## Cross-Contract Interactions (Extcall) In this lesson, we are going to learn about interacting with other contracts. We begin with a Python script. ```python from src import favorites, favorites_factory from moccasin.boa.tools import VyperContract def deploy_favorites() -> VyperContract: favorites_contract: VyperContract = favorites.deploy() return favorites_contract def deploy_factory(favorites_contract: VyperContract): factory_contract: VyperContract = favorites_factory.deploy(favorites_contract_address) factory_contract.create_favorites(1) new_favorites_address: str = factory_contract.list_of_favorite_contracts(0) new_favorites_contract: VyperContract = favorites.at(new_favorites_address) print(f"Stored value is: {new_favorites_contract.retrieve()}") factory_contract.store_from_factory(0, 88) print(f"New contract stored value is: {new_favorites_contract.retrieve()}") print(f"Factory stored value is: {factory_contract.retrieve()}") def moccasin_main(): favorites_contract = deploy_favorites() deploy_factory(favorites_contract) moccasin_main() ``` We will run the code in a terminal. ```bash patrick@cu:mox-five-more-cu $ & mox run deploy Running run command... Stored value is: 77 New contract stored value is 88 Original contract stored value is 7 patrick@cu:mox-five-more-cu $ ``` We can use this to show how calling a function from a factory contract can affect the state of another contract. We can update the value of `favorites.vy` by calling the `store()` function from the `favorites_factory.vy` contract. We can also call `retrieve()` on the `favorites.vy` contract to see the stored value.