fuzzing-test

fuzzing-test is a skill for Claude Code from johnqtcg/awesome-skills. It costs 74 tokens per session (4,878 once invoked), scanned A, original, MIT.

A Go testing guide for generating fuzz tests, which repeatedly try varied inputs to find crashes and unexpected behavior. It first checks whether the code is suitable for fuzzing.

In plain words
What is it for?
It helps create Go 1.18+ fuzz tests for parsers and other suitable code, investigate crashes, set up continuous integration runs, and diagnose slow or ineffective fuzzing.
Why use it?
It prevents writing fuzz tests for targets that lack a useful way to detect incorrect results. It also helps focus testing on parser robustness, round-trip behavior, or differences between implementations.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter.

Good fit It helps create Go 1.18+ fuzz tests for parsers and other suitable code, investigate crashes, set up continuous integration runs, and diagnose slow or ineffective fuzzing.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/johnqtcg/awesome-skills/fuzzing-test
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add johnqtcg/awesome-skills --skill fuzzing-test
Clone the repo
git clone --depth 1 https://github.com/johnqtcg/awesome-skills

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for fuzzing-test

README.md
[![agentmods](https://agentmods.dev/badge/skills/johnqtcg/awesome-skills/fuzzing-test/github.svg)](https://agentmods.dev/skills/johnqtcg/awesome-skills/fuzzing-test)
Your own site
<a href="https://agentmods.dev/skills/johnqtcg/awesome-skills/fuzzing-test"><img src="https://agentmods.dev/badge/skills/johnqtcg/awesome-skills/fuzzing-test/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for fuzzing-test

Your own site · 80×15
<a href="https://agentmods.dev/skills/johnqtcg/awesome-skills/fuzzing-test"><img src="https://agentmods.dev/badge/skills/johnqtcg/awesome-skills/fuzzing-test.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 74 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,878 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 1 finding, up to medium

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • medium analysis-evasion · line 1
    Suspicious Unicode normalization or mixed-script content
    Fix: Review the flagged content for security risks. Ensure no credentials, secrets, or sensitive data are exposed.
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00074 $0.04878
Opus 5 $0.00037 $0.02439
Sonnet 5 $0.00015 $0.00976
Haiku 4.5 $0.00007 $0.00488

Measured 10d ago against content hash f8e0bae854af, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

fuzzing-test scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 10d ago.

The scan reads SKILL.md. This mod also ships 5 executable files (scripts/run_regression.sh, scripts/tests/test_golden_scenarios.py, scripts/tests/test_llm_fuzz_eval.py, …), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/fuzzing-test/SKILL.md · 485 lines

How it starts

The opening of the file, as written. The whole thing — 485 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Fuzzing Test Skill (Go)

Generate high-signal Go fuzz tests only when targets are suitable.

Quick Reference — Load References Selectively

Read the section named below first; load the reference only when its trigger applies.

When you need to… Section Load on demand
Decide if a target is suitable §Applicability Gate (run first, always) applicability-checklist.md — full decision tree, oracle forms, version gate, borderline cases
Choose among 3+ candidate targets §Target Priority Gate target-priority.md — bug-yield ranking and tie-breaks
Write the harness §Minimal Templates
Handle a discovered crash §Crash Handling crash-handling.md — triage steps, corpus policy, report template
Set up CI §CI Strategy ci-strategy.md — Actions config, corpus caching, budgets
Diagnose a slow/ineffective run, OOM, leak, or flake §Fuzz Performance Baseline advanced-tuning.md — seed quality, skip-rate, allocation profiling
Avoid or check for common mistakes §Quality Scorecard anti-examples.md — 9 BAD/GOOD harness patterns

Applicability Gate (Must Run First)

Before writing any fuzz code, evaluate suitability. If the target fails this gate, the entire remaining workflow is skipped — output the verdict, suggest alternatives, and stop.

Mark each item Pass / Fail:

  1. Target has meaningful input space (not trivial fixed-path logic).
  2. Target can be driven by Go fuzz-supported parameter types.
  3. Target has clear oracle/invariant:
    • no panic for any input
    • round-trip (decode(encode(x)) == x)
    • differential consistency
    • domain constraints/properties
  4. Target is mostly deterministic/local (not dominated by DB/network/clock/global mutable state).
  5. Target is fast enough for high-iteration fuzzing.

Hard stop — items 1, 2, and 3 are each independently blocking:

Failed item Why it stops the workflow
1 meaningful input space Fuzzing adds nothing a table-driven unit test would not find
2 fuzz-supported types Go's fuzzer cannot drive the target at all
3 clear oracle No way to recognise a bug even when the input triggers it

Read the full file on GitHub · 485 lines

Files

What ships with it

36 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 10d ago First seen · 485 lines · 74 tokens per session scan A f8e0bae854af

Subscribe to this mod's changes

fuzzing-test is a skill published in the GitHub repository johnqtcg/awesome-skills (30 stars, last pushed yesterday), licensed MIT. It adds 74 tokens to every session and 4,878 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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