Deploying Contracts on Abstract

Default: Foundry. Abstract uses the ZK Stack VM — contracts must be compiled with zksolc, not standard solc. For Hardhat, see references/hardhat.md. For EVM differences, see references/evm-differences.md.

Foundry Setup

1. Install foundry-zksync

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

Warning: This overwrites standard Foundry. Switch back with foundryup if needed.

2. Create project

forge init my-abstract-project && cd my-abstract-project

3. Configure foundry.toml

[profile.default]
src = 'src'
libs = ['lib']
fallback_oz = true
is_system = false
mode = "3"

[etherscan]
abstractTestnet = { chain = "11124", url = "https://api-sepolia.abscan.org/api", key = "${ABSCAN_API_KEY}" }
abstractMainnet = { chain = "2741", url = "https://api.abscan.org/api", key = "${ABSCAN_API_KEY}" }

4. Compile

forge build --zksync

Outputs to zkout/ (not out/).

Deploy

Store private key securely

cast wallet import myKeystore --interactive

Fund the deployer

• Testnet: Claim from faucets or bridge from Sepolia
• Mainnet: Bridge ETH via Abstract Bridge

Deploy + verify (testnet)

forge create src/Counter.sol:Counter \
  --account myKeystore \
  --rpc-url https://api.testnet.abs.xyz \
  --chain 11124 \
  --zksync \
  --verify \
  --verifier etherscan \
  --verifier-url https://api-sepolia.abscan.org/api \
  --etherscan-api-key ${ABSCAN_API_KEY}

Deploy + verify (mainnet)

forge create src/Counter.sol:Counter \
  --account myKeystore \
  --rpc-url https://api.mainnet.abs.xyz \
  --chain 2741 \
  --zksync \
  --verify \
  --verifier etherscan \
  --verifier-url https://api.abscan.org/api \
  --etherscan-api-key ${ABSCAN_API_KEY}

Constructor arguments

Append --constructor-args <arg1> <arg2> in the order defined in the constructor.

Verify an Existing Contract

forge verify-contract <address> src/Counter.sol:Counter \
  --chain 11124 \
  --etherscan-api-key ${ABSCAN_API_KEY} \
  --zksync

Use --chain 2741 for mainnet. Chain names (abstract-testnet, abstract) also work.

Testing

forge test --zksync

Fork testing against live networks:

forge test --zksync --fork-url https://api.testnet.abs.xyz

Local node:

anvil-zksync
forge test --zksync --fork-url http://localhost:8011

Cheatcode limitation: On Abstract's ZK VM, cheatcodes (vm.prank, vm.roll, etc.) only work at the root test level — not from within contracts being tested.

Decision: Foundry vs Hardhat

Scenario	Use
Solidity-first, fast iteration	Foundry (default)
TypeScript preference	Hardhat (references/hardhat.md)
Existing Hardhat project	Hardhat (references/hardhat.md)
Existing Foundry project	Foundry
Need JS plugin ecosystem	Hardhat (references/hardhat.md)

Gotchas

• All forge commands need --zksync — without it, you get standard EVM bytecode that won't run on Abstract
• foundryup-zksync overwrites standard Foundry — use foundryup to switch back
• Abscan API key required — get one from abscan.org; set via export ABSCAN_API_KEY=<key> or .env
• zkout/ not out/ — compiled artifacts go to a different directory
• Never commit private keys — use cast wallet import or environment variables