Foundry is a free, open source toolkit for developers who build smart contracts on Ethereum and other EVM-compatible networks. It is aimed at Solidity programmers who want to write, test and deploy contracts from the terminal instead of stitching together several separate tools. On Windows, the program installs with a single command through Scoop, a command-line package manager.
The project is actively maintained. The latest version is 1.8.7, and the most recent code update landed in October 2026. Foundry is released under the MIT or Apache-2.0 license, so the source code is open for reading, modification and reuse. Below you will find what the toolkit includes, how to install it, and where it fits among other tools for Web3 development.
What Is Foundry and Who Is It For?
Foundry is not a single application but a set of command-line tools that cover different parts of the smart contract workflow. Its audience is developers who write contracts in Solidity and want their build, test and deployment steps to live in scripts rather than in mouse clicks. A freelance developer building a token contract, a small team preparing a DeFi prototype, or a student learning how the EVM handles storage can all use the same toolkit.
The typical starting point is a new project. You create a folder structure, write contracts, and add tests that describe the behavior you expect. Because the tests run in the same environment as the code, you can rerun them after every change and catch regressions early. Teams often keep these tests in version control so anyone on the project can run them.
Foundry also suits people who already work in a terminal. If you use Git, shell scripts and continuous integration pipelines, the tools will feel familiar. If you prefer a visual editor with buttons for every action, a graphical environment may feel more comfortable, which is one reason developers sometimes pair Foundry with a separate editor.
From Idea to Live Contract: The Development Lifecycle
Every Ethereum contract follows a similar path. First, the developer writes the logic in Solidity, the language used for most contracts on the EVM. Next, the source code is compiled into bytecode that the network can execute. Then comes testing, which is where much of the time gets spent. Tests check ordinary cases, edge cases and unusual inputs that a user might never try by hand.
After tests pass, many teams run the contract against a local chain or a public test network. This step reveals problems that only appear when the contract interacts with other contracts or with realistic transaction traffic. Only then does deployment happen, often followed by verification of the source code so that others can read it on a block explorer.
Each stage has a cost. Deploying to Ethereum requires paying gas, the fee paid to the network for computation and storage. Gas costs change with network conditions, so a contract that is cheap to deploy today may cost more later. Building the habit of estimating gas during testing prevents unpleasant surprises when the contract finally goes live.
Key Terms for Smart Contract Developers
New developers often meet a set of terms that appear throughout Foundry's documentation and community discussions. Understanding them makes the tools easier to use.
- EVM (Ethereum Virtual Machine): the runtime that executes smart contract code on Ethereum and compatible networks.
- Gas: the unit that measures computational work, and the fee users pay for it.
- Testnet: a public network that behaves like the main network but uses tokens without real value, useful for trial deployments.
- RPC endpoint: the address a tool uses to send requests to a node.
- Fuzz testing: running a function with many generated inputs to find cases the developer did not anticipate.
- REPL: a read-eval-print loop, an interactive prompt where you type code and see the result immediately.
Knowing these terms helps you read error messages and documentation without guessing. Many problems that look mysterious, such as a failed transaction, turn out to be a gas limit issue or a wrong endpoint address.
Key features
Forge for Building and Testing Contracts
Cast for Interacting With Chains
Anvil for Local Testing
Chisel for Solidity Experiments
Supported coins
The toolkit is built around Ethereum (ETH), the network named in its documentation. Because Cast and Anvil operate on EVM smart contracts, the same workflow generally carries over to other EVM-compatible chains, though you should confirm each chain's settings before you deploy.
How to install Foundry on Windows
PS> scoop install foundry- 1
Open PowerShell
Launch Windows PowerShell or Windows Terminal. All commands in this section are typed at the prompt, so keep the window open until the installation finishes.
- 2
Make Sure Scoop Is Installed
Foundry is distributed for Windows through Scoop. If you do not have it yet, install Scoop first by following its official instructions, then reopen the terminal so the scoop command is available.
- 3
Install Foundry
Run scoop install foundry. Scoop downloads the package, checks it against the hash recorded in its manifest, and makes the forge, cast, anvil and chisel executables available from any new terminal.
- 4
Manual Installation Option
If you prefer not to use a package manager, download only from the official website at getfoundry.sh or from the GitHub Releases page of the foundry-rs project. Verify the SHA-256 checksum published with the release before running the file, then place the executables in a folder listed in your PATH.
-
Confirm the Installation
Open a new terminal and run forge, cast, anvil and chisel with the --version flag. If each tool prints a version number, the toolkit is ready to use.
How to use Foundry
Once Foundry is installed, the usual workflow starts with a new project and moves through building, testing and interacting with a local chain. The steps below follow that order and assume basic familiarity with Solidity.
- Create a project. Run forge init my-project, move into the new folder, and review the default layout before changing anything.
- Write a contract. Place your Solidity files in the src folder and keep the logic small while you learn.
- Build. Run forge build to compile the contracts. Fix any compiler errors before moving on.
- Test. Add tests in the test folder and run forge test. Add fuzz tests to try a wide range of inputs.
- Start a local chain. Open a second terminal and run anvil. Leave it running while you experiment.
- Interact. Use cast to call functions or read chain data against the local node, using the address anvil prints on startup.
- Experiment with Chisel. Run chisel in a terminal to test individual Solidity expressions before adding them to a contract.
Repeat steps 2 to 4 until the tests pass, and only then consider deploying to a public network.
Pros & cons
- Covers the full Solidity workflow, from compiling to deploying, in one toolkit
- Free and open source under the MIT or Apache-2.0 license
- Anvil lets you experiment on a local node without a live network
- Built-in fuzz testing and debugging through Forge
- Installs on Windows with a single Scoop command
- Actively maintained, with a recent code update
- Command-line based, so developers used to graphical IDEs face a learning curve
- Focused on the Ethereum Virtual Machine, so it is not a fit for non-EVM chains such as Solana
- Gets the most value only for readers who already understand Solidity and smart contract concepts
- Cast can send transactions, so mistakes with keys or addresses can have real financial consequences
- Windows installation depends on Scoop, so users without it need an extra setup step
Is Foundry safe?
Foundry is a developer toolkit rather than a wallet, but Cast can send transactions and work with private keys, so treat it with the same care as any tool that touches funds. Download the program only from the official website or the GitHub repository of foundry-rs, and verify the SHA-256 checksum or signature when you install it manually. Scoop also checks the hash recorded in its manifest, which adds a layer of protection. Never paste a seed phrase or private key into a third-party website or into a tool you have not verified. While learning, use a throwaway test key and run experiments on Anvil first, which keeps mistakes away from real assets. Check the latest version on the official website to confirm you are running current code.
- Official source only. Download from getfoundry.sh. Ignore ads and lookalike domains.
- Check the SHA-256. Compare the installer hash with the value the developer publishes before running it.
- Never share your seed phrase. No developer, support agent or website — including CryptApps — will ever ask for it.
Alternatives
Foundry is a command-line toolkit, while Remix Desktop is an IDE for Solidity, so the two suit different working styles. Remix gives you a graphical environment with editing and deployment in one window, which can feel more approachable for beginners. Foundry appeals to developers who prefer scripting, automated test suites and a local node. Compared with the Solidity compiler on its own, Foundry bundles testing, deployment and chain interaction into one set of tools. Anchor serves a different ecosystem: it is a framework for Solana programs rather than Ethereum contracts. Many developers use an editor for daily work and reach for Foundry when they need repeatable tests and scripted deployments.
Specifications
- Price
- Free
- Type
- Open source
- License
- MIT|Apache-2.0
- Latest version
- 1.8.7
- Last update
- 30 Oct 2026
- Windows support
- Yes (available via Scoop)
- Official site
- getfoundry.sh
- Source code
- github.com/foundry-rs/foundry
- Install command
- scoop install foundry
Frequently asked questions
Yes. Foundry is free and open source, released under the MIT or Apache-2.0 license. You can use it for personal projects and commercial work, and you can read the source code on GitHub to see how it works. If you plan to redistribute or modify the code, review the license terms first.
The simplest way is to run scoop install foundry in PowerShell after installing Scoop. Once the command finishes, forge, cast, anvil and chisel are available in any new terminal. Updates can be applied with scoop update foundry. Manual installation is also possible if you prefer not to use a package manager.
Foundry is open source, so its code can be inspected, and it receives recent code updates. Safety depends mostly on how you use it. Verify your download, keep private keys out of scripts you do not trust, and test on Anvil before interacting with a live network.
Anvil runs a fast local Ethereum node on your computer. Developers use it to deploy contracts, run tests and try transactions without spending real funds or waiting for public network confirmations. It is typically left running in a second terminal while you work on a project.
Foundry's documentation focuses on Ethereum (ETH), and its tools are built around EVM smart contracts. Other EVM-compatible networks generally follow the same workflow, but you need to configure each network's endpoint and settings yourself before deploying.
Yes. Foundry is built for Solidity development, so you will get the most from it if you already write or read Solidity. Beginners can start with Chisel, which lets you test expressions interactively, before moving on to full projects with Forge.
Forge handles the project side: building, testing, fuzzing and deploying contracts. Cast handles the interaction side, sending transactions and reading chain data from the command line. Many workflows use Forge to produce and test contracts, then Cast to call them afterward.
Verdict
Foundry is a strong choice for developers who write Solidity and want a fast, scriptable toolkit on Windows. It is free, open source and recently updated, and its four tools cover the core loop from testing to chain interaction. It is less suitable for people who want a visual interface or who work mainly outside the EVM ecosystem. Install it through Scoop, start with Anvil and a small test project, and decide from there.