Foundry

Foundry is a blazing fast, portable and modular toolkit for Ethereum application development written in Rust.

Foundry consists of:

• Forge: Ethereum testing framework (like Truffle, Hardhat and Dapptools).
• Cast: Swiss army knife for interacting with EVM smart contracts, sending transactions and getting chain data.

Need help getting started with Foundry? Read the 📖 Foundry Book (WIP)!

Installation

Having issues? See the troubleshooting section.

First run the command below to get foundryup, the Foundry toolchain installer:

curl -L https://foundry.paradigm.xyz | bash

If you do not want to use the redirect, feel free to manually download the foundryup installation script from here.

Then, run foundryup in a new terminal session or after reloading your PATH.

Other ways to use foundryup, and other documentation, can be found here. Happy forging!

Installing from source

For people that want to install from source, you can do so like below:

git clone https://github.com/foundry-rs/foundry
cd foundry
cargo install --path ./cli --bins --locked --force

Or via cargo install --git https://github.com/foundry-rs/foundry --locked

Installing via Docker

Foundry maintains a Docker image repository.

You can pull the latest release image like so:

docker pull ghcr.io/foundry-rs/foundry:latest

For examples and guides on using this image, see the Docker section in the book.

Manual download

You can manually download nightly releases here.

Forge

Features

• Fast & flexible compilation pipeline
  • Automatic Solidity compiler version detection & installation (under ~/.svm)
  • Incremental compilation & caching: Only changed files are re-compiled
  • Parallel compilation
  • Non-standard directory structures support (e.g. Hardhat repos)
• Tests are written in Solidity (like in DappTools)
• Fast fuzz testing with shrinking of inputs & printing of counter-examples
• Fast remote RPC forking mode, leveraging Rust's async infrastructure like tokio
• Flexible debug logging
  • Dapptools-style, using DsTest's emitted logs
  • Hardhat-style, using the popular console.sol contract
• Portable (5-10MB) & easy to install without requiring Nix or any other package manager
• Fast CI with the Foundry GitHub action.

How Fast?

Forge is quite fast at both compiling (leveraging ethers-solc) and testing.

See the benchmarks below. More benchmarks can be found in the v0.2.0 announcement post and in the Convex Shutdown Simulation repository.

Testing Benchmarks

Project	Forge	DappTools	Speedup
maple-labs/loan	800ms	4m28s	335x
Rari-Capital/solmate	2.8s	6m34s	140x
reflexer-labs/geb	0.4s	23s	57.5x
Rari-Capital/vaults	0.28s	6.5s	23x

Note: In the above benchmarks, compilation was always skipped

Compilation Benchmarks

Takeaway: Forge compilation is consistently faster by a factor of 1.7-11.3x, depending on the amount of caching involved.

Cast

Cast is a swiss army knife for interacting with Ethereum applications from the command line.

More documentation can be found in the cast package.

Configuration

Using foundry.toml

Foundry is designed to be very configurable. You can configure Foundry using a file called foundry.toml in the root of your project, or any other parent director. See config package for all available options.

Configuration can be arbitrarily namespaced by profiles. The default profile is named default (see "Default Profile").

You can select another profile using the FOUNDRY_PROFILE environment variable. You can also override parts of your configuration using FOUNDRY_ or DAPP_ prefixed environment variables, like FOUNDRY_SRC.

forge init creates a basic, extendable foundry.toml file.

To see your current configuration, run forge config. To see only basic options (as set with forge init), run forge config --basic. This can be used to create a new foundry.toml file with forge config --basic > foundry.toml.

By default forge config shows the currently selected foundry profile and its values. It also accepts the same arguments as forge build.

DappTools Compatibility

You can re-use your .dapprc environment variabless by running source .dapprc beforehand using a Foundry tool.

Additional Configuration

You can find additional setup and configurations guides in the Foundry Book:

• Setting up VSCode
• Shell autocompletions

Troubleshooting Installation

libusb error when running forge/cast

If you are using the binaries as released, you may see the following error on MacOS:

dyld: Library not loaded: /usr/local/opt/libusb/lib/libusb-1.0.0.dylib

In order to fix this, you must install libusb like so:

brew install libusb

Out of date GLIBC error when running forge from default foundryup install:

If you run into an error resembling the following when using foundryup:

forge: /lib/x86_64-linux-gnu/libc.so.6: version 'GLIBC_2.29' not found (required by forge)

There are 2 workarounds:

1. Building from source: foundryup -b master
2. Using Docker

Contributing

See our contributing guidelines.

Getting Help

First, see if the answer to your question can be found in book, or in the relevant crate.

If the answer is not there:

• Join the support Telegram to get help, or
• Open a discussion with your question, or
• Open an issue with the bug

If you want to contribute, or follow along with contributor discussion, you can use our main telegram to chat with us about the development of Foundry!

Acknowledgements

• Foundry is a clean-room rewrite of the testing framework dapptools. None of this would have been possible without the DappHub team's work over the years.
• Matthias Seitz: Created ethers-solc which is the backbone of our compilation pipeline, as well as countless contributions to ethers, in particular the abigen macros.
• Rohit Narurkar: Created the Rust Solidity version manager svm-rs which we use to auto-detect and manage multiple Solidity versions.
• Brock Elmore: For extending the VM's cheatcodes and implementing structured call tracing, a critical feature for debugging smart contract calls.
• All the other contributors to the ethers-rs & foundry repositories and chatrooms.