Foundry

​

Installing foundry

On your command line, run:

curl -L https://raw.githubusercontent.com/matter-labs/foundry-zksync/main/install-foundry-zksync | bash

You can find more information on the official zksync foundry website

​

Create a new project

forge init
forge build --zksync

This will create a new simple Foundry project with a Counter contract.

​

Set configs

Use the following configs on your foundry.toml

[etherscan]
testnet = { key = "${ETHERSCAN_API_KEY}", url = "${TESTNET_VERIFIER_URL}", chain = 531050104 } 
sophon = { key = "${ETHERSCAN_API_KEY}", url = "${MAINNET_VERIFIER_URL}", chain = 50104 } 

[rpc_endpoints]
testnet = "${TESTNET_RPC_URL}"
sophon = "${MAINNET_RPC_URL}"

Create an .env file and set these env vars:

PRIVATE_KEY= # your deloyer private key
ETHERSCAN_API_KEY= # your etherscan API key
PAYMASTER_ADDRESS= # Sophon's paymaster address

# sophon testnet
TESTNET_RPC_URL=https://rpc.testnet.sophon.xyz
TESTNET_VERIFIER_URL=https://api-explorer-verify.testnet.sophon.xyz/contract_verification
TESTNET_CHAIN_ID="531050104"

# sophon
MAINNET_RPC_URL=https://rpc.sophon.xyz
MAINNET_VERIFIER_URL=https://verification-explorer.sophon.xyz/contract_verification
MAINNET_CHAIN_ID="50104"

​

Counter contract deployment

​

Basic deployment

source .env && forge create ./src/Counter.sol:Counter --rpc-url testnet --private-key $PRIVATE_KEY --zksync

​

Deployment and verification

• Same as Basic deployment but you append the --verify flag
• Note that this will only verify on Sophscan

source .env && forge create ./src/Counter.sol:Counter --rpc-url testnet --private-key $PRIVATE_KEY --zksync --verify

​

Deployment using paymaster

• Same as Basic deployment but you append the --zk-paymaster-address flag
• Note that the paymaster allows you to perform gasless transactions, no need to have a SOPH balance

source .env && forge create ./src/Counter.sol:Counter --rpc-url testnet --private-key $PRIVATE_KEY --zksync --zk-paymaster-address $PAYMASTER_ADDRESS --zk-paymaster-input $(cast calldata "general(bytes)" "0x")

​

Deployment with paymaster and verification (all-in-one)

source .env && forge create ./src/Counter.sol:Counter --rpc-url testnet --private-key $PRIVATE_KEY --zksync --zk-paymaster-address $PAYMASTER_ADDRESS --zk-paymaster-input $(cast calldata "general(bytes)" "0x") --verify

​

Deploy contracts using foundry Scripts

​

Deployment using script

source .env && forge script ./script/Counter.s.sol --rpc-url testnet --private-key $PRIVATE_KEY --zksync --broadcast

​

Deployment using script and verification

• Same as Basic deployment using script but you append the --verify flag
• Note that this will only verify on Sophscan

source .env && forge create ./src/Counter.sol:Counter --rpc-url testnet --private-key $PRIVATE_KEY --zksync --verify

​

Deployment using script with paymaster

• Same as Basic deployment using script but you append the --zk-paymaster-address flag
• Note that this will only verify on Sophscan

To use the paymaster within a script you have 2 options: using a cheatcode or making a low-level call:

​

Using a foundry cheatcode

• Install forge-zksync-std library

• Use the vmExt.zkUsePaymaster cheatcode

• For simplicity, you can copy paste the following script:

  // SPDX-License-Identifier: UNLICENSED
  pragma solidity ^0.8.13;
  
  import {Script, console} from "forge-std/Script.sol";
  import {Counter} from "../src/Counter.sol";
  import {TestExt} from "lib/forge-zksync-std/src/TestExt.sol";
  
  contract CounterScript is Script, TestExt {
      Counter public counter;
  
      function setUp() public {}
  
      function run() public {
          vm.startBroadcast();
  
          // Encode paymaster input
          bytes memory paymaster_encoded_input = abi.encodeWithSelector(
              bytes4(keccak256("general(bytes)")),
              bytes("0x")
          );
          vmExt.zkUsePaymaster(vm.envAddress("PAYMASTER_ADDRESS"), paymaster_encoded_input);
          counter = new Counter();
  
          vm.stopBroadcast();
      }
  }
  

• You can now run the following command

  source .env && forge script ./script/Counter.s.sol --rpc-url testnet --private-key $PRIVATE_KEY --zksync --broadcast
  

​

Using a low-level call (in case you can’t install the cheatcode library)

• For simplicity, you can copy paste the following script (note that here we are using address(vm).call):

  // SPDX-License-Identifier: UNLICENSED
  pragma solidity ^0.8.13;
  
  import {Script, console} from "forge-std/Script.sol";
  import {Counter} from "../src/Counter.sol";
  import {TestExt} from "lib/forge-zksync-std/src/TestExt.sol";
  
  contract CounterScript is Script, TestExt {
      Counter public counter;
  
      function setUp() public {}
  
      function run() public {
          vm.startBroadcast();
  
          // Encode paymaster input
          bytes memory paymaster_encoded_input = abi.encodeWithSelector(
              bytes4(keccak256("general(bytes)")),
              bytes("0x")
          );
          (bool success, ) = address(vm).call(
              abi.encodeWithSignature(
                  "zkUsePaymaster(address,bytes)",
                  vm.envAddress("PAYMASTER_ADDRESS"),
                  paymaster_encoded_input
              )
          );
          require(success, "zkUsePaymaster() call failed");
          counter = new Counter();
  
          vm.stopBroadcast();
      }
  }
  
  

• You can now run the following command:

  source .env && forge script ./script/Counter.s.sol --rpc-url testnet --private-key $PRIVATE_KEY --zksync --broadcast
  

​

Deployment using script with paymaster and verification

• Same as Basic deployment using script with paymaster but you append the --verify flag
• Note that this will only verify on Sophscan

source .env && forge script ./script/Counter.s.sol --rpc-url testnet --private-key $PRIVATE_KEY --zksync --broadcast --verify

​

Contract verification

If you want to verify an already deployed contract, you can do so on Sophscan (an Etherscan-like explorer) and/or on Sophon’s Explorer.

• on Sophscan

source .env && forge verify-contract COUNTER_CONTRACT_ADDRESS ./src/Counter.sol:Counter:Counter --watch --rpc-url testnet --zksync

• on Sophon’s explorer

forge verify-contract COUNTER_CONTRACT_ADDRESS ./src/Counter.sol:Counter --watch --verifier zksync --verifier-url $TESTNET_VERIFIER_URL --zksync

with lib: forge build —zksync —libraries ./contracts/util/SignatureChecker.sol:SignatureChecker:0xb0A2cf27Bf984bd0c56dCFb37C9DA0F2c5028844

​

Contracts with constructor params

If your contracts receives constructor params, you can use the --constructor-args flag:

• Modify your Counter contract to receive a constructor param:

  // SPDX-License-Identifier: UNLICENSED
  pragma solidity ^0.8.13;
  
  contract Counter {
      uint256 public number;
  
      constructor(uint256 _number) {
          number = _number;
      }
  
      function setNumber(uint256 newNumber) public {
          number = newNumber;
      }
  
      function increment() public {
          number++;
      }
  }
  

• You can now run:

  forge create ./src/CounterWithConstructorParams.sol:Counter --rpc-url testnet --private-key $PRIVATE_KEY --zksync --constructor-args "$(cast abi-encode "constructor(uint256)" "123")"
  

• To verify or use paymaster, you can use the flags --verify and/or ----zk-paymaster-address as explained above.