micro-eth-signer
Create, sign and validate Ethereum transactions & addresses with minimum deps.
- Tiny: 500 lines of code, 3KB gzipped
- 3 dependencies: SHA-3, RLP & secp256k1, 13KB gzipped with all deps bundled
- No network code in main package: allows simpler audits and offline usage
- Validated against 3MB of ethers test vectors
- Using audited noble cryptography under the hood
Check out all web3 utility libraries: ETH, BTC, SOL, micro-web3, tx-tor-broadcaster
Usage
npm install micro-eth-signer
We support all major platforms and runtimes. For Deno, ensure to use npm specifier. For React Native, you may need a polyfill for getRandomValues. If you don't like NPM, a standalone eth-signer.js is also available.
import { Address, Transaction } from 'micro-eth-signer';
const tx = new Transaction({
to: '0xdf90dea0e0bf5ca6d2a7f0cb86874ba6714f463e',
maxFeePerGas: 100n * 10n ** 9n, // 100 gwei in wei
value: 10n ** 18n, // 1 eth in wei
nonce: 1,
maxPriorityFeePerGas: 0,
chainId: 1
});
// keys, messages & other inputs can be Uint8Arrays or hex strings
// Uint8Array.from([0xde, 0xad, 0xbe, 0xef]) === 'deadbeef'
const privateKey = '6b911fd37cdf5c81d4c0adb1ab7fa822ed253ab0ad9aa18d77257c88b29b718e';
const signedTx = tx.sign(privateKey);
const { hash, hex } = signedTx;
// Strings can be used also
// tx = new Transaction({"nonce": "0x01"})
// Same goes to serialized representation
// tx = new Transaction('0xeb018502540be40082520894df90dea0e0bf5ca6d2a7f0cb86874ba6714f463e872386f26fc1000080808080');
// Various tx properties
console.log('Need wei', tx.upfrontCost); // also, tx.fee, tx.amount, tx.sender, etc
// Address manipulation
const addr = Address.fromPrivateKey(privateKey);
const pubKey = signedTx.recoverSenderPublicKey();
console.log('Verified', Address.verifyChecksum(addr));
console.log('addr is correct', signedTx.sender, signedTx.sender == addr);
console.log(signedTx);
// London style txs, EIP 1559
const legacyTx = new Transaction({
to: '0xdf90dea0e0bf5ca6d2a7f0cb86874ba6714f463e',
gasPrice: 100n * 10n ** 9n, // 100 gwei in wei
value: 10n ** 18n, // 1 eth in wei
nonce: 1
}, undefined, undefined, 'legacy');
const berlinTx = new Transaction({
to: '0xdf90dea0e0bf5ca6d2a7f0cb86874ba6714f463e',
maxFeePerGas: 100n * 10n ** 9n, // 100 gwei in wei
maxPriorityFeePerGas: 1n * 10n ** 9n, // 1 gwei in wei
value: 10n ** 18n, // 1 eth in wei
nonce: 1,
// the field can also be used in eip1559 txs
accessList: [{
"address": "0x123456789a123456789a123456789a123456789a",
"storageKeys": [
"0x0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
]
}]
}, undefined, undefined, 'eip2930');
API
Address
Represents ETH address and has following methods:
Address.fromPrivateKey(privateKey: string | Uint8Array): string
- create address from private keyAddress.fromPublicKey(publicKey: string | Uint8Array): string
- creates address from public keyAddress.checksum(nonChecksummedAddress: string): string
- creates checksummed address from non-checksummed addressAddress.verifyChecksum(address: string): boolean
- verifies checksummed & non-checksummed address
Usage:
const addr = "0x0089d53f703f7e0843953d48133f74ce247184c2";
const addrc = Address.checksum(addr) // 0x0089d53F703f7E0843953D48133f74cE247184c2
Address.verifyChecksum(addrc) // true
Address.verifyChecksum(addr) // true also (non-checksummed)
Address.fromPrivateKey("0687640ee33ef844baba3329db9e16130bd1735cbae3657bd64aed25e9a5c377")
// 0xD4fE407789e11a27b7888A324eC597435353dC35
Address.fromPublicKey("030fba7ba5cfbf8b00dd6f3024153fc44ddda93727da58c99326eb0edd08195cdb")
// 0xD4fE407789e11a27b7888A324eC597435353dC35
Transaction
Represents unsigned & signed ETH transactions. They are serialized & deserialized using RLP. Here's an example of the same transaction in raw state, and serialized state:
// raw
{
"nonce": "0x01", "gasLimit": "0x5208", "gasPrice": "0x02540be400",
"to": "0xdf90dea0e0bf5ca6d2a7f0cb86874ba6714f463e",
"value": "2386f26fc10000", "data": "0x"
}
// serialized
"0xeb018502540be40082520894df90dea0e0bf5ca6d2a7f0cb86874ba6714f463e872386f26fc1000080808080"
You can use either of those to initialize new Transaction
. There are a few methods available:
new Transaction(serialized[, chain, hardfork, type])
- creates transaction from Raw TX string.chain
: optional argument (default ismainnet
;ropsten
,rinkeby
,goerli
,kovan
etc)hardfork
: optional argument (default islondon
). The only place we're checking forhardfork
is the replay protection code. There are very old transactions that don't support replay protection, you'll probably won't need themtype
: optional argument (default iseip1559
). Can be eitherlegacy
,eip2930
, oreip1559
(Berlin and London style transactions with access lists andmaxFeePerGas
/maxPriorityFeePerGas
)
new Transaction(rawTx[, chain, hardfork, type])
- creates transaction from Raw TX data.rawTx
must have fieldsto
,value
,nonce
,gasLimit
rawTx
must havemaxFeePerGas
(eip1559 txs) orgasPrice
(berlin & legacy txs)to
is recipient's addressvalue
is amount to send in weinonce
is sender's nonce in numbergasLimit
is transaction's Gas Limit in wei (minimum is21000
)maxFeePerGas
is eip1559 transaction's max acceptable gas price in wei (100 gwei is100 * 10 ** 9
). Not applicable to legacy transactionsmaxPriorityFeePerGas
is eip1559 transaction's max acceptable tip in wei. Not applicable to legacy transactionsgasPrice
is legacy transaction's Gas Price in wei. Not applicable to eip1559 transactionsdata
is transaction's data if it's calling some smart contractsaccessList
is transaction's Access List, a list of addresses that its smart contract call touches. Basically an array of strings:["0x123...", "0x456..."]
. Not applicable to legacy transactions
Transaction#sign(privateKey: string | Uint8Array): Promise<Transaction>
— creates new transaction with same data, but signed by following private keyTransaction#recoverSenderPublicKey(): string
— recovers sender's public key from signed transaction
Transaction Properties
isSigned: boolean
- whether tx is signed with private keygasPrice: bigint
- legacy wei/gasmaxFeePerGas: bigint
,maxPriorityFeePerGas: bigint
- eip1559 wei/gasamount: bigint
- amount (akavalue
) in weifee: bigint
- fee in wei (maxFeePerGas
*gasLimit
orgasPrice
*gasLimit
)upfrontCost: bigint
- amount + fee in wei, combinedto: string
- address that receives the txnonce: number
- account's noncesender: string
- address that sends the tx. Only signed txs have the fieldhash: string
- signed tx hash used in block explorers. Example:50b6e7b58320c885ab7b2ee0d0b5813a697268bd2494a06de792790b13668c08
raw: Object
- raw transaction's data with fields encoded as strings
Additional modules
Those are optional:
import * as formatters from 'micro-eth-signer/formatters';
import { validateField, validateFields } from 'micro-eth-signer/tx-validator'
// formatters:
export function parseDecimal(s: string, precision: number): bigint;
export function formatDecimal(n: bigint, precision: number): string;
export function perCentDecimal(precision: number, price: number): bigint;
export function roundDecimal(n: bigint, roundPrecision: number, precision?: number, price?: number): bigint;
export function fromWei(wei: string | number | bigint): string;
export function formatUSD(amount: number): string;
Performance
Transaction signature matches noble-curves
sign()
speed, which means over 4000 times per second on ARM Mac.
The first call of sign
will take 20ms+ due to noble-curves secp256k1 utils.precompute
.
To run benchmarks, execute npm run bench
.
License
MIT License
Copyright (c) 2021 Paul Miller (https://paulmillr.com)