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atheris
65 / 100 · Review before installing
Check before installing. Some of what it can do is expected: a coding skill usually runs build and test commands.
By trailofbits/skills (GitHub) · coding · 8,130 stars · scanned at commit e4dd0bb
Sets up and runs Atheris, the coverage-guided Python fuzzer built on libFuzzer. Covers TestOneInput harnesses, FuzzedDataProvider, instrumenting both pure Python and native C extensions, and running under AddressSanitizer. Use when fuzzing a Python package, hunting memory corruption in a Python C extension, or choosing between Atheris and Hypothesis for a Python target.
Works with any agent that supports SKILL.md skills.
What this skill can do
Runs commands on your computer
The author does not mention this. Expected for a coding skill.
Found in 17 places.
Show 14 more
- plugins/testing-handbook-skills/skills/atheris/SKILL.md, line 141
python -c "import atheris; print(atheris.__version__)" - plugins/testing-handbook-skills/skills/atheris/SKILL.md, line 238
export CC="clang" - plugins/testing-handbook-skills/skills/atheris/SKILL.md, line 249
CBOR2_BUILD_C_EXTENSION=1 uv add --no-binary-package cbor2 'cbor2==5.6.4' - plugins/testing-handbook-skills/skills/atheris/SKILL.md, line 282
uv run python cbor2-fuzz.py - plugins/testing-handbook-skills/skills/atheris/SKILL.md, line 292
mkdir corpus - plugins/testing-handbook-skills/skills/atheris/SKILL.md, line 300
uv run python fuzz.py corpus/ - plugins/testing-handbook-skills/skills/atheris/SKILL.md, line 307
uv run python fuzz.py -merge=1 new_corpus/ old_corpus/ - plugins/testing-handbook-skills/skills/atheris/SKILL.md, line 318
uv run python fuzz.py - plugins/testing-handbook-skills/skills/atheris/SKILL.md, line 324
uv run python fuzz.py corpus/ - plugins/testing-handbook-skills/skills/atheris/SKILL.md, line 331
uv run python fuzz.py -max_total_time=600 - plugins/testing-handbook-skills/skills/atheris/SKILL.md, line 358
export CFLAGS="-fsanitize=address,fuzzer-no-link" - plugins/testing-handbook-skills/skills/atheris/SKILL.md, line 364
export ASAN_OPTIONS="allocator_may_return_null=1,detect_leaks=0" - plugins/testing-handbook-skills/skills/atheris/SKILL.md, line 371
export LD_PRELOAD="$(python -c 'import atheris; import os; print(os.path.join(os.path.dirname(atheris.__file__), "asan_with_fuzzer.so"))')" - plugins/testing-handbook-skills/skills/atheris/SKILL.md, line 424
export CFLAGS="-fsanitize=address,undefined,fuzzer-no-link"
Downloads and installs other software
The author does not mention this.
Found in 3 places.
Changes files outside its own folder
The author does not mention this.
Found in 3 places.
Sends data to these websites: apt.llvm.org
The author does not mention this.
Found in 1 place.
Safer alternatives
Low-risk skills in the same category (coding) that look related. Check that one does what you need.
Install
Paste this into your terminal. It downloads exactly the version we scanned, not whatever is newest.
if [ -e ~/.agents/skills/'atheris' ] || [ -L ~/.agents/skills/'atheris' ]; then echo 'A skill folder named atheris already exists — not replacing it' >&2; false; else d=$(mktemp -d) && git clone --quiet --filter=blob:none --no-checkout 'https://github.com/trailofbits/skills' "$d" && git -C "$d" checkout --quiet 'e4dd0bb5b15535f7c5a0834187dffba6ac37e4ff' -- 'plugins/testing-handbook-skills/skills/atheris' && mkdir -p ~/.agents/skills && cp -R "$d"/'plugins/testing-handbook-skills/skills/atheris' ~/.agents/skills/'atheris' && rm -rf "$d"; fi
Codex reads ~/.agents/skills directly. For Claude Code, Cursor, Copilot, Gemini CLI, Antigravity or OpenCode, also link it. For Claude Code: ln -s ~/.agents/skills/'atheris' ~/.claude/skills/'atheris' (other agents: ~/.cursor/skills, ~/.copilot/skills, ~/.gemini/skills, ~/.gemini/config/skills, ~/.config/opencode/skills). Or install through the finder skill, which does both.
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Score history
| Date | Version | Score |
|---|
| 2026-11-08 | e4dd0bb | 65 |
| 2026-11-07 | e4dd0bb | 65 |