Getting it into your agent
It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.
git clone --depth 1 https://github.com/ValorVie/custom-skillsnpx agentmods add skills/valorvie/custom-skills/reverse-engineerWrote 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.
[](https://agentmods.dev/skills/valorvie/custom-skills/reverse-engineer)<a href="https://agentmods.dev/skills/valorvie/custom-skills/reverse-engineer"><img src="https://agentmods.dev/badge/skills/valorvie/custom-skills/reverse-engineer.svg" alt="Measured on agentmods" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00065 | $0.03156 |
| Opus 5 | $0.00032 | $0.01578 |
| Sonnet 5 | $0.00013 | $0.00631 |
| Haiku 4.5 | $0.00006 | $0.00316 |
Grade A, and why
reverse-engineer 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 3d ago.
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.
How it starts
The opening of the file, as written. The whole thing — 404 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Reverse Engineering to SDD Specification Guide
Language: English | 繁體中文
Version: 1.2.0 Last Updated: 2026-01-25 Applicability: Claude Code Skills
Core Standard: This skill implements Reverse Engineering Standards. For comprehensive methodology documentation accessible by any AI tool, refer to the core standard.
Purpose
This skill guides you through reverse engineering existing code into SDD (Spec-Driven Development) specification documents, with strict adherence to Anti-Hallucination standards.
Quick Reference
Reverse Engineering Workflow
┌─────────────────────────────────────────────────────────────────┐
│ Reverse Engineering Workflow │
├─────────────────────────────────────────────────────────────────┤
│ │
│ 1️⃣ Code Analysis (AI Automated) │
│ ├─ Scan code structure, APIs, data models │
│ ├─ Parse existing tests for acceptance criteria │
│ └─ Generate draft spec (with uncertainty labels) │
│ │
│ 2️⃣ Human Input (Required) │
│ ├─ Write Motivation (why this feature exists) │
│ ├─ Add Risk Assessment │
│ └─ Verify dependencies and business context │
│ │
│ 3️⃣ Review & Confirm │
│ ├─ Discuss with stakeholders │
│ └─ Confirm [Confirmed] / [Inferred] / [Unknown] labels │
│ │
└─────────────────────────────────────────────────────────────────┘
What ships with it
3 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.
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.
- 3d ago First seen · 404 lines · 65 tokens per session scan A c4d868af4515
reverse-engineer is a skill published in the GitHub repository ValorVie/custom-skills (5 stars, last pushed 6d ago), licensed MIT. It adds 65 tokens to every session and 3,156 once invoked, about $0.0003 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 2026-09-03.
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