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Open-Source Testing · foundry-rs

foundry

Foundry is a Rust-based toolkit for building and testing Ethereum smart contracts, combining a compiler (Forge), transaction tool (Cast), local development node (Anvil), and Solidity REPL (Chisel). It emphasizes speed, modularity, and cross-platform support for Solidity and Vyper development.

Source: GitHub — github.com/foundry-rs/foundry
10.5k
GitHub stars
2.6k
Forks
Rust
Primary language
Apache-2.0
License (OSI-approved)

Key facts

Objective fields from the source. Values we can't verify are shown as “Unknown” rather than guessed.

FieldValue
Repositoryfoundry-rs/foundry
Ownerfoundry-rs
Primary languageRust
LicenseApache-2.0 — OSI-approved
Stars10.5k
Forks2.6k
Open issues435
Latest releasev1.7.1 (2026-05-08)
Last updated2026-07-08
Sourcehttps://github.com/foundry-rs/foundry

What foundry is

Foundry provides modular Rust components for the Ethereum development lifecycle: Forge handles contract compilation, testing, fuzzing, and deployment; Cast offers EVM interaction and RPC querying; Anvil runs a local EVM node with forking capability; Chisel provides interactive Solidity evaluation. Architecture is built on the Alloy library for Ethereum primitives.

Quickstart

Get the foundry source

Clone the repository and explore it locally.

terminalbash
git clone https://github.com/foundry-rs/foundry.gitcd foundry# follow the project's README for install & configuration

Need it deployed, integrated, or customized instead? DEV.co ships production installs.

Best use cases

Solidity Smart Contract Testing & Fuzzing

Forge supports property-based fuzzing and fast test execution in Rust, making it ideal for teams building secure, well-tested smart contracts at scale.

Local Ethereum Development & Forking

Anvil provides a lightweight local EVM node with mainnet fork support, reducing setup friction for contract development and integration testing workflows.

Ethereum RPC Scripting & Chain Interaction

Cast serves as a command-line Swiss Army knife for querying blockchain state, sending transactions, and composing complex interactions without custom scripting.

Implementation considerations

  • Requires Rust toolchain installation; adds compilation step and dependency management overhead compared to JavaScript-based tools like Hardhat.
  • Learning curve steeper for teams unfamiliar with Rust or CLI-driven development; documentation assumes some Ethereum and Solidity proficiency.
  • Fuzzing and advanced testing features are powerful but require deliberate test design; poorly written fuzz tests may not surface vulnerabilities effectively.
  • Integration with external services (block explorers, RPC providers) relies on Cast; verify RPC endpoint reliability and rate limits before production use.
  • Version management via foundryup; pin versions in CI/CD pipelines to avoid unexpected behavior changes across team members.

When to avoid it — and what to weigh

  • Non-Solidity/Vyper Smart Contract Ecosystems — Foundry is tightly coupled to Solidity and Vyper; unsuitable for Move, Rust on-chain, or other VM languages.
  • Enterprise Support Requirements — This is a community-driven open-source project. No commercial SLA, dedicated support, or vendor backing is available.
  • Windows-First Development Environment — While Foundry supports Windows, it is optimized for Unix-like systems; Windows adoption may encounter friction or undocumented edge cases.
  • Graphical IDE Preference — Foundry is CLI-centric. Teams requiring visual contract deployment, debugging GUIs, or integrated IDE plugins should evaluate alternatives like Hardhat or Remix.

License & commercial use

Dual-licensed under Apache License 2.0 (primary) and MIT license. Both are OSI-compliant, permissive licenses. Contributions are automatically dual-licensed unless explicitly stated otherwise.

Apache 2.0 and MIT are permissive OSI licenses that explicitly permit commercial use, modification, and distribution without royalty or additional licensing restrictions. No commercial entity owns Foundry; use is unrestricted provided license terms are acknowledged. However, no vendor guarantees, support contracts, or indemnification are included; users assume all liability and maintenance burden.

DEV.co evaluation signals

Editorial assessment — not user reviews. Directional, with an explicit confidence level.

SignalAssessment
MaintenanceActive
DocumentationStrong
License clarityClear
Deployment complexityLow
DEV.co fitGood
Assessment confidenceHigh
Security considerations

Foundry itself does not execute untrusted code; it is a compilation and testing framework. Key risks: (1) Private key exposure via environment variables or scripts—apply standard OS-level secrets management. (2) RPC endpoint compromise affects transaction reliability—use trusted, rate-limited providers. (3) Fuzzing and testing do not guarantee contract soundness—formal verification and external audits remain necessary. (4) Anvil's local fork mode does not replicate all mainnet consensus rules; use with caution for state-dependent contracts. Review SECURITY.md for release verification procedures.

Alternatives to consider

Hardhat (JavaScript/TypeScript)

Similar feature set (testing, debugging, local node) with lower barrier to entry for Node.js teams; larger ecosystem of plugins; IDE integration simpler. Trade-off: slower execution and higher memory footprint.

Truffle (JavaScript/Solidity)

Mature ecosystem, extensive Solidity debugging, and native Windows support. Trade-off: declining community adoption, slower builds, less active maintenance than Foundry.

Remix (Web-based IDE)

Zero-setup visual environment for contract development, testing, and deployment. Trade-off: limited scalability for complex projects, no command-line integration, slower for large test suites.

Software development agency

Build on foundry with DEV.co software developers

Ready to accelerate Solidity testing and contract development? Our Ethereum engineering team can help you migrate from Hardhat, establish best practices with Foundry, and integrate it into your CI/CD pipeline.

Talk to DEV.co

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foundry FAQ

Is Foundry production-ready?
Yes, Foundry is widely used in production by teams at Paradigm, Uniswap Labs, and others. However, it is community-supported; conduct your own audits and testing before mainnet deployment.
Can Foundry replace Hardhat entirely?
Functionally, yes, for most Solidity projects. Migration requires rewriting tests and scripts from JavaScript to Solidity/Rust. Team familiarity with Rust and CLI tooling is a prerequisite.
What is the performance difference vs. Hardhat?
Foundry's Rust backend compiles and executes tests significantly faster (often 5–10x for large suites). Benchmarks at getfoundry.sh provide specific comparisons.
How does Foundry handle contract dependencies?
Via git submodules or Soldeer package manager. Dependencies are compiled alongside your code; version management is explicit and reproducible.

Software developers & web developers for hire

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Evaluate Foundry for Your Ethereum Development

Ready to accelerate Solidity testing and contract development? Our Ethereum engineering team can help you migrate from Hardhat, establish best practices with Foundry, and integrate it into your CI/CD pipeline.