eth-signature-verifier

Minimal Ethereum signature verifier for EIP-712, EIP-191, and eth_sign. No ethers.js, no web3.js. Zero dependencies.

Install

1npm install eth-signature-verifier

Usage

1import { verifyMessage, verifyTypedData } from 'eth-signature-verifier'
2
3// EIP-191 or personal_sign
4verifyMessage(
5  '0x742d35Cc1C3c72AE4d5e4F0e3D1E3c7E5E8C1A2B',
6  'Hello World',
7  '0x...'
8)
9
10// EIP-712 typed data
11verifyTypedData(
12  '0x742d35Cc1C3c72AE4d5e4F0e3D1E3c7E5E8C1A2B',
13  '0x...',
14  { name: 'MyApp', version: '1', chainId: 1 },
15  { Message: [{ name: 'content', type: 'string' }] },
16  { content: 'Hello World' }
17)

Using with ethers or viem

This library accepts types from popular Ethereum libraries without requiring them as dependencies:

1import { verifyTypedData } from 'eth-signature-verifier'
2import type { TypedDataDomain } from 'ethers'
3import type { TypedData } from 'viem'
4
5// With ethers types
6const ethersDomain: TypedDataDomain = { /* ... */ }
7const ethersTypes = { /* ... */ }
8verifyTypedData(address, signature, ethersDomain, ethersTypes, value)
9
10// With viem types  
11const viemDomain = { /* ... */ }
12const viemTypes: TypedData = { /* ... */ }
13verifyTypedData(address, signature, viemDomain, viemTypes, value)

Note: Only TypeScript types are supported - no runtime dependencies are added to your bundle.

Why not ethers.js?

Most apps don't need 2MB+ of dependencies just to verify a signature. This library does one thing well:

• No bundler bloat
• Works in browser or server
• Ideal for serverless, bots, RPC gateways, and minimal dapps

Examples

Express Middleware

1import { verifyMessage } from 'eth-signature-verifier'
2
3const auth = (req, res, next) => {
4  const { address, message, signature } = req.headers
5  if (!verifyMessage(address, message, signature)) {
6    return res.status(401).json({ error: 'Invalid signature' })
7  }
8  req.user = { address }
9  next()
10}

MetaMask Verification

1const message = 'Sign to authenticate'
2const signature = await ethereum.request({
3  method: 'personal_sign',
4  params: [message, account]
5})
6
7const isValid = verifyMessage(account, message, signature)

EIP-712 Permit

1const domain = {
2  name: 'MyToken',
3  version: '1',
4  chainId: 1,
5  verifyingContract: '0x...'
6}
7
8const types = {
9  Permit: [
10    { name: 'owner', type: 'address' },
11    { name: 'spender', type: 'address' },
12    { name: 'value', type: 'uint256' },
13    { name: 'nonce', type: 'uint256' },
14    { name: 'deadline', type: 'uint256' }
15  ]
16}
17
18verifyTypedData(owner, signature, domain, types, permit)

API

verifyMessage(address, message, signature): boolean

Verifies a raw message signed via personal_sign or eth_sign.

verifyTypedData(address, signature, domain, types, value): boolean

Verifies EIP-712 structured data signatures. All parameters must match the original signed payload.

Returns false if the signature is invalid or mismatched.

Contributing

See CONTRIBUTING.md for setup and contribution flow.

License

MIT © Zak Cole