Hardhat-gasless-deployer-example

This is a working example for gasless deployer hardhat plugin using the gas station network.

Install

yarn

Start local GSN

Start a new terminal to run your local GSN relayer (local network)

yarn gsn-with-ganache

You should see the following predeployed contracts address:

  RelayHub: 0xC89Ce4735882C9F0f0FE26686c53074E09B0D550
  RelayRegistrar: 0xe78A0F7E598Cc8b0Bb87894B0F60dD2a88d6a8Ab
  StakeManager: 0x5b1869D9A4C187F2EAa108f3062412ecf0526b24
  Penalizer: 0xCfEB869F69431e42cdB54A4F4f105C19C080A601
  Forwarder: 0x254dffcd3277C0b1660F6d42EFbB754edaBAbC2B
  TestToken (test only): 0x9b1f7F645351AF3631a656421eD2e40f2802E6c0
  Paymaster : 0xD833215cBcc3f914bD1C9ece3EE7BF8B14f841bb

Configure

Update the paymaster, relayer hub and forwarder contract addresses in hardhat-config.ts with the addresses produced from your local GSN (above):

hHGaslessDeployer: {
    ...
    paymaster: "0xD833215cBcc3f914bD1C9ece3EE7BF8B14f841bb",
    relayerHub: "0xC89Ce4735882C9F0f0FE26686c53074E09B0D550",
    forwarder: "0x254dffcd3277C0b1660F6d42EFbB754edaBAbC2B",
  },

Usage

Add your private key in hardhat-config.ts, this key will be used for signing transaction prior deployment.

    gsn: {
        url: "http://127.0.0.1:8545",
        accounts: [
            `YOUR_PRIVATE_KEY`,
        ],
        chainId: 1337
        },
    ...

Finally, deploy the sample Lock contract using the gasless deploy HardHat plugin.

yarn deploy:gsn

If this is the first time you run this plugin, it will deploy two helper contracts:

A factory contract: which holds generic deployment logic with CREATE2.
A paymaster contract: A whitelist paymaster but for simiplicity, the plugin will use a pre-deployed paymaster.

These contracts will be deployed only once and their data will be stored in gasless-contracts-deployments.json file.

{
  "gsn": {
    "factory": "0x6eD79Aa1c71FD7BdBC515EfdA3Bd4e26394435cC",
    "paymaster": "0xb09bCc172050fBd4562da8b229Cf3E45Dc3045A6"
  }
}

You should expect something as follows:

....
Transaction hash: 0x00000000a6d7ab10560d5ae6951daf77387b24ab2935ea06c05eaa3595dc78d1
Target contract "Lock" has been deployed @ "0x563013bCb323D720c4a282AA060552cCE3860c85"

Test

You can run yarn test to execute a simple test case for deploying Lock contract on the GSN local net.

The test case has to:

deploy the factory & whitlestPaymaster contracts
check the balance before deploying target contract Lock
deploy the target Lock contract
assert that the balance doesn't change after the deployment

Please do note that sometimes the deployment might fail because at some point the randomly generated salt for CREATE2 doesn't fulfill the keccak256 hashing requirements. This will be fixed later. However you can re-run the test and it should work again.

0x3bfc / hardhat-gasless-deployer-example