fizz

Generate and run fuzz tests for Solidity smart contracts using Echidna and Medusa.

1.1k|190|Updated Feb 23, 2026

Search Tags:#security #smart contracts #Medusa #Solidity #fuzz testing #Echidna

Ready to run

npx skills add https://github.com/pashov/skills --skill fizz

💬 Prompt for ChatGPT / Claude Chat▼

Please help me install this Agent Skill.
Skill: fizz
Source: https://github.com/pashov/skills/tree/main/fizz
Command: npx skills add https://github.com/pashov/skills --skill fizz

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill requires echidna, medusa, foundry, hardhat, and includes scripts (resource) and references (resource) and assets (resource) components.

What problem does it solve?

This Skill automates the process of fuzz testing smart contracts, saving time and effort for Solidity developers and security researchers.

Core Features & Use Cases

Automated Fuzz Testing: Generates and runs fuzz tests for Solidity smart contracts using Echidna and Medusa.
Foundry/Hardhat Support: Works with projects developed using either Foundry or Hardhat frameworks.
Use Case: Generate a fuzz suite for your lending protocol to test for solvency and liquidation invariants, saving days of manual setup.

Quick Start

Generate a fuzz suite for your project by running the 'fizz' skill.

Frequently Asked Questions about fizz

High-intent search queries and answers about installing and using this skill.

FAQPage Schema

How do I automate fuzz testing for Solidity smart contracts?▼

You can automate fuzz testing for Solidity smart contracts by generating and executing test suites that check security invariants using Echidna and Medusa, specifically targeting Foundry and Hardhat projects.

Can I use Echidna and Medusa fuzz tests with a Hardhat project?▼

Yes, automated fuzz tests using Echidna and Medusa fully support Hardhat projects, allowing you to generate and execute invariant test suites without manual framework conversion.

What do I need to run automated invariant testing on Solidity protocols?▼

To run automated invariant testing on Solidity protocols, you need Echidna and Medusa for invariant execution, and Foundry for smart contract compilation and debugging.

What is the best way to test lending protocol solvency invariants in Solidity?▼

The best way to test lending protocol solvency invariants is to generate an automated fuzz suite that runs random inputs against your contracts to validate liquidation and solvency rules.

Does automated fuzz testing work with both Foundry and Hardhat frameworks?▼

Yes, automated fuzz testing works with both Foundry and Hardhat frameworks, utilizing Foundry for compilation and debugging while running invariant tests via Echidna and Medusa.

Why do I need Foundry installed if I am using Medusa for fuzz testing?▼

Foundry is required because it handles smart contract compilation and debugging, while Medusa focuses specifically on executing the fuzz tests and validating security invariants.