sim:fork

Fork the blockchain and execute commands in a simulation.

Syntax

sim:fork <block>

Arguments

Name	Type	Description
block	block	Commands to execute in the fork

Options

Name	Type	Description
--block-number	number	Block number to fork from
--from	address	Default sender address
--auth-token	string	RPC provider authentication token
--using	simulation-mode	Simulation backend (anvil, hardhat, tenderly, ethereumjs)

Examples

# Fork and set account balance
sim:fork --using anvil (
  sim:set-balance @me 100e18
)

Notes

• Supported backends: anvil, hardhat, tenderly, ethereumjs (default)
• The ethereumjs backend runs entirely in the browser — no external node needed
• All commands inside the fork block execute against the simulated state
• Changes do not affect the real chain
• batch (...) inside a fork simulates an EIP-7702 batch: if the sender EOA has no delegation yet, the fork installs a delegation to MetaMask’s EIP7702StatelessDeleGator (0x63c0c19a282a1B52b07dD5a65b58948A07DAE32B) and executes all batched calls atomically in a single self-call transaction. An existing delegation on the EOA is reused as-is.

See Also

• set-balance — set account ETH balances
• expect — assert conditions
• wait — advance time