---
title: "Atheris - Air Market"
description: "Fuzzing is usually talked about for C and C++, but Python code has bugs that odd input will find too. Atheris is a coverage-guided fuzzer for Python, and it also handles C extensions. Reach for it wh…"
canonical: "https://airmarket.ai/app/atheris"
---

[Air Market](/) / [Security](/category/security) / Atheris

Skill by [Trail of Bits](/@trailofbits)

# Atheris

Fuzz Python code, including the parts written in C

## What this does

Fuzzing is usually talked about for C and C++, but Python code has bugs that odd input will find too. Atheris is a coverage-guided fuzzer for Python, and it also handles C extensions. Reach for it when the project you want to fuzz is Python.

### Top 3 things it does for you

- Fuzz pure Python code
- Fuzz a Python C extension
- Run coverage-guided fuzzing on a Python project

## Information

**Atheris at a glance**

|  |  |
| --- | --- |
| Kind | Skill |
| Publisher | [Trail of Bits](/@trailofbits) |
| Category | [Security](/category/security) |
| Works with | Agent Skills - an open standard supported by 40+ agents |
| Size | 17 KB |
| Licence | CC-BY-SA-4.0 |
| Repository | [trailofbits/skills](https://github.com/trailofbits/skills/tree/d5fe2e6a7896236c3102fd5477e833623ad70298/plugins/testing-handbook-skills/skills/atheris) |
| GitHub stars | 6,823 (as of Nov 2026) |
| Installs | 5,573, counted by skills.sh (Nov 2026) |

## Security report

**Verified.** AIR scanned this exact version of Atheris and flagged nothing. AIR's verdict: **safe**.

**What Atheris's check was run against**

|  |  |
| --- | --- |
| Commit | d5fe2e6a7896236c3102fd5477e833623ad70298 |
| Content hash | e7e182e5f17dfe90828c6001f33b88bd74a968abd15366bfcfce057763b8b68a |
| Files read | [Browse the files at this exact commit](https://github.com/trailofbits/skills/blob/d5fe2e6a7896236c3102fd5477e833623ad70298/plugins/testing-handbook-skills/skills/atheris/SKILL.md) |

A scan is named by the exact content it read, not by a version number. A different version is a different artifact, and nothing here applies to a version AIR has not scanned.

[Read the full security report for Atheris](/security/atheris)

## About Atheris

Atheris is a coverage-guided Python fuzzer based on libFuzzer. Use it for fuzzing pure Python code and Python C extensions.

## What's inside

- SKILL.md - instructions
- agents/openai.yaml - data
- assets/trail-of-bits-mark.svg - template

## Questions

### Is Atheris safe to install?

AIR scanned this exact version of Atheris and flagged nothing. AIR's verdict: safe. The verdict is named by the content that was read, at commit d5fe2e6a7896, so it cannot drift onto a version nobody scanned. The full report is at https://airmarket.ai/security/atheris.

### How do I install Atheris?

Open https://airmarket.ai/app/atheris on Air Market and use the install action: Air Market hands Claude a prompt naming this exact skill, and Claude sets it up. Source, pinned to the exact commit this listing describes: https://github.com/trailofbits/skills/tree/d5fe2e6a7896236c3102fd5477e833623ad70298/plugins/testing-handbook-skills/skills/atheris. Install from that link, not the branch.

## Related on Air Market

- [More Security listings](/category/security)
- [Everything by Trail of Bits](/@trailofbits)

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Canonical URL: <https://airmarket.ai/app/atheris>