Contract Deployment Tutorial

Scroll Alpha Testnet is now deprecated.

Please visit our new documentation for the Scroll Sepolia Testnet at https://docs.scroll.io/

Our Alpha Testnet allows the community to deploy smart contracts on Scroll. In this tutorial, we will teach you how to deploy a contract on the Scroll Testnet. This demo repo illustrates contract deployment with Hardhat and Foundry.

Note: Before you start deploying the contract, you need to request test tokens from a Goerli faucet and use the bridge to transfer some testETHfrom Goerli to Scroll Alpha.

Deploy contracts with Hardhat

1. If you haven't already, install nodejs and yarn.

2. Clone the repo and install dependencies

git clone https://github.com/scroll-tech/scroll-guides.git
cd scroll-guides/contract-deploy-demo
yarn install

3. Create a .env file following the example .env.example in the root directory. Change PRIVATE_KEY to your own account private key in the .env.

4. Run yarn compile to compile the contract.

5. Run yarn deploy:scrollTestnet to deploy the contract on the Scroll Alpha Testnet.

6. Run yarn test for hardhat tests.

Deploy contracts with Foundry

1. Clone the repo.

git clone https://github.com/scroll-tech/scroll-guides.git
cd scroll-guides/contract-deploy-demo

2. Install Foundry.

curl -L https://foundry.paradigm.xyz | bash
foundryup

3. Run forge build to build the project.

4. Deploy your contract with Foundry

forge create --rpc-url https://alpha-rpc.scroll.io/l2 \
  --value <lock_amount> \
  --constructor-args <unlock_time> \
  --private-key <your_private_key> \
  --legacy \
  contracts/Lock.sol:Lock

• <lock_amount> is the amount of test ETH to be locked in the contract. Try setting this to some small amount, like 0.0000001ether.

• <unlock_time> is the Unix timestamp after which the funds locked in the contract will become available for withdrawal. Try setting this to some Unix timestamp in the future, like 1696118400 (this Unix timestamp corresponds to October 1, 2023).

For example:

forge create --rpc-url https://alpha-rpc.scroll.io/l2 \
  --value 0.00000000002ether \
  --constructor-args 1696118400 \
  --private-key 0xabc123abc123abc123abc123abc123abc123abc123abc123abc123abc123abc1 \
  --legacy contracts/Lock.sol:Lock

Questions and Feedback

Thank you for participating in and developing on the Scroll Alpha Testnet. If you encounter any issues, join our Discord and ask us in the developers channels.

Developer Notes

1. The SELFDESTRUCT opcode is disabled and will not be supported in Scroll, as it is slated to be removed from the EVM at a later date.

2. For now, we have set Layer 2 gas prices to be the same as on Ethereum Layer 1. However, these gas prices are subject to change and will be set in the future to match proving costs. We will endeavor to minimize these changes, primarily applying them to ZK-unfriendly precompiles when necessary for security.

3. For now, we recommend using london as a target EVM version for compiling. You can read more on that in the Ethereum & Alpha Testnet differences section.

4. CREATE and CREATE2 opcodes will yield the same behaviour as on Ethereum mainnet. Computation and address calculation is done in the same manner as on Ethereum.