aws-kms-signer

An ethers.js and sequence.js-compatible signer using AWS Key Management Service keys.

Prerequisites

Set up AWS KMS

1. Create an AWS account if you don't have one
2. Go to AWS KMS in your AWS Console: https://console.aws.amazon.com/kms
3. Switch to your desired region (e.g., us-east-1)
4. Click "Create key"
5. Choose these settings:
   • Key type: Asymmetric
   • Key usage: Sign and verify
   • Key spec: ECC_SECG_P256K1 (This is crucial for Ethereum compatibility)
   • Alias: Give your key a name (e.g., eth-signer)
6. Configure key administrative permissions and key usage permissions as needed
7. Create the key

Get AWS Credentials

1. Go to AWS IAM Console: https://console.aws.amazon.com/iam
2. Create a new IAM user or select an existing one
3. Under "Security credentials", create new access keys
4. Save these values - you'll need them for environment variables:
   • AWS_ACCESS_KEY_ID
   • AWS_SECRET_ACCESS_KEY
   • AWS_REGION (the region where you created your key)
   • AWS_KMS_KEY_ID (the ARN of your key, looks like: arn:aws:kms:region:account:key/key-id)

Installation

npm install @0xsequence/aws-kms-signer
# or
yarn add @0xsequence/aws-kms-signer
# or
pnpm add @0xsequence/aws-kms-signer

Usage

Basic Setup

import { AwsKmsSigner } from 'aws-kms-signer'
import { KMSClient } from '@aws-sdk/client-kms'

const signer = new AwsKmsSigner(
  process.env.AWS_REGION,
  process.env.AWS_KMS_KEY_ID
)

Get Signer's Address

const address = await signer.getAddress()
console.log('Signer address:', address)

Sign a Message

const message = 'Hello World'
const signature = await signer.signMessage(message)
console.log('Signature:', signature)

Send a Transaction

const provider = new ethers.JsonRpcProvider('YOUR_RPC_URL')
const connectedSigner = signer.connect(provider)

const tx = {
  to: '0x...',
  value: 1
}

const response = await connectedSigner.sendTransaction(tx)
const receipt = await response.wait()
console.log('Transaction receipt:', receipt)

Sign Typed Data (EIP-712)

const domain = {
  name: 'My Dapp',
  version: '1',
  chainId: 1,
  verifyingContract: '0x...'
}

const types = {
  Person: [
    { name: 'name', type: 'string' },
    { name: 'wallet', type: 'address' }
  ]
}

const value = {
  name: 'John Doe',
  wallet: '0x...'
}

const signature = await signer.signTypedData(domain, types, value)

Use with Sequence Wallet

import { Session } from '@0xsequence/auth'
import { AwsKmsSigner } from 'aws-kms-signer'
import { KMSClient } from '@aws-sdk/client-kms'

const signer = new AwsKmsSigner(
  process.env.AWS_REGION,
  process.env.AWS_KMS_KEY_ID
)

const session = await Session.singleSigner({
  signer,
  projectAccessKey: 'YOUR_PROJECT_ACCESS_KEY'
})

const tx = {
  to: '0x...',
  value: 1
}

const chainId = 421614 //

const response = await session.account.sendTransaction(tx, chainId)
const receipt = await response.wait()
console.log('Transaction receipt:', receipt)

Development

Environment Setup

Create a .env file in the root directory:

AWS_REGION=
AWS_ACCESS_KEY_ID=
AWS_SECRET_ACCESS_KEY=
AWS_KMS_KEY_ID=
PROJECT_ACCESS_KEY=

Running Tests

# Install dependencies
pnpm install

# Run tests
pnpm test

License

MIT