. | | ------------------------------------------------------------------ |
Note: this README
reflects the state of the library from v3.0.0
onwards. See README
from the standalone repository for an introduction on the last preceding release.
Installation
To obtain the latest version, simply require the project using npm
:
npm install @ethereumjs/tx
Usage
Static Constructor Methods
To instantiate a tx it is not recommended to use the constructor directly. Instead each tx type comes with the following set of static constructor methods which helps on instantiation depending on the input data format:
public static fromTxData(txData: TxData, opts: TxOptions = {})
: instantiate from a data dictionarypublic static fromSerializedTx(serialized: Buffer, opts: TxOptions = {})
: instantiate from a serialized txpublic static fromValuesArray(values: Buffer[], opts: TxOptions = {})
: instantiate from a values array
See one of the code examples on the tx types below on how to use.
All types of transaction objects are frozen with Object.freeze()
which gives you enhanced security and consistency properties when working with the instantiated object. This behavior can be modified using the freeze
option in the constructor if needed.
Chain and Hardfork Support
The Transaction
constructor receives a parameter of an @ethereumjs/common
object that lets you specify the chain and hardfork to be used. If there is no Common
provided the chain ID provided as a paramter on typed tx or the chain ID derived from the v
value on signed EIP-155 conforming legacy txs will be taken (introduced in v3.2.1
). In other cases the chain defaults to mainnet
.
Base default HF (determined by Common
): merge
Starting with v3.2.1
the tx library now deviates from the default HF for typed tx using the following rule: "The default HF is the default HF from Common
if the tx type is active on that HF. Otherwise it is set to the first greater HF where the tx is active."
Supported Hardforks:
| Hardfork | Introduced | Description |
| ---------------- | ---------- | ------------------------------------------------------------------------------------------------------- |
| london
| v3.2.0
| EIP-1559
Transactions |
| berlin
| v3.1.0
| EIP-2718
Typed Transactions, Optional Access Lists Tx Type EIP-2930
|
| muirGlacier
| v2.1.2
| - |
| istanbul
| v2.1.1
| Support for reduced non-zero call data gas prices (EIP-2028) |
| spuriousDragon
| v2.0.0
| EIP-155
replay protection (disable by setting HF pre-spuriousDragon
) |
Standalone EIPs
The following "standalone" EIPs are supported by the library can be manually activated using a respectively initialized Common
instance, e.g.:
const common = new Common({ chain: Chain.Mainnet, hardfork: Hardfork.London, eips: [3860] })
- EIP-3860: Limit and meter initcode (
experimental
)
Transaction Types
This library supports the following transaction types (EIP-2718):
FeeMarketEIP1559Transaction
(EIP-1559, gas fee market)AccessListEIP2930Transaction
(EIP-2930, optional access lists)Transaction
, the Ethereum standard tx up toberlin
, now referred to as legacy txs with the introduction of tx types
Gas Fee Market Transactions (EIP-1559)
- Class:
FeeMarketEIP1559Transaction
- Activation:
london
- Type:
2
This is the recommended tx type starting with the activation of the london
HF, see the following code snipped for an example on how to instantiate:
import { Chain, Common, Hardfork } from '@ethereumjs/common'
import { FeeMarketEIP1559Transaction } from '@ethereumjs/tx'
const common = new Common({ chain: Chain.Mainnet, hardfork: Hardfork.London })
const txData = {
data: '0x1a8451e600000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000',
gasLimit: '0x02625a00',
maxPriorityFeePerGas: '0x01',
maxFeePerGas: '0xff',
nonce: '0x00',
to: '0xcccccccccccccccccccccccccccccccccccccccc',
value: '0x0186a0',
v: '0x01',
r: '0xafb6e247b1c490e284053c87ab5f6b59e219d51f743f7a4d83e400782bc7e4b9',
s: '0x479a268e0e0acd4de3f1e28e4fac2a6b32a4195e8dfa9d19147abe8807aa6f64',
chainId: '0x01',
accessList: [],
type: '0x02',
}
const tx = FeeMarketEIP1559Transaction.fromTxData(txData, { common })
Access List Transactions (EIP-2930)
- Class:
AccessListEIP2930Transaction
- Activation:
berlin
- Type:
1
This transaction type has been introduced along the berlin
HF. See the following code snipped for an example on how to instantiate:
import { Chain, Common, Hardfork } from '@ethereumjs/common'
import { AccessListEIP2930Transaction } from '@ethereumjs/tx'
const common = new Common({ chain: Chain.Mainnet, hardfork: Hardfork.Berlin })
const txData = {
data: '0x1a8451e600000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000',
gasLimit: '0x02625a00',
gasPrice: '0x01',
nonce: '0x00',
to: '0xcccccccccccccccccccccccccccccccccccccccc',
value: '0x0186a0',
v: '0x01',
r: '0xafb6e247b1c490e284053c87ab5f6b59e219d51f743f7a4d83e400782bc7e4b9',
s: '0x479a268e0e0acd4de3f1e28e4fac2a6b32a4195e8dfa9d19147abe8807aa6f64',
chainId: '0x01',
accessList: [
{
address: '0x0000000000000000000000000000000000000101',
storageKeys: [
'0x0000000000000000000000000000000000000000000000000000000000000000',
'0x00000000000000000000000000000000000000000000000000000000000060a7',
],
},
],
type: '0x01',
}
const tx = AccessListEIP2930Transaction.fromTxData(txData, { common })
For generating access lists from tx data based on a certain network state there is a reportAccessList
option
on the Vm.runTx()
method of the @ethereumjs/vm
TypeScript
VM implementation.
Legacy Transactions
- Class:
Transaction
- Activation:
chainstart
(with modifications along the road, see HF section below) - Type:
0
(internal)
Legacy transaction are still valid transaction within Ethereum mainnet
but will likely be deprecated at some point.
See this example script or the following code example on how to use.
import { Chain, Common, Hardfork } from '@ethereumjs/common'
import { Transaction } from '@ethereumjs/tx'
const txParams = {
nonce: '0x00',
gasPrice: '0x09184e72a000',
gasLimit: '0x2710',
to: '0x0000000000000000000000000000000000000000',
value: '0x00',
data: '0x7f7465737432000000000000000000000000000000000000000000000000000000600057',
}
const common = new Common({ chain: Chain.Mainnet, hardfork: Hardfork.Istanbul })
const tx = Transaction.fromTxData(txParams, { common })
const privateKey = Buffer.from(
'e331b6d69882b4cb4ea581d88e0b604039a3de5967688d3dcffdd2270c0fd109',
'hex'
)
const signedTx = tx.sign(privateKey)
const serializedTx = signedTx.serialize()
Transaction Factory
If you only know on runtime which tx type will be used within your code or if you want to keep your code transparent to tx types, this library comes with a TransactionFactory
for your convenience which can be used as follows:
import { Chain, Common, Hardfork } from '@ethereumjs/common'
import { TransactionFactory } from '@ethereumjs/tx'
const common = new Common({ chain: Chain.Mainnet, hardfork: Hardfork.Berlin })
const txData = {} // Use data from the different tx type examples
const tx = TransactionFactory.fromTxData(txData, { common })
if (tx.supports(Capability.EIP2930AccessLists)) {
// Do something which only makes sense for txs with support for access lists
}
The correct tx type class for instantiation will then be chosen on runtime based on the data provided as an input.
TransactionFactory
supports the following static constructor methods:
public static fromTxData(txData: TxData | AccessListEIP2930TxData, txOptions: TxOptions = {}): TypedTransaction
public static fromSerializedData(data: Buffer, txOptions: TxOptions = {}): TypedTransaction
public static fromBlockBodyData(data: Buffer | Buffer[], txOptions: TxOptions = {})
Sending a Transaction
L2 Support
This library has been tested to work with various L2 networks (v3.3.0
+). All predefined supported custom chains introduced with Common
v2.4.0
or higher are supported, the following is a simple example to send a tx to the xDai chain:
import { Transaction } from '@ethereumjs/tx'
import { Common } from '@ethereumjs/common'
const from = 'PUBLIC_KEY'
const PRIV_KEY = process.argv[2]
const to = 'DESTINATION_ETHEREUM_ADDRESS'
const common = Common.custom(CustomChain.xDaiChain)
const txData = {
from,
nonce: 0,
gasPrice: 1000000000,
gasLimit: 21000,
to,
value: 1,
}
const tx = Transaction.fromTxData(txData, { common })
const signedTx = tx.sign(Buffer.from(PRIV_KEY, 'hex'))
The following L2 networks have been tested to work with @ethereumjs/tx
, see usage examples as well as some notes on pecularities in the issues linked below:
| L2 Network | Common name | Issue |
| ------------------------ | ------------------------------------- | ----------------------------------------------------------------------- |
| Arbitrum Rinkeby Testnet | CustomChain.ArbitrumRinkebyTestnet
| #1290 |
| Polygon Mainnet | CustomChain.PolygonMainnet
| #1289 |
| Polygon Mumbai Testnet | CustomChain.PolygonMumbai
| #1289 |
| xDai Chain | Common.xDaiChain
| #1323 |
| Optimistic Kovan | Common.OptimisticKovan
| #1554 |
| Optimistic Ethereum | Common.OptimisticEthereum
| #1554 |
Note: For Optimistic Kovan and Optimistic Ethereum, the London hardfork has not been implemented so transactions submitted with a baseFee
will revert.
The London hardfork is targeted to implement on Optimism in Q1.22.
For a non-predefined custom chain it is also possible to just provide a chain ID as well as other parameters to Common
:
const common = Common.custom({ chainId: 1234 })
Special Topics
Signing with a hardware or external wallet
To sign a tx with a hardware or external wallet use tx.getMessageToSign(false)
to return an EIP-155 compliant unsigned tx.
A legacy transaction will return a Buffer list of the values, and a Typed Transaction (EIP-2718) will return the serialized output.
Here is an example of signing txs with @ledgerhq/hw-app-eth
as of v6.5.0
:
import { Transaction, FeeMarketEIP1559Transaction } from '@ethereumjs/tx'
import { Chain, Common } from '@ethereumjs/common'
import { bufArrToArr } from '@ethereumjs/util'
import { RLP } from '@ethereumjs/rlp'
import Eth from '@ledgerhq/hw-app-eth'
const eth = new Eth(transport)
const common = new Common({ chain: Chain.Rinkeby })
let txData: any = { value: 1 }
let tx: Transaction | FeeMarketEIP1559Transaction
let unsignedTx: Buffer[] | Buffer
let signedTx: typeof tx
const bip32Path = "44'/60'/0'/0/0"
const run = async () => {
// Signing a legacy tx
tx = Transaction.fromTxData(txData, { common })
unsignedTx = tx.getMessageToSign(false)
unsignedTx = Buffer.from(RLP.encode(bufArrToArr(unsignedTx))) // ledger signTransaction API expects it to be serialized
let { v, r, s } = await eth.signTransaction(bip32Path, unsignedTx)
txData = { ...txData, v, r, s }
signedTx = Transaction.fromTxData(txData, { common })
let from = signedTx.getSenderAddress().toString()
console.log(`signedTx: 0x${signedTx.serialize().toString('hex')}\nfrom: ${from}`)
// Signing a 1559 tx
txData = { value: 1 }
tx = FeeMarketEIP1559Transaction.fromTxData(txData, { common })
unsignedTx = tx.getMessageToSign(false)
;({ v, r, s } = await eth.signTransaction(bip32Path, unsignedTx)) // this syntax is: object destructuring - assignment without declaration
txData = { ...txData, v, r, s }
signedTx = FeeMarketEIP1559Transaction.fromTxData(txData, { common })
from = signedTx.getSenderAddress().toString()
console.log(`signedTx: ${signedTx.serialize().toString('hex')}\nfrom: ${from}`)
}
run()
Fake Transaction
Creating a fake transaction for use in e.g. VM.runTx()
is simple, just overwrite getSenderAddress()
with a custom Address
like so:
import { Address } from '@ethereumjs/util'
import { Transaction } from '@ethereumjs/tx'
_getFakeTransaction(txParams: TxParams): Transaction {
const from = Address.fromString(txParams.from)
delete txParams.from
const opts = { common: this._common, freeze: false }
const tx = Transaction.fromTxData(txParams, opts)
// override getSenderAddress
tx.getSenderAddress = () => { return from }
return tx
}
API
Docs
Generated TypeDoc API Documentation
BigInt Support
Starting with v4 the usage of BN.js for big numbers has been removed from the library and replaced with the usage of the native JS BigInt data type (introduced in ES2020
).
Please note that number-related API signatures have changed along with this version update and the minimal build target has been updated to ES2020
.
EthereumJS
See our organizational documentation for an introduction to EthereumJS
as well as information on current standards and best practices. If you want to join for work or carry out improvements on the libraries, please review our contribution guidelines first.