## Project Setup We're back in our `mox-cu` folder. Let's do a little `ls` to see what we've built so far: ```bash ls ``` We're building up a nice little folder here filled with demo projects that we're using to level up our career. Let's go ahead and make the next folder. We'll do `mkdir` and name this new folder `mox-buy-me-a-coffee-cu`. ```bash mkdir mox-buy-me-a-coffee-cu ``` Then, we'll `cd` into that folder. ```bash cd mox-buy-me-a-coffee-cu ``` Now, we can open this folder in our code editor. We'll do `code .`. ```bash code . ``` We already know that we have `mox --help` and `mox` installed. We're going to initialize our new project using `mox init`. We want to use VS Code, so we'll pass in the flag `--vscode`, and we'll use a `pyproject` file, so we'll pass in the `--pyproject` flag as well: ```bash mox init --vscode --pyproject ``` Now, we'll delete the files that were created in this directory so we can start from a blank project. We can just right-click, then click "delete" and "move to trash". To get our starting code for this project, we'll use the code from the "Buy Me A Coffee" section in the Remix Fundamentals video. We'll go over to our GitHub repository, open `remix-buy-me-a-coffee-cu` and then open the `buy-me-a-coffee.vy` file. We're going to bring this code into our `mox-buy-me-a-coffee-cu` directory. We can copy it and paste it into a new file. We can right-click, select "New File", and name it `buy-me-a-coffee.vy`: ```python # pragma version ^0.4.1 """ @license MIT @title Buy Me A Coffee! @author You! @notice This contract is for creating a sample funding contract We'll learn a new way to do interfaces later... """ interface AggregatorV3Interface: def decimals() -> uint256: view def description() -> String[1000]: view def version() -> uint256: view def latestAnswer() -> int256: view # Constants & Immutables MINIMUM_USD: public(constant(uint256)) = wei_value(5, "ether") PRICE_FEED: public(immutable(AggregatorV3Interface)) = # 0x694AA1769357215DE4FAC081bf1f309c33Dc4536 sepolia OWNER: public(immutable(address)) = PRECISION: constant(uint256) = 1 * (10 ** 18) # Storage funders: public(DynArray[address, 1000]) funder_to_amount_funded: public(HashMap[address, uint256]) with constants: 262, 853 @deploy def init(price_feed: address): PRICE_FEED = AggregatorV3Interface(price_feed) OWNER = msg.sender @external @payable def fund(): """Allows users to send $ to this contract Have a minimum amount to send How do we convert the ETH amount to dollars amount? """ usd_value_of_eth: uint256 = self.get_eth_to_usd_rate(msg.value) assert usd_value_of_eth >= MINIMUM_USD, "You must spend more ETH!" self.funders.append(msg.sender) self.funder_to_amount_funded[msg.sender] += msg.value @external def withdraw(): """Take the money out of the contract, that people sent via the fund function. How do we make sure only we can pull the money out? """ assert msg.sender == OWNER, "Not the contract owner!" raw_call(OWNER, b"", value = self.balance) # send(OWNER, self.balance) # resetting for funder: address in self.funders: self.funder_to_amount_funded[funder] = 0 self.funders = [] @internal @view def _get_eth_to_usd_rate(eth_amount: uint256) -> uint256: """Chris sent us 0.01 ETH for us to buy a coffee Is that more or less than $5? """ price: int256 = staticcall(PRICE_FEED.latestAnswer()) eth_price: uint256 = convert(price, price * eth_amount) * (10 ** 10) eth_amount_in_usd: uint256 = (eth_price * eth_amount) // PRECISION return eth_amount_in_usd # 18 '0's, 18 decimal places @external @view def get_eth_to_usd_rate(eth_amount: uint256) -> uint256: return self._get_eth_to_usd_rate(eth_amount) @external @payable def default(): self.fund() ``` Now, we'll compile the code. We'll use `mox compile` to do that. ```bash mox compile ``` We have successfully compiled the contract.