atheris

Fuzz Python code and C extensions to detect memory corruption and crashes.

Updated Aug 23, 2026
One-click install
npx skills add https://github.com/DobricLilujun/LabAgentSkill --skill atheris-dobriclilujun
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: atheris
Source: https://github.com/DobricLilujun/LabAgentSkill/tree/main/skillsHub/skills_scaling/testing-handbook-skills/skills/atheris
Command: npx skills add https://github.com/DobricLilujun/LabAgentSkill --skill atheris-dobriclilujun

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

Atheris fuzzing helps developers detect memory corruption and reliability issues by fuzzing Python code and C extensions.

Core Features & Use Cases

  • Coverage-guided fuzzing for Python code and native extensions
  • Harness-based testing with instrumentation decorators
  • Docker-based setup and cross-platform fuzzing guidance
  • Observability of crashes and flaky behavior
  • Integration with libFuzzer and sanitizers

Quick Start

Install Atheris, write a harness with @atheris.instrument_func, and run the fuzzer to discover crashes in your Python code or C extensions.

Frequently Asked Questions about atheris

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

FAQPage Schema
How do I fuzz Python code to find memory corruption issues?▼

You fuzz Python code by writing a harness with instrumentation decorators and running a coverage-guided fuzzer to automatically discover crashes and undefined behavior in your target package.

What is coverage-guided fuzzing for Python C extensions?▼

Coverage-guided fuzzing for Python C extensions is a software testing technique that monitors code execution paths to generate inputs capable of uncovering memory corruption and reliability issues in native code.

Can I use libFuzzer and ASAN with my Python fuzzing harness?▼

Yes, you can integrate libFuzzer and sanitizers like ASAN with your Python fuzzing harness to detect undefined behavior and memory corruption issues during the coverage-guided testing process.

How do I set up a Docker environment for fuzzing Python packages?▼

You set up a Docker environment for fuzzing Python packages by configuring a containerized workspace that supports cross-platform fuzzing guidance, allowing you to consistently build and run instrumented test harnesses.

Why does my Python fuzzer not detect crashes in native extensions?▼

Fuzzers fail to detect crashes in native extensions when harnesses lack proper instrumentation or sanitizer integration, preventing the fuzzer from observing memory corruption and flaky behavior during execution.