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Contract Deployment Example

This is a quick tutorial to help you learn how to deploy a smart contract to the Boba network. We'll provide an example contract that allows you to store a single value and retrieve it.

Prerequisites​

Before you start, please make sure you have the following installed on your machine:

Then clone the Contract example repository to your environment; this will be the smart contract we work with in this tutorial.

Once you've prepared your environment, you're ready to get started!

Compile the Contract​

Compiling a contract for Boba is identical to compiling a contract for Ethereum mainchain. Notably, all standard solidity compiler versions can be used. For this contract, we will use 0.8.9.

Set the Config​

Checking the hardhat.config.ts file, you'll see some of the following configuration:

contract-example/hardhat.config.ts
networks: {
  boba_sepolia: {
    url: 'https://sepolia.boba.network',
      accounts: [process.env.DEPLOYER_PK],
  },
},
solidity: {
  version: '0.8.9',
    settings: {
    optimizer: {enabled: true, runs: 200},
  },
},
etherscan: {
  apiKey: {
      boba_sepolia: "boba", // not required, set placeholder
  },
  customChains: [
    {
      network: "boba_sepolia",
      chainId: 28882,
      urls: {
        apiURL: "https://api.routescan.io/v2/network/testnet/evm/28882/etherscan",
        browserURL: "https://testnet.bobascan.com"
      },
    },
  ],
}

...

Notice that process.env.DEPLOYER_PK. We need to set that variable with your own private key. Navigate to the .env file, and you'll find this:

contract-example/.env
DEPLOYER_PK=0xYOUR_PRIVATE_KEY_HERE

Replace "YOUR_PRIVATE_KEY_HERE" with your private key (and keep the preceding 0x).

Compile the Contract​

warning

This account must be funded, i.e. contain enough Sepolia ETH to cover the cost of the deployment.

With your config set, you can compile the contract with your choice of package manager by running the following:

yarn hardhat compile

You can verify that everything went well by looking for the build directory that contains your new JSON files. Now let's move on to testing!

Test the Contract​

We've set the JSON RPC provider for Boba Sepolia in the hardhat config file, so all we need to do next is run the test command:

yarn test

You should see a set of passing tests for your contract:

$ hardhat test test/contract.spec.ts --show-stack-traces
Using network 'boba_sepolia'.

Compiling your contracts...
===========================
> Everything is up to date, there is nothing to compile.

   your tests
Contract deployed at:  0x5FbDB2315678afecb367f032d93F642f64180aa3
    √ always succeeds
Contract deployed at:  0xe7f1725E7734CE288F8367e1Bb143E90bb3F0512
    √ contract deployed


  2 passing (3s)

✨  Done in 3s.

If so, congrats! You're ready to deploy an application to the Boba network.

Deploy the Contract​

Included in our provided example contract is the deployment file (contract-example/deploy/contract.deploy.ts, for the curious user). To use the file, run the following:

npx hardhat deploy --network boba_sepolia

After a few seconds your contract should deploy, and you should see this in your terminal:

yarn deploy
yarn run v1.22.15
hardhat deploy --network boba_sepolia

Compiling your contracts...
===========================
> Everything is up to date, there is nothing to compile.



Starting deployment scripts...
======================
> Network name:    'boba_sepolia'

contract.deploy.ts
==========================

   Deploying 'YourContract'
   -----------------
   > transaction hash:    0xe7cc5d048ffd426587b7d9c89aed4b0d7b2bd29c5532300bce8a9a57a4c4d689
   > Blocks: 0            Seconds: 0
   > contract address:    0xE769105D8bDC4Fb070dD3057c7e48BB98771dE15
   > block number:        6270
   > block timestamp:     1635787822
   > account:             0x21724227d169eAcBf216dE61EE7dc28F80CF8A92
   > balance:             0.901997296123301024
   > gas used:            855211 (0xd0cab)
   > gas price:           0.02 gwei
   > value sent:          0 ETH
   > total cost:          0.00001710422 ETH

   > Saving artifacts
   -------------------------------------
   > Total cost:       0.00001710422 ETH


Summary
=======
> Total deployments:   1
> Final cost:          0.00001710422 ETH


✨  Done in 10.11s.

Take note of the listed contract address in the output; we'll use it later.

Verify the Contract​

Using our tool Bobascan, you can verify the contract has been deployed and is valid.

In case you didn't catch your contract address from the deployment output text, you can find it (among many other things) with Bobascan. Sign in by connecting your crypto wallet to Bobascan, then navigate to your transactions. This will lead you to the contract address of your newly deployed contract. Copy this address, then replace "YOUR_CONTRACT_ADDRESS_HERE" with it in the command below to verify your contract:

npx hardhat verify --network boba_sepolia YOUR_CONTRACT_ADDRESS_HERE

You should see the following output once you've successfully verified your contract:

Nothing to compile
Successfully submitted source code for contract
contracts/YourContract.sol:YourContract at 0xFe0447Eecf08Eb16DfC5a3Fa2210B30dE3f2803d
for verification on the block explorer. Waiting for verification result...

Successfully verified contract YourContract on Etherscan.
https://testnet.bobascan.com/address/0xFe0447Eecf08Eb16DfC5a3Fa2210B30dE3f2803d#code

That's all it takes to deploy and verify your contract! This contract is simple enough (it stores and retrieves a single value) to get you started in using more complicated contracts. If you're feeling more ambitious, you can check one of our production-grade projects here.

Troubleshooting​

Example project not working? Create a Github Issue.