Skip to content
appsgit

Property Based Testing

Property Based Testing is an agent skill (a SKILL.md file) from trailofbits/skills. Writes, reviews, and debugs property-based tests — Hypothesis, fast-check, proptest, jqwik, rapid, and Echidna or Medusa for Solidity invariants. It works with Claude Code and Codex and has 7,804 GitHub stars across a repository of 4 listed skills.

github.com/trailofbits/skills/plugins/property-based-testing/skills/property-based-testing (opens in a new tab)

Data as of from the GitHub API and skills.sh; description from the skill's SKILL.md. Report an error

View on GitHub (opens in a new tab)View on skills.sh (opens in a new tab)

Add this skill

Claude

This repository is a Claude Code plugin marketplace. In Claude Code:

/plugin marketplace add trailofbits/skills
/plugin install property-based-testing@trailofbits

In the Claude apps, zip the property-based-testing folder and upload it under Customize > Skills > + > Upload a skill (code execution must be on).

ChatGPT / Codex

Codex reads skills from .agents/skills/ in a repo or ~/.agents/skills/ for every project:

git clone --depth 1 https://github.com/trailofbits/skills.git
cp -r skills/plugins/property-based-testing/skills/property-based-testing .agents/skills/property-based-testing   # repo; ~/.agents/skills for all projects

Standalone skills also load in the ChatGPT desktop app.

Cursor

Cursor loads skills from .cursor/skills/ (or ~/.cursor/skills/) and also reads .claude/skills/:

git clone --depth 1 https://github.com/trailofbits/skills.git
cp -r skills/plugins/property-based-testing/skills/property-based-testing .cursor/skills/property-based-testing   # project; ~/.cursor/skills for all projects

Source (checked Oct 7, 2026): code.claude.com/docs/en/skills (opens in a new tab), code.claude.com/docs/en/plugin-marketplaces (opens in a new tab), support.claude.com/en/articles/12512180-using-skills-in-claude (opens in a new tab), learn.chatgpt.com/docs/build-skills (opens in a new tab), cursor.com/docs/context/skills (opens in a new tab)

What this skill does

Writes, reviews, and debugs property-based tests — Hypothesis, fast-check, proptest, jqwik, rapid, and Echidna or Medusa for Solidity invariants. Use whenever tests should cover a whole input domain instead of a hand-picked list of examples: encode/decode and serialize/deserialize pairs, parsers, canonicalizers and normalizers, validators, numeric and Decimal types, comparators and sort order, data structures, and smart-contract state invariants.

When it triggers

  • use when adding cases to an existing @given, fast-check, or proptest suite, when judging whether existing property tests assert anything real, and when a generator has shrunk a counterexample and you need to tell a wrong property from a gen

More skills in trailofbits/skills

4 skills are listed from this repository.

Similar skills

More testing & qa skills

All Testing & QA

FAQ

Property Based Testing FAQ

Still curious? Email info@appsgit.com.

How do I install the Property Based Testing skill?

In Claude Code, run /plugin marketplace add trailofbits/skills and then /plugin install property-based-testing@trailofbits. For Codex or Cursor, copy the property-based-testing folder into .agents/skills/ or .cursor/skills/.

Is the Property Based Testing skill free?

Yes. The repository is open source under the CC-BY-SA-4.0 license.

Is Property Based Testing maintained?

The repository's most recent commit was on Oct 23, 2026. appsgit only lists skills from repositories with a commit in the last six months.