Introduction to Starknet Contracts

1. Install starknet-foundry by running this command: curl -L https://raw.githubusercontent.com/foundry-rs/starknet-foundry/master/scripts/install.sh | sh

2. Restart your terminal run snfoundryup

3. Use this free RPC provider: https://free-rpc.nethermind.io/sepolia-juno/

4. Create an account contract by running this command on your terminal: sncast -u https://free-rpc.nethermind.io/sepolia-juno/ account create -n <name> --add-profile <profile_name>

5. Deploy the account contract: sncast --url https://free-rpc.nethermind.io/sepolia-juno account deploy --name <account_name>

NB Running the above command should trigger an error: error: Account balance is smaller than the transaction's max_fee. That why your account must be funded; to fund your account, visit - https://starknet-faucet.vercel.app/ and paste the account address that was generated on step 4 to request for testnet token.

6. Compile your contract by running: scarb build

Output

If you get an error like scarb: command not found, then it means you don't have scarb installed. To install scarb, run this command in your terminal curl --proto '=https' --tlsv1.2 -sSf https://docs.swmansion.com/scarb/install.sh | sh. You can checkout the full guide here

7. Declare your contract: sncast --account <your_account_name> --url https://free-rpc.nethermind.io/sepolia-juno/ declare --contract-name <contract_name>

   Example of a contract name is AggregatorContract

Output

8. Deploy your contract: sncast --account <your_account_name> --url https://free-rpc.nethermind.io/sepolia-juno/ deploy --class-hash <generated_class_hash>

Output

🥳🥳🥳 You have successfully deployed your first contract

Alternatively, you can create a snfoundry.toml with the following config:

[sncast.test_deploy_24]
account = "test_deploy_24"
accounts-file = "~/.starknet_accounts/starknet_open_zeppelin_accounts.json"
url = "https://free-rpc.nethermind.io/sepolia-juno/"

Using this approach simplifies interactions using sncast as you can simply run commands this command to declare a contract: sncast --profile <name_of_profile_on_snfoundry.toml> declare --contract-name <name_of_contract_to_be_deployed>

While deploying, make sure you check the constructor argument of the contract you are trying to deploy. All arguments must be passed in appropriately; for such case, use this command: sncast --profile <name_of_profile_on_snfoundry.toml> --class-hash <your_class_hash> --constructor-calldata <your_constructor_args>

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Introduction to Dispatchers

Deployed Contracts on Sepolia Testnet

OwnerContract

• class hash - 0x058d259a9c062f841b8658701afd553c8b51b7eb65cf1fea3e53cd33fc507a29
• address - 0x10643c1ad9f6effd8af79b32163977e803db69aae21444005044aeea85efc52

CounterContract

• class hash - 0x05f8ca4d37e05826fb90bd68d6ceff9ad3bd5a7ba51dfea46407f9f3aa723442
• address - 0x5afdb452821d219d5b8bc68a44ca3c6fa4dfc313150d30d093a279c090d69e3

Aggregator_Contract

• class hash - 0x381ae76764492a57d747cd651fbc19bf44152f185301b42686917377f4a85a5
• address - 0x2da68c5361610f7ec2366483926fe32160b217fa28e3ebc54cbe2f69fd51b90

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Interacting with Deployed Contracts

• Invoke: to execute the logic of a state-changing (writes) function within your deployed contracts from the terminal, run sncast --url https://free-rpc.nethermind.io/sepolia-juno/ --account <account_name> invoke --contract-address <your_contract_address> --function "<your_function_name>" --calldata <fn_args> If you have configured your snfoundry.toml file, run: sncast --profile <your_profile> invoke --contract-address <your_contract_address> --function "<your_function_name>" --calldata <fn_args>

• Call: to execute the logic of a non-state-changing (reads) function within your deployed contracts from the terminal, run: sncast --url https://free-rpc.nethermind.io/sepolia-juno/ --account <account_name> call --contract-address <your_contract_address> --function "<your_function_name"

NB:

To test out dispatchers, please call the address of the AggregatorContract which contains dispatchers to call the logic of Ownable and Counter contracts respectively. In the event the function to be called accepts some args, append the call --calldata flag to the above invoke and call commands with the appropriate args.

To compile your contract, run scarb build