Hardhat KMS Signer

This plugin signs Ethereum transaction using KMS key during deployments or running HardHat scripts.

This is a fork with additional support for:

• function calls
• personal signs
• getting the public key
• signing transactions
• updated dependencies

Usage

It's assumed that you have AWS access configured and your role perform kms:sign using KMS key.

In hardhat.config.ts do:

import "hardhat-signer-kms";

const config: HardhatUserConfig = {
  networks: {
    sepolia: {
      url: `https://sepolia.infura.io/v3/${process.env.INFURA_KEY}`,
      kmsKeyId: "YOUR KMS KEY ID"
    }
  }
}

Learn your address

$ node_modules/.bin/hardhat console --network sepolia
Creating Typechain artifacts in directory types for target ethers-v5
Successfully generated Typechain artifacts!
Welcome to Node.js v12.22.6.
> getNamedAccounts().then(console.log)
Promise { <pending> }
> { deployer: '0x541dD0eC22fB1213d2C2B1fc83B5F302cEFF79A2' }

Remember to fund your address with some ETH before deploying.

Minimal EIP1559 gas values

On less crowded networks (such as Sepolia) there may be situations where automatic gas provider will set maxFeePerGas & maxPriorityFeePerGas near 0 (when empty blocks are mined). To prevent this you can set minimal values for them in config:

import "hardhat-signer-kms";

const config: HardhatUserConfig = {
  networks: {
    sepolia: {
      url: `https://sepolia.infura.io/v3/${process.env.INFURA_KEY}`,
      kmsKeyId: "YOUR KMS KEY ID",
      minMaxFeePerGas: 1600000000,
      mixMaxPriorityFeePerGas: 1200000000
    }
  }
}