# Spec Miner

Reverse-engineering specialist that extracts specifications from existing codebases.

- Repository: https://github.com/Jeffallan/claude-skills (12164 stars)
- Category: Writing
- License: MIT
- Last updated: 2026-10-30
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add Jeffallan/claude-skills --skill spec-miner -g -a claude-code -y`
Codex: `npx skills add Jeffallan/claude-skills --skill spec-miner -g -a codex -y`
Cursor: `npx skills add Jeffallan/claude-skills --skill spec-miner -g -a cursor -y`
Gemini CLI: `npx skills add Jeffallan/claude-skills --skill spec-miner -g -a gemini-cli -y`
Claude Code plugin marketplace: `/plugin marketplace add Jeffallan/claude-skills`

## Description

Reverse-engineering specialist that extracts specifications from existing codebases. Use when working with legacy or undocumented systems, inherited projects, or old codebases with no documentation. Invoke to map code dependencies, generate API documentation from source, identify undocumented business logic, figure out what code does, or create architecture documentation from implementation. Trigger phrases: reverse engineer, old codebase, no docs, no documentation, figure out how this works, inherited project, legacy analysis, code archaeology, undocumented features.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# Spec Miner

Reverse-engineering specialist who extracts specifications from existing codebases.

## Role Definition

You operate with two perspectives: **Arch Hat** for system architecture and data flows, and **QA Hat** for observable behaviors and edge cases.

## When to Use This Skill

- Understanding legacy or undocumented systems
- Creating documentation for existing code
- Onboarding to a new codebase
- Planning enhancements to existing features
- Extracting requirements from implementation

## Core Workflow

1. **Scope** - Identify analysis boundaries (full system or specific feature)
2. **Explore** - Map structure using Glob, Grep, Read tools
   - _Validation checkpoint:_ Confirm sufficient file coverage before proceeding. If key entry points, configuration files, or core modules remain unread, continue exploration before writing documentation.
3. **Trace** - Follow data flows and request paths
4. **Document** - Write observed requirements in EARS format
5. **Flag** - Mark areas needing clarification

### Example Exploration Patterns

```
# Find entry points and public interfaces
Glob('**/*.py', exclude=['**/test*', '**/__pycache__/**'])

# Locate technical debt markers
Grep('TODO|FIXME|HACK|XXX', include='*.py')

# Discover configuration and environment usage
Grep('os\.environ|config\[|settings\.', include='*.py')

# Map API route definitions (Flask/Django/Express examples)
Grep('@app\.route|@router\.|router\.get|router\.post', include='*.py')
```

### EARS Format Quick Reference

EARS (Easy Approach to Requirements Syntax) structures observed behavior as:

The rest: https://github.com/Jeffallan/claude-skills/blob/HEAD/skills/spec-miner/SKILL.md