Declaring New Contracts

Starknet provides a distinction between contract class and instance. This is similar to the difference between writing the code of a class MyClass {} and creating a new instance of it let myInstance = MyClass() in object-oriented programming languages.

Declaring a contract is a necessary step to have your contract available on the network. Once a contract is declared, it then can be deployed and then interacted with.

For a detailed CLI description, see declare command reference.


General Example

📝 Note Building a contract before running declare is not required. Starknet Foundry sncast builds a contract during declaration under the hood using Scarb.

First make sure that you have created a Scarb.toml file for your contract (it should be present in project directory or one of its parent directories).

Then run:

$ sncast --account myuser \
    --url \ 
    declare \
    --contract-name SimpleBalance

command: declare
class_hash: 0x8448a68b5ea1affc45e3fd4b8b480ea36a51dc34e337a16d2567d32d0c6f8a
transaction_hash: 0x7ad0d6e449e33b6581a4bb8df866c0fce3919a5ee05a30840ba521dafee217f

📝 Note Contract name is a part after the mod keyword in your contract file. It may differ from package name defined in Scarb.toml file.

📝 Note In the above example we supply sncast with --account and --url flags. If snfoundry.toml is present, and has the properties set, values provided using these flags will override values from snfoundry.toml. Learn more about snfoundry.toml configuration here.

💡 Info Max fee will be automatically computed if --max-fee <MAX_FEE> is not passed.