atheris

Automates coverage-guided fuzzing of Python code and C extensions with Atheris.

9|4|Updated Feb 7, 2026
One-click install
npx skills add https://github.com/marduk191/qwen3_mcp --skill atheris-marduk191
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: atheris
Source: https://github.com/marduk191/qwen3_mcp/tree/main/skills/testing-handbook-skills/skills/atheris
Command: npx skills add https://github.com/marduk191/qwen3_mcp --skill atheris-marduk191

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

Fuzzing helps developers find memory and robustness issues by automatically generating diverse inputs to Python code and its C extensions, reducing the time spent on manual edge-case testing.

Core Features & Use Cases

  • Coverage-guided fuzzing for Python modules and C extensions using Atheris.
  • Built-in harness instructions, installation steps, and runtime guidance for both pure Python and native extensions.
  • Use cases include identifying crashes in Python logic, fuzzing libraries that expose C extensions, and validating input validation and error handling.

Quick Start

Run the Atheris fuzzing harness to start fuzzing a Python module and its C extensions with instrumentation.

Frequently Asked Questions about atheris

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

FAQPage Schema
How do I set up coverage-guided fuzzing for Python C extensions?

Coverage-guided fuzzing for Python C extensions requires creating a fuzzing harness, configuring the runtime environment, and running instrumented tests to detect memory corruption. It provides harness creation instructions and setup guidance for both pure Python and native extensions.

What is coverage-guided fuzzing and when do I need it for Python modules?

Coverage-guided fuzzing automatically generates diverse inputs to Python code to uncover memory and robustness issues. You need it to reduce manual edge-case testing and identify crashes in Python logic, input validation, and error handling.

Can I run Atheris fuzzing in a Docker-based CI workflow?

Yes, you can run Atheris fuzzing in Docker-based CI workflows. It supports Docker-based fuzzing environments and integrates with Atheris for instrumented testing across development and CI pipelines.

Does address sanitizer work with Python fuzzing for memory corruption detection?

Address sanitizer works with Python fuzzing to detect memory corruption in C extensions. Atheris applies instrumentation to native extensions, allowing you to uncover memory issues during fuzz testing.

What's the best way to find crashes in Python logic and native extensions?

The best way to find crashes in Python logic and native extensions is coverage-guided fuzzing with Atheris. It automates input generation and instrumentation to expose memory corruption and robustness issues without manual edge-case testing.