Foundry Book

Chisel

Chisel is a fast, utilitarian, and verbose Solidity REPL.

The chisel binary can be used both within and outside of a Foundry project. If the binary is executed in a Foundry project root, Chisel will inherit the project’s configuration options.

Chisel is part of the Foundry suite and is installed alongside forge, cast, and anvil. If you haven’t installed Foundry yet, see Foundry installation.

Getting Started

To use Chisel, simply type chisel.

chisel

From here, start writing Solidity code! Chisel will offer verbose feedback on each input.

Create a variable a and query it:

➜ uint256 a = 123;
➜ a
Type: uint256
├ Hex: 0x7b
├ Hex (full word): 0x000000000000000000000000000000000000000000000000000000000000007b
└ Decimal: 123

Finally, run !source to see a was applied:

// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.28;

import {Vm} from "forge-std/Vm.sol";

contract REPL {
    Vm internal constant vm = Vm(address(uint160(uint256(keccak256("hevm cheat code")))));

    /// @notice REPL contract entry point
    function run() public {
        uint256 a = 123;
    }
}

To see available commands, type !help within the REPL.

📚 Reference

See the chisel Reference for in depth information on Chisel and its capabilities.