foundry

Foundry Plugin

Skills with progressive disclosure for using Foundry - the blazing fast Ethereum development toolkit.

Overview

This plugin provides comprehensive skills for all core Foundry tools:

• Forge - Build, test, fuzz, debug, and deploy Solidity contracts
• Cast - Swiss Army knife for interacting with EVM chains
• Anvil - Fast local Ethereum development node

Skills

forge-testing

Write and run Solidity tests with Foundry. Covers test structure, assertions, cheatcodes, and running tests.

Use when:

• Writing unit tests for smart contracts
• Testing access control and permissions
• Verifying event emissions
• Testing revert conditions

Files:

• SKILL.md - Main skill with quick start and essential cheatcodes
• cheatcodes.md - Complete cheatcode reference (vm.prank, vm.deal, vm.warp, etc.)
• assertions.md - All assertion functions (assertEq, assertGt, assertApproxEqAbs, etc.)
• patterns.md - Common testing patterns and best practices

forge-fuzz-testing

Property-based testing with Foundry's fuzzer. Covers fuzz test structure, input constraints, fixtures, and invariant testing.

Use when:

• Testing mathematical operations for edge cases
• Finding unexpected inputs that break invariants
• Security testing for unexpected behaviors

Files:

• SKILL.md - Fuzz testing basics, constraints, and configuration
• invariants.md - Comprehensive invariant testing patterns with handlers and ghost variables

forge-deployment

Deploy and verify smart contracts with Foundry. Covers deployment scripts, verification, and multi-chain deployments.

Use when:

• Deploying contracts to testnets or mainnet
• Writing deployment scripts in Solidity
• Verifying contracts on Etherscan/Sourcify
• Managing multi-chain deployments

Files:

• SKILL.md - Quick deploy with forge create and script basics
• scripts.md - Comprehensive Solidity script patterns
• multichain.md - Multi-chain deployment strategies

cast-commands

Interact with EVM chains using Cast CLI. The Swiss Army knife for chain interaction.

Use when:

• Querying contract state (balances, storage, call results)
• Sending transactions
• Converting between data formats
• Debugging transactions

Files:

• SKILL.md - Core Cast commands reference
• patterns.md - Common Cast recipes and scripting patterns

anvil-node

Run local Ethereum nodes with Anvil for development and testing.

Use when:

• Local development and testing
• Forking mainnet or other networks
• Integration testing with frontend applications

Files:

• SKILL.md - Anvil setup, configuration, and RPC methods
• forking.md - Detailed forking patterns (impersonation, time travel, snapshots)

foundry-project

Set up and configure Foundry projects.

Use when:

• Creating new Foundry projects
• Configuring foundry.toml settings
• Managing dependencies
• Setting up remappings

Files:

• SKILL.md - Project structure, dependencies, and common tasks
• config.md - Complete foundry.toml configuration reference

Installation

Add this plugin to your Claude Code plugins:

# In your plugins directory
git submodule add https://github.com/your-org/foundry-plugin plugins/foundry

Compatibility

• Claude Code: Full support via .claude-plugin/
• OpenCode: Full support via .opencode/ symlinks

Resources

• Foundry Documentation
• Foundry GitHub
• Foundry Book

License

MIT