## Deployment Parameterization We're back to our code base. We now have this `get_price` function which we are actually going to comment out. Again, I'm using command forward slash as a keyboard shortcut for this because we are not actually going to use this. But what we are going to do is we're going to create this `get_eth_to_usd_rate` function. We just learned how to get the price from a chain price feed. This is really exciting. We're only going to use this one price feed in this entire contract. We are going to make the price feed a state variable, up at the top. Since our structs are the same as in the last lesson, the `AggregatorV3Interface` is a new type. We can create a variable, a state variable, or a storage variable, called `price_feed` of type `AggregatorV3Interface`. In our deploy function we can say `self.price_feed = AggregatorV3Interface()` at address. We are hardcoding this address into the contract. We can add a comment saying that we are using the Sepolia testnet: ```python # Sepolia ``` We should instead add the address as a parameter. We can do this with the following code: ```python @external def deploy(price_feed_address: address): self.minimum_usd = 5 self.price_feed = AggregatorV3Interface(price_feed_address) ``` The deploy function now has an input for the price feed address. Now that we have our `price_feed` object, we can scroll down to our `get_eth_to_usd_rate` function. We will make the price variable equal to `staticcall self.price_feed.latestAnswer()`. ```python @internal def get_eth_to_usd_rate(): price: int256 = staticcall(self.price_feed.latestAnswer()) ``` This way, right when we deploy our contract, we can parameterize the address that we want to use. This is a much cleverer way than hard coding it in.