âś… Contract has been deploy with the address: 0x4fd22715e2fbde1234f857b32768d9766b3fa8e2369445f1067b3c7d71864c2
In this workshop, you will learn how to create a simple Starknet smart contract, implement public functions, and events, access external contracts, and use OpenZeppelin's Ownable contract.
After completing each step, run the associated script to verify it has been implemented correctly.
Use the Cairo book and the Starknet docs as a reference.
Clone this repository and choose whether you prefer using Docker to manage global dependencies or not in the following steps:
- Install
asdf
(instructions) - Install Scarb
2.6.5
viaasdf
(instructions) - Install Starknet Foundry
0.25.0
viaasdf
(instructions) - Install the Cairo 1.0 extension for VSCode (marketplace)
- Make sure Docker is installed and running
- Install the Dev Containers extension for VSCode (marketplace)
- Launch an instance of VSCode inside of the container by going to View -> Command Palette -> Dev Containers: Rebuild and Reopen in Container
Note: All the commands shown from this point on will assume that you are using the integrated terminal of a VSCode instance running inside the container. If you want to run the tests on a different terminal you'll need to use the command
docker compose run test
.
Switch to the step1
branch to enable the verification tests:
git checkout -b step1 origin/step1
Initialize the project structure within the cloned repository by using the Scarb
package manager and enable compilation of Starknet Contracts.
- When initializing the project with
Scarb
, name the package asworkshop
- Create a new Cairo file under the
src
directory namedcounter.cairo
, and add the following starting code:#[starknet::contract] mod counter_contract { #[storage] struct Storage {} }
- In the
lib.cairo
file remove the code and define thecounter
module
Note: Using any other name will disrupt upcoming steps.
When completed, build your project by running the following command:
scarb build
- Check out the
scarb init
command to initialize a project. In case you want to initialize the project with a specific name, you can use thescarb init --name PACKAGE_NAME
command. - Refer to the Cheat Sheet for essential
Scarb
commands - To enable Starknet Contract compilation:
- Target
starknet-contract
. - Specify the Cairo version in the
Scarb.toml
. - Learn more in the Starknet Contract Target documentation.
- Target
Switch to the step2
branch to enable the verification tests:
git checkout -b step2 origin/step2
Add snforge
as a dependency within your Scarb.toml
file to allow execution of tests with Starknet Foundry.
- In your
Scarb.toml
, declare thesnforge_std
package as your project dependency and enablecasm
contract class generation - In your
Scarb.toml
, define a script namedtest
to be able to runsnforge test
command - In your
Scarb.toml
, set youredition
to target2023_01
When completed, execute the test suite to verify you've met all the requirements for this section.
scarb test
- Specify the version of Starknet Foundry that the project currently uses
- Refer to the Starknet Foundry Documention for more information.
- Refer to the Scarb Running Scripts Documentation for more information.
edition = "2023_01"
is a configuration that targets a general version of Cairo prelude. Refer to the Prelude Documentation for more information.
Switch to the step3
branch to enable the verification tests:
git checkout -b step3 origin/step3
Implement the constructor function to initialize an input number and store a variable named counter
within the contract.
- Store a variable named
counter
asu32
type in theStorage
struct. - Implement the constructor function that initializes the
counter
variable with a given input value.
When completed, execute the test suite to verify you've met all the requirements for this section.
scarb test
- Storage variables are the most common way to interact with your contract storage. You can read more about it in Chapter 14 - Contract Storage.
- The constructor function is a special type of function that runs only once. You can read more about it in Chapter 14 - Constructor Function.
Switch to the step4
branch to enable the verification tests:
git checkout -b step4 origin/step4
Implement an interface for the contract which contains the get_counter()
function. This function should return the value of the stored counter
variable within the contract.
- Implement an interface for a function named
get_counter()
which returns the value of thecounter
variable. - The
get_counter()
function must be within the contract's interface namedICounter
.
Note: Any other given name to the contract's interface would break the test, be sure to have to correct name!
When completed, execute the test suite to verify you've met all the requirements for this section.
scarb test
- To create a contract interface, you will need to define a trait with the name
ICounter
(otherwise the tests will fail) and mark the trait with the[starknet::interface]
attribute. You can read more about it in Chapter 15 Interfaces. - The
get_counter()
function should only be able to read the state of the contract and not modify it. You can read more about it in Chapter 14 - View functions.
Switch to the step5
branch to enable the verification tests:
git checkout -b step5 origin/step5
Within the same interface created in the previous step, implement a function called increase_counter()
that can increment the current value of the counter
by 1
each time it is invoked.
- Implement a function named
increase_counter()
which increments thecounter
value by1
. - The
increase_counter()
function must be within the contract's interface namedICounter
.
When completed, execute the test suite to verify you've met all the requirements for this section.
scarb test
- The
increase_counter()
function should be able to modify the state of the contract (also called an external function) and update thecounter
value within theStorage
. You can read more about it in Chapter 14 - External Functions.
Switch to the step6
branch to enable the verification tests:
git checkout -b step6 origin/step6
Implement an event named CounterIncreased
that emits the current value of the counter
variable, every time the value is increased.
- Define a variant named
CounterIncreased
in theEvent
enum. - When defining the
counter
variable within theCounterIncrease
struct, mark it with the#[key]
attribute. - Emit the event in the
increase_counter()
function, once thecounter
value has been incremented.
When completed, execute the test suite to verify you've met all the requirements for this section.
scarb test
- Events are custom data structures that are emitted by a contract. More information about Events can be found in Chapter 14 - Contract Events.
- To emit an event, you can use the
self.emit()
function as show here.
Note: CHECKPOINT Reached ⛳️! Switch to the
step15-js
branch to get a deployment script based on starknet.js.git checkout -b step15-js origin/step15-js
Switch to the step7
branch to enable the verification tests:
git checkout -b step7 origin/step7
In this step, we will introduce an external smart contract that acts as a kill switch for a specific function. Your task is to add the external KillSwitch
contract as a dependency within your project.
Note: The
KillSwitch
contract can be found here.
- In your
Scarb.toml
file, declare thekill_switch
package as your project dependency under the[dependencies]
section. - In your
Scarb.toml
file, to allow compilation of external contracts for Starknet Foundry, add the following line under the[[target.starknet-contract]]
section.build-external-contracts = ["kill_switch::KillSwitch"]
When completed, execute the test suite to verify you've met all the requirements for this section.
scarb test
- Refer to the Scarb Managing Dependencies Documention for more information.
- Refer to the Compiling External Cotnract for more information.
Switch to the step8
branch to enable the verification tests:
git checkout -b step8 origin/step8
Initialize the KillSwitch
contract by storing the contract's address given as an input variable in the constructor function.
- Store a variable named
kill_switch
as typeContractAddress
. - Update the constructor function to initialize the
kill_switch
variable.
When completed, execute the test suite to verify you've met all the requirements for this section.
scarb test
- The task is similar to Step 3. Refer to it for more information.
Switch to the step9
branch to enable the verification tests:
git checkout -b step9 origin/step9
Implement the KillSwitch
mechanism in the increase_counter()
by calling the is_active()
function from the KillSwitch
contract.
- If the function
is_active()
from theKillSwitch
contract returnsfalse
, then allow theincrease_counter()
function to increment the value; otherwise, return without incrementing.
Note: Analyze the
KillSwitch
code to understand the interface and the contract structure from here.
When completed, execute the test suite to verify you've met all the requirements for this section.
scarb test
- You need to import the
Dispatcher
andDispatcherTrait
of theKillSwitch
contract. These dispatchers are automatically created and exported by the compiler. More information about Contract Dispatcher can be found in Chapter 12.5.2 - Contract Dispatcher. - You can access the
is_active()
function from yourKillSwitch
contract dispatcher. - You can use an
if
expression to implement the mechanism. Refer to the Cairo Book to learn more.
Note: If you want to deploy the
Counter
contract, you can use the following deployedKillSwitch
contract address.Contract Address:
0x05f7151ea24624e12dde7e1307f9048073196644aa54d74a9c579a257214b542
Switch to the step10
branch to enable the verification tests:
git checkout -b step10 origin/step10
Protect the increase_counter()
function by reverting the transaction if KillSwitch
mechanism is enabled.
- Create the condition to revert the transaction if the
KillSwith
contract is enabled - Revert the transaction with the following message
Kill Switch is active
When completed, execute the test suite to verify you've met all the requirements for this section.
scarb test
- You can stop and revert a transaction with an error message using the
assert!()
macro. Refer to the Cairo Book documentation to learn more. - You can replace the
if
expression with theassert!()
macro instead.
Switch to the step11
branch to enable the verification tests:
git checkout -b step11 origin/step11
Add the external OpenZeppelin
contracts as a dependency within your project.
Note: The
OpenZeppelin
contracts can be found here.
- In your
Scarb.toml
file, declare theopenzeppelin
package as your project dependency under the[dependencies]
section.
When completed, execute the test suite to verify you've met all the requirements for this section.
$ scarb test
- Specify the OpenZeppelin
tag
version asv0.14.0
inScarb.toml
. - Refer to the OZ Contracts for Cairo Documention for more information.
Switch to the step12
branch to enable the verification tests:
git checkout -b step12 origin/step12
Initialize the Ownable
component from the OpenZeppelin contracts.
Before working on this step, make sure to read Chapter 16.2: Composability and Components and see how Components work.
- Declare the component inside your contract using the
component!()
macro. - Add the path to the component's storage and events to the contract's
Storage
andEvent
. - Embed the component's logic into your contract by creating an instance of the component's generic implementation with a specific
ContractState
.
When completed, execute the test suite to verify you've met all the requirements for this section.
scarb test
- Refer to the Using Components Inside a Contract documentation to learn how to implement a component within a contract.
Switch to the step13
branch to enable the verification tests:
git checkout -b step13 origin/step13
Modify the constructor function to call the initializer()
function within the Ownable
component to initialize the owner.
- The input variable of the constructor function should be named
initial_owner
When completed, execute the test suite to verify you've met all the requirements for this section.
scarb test
- To call the
initializer()
function you can look at what functionsself.ownable
exposes. - Refer to the Ownable Component to learn more about the accessible function.
Switch to the step14
branch to enable the verification tests
:
git checkout -b step14 origin/step14
Protect the increase_counter()
function so that only the owner of the contract can call this.
- Use the
assert_only_owner()
function from the Ownable Component.
When completed, execute the test suite to verify you've met all the requirements for this section.
scarb test
- To call the
assert_only_owner()
function you can look at what functionsself.ownable
exposes. - Check out the
assert_only_owner()
function from the Ownable Component for more information.
Switch to the step15-js
branch to get a deployment script based on starknet.js
.
git checkout -b step15-js origin/step15-js
To deploy your account contract to Starknet's testnet using the deploy.ts
script found in the scripts
folder.
Run the command below from the project's root folder to install the deployment script dependencies.
npm install
Create a wallet that the script can use to pay for the declaration of your account contract.
- Create a wallet on Starknet testnet using the Argent X or Braavos browser extension.
- Fund the wallet by using the Faucet or the Bridge.
- Create a file in the project's root folder called
.env
- Export the private key of the funded wallet and paste it into the
.env
file using the keyDEPLOYER_PRIVATE_KEY
.
DEPLOYER_PRIVATE_KEY=<YOUR_FUNDED_TESTNET_WALLET_PRIVATE_KEY>
- Export the public key of the funded wallet and paste it into the
.env
file using the keyDEPLOYER_ADDRESS
DEPLOYER_ADDRESS=<YOUR_FUNDED_TESTNET_WALLET_PUBLIC_ADDRESS>
To successfully deploy the contract with the script on the Starknet Testnet, you will need to provide an RPC URL. For our workshop, we will use Blast's Public RPC Endpoint.
Add the following line in your .env
file:
RPC_ENDPOINT=https://starknet-sepolia.public.blastapi.io/rpc/v0_7
Refer to Blast to learn more about their Starknet RPC Endpoints.
Run the script that will declare and deploy your smart contract on the Starknet Testnet and ensure that you adjust the constructor inputs in your deploy.ts
file appropriately.
Note: If you are deploying the smart contract from the CHECKPOINT, in the
deploy.ts
file, you will only need theinitial_counter
in theconstructor
variable. Ensure that you remove or comment out thekill_switch_address
andinitial_onwer
variables.Additionally, ensure that the variable names in the
deploy.ts
constructor are the same as in thecounter.cairo
constructor function.
const constructor = myCallData.compile("constructor", {
initial_counter: 100,
address: "0x05f7151ea24624e12dde7e1307f9048073196644aa54d74a9c579a257214b542",
initial_owner: process.env.DEPLOYER_ADDRESS,
});
- From the project's root folder run
npm run deploy
- Follow the instructions from the terminal
If the script finishes successfully your smart contract is ready to be used on Starknet testnet. Congratulations!