contracts-bedrock

Optimism Smart Contracts (Bedrock)

This package contains the smart contracts that compose the on-chain component of Optimism's upcoming Bedrock upgrade. We've tried to maintain 100% backwards compatibility with the existing system while also introducing new useful features. You can find detailed specifications for the contracts contained within this package here.

A style guide we follow for writing contracts can be found here.

Contracts Overview

Contracts deployed to L1

Name	Proxy Type	Description
L1CrossDomainMessenger	ResolvedDelegateProxy	High-level interface for sending messages to and receiving messages from Optimism
L1StandardBridge	L1ChugSplashProxy	Standardized system for transfering ERC20 tokens to/from Optimism
L2OutputOracle	Proxy	Stores commitments to the state of Optimism which can be used by contracts on L1 to access L2 state
OptimismPortal	Proxy	Low-level message passing interface
OptimismMintableERC20Factory	Proxy	Deploys standard OptimismMintableERC20 tokens that are compatible with either StandardBridge
ProxyAdmin	-	Contract that can upgrade L1 contracts

Contracts deployed to L2

Name	Proxy Type	Description
GasPriceOracle	Proxy	Stores L2 gas price configuration values
L1Block	Proxy	Stores L1 block context information (e.g., latest known L1 block hash)
L2CrossDomainMessenger	Proxy	High-level interface for sending messages to and receiving messages from L1
L2StandardBridge	Proxy	Standardized system for transferring ERC20 tokens to/from L1
L2ToL1MessagePasser	Proxy	Low-level message passing interface
SequencerFeeVault	Proxy	Vault for L2 transaction fees
OptimismMintableERC20Factory	Proxy	Deploys standard OptimismMintableERC20 tokens that are compatible with either StandardBridge
L2ProxyAdmin	-	Contract that can upgrade L2 contracts when sent a transaction from L1

Legacy and deprecated contracts

Name	Location	Proxy Type	Description
AddressManager	L1	-	Legacy upgrade mechanism (unused in Bedrock)
DeployerWhitelist	L2	Proxy	Legacy contract for managing allowed deployers (unused since EVM Equivalence upgrade)
L1BlockNumber	L2	Proxy	Legacy contract for accessing latest known L1 block number, replaced by L1Block

Installation

We export contract ABIs, contract source code, and contract deployment information for this package via npm:

npm install @eth-optimism/contracts-bedrock

Development

Dependencies

We work on this repository with a combination of Hardhat and Foundry.

1. Install Foundry by following the instructions located here. A specific version must be used.

   foundryup -C da2392e58bb8a7fefeba46b40c4df1afad8ccd22

2. Install node modules with yarn (v1) and Node.js (16+):

   yarn install

Build

yarn build

Tests

yarn test

Running Echidna tests

You must have Echidna installed.

Contracts targetted for Echidna testing are located in ./contracts/echidna Each target contract is tested with a separate yarn command, for example:

yarn echidna:aliasing

Deployment

Configuration

1. Create or modify a file <network-name>.ts inside of the deploy-config folder.
2. Fill out this file according to the deployConfigSpec located inside of the `hardhat.config.ts
3. Optionally: Run npx hardhat generate-deploy-config --network <network-name> to generate the associated JSON file. This is required if using op-chain-ops.

Execution

1. Copy .env.example into .env
2. Fill out the L1_RPC and PRIVATE_KEY_DEPLOYER environment variables in .env
3. Run npx hardhat deploy --network <network-name> to deploy the L1 contracts
4. Run npx hardhat etherscan-verify --network <network-name> --sleep to verify contracts on Etherscan

Tools

Layout Locking

We use a system called "layout locking" as a safety mechanism to prevent certain contract variables from being moved to different storage slots accidentally. To lock a contract variable, add it to the layout-lock.json file which has the following format:

{
  "MyContractName": {
    "myVariableName": {
      "slot": 1,
      "offset": 0,
      "length": 32
    }
  }
}

With the above config, the validate-spacers hardhat task will check that we have a contract called MyContractName, that the contract has a variable named myVariableName, and that the variable is in the correct position as defined in the lock file. You should add things to the layout-lock.json file when you want those variables to never change. Layout locking should be used in combination with diffing the .storage-layout file in CI.