Skill Reverse Engineering

Reverse Engineering Skill

Purpose

Recover the mental model of a project from its codebase when documentation is outdated or missing.

When to Use

• Documentation-code mismatch detected
• New team member onboarding
• Post-"quick fix" cleanup

Strategy: Automated Scan + Iterative Analysis

Phase 1: Automated Directory Scan

Tool: scripts/scan_structure.py

Usage:

python3 .agent/skills/skill-reverse-engineering/scripts/scan_structure.py . --depth 2

Goal:

• Get high-level overview of project structure.
• Identify dominant languages and components.
• Avoid context overflow by NOT reading all files.

Phase 2: Local Analysis (Per-Directory)

For each key component identified in Phase 1:

1. List files.
2. Sample 2-3 representative files (read content).
3. Generate Local Summary:
   • Purpose
   • Key Classes
   • Dependencies

Phase 3: Global Synthesis

Combine local summaries to update docs/ARCHITECTURE.md:

• Update Directory Structure
• Update Component Map
• Identify Architecture Drift (Code != Docs)

Output Artifacts

1. ARCHITECTURE.md Update

Generate diffs for:

• Directory Structure
• Component Map
• Data Flow

2. KNOWN_ISSUES.md Updates

Identify:

• TODO/HACK comments indicating tech debt.
• Discrepancies between implementation and docs.

Filing format (thin index). docs/KNOWN_ISSUES.md is a hand-maintained thin index, not a flat checklist — do NOT append - [ ] lines to it. The authoritative format contract lives in the known-issues-format skill (artifact-management, TIER 0, delegates to it) — follow it:

1. If docs/KNOWN_ISSUES.md does not exist yet, materialize it from known-issues-format's assets/templates/known_issues_md_template.md first (create-if-absent).
2. File each finding as its own docs/issues/<slug>.md (frontmatter + H1 + body) plus one index line under the matching ## <category> heading — edit both in lockstep.
3. If a finding needs a category/prefix the project's ledger doesn't have yet, add a new prefix → category row to that ledger's Rules / Conventions table before filing.

(The "Append new findings, do not delete existing rationale" protection in Human Knowledge Preservation below still applies to the per-issue bodies.)

Human Knowledge Preservation

[!CAUTION] Never overwrite architectural rationale written by humans.

Protected patterns:

• <!-- HUMAN KNOWLEDGE -->
• > **Design Decision:**

Strategy: Append new findings, do not delete existing rationale.

Integration

• With skill-update-memory: After analysis, run bootstrap mode to create missing .AGENTS.md files where needed.
• Workflow 04-update-docs: Run this skill if docs drift is detected.