fuzz

Generates random and adversarial inputs to detect crashes, hangs, and invariant violations across languages using fast-check, hypothesis, and Go fuzz.

26|2|Updated Feb 12, 2026
One-click install
npx skills add https://github.com/sburl/CrossCheck --skill fuzz-sburl
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: fuzz
Source: https://github.com/sburl/CrossCheck/tree/main/codex/skills/fuzz
Command: npx skills add https://github.com/sburl/CrossCheck --skill fuzz-sburl

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

Fuzz testing automates the discovery of crashes, hangs, and invariant violations by feeding randomized and adversarial inputs into software, catching edge cases that conventional tests often miss.

Core Features & Use Cases

  • Generates random and adversarial inputs to stress parsers, validators, API handlers, state machines, and serialization code.
  • Bootstraps language-specific fuzzing tools (fast-check for JavaScript/TypeScript, hypothesis for Python, and built-in Go fuzz) and identifies fuzz targets for automated testing.
  • Produces structured reports highlighting crashes, hangs, and invariant violations to guide rapid fixes and robust software quality.

Quick Start

Run fuzz on your codebase to automatically generate random and adversarial inputs and surface crashes and invariant violations.

Frequently Asked Questions about fuzz

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

FAQPage Schema
How do I automate fuzz testing across multiple programming languages?

Automate fuzz testing by using a tool that bootstraps language-specific frameworks like fast-check for JavaScript, hypothesis for Python, and built-in Go fuzz. It discovers fuzz targets and generates random and adversarial inputs to surface crashes and invariant violations across different codebases.

What types of software bugs does property-based fuzzing find?

Property-based fuzzing finds crashes, hangs, and invariant violations by feeding randomized and adversarial inputs into software. It effectively targets edge cases in parsers, validators, API handlers, state machines, serialization, and numeric calculations that conventional tests often miss.

Can I use fuzz testing to stress my Python and JavaScript validators?

Yes, you can stress Python and JavaScript validators by applying property-based testing. The tool bootstraps hypothesis for Python and fast-check for JavaScript, automatically feeding adversarial inputs to reveal crashes and invariant violations in validation logic.

What is the best way to report invariant violations discovered during fuzz testing?

The best way to report invariant violations is by generating structured reports that highlight crashes and minimized inputs. This approach guides rapid fixes by showing the exact adversarial inputs that caused the software to fail, integrating with bug-review and redteam workflows.

Does automated fuzz testing require manual cleanup between test runs?

No, automated fuzz testing enforces cleanups between test runs automatically. This ensures that state machines and API handlers are reset properly, preventing state leakage and guaranteeing accurate crash detection and invariant violation reporting across test cycles.

How do I find existing fuzz targets in my codebase for automated testing?

Find existing fuzz targets by running the tool on your codebase to automatically discover them. It bootstraps the necessary language-specific fuzzing tools and identifies functions to test, automatically generating adversarial inputs to surface crashes without manual target configuration.