ba-reverse

ba-reverse is a skill for Claude Code, Codex from hiepdnh/Agentic-Development-Lifecycle. It costs 92 tokens per session (1,941 once invoked), scanned A, original, MIT.

A codebase reverse-engineering workflow for understanding an existing or inherited software project. A brownfield project is an existing system, often with old code or limited documentation.

In plain words
What is it for?
It documents the business purpose, technology stack, installed packages, important programming interfaces, and technical debt, meaning known weaknesses or maintenance problems.
Why use it?
It gives a new team a baseline before maintenance, estimates, refactoring, or a takeover from another vendor.

Skill for Claude CodeCodex

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.

agentmods
npx agentmods add skills/hiepdnh/agentic-development-lifecycle/ba-reverse
Any agent
npx skills add hiepdnh/Agentic-Development-Lifecycle --skill ba-reverse
Clone the repo
git clone --depth 1 https://github.com/hiepdnh/Agentic-Development-Lifecycle

Made for: Claude Code, Codex.

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 ba-reverse

README.md
[![agentmods](https://agentmods.dev/badge/skills/hiepdnh/agentic-development-lifecycle/ba-reverse.svg)](https://agentmods.dev/skills/hiepdnh/agentic-development-lifecycle/ba-reverse)
Your own site
<a href="https://agentmods.dev/skills/hiepdnh/agentic-development-lifecycle/ba-reverse"><img src="https://agentmods.dev/badge/skills/hiepdnh/agentic-development-lifecycle/ba-reverse.svg" alt="Measured on agentmods" height="20"></a>
Per session 92 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,941 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00092 $0.01941
Opus 5 $0.00046 $0.00971
Sonnet 5 $0.00018 $0.00388
Haiku 4.5 $0.00009 $0.00194

Measured 4d ago against content hash c17c979e786e, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

ba-reverse 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 4d 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.

.claude/skills/ba-reverse/SKILL.md · 211 lines

How it starts

The opening of the file, as written. The whole thing — 211 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Skill: /ba-reverse

Role: Business Analyst / Tech Lead
Mục đích: Onboard codebase brownfield (legacy hoặc take-over từ vendor cũ) — sinh tài liệu baseline để team VN có context trước khi nhận maintenance/feature mới.

Khi nào dùng:

  • Khách JP take-over project từ vendor khác → cần hiểu codebase trước khi commit estimate
  • Team VN inherit codebase legacy không có docs
  • Audit codebase cũ trước khi quyết định refactor / rebuild

Khi nào KHÔNG dùng: Greenfield project (dùng /ba-spec từ đầu).


Hướng dẫn thực hiện

Bước 1 — Gate: Xác định scope reverse

AskUserQuestion({
  questions: [
    {
      question: "Mục tiêu reverse engineer là gì?",
      header: "Goal",
      multiSelect: false,
      options: [
        { label: "Take-over đầy đủ", description: "Chuẩn bị nhận maintenance — cần hiểu toàn bộ" },
        { label: "Estimate scope mới", description: "Chỉ cần overview để estimate feature mới — không deep-dive" },
        { label: "Audit refactor", description: "Đánh giá technical debt để quyết định refactor/rebuild" }
      ]
    },
    {
      question: "Phạm vi codebase?",
      header: "Scope",
      multiSelect: false,
      options: [
        { label: "Toàn bộ repo", description: "Quét mọi package/module" },
        { label: "Subset cụ thể", description: "User chỉ định path/module" },
        { label: "Single service", description: "Chỉ 1 service trong monorepo" }
      ]
    }
  ]
})

Chờ confirm.

Bước 2 — Spawn subagent để scan (tránh nhồi context chính)

Dùng Explore subagent (read-only, fast) để khảo sát song song:

Agent({
  description: "Codebase scout for reverse engineering",
  subagent_type: "Explore",
  prompt: "Scan codebase tại [scope]. Tìm và report theo cấu trúc:
    1. Languages + frameworks (đọc package.json/pom.xml/requirements.txt/go.mod...)
    2. Top-level package structure (max 3 cấp)
    3. Entry points (main, server start, CLI)
    4. Database schemas (migrations folder, ORM models)
    5. External integrations (API clients, SDK imports)
    6. Test coverage signals (test folder size, CI config)
    7. Code quality red flags (TODO/FIXME density, file size outliers)
  Report dưới 600 từ, kèm file path:line cho mỗi finding quan trọng."
})

Read the full file on GitHub · 211 lines

Files

What ships with it

2 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. 4d ago First seen · 211 lines · 92 tokens per session scan A c17c979e786e

Subscribe to this mod's changes

ba-reverse is a skill published in the GitHub repository hiepdnh/Agentic-Development-Lifecycle (6 stars, last pushed 7d ago), licensed MIT. It adds 92 tokens to every session and 1,941 once invoked, about $0.0005 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 2026-08-31.

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