# 3. Project Structure

Your project might look like this:&#x20;

`compound-comet-tutorial/`&#x20;

`├── package.json`&#x20;

`├── package-lock.json`&#x20;

`├── .env`&#x20;

`└── index.js`&#x20;

The index.js file will contain our code.



### Environment Variables

Create a .env file in your project folder to store your Sepolia RPC URL and private key safely (and don’t commit it to GitHub):

Example .env:

`SEPOLIA_RPC_URL="https://sepolia.infura.io/v3/YOUR_INFURA_PROJECT_ID"`

`PRIVATE_KEY="0xYOUR_SEPOLIA_PRIVATE_KEY"`

Replace:

• YOUR\_INFURA\_PROJECT\_ID with an actual Infura ID (or another Ethereum node provider).

&#x20;• 0xYOUR\_SEPOLIA\_PRIVATE\_KEY with your wallet’s private key that holds test ETH on Sepolia.
