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Supersim fork mode to simulate and interact with the state of the chain without needing to re-deploy or modify the contracts. This is possible if you’re relying on contracts already deployed on testnet / mainnet chains.

How it works

The supersim fork command simplifies the process of forking multiple chains in the OP Stack ecosystem simultaneously. It determines the appropriate block heights for each chain and launches both the L1 and L2 chains based on these values. This allows you to locally fork any chain in a superchain network of the superchain registry, default mainnet versions.

Example startup logs

Configuration

Notes

Fork height

The fork height is determined by L1 block height (default latest). This is then used to derive the corresponding L2 block to start from.

Interoperability contracts

By default, interop contracts are not deployed on forked networks. To include them, run supersim with the --interop.enabled flag.

Next steps

  • Explore the Supersim included contracts being used to help replicate the OP Stack environment.
  • Learn how to deposit transactions with Supersim, using a much simpler approach that bypasses the derivation pipeline.