foundry-rs/foundry

What it is

Foundry is a modular Rust toolkit for Ethereum application development. It bundles four command-line tools that cover the common smart-contract workflow:

• Forge — compile, test, fuzz, debug and deploy Solidity contracts (Forge docs).
• Cast — query chain data and send transactions from the terminal (Cast docs).
• Anvil — a local Ethereum node, including mainnet forking, for development and tests (Anvil docs).
• Chisel — a Solidity REPL for quick experiments (Chisel docs).

It is aimed at Solidity/Vyper developers and teams who prefer a command-line, Rust-based workflow over other Ethereum development frameworks. The project is dual-licensed under Apache-2.0 and MIT.

Install and first run

The README installs Foundry through the foundryup installer. On a shell with curl available:

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

The second command installs the toolchain; see the installation guide for platform details and alternatives.

Create and test a starter project:

forge init counter && cd counter
forge build
forge test

Query a live network with Cast, using a public RPC endpoint:

cast block-number --rpc-url https://eth.merkle.io
cast balance vitalik.eth --ether --rpc-url https://eth.merkle.io

Start a local chain that forks mainnet:

anvil --fork-url https://eth.merkle.io

Editor integration

With VS Code installed, run forge lsp inside a Solidity project and Forge opens the project in an Extension Development Host with its bundled Solidity extension; no separate Foundry checkout or extension build is required. For other editors, configure the language server command as forge lsp --stdio. The server reads foundry.toml, workspace folders, remappings and evm_version automatically. See the editor guide for setup.

Constraints and support

Foundry is distributed as command-line binaries installed by foundryup; commands such as cast and anvil require an RPC endpoint (the examples use https://eth.merkle.io). anvil --fork-url needs access to an archive-capable mainnet RPC. Development questions go to the Telegram chat, support to the support channel, and bugs to the issue tracker. The full documentation is at getfoundry.sh.

HotRepo's take

Foundry recorded a best position of 14 on the Rust daily list on 2026-11-06, adding 7 stars that day. That is a steady presence for a mature project rather than a sudden spike. The useful signal is its scope: Forge, Cast, Anvil and Chisel in one Rust codebase, with a newer built-in forge lsp editor integration, make it a broad CLI foundation for Ethereum contract work.