Supersim is a lightweight tool to simulate the Superchain locally (with a single L1 and multiple OP-Stack L2s).
- spin up multiple anvil nodes
- predeployed OP Stack contracts and useful mock contracts (ERC20)
- fork multiple remote chains (fork the entire Superchain)
- simulate L1 <> L2 message passing (deposits) and L2 <> L2 message passing (interoperability)
For detailed instructions and usage guides, refer to the 📚 Supersim docs.
supersim
requires anvil
to be installed.
Follow this guide to install Foundry.
brew install ethereum-optimism/tap/supersim
Download the executable for your platform from the GitHub releases page.
supersim
Vanilla mode will start 3 chains, with the OP Stack contracts already deployed.
Chain Configuration
-----------------------
L1: Name: Local ChainID: 900 RPC: http://127.0.0.1:8545 LogPath: /var/folders/y6/bkjdghqx1sn_3ypk1n0zy3040000gn/T/anvil-chain-900-3719464405
L2s: Predeploy Contracts Spec ( https://specs.optimism.io/protocol/predeploys.html )
* Name: OPChainA ChainID: 901 RPC: http://127.0.0.1:9545 LogPath: /var/folders/y6/bkjdghqx1sn_3ypk1n0zy3040000gn/T/anvil-chain-901-1956365912
L1 Contracts:
- OptimismPortal: 0xF5fe61a258CeBb54CCe428F76cdeD04Cbc12F53d
- L1CrossDomainMessenger: 0xe5bda89cd85cE0DfB80E053281cA070D65B738e6
- L1StandardBridge: 0xa01ae68902e205B420FD164435F299E07b0C778b
* Name: OPChainB ChainID: 902 RPC: http://127.0.0.1:9546 LogPath: /var/folders/y6/bkjdghqx1sn_3ypk1n0zy3040000gn/T/anvil-chain-902-1214175152
L1 Contracts:
- OptimismPortal: 0xdfC9DEAbEEbDaa7620C71e2E76AEda32919DE5f2
- L1CrossDomainMessenger: 0xCB9768921831677Ae15cE4B64A10B94F49cD88E2
- L1StandardBridge: 0x2D8543c236a4d626f54B51Fa8bc229a257C5143E
Some examples below!
To simplify the process, you can now run Supersim using Docker. This approach ensures a consistent development environment without needing to install dependencies on your local machine. Here are the steps:
docker build -t supersim .
docker run --rm -it --network host supersim:latest
This setup encapsulates Supersim in a container, isolating it from the host system. This ensures a clean, conflict-free environment and provides an added layer of security by reducing the application's permissions on the host.
Some examples below!
1. Check initial balance on the L2 (chain 901)
Grab the balance of the sender account on L2:
cast balance 0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266 --rpc-url http://127.0.0.1:9545
2. Call bridgeETH
function on the L1StandardBridgeProxy
contract on the L1 (chain 900)
Initiate a bridge transaction on the L1:
cast send 0xa01ae68902e205B420FD164435F299E07b0C778b "bridgeETH(uint32 _minGasLimit, bytes calldata _extraData)" 50000 0x --value 0.1ether --rpc-url http://127.0.0.1:8545 --private-key 0xac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80
3. Check the balance on the L2 (chain 901)
Verify that the ETH balance of the sender has increased on the L2:
cast balance 0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266 --rpc-url http://127.0.0.1:9545
In a typical L2 to L2 cross-chain transfer, two transactions are required:
- Send transaction on the source chain – This initiates the token transfer on Chain 901.
- Relay message transaction on the destination chain – This relays the transfer details to Chain 902.
To simplify this process, you can use the --interop.autorelay
flag. This flag automatically triggers the relay message transaction once the initial send transaction is completed on the source chain, improving the developer experience by removing the need to manually send the relay message.
1. Start supersim
with the autorelayer enabled.
supersim --interop.autorelay
2. Mint tokens to transfer on chain 901
Run the following command to mint 1000 L2NativeSuperchainERC20
tokens to the recipient address:
cast send 0x420beeF000000000000000000000000000000001 "mint(address _to, uint256 _amount)" 0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266 1000 --rpc-url http://127.0.0.1:9545 --private-key 0xac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80
3. Initiate the send transaction on chain 901
Send the tokens from Chain 901 to Chain 902 using the following command:
cast send 0x420beeF000000000000000000000000000000001 "sendERC20(address _to, uint256 _amount, uint256 _chainId)" 0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266 1000 902 --rpc-url http://127.0.0.1:9545 --private-key 0xac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80
4. Wait for the relayed message to appear on chain 902
In a few seconds, you should see the RelayedMessage on chain 902:
# example
INFO [08-30|14:30:14.698] L2ToL2CrossChainMessenger#RelayedMessage sourceChainID=901 destinationChainID=902 nonce=0 sender=0x420beeF000000000000000000000000000000001 target=0x420beeF000000000000000000000000000000001
5. Check the balance on chain 902
Verify that the balance of the L2NativeSuperchainERC20 on chain 902 has increased:
cast balance --erc20 0x420beeF000000000000000000000000000000001 0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266 --rpc-url http://127.0.0.1:9546
For more detailed instructions and usage guides, refer to the 📚 Supersim docs.
If you're relying on contracts already deployed on testnet / mainnet chains, use fork mode to simulate and interact with the state of the chain without needing to re-deploy or modify the contracts.
Locally fork any of the available chains in a superchain network of the superchain registry, default mainnet
versions.
supersim fork --chains=op,base,zora
The fork height is determined by L1 block height (default latest
), which determines the maximum timestamp for the forked L2 state of each chain.
Chain Configuration
-----------------------
L1: Name: mainnet ChainID: 1 RPC: http://127.0.0.1:8545 LogPath: /var/folders/y6/bkjdghqx1sn_3ypk1n0zy3040000gn/T/anvil-chain-1-832151416
L2s: Predeploy Contracts Spec ( https://specs.optimism.io/protocol/predeploys.html )
* Name: op ChainID: 10 RPC: http://127.0.0.1:9545 LogPath: /var/folders/y6/bkjdghqx1sn_3ypk1n0zy3040000gn/T/anvil-chain-10-2710239022
L1 Contracts:
- OptimismPortal: 0xbEb5Fc579115071764c7423A4f12eDde41f106Ed
- L1CrossDomainMessenger: 0x25ace71c97B33Cc4729CF772ae268934F7ab5fA1
- L1StandardBridge: 0x99C9fc46f92E8a1c0deC1b1747d010903E884bE1
* Name: base ChainID: 8453 RPC: http://127.0.0.1:9546 LogPath: /var/folders/y6/bkjdghqx1sn_3ypk1n0zy3040000gn/T/anvil-chain-8453-1054019892
L1 Contracts:
- OptimismPortal: 0x49048044D57e1C92A77f79988d21Fa8fAF74E97e
- L1CrossDomainMessenger: 0x866E82a600A1414e583f7F13623F1aC5d58b0Afa
- L1StandardBridge: 0x3154Cf16ccdb4C6d922629664174b904d80F2C35
* Name: zora ChainID: 7777777 RPC: http://127.0.0.1:9547 LogPath: /var/folders/y6/bkjdghqx1sn_3ypk1n0zy3040000gn/T/anvil-chain-7777777-1949580962
L1 Contracts:
- OptimismPortal: 0x1a0ad011913A150f69f6A19DF447A0CfD9551054
- L1CrossDomainMessenger: 0xdC40a14d9abd6F410226f1E6de71aE03441ca506
- L1StandardBridge: 0x3e2Ea9B92B7E48A52296fD261dc26fd995284631
go run cmd/main.go
- build the binary by running:
go build cmd/main.go
- start supersim in vanilla mode by running:
./main
By default, interop contracts are not deployed on forked networks. To include them, run supersim with the --interop.enabled
flag
supersim fork --chains=op,base,zora --interop.enabled
While existing tools focus on isolated smart contract testing, Supersim provides a local development environment that mirrors the complex interactions of the Superchain ecosystem. Simulate entire cross-chain application flows, complete with deployed contracts, intricate message passing infrastructure, and OP-Stack specific logic with one command.
Multichain development offers unique challenges:
- Coordinating startup and running multiple local chains
- Deploying system contracts to mimic desired functionality
- Running local offchain services like message relayers
Supersim enables fast, local iteration on cross-chain features, with a simple developer interface.
Contributions are encouraged, but please open an issue before making any major changes to ensure your changes will be accepted.
See CONTRIBUTING.md for contributing information.
Files are licensed under the MIT license.